Although ammonium dinitramide(ADN)has been targeted as a potential green monopropellant in future space vehicles,its application potential in Micro-electrical–Mechanical System(MEMS)thrusters or microthrusters has be...Although ammonium dinitramide(ADN)has been targeted as a potential green monopropellant in future space vehicles,its application potential in Micro-electrical–Mechanical System(MEMS)thrusters or microthrusters has been seldom reported in open literature.In this paper,electrolytic decomposition of Ammonium Dinitramide(ADN)-based liquid monopropellant FLP-103 was carried out in an open chamber and MEMS thrusters were fabricated from poly-dimethylsiloxane(PDMS)to characterize the power consumption.Two thrust measurement methods were employed to investigate the electrolytic decomposition of FLP-103 in MEMS microthrusters.The results show that the monopropellant can be successfully ignited at room temperature through 80 V,0.1 A(8 W)using copper wire as electrodes.In the current thruster design,low thrust was obtained at FLP-103 flowrate of 40μl·min^(-1)but it generated the highest specific impulse,Isp,among all the flowrates tested.The experiments successfully demonstrated the potential application of electrolytic decomposition of FLP-103 in MEMS thrusters.展开更多
Farm-raised Pacific white shrimp (Litopenaeus vannamei) freshly harvested was evaluated for differences in proximal composition (moisture, ash, fat, and protein contents), water activity (aw), water retention index (W...Farm-raised Pacific white shrimp (Litopenaeus vannamei) freshly harvested was evaluated for differences in proximal composition (moisture, ash, fat, and protein contents), water activity (aw), water retention index (WRI), pH, colour and texture of up to 12 days of iced storage. Shortly after harvest, the proximate composition of shrimp appeared comparable across the farms. With ice storage, the pH significantly increased whereas fat content slowly decreased particularly between days 3 and 9 (P P > 0.05). Expressly, the protein content of shrimp specimens gradually decreased after day 8 (P aw) of shrimp specimens exhibited inconsequential differences during iced storage. While the lightness (L*) was significantly affected from day 2 onwards, the yellowness (b*) colour was so but only between days 6 and 10 (P < 0.05). In addition, the adhesiveness and hardness textures of shrimp specimens registered peak values at day 11. Overall, the physicochemical differences in farm-raised shrimp during iced storage of this study provide valuable information for relevant stakeholders of the shrimp industry. Importantly, the data provided at this study can serve as baseline for comparison and evaluation of preservative treatments applied to shrimp.展开更多
The microwave absorbing characteristics of basic cobalt carbonate,cobalt oxide(Co3O4),and the mixture of basic cobalt carbonate and cobalt oxide were investigated by means of microwave cavity perturbation,their temper...The microwave absorbing characteristics of basic cobalt carbonate,cobalt oxide(Co3O4),and the mixture of basic cobalt carbonate and cobalt oxide were investigated by means of microwave cavity perturbation,their temperature increasing curves were measured,and their ability to absorb microwave energy was also assessed based on the temperature increasing behavior of the material exposed to microwave field.Analyses of spectrum attenuation and relative frequency shift show that basic cobalt carbonate has weak capability to absorb microwave energy,while cobalt oxide has very strong capability to absorb microwave energy.It is feasible to thermally decompose basic cobalt carbonate though addition of small amount of cobalt oxide in microwave fields.The capability to absorb microwave energy of sample increases with an increase in mixing ratio of Co3O4.展开更多
The short half-lives due to the enzymatic degradation in blood, the lack of tissue targetability and the incapability to passively diffuse across the plasma membrane and smoothly traffic across the harsh intracelluar ...The short half-lives due to the enzymatic degradation in blood, the lack of tissue targetability and the incapability to passively diffuse across the plasma membrane and smoothly traffic across the harsh intracelluar environment are the major shortcomings for nucleic acid-based potential therapeutics, such as recombinant plasmid and antisense oligonucleotides or small interferring RNA (siRNA). Plasmid DNA containing a gene of interest could have immense impact as a promising therapeutic drug for treating genetic as well as acquired human diseases at the molecular level with high level