Effect of Gaseous Ozone on Papaya Anthracnose

Anthracnose caused by the fungus Colletotrichum gloeosporioides is considered as one of the most devastating postharvest disease of papaya. The aim of this study was to evaluate the effectiveness of gaseous ozone as a potential antifungal preservation technique to overcome anthracnose disease of papaya during cold storage. Different concentrations of ozone (0 (control), 0.04, 1.6, and 4 ppm) were applied for various exposure durations (48, 96, and 144 h). Radial mycelia growth and conidial germination were evaluated in vitro after fungal exposure to the different levels and durations of ozone. Significant inhibition in radial mycelia growth of C. gloeosporioides was observed (p?<?0.05) in all ozone treatments as compared to the control during 8 days of incubation at room temperature (25?±?3 °C). Ozone treatment of papaya fruit with 1.6-ppm ozone for 96 h delayed and simultaneously decreased the disease incidence to 40 % whereas disease severity was rated at 1.7, following 28 days of storage at 12?±?1 °C and 80 % relative humidity. The scanning electron microscopy showed that 4-ppm ozone caused disintegration of spore structure and did not affect the cuticular surface of fruit. Thus, ozone fumigation can reduce postharvest losses of papaya caused by anthracnose.     

Well-width dependence of the phase coherent photorefractive effect in ZnSe quantum wells

We report on the well-width dependence of the phase coherent photorefractive (PCP) effect in ZnSe/ZnMgSe single quantum wells (QWs) using 90 fs light pulses. The experiments are performed in a four-wave-mixing configuration at temperatures between 25 and 65 K. The ZnMgSe/ZnSe QWs with 10, 5 and 3 nm well width were grown on GaAs substrate using molecular beam epitaxy. With decreasing QW thickness we observe a reduction of the PCP diffraction efficiency. This is attributed to the higher electron energy in small QWs due to the quantum size effect, which leads to a reduced equilibrium density of captured electrons in the QW. With increasing temperature the PCP signal further decreases which is attributed to thermal activation of the QW electrons back to the GaAs substrate.     

Utilizing Accessible Heat Enhancing Cooling Effect with Three Bed Solar Adsorption Chiller

ABSTRACT

Conventional solar heat-driven single stage two bed chillers demand a large area for installation of solar thermal collector to activate the chiller, but in a highly populated tropical country open spaces is insufficient. In the intention to utilize accessible solar energy with better performance, a mathematical investigation is carried out with a three bed adsorption cooling unit working with silica gel-water pair. The studied chiller is powered by direct solar heat collected by a series of compound parabolic concentrator solar thermal collectors without any heat or mass recovery. The working principal of the chiller is, in principle, the same as the conventional two-bed adsorption chiller. However, instead of two half cycles, there are three one third cycles in the proposed chiller in which at every cycle the former desorber is kept in the precooling mode and as an adsorber for the next two one third cycles, respectively. As desorption kinetic is faster than the adsorption kinetics, this longer precooling mode helps the silica gel granules to adsorb more water molecules and increase evaporation rate. Hence, a better cooling effect of at least 1°C can be observed, increases chiller working hour after sunset for almost a further one hour.     

Utilizing the Explicit Finite Element Method for Studying Granular Flows

Granular flows are systems of complex dry particulates whose behavior is difficult to predict during sliding contact. Existing computational tools used to simulate granular flows are particle dynamics, cellular automata (CA), and continuum modeling. In the present investigation, another numerical tool—the explicit finite element method (FEM)—is analyzed as a potential technique for simulating granular flow. For this purpose, explicit dynamic finite element models of parallel shear cells were developed. These models contained 52 particles and consisted of granules that are both round and multi-shaped (diamond, triangle, and rectangle). Each parallel shear cell consisted of a smooth stationary top wall and a rough bottom surface that was given a prescribed velocity of U = 0.7 in/sec (1.78 cm/s). The coefficient of friction (COF) between the particle–particle and particle–wall collisions was varied between 0.0 and 0.75. Utilizing the output of the simulations, results are presented for the shear behavior, particle kinetic energy, and particle stresses within the shear cell as a function of time. As a means of validating the explicit technique for granular flow, a 75 particle, zero roughness, couette shear cell model (solid fraction of 0.50) is subsequently presented for which direct comparisons are made to the results published by Lun. [Lun, C.K. et al.: Phys. Fluids 8, 2868–2883 (1996)] Overall, the results indicate that the explicit FEM is a powerful tool for simulating granular flow phenomena in sliding contacts. In fact, the explicit method demonstrated several advantages over existing numerical techniques while providing equivalent accuracy to the molecular dynamics (MD) approach. These advantages included being able to monitor the collision (sub-surface and surface) stresses and kinetic energies of individual particles over time, the ability to analyze any particle shape, and the ability to capture force chains during granular flow.     

