Ebeam fabrication of silicon nanodome photovoltaic devices without metal catalyst contamination

In this paper, the fabrication of silicon nanodome solar cells on crystalline wafers is reported. Crystalline silicon was patterned by ebeam lithography to define the silicon nano pillars with diameter of 100 nm, 1 μm and 5 μm. Unlike conventional bottom up growth of silicon nanowire from gold (Au), our method is free from contaminant. Consequently, it is a valuable method to fully evaluate the effect of nanostructures on solar cell performances. The fabricated devices were characterized through scanning electron microscopy, absorption measurements, illuminated solar cell I–V characteristics and monochromatic incident photon-to-electron conversion efficiency.     

Impact of Milk Protein Type on the Viability and Storage Stability of Microencapsulated Lactobacillus acidophilus NCIMB 701748 Using Spray Drying

Three different milk proteins — skim milk powder (SMP), sodium caseinate (SC) and whey protein concentrate (WPC) — were tested for their ability to stabilize microencapsulated L. acidophilus produced using spray drying. Maltodextrin (MD) was used as the primary wall material in all samples, milk protein as the secondary wall material (7:3 MD/milk protein ratio) and the simple sugars, d-glucose and trehalose were used as tertiary wall materials (8:2:2 MD/protein/sugar ratio) combinations of all wall materials were tested for their ability to enhance the microbial and techno-functional stability of microencapsulated powders. Of the optional secondary wall materials, WPC improved L. acidophilus viability, up to 70 % during drying; SMP enhanced stability by up to 59 % and SC up to 6 %. Lactose and whey protein content enhanced thermoprotection; this is possibly due to their ability to depress the glass transition and melting temperatures and to release antioxidants. The resultant L. acidophilus powders were stored for 90 days at 4 °C, 25 °C and 35 °C and the loss of viability calculated. The highest survival rates were obtained at 4 °C, inactivation rates for storage were dependent on the carrier wall material and the SMP/d-glucose powders had the lowest inactivation rates (0.013 day^?1) whilst the highest was observed for the control containing only MD (0.041 day^?1) and the SC-based system (0.030 day^?1). Further increase in storage temperature (25 °C and 35 °C) was accompanied by increase of the inactivation rates of L. acidophilus that followed Arrhenius kinetics. In general, SMP-based formulations exhibited the highest temperature dependency whilst WPC the lowest. d-Glucose addition improved the storage stability of the probiotic powders although it was accompanied by an increase of the residual moisture, water activity and hygroscopicity, and a reduction of the glass transition temperature in the tested systems.     

Comparing droplet breakup for a high-pressure valve homogeniser and a Microfluidizer for the potential production of food-grade nanoemulsions

A comparison of the emulsification performance of a high-pressure valve homogeniser (HPH) and a Microfluidizer has been carried out for a range of different oil to aqueous phase viscosity ratios, emulsifier types, pressure drops and number of passes through the chambers. It has been shown that for the same pressure drop across the two chambers, similar droplet sizes are produced (after 5 passes). Differences in droplet size were observed after a single pass, with the HPH producing larger droplets with a wider distribution of sizes. This difference can be attributed to the design of the homogenisation chambers with the HPH producing a wide distribution of shearing forces, so all of the starting emulsion does not experience the maximum stresses at each pass. Droplet size has been shown to be independent of viscosity ratio (0.1–80) for both homogenisers indicating that breakup is occurring in turbulent flow. No effect of emulsifier was observed in the Microfluidizer with SDS, Tween 20 and sodium caseinate. However, with the HPH, the droplet size reached a limiting value after 2 passes with SDS while with Tween 20 and sodium caseinate 5 passes were required indicating that coalescence occurs in the HPH but this is more effectively eliminated by SDS.     

Stress and the single cell: intrapopulation diversity is a mechanism to ensure survival upon exposure to stress

The application of Artificial Neural Networks (ANN) in predictive microbiology is presented in this paper. This technique was used to build up a predictive model of the joint effect of NaCl concentration, pH level and storage temperature on kinetic parameters of the growth curve of Lactobacillus plantarum using ANN and Response Surface Model (RSM). Sigmoid functions were fitted to the data and kinetic parameters were estimated and used to build the models in which the independent variables were the factors mentioned above (NaCl, pH, temperature), and in some models, the values of the optical densities (OD) vs. time of the growth curve were also included in order to improve the error of estimation. The determination of the proper size of an ANN was the first step of the estimation. This study shows the usefulness of an ANN pruning methodology. The pruning of the network is a process consisting of removing unnecessary parameters (weights) and nodes during the training process of the network without losing its generalization capacity. The best architecture has been sought using genetic algorithms (GA) in conjunction with pruning algorithms and regularization methods in which the initial distribution of the parameters (weights) of the network is not uniform. The ANN model has been compared with the response surface model by means of the Standard Error of Prediction (SEP). The best values obtained were 14.04% of SEP for the growth rate and 14.84% for the lag estimation by the best ANN model, which were much better than those obtained by the RSM, 35.63% and 39.30%, respectively. These were very promising results that, in our opinion, open up an extremely important field of research.     

