Taylor–Couette–Poiseuille(TCP)flow dominates the inner water-cooling circulation of canned motor reactor coolant pumps.Current research on TCP flow focuses on torque behaviors and flow regime transitions through exp...Taylor–Couette–Poiseuille(TCP)flow dominates the inner water-cooling circulation of canned motor reactor coolant pumps.Current research on TCP flow focuses on torque behaviors and flow regime transitions through experiments and simulations.However,research on axial flow resistance in a large Reynolds number turbulent state is not sufficient,especially for the various flow patterns.This study is devoted to investigating the influence of annular flow on the axial flow resistance of liquid in the coaxial cylinders of the stator and rotor in canned motor reactor coolant pumps,and predicting the coolant flow distribution between the upper coil cooling loop and lower bearing lubricating loop for safe operation.The axial flow resistance,coupled with the annular rotation,is experimentally investigated at a flow rate with an axial Reynolds number,Rea,from 2.6×10~3 to 6.0×10~3 and rotational Reynolds number,Ret,from 1.6×10~4 to 4.0×10~4.It is revealed that the axial flow frictional coe cient varies against the axial flow rate in linear relation sets with logarithmic coordinates,which shift up when the flow has a higher Ret.Further examination of the axial flow resistance,with the Rea extending to 3.5×10~5 and Ret up to 1.6×10~5,by simulation shows gentle variation rates in the axial flow frictional coe cients against the Rea.The relation curves with different Ret values converge when the Rea exceeds 3.5×10~5.A prediction model for TCP flow consisting of a polygonal approximation with logarithmic coordinates is developed to estimate the axial flow resistance against different axial and rotational Reynolds numbers for the evaluation of heat and mass transfer during transition states and the engineering design of the canned motor chamber structure.展开更多
Canned fish products are of increasing popularity in Australia;however current Australian nutrient databases do not include data on the percentage fish in these products. The objective of this study was to develop and...Canned fish products are of increasing popularity in Australia;however current Australian nutrient databases do not include data on the percentage fish in these products. The objective of this study was to develop and validate a database of the percentage fish and seafood contained in common canned fish and seafood products, for use in clinical trials. Six major supermarkets in the Illawarra region, NSW were audited for canned seafood products, and a database of reported percentage fish and seafood was developed. Mean + SD of each type of product was then determined. To validate the database, a representative sample of canned tuna products were weighed according to Codex Alimentarius methods. The weighed percentage fish was compared to reported percentage via independent sample t-test and Mann-Whitney test. Percentage fish data was collected for n = 214 canned fish products. The mean percentage fish in tuna products was 60.4% + 11.3% (n = 144), 72.0% + 14.7% in salmon products (n = 31) and 70.9% + 9.3% in sardine products (n = 23). There was no significant difference between the reported and weighed percentage fish. This database highlighted the substantial proportion of additional ingredients found in canned fish products. Given the popularity of such products, future studies measuring fish consumption should use a similar database to accurately measure fish intake.展开更多
The coast-down behavior is specially designed to satisfy the certain flow requirements in a special kind of canned motor pump when it is used in primary reactor coolant system. However, coast-down models once used are...The coast-down behavior is specially designed to satisfy the certain flow requirements in a special kind of canned motor pump when it is used in primary reactor coolant system. However, coast-down models once used are not suitable for designing ultra-large canned motor pumps with flywheels, in which case rotor's fluid resistance of canned motor is modeled by an empirical constant. When the size of canned motor increases, the error of empirical relationship becomes remarkable. In thrall to material's density and strength, flow resistance of coast-down behavior should be dynamically modeled accurately to reduce the demands of materials. In this paper, an improved analytical model is proposed to study barbell-like canned motor's coast-down characteristic based on basic torque behavior researches in Taylor-Couette flow and hydraulic coupler, where bearing's resistance is ignored. This model takes geometric and kinematic parameters into consideration. In addition, the influence of pressure and temperature is coupled into this coast-down model by using Reolands' viscosity relationship.Based on this model, coast-down behavior is studied and parameters sensitivity analysis is conducted from design view point. Parameters sensitivity analysis indicates that the density and distribution of materials have more remarkable influence on coast-down behavior compared with working condition and geometric parameters.展开更多
