The energy consumption for space cooling is progressively increasing. Integrating renewable energ... more The energy consumption for space cooling is progressively increasing. Integrating renewable energy into space cooling systems is critical for reducing CO2 emissions from the building sector. The salt-based cooling system is an appealing alternative as it can be charged by solar energy. This system is based on the characteristic of endothermic salts, which generate a considerable cooling effect when dissolved in water. A screening test was performed in this work to evaluate the cooling performance of several endothermic salts. Furthermore, a laboratory-scale system was developed to demonstrate the endothermic salt-based thermal storage and cooling generation system. Temperature decreases up to 12.3 °C were observed in the system containing Potassium Chloride salt. The temperature drop was maintained after the system underwent a charging/discharging cycle; however, the cooling period was shortened. The system demonstrated an inherent low efficiency due to the large volume of water req...
To reduce building sector CO2 emissions, integrating renewable energy and thermal energy storage ... more To reduce building sector CO2 emissions, integrating renewable energy and thermal energy storage (TES) into building design is crucial. TES provides a way of storing thermal energy during high renewable energy production for use later during peak energy demand in buildings. The type of thermal energy stored in TES can be divided into three categories: sensible, latent, and sorption/chemical. Unlike sensible TES, latent TES and sorption/chemical TES have not been widely applied; however, they have the advantage of a higher energy density, making them effective for building applications. Most TES research focuses on technical design and rarely addresses its environmental, social, and cost impact. Life cycle assessment (LCA) is an internationally standardized method for evaluating the environmental impacts of any process. Life cycle sustainability assessment (LCSA) is an expansion of LCA, including economic and social sustainability assessments. This paper aims to provide a literature ...
Due to the demand for better quality and safety food as it provides health benefits, the study of... more Due to the demand for better quality and safety food as it provides health benefits, the study of innovative high pressure processing (HPP) is currently one of the most interesting researches in food processing and preservation. As an alternative to classical thermal processing, HPP has potential to produce high quality foods that are microbiologically safe with 'fresh-like' characteristics and improved functionalities. In present work, the use of HPP will be investigated for its ability to inactivate bacteria spores, the heat resistance microbes. Preliminary results show that it is possible to use HPP to inactivate microorganisms present in high sugar content foods, particularly in Manuka honey. Further investigation will be carried out to find an optimal combination of treatment pressure, temperature and time. This project will generate a new approach in honey processing which can guarantee the safety of honey without a compromise on its quality and natural freshness.
This study investigated the impact of individual and combination of different sources of heating ... more This study investigated the impact of individual and combination of different sources of heating (passive solar heating, electric oil-heater, and solar air heater) in a pilot-scale building containing phase change material (PCM) for a potential reduction in energy consumption while maintaining thermal comfort. Unlike most of the recent simulations and modelling studies, this impact was tested experimentally using two identical control and test huts located at the University of Auckland. The control hut was equipped with standard gypsum boards while the test hut had gypsum boards containing PCM (PureTemp 20, PT20). The study found that combining both active and passive solar heating with a temperature-controlled electric oil heater demonstrated the ability to provide significant energy savings and maintain thermal comfort in the test hut, most notably overnight. The suggested combination was tested over different weather conditions and with different temperature constraints to mainta...
Thermal energy storage (TES) has been identified by many researchers as one of the cost-effective... more Thermal energy storage (TES) has been identified by many researchers as one of the cost-effective solutions for not only storing excess or/wasted energy, but also improving systems’ reliability and thermal efficiency. Among TES, phase change materials (PCMs) are gaining more attention due to their ability to store a reasonably large quantity of heat within small temperature differences. Encapsulation is the cornerstone in expanding the applicability of the PCMs. Microencapsulation is a proven, viable method for containment and retention of PCMs in tiny shells. Currently, there are numerous methods available for synthesis of mPCMs, each of which has its own advantages and limitations. This review aims to discuss, up to date, the different manufacturing approaches to preparing PCM microcapsules (mPCMs). The review also highlights the different potential approaches used for the enhancement of their thermophysical properties, including heat transfer enhancement, supercooling suppression...
