An Asymmetric Nanoscale SOI MOSFET by Means of a P-N Structure as Virtual Hole’s Well at the Source Side

Silicon - This paper suggests and investigates a p-n structure, which emulates as a MOSFET. In the proposed structure we utilize an L-shape contact with a proper work function over the source...     

Validation of a Simple Spectrophotometric Method for the Measurement of Quaternary Ammonium Compound Residue Concentrations in Food Production Facility

Quaternary ammonium compound (QAC) residues can increase with each application and build up over a period of time during sanitation of food plants. Therefore, it is crucial to establish a simple but accurate method for routine measurement of QAC residues in food plants. In this study, a spectrophotometric method was validated and applied for the quantification of QAC residues on stainless steel surfaces. This method was based on the formation of a colored ion pair between the quaternary ions and Eosin-Y in the presence of Triton X-100. QAC residues were recovered from surfaces using swabs and were subsequently sonicated, and the isolated extracts were analyzed with a spectrophotometer (535 nm). The method was shown to be selective in the presence of interfering substances, and a linear relationship between the absorbance and concentration of QACs was detected in the concentration range from 0.5 to 10 mg?L^?1 (r ²?>?0.99). The limit of detection and limit of quantitation were 0.53 and 1.77 mg?L^?1, respectively. Satisfactory accuracy (93–97 %) and precision (relative standard deviation (RSD)?<?2.7 %) were obtained for the method. Assessment of the effect of swabbing protocol on the recovery, repeatability and intermediate precision of the method revealed that the mean recovery of residues was 90 %. Moreover, the percent RSD was less than 8.8 and 9.4 % for repeatability and intermediate precision, respectively. QAC residues were found to be stable on stainless steel surfaces for at least 6 days following deposition, a treatment that could be a potential risk especially in dry cleaning processes.     

The combination effects of trivalent gold ions and gold nanoparticles with different antibiotics against resistant Pseudomonas aeruginosa

Despite much success in drug design and development, Pseudomonas aeruginosa is still considered as one of the most problematic bacteria due to its ability to develop mutational resistance against a variety of antibiotics. In search for new strategies to enhance antibacterial activity of antibiotics, in this work, the combination effect of gold materials including trivalent gold ions (Au³⁺) and gold nanoparticles (Au NPs) with 14 different antibiotics was investigated against the clinical isolates of P. aeruginosa, Staphylococcus aureus and Escherichia coli. Disk diffusion assay was carried out, and test strains were treated with the sub-inhibitory contents of gold nanomaterial. Results showed that Au NPs did not increase the antibacterial effect of antibiotics at tested concentration (40 μg/disc). However, the susceptibility of resistant P. aeruginosa increased in the presence of Au³⁺ and methicillin, erythromycin, vancomycin, penicillin G, clindamycin and nalidixic acid, up to 147 %. As an individual experiment, the same group of antibiotics was tested for their activity against clinical isolates of S. aureus, E. coli and a different resistant strain of P. aeruginosa in the presence of sub-inhibitory contents of Au³⁺, where Au³⁺ increased the susceptibility of test strains to methicillin, erythromycin, vancomycin, penicillin G, clindamycin and nalidixic acid. Our finding suggested that using the combination of sub-inhibitory concentrations of Au³⁺ and methicillin, erythromycin, nalidixic acid or vancomycin may be a promising new strategy for the treatment of highly resistant P. aeruginosa infections.     

Antioxidant Property,Thymoquinone Content and Chemical Characteristics of Different Extracts from Nigella sativa L. Seeds

In this study, Nigella sativa L. seeds were extracted using supercritical carbon dioxide (SC-CO₂) and Soxhlet. Chemical characteristics, fatty acid composition, antioxidant activity and thymoquinone content of N. sativa L. extracts obtained through different methods were investigated and compared. It was revealed that antioxidant activity and thymoquinone content could be significantly different for SC-CO₂ and Soxhlet extracts. The results for fatty acid composition indicated that linoleic acid, palmitic acid and oleic acid were the main fatty acids in both extracts. The SC-CO₂ extraction could provide an extract with higher quality and antioxidant activity compared to Soxhlet extraction method and can be considered a more appropriate method for attaining a high-quality extract.     

Multi-Objective Optimization of Fusegates System under Hydrologic Uncertainties

Fusegates are independent units held only by the gravity installed on the free spillway of existing dams in order to increase reservoir storage and/or discharge capacity. Increasing reservoir storage in many dams can partly sacrifice dam’s reliabilities. So considering the failure risk of a dam together with the amount of increase in the reservoir capacity can prevent selecting fusegates which seriously endanger a dam safety. However, Lack of accurate information on various damage functions and difficulty in quantifying failure consequences are among principal limitations that hinder practical application of conventional approaches which account failure risk in real world hydrosystems problems. This study develops two effective multi-objective frameworks to optimize fusegates’ configuration in order to eliminate the need for such hard-to-get mathematical damage functions and provide valuable information on the failure risk, total cost, and increased water volume of a reservoir. The proposed models find trade-off solutions between two sets of conflicting objectives. The first competing objectives is investment cost and water storage and the second conflicting goals are water storage and failure probability under the inherent and parameter hydrologic uncertainties. Complicated flood routing phenomenon within a reservoir equipped with fusegates is explicitly taken into account to attain a more cost-effective and reliable design without jeopardizing the dam safety. Applicability and performance of the developed optimization schemes are discussed and demonstrated on a real life case study. The multi-objective optimization results represented as an ensemble of diverse trade-off solutions provide decision makers with more insight and understanding of system behavior and different design alternatives.     