A uniform and effective heat distribution inside the canned milk is very crucial for achieving effective sterilization. It is extremely difficult to establish the temperature profile inside the canned milk during cont...A uniform and effective heat distribution inside the canned milk is very crucial for achieving effective sterilization. It is extremely difficult to establish the temperature profile inside the canned milk during continuous industrial scale operation. Computational fluid dynamics （CFD） simulation can be a useful tool to determine the temperature distribution of the fluid inside the can during the sterilization process. A CFD model was developed for the sterilization of canned milk at 121 ~C. The simulation results were validated with the experimental measurements of temperatures. The formation and movement of slowest heating zone （SHZ） during the sterilization process was tracked. Moreover, effect of can position （vertical and horizontal） during processing on milk temperature distribution inside the can was also investigated. Higher Grashof and Rayleigh numbers were obtained for vertical positioning of can compared to horizontal can processing. Further, effectiveness of the process was calculated based on F-value and these results reinforced the positive effect of horizontal position of can during the sterilization process.展开更多
In this study, we characterized and quantified vitamin B12 in canned apple snails, escargots, (boiled plain) using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Vitamin B12 contents of canned e...In this study, we characterized and quantified vitamin B12 in canned apple snails, escargots, (boiled plain) using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Vitamin B12 contents of canned escargots (boiled plain) were varied from approximately 0.8 μg/100g weight to approximately 5.5 μg/100g weight (mean values, 2.2 μg/100g weight). We identified vitamin B12 compounds from escargots using liquid chromatography-electrospray ionization/tandem mass spectrometry. We found that escargots contained true vitamin B12 and two inactive corrinoids, which were identified as factor IIIm (or methoxymensimidazolyl cyanocobamide), and factor S (or 2-methylmercaptoadenyl cyanocobamide). These results indicate that canned escargots (boiled plain) are not good sources of vitamin B12 for humans.展开更多
Xiaoxian Canned Food Factory is located at the foot ofthe beautiful Fenghuang Mountain, Xiao County Town, AnhuiProvince. It is a key export enterprise assigned by the Ministryof Light Industry with an annual output of...Xiaoxian Canned Food Factory is located at the foot ofthe beautiful Fenghuang Mountain, Xiao County Town, AnhuiProvince. It is a key export enterprise assigned by the Ministryof Light Industry with an annual output of 10,000 tons andexport volume of US＄4 million. It has fixed assets of RMB20million. The factory possesses a complete set of automaticequipment imported from Switzerland for manufacturing cannedfood, and has strong technical forces and ample raw materialsendowed by nature. The products come in 60 varieties underfour categories—meat, fruit, vegetable and drinks. Amongthese varieties, two won excellent product title from the ministryand six won excellent product title from the province. Two展开更多
In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur...In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur gas wells,we conducted a series of technical researches on casing protection,gas interference and vibration of deep-well ESP set in terms of a completion string design and support tools based on the completion modes of high-sulfur gas wells and the technical characteristics of ESP drainage gas recovery technologies.Simultaneously,drainage gas recovery technology was designed for Well L2.The research and application results show:firstly,the completion string system of high-sulfur gas wells composed of a canned ESP system and an anchor intubation packer can realize the normal operation of ESP and meet the requirements of casing protection;secondly,multiphase pump and bleeder line can be used to solve the problem of gas interference,the automatic reverse valve can be used to reduce the effect of ESP complex flow path on the flowing of the gas well,and the anchor intubation packer can be used to reduce the string vibration;thirdly,the canned ESP system designed in this paper is applicable toØ244.5 mm andØ177.8 mm casings,specifically,the ESP corresponding toØ244.5 mm casing has the maximum flow rate of 900 m^(3)/d and the maximum lift height of 4500 m,and that corresponding toØ177.8 mm casing has the maximum flow rate of 300 m^(3)/d and the maximum lift height of 3000 m.It is concluded that this research result provides a technical support for the implementation of ESP based drainage gas recovery technology in high-sulfur gas wells.展开更多
