Sources, concentrations, and risks of naphthalene in indoor and outdoor air

Naphthalene is a ubiquitous pollutant, and very high concentrations are sometimes encountered indoors when this chemical is used as a pest repellent or deodorant. This study describes the distribution and sources of vapor-phase naphthalene concentrations in four communities in southeast Michigan, USA. Outdoors, naphthalene was measured in the communities and at a near-road site. Indoors, naphthalene levels were characterized in 288 suburban and urban homes. The median outdoor concentration was 0.15 μg/m(3), and a modest contribution from rush-hour traffic was noted. The median indoor long-term concentration was 0.89 μg/m(3), but concentrations were extremely skewed and 14% of homes exceeded 3 μg/m(3), the chronic reference concentration for non-cancer effects, 8% exceeded 10 μg/m(3), and levels reached 200 μg/m(3). The typical excess individual lifetime cancer risk was about 10(-4) and reached 10(-2) in some homes. Important sources include naphthalene's use as a pest repellent and deodorant, migration from attached garages and, to lesser extents, cigarette smoke and vehicle emissions. Excessive use as a repellent caused the highest concentrations. Naphthalene presents high risks in a subset of homes, and policies and actions to reduce exposures, for example, sales bans or restrictions, improved labeling, and consumer education, should be considered. PRACTICAL IMPLICATIONS: Long-term average concentrations of naphthalene in most homes fell into the 0.2-1.7 μg/m(3) range reported as representative in earlier studies. The highly skewed distribution of concentrations results in a subset of homes with elevated concentrations and health risks that greatly exceed US EPA and World Health Organization (WHO) guidelines. The most important indoor source is the use of naphthalene as a pest repellant or deodorant; secondary sources include presence of an attached garage, cigarette smoking, and outdoor sources. House-to-house variation was large, reflecting differences among the residences and naphthalene use practices. Stronger policies and educational efforts are needed to eliminate or modify indoor usage practices of this chemical.     

Data sampling and processing for contact free-form surface scan-tracking measurement

To overcome the shortcomings of the traditional free-form surface tracking measurement data sampling methods, a new data accept and reject method which combines isochronous indistinctive sampling with off-line equal-error accurate arithmetic is designed. Dual-thread and dual-buffer dynamic storage technique is adopted to solve the problem of mass data information storage, and data acquisition processing is divided into two links: data sampling thread and data storage thread, each link being achieved by an individual thread and can concurrently assess data buffer without overlapping. SQLite3 is chosen to realize data storage, and the storage speed is tested by experiments. To reflect the geometric characteristic of the model surface figure accurately and make the measured data close to the real model curve more, the circle ratio method is utilized to achieve the curve smoothing treatment. The designed data sampling method enhances the sampling precision and sampling efficiency. Finally, a bicycle saddle model intersection’s self-learning control process is simulated with Matlab. Simulation results demonstrate the workability and the effectiveness of the proposed method.     

One-step synthesis of highly biocompatible multi-shaped gold nanostructures with fruit extract

In this study, the authors demonstrate the synthesis of various gold nanostructures through a one-step, green and complete bio-modulation approach. Nanoparticles were successfully synthesised by the addition of gold aqueous solution to fruit extracts, including orange, papaya, peach or lemon. The particles were of various shapes and sizes with high abundance, such as sphere, marigold, triangle and hexagon. The biocompatibility of the presented gold nanostructures was examined; haemolysis tests revealed a non-toxicity result in blood cell uptake of such gold nanostructures. This study opens the exciting possibility of synthesising various multi-shaped nanoparticles through a simple and green approach, as well as paving the way for future bio-applications.     

Physical and Sensory Properties of Model Foods Supplemented with Cauliflower Fiber

Cauliflower floret/curd and stem, as by-products of processing, are a source of pectic-polysaccharide-rich fiber concentrates for use as water and oil binding agents and textural agents to improve the properties of model foods. Dehydration resulted in a 10% decrease in methyl esterification at above 40°C. Water retention capacity of florets (40°C) was reduced from 12.8 g/g to 5.7 g/g in 75°C dried samples, demonstrating the importance of matrix structure rather than polysaccharide composition for functional properties. Incorporation gave a 10% increase in the yield of beefburgers and a partial substitution for purified gums in sauces. Cauliflower fibers can be incorporated into food systems at concentrations found in vegetables but sensory characteristics depend on processing history.     