of efficacy and precision. Thus both viral and non-viral synthetic vectors have been developed in the past decades to address the aforementioned challenges of naked DNA. While in the viral particles plasmid DNA is integrated into the viral genome, in most non-viral cases the DNA being anionic in nature is electrostatically associated with a cationic lipid or polymer forming lipoplex or polyplex, respectively, or a cationized inorganic gold, silica or iron oxide particle. Due to the potential immunogenicity and carcinogenicity issues with the viral particles, non-viral vectors have drawn much more attention for the clinical evaluation. However, the main concern of using non-biodegradable particles, specially the inorganic ones, is the adverse effects owing to their long term interactions with body components. We have recently developed biodegradable pH-sensitive inorganic nanoparticles of Mg/CaPi and carbonate apatite for efficient transgene delivery to primary, cancer and embryonic stem cells, by virtue of their high affinity binding with the DNA, ability to contact the cell membrane by ionic or ligand-receptor interactions and fast dissolution kinectis in endosomal acidic pH facilitating release of the DNA from the dissolving particles and also from the endosomes.展开更多
<strong>Background:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Spontaneous perinephric...<strong>Background:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Spontaneous perinephric hematoma with no associated pa</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">thology or provocation is a rare clinical phenomenon. The hematoma requires a two</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">year interval for a favorable hematoma resolution, and no associated hypertension or renal scarring. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Aims:</span><span style="font-family:Verdana;"></span></strong></b></span><b> </b><span style="font-family:Verdana;">Evidence of the efficacy of conservative management for spontaneous perinephric hematoma with a 2</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">year follow up. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Case Presentation:</span><span style="font-family:Verdana;"></span></strong></b></span><span style="font-family:Verdana;"> A previously healthy 38-year-old woman, presented with a sudden onset of left flank pain, associated with fatigue and pallor. The patient remained hemodynamically stable with no significant history or associated provocations identified. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Conclusion:</span><span style="font-family:Verdana;"></span></strong></b></span><b> </b><span style="font-family:Verdana;">The acute management strategy is favorable in such condition, as the hematoma remains under tam</span><span style="font-family:Verdana;">ponade in the retroperitoneal space, regardless of the size and organ dis</span><span style="font-family:Verdana;">placement. Closed observation, serial blood investigation and repeated CT scans are vital to assist in the decision to intervene.</span></span>展开更多
Sliding inguinal scrotal herniation of the bladder is rare but well-documented in the medical literature. The majority of the patients are asymptomatic and the hernia is usually diagnosed incidentally. Most authors ha...Sliding inguinal scrotal herniation of the bladder is rare but well-documented in the medical literature. The majority of the patients are asymptomatic and the hernia is usually diagnosed incidentally. Most authors had advocated surgically repair of the hernia with the reduction or resection of the bladder as the definitive management. We present an unusual case of inguinal scrotal herniation of the bladder presented as acute abdominal pain and treated with conservatively with urethral catheterization.展开更多
<strong>Background:</strong> Penile metastasis of colorectal carcinoma is a rare phenomenon in clinical setting. They normally manifest as penile lesion and acute urinary retention. However, presentation o...<strong>Background:</strong> Penile metastasis of colorectal carcinoma is a rare phenomenon in clinical setting. They normally manifest as penile lesion and acute urinary retention. However, presentation of priapism is exceedingly rare. <strong>Aims:</strong> Discussion of this rare presentation as well as the diagnostic processes and subsequent management. <strong>Case Presentation:</strong> A 54-year-old male with a history of colorectal cancer presents with acute urinary retention. Examination of the patient demonstrates a semi-erect penis, with multiple palpable nodules on the shaft and penile meatus. Histological and imaging findings indicate penile metastasis of colorectal cancer. <strong>Conclusion:</strong> Biopsy via cystoscopy is used to obtain definitive diagnosis of penile metastasis. Urinary drainage followed by further cancer intervention or palliative care is crucial for effective management.展开更多