In Spain, certain population-based studies have shown high blood mercury (Hg) levels due to the high consumption of fish. Some studies have stated that one of the most consumed fish in Spain is canned tuna. Different ...In Spain, certain population-based studies have shown high blood mercury (Hg) levels due to the high consumption of fish. Some studies have stated that one of the most consumed fish in Spain is canned tuna. Different Spanish organisms consider that it is safe to consume canned tuna as it supposedly has a low mercury content, particularly in so-called light tuna. However, in Spain light tuna is mainly yellowfin and bigeye tuna, while in other countries it is mainly skipjack tuna. This study analyzed 36 cans of the most popular brands in Spain and examined the influence of the type of tuna, packaging medium (olive oil, sunflower seed oil, water or marinade), different brands, prices and expiration dates. Mercury concentrations (mg/kg) were measured by atomic absorption spectrometry and thermal decomposition amalgamation. The medians observed were (mg/kg): light tuna: 0.314;IQR: 0.205 - 0.594, white tuna: 0.338;IQR: 0.276 - 0.558, skipjack: 0.311;IQR: 0.299 - 0.322, frigate tuna: 0.219;IQR 0.182 - 0.257 and mackerel: 0.042;IQR 0.029 -?0.074. We found statistically significant differences between white tuna, light tuna and mackerel (p = 0.004);light tuna and mackerel (p = 0.002) and white tuna and mackerel (p = 0.006). However, we found no differences between white tuna and light tuna, or among packaging medium, brands, prices or expiration dates. The limit of 0.500 mg/kg of mercury in canned tuna was exceeded by the following percentages of the cans: 33.3% of light tuna, 16.7% of white tuna, and 0% of Skipjack, frigate tuna and mackerel. The mercury content of the cans of Spanish light tuna that were analyzed was variable and high. The results of this study indicate that stricter regulation of Hg in canned tuna is necessary. Until then, it is safer to recommend that vulnerable populations such as children and pregnant women consume canned mackerel, which has a markedly lower mercury content.展开更多
The present study sought to investigate the migration of target bisphenols,such as bisphenol-A(BPA),bisphenol-F(BPA),bisphenol-A diglycidyI ether(BADGE),bisphenol-A(2,3-dihydroxypropyl)glycidyl ether(BADGE.H_(2)O),bis...The present study sought to investigate the migration of target bisphenols,such as bisphenol-A(BPA),bisphenol-F(BPA),bisphenol-A diglycidyI ether(BADGE),bisphenol-A(2,3-dihydroxypropyl)glycidyl ether(BADGE.H_(2)O),bisphenol-A bis(2,3-dihydroxypropyl)ether(BADGE.2H_(2)O),and bisphenol F diglycidyl ether(BFDGE)in 102 samples of several canned seafood,namely canned Antarctic krill,scallop,oysters,mussel,clam,and mantis shrimp stored for months at different temperatures through a high-performance liquid chromatographic-fluorescence detector com-bined with a microwave-assisted extraction method.Except for BFDGE,the other five bisphenols were observed in most of the analyzed sam-ples.The canned shrimp showed the highest migration of BPA(0.089 mg/kg),exceeding the specific migration limit(SML)of BPA(0.05 mg/kg)specified by the European Union,while the migration levels of BADGE and its derivatives were within their SMLs.The migration behavior of bisphenols in the canned seafood was majorly affected by the analytes,storage conditions,and food types.BPA,BADGE.H_(2)O,and BADGE 2H_(2)O were characterized by a rapid migration during the first half of the shelf life,which increased with the increase of temperature,followed by a stabilization or decline of their concentrations for prolonged durations.Besides,the migration of target bisphenols was significantly influenced by the storage temperature in some seafood species.Notably,higher migration level of BPA was found in samples with higher fat content.The average dietary exposure of Chinese adults to BPA,BPF,BADGE.2H_(2)O,BADGE.H_(2)O,and BADGE of canned seafood was estimated at 11.69,1.21,6.47,8.74,and 4.71 ng/(kg d),respectively.The target hazard quotient values of all the analyzed bisphenols were below 1 for the Chinese adults,suggesting an insignificant exposure to these bisphenols through canned seafood consumption.展开更多
The comparison of experimental performance was studied for soda cans:longitudinal,transverse,diagonal,and smooth cases to improve the heat transfer rate and thermal performance of the solar air heater,in this study us...The comparison of experimental performance was studied for soda cans:longitudinal,transverse,diagonal,and smooth cases to improve the heat transfer rate and thermal performance of the solar air heater,in this study using a frame which has 1.5 m×0.5 m×0.05 m dimensions,the arrangements were placed on the absorber plate inside the channel,raising the air’s exit temperature as it passed by.The work was carried out for 4 cases in January in Baghdad,Iraq,under specific conditions to compare them to reach the ideal case and the best performance evaluation.When the collector was tilted 350 to the horizontal facing south,The range of mass flow rate was from 0.012 to 0.049 kg/s,and the range of Re was from 2000 to 10,000.The results show that the best Nusselt number in the diagonal AL cans case was increased to 112 at Re=10,000.Then the thermal efficiency increased to 98% accompanied by a moderate decrease in the fraction factor to reach 0.435.Aluminum cans also provide good economic support for solar systems due to their low cost,in addition to their recycling and reducing pollution.展开更多
