Comparative Analysis of Coding and Non-Coding Features within Insect Tolerance Loci in Wheat with Their Homologs in Cereal Genomes

Food insecurity and malnutrition have reached critical levels with increased human population, climate fluctuations, water shortage; therefore, higher-yielding crops are in the spotlight of numerous studies. Abiotic factors affect the yield of staple food crops; among all, wheat stem sawfly (Cephus cinctus Norton) and orange wheat blossom midge (Sitodiplosis mosellana) are two of the most economically and agronomically harmful insect pests which cause yield loss in cereals, especially in wheat in North America. There is no effective strategy for suppressing this pest damage yet, and only the plants with intrinsic tolerance mechanisms such as solid stem phenotypes for WSS and antixenosis and/or antibiosis mechanisms for OWBM can limit damage. A major QTL and a causal gene for WSS resistance were previously identified in wheat, and 3 major QTLs and a causal gene for OWBM resistance. Here, we present a comparative analysis of coding and non-coding features of these loci of wheat across important cereal crops, barley, rye, oat, and rice. This research paves the way for our cloning and editing of additional WSS and OWBM tolerance gene(s), proteins, and metabolites.     

The effect of different cleaning agents and resin cement materials on the bond strength of contaminated zirconia

The purpose of this study was to examine the effect of different cleaning methods and resin cements on the shear bond strength (SBS) of contaminated zirconia. A total of 92 disc-shaped zirconia specimens were contaminated with different procedures. Then, the specimens were grouped according to cleaning methods and resin cements: no cleaning + Variolink Esthetic DC (CN_V), no cleaning + Panavia V5 (CN_P), sandblasted + Variolink Esthetic DC (SB_V), sandblasted + Panavia V5 (SB_P), Ivoclean + Variolink Esthetic DC (IC_V), Ivoclean + Panavia V5 (IC_P), Katana Cleaner + Variolink Esthetic DC (KC_V), and Katana Cleaner + Panavia V5 (KC_P). Following an aging protocol in a 37°C for 1 week, SBS analysis was performed with a universal test machine. For the surface topography and elemental analysis, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS) were used. Significance was evaluated as p < .05 and p < .01. The highest SBS results were found in the SB_P group, showing a statistically significant difference from all other groups (p < .05). For the same cleaning method, Panavia V5 showed statistically significantly higher SBS values than Variolink Esthetic DC (p < .01), except the CN_P–CN_V (p = .880) and KC_P–KC_V (p = .082) groups. The most detected surface elements by EDS were Zr, O, C, and N, respectively. The contaminated zirconia surfaces must be cleaned for successful adhesion. The use of phosphate-containing adhesives in combination with sandblasting will increase the adhesion strength, and universal cleaning agents can be a good alternative to sandblasting.     

SYNTHESIS AND CHARACTERIZATION OF BORON CARBIDE FILMS BY PLASMA-ENHANCED CHEMICAL VAPOR DEPOSITION

The plasma-enhanced chemical vapor deposition of boron carbide was investigated on quartz glass and alumina substrates from a gas mixture of BCl 3 , H 2 , and CH 4 in an inductively coupled plasma (ICP) medium produced by a radio frequency (RF) discharged onto the gases passing through a tubular reactor under atmospheric pressure. A thin solid boron carbide coating with a gray color was deposited on both substrates. The results of XRD revealed that the major solid phase formed in the coating material was β-rhombohedral B 4 C. The SEM analysis showed that the surface homogeneity increased with an increase in the exposure time, and different boron carbide structures were formed at different RF powers and exposure times.     

CVD of boron and dichloroborane formation in a hot-wire fiber growth reactor

Chemical vapor deposition (CVD) of boron by hydrogen reduction of BCl₃ on a hot tungsten substrate was investigated in a parallel flow reactor. Effect of substrate temperature (1100–1250°C) on the relative rates of formation of BHCl₂ and boron was observed by the on-line analysis of the reactor effluent stream composition using an FT-IR spectrophotometer. It was concluded that BHCl₂ was majorly formed in the gas phase within the thermal boundary layer adjacent to the substrate with possible contribution of surface reactions at higher temperatures. Comparison of results obtained in the impinging jet and parallel flow reactors indicated the significance of diffusion resistance in the parallel flow system. Tubular flow reactor experiments indicated that BHCl₂ formation reaction started at temperatures as low as 350°C and reached equilibrium in less than a second at temperatures over 420°C.     

