The document studies the moisture depletion pattern of spinach dried in a hot air oven. It finds that:
1) Drying time decreases significantly with increasing air temperature from 55°C to 75°C.
2) Pretreating spinach with blanching does not affect the drying rate.
3) Drying occurs entirely in the falling rate period, validating the use of exponential models.
4) Loading density and pretreatment have insignificant effects on drying rate, especially at higher temperatures.
5) Moisture ratio decreases exponentially over time, following the exponential law better at higher temperatures.
Transport properties of Gum mediated synthesis of Indium Oxide (In2O3) Nano f...IJERA Editor
Two- Step method has been applied to prepare stable In2O3 nano fluids in Ethylene Glycol with PVP (Polyvinyl pyrrolidone) used as stabilizing agent having In2O3 concentrations of 1% by volume, where the In2O3 nano particles are obtained by biosynthesis of Indium (III) Acetyl Acetonate and Gum Acacia. Since the two-step method is more versatile as it provides the opportunity to disperse a wide variety of nano particles in different types of base fluids. The nano fluids were characterised by UV-vis spectroscopy, FTIR, SEM, EDAX, and TEM, and systematically investigated for Thermal conductivity (TC), density, viscosity, specific gravity and electrical conductivity for different polymer concentrations. The size of nano particles was found to be in the range of 5-30nm for two different nano particle to PVP ratios. For higher concentration of polymer in nano fluid, nano particles were 20nm in size showing increase in Thermal conductivity but a decrease in density and viscosity which is due to the polymer structure around nano particles. It is observed that the viscosity, density & specific gravity increases with the increase in PVP concentration and decreases with temperature. The thermal conductivity measurements of nano fluids show substantial increment relative to the base fluid (Ethylene glycol). Effect of PVP Polymer on viscosity, density, specific gravity can have a significant effect on magnitude and behaviour of the Thermal conductivity enhancement confirming the Newtonian behaviour of nano fluid. This offers tremendous scope for developing compact and effective heat transfer equipment. An enhancement of 20-25% for 1:5 volume concentration are observed at an average voltage of 60V when compared with EG (Ethylene glycol) at the same voltage. This method is simple, fast and reliable for the synthesis of Newtonian nano fluids containing In2O3 nano particles.
Study of Combustion Characteristics of Fuel Briquettesijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
This document summarizes a study on the influence of thermal distress on the flexural strength of laminated cement composites. Specimens with 1-5 reinforcement layers were subjected to 0-120 thermal cycles consisting of 24 hours at 110°C and 24 hours at 15°C. Control specimens were cured similarly but at 15°C. Testing found that flexural strength increased with cycles for all specimens, and strengths were higher for thermally distressed specimens compared to controls. Thermal distress altered composite behavior and led to increased strength.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
EFFECT OF (MGO) NANOFLUID ON HEAT TRANSFER CHARACTERISTICS FOR INTEGRAL FINNE...IAEME Publication
Experimental investigations have been carried out in this paper to study the enhancement of heat transfer characteristics for cross flow low integral finned tube heat exchanger with using of (MgO) nanofluid. The study includes designing and manufacturing of test section from Pyrex glass with dimensions (2505001200) mm width, height and length, respectively. has a single copper tube with eight passes.. The low integral finned tube with (19 mm) inner diameter, (21 mm) root diameter and (24 mm) outer diameter. The fin height is (1.5 mm), thickness (1 mm) and the pitch is (2 mm). Air was used as a cooling fluid passing across the test tube with a range of velocities (1, 2, 3 and 4) m/sec. The inner side flow rates with a range of (2, 3, 4, 5 and 6) L/min. for water and for nanofluid.
This document summarizes research on modeling the thermal kinetics of thin layer drying of Indian gooseberry (aonla) flakes. Experiments were conducted drying aonla flakes at air velocities of 0.48m/s, temperatures ranging from 40-75°C, and relative humidity of 35%. Moisture content was measured periodically to calculate moisture ratios. Various drying models (Newton, Page, Modified Page) were evaluated based on their ability to predict experimental moisture values using statistical measures like RMSE, chi-square, and efficiency. The Modified Page model with an exponent of 1 provided the best fit to experimental data with minimum RMSE and chi-square values and maximum efficiency. Correlations were developed between drying coefficient (k) and shape
Estimation of Mass Transfer Parameters and Drying Characteristics of Black Pe...AM Publications
Drying characteristics of black pepper with an initial moisture content of 59.98% (kg moisture/kg wet sample)
was carried out in a domestic microwave oven at five different powers of 900W, 720W, 540W, 360W and 180W. The drying
curves were plotted and from the rate vs moisture content curves it could be concluded that the complete drying process had
took place in the falling rate period. Experimental data were fitted to the thirteen thin layer drying models available in the
literature. Midilli et al model was found to be the best model to describe the microwave thin layer drying of black pepper.
The effective diffusivities were estimated by using Fick’s second law of diffusion for spherical particles. Mass transfer
coefficients and mass Biot numbers were also calculated for the five microwave powers. The effective diffusivities, mass
transfer coefficients and the mass Biot numbers varied between 1.144*10-10to 4.575*10-9 m2/s, 0.863 to 8.47 m/s and 84.5*
105 to 20.7* 105 for the microwave powers studied. Effective diffusivities and mass transfer coefficient increased with the
increasing microwave power where as the mass Biot numbers decreased with the increasing microwave power.
Comparison of kinetic models for biogas production rate from saw dusteSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Transport properties of Gum mediated synthesis of Indium Oxide (In2O3) Nano f...IJERA Editor
Two- Step method has been applied to prepare stable In2O3 nano fluids in Ethylene Glycol with PVP (Polyvinyl pyrrolidone) used as stabilizing agent having In2O3 concentrations of 1% by volume, where the In2O3 nano particles are obtained by biosynthesis of Indium (III) Acetyl Acetonate and Gum Acacia. Since the two-step method is more versatile as it provides the opportunity to disperse a wide variety of nano particles in different types of base fluids. The nano fluids were characterised by UV-vis spectroscopy, FTIR, SEM, EDAX, and TEM, and systematically investigated for Thermal conductivity (TC), density, viscosity, specific gravity and electrical conductivity for different polymer concentrations. The size of nano particles was found to be in the range of 5-30nm for two different nano particle to PVP ratios. For higher concentration of polymer in nano fluid, nano particles were 20nm in size showing increase in Thermal conductivity but a decrease in density and viscosity which is due to the polymer structure around nano particles. It is observed that the viscosity, density & specific gravity increases with the increase in PVP concentration and decreases with temperature. The thermal conductivity measurements of nano fluids show substantial increment relative to the base fluid (Ethylene glycol). Effect of PVP Polymer on viscosity, density, specific gravity can have a significant effect on magnitude and behaviour of the Thermal conductivity enhancement confirming the Newtonian behaviour of nano fluid. This offers tremendous scope for developing compact and effective heat transfer equipment. An enhancement of 20-25% for 1:5 volume concentration are observed at an average voltage of 60V when compared with EG (Ethylene glycol) at the same voltage. This method is simple, fast and reliable for the synthesis of Newtonian nano fluids containing In2O3 nano particles.