Thermal processing of milk is an important unit operation to inactivate the spoilage organism and enzymes and thus increase the storage life of milk, It was very difficult to find out the temperature distribution insi...Thermal processing of milk is an important unit operation to inactivate the spoilage organism and enzymes and thus increase the storage life of milk, It was very difficult to find out the temperature distribution inside the cans during thermal processing. A Computational Fluid Dynamics （CFD） model was developed for thermization of milk in the can heating at 65℃ for the first time to determine the temperature distribution in the canned milk at stationary position. This developed CFD model was validated with the experimental measurements of temperature. The effects of thermization temperature on milk flow profile （velocity）, milk temperature and viscosity profiles inside the can during thermal process were investigated. Temperature profiles of milk in can at three different planes （i.e. top, middle and bottom plane） were studied. Moreover, thermization unit was calculated by correlating with temperature and it was found that maximum thermization unit was achieved at 540 s of thermal processing of milk in can.展开更多
Recyclable thermosets and thermoset composites with covalent adaptable networks(CANs,or dynamic covalent networks) have attracted considerable attention in recent years due to the combined merits of excellent mechanic...Recyclable thermosets and thermoset composites with covalent adaptable networks(CANs,or dynamic covalent networks) have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties,and chemical stabilities of traditional thermosets and recyclable,remoldable,and reprocessable attributes of thermoplastics.In this paper,we present an overview of the current strategies for synthesizing recyclable thermosets based on CANs,which involve recyclability,reprocessability,and possible rehealability.The recent literature examples are categorized based on the underlying controlled-cleavable linkages such as transesterification,DA/retro-DA chemistry,imine bonds,disulfide metathesis,dynamic B-O bonds,hemiaminals/hexahydrotriazines,and acetal linkages.Various degradation and malleability methods and resulting mechanical properties of the recycled thermosets and thermoset composites are presented.The emerging applications of recyclable thermosets and thermoset composites,with emphasis on their usage in adhesives,biomedical materials,wearable devices,coatings,and 3D printing materials,are also illustrated.Finally,a perspective on the challenges and future perspectives is briefly summarized.展开更多
目的通过对比分析去肾神经术(renal denervation,RD)和药物治疗对急性心肌梗死(acute myocardial infarction,AMI)后心力衰竭(heart failure,HF)大鼠模型心功能、肾素-血管紧张素-醛固酮系统、交感神经系统和心脏自主神经系统的影响,探...目的通过对比分析去肾神经术(renal denervation,RD)和药物治疗对急性心肌梗死(acute myocardial infarction,AMI)后心力衰竭(heart failure,HF)大鼠模型心功能、肾素-血管紧张素-醛固酮系统、交感神经系统和心脏自主神经系统的影响,探究RD与抗HF药物的疗效差异、最佳治疗时机以及疗效机制。方法 140只雄性Wistar大鼠,随机分为对照组、AMI组(心肌梗死组)、RD组(去肾神经组)、MI-1d+RD组(AMI后1天行RD)、MI-1d+Drugs组(AMI后1天予以药物治疗)、MI-4w+RD组(AMI后4周行RD)、MI-4w+Drugs组(AMI后4周予以药物治疗),每组各20只。AMI后1天及4周后分别行RD、β受体阻滞剂(β-blocker)+血管紧张素受体拮抗剂(ACEI)药物联合治疗。检测并记录AMI后8周各组大鼠模型的心功能、血浆脑钠尿肽(brain natriuretic peptide,BNP)、肾素、血管紧张素Ⅱ(Ang Ⅱ)、醛固酮(aldosterone,ALD)、去甲肾上腺素(norepinephrine,NE)水平,梗死心肌NE含量,心率和5 min内NN间期标准差(standard deviation of NN intervals,SDNN)。结果 AMI后8周,对照组、AMI组、RD组、MI-1d+RD组、MI-1d+Drugs组、MI-4w+RD组、MI-4w+Drugs组大鼠的左心室射血分数(left ventricular ejection fraction,LVEF)分别为85%、36%、82%、77%、65%、53%、45%。AMI组大鼠较对照组LVEF显著下降( P <0.05),血浆BNP、肾素、Ang Ⅱ、ALD、NE水平均显著增加( P <0.05),梗死心肌NE水平、HR显下降( P <0.05),SDNN显著增加( P <0.05)。MI-1d+RD组大鼠较AMI及MI-1d+Drugs组LVEF显著增加( P <0.05),血浆BNP、肾素、Ang II、ALD、NE水平均显著下降( P < 0.05 )。MI-1d+RD组、MI-1d+Drugs组大鼠较AMI组梗死心肌NE含量、心率显著均增加( P <0.05),SDNN显著下降( P <0.05);MI-4w+RD组、MI-4w+Drugs组大鼠较AMI组梗死心肌NE、心率及SDNN差异均无统计学意义( P >0.05)。结论 AMI后早期行RD改善心功能的疗效强于β受体阻滞剂与血管紧张素转化酶抑制剂联合治疗,其疗效机制包括抑制交感神经系统、肾素-血管紧张素-醛固酮系统活性以及调节心脏交感-迷走神经功能平衡。展开更多
The environmental issues associated with packaging materials have been attracting increasing attention.Life cycle assessment( LCA) is currently the main method used worldwide for evaluating green packaging materials. ...The environmental issues associated with packaging materials have been attracting increasing attention.Life cycle assessment( LCA) is currently the main method used worldwide for evaluating green packaging materials. In this study,the LCA method was used to evaluate the environmental impact of Baosteel’s newly developed process for manufacturing film-laminated steel packaging materials,from raw material mining,production,and processing to their storage,consumption,recycling,and final disposal. The environmental performance and main influencing factors were analyzed and compared. In addition,the life cycle environmental characteristics of film-laminated steel cans,tin-plated steel cans,and aluminum cans were compared. Of the main environmental indicators of the life cycle of the film-laminated steel can,the environmental load of the substrate accounts for the largest proportion,follow ed by electricity. The environmental impact of the production of film materials cannot be ignored. The overall environmental performance of film-laminated steel cans is better than that of aluminum cans.展开更多
Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, o...Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving “dopamine homeostasis” by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.展开更多
基金Supported by National Basic Research Program of China(973 Program)(Grant No.2015CB057302).