The water needs for LDV transportation in the United States

Concern over increased demand for petroleum, reliable fuel supply, and global climate change has resulted in the US government passing new Corporate Average Fuel Economy standards and a Renewable Fuels Standard. Consequently, the fuel mix for light duty vehicle (LDV) travel in the United States will change over the coming years. This paper explores the embodied water consumption and withdrawal associated with two projections for future fuel use in the US LDV sector. This analysis encompasses conventional and unconventional fossil fuels, corn ethanol, cellulosic ethanol, soy biodiesel, electricity, and hydrogen. The existing mandate in the US to blend ethanol into gasoline had effectively committed 3300 billion liters of irrigation water in 2005 (approximately 2.4% of US 2005 fresh water consumption) for producing fuel for LDVs. With current irrigation practices, fuel processing, and electricity generation, it is estimated that by 2030, approximately 14,000 billion liters of water per year will be consumed and 23,000–27,000 billion liters withdrawn to produce fuels used in LDVs. Irrigation for biofuels dominates projected water usage for LDV travel, but other fuels (coal to liquids, oil shale, and electricity via plug-in hybrid vehicles) will also contribute appreciably to future water consumption and withdrawal, especially on a regional basis.     

Dispersal and attenuation of trace contaminants downstream of the Ajka bauxite residue (red mud) depository failure, Hungary

This paper identifies the spatial extent of bauxite processing residue (red mud)-derived contaminants and modes of transport within the Marcal and Ra?ba river systems after the dike failure at Ajka, western Hungary. The geochemical signature of the red mud is apparent throughout the 3076 km2 Marcal system principally with elevated Al, V, As, and Mo. Elevated concentrations of Cr, Ga, and Ni are also observed within 2 km of the source areas in aqueous and particulate phases where hyperalkalinity (pH < 13.1) is apparent. Although the concentrations of some trace elements exceed aquatic life standards in waters (e.g., V, As) and fluvial sediments (As, Cr, Ni, V), the spatial extent of these is limited to the Torna Creek and part of the upper Marcal. Source samples show a bimodal particle size distribution (peaks at 0.7 and 1.3 μm) which lends the material to ready fluvial transport. Where elevated concentrations are found in fluvial sediments, sequential extraction suggests the bulk of the As, Cr, Ni, and V are associated with residual (aqua-regia/HF digest) phases and unlikely to be mobile in the environment. However, at some depositional hotspots, association of As, Cr, and V with weak acid-extractable phases is observed.     

Mild methods of processing cassava leaves to remove cyanogens and conserve key nutrients

Current methods for processing cassava leaves to remove cyanogens involve pounding followed by boiling in water or boiling intact leaves for 30 min or longer. Boiling in water rapidly removes cyanogens but also breaks down vitamins, proteins and S-containing amino acids, which are necessary to detoxify ingested cyanide. Two methods have been developed to remove cyanogens whilst conserving these key nutrients present in cassava leaves. The first method involves pounding leaves in a pestle and mortar for a minimum of 10 min until the leaves are well macerated, followed by washing the pounded leaves twice in twice their weight of water at ambient temperature, which reduces the total cyanide remaining to 8%. Two further washes reduce the total cyanide to 3%. The second method is to immerse cassava leaves in ten times their weight of water at 50 ± 3 °C for 2 h followed by one change of water and further immersion for 2 h at 50 °C which reduces the total cyanide remaining to 7%.     

Effects of electromyographic feedback on hypnotic susceptibility: More preliminary data.

Conducted a double-blind study with 12 undergraduate males to test the hypothesis that taped verbal relaxation instructions and response-contingent EMG feedback training would increase suggestibility or hypnotic susceptibility over that obtained with instructions and false or noncontingent feedback. Data appear to confirm the hypothesis. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imagery and integration in the recall of words.

Conducted 2 experiments with Canadian males (N = 71) to test the previous suggestion that the reason for imaginal facilitation of memory performance is that images aroused by discrete verbal stimuli can be integrated into complex images, with the result that (a) storage capacity requirements are reduced and (b) recall of 1 component of the image leads to effective redintegration of the rest. Hypothesis (b) was supported by the observation that cued recall of concrete-noun pairs was enhanced more under integrative than under separate imagery instructions. Hypothesis (a) was supported by the observation that, for word-number lists, recall of concrete words exceeded recall of abstract words, but not at the expense of the digits. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composition and content of flavonol glycosides in broccoli florets (Brassica olearacea) and their fate during cooking

The two main flavonol glycosides present in broccoli florets were identified as quercetin 3-O-sophoroside and kaempferol 3-O-sophoroside. Three minor glucosides of quercetin and kaempferol were also detected, namely isoquercitrin, kaempferol 3-O-glucoside and a kaempferol diglucoside. The sophorosides of quercetin and kaempferol were present in raw florets at a level of 65 mg kg⁻¹ and 166 mg kg⁻¹ fresh weight, respectively. The total content of quercetin and kaempferol glycosides expressed as aglycone was 43 and 94 μg g⁻¹ fresh weight, respectively, and these agree with other recently published data. During the cooking process only 14–28% of the individual glucosides were retained in the cooked tissue, the remainder being largely leached into the cooking water with only a small loss attributed to the formation of the respective aglycones. © 1998 SCI.