Production of B4C coatings by CVD method in a dual impinging‐jet reactor: Chemical yield,morphology, and hardness analysis

β‐rhombohedral boron carbide (B₄C) was deposited on a tungsten substrate from a BCl₃? H₂? CH₄ gas mixture in a dual impinging‐jet chemical vapor deposition reactor. On‐line FTIR analysis of the product stream proved the formation of BHCl₂ and HCl as by products, in a competing parallel reaction. A maximum of 13% chemical yield of boron carbide was observed, and the yield was found to have increasing trend with an increase in temperature. XRD analysis proved the existence of rhombohedral B₄C phase at 1300°C without any other B₄C phases or impurities. At this temperature, the formation of 5‐fold icosahedral boron carbide crystals up to 30 micron sizes was observed. Such highly symmetric crystalline regions were observed to have a very high hardness value of 4750 kg/mm² as revealed from the microhardness analysis. The change in product morphology at low substrate temperatures resulted in a decrease in the hardness values. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Mechanism studies on CVD of boron carbide from a gas mixture of BCL3, CH4, and H2 in a dual impinging‐jet reactor

Nearly pure boron carbide free from impurities was produced on a tungsten substrate in a dual impinging‐jet chemical vapor deposition reactor from a BCl₃, CH₄, and H₂ mixture. The Fourier Transform Infrared (FTIR) analysis proved the formation of reaction intermediate BHCl₂, which is proposed to occur mainly in the gaseous boundary layer next to the substrate surface. Among a large number of reaction mechanisms proposed only the ones considering the molecular adsorption of boron carbide on the substrate surface gave reasonable fits. In the proposed mechanism dichloroborane is formed in the gas phase only as a by‐product. Boron carbide, on the other hand, is formed through a series of surface reactions involving adsorbed boron trichloride, adsorbed methane and gas phase hydrogen. The simultaneous fit of the experimental rate data to the model expressions gave correlation coefficient values of 0.977 and 0.948, in predicting the B₄C and BHCl₂ formation rates, respectively. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Gas phase reaction kinetics in boron fibre production

In the production of boron fibres using the chemical vapor deposition (CVD) technique, boron deposition and dichloroborane formation reactions occurs simultaneously. Boron deposition reaction occurs at the surface, whereas the formation of dichloroborane is the result of both gas phase and surface reactions. A continuous stirred tank reactor (CSTR) type of reactor was designed to investigate the reaction kinetics and kinetic parameters in the gas phase reactions of boron trichloride and hydrogen. It was concluded that reaction rate of the product increased with an increase in the inlet concentration of both reactants (BCl₃ and H₂) and with an increase in the reactor temperature. While reaction order with respect to BCl₃ was almost constant at about 0.5 at each temperature, reaction order with respect to hydrogen increased significantly at temperatures lower than 350°C. A general rate expression was derived for BHCl₂ formation from BCl₃ and hydrogen. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Synthesis of TPA impregnated SBA‐15 catalysts and their performance in polyethylene degradation reaction

Tungstophosphoric acid (TPA)‐containing mesoporous santa barbara amorphous (SBA)‐15 materials were synthesized by impregnation of TPA into hydrothermally synthesized SBA‐15. TPA was incorporated to the porous framework of silica with different W/Si ratios, using TPA hydrate as the acid source. The synthesized materials had a surface area range of 212–825 m² g^?1, depending on the TPA loading and exhibited Type IV adsorption–desorption isotherms. Energy dispersive spectrometry and X‐ray photoelectron spectroscopy (XPS) analyses showed that TPA was successfully penetrated into mesopores of the SBA‐15 material. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis of the pyridine adsorbed synthesized materials revealed the existence of Lewis and Brønsted acid sites in the synthesized materials. Their performances were tested in the degradation of polyethylene by thermogravimetric analysis. An increase in TPA content significantly lowered the degradation temperature and activation energy of the polyethylene degradation reaction. In the presence of TPA‐incorporated SBA‐15 catalyst, activation energy was reduced to approximately half‐value of the value found in the absence of the catalyst. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2466–2472, 2012     

Synthesis and characterization of boron carbide films by plasma-enhanced chemical vapor deposition

The plasma-enhanced chemical vapor deposition of boron carbide was investigated on quartz glass and alumina substrates from a gas mixture of BCl 3 , H 2 , and CH 4 in an inductively coupled plasma (ICP) medium produced by a radio frequency (RF) discharged onto the gases passing through a tubular reactor under atmospheric pressure. A thin solid boron carbide coating with a gray color was deposited on both substrates. The results of XRD revealed that the major solid phase formed in the coating material was β-rhombohedral B 4 C. The SEM analysis showed that the surface homogeneity increased with an increase in the exposure time, and different boron carbide structures were formed at different RF powers and exposure times.