文摘Taylor–Couette–Poiseuille(TCP)flow dominates the inner water-cooling circulation of canned motor reactor coolant pumps.Current research on TCP flow focuses on torque behaviors and flow regime transitions through experiments and simulations.However,research on axial flow resistance in a large Reynolds number turbulent state is not sufficient,especially for the various flow patterns.This study is devoted to investigating the influence of annular flow on the axial flow resistance of liquid in the coaxial cylinders of the stator and rotor in canned motor reactor coolant pumps,and predicting the coolant flow distribution between the upper coil cooling loop and lower bearing lubricating loop for safe operation.The axial flow resistance,coupled with the annular rotation,is experimentally investigated at a flow rate with an axial Reynolds number,Rea,from 2.6×10~3 to 6.0×10~3 and rotational Reynolds number,Ret,from 1.6×10~4 to 4.0×10~4.It is revealed that the axial flow frictional coe cient varies against the axial flow rate in linear relation sets with logarithmic coordinates,which shift up when the flow has a higher Ret.Further examination of the axial flow resistance,with the Rea extending to 3.5×10~5 and Ret up to 1.6×10~5,by simulation shows gentle variation rates in the axial flow frictional coe cients against the Rea.The relation curves with different Ret values converge when the Rea exceeds 3.5×10~5.A prediction model for TCP flow consisting of a polygonal approximation with logarithmic coordinates is developed to estimate the axial flow resistance against different axial and rotational Reynolds numbers for the evaluation of heat and mass transfer during transition states and the engineering design of the canned motor chamber structure.
文摘Canned fish products are of increasing popularity in Australia;however current Australian nutrient databases do not include data on the percentage fish in these products. The objective of this study was to develop and validate a database of the percentage fish and seafood contained in common canned fish and seafood products, for use in clinical trials. Six major supermarkets in the Illawarra region, NSW were audited for canned seafood products, and a database of reported percentage fish and seafood was developed. Mean + SD of each type of product was then determined. To validate the database, a representative sample of canned tuna products were weighed according to Codex Alimentarius methods. The weighed percentage fish was compared to reported percentage via independent sample t-test and Mann-Whitney test. Percentage fish data was collected for n = 214 canned fish products. The mean percentage fish in tuna products was 60.4% + 11.3% (n = 144), 72.0% + 14.7% in salmon products (n = 31) and 70.9% + 9.3% in sardine products (n = 23). There was no significant difference between the reported and weighed percentage fish. This database highlighted the substantial proportion of additional ingredients found in canned fish products. Given the popularity of such products, future studies measuring fish consumption should use a similar database to accurately measure fish intake.
基金the National Basic Research Program(973)of China(Nos.2009CB724308 and 2015CB057302)the National Key Technology Research Project(Nos.2010ZX06001-13 and 2013ZX06002002-017)
文摘The coast-down behavior is specially designed to satisfy the certain flow requirements in a special kind of canned motor pump when it is used in primary reactor coolant system. However, coast-down models once used are not suitable for designing ultra-large canned motor pumps with flywheels, in which case rotor's fluid resistance of canned motor is modeled by an empirical constant. When the size of canned motor increases, the error of empirical relationship becomes remarkable. In thrall to material's density and strength, flow resistance of coast-down behavior should be dynamically modeled accurately to reduce the demands of materials. In this paper, an improved analytical model is proposed to study barbell-like canned motor's coast-down characteristic based on basic torque behavior researches in Taylor-Couette flow and hydraulic coupler, where bearing's resistance is ignored. This model takes geometric and kinematic parameters into consideration. In addition, the influence of pressure and temperature is coupled into this coast-down model by using Reolands' viscosity relationship.Based on this model, coast-down behavior is studied and parameters sensitivity analysis is conducted from design view point. Parameters sensitivity analysis indicates that the density and distribution of materials have more remarkable influence on coast-down behavior compared with working condition and geometric parameters.
文摘A uniform and effective heat distribution inside the canned milk is very crucial for achieving effective sterilization. It is extremely difficult to establish the temperature profile inside the canned milk during continuous industrial scale operation. Computational fluid dynamics （CFD） simulation can be a useful tool to determine the temperature distribution of the fluid inside the can during the sterilization process. A CFD model was developed for the sterilization of canned milk at 121 ~C. The simulation results were validated with the experimental measurements of temperatures. The formation and movement of slowest heating zone （SHZ） during the sterilization process was tracked. Moreover, effect of can position （vertical and horizontal） during processing on milk temperature distribution inside the can was also investigated. Higher Grashof and Rayleigh numbers were obtained for vertical positioning of can compared to horizontal can processing. Further, effectiveness of the process was calculated based on F-value and these results reinforced the positive effect of horizontal position of can during the sterilization process.
