Tan spot, caused by Pyrenophora tritici-repentis (Ptr), is a worrisome destructive foliar disease of wheat-growing areas around the world. Streptomyces spp. have been investigated as biocontrol agents because they beneficially interact with host plants and produce important bioactive substances that can act in the suppression of diseases in plants. In the present study, antifungal activity and plant growth-promoting of Streptomyces spp. strains 6(4), R18(6), and their consortium, were evaluated through in vitro and greenhouse assays. The Ultra High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-QTOF MS) technique was used to analyze the crude extract of each strain. The results of the in vitro tests showed that the 6(4) metabolites caused several abnormalities in the conidial germination of Ptr. This strain also produced indole acetic acid (IAA) and siderophores. Strain R18(6) did not alter conidial germination of Ptr, and produced IAA and phosphate solubilizers. In the greenhouse, the treatment ‘seed inoculation plus foliar spray’ with streptomycetes propagules and metabolites contributed to biomass gain, with no statistical difference between the strains ( p < 0.05). Treatments with 6(4) ‘seed inoculation’, ‘seed inoculation plus foliar spray’, and consortium ‘seed inoculation’ showed the lowest percentage of injured area compared to other treatments ( p < 0.05). UHPLC-QTOF MS data showed that erucamide is present in the culture of 6(4), but not in the culture of R18(6). Therefore, this substance is one of those involved in Ptr hyphal abnormalities, and R18(6) use indirect mechanisms of action to control Ptr. We concluded that these Streptomyces spp. and their metabolites have a promising potential for biological control of Ptr to protect wheat plants from tan spot damage.

This study illustrates the antifungal activity of green biosynthesis of a silver nanoparticle solution using one of Sinai’s natural plant extracts, namely Zygophyllum album which was used as a stabilizer and reducing agent to reduce Ag+ to metallic silver. In this study the plant extract was prepared by boiling in water for 10 min., 70% ethanol and wet autoclaving for 5 min. AgNPs were prepared using these three different extract methods. Transmission electron microscope (TEM) and zeta potential techniques were employed to characterize the synthesis of nanoparticles. The size of particles ranged from 6.28 nm to 28.89 nm at x100 and the zeta potential had one peak at –16.6 mean (mV) at area 100% for green synthesized AgNPs from Z. album prepared from boiling in water for 10 min. The size of particles ranged from 6.64 nm to 54.82nm at 100x and the zeta potential had one peak at – 12.9 mean (mV) at 100% area for green synthesized AgNPs from the plant ethanol extract. The size of particles ranged from 9.39 nm to 31.93 nm at 100x and the zeta potential had one peak – 19.8 mean (mV) at 100% area for green synthesized AgNPs from the wet autoclaved plant extract of Z. album for 5 min. All treatments of plant extract and AgNPs solutions, prepared from these plant extracts of Zygophyllum album, were compared with the positive control and Tachigaren – 30% W/P was conducted on the radial growth of F. oxysporium and caused antifungal activity with a high inhibition percent. There was a highly significant difference between the various extraction techniques. Increasing the concentration of treatments was accompanied with a significant effect on Fusarium wilt. Thus, this study may provide a good alternative approach to control Fusarium wilt disease in the field and under storage conditions of vegetables. Our study suggests that silver nanoparticles of plant extracts can be used for controlling Fusarium wilt.

Banana blood disease (BBD), caused by Ralstonia syzygii subsp. celebesensis ( Rsc), is a major threat to banana production in Southeast Asia. This study aimed to assess the resistance of cultivated and wild banana accessions to Rsc and investigate the expression of pathogenesis- related (PR) protein genes, namely PR3 and PR10, in disease-resistant bananas. Bacterial isolates were isolated from infected bananas in Yala Province, Thailand, and their pathogenicity and phylotype were confirmed, along with Rsc-specific PCR. Rsc-resistance banana screening was conducted on 16 banana accessions, including cultivated and wild types, using representative Rsc isolates. ‘Khai Kasetsart 2’ exhibited resistance (R), followed by ‘Raksa’ with moderate resistance (MR). The expression of PR3 and PR10 genes was analyzed in the resistant ‘Khai Kasetsart 2’ and susceptible ‘Hin’ bananas, revealing distinct expression patterns. PR3 showed rapid upregulation on day 1 after inoculation (DAI), while PR10 exhibited sustained upregulation from 1 to 7 DAI in the resistant cultivar. These findings indicate the involvement of PR proteins in the defense response against Rsc and hold promise for future breeding and disease management strategies in bananas.

