Critical Evaluation and Optimization of the Thermodynamic Properties and Phase Diagrams of the CaO–FeO, CaO–MgO, CaO–MnO, FeO–MgO, FeO–MnO, and MgO–MnO Systems

All available thermodynamic and phase diagram data at 1 bar pressure have been critically assessed for the liquid and solid (rock salt structure) phases of the six binary systems formed among the components CaO, FeO, MgO, and MnO. In the case of FeO-containing systems, data were evaluated at Fe saturation. All reliable data for each system were optimized simultaneously to give one set of model equations for the liquid and solid solutions. In systems for which the liq-uidus or solidus curves have not been measured, they were calculated. The thermodynamic properties and phase diagrams calculated from these equations are self-consistent and are the most reliable currently available estimates of the true values.     

Effect of styrene–isoprene–styrene,styrene–butadiene–styrene,and styrene–butadiene–rubber on the mechanical,thermal, rheological,and morphological properties of polypropylene/polystyrene blends

The mechanical, thermal, rheological, and morphological properties of polypropylene (PP)/polystyrene (PS) blends compatibilized with styrene–isoprene–styrene (SIS), styrene–butadiene–styrene (SBS), and styrene–butadiene–rubber (SBR) were studied. The incompatible PP and PS phases were effectively dispersed by the addition of SIS, SBS, and SBR as compatibilizers. The PP/PS blends were mechanically evaluated in terms of the impact strength, ductility, and tensile yield stress to determine the influence of the compatibilizers on the performance properties of these materials. SIS‐ and SBS‐compatibilized blends showed significantly improved impact strength and ductility in comparison with SBR‐compatibilized blends over the entire range of compatibilizer concentrations. Differential scanning calorimetry indicated compatibility between the components upon the addition of SIS, SBS, and SBR by the appearance of shifts in the melt peak of PP toward the melting range of PS. The melt viscosity and storage modulus of the blends depended on the composition, type, and amount of compatibilizer. Scanning electron microscopy images confirmed the compatibility between the PP and PS components in the presence of SIS, SBS, and SBR by showing finer phase domains. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 266–277, 2003     

Chemical Signals in the Stingless Bee, <Emphasis Type="Italic">Frieseomelitta varia</Emphasis>, Indicate Caste,Gender, Age,and Reproductive Status

Chemical compounds on the cuticle are a rich source of information used during interactions among social insects. Despite the multitude of studies on these substances and their function in ants, wasps, and honeybees, little is known about this subject in stingless bees (Hymenoptera: Apidae, Meliponini). We studied the chemical composition of the cuticle of the stingless bee, Frieseomelitta varia, by gas chromatography-mass spectrometry (GC-MS), to investigate potential chemical variation among castes, gender, age, and reproductive status. We found differences in the cuticular hydrocarbon composition among workers, males, and queens, recording both qualitative and quantitative differences among individuals of different ages and gender. The cuticle of physogastric queens presented a chemical profile that was distinct from all other groups in the analysis, with high relative abundances of alkenes and alkadienes with 27, 29, and 31 carbon atoms. We discuss the possibility that these compounds signal a queen’s presence to the colony, thereby initiating all vital worker-queen interactions.     

Molecular Biology of the Cell,Sixth Edition; ISBN: 9780815344643; and Molecular Biology of the Cell,Sixth Edition,The Problems Book; ISBN 9780815344537

The latest edition maintains the excellence and appeal of the previous editions. Its clear text and outstanding illustrations, together with the complementary problems book make this an essential companion for students and lecturers alike.     

Formation and Properties of Low-Melting Glasses in the Ternary Systems As—TI—S, As-TI-Se, and As—Se—S

Glass formation has been found to be extensive in the systems As-TI-S, As-Tl-Se, and As-Se-S. Glasses in these systems exhibit unique low-melting properties; some are highly fluid as low as 185OC. The marked effect of thallium in lowering the viscosity of binary As-S melts was found to be unique among all the metallic additives studied. The glasses are stable, covalent, chemically durable, and dielectric. They exhibit good wetting properties with respect to most metals, and the permeability of the seals formed as well as the volume permeability of the glasses themselves appears to be extremely low. Linear thermal expansion coefficients of some compositions are high, but associated thermal cracking problems are minimized to some extent by the low softening temperatures. The glasses can be evaporated and directly condensed (in uacuo) to form continuous, grain-free glassy films. The glasses are of considerable interest in the study of the nature of the vitreous state. In addition, their over-all properties make them potentially useful for hermetic sealing of semiconductor and other moisture-sensitive electronic components which might be damaged by high-temperature sealing processes.     