Microencapsulation of phase change materials (PCMs) remain a suitable option within building mate... more Microencapsulation of phase change materials (PCMs) remain a suitable option within building materials, as they contribute to the thermal mass and provide an energy buffer, an added benefit. This paper presents a novel method for the rapid fabrication of microencapsulated phase change materials (PCMs) at ambient conditions in a perfluoroalkoxy (PFA) coiled tube ultraviolet (UV) reactor. The objective of this study was to optimize key parameters such as the product yield and quality of the as-prepared microcapsules. Rubitherm® RT-21™ PCM was microencapsulated within shells of poly-methyl-methacrylate (PMMA) through a suspension emulsion polymerization approach, where the crosslinking of polymers was driven by UV radiations with an appropriate photoinitiator. The characteristics of the resulting PCM microcapsules were found to be affected by the volumetric flow rate of the emulsion inside the coiled tube reactor. Higher volumetric flow rates led to higher PCM contents and higher micro...
Older residential dwellings in New Zealand frequently suffer from poor indoor environmental quali... more Older residential dwellings in New Zealand frequently suffer from poor indoor environmental quality (IEQ) due to an ageing housing stock. Recent New Zealand surveys indicated around 50% of children live in houses that do not meet acceptable standards for thermal comfort. Children in these houses frequently experience respiratory conditions caused by dampness and mould during winter. New regulatory standards requiring a fixed heating source in the main living room of rental houses can increase rents and may result in the heating source not being utilized. This study evaluates an alternative low-cost portable air filter/sterilizer (PFUV) dehumidifier device for improving IEQ within the building envelope using Ultraviolet Germicidal Irradiation (UVGI) and a polyester filter (dual-10 30/30). This paper compares the effectiveness of the PFUV dehumidifier device and a conventional heat pump in terms of measured particulate matters as well as fungal profiles using Potato Dextrose Agar (PDA...
International Journal of Chemical Reactor Engineering, 2013
This study deals with a detailed numerical investigation of the microwave heating process in plas... more This study deals with a detailed numerical investigation of the microwave heating process in plastic pyrolysis. The pyrolysis of high-density polyethylene (HDPE) was studied using a single-mode microwave cavity, TE10 mode, at 2.45 GHz with two different absorbents, as carbon and silicon carbide, and the results were compared. The temperature distribution inside the sample was determined by solving the conservation equations coupled with the microwave and chemical kinetic equations. Lambert’s law was applied to describe the electromagnetic field in the microwave cavity. The effective heat capacity method was used to account for the latent heat in the melting range of plastic. The heat of the reaction was taken into account using first-order kinetic equations assuming a single-step reaction. One-dimensional model equations were solved using the finite difference method utilising MATLAB codes. The model developed in this study provides a better understanding of the fundamental mechanis...
Temperature distribution and solid-liquid interface positions were measured during melting and so... more Temperature distribution and solid-liquid interface positions were measured during melting and solidification of paraffin wax (mixture of pentacosane and hexacosane) contained in a cylindrical cell, with an insulated wall to achieve one dimensional heat flow. The lower face of the cell was subjected to a sudden temperature change, while the condition of no heat flux was maintained at the upper
Chemical Engineering and Processing: Process Intensification, 2006
Freeze concentration involves concentrating liquids partially by freezing water out of the soluti... more Freeze concentration involves concentrating liquids partially by freezing water out of the solution thus leaving behind a concentrate rich in its solutes. It is an expensive process that could benefit from alternative approaches that are more cost-effective. In this paper, freeze ...
Asia-Pacific Journal of Chemical Engineering, 2007
... On the other hand, several researchers have examined the use of algae/microalgae as a biomass... more ... On the other hand, several researchers have examined the use of algae/microalgae as a biomass source for the biodiesel production and other biofuel process. Algae or microalgae are simple plants that can carry out photosynthesis. They have the ability to convert water ...
