This work deals with the optimization of the icing process in an ice storage system.It is focused on the improvement of the icing behavior,which is to be achieved by different heat exchanger geometries in the ice stor...This work deals with the optimization of the icing process in an ice storage system.It is focused on the improvement of the icing behavior,which is to be achieved by different heat exchanger geometries in the ice storage tank.Therefore,CFD simulations were implemented to acquire and visualize the flow conditions,the temperature behavior and the growth of the ice layer during the cooling process.The results are compared and validated with model experiments on an experimental ice storage.It could be shown that the heat extraction of current technologies can be increased by more than 50% by using geometries that are more efficient.展开更多
Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energ...Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.展开更多
The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, ...The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.展开更多
This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up t...This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up to 21 days. Three freshwater fishes： Oreochromis sp. commonly known as Tilapia, Monopterus alba commonly known as Belut, Pangasius hypothalamus commonly known as Patin and marine fish Rastrellinger kanagurta commonly known as Kembung, Thunnus tonggol commonly known as Tongkol and Epinephelus sp. commonly known as Kerapu with average weight of 500-600 g were tested with storage time of 1, 3, 6, 9, 12, 15. 18 and 21 days kept ice storage. The Fatty Acid Methyl Ester （FAMEs） were prepared using one step method and were identified by using gas chromatograph Agilent 6890N equipped with flame ionization detector. Separation was performed by injecting 1μL of a sample into the capillary column DB-225MS column （30 m length × 0.250 mm diameter × 0.25 μm film thickness）. The fatty acids peaks were indentified using Agilent Technologies software 5988-5871EN and comparing their retention time against the authentic standard Supelco 37 Component FAME Mix. Statistical results showed that palmitic acid （CI6：0） were the major fatty acids among the saturated fatty acids （SFA） while oleic acid （C 18：1 n9） were the major monounsaturated fatty acids （MUFA） detected in each sample studied. Both linoliec acid （C 18：2n6） and arachadonic acid （C20：4n6） were predominant in total omega-6 polyunsaturated fatty acids （PUFA）. The essential fatty acids show prominent in ecosapentanoic acid （C20：5n3） and docosahexanoic acid （C22：6n3）. During ice storage polyunsaturated fatty acids （PUFA） and monounsaturated fatty acids （MUFA） decrease as the time of storage increase. There is significant decrease in polyene index （PI） index of all the species throughout the storage time, The PI in freshwater fishes decrease by 70% in Tilapia, 90.1% in Belut and 90.9% in Patin, while for marine fishes, PI in Kembung decreases by 67.8%, 85.7% in Kerapu and 65.93% in Tongkol during kept in ice storage. During ice storage, the percentage of EPA, DHA and ALA decrease in Tilapia （55.36%, 13.86% and 75.41%）, Belut （78.55%, 87.74 % and 74.53%） and Patin （82.45%, 40.0% and 82.10%）, respectively. The same result were also observed in the marine fishes where the percentage ofEPA, DHA and ALA decrease in Kembung （94.27%, 49.03% and 88.52%）, in Kerapu （73.03%, 88.18% and 38.73%） and Tongkol （70.05%, 38.24% and 57.14%）, respectively.展开更多
More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the ...More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the parameters of the indoor thermal property in phase change wallboard room and ordinary room,the effects of using phase change wallboards on indoor temperature in summer and air conditioning are obtained. The combination of construct enclosure and phase change materials can stabilize indoor temperature,improve indoor thermal comfort,reduce the frequency of the operation of air conditioning facility,cut the initial investment and operation expense,and meanwhile play an practical role in "the power balancing between the peak period and the valley period" policy. Through the experiment and the test of the effects exerted by phase change wallboard room and ordinary room on the indoor thermal environment,it is obtained that the phase change wallboard can reduce the fluctuation range of indoor temperature and the heat flow from the outside into indoor environment in summer. According to the study,it is found that the effect of cool-storing for 5 h is obvious. Through the analysis of the phase change wallboard without air conditioning in daytime,it is obtained that the frequency of the operation of air conditioning in phase change wallboard room is smaller than that in the ordinary room,which can prolong the lifetime of the facility and reduce operation expense.展开更多
The feasibility of employing stand-alone solar energy systems to meet demand-side loads depends strongly on providing appropriate solar energy storage. The present paper presents an efficient and economical, undergrou...The feasibility of employing stand-alone solar energy systems to meet demand-side loads depends strongly on providing appropriate solar energy storage. The present paper presents an efficient and economical, underground, thermal storage design to store hot water at a temperature of around 180?C required for running a double effect absorption chiller to cool a zero-energy-house in a desert environment. The performance of the design is evaluated employing a specially developed efficient mathematical model, for simulating the steady state radiation, convection and conduction processes occurring within the storage unit. The model is presented and analyzed, and employed to investigate the effects of various design parameters on storage efficiency. It is demonstrated that high storage efficiency may be reached, providing that appropriate insulation materials are used. It is also revealed that the soil conductivity has little effect on storage efficiency.展开更多