Study of Combustion Characteristics of Fuel Briquettesijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
This document summarizes a study on the influence of thermal distress on the flexural strength of laminated cement composites. Specimens with 1-5 reinforcement layers were subjected to 0-120 thermal cycles consisting of 24 hours at 110°C and 24 hours at 15°C. Control specimens were cured similarly but at 15°C. Testing found that flexural strength increased with cycles for all specimens, and strengths were higher for thermally distressed specimens compared to controls. Thermal distress altered composite behavior and led to increased strength.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
EFFECT OF (MGO) NANOFLUID ON HEAT TRANSFER CHARACTERISTICS FOR INTEGRAL FINNE...IAEME Publication
Experimental investigations have been carried out in this paper to study the enhancement of heat transfer characteristics for cross flow low integral finned tube heat exchanger with using of (MgO) nanofluid. The study includes designing and manufacturing of test section from Pyrex glass with dimensions (2505001200) mm width, height and length, respectively. has a single copper tube with eight passes.. The low integral finned tube with (19 mm) inner diameter, (21 mm) root diameter and (24 mm) outer diameter. The fin height is (1.5 mm), thickness (1 mm) and the pitch is (2 mm). Air was used as a cooling fluid passing across the test tube with a range of velocities (1, 2, 3 and 4) m/sec. The inner side flow rates with a range of (2, 3, 4, 5 and 6) L/min. for water and for nanofluid.
This document summarizes research on modeling the thermal kinetics of thin layer drying of Indian gooseberry (aonla) flakes. Experiments were conducted drying aonla flakes at air velocities of 0.48m/s, temperatures ranging from 40-75°C, and relative humidity of 35%. Moisture content was measured periodically to calculate moisture ratios. Various drying models (Newton, Page, Modified Page) were evaluated based on their ability to predict experimental moisture values using statistical measures like RMSE, chi-square, and efficiency. The Modified Page model with an exponent of 1 provided the best fit to experimental data with minimum RMSE and chi-square values and maximum efficiency. Correlations were developed between drying coefficient (k) and shape
Estimation of Mass Transfer Parameters and Drying Characteristics of Black Pe...AM Publications
Drying characteristics of black pepper with an initial moisture content of 59.98% (kg moisture/kg wet sample)
was carried out in a domestic microwave oven at five different powers of 900W, 720W, 540W, 360W and 180W. The drying
curves were plotted and from the rate vs moisture content curves it could be concluded that the complete drying process had
took place in the falling rate period. Experimental data were fitted to the thirteen thin layer drying models available in the
literature. Midilli et al model was found to be the best model to describe the microwave thin layer drying of black pepper.
The effective diffusivities were estimated by using Fick’s second law of diffusion for spherical particles. Mass transfer
coefficients and mass Biot numbers were also calculated for the five microwave powers. The effective diffusivities, mass
transfer coefficients and the mass Biot numbers varied between 1.144*10-10to 4.575*10-9 m2/s, 0.863 to 8.47 m/s and 84.5*
105 to 20.7* 105 for the microwave powers studied. Effective diffusivities and mass transfer coefficient increased with the
increasing microwave power where as the mass Biot numbers decreased with the increasing microwave power.
Comparison of kinetic models for biogas production rate from saw dusteSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Cost Effective Experimental Setup for Gas Sensing Applicationsiosrjce
IOSR Journal of Applied Chemistry (IOSR-JAC) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Investigation on the activating effect of na2 co3 and naoh on slageSAT Publishing House
This document investigates the activating effect of sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) on the workability and compressive strength of alkali-activated slag materials. Heat release experiments show that slag activated with Na2CO3 reacts much slower than slag activated with NaOH, with the main reaction occurring around 40 hours after mixing compared to 30 minutes for NaOH. Testing of workability and 7-day compressive strength was done with different alkali dosages and water-to-binder ratios. In general, Na2CO3 provided higher fluidity and strength compared to NaOH under the same conditions.
Effect of water temperature on the mechanical properties of water quenched me...Alexander Decker
This document summarizes a study on the effect of water temperature on the mechanical properties of medium carbon steel samples quenched in water. Two steel samples with carbon contents of 0.33% and 0.42% were heated to 900°C and quenched in water ranging from 35°C to 95°C. Results showed hardness was reduced by over 18% and impact strength improved by over 50% at higher water temperatures, as the hard martensite structure was replaced with tempered martensite. Maximum hardness occurred at a water temperature of 65°C while maximum impact strength and tensile properties occurred at 95°C. The study concluded water quenching at higher temperatures can improve steel toughness with only slight
This document summarizes a standard test method for measuring the thermal transmission properties of thermally conductive electrical insulation materials. It describes measuring a material's thermal impedance using a test setup with two parallel isothermal surfaces that impose a temperature gradient on a test specimen in between. Measurements of the surface temperatures and heat flow rate are used to calculate the specimen's thermal impedance and apparent thermal conductivity. The test method can be used to evaluate liquids, gels, rubbers, ceramics, metals and some plastics. Adjusting the clamping pressure and applying thermal grease can help account for interfacial thermal resistance between the specimen and test surfaces.
In the recent research activities, the nanofluids have involved a great deal
attention since their superior report in thermal performance and many other
applications. Now a days cooling process is a great challenge in most of the chemical
process, Nuclear reactor, automobile radiator, micro electronics systems. To meet out
this, a novel coolant (Nano fluids) was developed by choi.S.U.S 1995 at Argonne
National lab. USA. In continuation to his work, water based alumina Nano fluids was
prepared and applied in shell and tube heat exchanger to analyze the heat transfer
rate. The same analysis is discussed with conventional base fluid of water and
alumina nanofluid also this presents the characterization of Alumina Nano particle by
means of XRD and SEM.
Investigation on effective thermal conductivity of foams using transient plan...eSAT Publishing House
The document describes an experimental setup used to determine the effective thermal conductivity of various foam materials (polyurethane foam, latex rubber foam, synthetic foam) using the transient plane heat source method. Thermal conductivity measurements were taken for each foam material at different concentrations (obtained by compressing the foam to different thicknesses). The results showed that increasing the concentration of the material (decreasing porosity) led to an increase in the effective thermal conductivity, as compressing the foam evacuated more of the low conductivity air pockets within the material.
Heat transfer in sound assisted fluidized bed of fine powders a revieweSAT Journals
Abstract Nanoparticles have a rare quality of very small size and a large surface area per unit mass. These are most advantageously used
in many applications with their fluidization process. In such particles, for better fluidization process together with the
conventional gas fluidization technique some additional forces were studied by many authors. One of them is application of sound
waves. The presence of sound waves causes the decrease in the characteristic minimum fluidization velocity with increase in the
heat transfer rate from heating element to very small sized particles of fluidized bed. The brief information about nano powders,
fluidized bed and sound assisted fluidization process are given in the present article. Similarly, the heat transfer phenomenon in
fluidized bed, the effect of sound field on fluidization of powder in presence of sound field, the measurement techniques in
fluidized bed and design methods of heat transfer in fluidized bed are also presented.
Keyword: Nano Powders, Sound Field, Fluidization, Heat Transfer.
This document summarizes research into the compressive strength of geopolymer mortar made with ground granulated blast furnace slag (GGBFS) and fly ash activated by a 14 molar sodium hydroxide and sodium silicate solution. Cubes of geopolymer mortar were produced with different percentages of GGBFS and tested for compressive strength at ages of 1, 3, and 7 days. The results showed that compressive strength increased with GGBFS percentage and age. The maximum 7-day strength of 32.67 MPa was achieved with 80% GGBFS and a fluid-to-binder ratio of 0.45. Below this ratio strength decreased, indicating 0.45 is the optimum
Measurement of devolatilization time and transient shrinkage of a cylindIAEME Publication
This document summarizes an experimental study on the devolatilization of cylindrical wood particles in a bubbling fluidized bed combustor. Experiments were conducted to measure the devolatilization time and transient shrinkage of wood particles of varying sizes (10-30mm diameter) under different operating conditions, including bed temperature (750-950°C), inert bed material size (375-550μm), and fluidization velocity (5-10umf). Devolatilization time was found to be most influenced by initial wood particle size and bed temperature. Longitudinal shrinkage began after 50% conversion while radial shrinkage occurred from the start of devolatilization. Fluidization velocity and
This document evaluates different methods for determining the moisture content in wood and recommends the best method. It summarizes the process undertaken to establish a calibration system for moisture content meters at the National Institute for Standards in Egypt. Oven-drying wood samples was used as the standard method to calibrate two types of electric moisture meters: conductance and capacitance meters. Samples of various wood types were conditioned at different relative humidities and their moisture contents were measured using the meters and oven-drying for comparison. The calibration system aims to reduce errors and uncertainties in moisture content measurements.
