Screening Capsicum Accessions for Capsaicinoids Content

Ninety Capsicum accessions selected from the USDA Capsicum germplasm collection were screened for their capsaicinoids content using gas hromatography with nitrogen phosphorus detection (GC/NPD). Fresh fruits of Capsicum chinense, C. frutescens, C. baccatum, C. annuum, and C. pubescens were extracted with methanol and analyzed for capsaicin, dihydrocapsaicin, and nordihydrocapsaicin. Mass spectrometry of the fruit crude extracts indicated that the molecular ions at m/z 305, 307, and 293, which correspond to capsaicin, dihydrocapsaicin, and nordihydrocapsaicin, respectively, have a common benzyl cation fragment at m/z 137 that can be used for monitoring capsaicinoids in pepper fruit extracts. Capsaicin and dihydrocapsaicin were the dominant capsaicinoids detected. Capsaicin concentrations were typically greater than dihydrocapsaicin. Concentrations of total capsaicinoids varied from not detectable to 11.2 mg fruit^?1. Statistical analysis revealed that accession PI-441624 (C. chinense) had the highest capsaicin content (2.9 mg g^?1 fresh fruit) and accession PI-497984 (C. frutescens) had the highest dihydrocapsaicin content (2.3 mg g^?1 fresh fruit). Genebank accessions PI-439522 (C. frutescens) and PI-497984 contained the highest concentrations of total capsaicinoids.     

A reflection on four impactful Ambio papers: The biotic perspective: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Climate change impacts

Climate change represents one of the most pressing societal and scientific challenges of our time. While much of the current research on climate change focuses on future prediction, some of the strongest signals of warming can already be seen in Arctic and alpine areas, where temperatures are rising faster than the global average, and in the oceans, where the combination of rising temperatures and acidification due to increased CO₂ concentrations has had catastrophic consequences for sensitive marine organisms inhabiting coral reefs. The scientific papers highlighted as part of this anniversary issue represent some of the most impactful advances in our understanding of the consequences of anthropogenic climate change. Here, we reflect on the legacy of these papers from the biotic perspective.     

Simulation of the flow of an explosive atmosphere exposed to a hot surface

The accidental ignition of combustible atmospheres by hot surfaces is of great concern for chemical and process plant safety. In this paper, we present our research regarding the evolution of thermal plumes originating from hot hemispheres and discs. In particular, we focus on the effect of the orientation of the surface on the ignition process. The auto-ignition temperatures and ignition locations were studied experimentally. To get further insight, we conducted detailed numerical simulations and validated them with measurements. Three-dimensional simulations were performed on hot hemispheres and hot discs for different orientations ranging from 0° to 180°. The solver employs a transient, implicit scheme which is based on the coupled heat transfer and flow equations. The mesh in the vicinity of the hot surfaces is refined to resolve the steep temperature gradients and to capture the boundary layer separation. The influence of the orientation on critical hot spots in the gas mixture is analysed by examining the flow structures and the temperature evolution of the buoyancy-driven flow. Using the obtained results, we discuss the change of the onset and location of the ignition.     

Small scale boilover and visualization of hot zone

Experimental studies of boilover were conducted in small scale rig at Universiti Teknologi PETRONAS (UTP), Malaysia and Loughborough University, United Kingdom. The study at UTP was aimed to demonstrate the ability of conducting tests at a smaller scale to simulate the boilover phenomenon. At Loughborough University, a novel laboratory scale rig was designed and built in order to obtain visual records of fuels' behaviour in a pool fire. The ultimate objective of these studies is to develop a greater understanding of boilover pertaining to fires involving the contents of storage tanks. Fuel mixtures containing light and heavy components were burnt as to study the feasibility of reproducing hot zone formation and boilover in a smaller scale and a safe environment. Boilover occurred after certain period of burning. It is found that thickness of the hot zone changed with time. It is also found that the time needed to start boilover increased when fuel thickness increased. The visualization of the fuel behaviour during the experiments was obtained to better understand the formation and growth of hot zone, the boiling of water layer and hence the boilover occurrence. Based on the data analysis and the photographs recorded from the experiments, the laboratory scale experimental rig could be used to simulate the hot zone formation mechanism and the boilover event safely and successfully. Such information are important for the understanding towards boilover phenomenon.     

