Progress on large area n‐type silicon solar cells with front laser doping and a rear emitter

We report on the progress of imec's n‐type passivated emitter, rear totally diffused rear junction silicon solar cells. Selective laser doping has been introduced in the flow, allowing the implementation of a shallow diffused front surface field and a reduction of the recombination current in the contact area. Simplifications have been implemented towards a more industrial annealing sequence, by replacing expensive forming gas annealing steps with a belt furnace annealing. By applying these improvements, together with an advanced texturing process and emitter passivation by atomic layer deposition of Al₂O₃, 22.5% efficient cells (three busbars) have been realized on commercial 156 · 156 mm² Czochralski‐Si. This result has been independently confirmed by ISE CalLab. Copyright © 2016 John Wiley & Sons, Ltd.     

Non-positive autoimmune responses against CYP2E1 in refrigeration mechanics exposed to halogenated hydrocarbons

The aim of the study was to determine if occupational exposure to hydrofluorocarbons (HFC) and hydrochlorofluorocarbons (HCFC) generates autoimmune responses against CYP2E1. HFCs and HCFCs have replaced the chlorofluorocarbons (CFC) in e.g. refrigeration installations and air-conditioning systems. During the substitution period, refrigeration mechanics reported symptoms like asthma, influenza-like reactions, and joint troubles. These symptoms resemble those of chronic inflammatory diseases with an autoimmune component. Since exposure to structurally similar chemicals, e.g. halothane, has previously been associated with autoimmune responses and diseases, autoimmunity among the refrigeration mechanics might hypothetically explain the reported inflammatory symptoms. Serum from 44 Swedish men, occupationally exposed to halogenated hydrocarbons, was screened for antibodies against CYP2E1 with enzyme-linked immunosorbent assay. Thirty of the workers had asthma, joint problems or influenza-like symptoms whereas 14 of them had no such symptoms. They were all selected from a cohort of 280 refrigeration mechanics. Unexposed, healthy, Swedish men (n=35) constituted control group. The study was approved by the Ethics Committee at Karolinska Institutet. No increase in autoantibodies against CYP2E1 was detected among the occupationally exposed workers as compared to the unexposed controls. Further, there was no difference in antibody titer between the exposed workers with symptoms and the exposed, asymtomatic workers or the unexposed controls. The present study does not completely exclude a connection between exposure and effect but makes the relation less likely at these exposure levels.     

Effect of different ventilation regimens on ewes' milk and Canestrato Pugliese cheese quality in summer

The influence of three different ventilation regimens on air pollution in sheep houses and on the quality of ewe milk and of Canestrato Pugliese cheese was investigated during the summer season. The experimental treatments were low ventilation regimen (VR=35 m3/h per ewe) split in 30-min ventilation cycles (LOV-30); moderate ventilation regimen (VR=70 m3/h per ewe) split in 30-min ventilation cycles (MOV-30); moderate ventilation regimen (VR=70 m3/h per ewe) split in 60-min ventilation cycles (MOV-60). The LOV-30 milk had higher microbial load and bulk milk somatic cell count (BMSCC) and resulted in a weaker casein matrix in the curd compared with the MOV-30 and MOV-60 treatments. At 45 d of ripening, the LOV-30 cheeses had a lower casein content and higher non-casein nitrogen (NCN) and water-soluble nitrogen (WSN) contents than the MOV-30 and MOV-60 cheeses. Urea-polyacrylamide gel electrophoresis (urea-PAGE) of the pH 4.6-soluble N extract showed that the MOV-60 cheeses had fewer bands derived from casein (CN) hydrolysis than the LOV-30 or MOV-30 cheeses, despite its having exhibited the highest plasmin (PL) activity levels. Our results suggest that the ventilation regimen is critical in dairy sheep housing for optimizing the hygienic quality of ewe milk and the proteolytic processes occurring in Canestrato Pugliese cheese during ripening.     

Resistant starch—An accessible fiber ingredient acceptable to the Western palate

Dietary fiber intakes in Western societies are concerningly low and do not reflect global recommended dietary fiber intakes for chronic disease prevention. Resistant starch (RS) is a fermentable dietary fiber that has attracted research interest. As an isolated ingredient, its fine particle size, relatively bland flavor, and white appearance may offer an appealing fiber source to the Western palate, accustomed to highly refined, processed grains. This review aims to provide a comprehensive insight into the current knowledge (classification, production methods, and characterization methods), health benefits, applications, and acceptability of RS. It further discusses the present market for commercially available RS ingredients and products containing ingredients high in RS. The literature currently highlights beneficial effects for dietary RS supplementation with respect to glucose metabolism, satiety, blood lipid profiles, and colonic health. An exploration of the market for commercial RS ingredients indicates a diverse range of products (from isolated RS2, RS3, and RS4) with numerous potential applications as partial or whole substitutes for traditional flour sources. They may increase the nutritional profile of a food product (e.g., by increasing the fiber content and lowering energy values) without significantly compromising its sensory and functional properties. Incorporating RS ingredients into staple food products (such as bread, pasta, and sweet baked goods) may thus offer an array of nutritional benefits to the consumer and a highly accessible functional ingredient to be greater exploited by the food industry.     