The document presents results from an experimental study on the effects of elevated temperature and aggressive chemical environments on the compressive strength of M30 grade concrete. Concrete cubes were tested at temperatures from 200°C to 1000°C and exposed to sodium sulfate, sulfuric acid, and sodium chloride solutions for 30 and 60 days. Testing showed that compressive strength decreased with increasing temperature and exposure time, with rapid decreases above 400°C. Sulfuric acid exposure led to gypsum crystal deposition on cube surfaces.
Annealing Response of Aluminum Alloy AA6014 Processed By Severe Plastic Defor...IRJESJOURNAL
Abstract: In this paper the study of micro structural stability during annealing with respect to time of conventionally grains (CG) and ultrafine-grained (UFG) of Aluminum AA6014 i s carried out. It has been observed that, the effect of the second phase magnesium-silicon particles in the CG and UFG AA6014 samples leads to a rapid hardness which increases from 40HV10 to 70HV10 within 7 days. Artificial aging shows that the material hardness even increased after 20 hours of annealing at 180°C. In total 30 hours of annealing, the hardness arrives at its maximum and then reduces due to the formation of Mg2Si precipitates, which rise in size and change their coherency. The precipitates cannot efficiently pin the dislocations and act as barriers to the dislocation motion which indicate an overall decrease in the hardness. It also has been found that the ultrafinegrained AA6014 alloy loses its thermal stability at approximately 200°C and recrystallized at 300°C. Thermal stability is strongly dependent on the material purity, second phase particles and/or oxide particles which may break up during rolling and lead to some dispersion strengthening.
The document presents empirical correlations found through curve fitting to define pyrolysis properties of biomass fuels, including char yield, char composition, tar yield, heating values, and heat of devolatilization. Curve fitting was performed using least squares regression on experimental data from various literature sources on properties of biomass samples pyrolyzed from 573-1173 K. The correlations developed provide general equations to estimate selected biomass pyrolysis properties based on temperature, heating value, and ash content of the biomass.
Experimental Analysis of a Producer Gas Generated by a Chir Pine Needle (Leaf...IJERA Editor
This document summarizes an experimental study on the gasification of chir pine needles in a downdraft biomass gasifier. The study varied the air flow rate from 7-14 m3/h and moisture content from 4-12% to analyze their effects. Key findings include: biomass consumption rate increased with higher air flow rates but decreased with more moisture; the gas composition - specifically levels of hydrogen, carbon monoxide, and carbon dioxide - varied with the equivalence ratio of air to biomass. The study evaluated the gasifier performance through gas composition analysis, calorific value measurements, and a mass balance analysis showing average 87.9% closure.
The document investigates how catalyst amount, reaction temperature, and methanol/oil molar ratio affect the yield of soybean oil transesterification assisted by ultrasonic mixing and closed microwave irradiation. The optimal levels were found to be 1.0 wt% catalyst, 333 K temperature, and a 6:1 molar ratio, achieving a 97.49% yield. Statistical analysis confirmed all three factors significantly impacted the yield.
This document summarizes research on optimizing conditions for popping amaranth seeds. Experiments were conducted using a fluidized bed system to examine how varying the gas temperature, flow rate, and feed speed affected the seeds' volume expansion ratio and yield. Optimal popping occurred at gas temperatures between 230-290°C, with higher temperatures causing browning. A continuous processing prototype was also developed based on the experimental results.
The document summarizes an experiment that investigated the effect of austenitizing temperature and holding time on grain size and hardness in 4140 steel. Samples were heat treated at 900°C, 1000°C, and 1100°C for 1, 4, and 9 hours, followed by water quenching. Testing found that grain size increased and hardness decreased with higher temperature and longer time, consistent with standard grain growth models. Activation energy calculations found grain growth was driven by carbon diffusion in austenite. Overall, the study demonstrated that austenitizing conditions significantly influence prior austenite grain size and resultant hardness in 4140 steel.
This document summarizes a research paper that proposes a modified March test algorithm for high-speed testing of SRAM using a built-in self-test (BIST) architecture. The BIST architecture includes a test controller, pattern generator, input multiplexer, and comparator. It aims to detect various RAM fault models including stuck-at faults, coupling faults, transition faults, and address decoder open faults. An improved version of the March test algorithm is implemented using microcoded BIST techniques for flexibility in applying test patterns.
1) The document presents a control strategy for a grid-interfacing inverter connected to renewable energy sources to improve power quality at the distribution level grid connection point.
2) By controlling the inverter, it can act as both a power converter to inject renewable power into the grid and as an active power filter to compensate for current unbalance, load harmonics, reactive power demand, and neutral current without additional hardware costs.
3) The control strategy aims to maximize utilization of the inverter rating and allows the inverter and nonlinear/unbalanced load at the point of common coupling to appear as a balanced linear load to the grid, maintaining power quality standards.
The document proposes applying cellular manufacturing concepts to improve operations at an automobile workshop. The workshop currently faces long lead times and processing times for vehicle repairs. Mechanics are individually responsible for completing all repair tasks on assigned vehicles. This causes inefficient resource use, quality issues, and fatigue. The authors propose forming virtual cells grouping mechanics and similar repair tasks. Each cell would focus only on assigned repair tasks, allowing simultaneous work and reducing lead times. Simulation shows the proposed method halves lead time compared to the current approach. Benefits include improved quality, supervision, and resource utilization while also increasing repair rates and reducing vehicle downtime.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Cost Effective Experimental Setup for Gas Sensing Applicationsiosrjce
IOSR Journal of Applied Chemistry (IOSR-JAC) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of applied chemistry and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in Chemical Science. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Investigation on the activating effect of na2 co3 and naoh on slageSAT Publishing House
This document investigates the activating effect of sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) on the workability and compressive strength of alkali-activated slag materials. Heat release experiments show that slag activated with Na2CO3 reacts much slower than slag activated with NaOH, with the main reaction occurring around 40 hours after mixing compared to 30 minutes for NaOH. Testing of workability and 7-day compressive strength was done with different alkali dosages and water-to-binder ratios. In general, Na2CO3 provided higher fluidity and strength compared to NaOH under the same conditions.
Effect of water temperature on the mechanical properties of water quenched me...Alexander Decker
This document summarizes a study on the effect of water temperature on the mechanical properties of medium carbon steel samples quenched in water. Two steel samples with carbon contents of 0.33% and 0.42% were heated to 900°C and quenched in water ranging from 35°C to 95°C. Results showed hardness was reduced by over 18% and impact strength improved by over 50% at higher water temperatures, as the hard martensite structure was replaced with tempered martensite. Maximum hardness occurred at a water temperature of 65°C while maximum impact strength and tensile properties occurred at 95°C. The study concluded water quenching at higher temperatures can improve steel toughness with only slight
This document summarizes a standard test method for measuring the thermal transmission properties of thermally conductive electrical insulation materials. It describes measuring a material's thermal impedance using a test setup with two parallel isothermal surfaces that impose a temperature gradient on a test specimen in between. Measurements of the surface temperatures and heat flow rate are used to calculate the specimen's thermal impedance and apparent thermal conductivity. The test method can be used to evaluate liquids, gels, rubbers, ceramics, metals and some plastics. Adjusting the clamping pressure and applying thermal grease can help account for interfacial thermal resistance between the specimen and test surfaces.