Conventional gypsum wallboards impregnated with phase change materials (PCMs) are being developed... more Conventional gypsum wallboards impregnated with phase change materials (PCMs) are being developed as building materials with latent heat storage for passive solar applications at the Department of Chemical and Materials Engineering, University of Auckland, New Zealand. The PCM-gypsum wallboards have been projected to increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer
International Journal of Energy and Environmental Engineering, 2018
Public universities face the challenge of retrofitting the actual campus buildings into nearly ze... more Public universities face the challenge of retrofitting the actual campus buildings into nearly zero-energy buildings (NZEB). In this study, a novel methodology for evaluating historical energy use and renewable energy production for all the buildings of a university, including hourly, daily and monthly data assessments is presented. This analysis is useful as a baseline for comparisons with future energy retrofits and enables determining the current gap between actual energy indicators at building and campus levels and the established limits for NZEB non-residential buildings in the European Union. The methodology is applied to a case study at the University of Lleida, a typical average-size university in Spain. Results show a wide variation in energy use among campus buildings, ranging between 50 and 470 kWh/m 2 year. Constant or slightly increasing energy use and decreasing trends in renewable energy generation are observed. The daily electricity profiles have shown similar patterns among buildings and substantial potential energy savings during unoccupied periods. In the NZEB analysis, the average non-renewable primary energy use is about 4 times higher than the maximum estimated Spanish threshold range of 45-55 kWh/m 2 year. Deep energy renovation strategies are, thus, needed for universities to meet EU NZEB targets.
Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compound... more Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compounds are of great interest, as they have shown high antioxidant power and are correlated to many health benefits. Hence, traditional methods of extraction such as solvent extraction, Soxhlet extraction and novel extraction technologies such as ultrasound-assisted extraction and subcritical water extraction (SWE) have been investigated for the extraction of polyphenols. Scope and Approach: Generally, for traditional extractions, the total phenolic content (TPC) is highest at an extraction temperature of 60–80 °C. For this reason, polyphenols are regularly regarded as heat-labile compounds. However, in many studies that investigated the optimal temperature for subcritical water extraction (SWE), temperatures as high as 100–200 °C have been reported. These SWE extractions showed extremely high yields and antioxidant capacities at these temperatures. This paper aimed to examine the relevant lit...
Mathematical modelling is playing an important role in providing good understanding of heat and m... more Mathematical modelling is playing an important role in providing good understanding of heat and mass transfer in food processing. It has also been used to assess both microbial and biochemical changes in foods during processing. Both quality and safety must be assured, which would require good knowledge on how heat and moisture are transferred within the food materials. In this presentation, we shall illustrate examples showing how mathematics could be used to describe heat transfer, flow distribution, microbial inactivation and quality changes in three types of food processing applications in which experimental techniques failed to describe. These three applications are; (1) thermal sterilization of food in pouches, (2) pulsed electric field processing for pasteurisation, and (3) high pressure processing of food. We have used Computational Fluid Dynamic (CFD) software to describe the transport phenomena in these three different processing. The applications mentioned in 2 and 3 are ...
An improvement to existed methods of microbial spore inactivation is presented in this paper. A t... more An improvement to existed methods of microbial spore inactivation is presented in this paper. A treatment chamber was designed to hold elevated temperatures (above 100 °C) and pressure in the range of (3 atm). The innovative thermal assisted pulsed electric fields (PEF-ATS) processing was applied to inactivate Geobacillus sterothermophilus ATCC 10149 spores suspended in simulated milk ultrafiltrate (SMUF) of 50% (wt/wt) concentration. G. stearothermophilus spores are extremely resistant to high temperature and are also proven to be resistant to PEF processing in the range of 35 kv/cm. However, the combination of PEF and high temperature treatment conducted in this work shows significant inactivation of the G. stearothermophilus spores. A processing temperature/time of 115 °C/3.7 sec with an electric field intensity of 45 kv/cm showed 4.1 logmicrobial reductions, which are significantly less than usually obtained in thermal treatment alone.