The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. S...The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Solar air-conditioning systems(SACS) are a promising solution for the reduction of conventional energy in buildings. The storage, especially the cold storage, plays an important role in SACS for unstable solar irradiation. In this paper, we took the absorption refrigerating unit as an example, and the solar air-conditioning system of an office building in Beijing was simulated. The accuracy of this model was verified by comparing with the SACS operation data. Moreover, based on the simulation data, the cold storage capacity of the solar air-conditioning system in different climatic regions was studied. The cold storage capacities of SACS in 20 cities distributed in different climate regions were studied systematically. The results simulated by our proposed model will be beneficial to the SACS design, and will enlarge the application of SACS.展开更多
The demand for cooling,such as that of products,spaces,and processes,has increased with the development of urbanization.Cold storage can shift the valley time of electric power to cold energy.Compared to the fixed col...The demand for cooling,such as that of products,spaces,and processes,has increased with the development of urbanization.Cold storage can shift the valley time of electric power to cold energy.Compared to the fixed cold storage routine,mobile cold storage can eliminate site limitations.Ice slurry,as a new functional fluid,has recently become a new source of technology in our social lives.First,the research status of ice slurry mobile cold storage is summarized.Applications in the engineering field,such as space cooling,fisheries,pipeline cleaning,firefighting,and other real scenarios,are listed.Subsequently,key issues are summarized to understand the theoretical basis of ice slurry mobile cold storage,including flow,heat transfer,and loss in the mobile cold storage process-related ice slurry.Both tap water ice slurry and binary ice slurry are distinguished and discussed.Finally,beneficial policy analyses and market prospects for its promotion are presented.In summary,ice slurry mobile cold storage is a popular research topic with broad prospects for energy storage.展开更多
Evaporative cooling(EC)is an ancient technique that is usually suitable for hot and dry climatic conditions due to the potential of water vapor evaporation.In this study,three kinds of evaporative cooling systems such...Evaporative cooling(EC)is an ancient technique that is usually suitable for hot and dry climatic conditions due to the potential of water vapor evaporation.In this study,three kinds of evaporative cooling systems such as direct EC(DEC),indirect EC(IEC),and Maisotsenko cycle EC(MEC)were locally developed at lab-scale.The performance of the systems was evaluated and compared for agricultural storage and livestock air-conditioning application in Pakistan.The experiments were performed for climatic conditions of Multan city(Pakistan)and the data were collected for hourly and daily basis.According to the results,it was observed that the DEC system has the ability to reduce the temperature of ambient air to an average of 8.5℃.Whilst IEC and MEC systems were able to drop the temperature of ambient air to an average of 6.8℃and 8.9℃,respectively.As per the results,the DEC system remained behind to provide desired conditions for livestock and agricultural product storage applications due to excessive humidity.On the other hand,the IEC and MEC systems can achieve the desired conditions for livestock application,but could not provide feasible conditions for various fruits and vegetable storage.The study concludes that hybrid EC systems can be developed to provide desired conditions for a wide range of applications under varying climatic conditions.展开更多
Effects of frozen-storage on fatty acids profiles and basic nutrient contents of two types of low-fat caprine milk ice creams were investigated during 0, 2, 4, 8 weeks of storage at -18°C. Two types of the experi...Effects of frozen-storage on fatty acids profiles and basic nutrient contents of two types of low-fat caprine milk ice creams were investigated during 0, 2, 4, 8 weeks of storage at -18°C. Two types of the experimental low-fat soft-serve goat ice creams were manufactured using whole (full-fat) milk and 2% fat goat milk with addition of commercial powdered vanilla flavor pre-mix containing 0.25% fat (Alpha Freeze, D466-A9047, Tampa, FL, USA). Fatty acid concentrations were quantified using a Thermo Electronic gas chromatography (GC)-MS (Model TRACE GC Ultra, Austin, TX, USA) equiped with an automatic sampler (Model AS-3000, Thermo Electronic Co.). The results showed that fat content was the only basic nutrient component exhibited the difference between the two types of ice creams, while no other components have shown differences between the two low-fat ice creams during the storage periods. The level of lauric acid (C12:0) was the highest among all 16 fatty acids, followed by palmitic (C16:0), linoleic (C18:1), and myristic acid (C14:0). The high levels of the medium chain fatty acids (C12:0 and C14:0) might have been derived from the goat milk as well as the palm oil asa part of the ingredients in the commercial ice cream premix. Among long chain fatty acids, palmitic acid (C16:0) was the highest, followed by oleic acid (C18:1) and stearic acid (C18:0). All of the long chain fatty acids contents were significantly higher (P < 0.05 or 0.01) in whole milk ice cream than those in 2% fat ice cream, except for the C22:0 and C24:00 acids. It was concluded that mean levels of the individual fatty acids in the caprine ice creams were significantly influenced by the types of milk fat used in the ice creams, but not by storage periods and storage × fat type interaction effects.展开更多