A simple theoretical model of a heat pipe heat exchanger （HPHE） based on the ε-NTU method is presented. An iterative computer program was developed to predict the overall effectiveness of a counter-flow air-air loo...A simple theoretical model of a heat pipe heat exchanger （HPHE） based on the ε-NTU method is presented. An iterative computer program was developed to predict the overall effectiveness of a counter-flow air-air loop heat pipe heat exchanger （LHPHE）. A thermal resistance network approach for a single thermosyphon was first considered to determine the overall heat transfer coefficients and the NTU＇s for the evaporator and condenser sections. The model incorporated previously determined evaporating and condensing coefficients. The overall effectiveness of the 6, 4 and 2 row LHPHE was then predicted. The theoretical overall effectiveness was compared with experimental data obtained from a R410a filled LHPHE. The experimental overall effectiveness results compared very well with the simulated values, The results showed that the 6 row arrangement performed better than the 4 or 2 row arrangement in the experiment.展开更多
An experimental investigation was conducted to measure the temperature variation across the flow channel and to determine the performance of a natural convection solar air heater at various tilt angles from 15, 30 and...An experimental investigation was conducted to measure the temperature variation across the flow channel and to determine the performance of a natural convection solar air heater at various tilt angles from 15, 30 and 45°. The results of the temperature profile across the air gap showed that heat transfer from the absorber plate to the air stream was mainly by convection. At a particular section, mean air temperature could be calculated from the arithmetic mean of the temperature profile across the air gap to within ± 2 ℃. The axial air temperature distribution was non linear and did not increase much beyond 1 m of collector length. It tended to decrease towards the end of the collector. Overall glass, absorber plate and mean air temperatures over the entire length of the solar air heater could be determined by averaging the mean axial temperatures to within ± 2 ℃. The heater performed better as inclination increased.展开更多
System performance of solar water heaters depends upon collector and storage tank designs, solar radiation intensity and ambient temperature, amongst others. Evacuated glass tube collectors with U-tubes inside are les...System performance of solar water heaters depends upon collector and storage tank designs, solar radiation intensity and ambient temperature, amongst others. Evacuated glass tube collectors with U-tubes inside are less prone to leakages than the all-glass or the heat pipe types. U-tube solar water heaters suspended on walls and balconies could help overcome present day roof space restriction and increasing apartment-style housing. As such, their performance would depend upon its orientation when mounted in a vertical position. This paper reports the results of outdoor tests conducted on natural convection U-tube solar water heaters oriented towards different directions. Long and short term test procedures were employed to allow us to compare their performances as if they were tested simultaneously side-by-side.展开更多
OBJECTIVE： The increasing popularity and widespread use of traditional Chinese herbs as alterna- tive medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. Th...OBJECTIVE： The increasing popularity and widespread use of traditional Chinese herbs as alterna- tive medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. This study aimed to assess the level of microbial and heavy metal contamination in commonly consumed herbal medicine in Malay- sia and the effects of boiling on these contamination levels. METHODS： Four commonly consumed Chinese herbal medicine in Malaysia-＂Eight Treasure Herbal Tea＂, ＂Herbal Tea＂, Xiyangshen （Radix Panacis Quin- quefolii） and Dangshen （Radix Codonopsis） were evaluated in this study. Herbal medicines were pre- pared as boiled and non-boiled decoctions, and their microbial enumeration and heavy metal detection were conducted with plate assay and atom- ic absorption spectroscopy, respectively. RESULTS： Findings revealed that herbal