In the recent research activities, the nanofluids have involved a great deal
attention since their superior report in thermal performance and many other
applications. Now a days cooling process is a great challenge in most of the chemical
process, Nuclear reactor, automobile radiator, micro electronics systems. To meet out
this, a novel coolant (Nano fluids) was developed by choi.S.U.S 1995 at Argonne
National lab. USA. In continuation to his work, water based alumina Nano fluids was
prepared and applied in shell and tube heat exchanger to analyze the heat transfer
rate. The same analysis is discussed with conventional base fluid of water and
alumina nanofluid also this presents the characterization of Alumina Nano particle by
means of XRD and SEM.
Investigation on effective thermal conductivity of foams using transient plan...eSAT Publishing House
The document describes an experimental setup used to determine the effective thermal conductivity of various foam materials (polyurethane foam, latex rubber foam, synthetic foam) using the transient plane heat source method. Thermal conductivity measurements were taken for each foam material at different concentrations (obtained by compressing the foam to different thicknesses). The results showed that increasing the concentration of the material (decreasing porosity) led to an increase in the effective thermal conductivity, as compressing the foam evacuated more of the low conductivity air pockets within the material.
Heat transfer in sound assisted fluidized bed of fine powders a revieweSAT Journals
Abstract Nanoparticles have a rare quality of very small size and a large surface area per unit mass. These are most advantageously used
in many applications with their fluidization process. In such particles, for better fluidization process together with the
conventional gas fluidization technique some additional forces were studied by many authors. One of them is application of sound
waves. The presence of sound waves causes the decrease in the characteristic minimum fluidization velocity with increase in the
heat transfer rate from heating element to very small sized particles of fluidized bed. The brief information about nano powders,
fluidized bed and sound assisted fluidization process are given in the present article. Similarly, the heat transfer phenomenon in
fluidized bed, the effect of sound field on fluidization of powder in presence of sound field, the measurement techniques in
fluidized bed and design methods of heat transfer in fluidized bed are also presented.
Keyword: Nano Powders, Sound Field, Fluidization, Heat Transfer.
This document summarizes research into the compressive strength of geopolymer mortar made with ground granulated blast furnace slag (GGBFS) and fly ash activated by a 14 molar sodium hydroxide and sodium silicate solution. Cubes of geopolymer mortar were produced with different percentages of GGBFS and tested for compressive strength at ages of 1, 3, and 7 days. The results showed that compressive strength increased with GGBFS percentage and age. The maximum 7-day strength of 32.67 MPa was achieved with 80% GGBFS and a fluid-to-binder ratio of 0.45. Below this ratio strength decreased, indicating 0.45 is the optimum
Measurement of devolatilization time and transient shrinkage of a cylindIAEME Publication
This document summarizes an experimental study on the devolatilization of cylindrical wood particles in a bubbling fluidized bed combustor. Experiments were conducted to measure the devolatilization time and transient shrinkage of wood particles of varying sizes (10-30mm diameter) under different operating conditions, including bed temperature (750-950°C), inert bed material size (375-550μm), and fluidization velocity (5-10umf). Devolatilization time was found to be most influenced by initial wood particle size and bed temperature. Longitudinal shrinkage began after 50% conversion while radial shrinkage occurred from the start of devolatilization. Fluidization velocity and
This document evaluates different methods for determining the moisture content in wood and recommends the best method. It summarizes the process undertaken to establish a calibration system for moisture content meters at the National Institute for Standards in Egypt. Oven-drying wood samples was used as the standard method to calibrate two types of electric moisture meters: conductance and capacitance meters. Samples of various wood types were conditioned at different relative humidities and their moisture contents were measured using the meters and oven-drying for comparison. The calibration system aims to reduce errors and uncertainties in moisture content measurements.
The document presents results from an experimental study on the effects of elevated temperature and aggressive chemical environments on the compressive strength of M30 grade concrete. Concrete cubes were tested at temperatures from 200°C to 1000°C and exposed to sodium sulfate, sulfuric acid, and sodium chloride solutions for 30 and 60 days. Testing showed that compressive strength decreased with increasing temperature and exposure time, with rapid decreases above 400°C. Sulfuric acid exposure led to gypsum crystal deposition on cube surfaces.
Annealing Response of Aluminum Alloy AA6014 Processed By Severe Plastic Defor...IRJESJOURNAL
Abstract: In this paper the study of micro structural stability during annealing with respect to time of conventionally grains (CG) and ultrafine-grained (UFG) of Aluminum AA6014 i s carried out. It has been observed that, the effect of the second phase magnesium-silicon particles in the CG and UFG AA6014 samples leads to a rapid hardness which increases from 40HV10 to 70HV10 within 7 days. Artificial aging shows that the material hardness even increased after 20 hours of annealing at 180°C. In total 30 hours of annealing, the hardness arrives at its maximum and then reduces due to the formation of Mg2Si precipitates, which rise in size and change their coherency. The precipitates cannot efficiently pin the dislocations and act as barriers to the dislocation motion which indicate an overall decrease in the hardness. It also has been found that the ultrafinegrained AA6014 alloy loses its thermal stability at approximately 200°C and recrystallized at 300°C. Thermal stability is strongly dependent on the material purity, second phase particles and/or oxide particles which may break up during rolling and lead to some dispersion strengthening.
The document presents empirical correlations found through curve fitting to define pyrolysis properties of biomass fuels, including char yield, char composition, tar yield, heating values, and heat of devolatilization. Curve fitting was performed using least squares regression on experimental data from various literature sources on properties of biomass samples pyrolyzed from 573-1173 K. The correlations developed provide general equations to estimate selected biomass pyrolysis properties based on temperature, heating value, and ash content of the biomass.
Experimental Analysis of a Producer Gas Generated by a Chir Pine Needle (Leaf...IJERA Editor
This document summarizes an experimental study on the gasification of chir pine needles in a downdraft biomass gasifier. The study varied the air flow rate from 7-14 m3/h and moisture content from 4-12% to analyze their effects. Key findings include: biomass consumption rate increased with higher air flow rates but decreased with more moisture; the gas composition - specifically levels of hydrogen, carbon monoxide, and carbon dioxide - varied with the equivalence ratio of air to biomass. The study evaluated the gasifier performance through gas composition analysis, calorific value measurements, and a mass balance analysis showing average 87.9% closure.
The document investigates how catalyst amount, reaction temperature, and methanol/oil molar ratio affect the yield of soybean oil transesterification assisted by ultrasonic mixing and closed microwave irradiation. The optimal levels were found to be 1.0 wt% catalyst, 333 K temperature, and a 6:1 molar ratio, achieving a 97.49% yield. Statistical analysis confirmed all three factors significantly impacted the yield.
This document summarizes research on optimizing conditions for popping amaranth seeds. Experiments were conducted using a fluidized bed system to examine how varying the gas temperature, flow rate, and feed speed affected the seeds' volume expansion ratio and yield. Optimal popping occurred at gas temperatures between 230-290°C, with higher temperatures causing browning. A continuous processing prototype was also developed based on the experimental results.
The document summarizes an experiment that investigated the effect of austenitizing temperature and holding time on grain size and hardness in 4140 steel. Samples were heat treated at 900°C, 1000°C, and 1100°C for 1, 4, and 9 hours, followed by water quenching. Testing found that grain size increased and hardness decreased with higher temperature and longer time, consistent with standard grain growth models. Activation energy calculations found grain growth was driven by carbon diffusion in austenite. Overall, the study demonstrated that austenitizing conditions significantly influence prior austenite grain size and resultant hardness in 4140 steel.
This document summarizes a research paper that proposes a modified March test algorithm for high-speed testing of SRAM using a built-in self-test (BIST) architecture. The BIST architecture includes a test controller, pattern generator, input multiplexer, and comparator. It aims to detect various RAM fault models including stuck-at faults, coupling faults, transition faults, and address decoder open faults. An improved version of the March test algorithm is implemented using microcoded BIST techniques for flexibility in applying test patterns.