The most common method of shipping cells between institutes and companies is sending them frozen, usually treated with anti-freeze solution (most commonly DMSO because it is less toxic than many alternatives), and the...The most common method of shipping cells between institutes and companies is sending them frozen, usually treated with anti-freeze solution (most commonly DMSO because it is less toxic than many alternatives), and then packaging them in dry ice for shipment. However many countries place restrictions on dry ice shipments. An alternative to shipping frozen cell vials is to send flasks of growing cells in media. This also has problems because cells in media have limited viability and the flasks can leak. Here we report on an alternative method for shipping viable cells at ambient temperature without dry ice or in media filled flasks. In this study we report on the development and properties of HemSol?. This is an inexpensive, eco-friendly and protects cell integrity at ambient temperature while maintaining viability. We have previously shown that HemSol? protects platelet and RBC function in cold storage and circulating tumor cells up to 6 days. Therefore we wanted to know if HemSol? could also be used to transport live cells. Since HemSol? is a liquid, we experimented with encasing the cells with HemSol? and gelatin so as to prevent dry ice shipment of cells and circumvent the shipping of cells in media. We performed mock shipping experiments where cells were stored in HemSol? gel kept at room temperature on a lab benchtop and cells stored in dry ice was also kept on lab benchtop for up to 2 days. After the mock shipping period, we analyzed cells for their functions. Our results show that cells in HemSol? gel have greater than 95% viability and restored biological functions in 2 hours, whereas, cells shipped in dry ice required more than 24 hours to recover and needed media change to remove the DMSO.展开更多
The heat transfer process of ice formation on the outside of coil pipe in the ice storage tank with glycol solution as the second refrigerant was studied in this paper analytically and experimentally. A model was deve...The heat transfer process of ice formation on the outside of coil pipe in the ice storage tank with glycol solution as the second refrigerant was studied in this paper analytically and experimentally. A model was developed for the charging process and the conduction shape factor was applied. Also, the result obtained from the model was compared with the experimental data, both data were in agreement. The simple model is useful for the operation, design and optimization of the ice storage tank.展开更多
This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfr...This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfret(Pampus argenteus)stored at 4±1C in ice for 18 days.Fresh pomfret samples were obtained directly from the local fish market and transported to the laboratory with ice immediately.After being gutted,washed,filleted and trimmed in a water-ice mixture,samples were treated with different concentrations of GBLE(0.0 mg/mL,2.5 mg/mL,5.0 mg/mL,10.0 mg/mL)and packaged in Polyethylene bag,then stored in a refrigerator at 4±1C with ice.The results show that the shelf-life of untreated(0.0 mg/mL)pomfret samples was 8e9 days compared to 14e15 days for the GBLE1(2.5 mg/mL)treated group.The assessment results showed that different concentrations of GBLE had variable effects on preserving the texture parameters of acceptability limit,inhibit lipid oxidation,protein degradation,and microorganism growth.2.5 mg/mL of GBLE was the best for the preservation of pomfret during storage in ice.Therefore,there is potential use for GBLE as a preservative to extend the shelf-life of pomfret during chilled storage in ice.展开更多
The coordinated operation of controllable loads,such as air-conditioning load, and distributed generation sources in a smart grid environment has drawn significant attention in recent years. To improve the wind power ...The coordinated operation of controllable loads,such as air-conditioning load, and distributed generation sources in a smart grid environment has drawn significant attention in recent years. To improve the wind power utilization level in the distribution network and minimize the total system operation costs, this paper proposes a MILP(mixed integer linear programming) based approach to schedule the interruptible air-conditioning loads. In order to mitigate the uncertainties of the stochastic variables including wind power generation, ambient temperature change, and electricity retail price, the rolling horizon optimization(RHO) strategy is employed to continuously update the real-time information and proceed the control window. Moreover, to ensure the thermal comfort of customers, a novel two-parameter thermal model is introduced to calculate the indoor temperature variation more precisely. Simulations on a five node radial distribution network validate the efficiency of the proposed method.展开更多
In modern giant buildings,in order to improve energy utilization efficiency, cooling systems have developed from conventional chillers alone to smart energy net which includes chillers,ice storage,ground-source heat p...In modern giant buildings,in order to improve energy utilization efficiency, cooling systems have developed from conventional chillers alone to smart energy net which includes chillers,ice storage,ground-source heat pump,combined cooling heating and power( CCHP) and so on. The reasonable distribution of load is the key to guarantee such system in economical operation.Based on typical multi-type cooling system,economic models of different devices are presented and real-time intelligent economic scheduling with the approach of mixed integer programming is carried out. This algorithm has been applied in a certain building of Shanghai and results of simulation show that it is able to provide guidance on intelligent economic scheduling for multi-type cooling system.展开更多
Aims: The purpose of this work is to present the information approach as the only effective tool that allows us to calculate the uncertainty of any result of the study on the use of refrigeration equipment. Methodolog...Aims: The purpose of this work is to present the information approach as the only effective tool that allows us to calculate the uncertainty of any result of the study on the use of refrigeration equipment. Methodology: Using the definitions and formulas of information theory and similarity theory, the amount of information contained in a model of refrigeration equipment or process is calculated. This allows us to present formulas for calculating the relative and comparative uncertainties of the model without additional assumptions. Based on these formulas, the value of the inevitable threshold of the accuracy of the representation of the studied construction or process is determined. Results: Theoretically substantiated recommendations are formulated for choosing the most effective methods for analyzing refrigeration equipment are formulated. Conclusion: Having calculated the amount of information contained in the model, we presented practical methods for analyzing data on refrigeration equipment.展开更多