Thermal resistance of Salmonella serovars isolated from raw, frozen chicken nuggets/strips, nugget meat and pelleted broiler feed

Raw, frozen chicken nuggets/strips available at retail and prepared at home before consumption have been identified as a significant risk factor in contracting food-borne salmonellosis. Cases of salmonellosis from consumption of these products may be due, in part, to Salmonella strains originating in broiler feed. In this study the thermal resistances of Salmonella strains isolated from chicken nuggets and strips, chicken nugget/strip meat and broiler feed were determined to assess whether they exhibited enhanced thermal resistance. Thermal resistances (D- and z- values) of 7 cocktails (25 isolates, 4 serovars) were determined in commercially prepared irradiation-treated chicken nugget/strip meat blend, and heated in a constant temperature waterbath. The thermal resistances found were lower than those reported for similar strains in the literature. D-values ranged from 6.93 to 0.12 min at 55 and 62 degrees C respectively, with z-values from 4.10 to 5.17 degrees C. Two strains of S. Enteritidis separately isolated from pelleted feed and chicken nugget meat blend, with indistinguishable geno- and phenotypes, had lower (and probably identical) thermal resistances than the other isolates. Results indicated that the strains of Salmonella isolated from raw, frozen chicken nuggets/strips and pelleted broiler feed did not exhibit unusually high thermal resistance, and that normal heating (71 degrees C) prior to consumption should eliminate these organisms from chicken nuggets/strips.     

Etude des conditions de formation par voie hydrothermale des borates de terres rares TBO3 pseudo-vaterite

The pseudo-vaterite structure of the rare-earths-metals (Lu to Sm) is unique with no analogy among nitrates and carbonates. A careful study by hydrothermal synthesis of the conditions of formation of these compounds gives useful informations on the crystallographic structure and allows to synthetize three new pseudo-vaterite compounds, NdBO₃, PrBO₃, CeBO₃.     

磷光WOLED——光明之路

平板电视屏幕尺寸不断地增长，它的照明功耗也在不断增加。而发白光的有机电致发光器件可以实现平板电视低功耗全彩色光源的要求，并且还可以应用于其他固态照明设施。     

Genetic Algorithms for Vehicle Dispatching

Decisions regarding the dispatch of transportation vehicles for servicing customer requests is mostly based on human expertise. In this paper, genetic algorithms are proposed as a means to support vehicle dispatchers in the context of a courier or express mail service. Vehicle dispatching is first modeled as a multiattribute choice problem. Then, a genetic algorithm is used to find a weighting scheme for the attributes that best reproduces the expert's decision process. Numerical results are reported on data collected from an operations day of a courier service company.     

Predicted risk of childhood allergy, asthma, and reported symptoms using measured phthalate exposure in dust and urine

The associated risk of phthalate exposure, both parent compounds in the home and their metabolites in urine, to childhood allergic and respiratory morbidity, after adjusting for exposures of indoor pollutants, especially bioaerosols, was comprehensively assessed. Levels of five phthalates in settled dust from the homes of 101 children (3-9 years old) were measured, along with their corresponding urinary metabolites. Other environmental risk factors, including indoor CO2, PM2.5, formaldehyde, 1,3-β-D-glucan, endotoxin, allergen and fungal levels, were concomitantly examined. Subject's health status was verified by pediatricians, and parents recorded observed daily symptoms of their children for the week that the home investigation visit took place. Significantly increased level of benzylbutyl phthalate, in settled dust, was associated with test case subjects (allergic or asthmatic children). Higher levels of dibutyl phthalate and its metabolites, mono-n-butyl phthalate, and mono-2-ethylhexyl phthalate were found to be the potential risk factors for the health outcomes of interest. Similarly, indoor fungal exposure remained a significant risk factor, especially for reported respiratory symptoms. The relative contribution from exposure to phthalates and indoor biocontaminants in childhood allergic and respiratory morbidity is, for the first time, quantitatively assessed and characterized. PRACTICAL IMPLICATIONS: For asthmatic and allergic children living in subtropical and highly developed environments like homes in Taiwan, controlling environmental exposure of phthalates may be viewed as equally important as avoiding indoor microbial burdens, for the management of allergy-related diseases. It is also recognized that multidisciplinary efforts will be critical in realizing the true underlying mechanisms associated with these observations.