In this work, the electronic structure and optical behavior and the thermoelectric performance of the known HfNiSn compound have been studied under the substitution of Mn transition metal instead of Ni atoms. Necessary calculations are performed in the framework of DFT first principles studies by applying generalized gradient approximation (PBE-GGA) as well as solving Boltzmann’s semi-classical equations. The entering Mn leads to a change in the electronic structure of HfNiSn and the occurrence of half-metallic ferromagnetic behavior with 100% polarization at the Fermi level. The maximum ZT value obtained for HfMnSn shows that HfNiSn would be suitable for thermoelectric applications at room temperature, both in pure and Mn presence. The examination of optical parameters also indicates good absorption in the visible range for this compound in all cases.

Electrode induction melting gas atomization (EIGA) is a newly developed method for preparing ultra-clean metal powders, and is a completely crucible-free melting and atomization process. Based on conducted several atomization experiments, we found that the fine powder yields obtained during the EIGA process were greatly affected by the status of metal melt flow. While, continuous metal melt flow was beneficial for the yield of fine powders, it was in conflict with the principle described for the vacuum induction melting inert gas atomization (VIGA) process. To understand the critical role of continuous metal melt flow in the EIGA process, a computational fluid dynamics (CFD) approach was developed to simulate the gas atomization process. The D50 particle size of powder prepared by atomization under continuous liquid metal flow was about 70 μm, while that obtained by atomization under non-continuous liquid metal flow was about 100 μm. The diameter distribution results of numerical simulations agreed well with the experimental measurements, which demonstrated the accuracy of our simulation method. This study provides theoretical support for understanding the critical role of continuous metal melt flow and improving fine powder yields in the EIGA process. PACS: 02.60.Cb; 43.28.Py; 41.20.Gz; 81.20.Ev

To investigate the effect of cyclic heat treatment on the microstructure evolution of titanium alloys, TA15 alloys were subjected to different numbers of heat treatment cycles at various temperatures in the (α + β) two-phase region. The resulting microstructure and hardness of the alloy were characterized by using the metallographic microscopy, scanning electron microscopy, and Vickers hardness testing. The morphology of the initial TA15 alloy was nearly equiaxed structure. The α phase content, thickness of the oxygen-rich α layer, and hardness of the TA15 alloy increased with the number of cycles. The morphology of the TA15 alloy changed into the Widmannstatten structure when the alloy underwent six cycles of heat treatment between 970 and 800°C. The thickness of the oxygen-rich α layer and hardness of the alloy increased with the lower limit temperature of the cyclic heat treatment. Compared with the number of cycles, the lower limit temperature of the cyclic heat treatment was a more significant factor on the microstructure evolution of the TA15 titanium alloy.

Multiple response optimization of the machining of 17-4 PH stainless steel material, which is difficult to process with traditional methods, with EDM was made by Taguchi-based grey relational analysis method. Surface roughness (Ra), material removal rate (MRR), and electrode wear rate (EWR) were the responses, while current, pulse-on time, pulse-off time, and voltage were chosen as process parameters. According to the multi-response optimization, the experiment level that gave the best result was A1B2C2D2. Optimum machining outputs were found as A1B3C1D1 using the Taguchi method. As a result of the Taguchi analysis and ANOVA, it was determined that the significant parameters according to multiple performance characteristics were current (56.22%) and voltage (22.40%). The surfaces of the best GRG and optimal sample were examined with XRD, SEM and EDX analysis and the effects on the surfaces were compared.