Rapid Analysis of Styrene in Drinking Water and Tea Samples Using Dispersive Liquid-Liquid Microextraction Combined with Liquid Chromatography-Ultraviolet Detection

In this project, a simple, low-cost and rapid procedure based on dispersive liquid–liquid microextraction (DLLME) technique coupled with high performance liquid chromatography-ultraviolet detector (HPLC-UV) has been used for the extraction and determination of styrene in aqueous solutions. Several factors, such as type of extraction and dispersive solvents and their volumes, salt addition, and pH were optimized. Under optimal conditions, the recoveries of styrene for tea and water samples spiked with 10 and 15 ng mL^?1 were in the range of 91.4–97.8 %, whereas the temperature was set at 0, 4, 20, 70 and 91 °C for 15, 30, 60, 1440, and 14,400 min. The linear range was obtained in the interval of 1.86–50 ng mL^?1. The limits of detection (S/N = 3) and quantitation (S/N = 10) were 0.6 and 1.86 ng mL^?1, respectively. The relative standard deviations (RSDs) for three replicated analysis of styrene in aqueous samples ranged from 0.01 to 0.3 %.     

Characterization of Iranian Virgin Olive Oil from the Roodbar Region: A Study on Zard,Mari and Phishomi

The aim of this study is to describe the physicochemical properties of Iranian virgin olive oil (Zard, Mari and Phishomi) cultivated in Roodbar, Gilan. There were statistically significant differences for most of the parameters (P < 0.05). The acidity and peroxide value were in the limit established for classification as extra virgin olive oil. The oil of Zard had the highest amount of monounsaturated fatty acids followed by Mari and Phishomi oils. Mari oil proved to have the minimum value of polyunsaturated fatty acids, and the highest amount of phenolic compounds and oxidative stability. The oil of Phishomi had the maximum amount of chlorophylls and carotenoids and therefore it had the highest color index. There were no significant differences between the cultivars regarding the refractive index (1.469 at 20 °C for all three cultivars). According to the high content of monounsaturated fatty acids, the lowest amounts of polyunsaturated fatty acids and the highest amounts of phenolic compounds as well as the results of a Rancimat assay, it seems that the quality of the oil of Mari cultivar is better than Zard and Phishomi oils and is also more stable against oxidation.     

Experimental methods in chemical engineering: Rheometry

Rheometry is an experimental technique that measures the relationship between stresses, strains, and their derivatives of fluids and deformable materials. Capillary and Couette viscometers were among the first instruments used to study rheology but now sophisticated shear and extensional rheometers are widely available for quality control, research, and product development. Here, we introduce the basics of rheology, define material functions, and describe conventional instruments, physical principles, applications, and uncertainties. In 2016 and 2017, the Web of Science indexed 8400 articles that mention rheometry and a bibliometric map assigned the keywords into five clusters of research: behaviour and viscosity, mechanical properties and morphology, rheological properties and microstructure, polymers and nano-particles, and visco-elastic properties and mixtures. Journal of Rheology, Construction Building Materials, Food Hydrocolloids, Soft Matter, Rheologica Acta, and Journal of Applied Polymer Science publish at least 80 articles per year that mention rheometry.     

The Impact of Modern Technologies on Molecular Diagnostic Success Rates,with a Focus on Inherited Retinal Dystrophy and Hearing Loss

The identification of pathogenic variants in monogenic diseases has been of interest to researchers and clinicians for several decades. However, for inherited diseases with extremely high genetic heterogeneity, such as hearing loss and retinal dystrophies, establishing a molecular diagnosis requires an enormous effort. In this review, we use these two genetic conditions as examples to describe the initial molecular genetic identification approaches, as performed since the early 90s, and subsequent improvements and refinements introduced over the years. Next, the history of DNA sequencing from conventional Sanger sequencing to high-throughput massive parallel sequencing, a.k.a. next-generation sequencing, is outlined, including their advantages and limitations and their impact on identifying the remaining genetic defects. Moreover, the development of recent technologies, also coined “third-generation” sequencing, is reviewed, which holds the promise to overcome these limitations. Furthermore, we outline the importance and complexity of variant interpretation in clinical diagnostic settings concerning the massive number of different variants identified by these methods. Finally, we briefly mention the development of novel approaches such as optical mapping and multiomics, which can help to further identify genetic defects in the near future.