Cold-chain is a well-known method for reducing postharvest losses and low-cost cooling technology has not previously been tested as part of postharvest handling in Cambodia.The objective of this study was to measure p...Cold-chain is a well-known method for reducing postharvest losses and low-cost cooling technology has not previously been tested as part of postharvest handling in Cambodia.The objective of this study was to measure postharvest loss,quality changes,and safety concerns of Chinese cabbage(Brassica campestris L.ssp.pekinensis),during transportation using a cold-chain and compared to current farmers’employing ambient-chain practices.The quality and safety of Chinese cabbage were further evaluated by using ambient storage and Coolbot-powered cold chamber storage with and without modified atmosphere packaging(MAP).The samples were transported from farm sources in Battambang Province to a Phnom Penh specialty wholesale market.Postharvest loss was evaluated by measuring weight loss and visual quality measurements,in addition to various physiochemical and nutritional quality measurements.In addition,food safety was evaluated by quantifying total coliforms and Enterobacteriaceae,as well as the Salmonella spcies,and Escherichia coli.The results revealed that the cold-chain avoided postharvest loss,as indicated by produce weight gain of 14%on market arrival due to rehydration while inside the ice box during transport.In contrast,the traditional practice of ambient transport(28-31°C,62-78%relative humidity)resulted in very high postharvest loss,comprising 11%weight loss and 10%visual quality loss,for a total loss of 21%.Moreover,leaf yellowing found no marked influence on shelf life as L*,a*and b*values did not greatly differ with treatment.The total soluble solids(TSS),titratable acidity(TA),pH and vitamin C content were not significantly affected during storage.Food safety indicators(coliforms,Enterobacteriaceae,Salmonella and Escherichia coli)were lower in cold-chain storage than ambient-chain with lower counts of coliform bacteria,Enterobacteriaceae,and Salmonella spp.than traditionally handled produce.Escherichia coli was detected only in cold-chain produce.MAP had no effect on these food safety indicators.展开更多
During the observation of HCFC141b gas hydrate growth processes outside a ver- tical heat transfer tube, two exciting phenomena were found: fast nucleation of gas hydrate from melting ice, and the spontaneous permeati...During the observation of HCFC141b gas hydrate growth processes outside a ver- tical heat transfer tube, two exciting phenomena were found: fast nucleation of gas hydrate from melting ice, and the spontaneous permeation of water into the guest phases along the surface of heat transfer tube to form gas hydrate continuously. These two phenomena were explained with Zhou & Sloan’s hypothesis and the theory of surface free energy respectively, and a novel method of gas hydrate formation was presented——gas hydrate fast nucleation from melting ice and quiescent growth along heat transfer tube. There is no mechanic stirring in this method, the formed gas hydrates are compact, the ratio of unreacted interstitial water is little, which overcome the drawback of high energy cost and high ratio of unreacted interstitial water among the formed gas hydrates in the system with mechanic stirring. This finding will benefit the gas hydrate ap- plication technologies such as natural gas storage technology or cool storage technology with gas hydrate.展开更多
This study assessed the combined effect of slightly acidic electrolyzed water(SAEW)and slightly acidic electrolyzed water ice(SAEW-ice)on the quality of pomfrets over a period of 18 d of cold storage at 4°C.A pre...This study assessed the combined effect of slightly acidic electrolyzed water(SAEW)and slightly acidic electrolyzed water ice(SAEW-ice)on the quality of pomfrets over a period of 18 d of cold storage at 4°C.A presoak for 5 min in SAEW solution(22 mg/L)was used before the pomfrets were placed on SAEW-ice(pH:6.45;ORP:803 mV;ACC:18 mg/L);The changes in physicochemical properties(i.e.,pH,thiobarbituric acid,total volatile basic nitrogen and texture profile),microbial loads and sensory characteristics were all analyzed.Compared with the tap water(TW)group,the total bacterial counts of the SAEW group significantly decreased by 1.27 log10 CFU/g after immersion(p<0.05).The shelf life of the pomfrets was prolonged by 9 d by the combined treatment of SAEW and SAEW-ice during storage at 4℃.On the 18th day,the gumminess and chewiness values of the pomfrets in the SAEW+SAEW-ice group were 195 g and 3.97 mJ,respectively,which were significantly higher than those of the other groups(p<0.05).The results suggested that SAEW+SAEW-ice treatments have great potential as a novel method to maintain the quality and extend the shelf life of pomfrets during refrigerated storage.展开更多
文摘This work deals with the optimization of the icing process in an ice storage system.It is focused on the improvement of the icing behavior,which is to be achieved by different heat exchanger geometries in the ice storage tank.Therefore,CFD simulations were implemented to acquire and visualize the flow conditions,the temperature behavior and the growth of the ice layer during the cooling process.The results are compared and validated with model experiments on an experimental ice storage.It could be shown that the heat extraction of current technologies can be increased by more than 50% by using geometries that are more efficient.
文摘Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.
文摘The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.