Synthetic Procedures Yielding Targeted Nitro and Nitroso Derivatives of the Propellant Stabilisers Diphenylamine,N‐Methyl‐4‐nitroaniline,and N,N′‐Diethyl‐N,N′‐diphenylurea

Synthetic methodologies have been developed which yield a variety of diphenylamine (DPA) and 1,3‐diethyl‐l,3‐diphenylurea (ethylcentralite or EC) propellant stabiliser degradation derivatives in high yield. The N‐alkyl nitroanilines (N‐methyl‐2,4,6‐trinitroaniline; N‐methyl‐2,4‐dinitroaniline; N‐ethyl‐2,4,6‐trinitroaniline; N‐ethyl‐2,4‐dinitroaniline; N‐ethyl‐4‐nitroaniline; N‐ethyl‐2‐nitroaniline) have been obtained either by reaction of the parent aniline with the required alkyl halide under mild conditions or via Ullmann type chemistry. A robust and high yielding approach for the synthesis of di, tri and tetranitrodiphenylamines (2,2′,4,4′‐tetranitrodiphenylamine; 2,4,4′‐trinitrodiphenylamine; 2,2′,4‐trinitrodiphenylamine; 2,4,6‐trinitrodiphenyl‐amine; 2,4‐dinitrodiphenylamine) is reported which involves passing the nitroanilines and chloronitrobenzenes down a base activated alumina column. The N‐nitroso‐N‐alkyl compounds (N‐nitroso‐N‐ethyl‐4‐nitroaniline; N‐nitroso‐N‐ethyl‐2‐nitroaniline; N‐nitroso‐N‐Methyl‐4‐nitroaniline; N‐ethyl‐N‐nitrosoaniline; N‐nitroso‐2‐nitrodiphenylamine) have been synthesised using nitrosyl acetate in acetic acid as the N‐nitrosating agent.     

Evaluation of a new instrument offering sodium,potassium, and ionized calcium in combination with haematocrit,pH and blood gas analysis; the performance of the Nova Stat Profile 1

The Nova Stat Profile 1 analyser, a combined sodium, potassium, ionized calcium, haematocrit and conventional blood gas analyser, was evaluated over a four month period. In addition to assessing and demonstrating that the instrument met analytical requirements, an appreciation of the use of ionised calcium (iCa) was made. Prospective costs were characterised and practical problems of iCa measurement addressed.     

Kairomonal Response of the Parasitoid, <Emphasis Type="Italic">Bracon hebetor</Emphasis> Say,to the Male-Produced Sex Pheromone of Its Host,the Greater Waxmoth, <Emphasis Type="Italic">Galleria mellonella</Emphasis> (L.)

Bracon hebetor is a larval ectoparasitoid that utilizes several pests belonging to the family Pyralidae (Lepidoptera) as hosts. In the present study, we analyzed the kairomonal response of this wasp to the male-produced sex pheromone of a host, the greater wax moth Galleria mellonella, an economically important pest of honeybees, Apis mellifera. Coupled gas chromatography-electroantennographic detection (GC-EAD) revealed three compounds in headspace collections from male G. mellonella that elicited responses from B. hebetor antennae: decanal and the previously identified sex pheromone components, nonanal and undecanal. Y-tube olfactometer tests that used naïve, mated wasps showed that females, but not males, were highly attracted to (a) male G. mellonella headspace samples, (b) two synthetic blends of nonanal and undecanal (in ratios matching that found in male moth samples), and (c) the two aldehydes tested individually. Further, female wasps did not discriminate between a blend of aldehydes and male G. mellonella headspace. In dose-response trials that used octanal, nonanal, decanal, and undecanal, no difference in EAG responses of the two sexes was observed, except for undecanal at the second highest dose, for which female antennae showed significantly larger responses than did male antennae. When the two binary blends were tested at different doses, female wasps were significantly attracted to the two highest doses (1 µg and 10 µg), but not to the lowest dose (100 ng). Our results show that females of this economically important parasitoid utilize the male-produced sex pheromone of a host as an indirect cue to guide them to potential oviposition sites.     

戊二酸在冰醋酸和环己酮、环己醇及五种混合溶剂中的溶解度的测定

By using the laser-monitoring technique, solid-liquid equilibrium data of glutaric acid in cyclohexanol, cyclohexanone, their five mixed solvents and acetic acid were measured within the temperature range from 292.15K to 354.60K by dynamic method. Empirical formula and λh equation were used to correlate the solubilities of glutaric acid in eight solvents. The maximal average relative deviations were 1.15% and 2.20% by using the empirical formula and λh equation to correlate the solubility data. The results showed that the empirical formula and λh model could correlate the solubility data of glutaric acid in eight solvents. In addition, the solubility data of glutaric acid in five mixtures （cyclohexanone＋cyclohexanol） could be predicted with the NRTL equation utilizing the parameters of the binary systems. The total average relative deviation was 3.60%. The results indicate that the NRTL equation could well predict the solubilities of glutaric acid in the mixed solvents of cyclohexanone and cyclohexanol.     