Increased height gain of children fed a high-protein diet during convalescence from shigellosis: a six-month follow-Up study

The impact of dietary supplementation on catch-up growth was evaluated in 69 malnourished children ages 24-60 mo after recovery from shigellosis. They were fed either a high-protein (HP) diet with 15% of energy as protein, or a standard-protein (SP) diet with 7.5% energy as protein, for 3 wk in a metabolic study ward. Children were followed up bi-weekly for 6 mo by trained health assistants when anthropometric measurements and information of any illness were collected. Thirty-one children in the HP group and 28 children in the SP group completed 6-mo follow-up. The increase in height (mean +/- SD) was 5.3 +/- 1.0 cm vs. 4.1 +/- 1.1 cm for HP and SP groups, respectively (P < 0.001), whereas increase in body weight was 1.39 +/- 0.58 and 1.29 +/- 0.72 kg for children fed HP and SP, respectively (P = 0.59). The proportion of children who were severely stunted (< -2 SD height-for-age) decreased from 45 to 29% in the HP group compared to 50 to 46% in the SP group (P < 0.05) at 6-mo follow-up. The number of diarrheal episodes per child tended to be lower in the HP vs. SP than in the SP group (1.9 vs. 2.3, P = 0.41). These results demonstrate that feeding an HP diet to the malnourished children during recovery from shigellosis enhanced linear growth with a modest reduction in diarrheal morbidity during the 6-mo follow-up period.     

A high glycemic index starch diet affects lipid storage-related enzymes in normal and to a lesser extent in diabetic rats

The of this study was to evaluate the chronic effects of a high (waxy corn) vs. a low (mung beans) glycemic index starch diet on the lipogenic enzymes, fatty acid synthase (FAS) and lipoprotein lipase (LPL). Normal and diabetic (streptozotocin-injected on d 2 of life) male Sprague-Dawley rats consumed a diet containing 575 g/kg carbohydrates either as waxy cornstarch (WCS) or as mung bean starch (MBS). After 3 wk, neither body weights nor relative epididymal fat pad weights differed. In diabetic rats, the WCS diet induced high basal plasma insulin levels. Plasma triglycerides were not significantly affected by diet in either normal or diabetic rats. Adipose tissue and liver LPL activities were not modified by the type of starch in the diet. In normal rats, FAS activity and gene expression in epididymal adipose tissue but not in liver were greater in rats consuming the WCS diet than in those consuming MBS. To evaluate the implication of insulin in this regulation, two genes regulated by insulin [GLUT4 and phosphoenolpyruvate carboxykinase (PEPCK)] were also studied. The high glycemic index WCS diet compared with the low glycemic index MBS diet resulted in lower hepatic PEPCK mRNA in both normal and diabetic rats. Normal, but not diabetic rats fed WCS had greater GLUT4 gene expression in adipocytes than did those fed MBS. We conclude that the total replacement of 575 g/kg low glycemic index starch by a high glycemic index starch for 3 wk caused the following in normal rats: 1) high FAS activity and mRNA in adipose tissue but not in liver and 2) high GLUT4 gene expression in adipose tissue. In both normal and diabetic rats this same diet resulted in lower hepatic PEPCK mRNA. Therefore, high glycemic index starch diet is implicated in stimulating FAS activity and lipogenesis and might have undesirable long-term metabolic effects.     

A simple process to produce a high quality silicon surface prior toselective epitaxial growth

A simple and low-cost process was devised to eliminate etch damage resulting from oxide etching on the seed-hole surface prior to selective epitaxial growth (SEG) of silicon. The process consists of a low power C ₂F₆ RIE step which was performed right after the oxide etch step in the same etch reactor. The use of this step excluded the need of a conventional sacrificial oxide to remove damaged silicon regions and residual polymers. The n-p diodes resulting from n-type SEG grown on p-type substrate were used to evaluate the quality of the silicon surface prior to SEG     

Chromosome instability and unusual features of some widely used strains of Candida albicans

Electrophoretic karyotyping of the Candida albicans revealed a different migration pattern of ChR in three different stocks of the sequencing strain SC5314. In one stock, the high instability of ChR size prevented the migration of ChR as a compact band; ChR appeared, instead, as a smear. In some stocks, ChR and/or Ch1 ploidy diminished, suggesting mixed populations of disomic and monosomic cells. Similarly, some stocks of widely used derivatives CAI4 and BWP17 contained smearing of ChR. In addition, the most manipulated strain in the lineage of SC5314, the last derivative, BWP17, acquired an increase in the size of Ch7b and revealed an unusual property. BWP17 did not tolerate a well-established procedure of telomere-mediated fragmentation of a chromosome; the remaining intact homologue always duplicated. We suggest that some stocks of SC5314 are unstable and that BWP17 may not be appropriate for general studies. Instead of BWP17 or CAI4, we recommend using for general research CAF4-2, which is a relatively stable Ura- derivative, and which has been successfully used for more than a decade in our laboratory.     

Synthesizing the note-specific atoms based on their fundamental frequency,used for single-channel musical source separation

The musical source separation deals with extracting the musical signals from a mixture. To attain this goal, one of the efficient methods is to decompose the mixture into a dictionary of some basic functions that inherently describe the instruments. Usually, a unique function is synthesized for each of the notes of each instrument, called the note-specific atom. In this paper, a sine-harmonic model is utilized to synthesize note-specific atoms and the note’s fundamental frequency is used as a prior information to determine the model parameters. To calculate these parameters, the training signal spectrum is processed only around the main note harmonics. Experimental results demonstrated that the proposed method is much faster in note-specific atoms synthesis, without decreasing the source separation quality and can also eliminate the single-frequency noise from training signals.

     

An efficient ontology-based topic-specific article recommendation model for best-fit reviewers

Scientometrics - In general peer review is accredited as the vital and utmost cornerstone of the scientific publishing and research developments. Undeniably, the reviewers play a decisive role in...