Izravna i neizravna sterilizacija mikroba plazmom

Atmospheric-pressure parallel-plate dielectric barrier discharge has been designed for sterilization of Saccharomyces Cerevisiae and Candida yeasts. Oxygen has been used as the input working gas. The output gas after discharge operation was a mixture of both ozone and oxygen, with concentration that depends on the applied voltage between the electrodes, gap space and gas flow rate. Sterilization process has been done in two ways, by direct exposure to oxygen plasma inside the discharge cell and by indirect exposure to the plasma. Survivor curves, and scanning and transmission electron microscope were used to study the inactivation kinetics and morphology of the yeast surface before and after sterilization. It has been found that the indirect sterilization causes yeast inactivation in a short time, less than three minutes, while the direct sterilization took place in a longer time, more than ten minutes.Sagradili smo posudu s usporednim pločama i dielektričnom pregradom za postizanje izboja na atmosferskom tlaku, namijenjenu za proučavanje sterilizacije mikroba Saccharomyces Cerevisiae i Candida. Radni plin bio je kisik. Izlazni plin iz posude bio je smjesa ozona i kisika, čija je koncentracija ovisna o vaponu izboja među elektrodama, procijepu i brzini protjecanja plina. Sterilizacija se provodila na dva načina, izravnim izlaganjem u izbojnoj posudi i neizravnim izlaganjem plazmi. Za proučavanje kinetike prekida aktivnosti stanične plazme i oblika mikrobne površine rabili smo krivulje preživjelih stanica prije i poslije sterilizacije. Ustanovili smo da neizravna sterilizacija dovodi do prekida aktivnosti mikroba u kratkom vremenu, manje od tri minute, dok je izravna sterilizacija trajala dulje, više od deset minuta

Biomimetic Potentials for Building Envelope Adaptation in Egypt

AbstractBiomimicry is a science that seeks sustainable solutions by emulating nature's time-tested 3.8 billion years of patterns and strategies. The paper is concerned with embodying the biomimetic strategies to building envelopes which shall offer a high potential to reduce the energy demand, save material and thus improve the sustainability of buildings, through accessing current practices process of natural ventilation biomimicry in buildings for a potential application in building envelope for environmental adaptation which could help for the emergence of a new generation of biomimetic building envelopes aiming at promoting biomimicry in Egypt by showing the benefits that could be harvested

Izravna i neizravna sterilizacija mikroba plazmom

Atmospheric-pressure parallel-plate dielectric barrier discharge has been designed for sterilization of Saccharomyces Cerevisiae and Candida yeasts. Oxygen has been used as the input working gas. The output gas after discharge operation was a mixture of both ozone and oxygen, with concentration that depends on the applied voltage between the electrodes, gap space and gas flow rate. Sterilization process has been done in two ways, by direct exposure to oxygen plasma inside the discharge cell and by indirect exposure to the plasma. Survivor curves, and scanning and transmission electron microscope were used to study the inactivation kinetics and morphology of the yeast surface before and after sterilization. It has been found that the indirect sterilization causes yeast inactivation in a short time, less than three minutes, while the direct sterilization took place in a longer time, more than ten minutes.Sagradili smo posudu s usporednim pločama i dielektričnom pregradom za postizanje izboja na atmosferskom tlaku, namijenjenu za proučavanje sterilizacije mikroba Saccharomyces Cerevisiae i Candida. Radni plin bio je kisik. Izlazni plin iz posude bio je smjesa ozona i kisika, čija je koncentracija ovisna o vaponu izboja među elektrodama, procijepu i brzini protjecanja plina. Sterilizacija se provodila na dva načina, izravnim izlaganjem u izbojnoj posudi i neizravnim izlaganjem plazmi. Za proučavanje kinetike prekida aktivnosti stanične plazme i oblika mikrobne površine rabili smo krivulje preživjelih stanica prije i poslije sterilizacije. Ustanovili smo da neizravna sterilizacija dovodi do prekida aktivnosti mikroba u kratkom vremenu, manje od tri minute, dok je izravna sterilizacija trajala dulje, više od deset minuta

On Asymptotic Pointwise Contractions in Modular Metric Spaces

In this paper we study and prove some new fixed points theorems for pointwise and asymptotic pointwise contraction mappings in modular metric spaces

Synthesis, spectral characterization, cyclic voltammety, molecular modeling and catalytic activity of sulfa-drug divalent metal complexes