Chemical Composition of the Defensive Secretion of the Longhorned Beetle, <Emphasis Type="Italic">Chloridolum loochooanum</Emphasis>

Adults of the longhorned beetle, Chloridolum loochooanum Gressitt (Coleoptera: Cerambycidae) emit a white frothy secretion from their metasternal glands. This defensive substance contains cyclopentanoid monoterpenoids (iridodials), whose structures were elucidated by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses that compared the naturally occurring structures with synthesized versions. Optically active citronellals, [(S)-, (R)-, and (S)/(R)- mixture], were used as starting materials for synthesizing the corresponding iridodials for the determination of the absolute configuration of the natural product. The retention time of (2S)-iridodial, derived from (S)-citronellal, corresponded to that of C. loochooanum iridodial by enantioselective GC analysis. Thus, we suggest that the absolute configuration of C. loochooanum iridodial is (1R,2S,5S)-iridodial.     

Effect of block composition on the morphology,hydration, and transport properties of sulfonated PS‐b‐PEGPEM‐b‐PS

This work discusses the effect of block composition on the properties of proton conducting polymer membranes. A homopolymer and two block copolymers were synthesized using atom transfer radical polymerization. The homopolymer poly(ethylene glycol phenyl ether methacrylate) (PEGPEM) was used as a bifunctional macroinitiator. Polystyrene (PS), was added to both sides of PEGPEM (A) with two different percentages of PS (B) (i.e., 18 and 31%). These copolymers, BAB 18, BAB 31 and the homopolymer A, were completely sulfonated (SA, SBAB 18 and SBAB 31). The resulting polymers produced different water absorption values and transport properties for direct methanol fuel cell (DMFC) applications. The nanostructure and morphology of the casted membranes were studied using small‐angle X‐ray scattering and atomic force microscopy. The results revealed that all six membranes exhibited a disordered phase‐segregated morphology, which changed on sulfonation into small‐interconnected ionic domains. Normalized DMFC selectivities (proton conductivity over methanol permeability divided by the respective values for Nafion^®) were calculated and ranged from 1.16 (SBAB 31) to 15.30 (BAB 18), indicating that the performance of these materials can be comparable or better than Nafion^®. Transport property results also suggest that chemistry (block nature and composition), morphology and water content play a critical role in the transport mechanism of protons and methanol. For example, the percentage of B in BAB 18 provides shorter interstitial ionic distances and sufficient water content to produce high proton conductivity, while maintaining low methanol permeability in a multi‐ionic proton exchange membrane. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44343.     

Investigation of the properties of decaoxyethylene <Emphasis Type="Italic">n</Emphasis>-dodecyl ether,C<Subscript>12</Subscript>E<Subscript>10</Subscript>, in the aqueous sugar-rich region

Interfacial, thermodynamic, and morphological properties of decaoxyethylene n-dodecylether [CH₃ (CH₂)₁₁(OCH₂CH₂)₁₀OH](C₁₂E₁₀) in aqueous solution were analyzed by tensiometric, viscometric, proton nuclear magnetic resonance (NMR), and small-angle neutron scattering (SANS) techniques. Dynamic and structural aspects at different temperatures in the absence and presence of sugars at different concentrations were measured. Critical micelle concentrations (CMC) were determined by surface tension measurements in the presence of ribose, glucose, and sucrose. The heat capacity (ΔC _p.m.), transfer enthalpy (ΔH _m.tr.), transfer heat capacities (ΔC _p.m.tr.), micellization constant (K _m ), Setchenow constant (K _S ^N ), and partition coefficient (q) were determined and discussed as an extension of the usual thermodynamic quantities of micellization and adsorption at the air-water interface. An enthalpy-entropy compensation effect was observed with an isostructural temperature (T _c ) of about 310 K for both micellization and interfacial adsorption. SANS measurements were taken to elucidate structural information, viz., aggregation number (N _agg), shape, size, and number density (N _m ) on C₁₂E₁₀ micelles in D₂O at different concentrations of sugars (0.05, 0.02, 0.3, and 0.5 M) and temperatures (30, 45, and 60°C). Intrinsic viscosity gave the hydrated micellar volume (V _h ), volume of the hydrocarbon core (V _c ), and volume of the palisade layer of the oxyethylene (OE) unit (V _OE). SANS, as well as rheological data, supported the formation of nonspherical micelles with or without sugars. By SANS, we also observed that at the studied temperature intervals, oblate ellipsoid micelles changed into prolate ellipsoids and the number density of micelles decreased with an increase in temperature both in the presence and in the absence of sugars and also on increasing the concentration of sugars. Proton NMR showed a change in chemical shift of the OE group of micelles above the CMC. We also studied the phase separation of C₁₂E₁₀ by sugars in cloud point measurements.     