Infant milk formula (IMF) is designed to mimic the composition of human milk (9–11 g protein/L); ... more Infant milk formula (IMF) is designed to mimic the composition of human milk (9–11 g protein/L); however, the standard protein content of IMF (15 g/L) is still a matter of controversy. In contrast to breastfed infants, excessive protein in IMF is associated with overweight and symptoms of metabolic syndrome in formula-fed infants. Moreover, the beta-lactoglobulin (β-Lg) content in cow milk is 3–4 g/L, whereas it is not present in human milk. It is considered to be a major reason for cow milk allergy in infants. In this respect, to modify protein composition, increasing the ratio of alpha-lactalbumin (α-Lac) to β-Lg would be a pragmatic approach to develop a hypoallergenic IMF with low protein content. Such a formula would ensure the necessary balance of essential amino acids, as 123 and 162 amino acid residues are available in α-Lac and β-Lg, respectively. Hence, in this study, a pasteurized form of hypoallergenic and low-protein ready-to-feed (RTF) formula, a new product, is develo...
In recent years, the concept of energy-efficient buildings has attracted widespread attention due... more In recent years, the concept of energy-efficient buildings has attracted widespread attention due to growing energy consumption in different types of buildings. The application of thermal energy storage (TES) systems, especially latent heat energy storage (LHES), has become a promising approach to improve thermal efficiency of buildings and hence reduces CO 2 emissions. One way to achieve this could be by implementing a model predictive control (MPC) strategy, using weather and electricity cost predictions. To this end, a heat exchanger unit containing a phase change material (PCM) as a LHES medium, thermally charged by 2 solar energy was incorporated into three versions of a standard building. This paper reports on the use of EnergyPlus software to simulate the heating demand profile of these buildings, with Solving Constraint Integer Programs (SCIP) as the optimization tool. After applying the MPC strategy, the energy costs of different building types were evaluated. Furthermore, the effect of the prediction horizon and decision time step of the MPC strategy, and PCM mass capacity on the performance of the MPC were all investigated in 1 and 7-day simulations. The results showed that by increasing the prediction horizon and PCM mass, more cost saving could be obtained. However, in terms of decision time step, although the study revealed that increasing it led to a higher energy saving, it made the system more sensitive to sharp changes as it failed to provide an accurate reading of the parameters and variables.
The energy consumption for space cooling is progressively increasing. Integrating renewable energ... more The energy consumption for space cooling is progressively increasing. Integrating renewable energy into space cooling systems is critical for reducing CO2 emissions from the building sector. The salt-based cooling system is an appealing alternative as it can be charged by solar energy. This system is based on the characteristic of endothermic salts, which generate a considerable cooling effect when dissolved in water. A screening test was performed in this work to evaluate the cooling performance of several endothermic salts. Furthermore, a laboratory-scale system was developed to demonstrate the endothermic salt-based thermal storage and cooling generation system. Temperature decreases up to 12.3 °C were observed in the system containing Potassium Chloride salt. The temperature drop was maintained after the system underwent a charging/discharging cycle; however, the cooling period was shortened. The system demonstrated an inherent low efficiency due to the large volume of water req...
To reduce building sector CO2 emissions, integrating renewable energy and thermal energy storage ... more To reduce building sector CO2 emissions, integrating renewable energy and thermal energy storage (TES) into building design is crucial. TES provides a way of storing thermal energy during high renewable energy production for use later during peak energy demand in buildings. The type of thermal energy stored in TES can be divided into three categories: sensible, latent, and sorption/chemical. Unlike sensible TES, latent TES and sorption/chemical TES have not been widely applied; however, they have the advantage of a higher energy density, making them effective for building applications. Most TES research focuses on technical design and rarely addresses its environmental, social, and cost impact. Life cycle assessment (LCA) is an internationally standardized method for evaluating the environmental impacts of any process. Life cycle sustainability assessment (LCSA) is an expansion of LCA, including economic and social sustainability assessments. This paper aims to provide a literature ...
Due to the demand for better quality and safety food as it provides health benefits, the study of... more Due to the demand for better quality and safety food as it provides health benefits, the study of innovative high pressure processing (HPP) is currently one of the most interesting researches in food processing and preservation. As an alternative to classical thermal processing, HPP has potential to produce high quality foods that are microbiologically safe with 'fresh-like' characteristics and improved functionalities. In present work, the use of HPP will be investigated for its ability to inactivate bacteria spores, the heat resistance microbes. Preliminary results show that it is possible to use HPP to inactivate microorganisms present in high sugar content foods, particularly in Manuka honey. Further investigation will be carried out to find an optimal combination of treatment pressure, temperature and time. This project will generate a new approach in honey processing which can guarantee the safety of honey without a compromise on its quality and natural freshness.