medicines generally had 6 Iogl0cfu/mL microbial cells and that boiling had significantly reduced microbial contaminants, where no Bacillus spp., Staphylococcus spp. and Clostridium spp. were recovered. Heavy metals such as Mn, Cu, Cd, Pb, Fe and Zn were also detect- ed from all the samples, generally in low concentra- tions （〈1 mg/L） except for Mn （18.545 mg/L）. All de- coctions （after boiling） have reduced concentra- tions of Cu, while others were not significantly dif- ferent. Comparisons between samples with single and multi-herbs suggest level of microbial and metal contamination is not influenced by number of herbs in sample. CONCLUSION： Herbal medicines generally have microbial and heavy metal contaminants. However, the boiling process to generate decoctions was able to successfully reduce the number of microbes and Cu, ensuring safety of herbal medicines for consumption.展开更多
Application of silicon in high capacity electrodes of lithium ion battery suffers from stress effects and, in turn, affects voltage performance of battery. This paper established a reaction-diffusion-stress coupled mo...Application of silicon in high capacity electrodes of lithium ion battery suffers from stress effects and, in turn, affects voltage performance of battery. This paper established a reaction-diffusion-stress coupled model and investigated the stress induced voltage hysteresis with consideration of diffusion induced stress, surface effects and interparticle compression. It was found stress and stress induced voltage hysteresis depended on particle size. In big particles, diffusion induced stress is dominant and leads to significant hysteresis in both stress and voltage, indicating energy dissipation due to stress effects. In small particles, e.g.,radius of dozens nanometers, diffusion induced stress was negligible while surface effects played dominant role, leading to nearly vanished voltage hysteresis shifting away from equilibrium potential. According to calculation, particle sizes around 100 nm are appropriate choice for electrode design as both diffusion induced stress and surface effects are insignificant. Finally,interparticle compression pushed the stress hysteresis to compressive side and led to early termination of lithiation at cut-off voltage. Denser electrode would enhance this effect. It indicated that there must be a limit of mixing ratio of silicon because higher interparticle compressive stress due to more introduced silicon would impede the battery from fully charged.展开更多
The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper ...The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper reviews the milestone achievements during its first year of operation.The journal has filled an important niche,addressing some of the main priorities in the Global Report for Research on Infectious Diseases of Poverty.Highlights include the publication of three thematic issues on health systems,surveillance and response systems,as well as co-infection and syndemics.The thematic issues have foregrounded the importance and innovation that can be achieved through transdisciplinary research.The journal has been indexed by PubMed since April 2013,with the publication of a total of 38 articles.Finally,the journal is delivering to wider range readers both in developing and developed countries with sustained efforts with a focus on relevant and strategic information towards elimination of infectious diseases of poverty.展开更多
基金Supported by the Project of Ministry of Science,Technology and Innovation,Malaysia(MOSTI)(No.04-02-12-SF0160)
文摘Although ammonium dinitramide(ADN)has been targeted as a potential green monopropellant in future space vehicles,its application potential in Micro-electrical–Mechanical System(MEMS)thrusters or microthrusters has been seldom reported in open literature.In this paper,electrolytic decomposition of Ammonium Dinitramide(ADN)-based liquid monopropellant FLP-103 was carried out in an open chamber and MEMS thrusters were fabricated from poly-dimethylsiloxane(PDMS)to characterize the power consumption.Two thrust measurement methods were employed to investigate the electrolytic decomposition of FLP-103 in MEMS microthrusters.The results show that the monopropellant can be successfully ignited at room temperature through 80 V,0.1 A(8 W)using copper wire as electrodes.In the current thruster design,low thrust was obtained at FLP-103 flowrate of 40μl·min^(-1)but it generated the highest specific impulse,Isp,among all the flowrates tested.The experiments successfully demonstrated the potential application of electrolytic decomposition of FLP-103 in MEMS thrusters.