1) The document presents a control strategy for a grid-interfacing inverter connected to renewable energy sources to improve power quality at the distribution level grid connection point.
2) By controlling the inverter, it can act as both a power converter to inject renewable power into the grid and as an active power filter to compensate for current unbalance, load harmonics, reactive power demand, and neutral current without additional hardware costs.
3) The control strategy aims to maximize utilization of the inverter rating and allows the inverter and nonlinear/unbalanced load at the point of common coupling to appear as a balanced linear load to the grid, maintaining power quality standards.
The document proposes applying cellular manufacturing concepts to improve operations at an automobile workshop. The workshop currently faces long lead times and processing times for vehicle repairs. Mechanics are individually responsible for completing all repair tasks on assigned vehicles. This causes inefficient resource use, quality issues, and fatigue. The authors propose forming virtual cells grouping mechanics and similar repair tasks. Each cell would focus only on assigned repair tasks, allowing simultaneous work and reducing lead times. Simulation shows the proposed method halves lead time compared to the current approach. Benefits include improved quality, supervision, and resource utilization while also increasing repair rates and reducing vehicle downtime.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document describes the design and implementation of a MAC transmitter for transmitting UDP packets using finite state machine and Verilog coding techniques. The MAC transmitter converts 32-bit data to 4-bit data for transmission. The UDP packet data is used as the MAC frame data. The design includes modules for frame assembly, CRC generation, and a transmitter that monitors collisions and performs back-off. Simulation results show the transmitter transmits preambles, starts/end frames, CRC correctly and performs back-off when collisions occur reliably using Verilog coding.
This document presents a new modified F-expansion method to obtain traveling wave solutions of the Benjamin-Bona-Mahony (BBM) equation and modified BBM equation. The method is applied to these nonlinear partial differential equations. Specifically:
1) The traveling wave solutions of the BBM equation are considered by substituting a transformation.
2) The solution is assumed to have the form of a polynomial in F(ξ) and its derivatives, where F(ξ) satisfies a Riccati equation.
3) Three explicit solutions for the BBM equation are obtained in terms of hyperbolic and trigonometric functions.
This document analyzes the stress on a robot hand using finite element analysis software ANSYS. The robot hand CAD model was imported into ANSYS and meshed. A static structural analysis was performed considering gravitational and inertial forces. The maximum von Mises stress was found to be 0.89649 MPa. The maximum torque of 1.5 N-mm acted on the thumb joint due to its weight and deformation requirements, while other finger joints experienced between 0.45-0.6 N-mm of torque.
Una herida es una falta de continuidad de la piel causada por un golpe, corte u otra lesión. Existen diferentes tipos de heridas que requieren distintos niveles de atención, desde curar una herida leve en casa hasta buscar atención médica inmediata para heridas graves.
El juego Mars Attack permite al jugador moverse por la pantalla usando un joystick y destruir enemigos mediante colisiones, mientras evita ser destruido a su vez.
Este documento describe un proyecto para crear nuevos canales de comunicación social para una asociación a través de redes sociales como un blog, Twitter y Flickr. El objetivo era mejorar la comunicación, unificar la imagen y aumentar el impacto mediante la integración de estas plataformas y la formación de su uso. Se estableció una estrategia y se implementaron pasos como crear cuentas, conectar los servicios y ofrecer talleres a empresas asociadas.
Mohammed Asaduzzaman: Mitigation in Bangladesh's National Climate Change Action Plan and priorities for research (presentation from Mitigation session at CCAFS Science Workshop, December 2010)
El documento describe diferentes usos educativos de las herramientas de un campus virtual como foros, preguntas frecuentes, cajón de desperdicios y tutorías. Como ejemplos, menciona utilizar un foro para conocer los intereses de los estudiantes sobre historia griega, plantear preguntas personales en ética a través de preguntas frecuentes, compartir análisis literarios en el cajón de desperdicios, y abordar bullying de forma privada a través de tutorías.
O documento descreve o método de análise nodal para solução de circuitos elétricos. O método envolve (1) escolher um nó de referência, (2) aplicar a lei de Kirchhoff nos demais nós, (3) considerar as relações tensão-corrente para substituir as correntes por tensões, (4) resolver o sistema de equações resultante para obter as tensões nos nós. O documento ilustra o método com um exemplo de três nós.
Relatório da CPMI da Violência Contra a MulherPaulo Veras
- A Comissão Parlamentar Mista de Inquérito foi criada para investigar a situação da violência contra a mulher no Brasil e apurar denúncias de omissão por parte do poder público na proteção de mulheres em situação de violência.
- O relatório apresenta a composição inicial e final da Comissão, com a indicação dos membros titulares e suplentes do Senado Federal e da Câmara dos Deputados para cada partido ou bloco.
- A Comissão teve seu prazo de duração prorrogado duas vezes, encerrando seus trabalhos em agosto de 2013.
Este documento presenta una introducción a la auditoría de sistemas. Explica que la auditoría evalúa la eficiencia y eficacia de los sistemas tecnológicos de una organización para administrar riesgos. Define la auditoría como una revisión periódica e intelectual de registros y resultados para medir el desempeño de una empresa. Luego describe los objetivos generales de una auditoría de sistemas y los diferentes alcances sobre los que puede enfocarse, como la administración del departamento de sistemas, control de actividades, seguridad
O documento discute conceitos de colisão no Unity 3D, incluindo tipos de colisores, componentes de colisão, tratamento de colisão com scripts e ray casting. Também aborda triggers e como ignorar colisões entre objetos específicos.
El documento habla sobre la tecnología y su definición, objetivo y consecuencias. Define la tecnología como un conjunto de saberes que permite crear objetos y modificar el medioambiente. Su objetivo es satisfacer las necesidades humanas pero puede tener consecuencias negativas como destruir el medioambiente y contaminar. Luego menciona algunas nuevas tecnologías como chips cerebrales, camisetas con Wi-Fi y sistemas de educación en línea.
Abstract Fresh spinach leaves with 50g weight were taken from the market and 9.86 moisture content on dry basis were dried in a microwave oven using four different microwave power levels ranging between 90 and 350 W, until the moisture content fell down to 0.1 on dry basis. The drying processes were completed between 570 and 1350s depending on the microwave power level. Moisture ratio and drying rate were calculated. In this study the measured values of moisture ratio were compared with predicted values obtained from Newton, Henderson and Pabis, Midilli et al and pages thin layer drying semi empirical equations. On detailed study of the four model equations, Midilli et al. equation was found to be the best fit for the drying of spinach leaves by spinach leaves by using microwave oven. The fitness of these models was evaluated by using the reduced chi-square, root mean square error and modeling efficiency. The specific energy consumption to evaporate a unit mass of water from the product was also determined. Keywords: Spinach Leaves, Moisture Content, Moisture Ratio, Drying rate and Micro wave.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...drboon
The aim of this paper is to report tomato slice moisture diffusivity data determined and activation energy from experimental drying kinetics. The thin-layer drying experiments were carried out under five air temperatures of 40, 50, 60, 70 and 80ºC, two air velocity 1.5, and 2 m/s and three level of relative humidity 20, 40 and 60%. It was observed that drying took place in the falling rate period. Moisture transfer from tomato slice was described by applying the Fick’s diffusion model. The effective diffusivity values changed from 9.9119×10^-10 to 6.4037×10^-9 m^2/s for the range of temperatures considered. An Arrhenius relation with an activation energy value of 33.3299 to 43.2287 kJ/mol and the diffusivity constant value of 1.7695×10^-4 to 3.09156×10^-2 m^2/s were obtained which shows the effect of drying air temperature, air velocity and relative humidity on the diffusivity.