文摘This study was conducted in the intention to identify and determine the fatty acid profile in freshwater fishes and marine fishes available at Malaysian wet market as well as its deterioration kept in ice storage up to 21 days. Three freshwater fishes： Oreochromis sp. commonly known as Tilapia, Monopterus alba commonly known as Belut, Pangasius hypothalamus commonly known as Patin and marine fish Rastrellinger kanagurta commonly known as Kembung, Thunnus tonggol commonly known as Tongkol and Epinephelus sp. commonly known as Kerapu with average weight of 500-600 g were tested with storage time of 1, 3, 6, 9, 12, 15. 18 and 21 days kept ice storage. The Fatty Acid Methyl Ester （FAMEs） were prepared using one step method and were identified by using gas chromatograph Agilent 6890N equipped with flame ionization detector. Separation was performed by injecting 1μL of a sample into the capillary column DB-225MS column （30 m length × 0.250 mm diameter × 0.25 μm film thickness）. The fatty acids peaks were indentified using Agilent Technologies software 5988-5871EN and comparing their retention time against the authentic standard Supelco 37 Component FAME Mix. Statistical results showed that palmitic acid （CI6：0） were the major fatty acids among the saturated fatty acids （SFA） while oleic acid （C 18：1 n9） were the major monounsaturated fatty acids （MUFA） detected in each sample studied. Both linoliec acid （C 18：2n6） and arachadonic acid （C20：4n6） were predominant in total omega-6 polyunsaturated fatty acids （PUFA）. The essential fatty acids show prominent in ecosapentanoic acid （C20：5n3） and docosahexanoic acid （C22：6n3）. During ice storage polyunsaturated fatty acids （PUFA） and monounsaturated fatty acids （MUFA） decrease as the time of storage increase. There is significant decrease in polyene index （PI） index of all the species throughout the storage time, The PI in freshwater fishes decrease by 70% in Tilapia, 90.1% in Belut and 90.9% in Patin, while for marine fishes, PI in Kembung decreases by 67.8%, 85.7% in Kerapu and 65.93% in Tongkol during kept in ice storage. During ice storage, the percentage of EPA, DHA and ALA decrease in Tilapia （55.36%, 13.86% and 75.41%）, Belut （78.55%, 87.74 % and 74.53%） and Patin （82.45%, 40.0% and 82.10%）, respectively. The same result were also observed in the marine fishes where the percentage ofEPA, DHA and ALA decrease in Kembung （94.27%, 49.03% and 88.52%）, in Kerapu （73.03%, 88.18% and 38.73%） and Tongkol （70.05%, 38.24% and 57.14%）, respectively.
基金Project(50878133) supported by the National Natural Science Foundation of ChinaProject(2007R37) supported by the Program Supporting Excellent Talents of Liaoning Province,China+1 种基金Project(2008S193) supported by the Key Laboratory Fund of Education Department of Liaoning Province,ChinaProject(1071211-1-00) supported by the Scientific and Technical Fund Project Subsidy of Shenyang,China
文摘More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the parameters of the indoor thermal property in phase change wallboard room and ordinary room,the effects of using phase change wallboards on indoor temperature in summer and air conditioning are obtained. The combination of construct enclosure and phase change materials can stabilize indoor temperature,improve indoor thermal comfort,reduce the frequency of the operation of air conditioning facility,cut the initial investment and operation expense,and meanwhile play an practical role in "the power balancing between the peak period and the valley period" policy. Through the experiment and the test of the effects exerted by phase change wallboard room and ordinary room on the indoor thermal environment,it is obtained that the phase change wallboard can reduce the fluctuation range of indoor temperature and the heat flow from the outside into indoor environment in summer. According to the study,it is found that the effect of cool-storing for 5 h is obvious. Through the analysis of the phase change wallboard without air conditioning in daytime,it is obtained that the frequency of the operation of air conditioning in phase change wallboard room is smaller than that in the ordinary room,which can prolong the lifetime of the facility and reduce operation expense.
文摘The feasibility of employing stand-alone solar energy systems to meet demand-side loads depends strongly on providing appropriate solar energy storage. The present paper presents an efficient and economical, underground, thermal storage design to store hot water at a temperature of around 180?C required for running a double effect absorption chiller to cool a zero-energy-house in a desert environment. The performance of the design is evaluated employing a specially developed efficient mathematical model, for simulating the steady state radiation, convection and conduction processes occurring within the storage unit. The model is presented and analyzed, and employed to investigate the effects of various design parameters on storage efficiency. It is demonstrated that high storage efficiency may be reached, providing that appropriate insulation materials are used. It is also revealed that the soil conductivity has little effect on storage efficiency.
基金funded by the National Key R&D Program of China (No. 2017YFC0702600)
文摘The building sector accounts for more than 40% of the global energy consumption. This consumption may be lowered by reducing building energy requirements and using renewable energy in building energy supply systems. Solar air-conditioning systems(SACS) are a promising solution for the reduction of conventional energy in buildings. The storage, especially the cold storage, plays an important role in SACS for unstable solar irradiation. In this paper, we took the absorption refrigerating unit as an example, and the solar air-conditioning system of an office building in Beijing was simulated. The accuracy of this model was verified by comparing with the SACS operation data. Moreover, based on the simulation data, the cold storage capacity of the solar air-conditioning system in different climatic regions was studied. The cold storage capacities of SACS in 20 cities distributed in different climate regions were studied systematically. The results simulated by our proposed model will be beneficial to the SACS design, and will enlarge the application of SACS.