A lattice‐fluid,group‐contribution treatment of the glass transition of homopolymers,copolymers, and polymer solutions

The glass transition temperature of polymers and polymer solutions was approached through a combination of the group‐contribution, lattice‐fluid equation of state and the Gibbs–DiMarzio criterion. The model assumes zero entropy at the glass transition temperature and treats molecules as semiflexible chains. This stiffness is associated with a flex energy obtained from the glass transition temperature at atmospheric pressure. Whereas the application of the model is straightforward for homopolymers and polymer solutions, a new formalism using the dyad concept was developed for copolymers. It takes into account the copolymer composition as well as the sequencing of the monomers. The results obtained are consistent with experimental data. For polymer solutions, the model predictions are semiquantitative depending on the system. The interaction parameter required for binary systems was found to have little effect on the glass transition temperature predictions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 697–705, 2003     

Thermal behavior,morphology, and the determination of the Flory–Huggins interaction parameter of polycarbonate–polystyrene blends

Blends of bisphenol-A polycarbonate (PC) and polystyrene (PS) prepared by screw extrusion and solution casting have been investigated with weight fractions of PC in the blends varying from 0.95 to 0.05. From the measured glass transition temperatures (T_g) and specific heat increments (ΔC_p) at the T_g, the polystyrene appears to dissolve more in the PC phase than does the PC in the PS phase. The blend appears to be near eqilibrium under extrusion conditions so that the polymer–polymer interaction parameter of PC/PS blends was calculated and found to be 0.038±0.004 for extruded blends at 250°C. Scanning electron microscopy supports the conclusion that the compatibility increases more in the region of PS-rich compositions than in the regions of PC-rich compositions of the PC/PS blends.     

Effect of ambient‐temperature and high‐temperature electron‐beam radiation on the structural,thermal, mechanical,and dynamic mechanical properties of injection‐molded polyamide‐6,6

Electron‐beam irradiation of injection‐molded specimens of polyiminohexamethyleneiminoadipoyl (better known as polyamide‐6,6) was carried out in air at ambient temperature (303 K) and a high temperature (393 K). Most of the irradiated specimens were tensile dumbbells, although a few were cylinders for compressive stress relaxation testing. A few representative samples were dipped in triallyl cyanurate (TAC) solution before ambient‐temperature irradiation. The gel content of the specimens increased with radiation dose and the temperature of irradiation. Moreover, the TAC‐treated specimens showed an increase in gel content over the neat specimens irradiated at the same dose levels. Wide‐angle X‐ray scattering and differential scanning calorimetry studies revealed that the crystallinity decreased with increasing radiation dose. Irradiation at the high temperature and treatment with TAC further decreased the crystallinity compared to irradiation at ambient temperature. As determined from compressive stress relaxation and mechanical and dynamic mechanical properties, the optimized radiation dose for ambient‐temperature radiation was 200 kGy. The gels had a stiffening effect, and the rate of relaxation decreased significantly. The water‐uptake characteristics of the tensile specimens were investigated; this revealed a decrease in the water absorption tendency with increasing gel content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1633–1644, 2006     

Effect of Co,Ga, and Nd Additions on the Photocatalytic Properties of TiO<Subscript>2</Subscript> Nanopowders

In the present study, metal-ion-doped TiO₂ powders were prepared by a sol-gel process using titanium isopropoxide as a Ti precursor and cobalt, gallium, or neodymium as a dopant. For the prepared doped TiO₂ nanopowders, the photocatalytic behaviors in the decomposition of aqueous 1,4-dichlorobenzene (DCB) were investigated as a function of doping level and preparation conditions. We found that all of the metal ion doping improved the photocatalytic activity of TiO₂, though Nd doping was the most effective and Co doping was least effective. XRD analyses showed that doping with Ga and Nd ions suppresses the anatase-to-rutile phase transition for TiO₂, whereas doping with Co did not influence the phase transition. The UV-visible absorption spectra for these metal-ion-doped samples were red-shifted by ∼ 20–40 nm depending upon the doping level.Original English Text Copyright © 2005 by Fizika i Khimiya Stekla, Whang, J. Kim, E. Kim, Y. Kim, Lee.This article was submitted by the authors in English.