This document summarizes a study on the thermal kinetics of thin layer drying of Indian gooseberry (aonla) flakes. Experiments were conducted to dry aonla flakes at air velocities of 0.48m/s, temperatures ranging from 40-75°C, and relative humidity of 35%. Moisture content was measured periodically to calculate moisture ratio. Drying coefficients were determined using the half life time method and linear regression analysis. The experimental data was best fitted by the Modified Page model with reasonably low root mean square errors between 0.0094-0.0382 and high efficiencies between 0.9598-0.9985. Correlations for the drying coefficient and shape factor in terms of temperature were also
THERMAL KINETICS OF THIN LAYER DRYING OF INDIAN GOOGEBERRY OR ANOLA FLAKS (PH...IAEME Publication
The aonla (Phyllanthus emblica), a fruit rich in vitamin-C, has high medicinal importance in human life. Drying of aonla in the form of flakes and powder is one of the widely used methods of its preservation. Thermal kinetics during drying a hygroscopic material in thin layer, the moisture ratio is calculated by the Half Life Time Method. The experiment was conducted at an average velocity of 0.48m/s, relative humidity 35% and temperature in the range from 40 to 750C.
This document presents a study on developing a mathematical model for drying spinach leaves in a universal hot air oven. Drying experiments were conducted using air velocities of 2.2 m/s and temperatures of 55, 65, and 75°C under different pretreatment and loading density conditions. The drying rate increased with increased temperature and decreased over time. Pretreatment and loading density had an insignificant effect on drying rate. Experimental drying data was applied to four moisture ratio models, and nonlinear regression analysis was used to relate model parameters to drying conditions. The Page model was found to best describe spinach drying behavior based on having the lowest standard error and highest coefficient of determination compared to other models.
Effect of Packaging materials on Quality Parameters of GarlicIJERA Editor
The document discusses a study on the effect of different packaging materials on the quality parameters of dried garlic flakes stored for 3 months. Garlic was dried using convective-cum-microwave and fluidized-cum-microwave hybrid drying techniques and packaged in high density polyethylene, low density polyethylene, and laminated aluminum foil. Samples were tested for rehydration ratio, color, weight loss, and acceptability over storage time. Aluminum packaging best maintained quality over 3 months of storage for both drying techniques. Fluidized bed-cum-microwave dried garlic flakes packaged in aluminum showed the best storage stability and quality.
Thin Layer Drying Characteristics of Basil (Ocimum Gratissimum L.) LeavesIRJET Journal
This document presents research on the thin layer drying characteristics of basil (Ocimum gratissimum L.) leaves. Fresh basil leaves were dried in a tray dryer at temperatures of 45, 50, and 55°C and loading densities of 2.5, 3.0, and 3.5 kg/m2. Drying time decreased with increasing temperature and decreasing loading density. The Midilli model best described the drying behavior with the highest R2 and lowest RMSE. Effective moisture diffusivity values ranged from 5.0 × 10-9 to 3.64 × 10-7 m2/s. Activation energy values ranged from 44.98 to 42.63 kJ/mol. Nutritional analysis and sensory evaluation were
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Statistical Modelling of Drying Characteristics of Unripe Plantain (Musa Para...Dr. Amarjeet Singh
This work is designed to carry out the statistical modelling of the drying characteristics of unripe plantain (Musa paradisiaca) slices and to study the effect of drying temperature and slice thickness on drying characteristics. The test samples were dried in a laboratory scale oven dryer at varying temperatures of 700C, 800C and 900C, and different slice thicknesses of 2mm, 3mm and 4mm.The result obtained indicated that drying temperature and slice thickness had significant effect on drying rate and hence moisture profile. The moisture ratio – drying time data obtained were fitted to ten thin layer drying models. The fit quality obtained with each model was evaluated using statistical tests namely; coefficient of determination (R2), root mean square error (RMSE), reduced chi-square (X2), and standard error of estimate (SEE). Although most of the models fitted quite well to the experimental data, Page and Modified Page models showed the highest average R2 and the lowest average RMSE, X2 and SEE values. Page and modified Page models were selected and found suitable to represent the drying characteristics of unripe plantain slices and predict drying times.
Kinetics and Mathematical Modeling of Microwave Drying of Sri Lankan Black Pe...Agriculture Journal IJOEAR
The document describes research on modeling the microwave drying kinetics of Sri Lankan black pepper. Drying experiments were conducted at three microwave power levels and the data was fitted to seven thin layer drying models. The Midilli, Weibull, and Kaleta models provided the best fit to the experimental drying data based on statistical analysis. The drying rate and effective moisture diffusivity increased with increasing microwave power level. The results showed that black pepper drying occurs entirely within the falling rate period, indicating that moisture diffusion controls the drying rate.
Cold Plasma: A Novel Pretreatment Method for Drying Canola Seeds: Kinetics St...J. Agricultural Machinery
Accurate investigation of kinetics and development of high-precision seed drying models will help better studying the drying process by identifying effective parameters. Present study investigates the application of cold plasma (CP), as a pretreatment process, in air drying of canola seeds. This may bring about some complication into the drying kinetics investigation. Canola seeds with an initial moisture content of 27.5±1% (dry basis) were exposed to CP for 0, 15, 30, and 60 s prior to fluidization by air at temperatures of 40, 50 and 60 °C in a pilot scale fluidized bed heated by a solar panel. The results showed a decreasing trend in drying time from 40 to 60 oC. The shortest drying time corresponds to samples dried at 60 oC with no CP pretreatment. The longest period however occurred for samples dried at 40 oC with 60 s of CP pretreatment. The greatest effect of CP on reducing the drying time was observed at temperatures of 40 and 50 °C at the CP exposure time of 15 and 60 s, respectively. A reasonably accurate study of drying kinetics was accomplished using the superposition method. Accordingly, using experimental data, curves correspond to different drying conditions were plotted and in two steps these were shifted to a reference curve to acquire a final drying curve. The curve then was fitted to a second-order equation, and was validated using the experimental data. The correlation coefficients, mean square error and mean absolute error were 0.99, 0.03, and 0.023, respectively.
This document provides an overview of electrohydrodynamic (EHD) drying, a novel food drying technique. It begins with background on conventional drying methods and their limitations. EHD drying uses high voltage electric fields and corona discharge to generate an "electric wind" that enhances heat and mass transfer, enabling faster drying rates. Several studies applying EHD drying to foods like potatoes, rice, shrimp, and banana slices are summarized. Results show improved quality retention over conventional drying, with reduced shrinkage, better color and rehydration. EHD drying also uses less energy than conventional methods. However, further research is still needed to optimize the process and design equipment for commercialization.
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...RSIS International
Moisture removal from crops and other food items is
one of the ways to preserve them for longer duration. Previously,
drying openly in sun was used to reduce moisture content. But it
had some disadvantages like contamination due to dirt and other
unwanted elements as well as attack by rodents and birds.
Drying in covered close space with vents would be helpful in
overcoming these problems. Solar greenhouse dryers are the
close conduits in which crops can be dried without negatively
affecting the nutrition value. The factors affecting the crop
drying are solar radiation, climatic conditions, material of which
the dryer is made of and shape of the dryer. A lot of
experimental investigations have been done to improve the
drying rate. With the advances in computational power and
numerical techniques, Computational Fluid Dynamics (CFD) has
emerged as a powerful tool to optimize any design. In the present
study, simulations have been done on greenhouse dryer with
modifications to identify the temperature distribution with
variation in wind velocity. Different radiation levels have also
been found out at different locations in the dryer. The model of
the dryer has been created in CREO 5.0 and analysis has been
performed using ANSYS 14.0. The simulation has been done for
both forced and natural convection. Obtained results have been
validated with the experimental work done by previous works.
Better drying rate has been obtained for forced circulation as
compared to natural convection which is in agreement with the
available experimental results.