文摘Farm-raised Pacific white shrimp (Litopenaeus vannamei) freshly harvested was evaluated for differences in proximal composition (moisture, ash, fat, and protein contents), water activity (aw), water retention index (WRI), pH, colour and texture of up to 12 days of iced storage. Shortly after harvest, the proximate composition of shrimp appeared comparable across the farms. With ice storage, the pH significantly increased whereas fat content slowly decreased particularly between days 3 and 9 (P P > 0.05). Expressly, the protein content of shrimp specimens gradually decreased after day 8 (P aw) of shrimp specimens exhibited inconsequential differences during iced storage. While the lightness (L*) was significantly affected from day 2 onwards, the yellowness (b*) colour was so but only between days 6 and 10 (P < 0.05). In addition, the adhesiveness and hardness textures of shrimp specimens registered peak values at day 11. Overall, the physicochemical differences in farm-raised shrimp during iced storage of this study provide valuable information for relevant stakeholders of the shrimp industry. Importantly, the data provided at this study can serve as baseline for comparison and evaluation of preservative treatments applied to shrimp.
基金Project(50734007) supported by the National Natural Science Foundation of ChinaProject(2007GA002) supported by Project of Scienceand Technology of Yunnan Province,ChinaProject(2008-16) supported by the Analysis and Testing Foundation of Kunming Universityof Science and Technology,China
文摘The microwave absorbing characteristics of basic cobalt carbonate,cobalt oxide(Co3O4),and the mixture of basic cobalt carbonate and cobalt oxide were investigated by means of microwave cavity perturbation,their temperature increasing curves were measured,and their ability to absorb microwave energy was also assessed based on the temperature increasing behavior of the material exposed to microwave field.Analyses of spectrum attenuation and relative frequency shift show that basic cobalt carbonate has weak capability to absorb microwave energy,while cobalt oxide has very strong capability to absorb microwave energy.It is feasible to thermally decompose basic cobalt carbonate though addition of small amount of cobalt oxide in microwave fields.The capability to absorb microwave energy of sample increases with an increase in mixing ratio of Co3O4.
文摘The short half-lives due to the enzymatic degradation in blood, the lack of tissue targetability and the incapability to passively diffuse across the plasma membrane and smoothly traffic across the harsh intracelluar environment are the major shortcomings for nucleic acid-based potential therapeutics, such as recombinant plasmid and antisense oligonucleotides or small interferring RNA (siRNA). Plasmid DNA containing a gene of interest could have immense impact as a promising therapeutic drug for treating genetic as well as acquired human diseases at the molecular level with high level of efficacy and precision. Thus both viral and non-viral synthetic vectors have been developed in the past decades to address the aforementioned challenges of naked DNA. While in the viral particles plasmid DNA is integrated into the viral genome, in most non-viral cases the DNA being anionic in nature is electrostatically associated with a cationic lipid or polymer forming lipoplex or polyplex, respectively, or a cationized inorganic gold, silica or iron oxide particle. Due to the potential immunogenicity and carcinogenicity issues with the viral particles, non-viral vectors have drawn much more attention for the clinical evaluation. However, the main concern of using non-biodegradable particles, specially the inorganic ones, is the adverse effects owing to their long term interactions with body components. We have recently developed biodegradable pH-sensitive inorganic nanoparticles of Mg/CaPi and carbonate apatite for efficient transgene delivery to primary, cancer and embryonic stem cells, by virtue of their high affinity binding with the DNA, ability to contact the cell membrane by ionic or ligand-receptor interactions and fast dissolution kinectis in endosomal acidic pH facilitating release of the DNA from the dissolving particles and also from the endosomes.