This study investigated the impact of individual and combination of different sources of heating ... more This study investigated the impact of individual and combination of different sources of heating (passive solar heating, electric oil-heater, and solar air heater) in a pilot-scale building containing phase change material (PCM) for a potential reduction in energy consumption while maintaining thermal comfort. Unlike most of the recent simulations and modelling studies, this impact was tested experimentally using two identical control and test huts located at the University of Auckland. The control hut was equipped with standard gypsum boards while the test hut had gypsum boards containing PCM (PureTemp 20, PT20). The study found that combining both active and passive solar heating with a temperature-controlled electric oil heater demonstrated the ability to provide significant energy savings and maintain thermal comfort in the test hut, most notably overnight. The suggested combination was tested over different weather conditions and with different temperature constraints to mainta...
Thermal energy storage (TES) has been identified by many researchers as one of the cost-effective... more Thermal energy storage (TES) has been identified by many researchers as one of the cost-effective solutions for not only storing excess or/wasted energy, but also improving systems’ reliability and thermal efficiency. Among TES, phase change materials (PCMs) are gaining more attention due to their ability to store a reasonably large quantity of heat within small temperature differences. Encapsulation is the cornerstone in expanding the applicability of the PCMs. Microencapsulation is a proven, viable method for containment and retention of PCMs in tiny shells. Currently, there are numerous methods available for synthesis of mPCMs, each of which has its own advantages and limitations. This review aims to discuss, up to date, the different manufacturing approaches to preparing PCM microcapsules (mPCMs). The review also highlights the different potential approaches used for the enhancement of their thermophysical properties, including heat transfer enhancement, supercooling suppression...
Microencapsulation of phase change materials (PCMs) remain a suitable option within building mate... more Microencapsulation of phase change materials (PCMs) remain a suitable option within building materials, as they contribute to the thermal mass and provide an energy buffer, an added benefit. This paper presents a novel method for the rapid fabrication of microencapsulated phase change materials (PCMs) at ambient conditions in a perfluoroalkoxy (PFA) coiled tube ultraviolet (UV) reactor. The objective of this study was to optimize key parameters such as the product yield and quality of the as-prepared microcapsules. Rubitherm® RT-21™ PCM was microencapsulated within shells of poly-methyl-methacrylate (PMMA) through a suspension emulsion polymerization approach, where the crosslinking of polymers was driven by UV radiations with an appropriate photoinitiator. The characteristics of the resulting PCM microcapsules were found to be affected by the volumetric flow rate of the emulsion inside the coiled tube reactor. Higher volumetric flow rates led to higher PCM contents and higher micro...
Older residential dwellings in New Zealand frequently suffer from poor indoor environmental quali... more Older residential dwellings in New Zealand frequently suffer from poor indoor environmental quality (IEQ) due to an ageing housing stock. Recent New Zealand surveys indicated around 50% of children live in houses that do not meet acceptable standards for thermal comfort. Children in these houses frequently experience respiratory conditions caused by dampness and mould during winter. New regulatory standards requiring a fixed heating source in the main living room of rental houses can increase rents and may result in the heating source not being utilized. This study evaluates an alternative low-cost portable air filter/sterilizer (PFUV) dehumidifier device for improving IEQ within the building envelope using Ultraviolet Germicidal Irradiation (UVGI) and a polyester filter (dual-10 30/30). This paper compares the effectiveness of the PFUV dehumidifier device and a conventional heat pump in terms of measured particulate matters as well as fungal profiles using Potato Dextrose Agar (PDA...
