Thin film silicon solar cells by AIC on foreign substrates

This paper presents the fabrication of thin film crystalline silicon solar cells on foreign substrates like alumina, glass–ceramic (GC) and metallic foils (ferritic steel—FS) using seed layer approach, which employs aluminium induced crystallisation (AIC) of amorphous silicon. Effect of hydrogen content in a-Si:H precursor films on the AIC process has been studied and the results showed that defects in the AIC grown films increased with increase of hydrogen content. At the optimal thermal annealing conditions, the AIC grown poly-Si films showed an average grain size of 7.6, 26, and 8.1 μm for the films synthesised on alumina, GC, and FS, respectively. The grains were (1 0 0) oriented with a sharp Raman peak around 520 cm^?1. Similarly, n-type seed layers were also fabricated by over-doping of as-grown AIC layers using a highly phosphorus doped glass solution. The resistivity of as-grown films reduced from 8.4×10^?2 Ω cm (p-type) to 4.1×10^?4 Ω cm (n-type) after phosphorus diffusion. These seed layers of n-type/p-type were thickened to form an absorber layer by vapour phase epitaxy or solid phase epitaxy. The passivation step was applied before the heterojunction formation, while it was after in the case of homojunction. Open circuit voltage of the junctions showed a strong dependence on the hydrogenation temperature and microwave (μW) power of electron cyclotron resonance (ECR) plasma of hydrogen. Effective passivation was achieved at a μW power of 650 W and hydrogenation temperature of 400 °C. Higher values of solar conversion efficiencies of 5% and 2.9% were achieved for the n-type and p-type heterojunction cells, respectively fabricated on alumina substrates. The analysis of the results and limiting factors are discussed in detail.     

The beginnings of plasmomechanics: towards plasmonic strain sensors

This article exposes the beginnings of a new field which could be named as “plasmomechanics”. Plasmomechanics comes from the convergence between mechanics and plasmonics. Here we discuss a relatively recent topic whose technological aim is the development of plasmonic strain sensors. The idea is based on the ability to deduce Au nanoparticles (NPs) distance distributions from polarized optical extinction spectroscopy which could thus give access to material strains. Variations of interparticle distances distributions can indeed lead to variations of plasmonic coupling and thus to material color change as shown here experimentally and numerically for random Au NP assemblies deposited onto elastomer films.     

Effects of catechin-rich oil palm leaf extract on normal and hypertensive rats’ kidney and liver

Catechin-rich oil palm (Elaeis guineensis) leaf extract (OPLE) possesses good ex vivo vasodilation, antioxidant and cardiovascular properties. This study evaluated the beneficial or toxic effects of OPLE on the liver and kidneys of normal and hypertensive rats. The OPLE (500 mg/kg body weight) were administered orally to normal Wistar Kyoto rats, spontaneously hypertensive rats (SHR) and N-ω-nitro-l-arginine methyl ester (l-NAME)-induced NO-deficient hypertensive rats. The OPLE reduced hypertension in NO-deficient rats, but not in SHR. Hepatocytes or glomeruli injury and oxidative markers were high in hypertensive rats compared to normal rats, and they were reduced (p < 0.05) by OPLE supplementation, even when there was no blood pressure reduction. Unlike the hypertensive drug captopril, the OPLE showed no toxicity to normal rats. The dose reported is equivalent 0.5 g of catechins/day for humans or 2.5 cups of tea. The catechins are from an abundant alternative source for potential use as functional food.     

Low-cycle fatigue of welded joints: coupled initiation propagation model

This paper deals with the low-cycle fatigue (LCF) design of welded structures, the aim being the critical analysis of the rule used in the RCC-MR [Design and construction rules for mechanical components of FBR nuclear islands, AFCEN, 1993], for the design and construction of fast breeder reactors. The study takes into account the evolution of the material behavior laws and damage accumulation during the fatigue loading. The adopted model consists of analyzing separately the behavior and the damage evolutions. It allows us to determine the damage ratio corresponding to initiation and propagation of a significant crack in order to determine the life duration. This model suggests the existence of a threshold level of loading, above which micro-cracks initiate. The initiation fatigue life can then be neglected below the threshold level. This work shows also that the RCC-MR rules are valid below this threshold load level.     

