Synergistic effect of compatibilizer in organo‐modified layered silicate reinforced butadiene rubber nanocomposites

We have prepared nanocomposites of intercalated and exfoliated organosilicates in butadiene rubber (BR) by using a two‐stage melt blending process. We used X‐ray diffraction and transmission electron microscopy to examine, respectively, the intergallery spacing of the organosilicates and their dispersion in the BR. Marked enhancements in the mechanical and thermal properties of BR occurred when it incorporated <10 parts of organosilicates and the loading ratio of the organosilicate to dicarboxylic acid‐terminated butadiene oligomer was approximately three. In particular, the addition of 10 parts of organosilicate and 3 parts of compatibilizer in the BR led to a more than four‐fold increase in the tensile strength, a 150% increase in modulus at 100% elongation (M100), and 232 and 410% enhancements in the tear strength and elongation at break, respectively, relative to those of neat BR. The degradation temperature for the BR nanocomposite containing only a 10‐part loading of organosilicate was 51°C higher than that of neat BR; these increases reduced, however, to 9–13°C upon the addition of the CTB compatibilizer. In addition, the relative water vapor permeabilities of the BR nanocomposites containing 10 parts of organosilicate—both in the presence and absence of the compatibilizer—reduced to 20% of that of the neat BR. POLYM. ENG. SCI. 46:80–88, 2006. © 2005 Society of Plastics Engineers     

Effect of reduction parameters on the particle size of tungsten monocarbide obtained from the blue tungsten oxide

Conclusions A study was made, using the methods of particle size analysis and metallographic examination, of the effects of temperature and bed thickness in the reduction of the blue tungsten oxide upon some properties of tungsten and tungsten monocarbide powders and sintered 6 wt.% Co hard alloys produced from the monocarbide powders. Quantitative results were obtained showing the relationship between these reduction parameters on the one hand and the particle size of the resultant powders and the physicomechanical properties of hard alloys on the other. It was established that the particle size grows with rise in reduction temperature and with increase in the thickness of the blue oxide bed.Translated from Poroshkovaya Metallurgiya, No. 11(143), pp. 102–107, November, 1974.     

Integrated instrumental analysis of soft brown coals

A method for the simultaneous determination of calorific value Q^r, ash yieldA^r and total water content W^r_t of soft brown coals is described. The method involves instrumental analysis of brown coal samples using neutron thermalization and gamma back-scattering techniques. Over 80 coal samples (1.1 kg) were analysed, having Q^rvalues up to 15.5 MJ kg^?1,A^r ranging from 3.6 to 76.1 wt% and W^r_t ranging from 11.4 to 61.7 wt%. A comparison of the results from the instrumental method with those of standard laboratory analyses is given, followed by a discussion of the accuracy of the method and of possible ways for improving it.     

Mutation T-->C of nucleotide 2238 in the gene of atrial natriuretic peptide (ANP) precursor and heterogeneity of sodium-sensitive hypertension. Preliminary report

Atrial natriuretic peptide (ANP) is involved in the pathogenesis of sodium-sensitive hypertension. The loss of Sca I restriction site in the ANP precursor gene abolishes the regular stop codon. The aim of our study was the analysis of the Sca I gene polymorphism in 23 patients with sodium-sensitive hypertension, the molecular characteristic of the mutation and the comparison of the blood pressure values, plasma renin activity, plasma ANP and aldosterone concentration between patients with or without mutation. Applying the polymerase chain reaction (PCR), followed by digestion with Sca I, the heterozygous mutation has been found in 9 (39%) patients. The sequencing of PCR products indicated that the loss of Sca I restriction site is caused by T2238-->C transition leading to the translation of ANP with two additional arginines. The higher concentration of ANP in plasma has been found in T2238-->C transition patients on normal and high sodium diet as compared with patients without mutation. These preliminary results suggest that the heterogeneity of sodium-sensitive hypertension is associated with the T2238-->C mutation of the ANP precursor gene.     

Determination of the ash yield and the mineral matter content of brown coals by density measurements

A method of measuring the density of bed-moist brown coals based on their plastic properties is described and the feasibility of using the method for determination of the ash yield of the coal is evaluated.     

A method for solving the n-dimensional convex hull problem

A method is presented for finding all vertices and all hyperplanes containing the faces of a convex polyhedron spanned by a given finite set X in Euclidean space Eⁿ. The present paper indicates how this method can be applied to the investigation of linear separability of two given finite sets X₁ and X₂ in Eⁿ. In the case of linear separability of these sets the proposed method makes it possible to find the separating hyperplane.     

Physico-Chemical Properties of Cobalt–Ruthenium (10% Co–0.5% Ru) Catalysts Supported on Binary Oxides 8.5%ZrO<Subscript>2</Subscript>/Support (SiO<Subscript>2</Subscript>, Al<Subscript>2</Subscript>O<Subscript>3</Subscript>, TiO<Subscript>2</Subscript>) for Fischer-Tropsch Synthesis

The promotion of Fischer-Tropsch catalysts 10%Co/Al₂O₃, 10%Co/SiO₂, 10%Co/TiO₂ by 0.5% Ru and the modification of supports by 8.5 wt% ZrO₂ have been studied. The following properties: catalyst specific surface area as well as reducibility and dispersion of metallic phase were studied by different techniques: BET, TPR, and H₂ chemisorption. The modification of supports by non-reducible ZrO₂, results in a decrease of cobalt oxide reduction on Al₂O₃ and TiO₂ but not on SiO₂ supports. Additionally the enhancement of cobalt dispersion was found for all catalysts with ZrO₂ modified supports. The impact of Ru promotion is likely due to the stabilization of applied supports, prevention or blockage of interaction between surface Co species and support and an increase in cobalt oxide reducibility to the catalytically active metallic cobalt phase.     

Surface states on the <Emphasis Type="Italic">n</Emphasis>-InN-electrolyte interface

Dependences of differential capacitance of the electrolyte-n-InN (0001) contact on the bias voltage are studied. Their analysis of the basis of a model similar to a model of the MIS structure shows that the energy spectrum of surface states of InN above the conduction band bottom can be represented by two, relatively narrow, bands of deep levels described by the Gaussian distribution. Parameters of these bands are as follows: the average energy counted from the conduction band bottom, ΔE ₁ ≈ 0.15 eV and ΔE ₂ ≈ 0.9 eV; and the mean-square deviation, ΔE ₁ ≈ 0.15–0.25 eV and ΔE ₂ ≈ 0.05–0.1 eV. The total density of states in the bands are (1–2.5) × 10¹² and (0.2–4) × 10¹² cm^–2.