文摘In this study, we characterized and quantified vitamin B12 in canned apple snails, escargots, (boiled plain) using a microbiological assay based on Lactobacillus delbrueckii ATCC 7830. Vitamin B12 contents of canned escargots (boiled plain) were varied from approximately 0.8 μg/100g weight to approximately 5.5 μg/100g weight (mean values, 2.2 μg/100g weight). We identified vitamin B12 compounds from escargots using liquid chromatography-electrospray ionization/tandem mass spectrometry. We found that escargots contained true vitamin B12 and two inactive corrinoids, which were identified as factor IIIm (or methoxymensimidazolyl cyanocobamide), and factor S (or 2-methylmercaptoadenyl cyanocobamide). These results indicate that canned escargots (boiled plain) are not good sources of vitamin B12 for humans.
文摘Xiaoxian Canned Food Factory is located at the foot ofthe beautiful Fenghuang Mountain, Xiao County Town, AnhuiProvince. It is a key export enterprise assigned by the Ministryof Light Industry with an annual output of 10,000 tons andexport volume of US＄4 million. It has fixed assets of RMB20million. The factory possesses a complete set of automaticequipment imported from Switzerland for manufacturing cannedfood, and has strong technical forces and ample raw materialsendowed by nature. The products come in 60 varieties underfour categories—meat, fruit, vegetable and drinks. Amongthese varieties, two won excellent product title from the ministryand six won excellent product title from the province. Two
基金supported by the National Major Science and Technology Project“Demonstration development project of large carbonate gas field in the Sichuan Basin”(No.2016ZX05052)。
文摘In order to apply the electric submersible pump(ESP)based drainage gas recovery technology commonly used in conventional gas wells to high-sulfur gas wells,and meet the requirements of casing protection in high-sulfur gas wells,we conducted a series of technical researches on casing protection,gas interference and vibration of deep-well ESP set in terms of a completion string design and support tools based on the completion modes of high-sulfur gas wells and the technical characteristics of ESP drainage gas recovery technologies.Simultaneously,drainage gas recovery technology was designed for Well L2.The research and application results show:firstly,the completion string system of high-sulfur gas wells composed of a canned ESP system and an anchor intubation packer can realize the normal operation of ESP and meet the requirements of casing protection;secondly,multiphase pump and bleeder line can be used to solve the problem of gas interference,the automatic reverse valve can be used to reduce the effect of ESP complex flow path on the flowing of the gas well,and the anchor intubation packer can be used to reduce the string vibration;thirdly,the canned ESP system designed in this paper is applicable toØ244.5 mm andØ177.8 mm casings,specifically,the ESP corresponding toØ244.5 mm casing has the maximum flow rate of 900 m^(3)/d and the maximum lift height of 4500 m,and that corresponding toØ177.8 mm casing has the maximum flow rate of 300 m^(3)/d and the maximum lift height of 3000 m.It is concluded that this research result provides a technical support for the implementation of ESP based drainage gas recovery technology in high-sulfur gas wells.
文摘In Spain, certain population-based studies have shown high blood mercury (Hg) levels due to the high consumption of fish. Some studies have stated that one of the most consumed fish in Spain is canned tuna. Different Spanish organisms consider that it is safe to consume canned tuna as it supposedly has a low mercury content, particularly in so-called light tuna. However, in Spain light tuna is mainly yellowfin and bigeye tuna, while in other countries it is mainly skipjack tuna. This study analyzed 36 cans of the most popular brands in Spain and examined the influence of the type of tuna, packaging medium (olive oil, sunflower seed oil, water or marinade), different brands, prices and expiration dates. Mercury concentrations (mg/kg) were measured by atomic absorption spectrometry and thermal decomposition amalgamation. The medians observed were (mg/kg): light tuna: 0.314;IQR: 0.205 - 0.594, white tuna: 0.338;IQR: 0.276 - 0.558, skipjack: 0.311;IQR: 0.299 - 0.322, frigate tuna: 0.219;IQR 0.182 - 0.257 and mackerel: 0.042;IQR 0.029 -?0.074. We found statistically significant differences between white tuna, light tuna and mackerel (p = 0.004);light tuna and mackerel (p = 0.002) and white tuna and mackerel (p = 0.006). However, we found no differences between white tuna and light tuna, or among packaging medium, brands, prices or expiration dates. The limit of 0.500 mg/kg of mercury in canned tuna was exceeded by the following percentages of the cans: 33.3% of light tuna, 16.7% of white tuna, and 0% of Skipjack, frigate tuna and mackerel. The mercury content of the cans of Spanish light tuna that were analyzed was variable and high. The results of this study indicate that stricter regulation of Hg in canned tuna is necessary. Until then, it is safer to recommend that vulnerable populations such as children and pregnant women consume canned mackerel, which has a markedly lower mercury content.