Complexes of cobalt(II), nickel(II), copper(II), zinc(II) and Hafnium(II) of general composition [M(L)2(Cl)2] have been synthesized [L = 4-(phenylphosphinylideneamino-N-thiazolylbenzenesulfonamide]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR, SEM, EDX, thermal and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The molar conductance of the complexes in fresh solution of DMSO lies in the range of 7.46–9.13 Ω-1 cm2mol‒1 indicating their non-electrolytic behavior. On the basis of analytical and spectroscopic techniques, octahedral geometry of the complexes was proposed. The ligand acts as bidentate ligand, coordinated through sulfonamide oxygen and thiazole nitrogen atoms. The ligand field parameters were calculated for Co(II), Ni(II) and Cu(II) complexes and their values were found in the range reported for a octahedral structure. The catalytic activities of the divalent metal complexes have been studied in the oxidation of cyclohexane, using environmental friendly oxidant, hydrogen peroxide. Complex with rough surface has shown higher catalytic activity compared to the other complexes. The molecular parameters of the ligand and its Co(II) and Hf(II) complexes have been calculated.Â

Effet de l’arbre Acacia senegal sur la fertilité des sols de gommeraies au Niger

Six gommeraies des trois bassins gommiers du Niger ont été étudiées : Kiki et Kokoiyé dans le bassin gommier occidental, Bader Goula et Azzaî dans le bassin gommier central et Malam Mainari et N’Guel Kolo dans le bassin gommier oriental. L’objectif de l’étude est d’évaluer l’effet d’Acacia senegal sur la fertilité des sols sous et hors houppiers dans ces gommeraies. Les résultats obtenus à travers les paramètres retenus (le pH, le carbone organique (C), l’azote (N), la capacité d’échange cationique (CEC), le phosphore assimilable (P) et la somme des bases échangeables (S) pour appréhender cet effet d’A. senegal sur le sol montrent une amélioration de la teneur en ces éléments dans le sol sous houppier comparativement aux témoins dans la plupart des cas.Mots clés : Acacia senegal, fertilité, sol, gommeraie, Nige

Hybrid and Relaxed Mann Iterations for General Systems of Variational Inequalities and Nonexpansive Mappings

We introduce hybrid and relaxed Mann iteration methods for a general system of variational inequalities with solutions being also common solutions of a countable family of variational inequalities and common fixed points of a countable family of nonexpansive mappings in real smooth and uniformly convex Banach spaces. Here, the hybrid and relaxed Mann iteration methods are based on Korpelevich’s extragradient method, viscosity approximation method, and Mann iteration method. Under suitable assumptions, we derive some strong convergence theorems for hybrid and relaxed Mann iteration algorithms not only in the setting of uniformly convex and 2-uniformly smooth Banach space but also in a uniformly convex Banach space having a uniformly Gateaux differentiable norm. The results presented in this paper improve, extend, supplement, and develop the corresponding results announced in the earlier and very recent literature

Mejora de la producción de lípidos de un prometedor hongo oleaginoso Aspergillus sp. cepa EM2018 para la formación de biodiesel: optimización de las condiciones de cultivo e identificación

Oleaginous fungi have recently gained increasing attention among different microorganisms due to their ability for lipid production for the preparation of biofuel. In the present study, a locally isolated fungus E45, identified genetically as Aspergillus sp. strain EM2018, was found to produce 25.2% of the total lipids content of its dry cell weight (DCW). Optimization of culture conditions was performed and lipid accumula­tion increased by about 2.4 fold (from 25.2% to 60.1% of DCW) when the fungus was grown for seven days in the potato dextrose (50 g/L) liquid medium at pH 5.0, incubation temperature at 30 ºC and inoculum size of 2 × 106 spore/mL. Supplementation of the medium with yeast extract and NaNO3 at a concentration of 0.05% as organic and inorganic nitrogen sources, respectively, increased lipid production (53.3% lipid/dry biomass). Gas chromatography analysis of fungal lipids revealed the presence of saturated (mainly palmitic acid C16:0 (33%) and lignoceric acid C24:0 (15%)) and unsaturated fatty acids in different proportions (mainly linoleic acid C18:2 (24.4%), oleica cid C18:1 (14%) and arachidonic C20:4 (7.4%). These findings suggest this new oleaginous fungus as a promising feedstock for various industrial applications and for the preparation of biodiesel.Los hongos oleagino­sos recientemente están ganando una creciente atención entre diferentes microorganismos debido a sus capaci­dades de producción de lípidos para la preparación de biocombustibles. En el presente estudio, se descubrió que un hongo E45 aislado localmente, identificado genéticamente como la cepa Aspergillus sp. EM2018, produce un 25,2% de lípidos totales de su peso de células secas (DCW). Se realizó la optimización de las condiciones de cultivo y la acumulación de lípidos se incrementó aproximadamente 2,4 veces (del 25,2% al 60,1% de DCW) cuando el hongo creció durante siete días en un medio líquido de dextrosa de papa (50 g/L) a pH 5.0, 30 °C de temperatura de incubación y 2 × 106 esporas/ml de tamaño de inóculo. La suplementación del medio con extracto de leva­dura y NaNO3 a una concentración de 0,05% como fuentes de nitrógeno orgánico e inorgánico, respectivamente, aumentó aún más la producción de lípidos (53,3% de lípidos/biomasa seca). El análisis mediante cromatografía de gases de los lípidos fúngicos reveló la presencia de ácidos grasos saturados (principalmente palmítico C16:0 (33%) y lignocérico C24:0 (15%)) y ácidos grasos insaturados en diferentes proporciones (principalmente linoleico C18:2 (24.4%), oleico C18:1 (14%) y araquidónico C20:4 (7,4%). Estos hallazgos sugieren que este nuevo hongo oleaginoso es una materia prima prometedora para diversas aplicaciones industriales y preparación de biodiésel