International Journal of Chemical Reactor Engineering, 2013
This study deals with a detailed numerical investigation of the microwave heating process in plas... more This study deals with a detailed numerical investigation of the microwave heating process in plastic pyrolysis. The pyrolysis of high-density polyethylene (HDPE) was studied using a single-mode microwave cavity, TE10 mode, at 2.45 GHz with two different absorbents, as carbon and silicon carbide, and the results were compared. The temperature distribution inside the sample was determined by solving the conservation equations coupled with the microwave and chemical kinetic equations. Lambert’s law was applied to describe the electromagnetic field in the microwave cavity. The effective heat capacity method was used to account for the latent heat in the melting range of plastic. The heat of the reaction was taken into account using first-order kinetic equations assuming a single-step reaction. One-dimensional model equations were solved using the finite difference method utilising MATLAB codes. The model developed in this study provides a better understanding of the fundamental mechanis...
Temperature distribution and solid-liquid interface positions were measured during melting and so... more Temperature distribution and solid-liquid interface positions were measured during melting and solidification of paraffin wax (mixture of pentacosane and hexacosane) contained in a cylindrical cell, with an insulated wall to achieve one dimensional heat flow. The lower face of the cell was subjected to a sudden temperature change, while the condition of no heat flux was maintained at the upper
Chemical Engineering and Processing: Process Intensification, 2006
Freeze concentration involves concentrating liquids partially by freezing water out of the soluti... more Freeze concentration involves concentrating liquids partially by freezing water out of the solution thus leaving behind a concentrate rich in its solutes. It is an expensive process that could benefit from alternative approaches that are more cost-effective. In this paper, freeze ...
Asia-Pacific Journal of Chemical Engineering, 2007
... On the other hand, several researchers have examined the use of algae/microalgae as a biomass... more ... On the other hand, several researchers have examined the use of algae/microalgae as a biomass source for the biodiesel production and other biofuel process. Algae or microalgae are simple plants that can carry out photosynthesis. They have the ability to convert water ...
Conventional gypsum wallboards impregnated with phase change materials (PCMs) are being developed... more Conventional gypsum wallboards impregnated with phase change materials (PCMs) are being developed as building materials with latent heat storage for passive solar applications at the Department of Chemical and Materials Engineering, University of Auckland, New Zealand. The PCM-gypsum wallboards have been projected to increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer
International Journal of Energy and Environmental Engineering, 2018
Public universities face the challenge of retrofitting the actual campus buildings into nearly ze... more Public universities face the challenge of retrofitting the actual campus buildings into nearly zero-energy buildings (NZEB). In this study, a novel methodology for evaluating historical energy use and renewable energy production for all the buildings of a university, including hourly, daily and monthly data assessments is presented. This analysis is useful as a baseline for comparisons with future energy retrofits and enables determining the current gap between actual energy indicators at building and campus levels and the established limits for NZEB non-residential buildings in the European Union. The methodology is applied to a case study at the University of Lleida, a typical average-size university in Spain. Results show a wide variation in energy use among campus buildings, ranging between 50 and 470 kWh/m 2 year. Constant or slightly increasing energy use and decreasing trends in renewable energy generation are observed. The daily electricity profiles have shown similar patterns among buildings and substantial potential energy savings during unoccupied periods. In the NZEB analysis, the average non-renewable primary energy use is about 4 times higher than the maximum estimated Spanish threshold range of 45-55 kWh/m 2 year. Deep energy renovation strategies are, thus, needed for universities to meet EU NZEB targets.
Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compound... more Background: Polyphenols are a set of bioactive compounds commonly found in plants. These compounds are of great interest, as they have shown high antioxidant power and are correlated to many health benefits. Hence, traditional methods of extraction such as solvent extraction, Soxhlet extraction and novel extraction technologies such as ultrasound-assisted extraction and subcritical water extraction (SWE) have been investigated for the extraction of polyphenols. Scope and Approach: Generally, for traditional extractions, the total phenolic content (TPC) is highest at an extraction temperature of 60–80 °C. For this reason, polyphenols are regularly regarded as heat-labile compounds. However, in many studies that investigated the optimal temperature for subcritical water extraction (SWE), temperatures as high as 100–200 °C have been reported. These SWE extractions showed extremely high yields and antioxidant capacities at these temperatures. This paper aimed to examine the relevant lit...
