Materials Literature
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Abstract Temperature‐programmed surface reaction (TPSR), temperature‐programmed reaction (TPR) and temperature‐programmed desorption (TPD) were used to study the synthesis of C 2 ‐oxygenates from syngas over Rh–Mn‐based catalysts supported on amorphous silica and mesoporous MCM‐41 supports. Both TPD and TPSR reveal th…
Lipase-catalyzed intermolecular transesterification between two different polyesters has been carried out using in toluene. The transesterification of poly(ε-caprolactone) (PCL) and (1,4-butylene adipate) took place via catalysis of lipase from Candida antarctica to give an ester copolymer. 13C NMR analysis showed tha…
Smectogenic organic compounds are made of rod-like molecules, which often have dipolar groups with lateral components. We argue that since the groups are generally off-axis , the electrostatic contribution to the intermolecular interaction between the neighbours in a smectic layer favours a tilting of the molecules. W…
Samples of Li0.5Fe2.5–xRxO4 (R = Al, Gd, Sm and La; x=0 and 0.1) were prepared by the standard ceramic method. The effect of trivalent ion substitution on the structure and on the magnetic properties of Li-ferrite has been studied. It is found that the Gd ion substitution improves the different magnetic properties of…
The effect of the oxidation state of iron on the phase separation of x Na 2 O·(100 – x )SiO 2 glasses, x = 18.56 and 13, containing 0.5 mol% Fe 2 O 3 was studied. The oxidation state of iron in the glasses was varied by changing the melting conditions, such as melting temperature and melting atmosphere. The oxidation…
[reaction: see text]. A novel convergent approach to fully functionalized ring C allocolchicinoids is developed which is based on the benzannulation reaction of Fischer carbene complexes with alkynes. The efficacy of this strategy was established with the conversion of bromide 1a (R1 = Me, R2 = H) to the biaryl phenol…
This study develops mathematical equations for an important quality of blankets, good handle, based on the compression and surface properties, thickness, weight, and thermal parameters. The handle of blankets is subjectively evaluated by thirty-nine judges. Two methods are investigated for evaluating the quality of bl…
Weld cladding of corrosion resistant materials is an attractive alternative to bulk usage. Such processes are generally associated with potential deterioration of mechanical properties at the clad/metal interface, often attributed to the formation of hard and soft zones which is usually minimised by control of dilutio…
Reflections on the design and remarks on the identification of low-molecular weight thermotropic biaxial nematic mesogens demonstrate unsolved problems in this field of work on liquid crystals of current international interest. However, a cautious outlook on possibilities of syntheses of such highly desirable material…
A nickel‐bearing silicate gel was prepared from sodium disilicate and nickel nitrate solutions at room temperature. Then, the gel was heat‐treated in air up to 800°C at intervals of 200°C. The products were completely amorphous after heating at ≤600°C. However, liebenbergite and cristobalite were identified as product…
Abstract The reaction of Ni2+ with a tripodal hexadentate ligand (H3L = 1,1,1-tris(N-salicylideneaminomethyl)ethane) afforded the O–H···O bridged dinuclear [Ni2(HL)2] complex. When Ni2+ was allowed to react with H3L in the presence of triethylamine (3 : 2 : 6), the linear trinuclear [Ni3(L)2] complex formed, where the…
Banana-shaped five-ring mesogens derived from either isophthalic acid or 4-bromoisophthalic acid have been synthesized. It is shown that the melting and clearing points of the bromine-substituted compounds are markedly decreased in comparison with the analogous unsubstituted compounds. On the basis of X-ray diffractio…
A flexible low-density metallic material, which is extremely transparent, was obtained using as active component the highly conducting molecular metal θ-(BET-TTF)2Br·3H2O, BET-TTF = bis(ethylenethio)tetrathiafulvalene. This material is a bilayer (BL) film that was prepared by treating a polycarbonate film containing 2…
Microscopic polarized fourier-transform infrared (FT-IR) measurements were performed in the antiferroelectric B2 phase of a bent-shaped liquid crystal molecule. In homogeneously chiral domains, the absorbance maximum appeared when the transmission axis of a polarizer was parallel to the layer normal for the phenyl rin…
Riboflavin synthase of Escherichia coli is a homotrimer of 23.4 kDa subunits catalyzing the formation of the carbocyclic ring of the vitamin, riboflavin, by dismutation of 6,7-dimethyl-8-ribityllumazine. Intramolecular sequence similarity suggested that each subunit folds into two topologically similar domains. In ord…
Maltose binding protein (MBP) is widely used as a model for protein folding and export studies. We show here that macroscopic aggregates form transiently during the refolding of MBP at micromolar protein concentrations. Disaggregation occurs spontaneously without any aid, and the refolded material has structure and ac…
Optical anisotropy is generated in films of photochromic LCPs upon irradiation with linearly polarized light. Annealing of these films above the glass transition temperature results in a significant amplification of the photo-induced anisotropy. The amplification takes place even in the case of copolymers with only 10…
The results and analysis of surface resistance measurements performed on nonceramic insulators (NCI) are presented in this paper. The goal of this study was to determine if the surface resistance measurement procedure can be formalized to ensure repeatable and reproducible results. The NCIs evaluated had housing mater…
Abstract Linear poly(organophosphazene)s have been widely investigated, mainly to correlate the structure of inorganic –P=N– backbone bearing organic groups with their properties and functionalites. Our interests have been directed to relatively new types of polymers containing a cyclophosphazene unit in the side chai…
We have succeeded in fabricating a novel FLCD, which exhibits symmetric electrooptic (EO) characteristic called V-shape EO performance, by choosing an appropriate photocuring condition such as applied voltage waveforms and the concentration of photocurable mesogenic monomers. Our mesogenic polymer stabilized (MPS)-V-F…