Digestion and protein metabolism of Trogoderma granarium (Coleoptera: Dermestidae) fed on different barley varieties

The Khapra beetle, Trogoderma granarium Everts, is one of the most important pests of grains which rapidly infests durable stored products in hot and dry conditions. In the current study, effects of omit ten varieties of barley (Abidar, Bahman, Line20, Line22, Line30, Lisivi, Lokht11, Makuyi, Sahand and Sahraa) were determined on digestive enzymes and protein metabolsim of T. granarium larvae under laboratory conditions as 33 ± 1 °C, 65 ± 5% RH and photoperiod of 14:10 (L: D) h. The highest and the lowest activities of α-amylase were observed in T. granarium larvae fed on Line30 and Lisivi varieties, respectively but the glucosidases showed the highest activities followed by feeding on Lokht 11. Also, the latter variety caused the highest lipase activity in the larvae while Abidar, Line20, Lisuei and Sahand imposed the lowest lipase activity. The highest activities of serine proteases including trypsin, chymotrypsin and elastase were detected in the larvae fed on Line 30 but the two exopeptidases, amino- and carboxypeptidases, showed the highest activities when the larvae fed on Lisuei. All the three aminotransferses had the highest activities in the larvae fed on Lokht 11 as the related individuals contained the maximum amount of protein compared to other ones. Results of the current study highlighted Line30 as the most suitable variety to be digested by serine proteases and α-amylase but Lokht11 is appropriately digested by glucosidases and lipase which emboss their susceptibilities to T. granarium. Our findings on digestion and protein metabolism imply on susceptibility of varieties Line30 and Lokht11 to T. granarium larvae.     

A Review on Metal-support Interaction in Automotive Catalysts

TWC-equipped exhausts are widely used in gasoline-fueled vehicles to meet stringent emission regulations. The main components in TWCs are precious metals such as palladium (Pd), platinum (Pt), and rhodium (Rh) as the active component, and inorganic oxides such as γ-alumina (Al 2 O 3 ), ceria (CeO 2 ), zirconia (ZrO 2 ) and ceria-zirconia (CeO 2-ZrO 2 ) are used as the support. Interaction of precious metals and support plays an important role in the thermal stability and catalytic performance of TWCs. The support can improve the dispersion of precious metals and suppress the sintering of precious metals at high temperature. In the same, precious metals can also enhance the redox performance and oxygen storage capacity of support. This paper reviews the reaction phenomenon and mechanism of precious metals (Pt, Pd, Rh) and supports such as Al 2 O 3 , CeO 2-based composite oxides.     

Characterization and gamma radiation effects on poly(methyl methacrylate) doped with some benzylidene polymers

Anionic solution polmerization studies of benzylidene malononitrile, benzylidene ethyl cyanoacetate and their para chloro derivtives in dimethyl formamide (DMF) as a reaction medium using pipridene as initiator under nitrogen atmosphere at 100 °C were carried out. Infrared, ¹H NMR and ultraviolet-visible (UV-Vis) spectroscopic studies for the obtained polymers were investigated. The effect of γ-irradiation on PMMA films doped with 1 % of the benzylidene polymers was investigated by uv-vis spectroscopy. A change in the intensity of absorption bands with increasing irradiation dose was recorded. It is suggested that PMMA films doped with this type of benzylidene polymer can be used as dosimeter.     

Role of elicitation on the health-promoting properties of kidney bean sprouts

The influence of germination of kidney beans for 4, 6 and 8 days in different elicitors (ascorbic acid, folic acid, glutamic acid, glutamic acid/chitosan and lactic acid/chitosan) on the production of health-promoting ingredients was studied. Sprouts were characterized according to their protein profile, soluble phenolic compounds (SPC) and γ-aminobutyric acid (GABA) content. Additionally, the antioxidant and angiotensin-converting enzyme (ACE) inhibition activities of aqueous extracts from kidney bean elicited sprouts were determined. Elicitation by glutamic acid for 8 days led to the highest SPC and GABA accumulation in kidney bean sprouts and their extracts were selected based on their highest phytochemical content. These extracts also showed remarkable antioxidant and ACE-inhibitory activities. The IC₅₀ for ACE inhibition of glutamic acid-extracts increases 89-fold after the in-vitro gastrointestinal digestion. These results will contribute not only to improving the health-promoting potential of kidney bean sprouts but also to obtaining ingredients which might reduce oxidative stress and hypertension.     

Adhesion and Scratch Resistance of Polycarbonate Films on Ferroplate Substrates: Effect of γ-APS Primers