基金The authors would like to thank the National Key Research and De-velopment Program of China(Grant No.:2021YFE0112500)the Eu-ropean Union’s Horizon 2020 Research and Innovation Program under the Marie Sklodowska-Curie grant agreement(Grant No.:101007976).
文摘The demand for cooling,such as that of products,spaces,and processes,has increased with the development of urbanization.Cold storage can shift the valley time of electric power to cold energy.Compared to the fixed cold storage routine,mobile cold storage can eliminate site limitations.Ice slurry,as a new functional fluid,has recently become a new source of technology in our social lives.First,the research status of ice slurry mobile cold storage is summarized.Applications in the engineering field,such as space cooling,fisheries,pipeline cleaning,firefighting,and other real scenarios,are listed.Subsequently,key issues are summarized to understand the theoretical basis of ice slurry mobile cold storage,including flow,heat transfer,and loss in the mobile cold storage process-related ice slurry.Both tap water ice slurry and binary ice slurry are distinguished and discussed.Finally,beneficial policy analyses and market prospects for its promotion are presented.In summary,ice slurry mobile cold storage is a popular research topic with broad prospects for energy storage.
基金funded by Bahauddin Zakariya University,Multan,Pakistan under the Director Research/ORIC grant entitled“Development and performance evaluation of prototypes of direct and indirect evaporative cooling-based air-conditioning systems”。
文摘Evaporative cooling(EC)is an ancient technique that is usually suitable for hot and dry climatic conditions due to the potential of water vapor evaporation.In this study,three kinds of evaporative cooling systems such as direct EC(DEC),indirect EC(IEC),and Maisotsenko cycle EC(MEC)were locally developed at lab-scale.The performance of the systems was evaluated and compared for agricultural storage and livestock air-conditioning application in Pakistan.The experiments were performed for climatic conditions of Multan city(Pakistan)and the data were collected for hourly and daily basis.According to the results,it was observed that the DEC system has the ability to reduce the temperature of ambient air to an average of 8.5℃.Whilst IEC and MEC systems were able to drop the temperature of ambient air to an average of 6.8℃and 8.9℃,respectively.As per the results,the DEC system remained behind to provide desired conditions for livestock and agricultural product storage applications due to excessive humidity.On the other hand,the IEC and MEC systems can achieve the desired conditions for livestock application,but could not provide feasible conditions for various fruits and vegetable storage.The study concludes that hybrid EC systems can be developed to provide desired conditions for a wide range of applications under varying climatic conditions.
文摘Effects of frozen-storage on fatty acids profiles and basic nutrient contents of two types of low-fat caprine milk ice creams were investigated during 0, 2, 4, 8 weeks of storage at -18°C. Two types of the experimental low-fat soft-serve goat ice creams were manufactured using whole (full-fat) milk and 2% fat goat milk with addition of commercial powdered vanilla flavor pre-mix containing 0.25% fat (Alpha Freeze, D466-A9047, Tampa, FL, USA). Fatty acid concentrations were quantified using a Thermo Electronic gas chromatography (GC)-MS (Model TRACE GC Ultra, Austin, TX, USA) equiped with an automatic sampler (Model AS-3000, Thermo Electronic Co.). The results showed that fat content was the only basic nutrient component exhibited the difference between the two types of ice creams, while no other components have shown differences between the two low-fat ice creams during the storage periods. The level of lauric acid (C12:0) was the highest among all 16 fatty acids, followed by palmitic (C16:0), linoleic (C18:1), and myristic acid (C14:0). The high levels of the medium chain fatty acids (C12:0 and C14:0) might have been derived from the goat milk as well as the palm oil asa part of the ingredients in the commercial ice cream premix. Among long chain fatty acids, palmitic acid (C16:0) was the highest, followed by oleic acid (C18:1) and stearic acid (C18:0). All of the long chain fatty acids contents were significantly higher (P < 0.05 or 0.01) in whole milk ice cream than those in 2% fat ice cream, except for the C22:0 and C24:00 acids. It was concluded that mean levels of the individual fatty acids in the caprine ice creams were significantly influenced by the types of milk fat used in the ice creams, but not by storage periods and storage × fat type interaction effects.
文摘The most common method of shipping cells between institutes and companies is sending them frozen, usually treated with anti-freeze solution (most commonly DMSO because it is less toxic than many alternatives), and then packaging them in dry ice for shipment. However many countries place restrictions on dry ice shipments. An alternative to shipping frozen cell vials is to send flasks of growing cells in media. This also has problems because cells in media have limited viability and the flasks can leak. Here we report on an alternative method for shipping viable cells at ambient temperature without dry ice or in media filled flasks. In this study we report on the development and properties of HemSol?. This is an inexpensive, eco-friendly and protects cell integrity at ambient temperature while maintaining viability. We have previously shown that HemSol? protects platelet and RBC function in cold storage and circulating tumor cells up to 6 days. Therefore we wanted to know if HemSol? could also be used to transport live cells. Since HemSol? is a liquid, we experimented with encasing the cells with HemSol? and gelatin so as to prevent dry ice shipment of cells and circumvent the shipping of cells in media. We performed mock shipping experiments where cells were stored in HemSol? gel kept at room temperature on a lab benchtop and cells stored in dry ice was also kept on lab benchtop for up to 2 days. After the mock shipping period, we analyzed cells for their functions. Our results show that cells in HemSol? gel have greater than 95% viability and restored biological functions in 2 hours, whereas, cells shipped in dry ice required more than 24 hours to recover and needed media change to remove the DMSO.