文摘<strong>Background:</strong> <span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Spontaneous perinephric hematoma with no associated pa</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">thology or provocation is a rare clinical phenomenon. The hematoma requires a two</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">year interval for a favorable hematoma resolution, and no associated hypertension or renal scarring. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Aims:</span><span style="font-family:Verdana;"></span></strong></b></span><b> </b><span style="font-family:Verdana;">Evidence of the efficacy of conservative management for spontaneous perinephric hematoma with a 2</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">year follow up. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Case Presentation:</span><span style="font-family:Verdana;"></span></strong></b></span><span style="font-family:Verdana;"> A previously healthy 38-year-old woman, presented with a sudden onset of left flank pain, associated with fatigue and pallor. The patient remained hemodynamically stable with no significant history or associated provocations identified. </span><b><span style="font-family:Verdana;"><strong></strong></span><strong><span style="font-family:Verdana;">Conclusion:</span><span style="font-family:Verdana;"></span></strong></b></span><b> </b><span style="font-family:Verdana;">The acute management strategy is favorable in such condition, as the hematoma remains under tam</span><span style="font-family:Verdana;">ponade in the retroperitoneal space, regardless of the size and organ dis</span><span style="font-family:Verdana;">placement. Closed observation, serial blood investigation and repeated CT scans are vital to assist in the decision to intervene.</span></span>
文摘Sliding inguinal scrotal herniation of the bladder is rare but well-documented in the medical literature. The majority of the patients are asymptomatic and the hernia is usually diagnosed incidentally. Most authors had advocated surgically repair of the hernia with the reduction or resection of the bladder as the definitive management. We present an unusual case of inguinal scrotal herniation of the bladder presented as acute abdominal pain and treated with conservatively with urethral catheterization.
文摘<strong>Background:</strong> Penile metastasis of colorectal carcinoma is a rare phenomenon in clinical setting. They normally manifest as penile lesion and acute urinary retention. However, presentation of priapism is exceedingly rare. <strong>Aims:</strong> Discussion of this rare presentation as well as the diagnostic processes and subsequent management. <strong>Case Presentation:</strong> A 54-year-old male with a history of colorectal cancer presents with acute urinary retention. Examination of the patient demonstrates a semi-erect penis, with multiple palpable nodules on the shaft and penile meatus. Histological and imaging findings indicate penile metastasis of colorectal cancer. <strong>Conclusion:</strong> Biopsy via cystoscopy is used to obtain definitive diagnosis of penile metastasis. Urinary drainage followed by further cancer intervention or palliative care is crucial for effective management.
文摘A simple theoretical model of a heat pipe heat exchanger （HPHE） based on the ε-NTU method is presented. An iterative computer program was developed to predict the overall effectiveness of a counter-flow air-air loop heat pipe heat exchanger （LHPHE）. A thermal resistance network approach for a single thermosyphon was first considered to determine the overall heat transfer coefficients and the NTU＇s for the evaporator and condenser sections. The model incorporated previously determined evaporating and condensing coefficients. The overall effectiveness of the 6, 4 and 2 row LHPHE was then predicted. The theoretical overall effectiveness was compared with experimental data obtained from a R410a filled LHPHE. The experimental overall effectiveness results compared very well with the simulated values, The results showed that the 6 row arrangement performed better than the 4 or 2 row arrangement in the experiment.
文摘An experimental investigation was conducted to measure the temperature variation across the flow channel and to determine the performance of a natural convection solar air heater at various tilt angles from 15, 30 and 45°. The results of the temperature profile across the air gap showed that heat transfer from the absorber plate to the air stream was mainly by convection. At a particular section, mean air temperature could be calculated from the arithmetic mean of the temperature profile across the air gap to within ± 2 ℃. The axial air temperature distribution was non linear and did not increase much beyond 1 m of collector length. It tended to decrease towards the end of the collector. Overall glass, absorber plate and mean air temperatures over the entire length of the solar air heater could be determined by averaging the mean axial temperatures to within ± 2 ℃. The heater performed better as inclination increased.
文摘System performance of solar water heaters depends upon collector and storage tank designs, solar radiation intensity and ambient temperature, amongst others. Evacuated glass tube collectors with U-tubes inside are less prone to leakages than the all-glass or the heat pipe types. U-tube solar water heaters suspended on walls and balconies could help overcome present day roof space restriction and increasing apartment-style housing. As such, their performance would depend upon its orientation when mounted in a vertical position. This paper reports the results of outdoor tests conducted on natural convection U-tube solar water heaters oriented towards different directions. Long and short term test procedures were employed to allow us to compare their performances as if they were tested simultaneously side-by-side.