Mathematical Modeling of Thin Layer Drying Kinetics of Tomato Influence of Ai...drboon
Thin-layer drying kinetics of Tomato was experimentally investigated in a pilot scale convective dryer. Experiments were performed at air temperatures of 40, 60, and 80ºC and at three relative humidity of 20%, 40% and 60% and constant air velocity of 2 m/s. In order to select a suitable form of the drying curve, 9 different thin layer drying models were fitted to experimental data. The high values of coefficient of determination and the low values of reduced sum square errors and root mean square error indicated that the Midilli et al. model could satisfactorily illustrate the drying curve of tomato. the Midilli et al. model had the highest value of R2 (0.9997), the lowest SSE (0.22662) and RMSE (0.0040912) for relative humidity of 20% and air velocity of 2 m/s. the Midilli et al. model had the highest value of R2 (0.99946), the lowest SSE (0.46702) and RMSE (0.0051192) for relative humidity of 40% and air velocity of 2 m/s. the Midilli et al. model had the highest value of R2 (0.99952), the lowest SSE (0.438982) and RMSE (0.0050188) for relative humidity of 60% and air velocity of 2 m/s. The Midilli et al. model was found to satisfactorily describe the drying behavior of tomato.
This document summarizes a study that modeled the thin-layer drying behavior of eggplant slices in a convective-type cyclone dryer. Drying experiments were conducted at air temperatures of 55, 65, and 75°C and velocities of 1 and 1.5 m/s. The Page model provided the best fit for the drying curves with a correlation coefficient of 0.9999. Air temperature had a significant effect on drying rate, while air velocity had a smaller effect. All drying occurred in the falling rate period with no constant rate drying period. The study aims to determine the effects of temperature and velocity on drying kinetics and select the best mathematical model to describe the drying curves.
The performance of a fluidized bed dryer integrated biomass furnace with air preheater (FBD with APH) and a fluidized bed dryer integrated biomass furnace without air preheater (FBD without APH) for drying of paddy have been evaluated. The FBD with APH and FBD without APH decreased the moisture of paddy from 24% (wet basis) to 14% (wet basis) within 43 and 47 minutes with average temperatures and relative humidities of 59.58 oC and 59.14oC, and 18.81% and 18.68%, respectively. The drying rate of paddy varied in the range of 0.11 kg/min-0.32 kg/min and 0.10 kg/min- 0.30 kg/min for FBD with APH and FBD without APH, with average values of 0.18kg/min and 0.17kg/min, respectively. The minimum, maximum, and average value specific moisture evaporation rate (SMER) was 0.20 kg/kWh, 0.57 kg/kWh, and 0.31 kg/kWh, respectively for FBD with APH, as well as 0.149 kg/kWh, 0.448 kg/kWh, and 0.252 kg/kWh, respectively, for FBD without APH. The specific energy consumption (SEC), the specific electrical energy consumption (SEEC), and the specific thermal energy consumption (STEC) were varied from 1.749 kWh/kg to 5.076 kWh/kg, 0.090 kWh/kg to 2.872 kWh/kg, and 0.760 kWh/kg to 2.204 kWh/kg, with average values of 3.528 kWh/kg, 1.96 kWh/kg, and 1.532 kWh/kg, respectively for FBD with APH, as well as from 2.234 kWh/kg to 6.702 kWh/kg, 1.056 kWh/kg to 3.167 kWh/kg, and 1.179 kWh/kg to 3.536 kWh/kg, with average values of 4.391 kWh/kg, 2.075 kWh/kg, and 2.316 kWh/kg, respectively, for FBD without APH. The thermal efficiencies of the FBD with APH and FBD without APH were varied between 12.4% and 37.93%, and 9.78% and 29.82%, resvectively, with average values of 20.78% and 16.61%. The thermal efficiency of FBD with APH was higher compared to FBD without APH.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes an experiment on modeling the drying behavior of green beans. Green beans were dried in a hot air dryer at 50°C until their moisture content decreased from 90.53% to 14%. Drying rate curves were obtained and fitted to the Henderson-Pabis, Lewis, and Page models. The Page model provided the best fit based on its lower chi-square and root mean square error values. Effective diffusivity was calculated as 2.641*10-9 m2/s using the Page model results. In conclusion, the Page model best represented the drying characteristics of green beans in this experiment.
The heating pattern of the microwave dehydrator for treating petroleum crude ...eSAT Publishing House
This document summarizes a study that investigated the heating patterns of different petroleum crude oils and water samples when exposed to microwave radiation in a modified domestic microwave oven. The key findings were:
1) Water reached the highest temperatures initially, followed by oils from the UAE and Saudi Arabia. After 110 seconds, a Kuwait crude oil sample surpassed the others in temperature.
2) Water absorbed microwave energy at the highest rate, followed by oils from Kuwait, Saudi Arabia, and UAE.
3) Water had the highest dielectric loss and lowest wavelength, while oil samples had lower and consistent dielectric properties and a longer wavelength.
4) Different crude oils exhibited distinct heating profiles when exposed to microwave
The heating pattern of the microwave dehydrator for treating petroleum crude ...
At24301310
1. A.K.Upadhyaya, Bhupendra Gupta, Sanjeev Garg, Mohan Singh, Mukesh Pandey/
International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Study of Moisture Depletion Pattern of Spinach in Hot Air Oven
A.K.Upadhyaya 1, Bhupendra Gupta 2, Sanjeev Garg 3, Mohan Singh4, Mukesh Pandey5
1
Student of ME, Mechanical Engineering (Heat power), JEC Jabalpur,
2
Faculty of Mechanical Engineering Department, JEC Jabalpur,
3,4
Faculty of Post Harvest Process and Food Engineering, JNKVV Jabalpur,
5
Dean (Academics) and Professor, Department of Energy, RGPV, Bhopal
ABSTRACT
Now a day it is evident from previous works on spinach, a cabinet dryer with low Relative Humidity
drying of food, fruits and vegetables by different (RH), constant airflow and high temperatures has
scholars are that there are no as such exact theoretical selected. Blanching has done to improve final product
laws or theoretical equations have developed. That can quality and reduce process cost. It has observed that a
explain explicitly or implicitly the drying behavior of temperature range in vicinity of 50 oC to 70 oC was
these biodegradable substances because there are many suitable for drying of spinach. Increase in air
variables in these products. The major variables are temperature significantly reduces the drying time. The
biological conditions i.e. geographical condition as well air velocity during drying has taken 2.2 m/s that is
as atmospheric condition. That varies from place to sufficient to keep relative humidity low inside the dryer.
place and time to time. Other variables are Relative In our curves, drying occurs majorly in falling rate of
Humidity (RH), Moisture Content, Drying medium drying.