The influence of γ-aminopropyltriethoxysilane (γ-APS) primers on the adhesion and scratch resistance of polycarbonate (PC) films on ferroplate substrates was determined from the critical normal loads at which debonding of the films from the substrates occurred during scratch testing. The critical load was a strong function of the concentration of the aqueous solutions from which the γ-APS primers were adsorbed and of the thickness of the primer films. Thus, the critical normal load increased from 0.09 ± 0.02 N to 0.31 ± 0.07 N as the concentration of the γ-APS solutions increased from 0.05% to 0.2%, respectively. However, the critical load increased only slightly as the solution concentration increased beyond 0.2%. The increase in critical load as concentration of γ-APS solutions increased was related to the formation of an interphase involving chemical reaction and physical entanglement of PC and γ-APS molecules. The critical load for debonding of PC films from the substrates also depended strongly on the temperature at which the γ-APS films were dried before application of the PC films. Thus, the critical normal loads for debonding were 0.31 ± 0.07, 0.20 ± 0.02, and 0.05 ± 0.01 N for γ-APS films that were dried for 15 min at room temperature, 60°C, or 110°C, respectively. The decrease in critical load with increasing drying temperature was attributed to the greater cross-link density in γ-APS films that were dried at elevated temperatures, which limited interdiffusion and physical entanglement of PC and γ-APS molecules. High reaction temperature of γ-APS and PC induced a fragmentation of amine. However, it also increased the probability of amines to react with carbonate because of increasing mobility of PC chains. Optimization of these two factors was required to obtain the greatest adhesion and scratch resistance. Chemical reactions occurring between PC films and γ-APS primers were investigated by reflection–absorption infrared spectroscopy (RAIR) and X-ray photoelectron spectroscopy (XPS) using diphenyl carbonate (DPC) as a model compound. The carbonyl absorption band of neat DPC was observed at 1780 cm^?1. However, two carbonyl bands were observed at 1738 and 1652 cm^?1 in RAIR spectra of γ-APS films that were reacted with DPC and were assigned to urethane and urea groups, respectively. XPS results revealed that urethane was the main reaction product between DPC and γ-APS. It was concluded that urethane groups formed by the reaction of PC with γ-APS were responsible for adhesion and scratch resistance of PC to ferroplate substrates that were primed with γ-APS.     

An investigation on the role of ytterbium in ytterbium promoted γ-alumina-supported nickel catalysts for dry reforming of methane

Addition of low quantities of ytterbium to sol–gel prepared Ni/γ-Al₂O₃ catalysts has been shown to lead to significant increases in catalytic activity and long term stability in the catalytic conversion of CO₂ and CH₄ into syngas (H₂ and CO). The role of ytterbium in these catalysts was investigated in this study through detailed investigations on the structure and composition of ytterbium promoted Ni/γ-Al₂O₃ catalysts using the following techniques: synchrotron X-ray diffraction, X-ray Photoemission Spectroscopy, Transmission Electron Microscopy, Scanning Electron Microscopy/Energy Dispersive X-ray analysis, Temperature Programmed Reduction techniques and N₂ adsorption–desorption isotherms. The results obtained indicated that ytterbium, at small quantities (up to 2 wt%), interacted strongly with the support which in turn altered the interaction between nickel and the support (most notably it was found to completely inhibit the formation of NiAl₂O₄). This decreased interaction between Ni and the support also led to a higher quantity of Ni being present in the catalyst in the form of Ni.     

二苯并噻吩在γ-Al_2O_3负载的β-Mo_2N_(0.78)催化剂上加氢脱硫的研究

采用以N2 -H2 混合气为反应气的程序升温还原氮化反应 ,以γ -Al2 O3 为载体 ,钼酸铵为氧化钼前体 ,合成了γ -Al2 O3 负载的 β -Mo2 N0 78催化剂。以二苯并噻吩 (DBT)为模型化合物 ,考察了催化剂的加氢脱硫 (HDS)催化性能。结果表明 ,DBT在催化剂上的HDS反应有直接氢解脱硫和加氢脱硫两种途径 ;DBT的转化率和产物中环己基苯(CHB)选择性在一定范围内随钼负载量的增大而提高 ;提高反应压力可同时提高HDS反应活性和CHB选择性 ;但升高反应温度 ,只提高HDS反应的活性 ,对选择性影响甚小 ;催化剂的氢气预还原处理使催化剂的活性有所下降 ,但联苯的选择性有所提高     

Analysis for surface coke deposition in used Mo-Co/γ-Al2O3 catalyst for diesel hydrodesulfurization

The coked Mo-Co/γ-Al₂O₃ catalysts were Soxhlet extracted with the solvent of tetrahydrofuran. Experimental techniques like FT-IR, GC-MS, XPS, H₂-TPR, BET, etc. were applied for the characterization of coke and catalysts to make a comparison of their physical properties. The results showed that the active components of the catalyst were slightly less after the reaction. The specific surface area and the pore volume had recovered to some degree. These results indicated that the main cause of deactivation of Mo-Co/γ-Al₂O₃ catalysts is carbon deposit. The principal components of the soluble carbon deposit on Mo-Co/γ-Al₂O₃ catalysts were alkyl aromatics with 1–4 rings and C₁₉–C₂₉ long-chain alkane compounds.     

加氢法合成DL-γ-泛内酯工艺及催化剂研究

采用共沉淀法制备纳米铜基催化剂,用于固定床反应器连续加氢制备DL-γ-泛内酯。结果表明,异丁醛和乙醛酸羟醛缩合产物在反应温度120℃,氢气压力7 MPa,液空速0.6~0.8 h-1,n(H2)∶n(醛)=80∶1条件下连续加氢,DL-泛内酯的收率高达98%。催化剂经过700 h稳定性考察,平均收率96%,反应前后催化剂无明显失活现象,表明催化剂活性稳定,预计有较长使用寿命。