Mathematical modelling is playing an important role in providing good understanding of heat and m... more Mathematical modelling is playing an important role in providing good understanding of heat and mass transfer in food processing. It has also been used to assess both microbial and biochemical changes in foods during processing. Both quality and safety must be assured, which would require good knowledge on how heat and moisture are transferred within the food materials. In this presentation, we shall illustrate examples showing how mathematics could be used to describe heat transfer, flow distribution, microbial inactivation and quality changes in three types of food processing applications in which experimental techniques failed to describe. These three applications are; (1) thermal sterilization of food in pouches, (2) pulsed electric field processing for pasteurisation, and (3) high pressure processing of food. We have used Computational Fluid Dynamic (CFD) software to describe the transport phenomena in these three different processing. The applications mentioned in 2 and 3 are ...
An improvement to existed methods of microbial spore inactivation is presented in this paper. A t... more An improvement to existed methods of microbial spore inactivation is presented in this paper. A treatment chamber was designed to hold elevated temperatures (above 100 °C) and pressure in the range of (3 atm). The innovative thermal assisted pulsed electric fields (PEF-ATS) processing was applied to inactivate Geobacillus sterothermophilus ATCC 10149 spores suspended in simulated milk ultrafiltrate (SMUF) of 50% (wt/wt) concentration. G. stearothermophilus spores are extremely resistant to high temperature and are also proven to be resistant to PEF processing in the range of 35 kv/cm. However, the combination of PEF and high temperature treatment conducted in this work shows significant inactivation of the G. stearothermophilus spores. A processing temperature/time of 115 °C/3.7 sec with an electric field intensity of 45 kv/cm showed 4.1 logmicrobial reductions, which are significantly less than usually obtained in thermal treatment alone.
Infant milk formula (IMF) is designed to mimic the composition of human milk (9–11 g protein/L); ... more Infant milk formula (IMF) is designed to mimic the composition of human milk (9–11 g protein/L); however, the standard protein content of IMF (15 g/L) is still a matter of controversy. In contrast to breastfed infants, excessive protein in IMF is associated with overweight and symptoms of metabolic syndrome in formula-fed infants. Moreover, the beta-lactoglobulin (β-Lg) content in cow milk is 3–4 g/L, whereas it is not present in human milk. It is considered to be a major reason for cow milk allergy in infants. In this respect, to modify protein composition, increasing the ratio of alpha-lactalbumin (α-Lac) to β-Lg would be a pragmatic approach to develop a hypoallergenic IMF with low protein content. Such a formula would ensure the necessary balance of essential amino acids, as 123 and 162 amino acid residues are available in α-Lac and β-Lg, respectively. Hence, in this study, a pasteurized form of hypoallergenic and low-protein ready-to-feed (RTF) formula, a new product, is develo...
In recent years, the concept of energy-efficient buildings has attracted widespread attention due... more In recent years, the concept of energy-efficient buildings has attracted widespread attention due to growing energy consumption in different types of buildings. The application of thermal energy storage (TES) systems, especially latent heat energy storage (LHES), has become a promising approach to improve thermal efficiency of buildings and hence reduces CO 2 emissions. One way to achieve this could be by implementing a model predictive control (MPC) strategy, using weather and electricity cost predictions. To this end, a heat exchanger unit containing a phase change material (PCM) as a LHES medium, thermally charged by 2 solar energy was incorporated into three versions of a standard building. This paper reports on the use of EnergyPlus software to simulate the heating demand profile of these buildings, with Solving Constraint Integer Programs (SCIP) as the optimization tool. After applying the MPC strategy, the energy costs of different building types were evaluated. Furthermore, the effect of the prediction horizon and decision time step of the MPC strategy, and PCM mass capacity on the performance of the MPC were all investigated in 1 and 7-day simulations. The results showed that by increasing the prediction horizon and PCM mass, more cost saving could be obtained. However, in terms of decision time step, although the study revealed that increasing it led to a higher energy saving, it made the system more sensitive to sharp changes as it failed to provide an accurate reading of the parameters and variables.
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Papers by Mohammed Farid