基金the National Key Research and Development Program of China(No.2018YFD0901006).
文摘The present study sought to investigate the migration of target bisphenols,such as bisphenol-A(BPA),bisphenol-F(BPA),bisphenol-A diglycidyI ether(BADGE),bisphenol-A(2,3-dihydroxypropyl)glycidyl ether(BADGE.H_(2)O),bisphenol-A bis(2,3-dihydroxypropyl)ether(BADGE.2H_(2)O),and bisphenol F diglycidyl ether(BFDGE)in 102 samples of several canned seafood,namely canned Antarctic krill,scallop,oysters,mussel,clam,and mantis shrimp stored for months at different temperatures through a high-performance liquid chromatographic-fluorescence detector com-bined with a microwave-assisted extraction method.Except for BFDGE,the other five bisphenols were observed in most of the analyzed sam-ples.The canned shrimp showed the highest migration of BPA(0.089 mg/kg),exceeding the specific migration limit(SML)of BPA(0.05 mg/kg)specified by the European Union,while the migration levels of BADGE and its derivatives were within their SMLs.The migration behavior of bisphenols in the canned seafood was majorly affected by the analytes,storage conditions,and food types.BPA,BADGE.H_(2)O,and BADGE 2H_(2)O were characterized by a rapid migration during the first half of the shelf life,which increased with the increase of temperature,followed by a stabilization or decline of their concentrations for prolonged durations.Besides,the migration of target bisphenols was significantly influenced by the storage temperature in some seafood species.Notably,higher migration level of BPA was found in samples with higher fat content.The average dietary exposure of Chinese adults to BPA,BPF,BADGE.2H_(2)O,BADGE.H_(2)O,and BADGE of canned seafood was estimated at 11.69,1.21,6.47,8.74,and 4.71 ng/(kg d),respectively.The target hazard quotient values of all the analyzed bisphenols were below 1 for the Chinese adults,suggesting an insignificant exposure to these bisphenols through canned seafood consumption.
文摘The comparison of experimental performance was studied for soda cans:longitudinal,transverse,diagonal,and smooth cases to improve the heat transfer rate and thermal performance of the solar air heater,in this study using a frame which has 1.5 m×0.5 m×0.05 m dimensions,the arrangements were placed on the absorber plate inside the channel,raising the air’s exit temperature as it passed by.The work was carried out for 4 cases in January in Baghdad,Iraq,under specific conditions to compare them to reach the ideal case and the best performance evaluation.When the collector was tilted 350 to the horizontal facing south,The range of mass flow rate was from 0.012 to 0.049 kg/s,and the range of Re was from 2000 to 10,000.The results show that the best Nusselt number in the diagonal AL cans case was increased to 112 at Re=10,000.Then the thermal efficiency increased to 98% accompanied by a moderate decrease in the fraction factor to reach 0.435.Aluminum cans also provide good economic support for solar systems due to their low cost,in addition to their recycling and reducing pollution.
文摘Thermal processing of milk is an important unit operation to inactivate the spoilage organism and enzymes and thus increase the storage life of milk, It was very difficult to find out the temperature distribution inside the cans during thermal processing. A Computational Fluid Dynamics （CFD） model was developed for thermization of milk in the can heating at 65℃ for the first time to determine the temperature distribution in the canned milk at stationary position. This developed CFD model was validated with the experimental measurements of temperature. The effects of thermization temperature on milk flow profile （velocity）, milk temperature and viscosity profiles inside the can during thermal process were investigated. Temperature profiles of milk in can at three different planes （i.e. top, middle and bottom plane） were studied. Moreover, thermization unit was calculated by correlating with temperature and it was found that maximum thermization unit was achieved at 540 s of thermal processing of milk in can.
文摘Recyclable thermosets and thermoset composites with covalent adaptable networks(CANs,or dynamic covalent networks) have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties,and chemical stabilities of traditional thermosets and recyclable,remoldable,and reprocessable attributes of thermoplastics.In this paper,we present an overview of the current strategies for synthesizing recyclable thermosets based on CANs,which involve recyclability,reprocessability,and possible rehealability.The recent literature examples are categorized based on the underlying controlled-cleavable linkages such as transesterification,DA/retro-DA chemistry,imine bonds,disulfide metathesis,dynamic B-O bonds,hemiaminals/hexahydrotriazines,and acetal linkages.Various degradation and malleability methods and resulting mechanical properties of the recycled thermosets and thermoset composites are presented.The emerging applications of recyclable thermosets and thermoset composites,with emphasis on their usage in adhesives,biomedical materials,wearable devices,coatings,and 3D printing materials,are also illustrated.Finally,a perspective on the challenges and future perspectives is briefly summarized.