Purification of carbon dioxide produced during the fermentative production of fodder yeast and ethyl alcohol by saccharomyces cerevisiae

The impurities present in carbon dioxide produced during the fermentative production of fodder yeast and ethyl alcohol by Saccharomyces cerevisiae were mainly acetaldehyde and butyraldehyde. 2,4-DNP reagent was sensitive to these impurities and they were precipitated as hydrazones. The soluble volatile organic compounds were completely removed in washers (I and II). The other impurities present in carbon dioxide were removed by treating the gas with potassium permanganate and activated charcoal to obtain pure gas. The system used in the purification of carbon dioxide in the factory was efficient when washing water was sufficient (2400 litres of running water/h) and the potassium permanganate solution was changed when it was exhausted.     

A tabu search heuristic for the single vehicle pickup and delivery problem with time windows

The single vehicle pickup and delivery problem with time windows is a generalization of the traveling salesman problem. In such a problem, a number of transportation requests have to be satisfied by one vehicle, each request having constraints to respect: a pickup at its origin and a delivery at its destination, and a time window at each location. The capacity of the vehicle has to be respected. The aim is to minimize the total distance traveled by the vehicle. A number of exact and approximate solution methods exists in the literature, but to the authors knowledge none of them make use of metaheuristics, still promising with other vehicle routing problems. In this paper we present tabu search and probabilistic tabu search. Results obtained on classical traveling salesman problems and a class of randomly generated instances indicate that our approach often produces optimal solutions in a relatively short execution time.     

Potential Effects of Sweet Potato (Ipomoea batatas) in Hyperglycemia and Dyslipidemia—A Systematic Review in Diabetic Retinopathy Context

Hyperglycemia is a condition with high glucose levels that may result in dyslipidemia. In severe cases, this alteration may lead to diabetic retinopathy. Numerous drugs have been approved by officials to treat these conditions, but usage of any synthetic drugs in the long term will result in unavoidable side effects such as kidney failure. Therefore, more emphasis is being placed on natural ingredients due to their bioavailability and absence of side effects. In regards to this claim, promising results have been witnessed in the usage of Ipomoea batatas (I. batatas) in treating the hyperglycemic and dyslipidemic condition. Thus, the aim of this paper is to conduct an overview of the reported effects of I. batatas focusing on in vitro and in vivo trials in reducing high glucose levels and regulating the dyslipidemic condition. A comprehensive literature search was performed using Scopus, Web of Science, Springer Nature, and PubMed databases to identify the potential articles on particular topics. The search query was accomplished based on the Boolean operators involving keywords such as (1) Beneficial effect OR healing OR intervention AND (2) sweet potato OR Ipomoea batatas OR traditional herb AND (3) blood glucose OR LDL OR lipid OR cholesterol OR dyslipidemia. Only articles published from 2011 onwards were selected for further analysis. This review includes the (1) method of intervention and the outcome (2) signaling mechanism involved (3) underlying mechanism of action, and the possible side effects observed based on the phytoconstiuents isolated. The comprehensive literature search retrieved a total of 2491 articles using the appropriate keywords. However, on the basis of the inclusion and exclusion criteria, only 23 articles were chosen for further review. The results from these articles indicate that I. batatas has proven to be effective in treating the hyperglycemic condition and is able to regulate dyslipidemia. Therefore, this systematic review summarizes the signaling mechanism, mechanism of action, and phytoconstituents responsible for those activities of I. batatas in treating hyperglycemic based on the in vitro and in vivo study.     

Optimization of Freeze Drying Conditions for Purified Pectinase from Mango (Mangifera indica cv. Chokanan) Peel

Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (-2.66, 62.66 mg/mL), Arabic gum (-1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05) effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved.     

Comparative study of the oxidative and physical stability of liposomal and nanoliposomal polyunsaturated fatty acids prepared with conventional and Mozafari methods

The relative oxidative stability of freshly prepared and stored liposomal and nanoliposomal systems of docosahexaenoic acid (DHA, 22:6 n−3) and eicosapentaenoic acid (EPA, 20:5 n−3) were investigated. The effects of organic solvents on the oxidative stability of liposomal polyunsaturated fatty acids (PUFAs) produced by two methods, the Bangham thin-film hydration (conventional rotary evaporation method and using organic solvents) and Mozafari (direct hydration and without using organic solvents) methods, were compared. The highest physicochemical stability was observed in PUFA liposomes prepared by the Mozafari method, followed by conventional liposomes and bulk PUFAs. There was no significant change in physicochemical stability during 10 months of cold storage (4 °C) in the dark. Moreover, the comparison between liposomes (>200 nm) and nanoliposomes (50–200 nm) revealed that the surface charge, physical stability and oxidative stability of liposomal PUFAs increased as the size of the liposomes decreased. The differences in the oxidative stability of PUFAs may be due to the protective effects of aqueous systems, which indicate the advantage of using non-organic solvent (water and CO₂) techniques in liposome manufacturing.