TURBIDITY SUSPENI)ED SEDIMENT,AND WATER CLARITY: A REVIEW1

ABSTRACT: Suspended sediment causes a range of environmental damage, including benthic smothering, irritation of fish gills, and transport of sorbed contaminants. Much of the impact, while sediment remains suspended, is related to its light attenuation, which reduces visual range in water and light availability for photosynthesis. Thus measurement of the optical attributes of suspended matter in many instances is more relevant than measurement of its mass concentration. Nephelometric turbidity, an index of light scattering by suspended particles, has been widely used as a simple, cheap, instrumental surrogate for suspended sediment, that also relates more directly than mass concentration to optical effects of suspended matter. However, turbidity is only a relative measure of scattering (versus arbitrary standards) that has no intrinsic environmental relevance until calibrated to a ‘proper’ scientific quantity. Visual clarity (measured as Secchi or black disc visibility) is a preferred optical quantity with immediate environmental relevance to aesthetics, contact recreation, and fish habitat. Contrary to common perception, visual clarity measurement is not particularly subjective and is more precise than turbidity measurement. Black disc visibility is inter‐convertible with beam attenuation, a fundamental optical quantity that can be monitored continuously by beam transmissometry. Visual clarity or beam attenuation should supplant nephelometric turbidity in many water quality applications, including environmental standards.     

清洁检修机泵的改造方法

解体维修蜡油重油机泵时的放空浪费及拆卸现场的污染问题一直无法解决。南常减压装置2001年防腐扩能改造时，增设了热柴油冲洗机泵系统。旨在改善作业环境、减少浪费、杜绝污染。通过1年多的实施，取得了良好的使用效果。     

Dental fluorosis associated with drinking water from hot springs in Choma district in southern province,Zambia

This study was conducted to investigate the high incidence of mottled teeth among residents of an area with hot springs in the Choma District of the Southern Province of Zambia. A survey involving 128 pupils was conducted at a Basic School to collect data on pupil’s backgrounds and their main sources of drinking water between birth and age 7. A dental specialist examined the pupils’ teeth and samples of drinking water were collected from locations where the majority of the pupils lived. It was analysed for fluorides and other drinking water quality parameters. Results of the survey showed a highly significant (P < 0.001) association between pupils’ main sources of drinking water between birth and age 7 and the incidence of discoloured teeth. All (100%) pupils who drank water from hot springs before age 7 had moderate to severe fluorosis, while the majority (96.7%) of the pupils who drank water from other sources had no dental fluorosis. Fluoride concentrations ranged from 5.95 to 10.09 mg/l in water from hot springs, and from 0.03 to 0.6 mg/l in water from other sources. Fluoride levels in water from hot spring water samples exceeded the 1.5 mg/l WHO guideline value for drinking water, while those in water from other sources were significantly (P < 0.05) lower than this. We conclude that the high prevalence of mottled teeth among residents of the study area is a case of endemic dental fluorosis associated with drinking water from hot springs containing high concentrations of fluoride.     

丙酮法和热乙醇法测定浮游植物叶绿素a的方法比对

将丙酮法和热乙醇法用于测定浮游植物叶绿素a,分析水样中是否加入碳酸镁、水样体积、萃取时间、萃取剂、破碎方法、离心时间、水样存放时间和滤膜样品存放时间等8个因素对测定的影响,并确定最佳试验条件。结果表明:2种方法的测定值之间有较好的线性关系,相比丙酮法,热乙醇法更具优势。     

热油泵房火灾事故分析及控制

运用事故树分析法,对炼化企业高温泵房火灾的原因进行分析,并提出预防措施.     

Consumer reflections on the usage of plastic bags to parcel hot edible items: an empirical study in Malaysia

The packaging industry offers a wide range of pouching products to their clients in the food and beverage industries, healthcare industries and households as well. It is observed that pouching products are widely used and seemingly making them indispensable. Such practices are commonly found in Malaysia especially to parcel hot or cold food. The use of pouches raises two concerns namely solid waste disposal and food safety. The present study found more than 62% of the consumers purchase hot edible items in plastic bags daily or weekly because of its cost effectiveness and storage convenience. Consumers apparently are unperturbed by public campaigns against the use of plastic bags and neither do government regulations have any influence to reduce the use of plastic bags to parcel hot edible items. On the other hand, consumers are optimistic that the environmental and health hazards from the use of plastic bags to store hot edible items would only see a positive impact in the future.