The aim of the present paper is to investigate the mechanical properties and precipitation behavior of the Al– 4.4Cu–1.5Mg-0.6Mn-0.25Si (wt%) alloy as a function of heat treatment. The X-Ray diffraction analysis (XRD), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Microhardness Vickers test (HV) have been used to examine the effects of microalloying and the origins of hardening precipitates during heat treatment. The combined application of these techniques is particularly important in the study of nanoscale precipitation processes. The solute clusters precede the formation of GP zones or precipitation and have a defining role on the nature and kinetics of the subsequent precipitation processes. The lower values of the activation energy of the precipitate particles indicate that, the driving force of the clustering process is low and the Cu addition to this kind of alloys enhances the clustering process.

In this study, we have demonstrated the fine structure effect of PdCo electrocatalyst on oxygen reduction reaction activity with different alloy composition and heat-treatment time. In order to identify the intrinsic factors for the electrocatalytic activity, various X-ray analyses were used, including inductively coupled plasma-atomic emission spectrometer, transmission electron microscopy, X-ray diffractometer, and X-ray Absorption Spectroscopy technique. In particular, extended X-ray absorption fine structure was employed to extract the structural parameters required for understanding the atomic distribution and alloying extent, and to identify the corresponding simulated structures by using FEFF8 code and IFEFFIT software. The electrocatalytic activity of PdCo alloy nanoparticles for the oxygen reduction reaction was evaluated by using rotating disk electrode technique and correlated to the change in structural parameters. We have found that Pd-rich surface was formed on the Co core with increasing heating time over 5 hours. Such core shell structure of PdCo/C showed that a superior oxygen reduction reaction activity than pure Pd/C or alloy phase of PdCo/C electrocatalysts, because the adsorption energy of adsorbates was apparently reduced by lowering the dband center of the Pd skin due to a combination of the compressive strain effect and ligand effect.

In this study, we investigated the additive treatment effect of TiO2 as alternative support materials to common carbon black for Pt-based electrocatalysts on electrocatalytic activity for oxygen reduction reaction (ORR). The shape of TiO2 was varied by hydrothermal treatment with various additives, such as urea, thiourea, and hydrofluoric acid. From the results of transmission electron microscopy (TEM) images and ultraviolet–visible spectroscopy (UV–vis) spectra, it was identified that the morphology of hydrofluoric acid (HF)-treated TiO2 was changed into a round shape having lower aspect ratio than other samples, and its band gap was decreased. Notably, the electronic state of HF-treated TiO2 support was changed into highly reduced (electron rich) state which led to the increase of ORR activity, compared to other samples treated with different additives or before treatment. The electrocatalytic characteristics changes after treatment with various additives were investigated by using X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), cyclic voltammograms (CV), and rotating disk electrode (RDE) techniques.

In this study, we investigated the heat treatment temperature effect on the morphology and oxygen reduction reaction activity of carbon-supported Pd–Co alloy electrocatalysts. As prepared Pd–Co bimetallic nanoparticles showed a single-phase face-centered cubic disordered structure, and the mean particle size decreased with a Co content. In order to improve activity and stability, the catalysts were heat-treated in a temperature range of 300 to 700 C. From the results of oxygen reduction reaction activity tests, the optimal heat treatment temperature was found to be 700 C for the low Co content samples, while 300 C was the best condition for the high Co content samples.

Abstract: The ability of thiamine (vitamin B1) and ascorbic acid to induce resistance against root rot and wilt disease in safflower cultivar infected with Fusarium verticillioides was studied under laboratory and greenhouse conditions. Infection with Fusarium sp. caused clear reduction in growth parameters (fresh and dry weight of plants, total photosynthetic pigments), soluble sugars and free amino acids comparing with healthy plants (absolute control). In addition it induced the highest accumulation of proline. On the other side, soaking with two levels of thiamine and ascorbic acid lowered the numbers of infected safflower plants, increased dry and fresh weight contents specially in shoots than roots comparing with the infected plants with Fusarium verticillioides. Thiamine concentrations (1,&3mM) induced the highest stimulating effect on total pigments. The induction of resistance by ascorbic acid and thiamine was associated with some biochemical changes in safflower cultivar by reduction of proline content, enhancement of soluble sugars and free amino acids to decrease the disease and increase plant growth.

Abstract: The ability of thiamine (vitamin B1) and ascorbic acid to induce resistance against root rot and wilt disease in safflower cultivar infected with Fusarium verticillioides was studied under laboratory and greenhouse conditions. Infection with Fusarium sp. caused clear reduction in growth parameters (fresh and dry weight of plants, total photosynthetic pigments), soluble sugars and free amino acids comparing with healthy plants (absolute control). In addition it induced the highest accumulation of proline. On the other side, soaking with two levels of thiamine and ascorbic acid lowered the numbers of infected safflower plants, increased dry and fresh weight contents specially in shoots than roots comparing with the infected plants with Fusarium verticillioides. Thiamine concentrations (1,&3mM) induced the highest stimulating effect on total pigments. The induction of resistance by ascorbic acid and thiamine was associated with some biochemical changes in safflower cultivar by reduction of proline content, enhancement of soluble sugars and free amino acids to decrease the disease and increase plant growth.