Structure-composition relationships of the Traditional Balsamic Vinegar close to jamming transition

The Traditional Balsamic Vinegar of Modena (TBVM), an Italian valuable specialty produced from cooked grape must becomes viscous through a long-ageing process. TBVM may undergo jamming transition which causes its depreciation. A liquid and jammed TBVM were investigated for their microstructure and elemental composition by coupling two non-destructive techniques, i.e. Environmental Scanning Electronic Microscopy (ESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The same samples were also analyzed for their molecular size distribution by Size Exclusion Chromatography (SEC) and their shear viscosity with a stress-controlled rheometer. TBVM in the jammed state behaved as a pseudoplastic fluid due to the presence of nitrogen-free polymers with a molecular size dispersion lower than a liquid TBVM, the latest showed the Newtonian flow behavior. TBVM solid particles detected close to jamming transition showed a C/O ratio of 2.5 (liquid TBVM) and 3.7 (jammed TBVM), thus much higher than the main TBVM constituents (glucose, fructose and acetic acid). The Fe and Mg content was higher and pH was lower in the jammed TBVM. It was hypothesized that jamming transition in TBVM was the result of the unbalance between two time-dependent phenomena, i.e. the increase of the bulk viscosity and the structure relaxation of nitrogen-free polymers.     

Hydrogen production by anaerobic co-digestion of rice straw and sewage sludge

In this study, the rich carbon content of rice straw and the high nitrogen content of sewage sludge make the straw a good potential substrate and the sludge a viable inoculum for biohydrogen production. Two treatment conditions for the sewage sludge (raw and heat-treated) were used in the present experiments. Batch test using a mixture of rice straw and sewage sludge were carried out to investigate the optimum carbon to nitrogen (C/N) ratio for effective biohydrogen production. The experimental results indicate that untreated sludge could be used as the inoculum for efficient hydrogen production when mixed with the appropriate proportion of rice straw. According to our results, biogas and hydrogen production in all raw sludge cases ramped up more quickly and also exhibited longer and higher hydrogen production in comparison with heat-treated cases. At the C/N ratio of 25 in untreated sludge, hydrogen production was 33% higher than heat-treated one. Additionally, under the same conditions, high and stable hydrogen content (58%) and the maximal hydrogen yield (0.74 mmol H₂/g-VS added straw) were obtained.     

Experimentelle Untersuchung des Abwälzverhaltens von Beveloidverzahnungen mit lokal angepassten Verzahnungsdaten entlang der Zahnbreite

Forschung im Ingenieurwesen - Zur Übertragung von Drehmoment und Drehzahl in beliebiger Achsanordnung eignen sich bei kleinem Achswinkel bis 30° Beveloidverzahnungen. Besonders...     

Digestive protection of probiotic Lacticaseibacillus rhamnosus in Ricotta cheese by monoglyceride structured emulsions

This research aimed at studying the potential use of monoglyceride (MG) structured emulsions (MSEs) as delivery and protective systems for probiotic bacteria in Ricotta cheese. To this purpose, a low-fat commercial Ricotta cheese was added with MSEs formulated with milk, as water phase, and sunflower oil (MSE-SO) or anhydrous milk fat (MSE-AMF), as lipid phase. A commercial whole milk Ricotta cheese (W-RC) was considered as reference. A probiotic Lacticaseibacillus rhamnosus strain was inoculated as free cells in W-RC or embedded into the MSEs and added to the low-fat Ricotta at the same reference fat content. After physico-chemical characterisation, L. rhamnosus viability and sample destructuring behaviour upon in vitro digestion were evaluated. At the end of in vitro digestion, both W-RC and sample containing MSE-SO were unable to protect cells. By contrast, sample with AMF ensured a sufficient probiotic viability, even after 14 days of storage at 4 °C. This result was attributed to system composition and structure. During the gastric phase, the presence of caseins and MG-AMF mixed structures induced the formation of clots, entrapping and protecting cells against the acidic pH of the stomach, as confirmed by confocal micrographs and particle size. During the intestinal phase, cell viability was guaranteed by the formation of mixed micelles promoted by MG. It was demonstrated that microbial cells located near MG structures where they found protection.     

VFC-SMOTE: very fast continuous synthetic minority oversampling for evolving data streams

Data Mining and Knowledge Discovery - The world is constantly changing, and so are the massive amount of data produced. However, only a few studies deal with online class imbalance learning that...     

Interlaboratory study on lipid oxidation during accelerated storage trials with rapeseed and sunflower oil analyzed by conjugated dienes as primary oxidation products

Accelerated storage tests are frequently used to assess the oxidative stability of foods and related systems due to its reproducibility. Various methods and experimental conditions are used to measure lipid oxidation. Differences between laboratories make it necessary to determine the repeatability and reproducibility of oxidation tests performed under the same conditions. The objective of the present interlaboratory study was to evaluate the outcome of a storage test for two different bulk oils, sunflower oil (SFO) and rapeseed oil (RSO), during a period of 9 weeks at 20°C, 30°C, 40°C, and 60°C. Sixteen laboratories were provided with bottled oils and conducted the storage tests according to a detailed protocol. Lipid oxidation was monitored by the formation of conjugated dienes (CD) and the activation energy (E_a) was determined for comparative purposes and statistically evaluated. An increase in CD formation was observed for both oils when the storage temperature was increased in all laboratories. The E_a,1 ranged from 47.9 to 73.3 kJ mol⁻¹ in RSO and from 27.8 to 62.6 kJ mol⁻¹ in SFO, with average values of 58.2 and 46.8 kJ mol⁻¹, respectively. The reproducibility coefficients were 10.9% and 18.2% for RSO and SFO, respectively. Practical applications: In order to compare results on oxidative stability of foods derived from different studies, the reproducibility of storage tests and methods employed to evaluate the oxidation level should be considered. This study provides fundamental data on the reproducibility of lipid oxidation under accelerated storage conditions and defines important parameters to be considered for the conduction of experiments.