基金This work has been funded by 973 Proect (ProectNo.Gl999022308).
文摘The heat transfer process of ice formation on the outside of coil pipe in the ice storage tank with glycol solution as the second refrigerant was studied in this paper analytically and experimentally. A model was developed for the charging process and the conduction shape factor was applied. Also, the result obtained from the model was compared with the experimental data, both data were in agreement. The simple model is useful for the operation, design and optimization of the ice storage tank.
基金The study was financially supported by China Agriculture Research System(CARS-47),Shanghai promote agriculture by applying scientific&technological advances projects(2015No.4-12),Ability promotion project of Shanghai Municipal Science and Technology Commission Engineering Center(16DZ2280300)Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation(17DZ2293400).
文摘This study investigated the physical(L*,a*,b*,texture profile analyses,pH),chemical(TVB-N,K value and TBA),microbiological,amino acid content,and flavor effects that Gingko biloba leaf extract(GBLE)had on silver pomfret(Pampus argenteus)stored at 4±1C in ice for 18 days.Fresh pomfret samples were obtained directly from the local fish market and transported to the laboratory with ice immediately.After being gutted,washed,filleted and trimmed in a water-ice mixture,samples were treated with different concentrations of GBLE(0.0 mg/mL,2.5 mg/mL,5.0 mg/mL,10.0 mg/mL)and packaged in Polyethylene bag,then stored in a refrigerator at 4±1C with ice.The results show that the shelf-life of untreated(0.0 mg/mL)pomfret samples was 8e9 days compared to 14e15 days for the GBLE1(2.5 mg/mL)treated group.The assessment results showed that different concentrations of GBLE had variable effects on preserving the texture parameters of acceptability limit,inhibit lipid oxidation,protein degradation,and microorganism growth.2.5 mg/mL of GBLE was the best for the preservation of pomfret during storage in ice.Therefore,there is potential use for GBLE as a preservative to extend the shelf-life of pomfret during chilled storage in ice.
基金supported in part by the Faculty of Engineering and IT Early Career Researcher and Newly Appointed Staff Development Scheme 2016by the Hong Kong RGC Theme Based Research Scheme (No. T23-407/13 N, No. T23-701/ 14 N)by the 2015 Science and Technology Project of China Southern Power Grid (No. WYKJ00000027)
文摘The coordinated operation of controllable loads,such as air-conditioning load, and distributed generation sources in a smart grid environment has drawn significant attention in recent years. To improve the wind power utilization level in the distribution network and minimize the total system operation costs, this paper proposes a MILP(mixed integer linear programming) based approach to schedule the interruptible air-conditioning loads. In order to mitigate the uncertainties of the stochastic variables including wind power generation, ambient temperature change, and electricity retail price, the rolling horizon optimization(RHO) strategy is employed to continuously update the real-time information and proceed the control window. Moreover, to ensure the thermal comfort of customers, a novel two-parameter thermal model is introduced to calculate the indoor temperature variation more precisely. Simulations on a five node radial distribution network validate the efficiency of the proposed method.
基金the Project of Science and Technology Commission of Shanghai Municipality,China(No.12dz1200203)the Chongming Smart Grid National Sci-Tech Support Plan of China(No.2013BAA01B04)
文摘In modern giant buildings,in order to improve energy utilization efficiency, cooling systems have developed from conventional chillers alone to smart energy net which includes chillers,ice storage,ground-source heat pump,combined cooling heating and power( CCHP) and so on. The reasonable distribution of load is the key to guarantee such system in economical operation.Based on typical multi-type cooling system,economic models of different devices are presented and real-time intelligent economic scheduling with the approach of mixed integer programming is carried out. This algorithm has been applied in a certain building of Shanghai and results of simulation show that it is able to provide guidance on intelligent economic scheduling for multi-type cooling system.
文摘Aims: The purpose of this work is to present the information approach as the only effective tool that allows us to calculate the uncertainty of any result of the study on the use of refrigeration equipment. Methodology: Using the definitions and formulas of information theory and similarity theory, the amount of information contained in a model of refrigeration equipment or process is calculated. This allows us to present formulas for calculating the relative and comparative uncertainties of the model without additional assumptions. Based on these formulas, the value of the inevitable threshold of the accuracy of the representation of the studied construction or process is determined. Results: Theoretically substantiated recommendations are formulated for choosing the most effective methods for analyzing refrigeration equipment are formulated. Conclusion: Having calculated the amount of information contained in the model, we presented practical methods for analyzing data on refrigeration equipment.