文摘目的通过对比分析去肾神经术(renal denervation,RD)和药物治疗对急性心肌梗死(acute myocardial infarction,AMI)后心力衰竭(heart failure,HF)大鼠模型心功能、肾素-血管紧张素-醛固酮系统、交感神经系统和心脏自主神经系统的影响,探究RD与抗HF药物的疗效差异、最佳治疗时机以及疗效机制。方法 140只雄性Wistar大鼠,随机分为对照组、AMI组(心肌梗死组)、RD组(去肾神经组)、MI-1d+RD组(AMI后1天行RD)、MI-1d+Drugs组(AMI后1天予以药物治疗)、MI-4w+RD组(AMI后4周行RD)、MI-4w+Drugs组(AMI后4周予以药物治疗),每组各20只。AMI后1天及4周后分别行RD、β受体阻滞剂(β-blocker)+血管紧张素受体拮抗剂(ACEI)药物联合治疗。检测并记录AMI后8周各组大鼠模型的心功能、血浆脑钠尿肽(brain natriuretic peptide,BNP)、肾素、血管紧张素Ⅱ(Ang Ⅱ)、醛固酮(aldosterone,ALD)、去甲肾上腺素(norepinephrine,NE)水平,梗死心肌NE含量,心率和5 min内NN间期标准差(standard deviation of NN intervals,SDNN)。结果 AMI后8周,对照组、AMI组、RD组、MI-1d+RD组、MI-1d+Drugs组、MI-4w+RD组、MI-4w+Drugs组大鼠的左心室射血分数(left ventricular ejection fraction,LVEF)分别为85%、36%、82%、77%、65%、53%、45%。AMI组大鼠较对照组LVEF显著下降( P <0.05),血浆BNP、肾素、Ang Ⅱ、ALD、NE水平均显著增加( P <0.05),梗死心肌NE水平、HR显下降( P <0.05),SDNN显著增加( P <0.05)。MI-1d+RD组大鼠较AMI及MI-1d+Drugs组LVEF显著增加( P <0.05),血浆BNP、肾素、Ang II、ALD、NE水平均显著下降( P < 0.05 )。MI-1d+RD组、MI-1d+Drugs组大鼠较AMI组梗死心肌NE含量、心率显著均增加( P <0.05),SDNN显著下降( P <0.05);MI-4w+RD组、MI-4w+Drugs组大鼠较AMI组梗死心肌NE、心率及SDNN差异均无统计学意义( P >0.05)。结论 AMI后早期行RD改善心功能的疗效强于β受体阻滞剂与血管紧张素转化酶抑制剂联合治疗,其疗效机制包括抑制交感神经系统、肾素-血管紧张素-醛固酮系统活性以及调节心脏交感-迷走神经功能平衡。
文摘The environmental issues associated with packaging materials have been attracting increasing attention.Life cycle assessment( LCA) is currently the main method used worldwide for evaluating green packaging materials. In this study,the LCA method was used to evaluate the environmental impact of Baosteel’s newly developed process for manufacturing film-laminated steel packaging materials,from raw material mining,production,and processing to their storage,consumption,recycling,and final disposal. The environmental performance and main influencing factors were analyzed and compared. In addition,the life cycle environmental characteristics of film-laminated steel cans,tin-plated steel cans,and aluminum cans were compared. Of the main environmental indicators of the life cycle of the film-laminated steel can,the environmental load of the substrate accounts for the largest proportion,follow ed by electricity. The environmental impact of the production of film materials cannot be ignored. The overall environmental performance of film-laminated steel cans is better than that of aluminum cans.
文摘Pediatric autoimmune neuropsychiatric disorders associated with group A streptococcal infections (PANDAS) is a concept that is used to characterize a subset of children with neuropsychiatric symptoms, tic disorders, or obsessive-compulsive disorder (OCD), whose symptoms are exacerbated by group A streptococcal (GAS) infection. PANDAS has been known to cause a sudden onset of reward deficiency syndrome (RDS). RDS includes multiple disorders that are characterized by dopaminergic signaling dysfunction in the brain reward cascade (BRC), which may result in addiction, depression, avoidant behaviors, anxiety, tic disorders, and/or OCD. According to research by Blum et al., the dopamine receptor D2 (DRD2) gene polymorphisms are important prevalent genetic determinants of RDS. The literature demonstrates that infections like Borrelia and Lyme, as well as other infections like group A beta-hemolytic streptococcal (GABHS), can cause an autoimmune reaction and associated antibodies target dopaminergic loci in the mesolimbic region of the brain, which interferes with brain function and potentially causes RDS-like symptoms/behaviors. The treatment of PANDAS remains controversial, especially since there have been limited efficacy studies to date. We propose an innovative potential treatment for PANDAS based on previous clinical trials using a pro-dopamine regulator known as KB220 variants. Our ongoing research suggests that achieving “dopamine homeostasis” by precision-guided DNA testing and pro-dopamine modulation could result in improved therapeutic outcomes.