Temperature, air or gas Flow velocity, Conduction,
Convection, Radiation and Mass transfer mechanism. 2. EXPERIMENTAL METHOD
Apart from these some other factors are liquid
diffusion such as (capillary flow, surface diffusion, 2.1. Materials
Hydrodynamics mechanics), vapor diffusion (Mutual Fresh spinach leaves procured from local market
diffusion, knudsen diffusion, effusion, slip flow, everyday prior to the experiment. They washed with tap
hydrodynamic flow, stepan diffusion, evaporation, water the moisture on the wet sample surface removed
poiseuille flow) etc. Still searches are going on and with filter paper .The average value of moisture content
nobody could assure that at any instance of time 93.41% (w.b.) which shows that spinach leaves can be
transfer of moisture has caused by above known group under highly perishable vegetables. Spinach
mechanism. Due to these difficulties, we can easily leaves were pre treated by blanching with distilled water.
conclude that for prediction about drying nature, we Treated sample were placed over filter paper (Wattman
need an experimental setup and results and each result filter paper .size 41 A) for 1 minute to absorb excess
are unique one. In present work, spinach for drying in water.
blanched and unblanched condition with loading
densities 3kg/m3& 3.5 kg/m3in a cabinet air dryer in 2.2. Experimental method
which drying nature validates the exponential model of Drying experiments performed in cabinet dryer (hot air
drying has selected. oven, tradevel scientific industries, least count 10C) and
installed in Department of Post Harvest Process and
Keywords: (Me) Equilibrium Moisture Content, Food Engineering, College of Agriculture Engineering
Moisture Content (MC), (MR) Moisture Ratio, Treated (JNKVV, JABALPUR). Sample were weighed in digital
(Blanched), Untreated (Unblanched) balance (METTLER, least count 0.001g )according to
the loading density of 3.0kg/m3and 3.5kg/m3 and placed
1. INTRODUCTION in a stainless steel mesh tray of size 0.0123m2 and
In this, spinach with 3kg/m3 & 3.5 kg/m3 0.0168 m2giving equivalent sample weight of 70g and
loading densities in blanched and unblanched condition 80g corresponding to different loading densities. Table 1
with temperature range 55 0C, 650C, and 750C, has shows the details of equipment used for the experiment.
selected. Drying characteristic of spinach mostly Figure 1, figure 2 and figure 3, shows the universal hot
controls by availability of moisture in it. For drying of air oven, sample of spinach, and dried product
respectively.
301 | P a g e
2. A.K.Upadhyaya, Bhupendra Gupta, Sanjeev Garg, Mohan Singh, Mukesh Pandey/
International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Table.1 Specification of experimental apparatus
Apparatus Specification Make
Balance electronic Capacity-210 g Mettler
Least Count:0.001g
Hot Air Oven Heater :1200 W Tradevel Scientific Industries.
Voltage :220-2300 V
Temperature :50-2500C
Least count :10C
Desiccator Diameter :150 and 300 mm Brosil
Petri dish Glass Brosil
Disposable Tarsons
Refrigerator 310 litre Kelvinator
Fig 2 Primary sample image of spinach
Fig 1 Universal hot air oven Fig 3 Dried stored sample of spinach
302 | P a g e
3. A.K.Upadhyaya, Bhupendra Gupta, Sanjeev Garg, Mohan Singh, Mukesh Pandey/
International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Method recommended by Ranganna (1986) was use for 3. RESULTS AND DISCUSSIONS
determination of moisture content and for all It was attempt to describe the drying process of
experiments; the initial moisture content taken to be spinach leaves by fitting the experimental data on
1418.37 %( d.b.).The sample of both blanched and selected exponential drying model for describing the
Unblanched were subjected to uniform air velocity 2.2 moisture depletion pattern of spinach. The suitability of
m/s at specified three level of temperature drying models was evaluated based on regression
(55oC,65oC,and 75 0C) and two level of loading density coefficient value (R2), and the value of MR moisture
(3.0 and 3.5 kg/m3) .The sample were dried for a ratio calculated by the help of equilibrium moisture
minimum of eight hours of drying. Weights of the content, which is calculated by the method developed
samples recorded after every hour during drying by Henderson and Perry (1976)
process. The dried samples cooled under laboratory
conditions after each drying experiments, and kept in
airtight jars. The experiments were triplicate and
average of the moisture ratio at each value used for Where, Mo and M are the moisture content (% db) at
drawing the drying curves. time (θ) equal to zero and at any time (θ). To validate
the experimental drying curves exponential
mathematical models used mentioned in table2.
Table.2 Model equations developed for drying process
S.No. Model Name Model Equation References
1 Page (1949) Page
2 Henderson and pabis (1969) Henderson and Pabis
3 Newton (1971) O’ Callaghan et al.
4 Modified Page(1973) Overhults et al.
5 Two Term (1980) Sharaf-Eldeen et al.
6 Midilli (2002) Midilli et al.
All these equations used the moisture ratio (MR) as dependent variable, which related the gradient of the sample
moisture content in real time with the initial moisture content and equilibrium moisture content. The experimental drying
data graphically analyzed. Variations of moisture content with time, variation in drying rate with drying time and
variation in moisture ratio with drying time in terms of reduction in moisture content were drawn. The experimental data
for drying of spinach leaves statistically and graphically analyzed with the help of spreadsheet (EXCEL) software
packages on personal computer. In first experiment, the following curves for spinach observed.
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Figure 4 Blanched sample at T= 55oC plotted between Moisture content & Time.
Figure 5 Unblanched samples at T= 55oC plotted between Moisture content & Time.
From above two figures Fig.4 and Fig.5 it is evident that moisture depletion pattern of spinach is nearly same for two
different loading densities at T=55oC.Nearly same data also observed for two loading densities at two other temperature
ranges i.e. at T=65 oC & T= 75oC those are given below.
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Figure 6 Blanched sample at T= 65oC plotted between Moisture content & Time.
Figure 7 Blanched sample at T= 75oC plotted between Moisture content & Time.
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
From figure 6 and 7, it is evident that total drying time considerably reduces with the increase in dry air temperature
from 55oC to 75 oC. The drying rate increases with increase in temperature and decreases with increase in time. For
analyzing the pretreatment on drying of spinach, following curves have plotted those mentioned in fig. (8-10).
Figure 8 Treated & Unblanched sample at T= 55oC plotted between Moisture content & Time.
Figure 9 Treated & Unblanched sample at T= 65oC plotted between Moisture content & Time.
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Figure 10 Treated & Unblanched sample at T= 75oC plotted between Moisture content & Time.
From above figure (8, 9, &10), it is evident that pretreatment i.e. blanching does not affect the drying rate and it is
preferable to do pretreatment in drying because it improves the drying quality of the spinach. Due to absence of a
constant rate period found during the experimental drying of spinach, which validates exponential model that describe
the phenomena of drying in falling rate period. The change of moisture ratio with time at different temperature of drying
for various experiments has shown in Fig (11-13).
Figure 11 Validation of exponential model for treated and untreated sample between moisture ratio and time at
temperature T=55 oC.
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8. A.K.Upadhyaya, Bhupendra Gupta, Sanjeev Garg, Mohan Singh, Mukesh Pandey/
International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Figure 12 Validation of exponential model for treated and untreated sample between moisture ratio and time at
temperature T=65 oC.
Figure 13 Validation of exponential model for treated and untreated sample between moisture ratio and time at
temperature T=75 oC
From above curves, it is evident that drying curve plotted between moisture ratio and time follows exponential law and
pretreatment has insignificant role in drying of spinach in terms of moisture ratio. At beginning of drying moisture ratio
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
is high i.e. one and at the span of time it decreases exponentially. To explain the effect of different temperatures with
treatment condition at different loading densities have plotted in fig (14 -17).
Figure 14 Untreated sample with loading densities 3kg/m3plotted between
Moisture ratio & time
Figure 15 Treated sample with loading densities 3kg/m 3plotted between
Moisture ratio & time
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10. A.K.Upadhyaya, Bhupendra Gupta, Sanjeev Garg, Mohan Singh, Mukesh Pandey/
International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
Figure 16 Untreated sample with loading densities 3.5kg/m3plotted between
Moisture ratio & time
Figure 17 Treated sample with loading densities 3.5kg/m 3plotted between
Moisture ratio & time
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International Journal of Engineering Research and Applications (IJERA)
ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 4, July-August 2012, pp.301-310
From above graph it is evident that treated and untreated 8. Bruin, S. and Luyben, K., 1980, in Mujumdar,
samples with two different loading densities follows A.S. (ed)(McGraw-Hill Co, US), pp.155– 215
exponential law better at higher temperature i.e. 75 oC & 9. C ¸ akmak, G. and Yıldız, C., 2009, Design of a
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Pretreatment had an insignificant role on the 13. Henderson, S.M. and Pabis, S., 1969, Grain
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