Single nanoparticle detectors for biological applications

Nanoparticle research has become increasingly important in the context of bioscience and biotechnology. Practical use of nanoparticles in biology has significantly advanced our understanding about biological processes in the nanoscale as well as led to many novel diagnostic and therapeutic applications. Besides, synthetic and natural nanoparticles are of concern for their potential adverse effect on human health. Development of novel detection and characterization tools for nanoparticles will impact a broad range of disciplines in biological research from nanomedicine to nanotoxicology. In this article, we discuss the recent progress and future directions in the area of single nanoparticle detectors with an emphasis on their biological applications. A brief critical overview of electrical and mechanical detection techniques is given and a more in-depth discussion of label-free optical detection techniques is presented.     

Unified formulation for web crippling strength of cold-formed steel sheeting using stepwise regression

This study presents the availability of a stepwise regression (SR) method for the unified formulation of web crippling strength of cold-formed steel decks for various loading cases. Existing design codes offer different formulations for each loading case. However, the objective of this study is to provide an alternative unified (single) formulation to related design codes which can be used for all loading cases at the same time and should be more accurate than the separate formulations of existing design codes. The unified stepwise regression formulation is based on well established experimental results from the literature. The proposed unified SR formulation results are compared with experimental results and current design codes and found to be more accurate.     

Modelling a ground-coupled heat pump system using adaptive neuro-fuzzy inference systems

The aim of this study is to demonstrate the usefulness of an adaptive neuro-fuzzy inference system (ANFIS) for the modelling of ground-coupled heat pump (GCHP) system. The GCHP system connected to a test room with 16.24 m² floor area in Fırat University, Elazığ (38.41°N, 39.14°E), Turkey, was designed and constructed. The heating and cooling loads of the test room were 2.5 and 3.1 kW at design conditions, respectively. The system was commissioned in November 2002 and the performance tests have been carried out since then. The average performance coefficients of the system (COPS) for horizontal ground heat exchanger (GHE) in the different trenches, at 1 and 2 m depths, were obtained to be 2.92 and 3.2, respectively. Experimental performances were performed to verify the results from the ANFIS approach. In order to achieve the optimal result, several computer simulations have been carried out with different membership functions and various number of membership functions. The most suitable membership function and number of membership functions are found as Gauss and 2, respectively. For this number level, after the training, it is found that root-mean squared (RMS) value is 0.0047, and absolute fraction of variance (R²) value is 0.9999 and coefficient of variation in percent (cov) value is 0.1363. This paper shows that the values predicted with the ANFIS, especially with the hybrid learning algorithm, can be used to predict the performance of the GCHP system quite accurately.     

Children at risk: predictors of car safety seat misuse in Ontario

When used correctly, child safety seats can reduce the risk of death and serious injury by 54% in toddlers and 71% in infants [National Highway Traffic Safety Administration (NHTSA), 2001. Traffic Safety Facts 2001. Children (DOT HS 809 471), U.S. Department of Transportation, Washington, DC]. The purpose of this study was to identify factors that predict correct use of car safety seats. The study was conducted in a large urban area in Southwestern Ontario and a small urban and rural area in Northern Ontario. Participants were 1263 caregivers who completed a self-report survey on their knowledge and use of car safety seats for their children (N=2199). Logistic regression analysis revealed that female caregivers, caregivers with higher levels of education, and caregivers who reported that finding information about the correct use of child safety seats was "difficult" were more likely to report correctly using car safety seats. The results also showed that children aged 7 months to 8 years old had substantially lower odds of being in the correct car safety seat compared to children aged 6 months or younger, or children aged 9 years or older. The high risk nature of misuse of child seats for infants and younger children may be an important cue to action for health professionals to develop comprehensive prevention strategies.     

Fatty acids of neutral and phospholipids of three endangered trout: Salmo trutta caspius Kessler, Salmo trutta labrax Pallas and Salmo trutta macrostigma Dumeril

Total (TL), neutral (NL) and phospholipid (PL) amounts and fatty acid (FA) composition of female Salmo trutta caspius, Salmo trutta labrax and Salmo trutta macrostigma were investigated during one year. Twenty-three FAs were identified in both NLs and PLs. The principal FAs of both fractions were palmitic acid in saturated fatty acid, oleic acid in monounsaturated fatty acid, docosahexaenoic acid (DHA) in n-3 polyunsaturated fatty acids (n-3 PUFAs) and linoleic acid in n-6 PUFAs. The highest values for TLs, NLs and PLs were found in winter. As a general trend, the highest n-3/n-6 ratios and eicosapentaenoic acid (EPA) + DHA amounts were found in the winter and this coincided with the lowest gonado-somatic index.     

Injection of biosurfactant and chemical surfactant following hot water injection to enhance heavy oil recovery

This study investigates the potential of enhancing oil recovery from a Middle East heavy oil field via hot water injection followed by injection of a chemical surfactant and/or a biosurfactant produced by a Bacillus subtilis strain which was isolated from oil-contaminated soil. The results reveal that the biosurfactant and the chemical surfactant reduced the residual oil saturation after a hot water flood. Moreover, it was found that the performance of the biosurfactant increased by mixing it with the chemical surfactant. It is expected that the structure of the biosurfactant used in this study was changed when mixed with the chemical surfactant as a probable synergetic effect of biosurfactant-chemical surfactants was observed on enhancing oil recovery, when used as a mixture, rather than alone. This work proved that it is more feasible to inject the biosurfactant as a blend with the chemical surfactant, at the tertiary recovery stage. This might be attributed to the fact that in the secondary mode, improvement of the macroscopic sweep efficiency is important, whereas in the tertiary recovery mode, the microscopic sweep efficiency matters mainly and it is improved by the biosurfactant-chemical surfactant mixture. Also as evidenced by this study, the biosurfactant worked better than the chemical surfactant in reducing the residual heavy oil saturation after a hot water flood.