Abstract: The ability of thiamine (vitamin B1) and ascorbic acid to induce resistance against root rot and wilt disease in safflower cultivar infected with Fusarium verticillioides was studied under laboratory and greenhouse conditions. Infection with Fusarium sp. caused clear reduction in growth parameters (fresh and dry weight of plants, total photosynthetic pigments), soluble sugars and free amino acids comparing with healthy plants (absolute control). In addition it induced the highest accumulation of proline. On the other side, soaking with two levels of thiamine and ascorbic acid lowered the numbers of infected safflower plants, increased dry and fresh weight contents specially in shoots than roots comparing with the infected plants with Fusarium verticillioides. Thiamine concentrations (1,&3mM) induced the highest stimulating effect on total pigments. The induction of resistance by ascorbic acid and thiamine was associated with some biochemical changes in safflower cultivar by reduction of proline content, enhancement of soluble sugars and free amino acids to decrease the disease and increase plant growth.

With steadily growing of the microbial resistance against the classical antibiotics, searching new and effective natural antimicrobial agents become crucial. The study introduces new herbal extracts as antibacterial agents against both Gram-positive and Gram-negative bacteria. In vitro antibacterial activity of 15 weed plant species, collected from Aseer region, Saudi Arabia and their effective minimum inhibitory concentrations (MIC) were determined. The possible mode of action of the most effective plant extracts was investigated. Crude extracts of the investigated species were prepared using three organic solvents. Bacillus subtilis and Proteus vulgaris were used as test organisms to evaluate the antibacterial effect of the crude extracts and their (MIC). Examination with scanning electron microscopy of the treated bacteria as well as analysis of the plant extract using GC-MS were performed to explore the possible mode of action. Foeniculum vulgare, Xanthium spinosum, Abutilon pannosum, Solanum incanum, Forsskaolea tenacissima and Brassica deflexa were the most effective plants among the fifteenth tested species. Scan electron micrographs (SEM) revealed a clear morphological malformation in the bacterial shapes. This supports our hypothesis that extracts could alter the bacterial cell membrane permeability causing plasmolysis. GC-MS analysis of plant extracts proved the presence of aliphatic and aromatic compounds, whereas, the number and types of these compounds depended on the type of the organic solvent. The chloroform extracts of Xanthium spinosum, Abutilon pannosum are very promising antibacterial agents against both Gram-positive and Gram-negative bacteria. Further investigation is recommended to scale up and validate the application of the test plant extracts

This study aimed to enhance the bio-ethanol production from date molasses as a cheap and renewable resource by local species of non-Saccharomyces yeasts by optimization the production’s conditions. Hanseniaspora guilliermondii KKUY-0036 and H. uvarum KKUY-0078 were used based on their ability to ferment the date molasses efficiently. They were identified by the sequencing of D1/D2 domain of the 26S rRNA gene. Their identity was confirmed by comparing the obtained sequence with similar sequences allocated in the GenBank. To enhance the ethanol productivity, temperature, pH, fermentation period, molasses concentration and addition of some elements were optimized. Results revealed that the two yeast species exhibited their maximum productivity of ethanol at 30°C when they were grown on 20-25% of the date molasses after 96-120 h of incubation. The highest ethanol concentration was achieved in weak acidic medium (pH 4-6). Addition of zinc, magnesium and manganese induced the production of ethanol by the two yeasts and the optimum concentrations were 0.6, 0.2-0.3 and 0.03 g LG1, respectively. The study introduces both H. guilliermondii KKUY-0036 and H. uvarum KKUY-0078 as new ethanol-producers that ferment date molasses efficiently and will greatly reduce the biofuel production cost.

The study aimed to assess the effect-combined use different of date palm composts amended with ligno-cellulolytic fungi and mineral-N on growth and N, P and K-uptake of maize plants in sandy calcareous soil. Each type of compost was applied either in organic form in dose equivalent to 100% of N fertilization (285 kg ha-1) or in organic form in combination with mineral-N (50% for each). The experiment was constructed in a complete randomized block design (CRBD). Results showed that plant height and dry weight of shoot and root of maize significantly increased as a result of the combined use of compost with mineral-N (1:1, w:w). All types of composts combined with half-dose of mineral-N was effective, however, compost that contained with Aspergillus niger + A. subsessilis + Trichoderma lanuginosus + Bacillus sp. was the best. This type of fertilization increased N-uptake shoot and root of maize more than mineral N-fertilizer by 39.73%-49%. Inaddition, the P-uptake by shoot and root of maize increased by 58.82%-156%. The addition of compost treatments to the soil increased the total N, P and K after harvesting. Regression analysis showed positive and significant linear correlation between the application rate of compost and the availability of P and K in soil.