基金the generous support of the American People provided through the United States Agency for International Development(USAID)to the following:Building Safe Vegetable Value Chains in Cambodia Program through the Feed the Future Horticulture Innovation Lab for Collaborative Research at the University of California Davis,subaward No.09-002945-130 to KL and GMYthe Borlaug Global Food Security Graduate Research Program as part of the U.S.government’s global hunger and food security initiative called Feed the Future,grant No.13076416 to KLand the Center of Excellence on Sustainable Agricultural Intensification and Nutrition(CE SAIN)of the Royal University of Agriculture through the Feed the Future Innovation Lab for Collaborative Research on Sustainable Intensification at Kansas State University(USAID)under Cooperative Agreement No.AID-OAA-L-14-00006.Additional support was provided by Sierra College and awards from the University of California President’s and Chancellor’s Postdoctoral Fellowship Program to KL.
文摘Cold-chain is a well-known method for reducing postharvest losses and low-cost cooling technology has not previously been tested as part of postharvest handling in Cambodia.The objective of this study was to measure postharvest loss,quality changes,and safety concerns of Chinese cabbage(Brassica campestris L.ssp.pekinensis),during transportation using a cold-chain and compared to current farmers’employing ambient-chain practices.The quality and safety of Chinese cabbage were further evaluated by using ambient storage and Coolbot-powered cold chamber storage with and without modified atmosphere packaging(MAP).The samples were transported from farm sources in Battambang Province to a Phnom Penh specialty wholesale market.Postharvest loss was evaluated by measuring weight loss and visual quality measurements,in addition to various physiochemical and nutritional quality measurements.In addition,food safety was evaluated by quantifying total coliforms and Enterobacteriaceae,as well as the Salmonella spcies,and Escherichia coli.The results revealed that the cold-chain avoided postharvest loss,as indicated by produce weight gain of 14%on market arrival due to rehydration while inside the ice box during transport.In contrast,the traditional practice of ambient transport(28-31°C,62-78%relative humidity)resulted in very high postharvest loss,comprising 11%weight loss and 10%visual quality loss,for a total loss of 21%.Moreover,leaf yellowing found no marked influence on shelf life as L*,a*and b*values did not greatly differ with treatment.The total soluble solids(TSS),titratable acidity(TA),pH and vitamin C content were not significantly affected during storage.Food safety indicators(coliforms,Enterobacteriaceae,Salmonella and Escherichia coli)were lower in cold-chain storage than ambient-chain with lower counts of coliform bacteria,Enterobacteriaceae,and Salmonella spp.than traditionally handled produce.Escherichia coli was detected only in cold-chain produce.MAP had no effect on these food safety indicators.
基金the Guangdong Provincial National Natural Science Foundation(Grant No.036996) the State Key Development Program for Basic Research of China(Grant No.G2000026306).
文摘During the observation of HCFC141b gas hydrate growth processes outside a ver- tical heat transfer tube, two exciting phenomena were found: fast nucleation of gas hydrate from melting ice, and the spontaneous permeation of water into the guest phases along the surface of heat transfer tube to form gas hydrate continuously. These two phenomena were explained with Zhou & Sloan’s hypothesis and the theory of surface free energy respectively, and a novel method of gas hydrate formation was presented——gas hydrate fast nucleation from melting ice and quiescent growth along heat transfer tube. There is no mechanic stirring in this method, the formed gas hydrates are compact, the ratio of unreacted interstitial water is little, which overcome the drawback of high energy cost and high ratio of unreacted interstitial water among the formed gas hydrates in the system with mechanic stirring. This finding will benefit the gas hydrate ap- plication technologies such as natural gas storage technology or cool storage technology with gas hydrate.
基金This study was financially supported by the National Key Research and Development Program of China(Grant No.2018YFD0701001,Grant No.2017YFB0404000).Any opinions,findings,and conclusions expressed in this publication are those of the authors and do not necessarily reflect the views of Zhejiang University.
文摘This study assessed the combined effect of slightly acidic electrolyzed water(SAEW)and slightly acidic electrolyzed water ice(SAEW-ice)on the quality of pomfrets over a period of 18 d of cold storage at 4°C.A presoak for 5 min in SAEW solution(22 mg/L)was used before the pomfrets were placed on SAEW-ice(pH:6.45;ORP:803 mV;ACC:18 mg/L);The changes in physicochemical properties(i.e.,pH,thiobarbituric acid,total volatile basic nitrogen and texture profile),microbial loads and sensory characteristics were all analyzed.Compared with the tap water(TW)group,the total bacterial counts of the SAEW group significantly decreased by 1.27 log10 CFU/g after immersion(p<0.05).The shelf life of the pomfrets was prolonged by 9 d by the combined treatment of SAEW and SAEW-ice during storage at 4℃.On the 18th day,the gumminess and chewiness values of the pomfrets in the SAEW+SAEW-ice group were 195 g and 3.97 mJ,respectively,which were significantly higher than those of the other groups(p<0.05).The results suggested that SAEW+SAEW-ice treatments have great potential as a novel method to maintain the quality and extend the shelf life of pomfrets during refrigerated storage.