Exogenously applied proline enhances Morph-Physiological responses and yield of Drought-Stressed maize plants grown under different irrigation systems

The exogenous application of osmoprotectants [e.g., proline (Pro)] is an important approach for alleviating the adverse effects of abiotic stresses on plants. Field trials were conducted during the summers of 2017 and 2018 to determine the effects of deficit irrigation and exogenous application of Pro on the productivity, morph-physiological responses, and yield of maize grown under two irrigation systems [surface irrigation (SI) and drip irrigation (DI)]. Three deficit irrigation levels (I100, I85, and I70, representing 100, 85, and 70% of crop evapotranspiration, respectively) and two concentrations of Pro (Pro1 = 2 mM and Pro2 = 4 mM) were used in this study. The plants exposed to drought stress showed a significant reduction in plant height, dry matter, leaf area, chlorophyll content [soil plant analysis development (SPAD)], quantum efficiency of photosystem II [Fv/Fm, Fv/F0, and performance index (PI)], water status [membrane stability index (MSI) and relative water content (RWC)], and grain yield. The DI system increased crop growth and yield and reduced the irrigation water input by 30% compared with the SI system. The growth, water status, and yield of plants significantly decreased with an increase in the water stress levels under the SI system. Under the irrigation systems tested in this study, Pro1 and Pro2 increased plant height by 16 and 18%, RWC by 7 and 10%, MSI by 6 and 12%, PI by 6 and 19%, chlorophyll fluorescence by 7 and 11%, relative chlorophyll content by 9 and 14%, and grain yield by 10 and 14%, respectively, compared with Pro0 control treatment (no Pro). The interaction of Pro2 at I100 irrigation level in DI resulted in the highest grain yield (8.42 t ha–1). However, under the DI or SI system, exogenously applied Pro2 at I85 irrigation level may be effective in achieving higher water productivity and yield without exerting any harmful effects on the growth or yield of maize under limited water conditions. Our results demonstrated the importance of the application of Pro as a tolerance inducer of drought stress in maize

Prediction of financial strength ratings using machine learning and conventional techniques

Financial strength ratings (FSRs) have become more significant particularly since the recent financial crisis of 2007–2009 where rating agencies failed to forecast defaults and the downgrade of some banks. The aim of this paper is to predict Capital Intelligence banks’ financial strength ratings (FSRs) group membership using machine learning and conventional techniques. Here the authors use five different statistical techniques, namely CHAID, CART, multilayer-perceptron neural networks, discriminant analysis and logistic regression. They also use three different evaluation criteria namely average correct classification rate, misclassification cost and gains charts. The data are collected from Bankscope database for the Middle Eastern commercial banks by reference to the first decade of the 21st century. The findings show that when predicting bank FSRs during the period 2007–2009, discriminant analysis is surprisingly superior to all other techniques used in this paper. When only machine learning techniques are used, CHAID outperform other techniques. In addition, the findings highlight that when a random sample is used to predict bank FSRs, CART outperform all other techniques. The evaluation criteria have confirmed the findings and both CART and discriminant analysis are superior to other techniques in predicting bank FSRs. This has implications for Middle Eastern banks, as the authors would suggest that improving their bank FSR can improve their presence in the market