文摘OBJECTIVE： The increasing popularity and widespread use of traditional Chinese herbs as alterna- tive medicine have sparked an interest in understanding their biosafety, especially in decoctions that are consumed. This study aimed to assess the level of microbial and heavy metal contamination in commonly consumed herbal medicine in Malay- sia and the effects of boiling on these contamination levels. METHODS： Four commonly consumed Chinese herbal medicine in Malaysia-＂Eight Treasure Herbal Tea＂, ＂Herbal Tea＂, Xiyangshen （Radix Panacis Quin- quefolii） and Dangshen （Radix Codonopsis） were evaluated in this study. Herbal medicines were pre- pared as boiled and non-boiled decoctions, and their microbial enumeration and heavy metal detection were conducted with plate assay and atom- ic absorption spectroscopy, respectively. RESULTS： Findings revealed that herbal medicines generally had 6 Iogl0cfu/mL microbial cells and that boiling had significantly reduced microbial contaminants, where no Bacillus spp., Staphylococcus spp. and Clostridium spp. were recovered. Heavy metals such as Mn, Cu, Cd, Pb, Fe and Zn were also detect- ed from all the samples, generally in low concentra- tions （〈1 mg/L） except for Mn （18.545 mg/L）. All de- coctions （after boiling） have reduced concentra- tions of Cu, while others were not significantly dif- ferent. Comparisons between samples with single and multi-herbs suggest level of microbial and metal contamination is not influenced by number of herbs in sample. CONCLUSION： Herbal medicines generally have microbial and heavy metal contaminants. However, the boiling process to generate decoctions was able to successfully reduce the number of microbes and Cu, ensuring safety of herbal medicines for consumption.
基金the financial supports of the National Natural Science Foundation of China (Grant Nos. 11672170, 11332005, 11702166)the Natural Science Foundation of Shanghai (Grant No. 16ZR1412200)+1 种基金the support provided by the 2017 Monash University Malaysia Strategic Large Grant Scheme (Grant No. LG-2017-04-ENG)Advanced Engineering Programme Cluster funding
文摘Application of silicon in high capacity electrodes of lithium ion battery suffers from stress effects and, in turn, affects voltage performance of battery. This paper established a reaction-diffusion-stress coupled model and investigated the stress induced voltage hysteresis with consideration of diffusion induced stress, surface effects and interparticle compression. It was found stress and stress induced voltage hysteresis depended on particle size. In big particles, diffusion induced stress is dominant and leads to significant hysteresis in both stress and voltage, indicating energy dissipation due to stress effects. In small particles, e.g.,radius of dozens nanometers, diffusion induced stress was negligible while surface effects played dominant role, leading to nearly vanished voltage hysteresis shifting away from equilibrium potential. According to calculation, particle sizes around 100 nm are appropriate choice for electrode design as both diffusion induced stress and surface effects are insignificant. Finally,interparticle compression pushed the stress hysteresis to compressive side and led to early termination of lithiation at cut-off voltage. Denser electrode would enhance this effect. It indicated that there must be a limit of mixing ratio of silicon because higher interparticle compressive stress due to more introduced silicon would impede the battery from fully charged.
文摘The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper reviews the milestone achievements during its first year of operation.The journal has filled an important niche,addressing some of the main priorities in the Global Report for Research on Infectious Diseases of Poverty.Highlights include the publication of three thematic issues on health systems,surveillance and response systems,as well as co-infection and syndemics.The thematic issues have foregrounded the importance and innovation that can be achieved through transdisciplinary research.The journal has been indexed by PubMed since April 2013,with the publication of a total of 38 articles.Finally,the journal is delivering to wider range readers both in developing and developed countries with sustained efforts with a focus on relevant and strategic information towards elimination of infectious diseases of poverty.
