Effect of Talc Size on Surface Roughness and Glossiness of Polypropylene Injection Molding Application to Automotive Plastics

Talc-containing polypropylene (PP) resin is extensively employed in automobiles. Herein, considering the microstructure transfer process in injection molding, the effect of the talc's dispersibility and particle size on this process and its impact on the gloss level of the product were investigated. Results show that a fine unevenness of about several micrometers was self-formed by the shrinkage of PP in nontransferred areas due to the blending of talc. Additionally, the amount of self-formed unevenness tended with an increase in the average particle size of talc. Furthermore, due to PP shrinkage and different densities of talc, it was observed that a fine tiger-stripe pattern was self-formed using special molds with modified microstructure. This self-formed fine unevenness changes the gloss level owing to the diffused light reflection effect. This study proposes controlling this change by controlling the average particle size of talc and structure of the mold. POLYM. ENG. SCI., 60:132–139, 2020. © 2019 Society of Plastics Engineers     

Removal mechanisms for endocrine disrupting compounds (EDCs) in wastewater treatment - physical means, biodegradation, and chemical advanced oxidation: a review

Endocrine disrupting compounds (EDCs) are pollutants with estrogenic or androgenic activity at very low concentrations and are emerging as a major concern for water quality. Within the past few decades, more and more target chemicals were monitored as the source of estrogenic or androgenic activity in wastewater, and great endeavors have been done on the removal of EDCs in wastewater. This article reviewed removal of EDCs from three aspects, that is, physical means, biodegradation, and chemical advanced oxidation (CAO).     

Effects of isocyanuric acid on the monochlorodimedone chlorinating rates with free chlorine and ammonia chloramine in water

Changes in monochlorodimedone (MCD) chlorinating rates with free chlorine (mixture of HOCl and OCl-) and ammonia monochloramine (NH2Cl) in water at pH 7 by the addition of isocyanuric acid (H3Cy) were determined at room temperature. Decreases in MCD absorbance at 290nm in equimolar (0.04mM) reactions of MCD and free available chlorine solutions containing H3Cy (0.01-1.60 mM) were recorded in a stopped-flow spectrophotometer. The rates indicate second-order reactions. Since the rate with free chlorine was high (> 7.6 x 10(6) M(-1) s(-1)), the amounts of free chlorine in the solutions could be distinguished from that of chlorinated cyanurates. The chlorinating rates with chlorinated cyanurates decreased with an increase in H3Cy concentrations. Plotting the rates against the molar ratio of chlorine to H3Cy showed a linear correlation and the rates with chlorinated cyanurates (H2ClCy) was estimated at 0.5 x 10(5) M(-1) s(-1). In contrast, the rates with the NH2Cl solution containing H3Cy increased with an increase in H3Cy concentrations, increasing from 1.2 x 10 to 2.7 x 10 M(-1) s(-1) by the addition of 1.55 mM H3Cy. The DPD color development rates (OD512/t1/2/M) with free available chlorine (0.015mM) declined from 1.3 x 10(5) to 0.9 x 10(5)M(-1) by the addition of 0.61 mM H3Cy.     

Morphology of CuO through precipitation process under 2.45 GHz microwave irradiation

The morphology of CuO powders formed by a homogeneous precipitation process from aqueous copper precursor complex was investigated. The effect of 2.45 GHz microwave irradiation appeared in the characteristic morphology of the CuO microcrystal with comparison of an ordinal synthesis process. The crystallographic orientation of CuO microcrystals in the particle was examined by HRTEM. Using microwave irradiation, it was demonstrated that the morphology of the particles was kept through the decomposition of the precursor. Also the rapid transformation of a precursor to CuO in aqueous solution under microwave irradiation condition was discussed.     

Electron microscopic observation on the parathyroid gland of the cardiomyopathic hamster (UM-X7.1 Syrian hamster).

The ultrastructure of the parathyroid gland (PTG) of the UM-X7.1 cardiomyopathic hamster (the UM-X7.1) was qualitatively and quantitatively compared with that of the normal hamster. In the UM-X7.1, the Golgi apparatus and rER were well developed compared with those of the control hamster. Morphometric analysis revealed that the mean values of the Golgi apparatus, rER and large vacuolar bodies were significantly greater in the UM-X7.1 than in the normal hamster and the mean value of lipid droplets was significantly less in the UM-X7.1 than in the normal hamster. Ultrastructurally, we consider that in the UM-X7.1, the synthesis and release of the parathyroid hormone may be activated by an excessive amount of circulating catecholamine, and the functional activity of the PTG may be higher than that in the normal hamster.     

Inter-vehicle spread spectrum communication and ranging system withconcatenated EOE sequence

Proposes a method for designing spread sequences for a spread spectrum (SS) communication and ranging system. The proposed sequence is composed by concatenated equivalently odd and even (EOE) inner-sequences and an M outer sequence. We have previously proposed EOE sequences that have equivalently good properties of both even and odd correlation, what are important features for acquisition and demodulation in SS communications. Usually, simple concatenation of pseudonoise-sequences results in sequences with bad autocorrelation properties. Unlike the latter, concatenation of EOE inner sequences result in sequences with good correlation properties, exhibiting low sidelobe peaks, what is useful for achieving stable acquisition. The proposed sequences have long period. Therefore, the single concatenated EOE sequence is suitable for a spread spectrum system with both communication and ranging functions     

Field evaluation of UHF radio propagation for an ITS safety system in an urban environment

Roadside-to-vehicle and vehicle-to-vehicle communication systems have been proposed as part of ITS development to help achieve vehicle safety and realize more secure road traffic environments. In this article we first introduce several typical applications and their radio range requirements for vehicle safety communication systems to clarify the technical point of view. Then we show some field experiment results in an urban area in Tokyo to investigate and verify the radio propagation characteristics and the quality of communications by using a wireless radio prototype system. Finally, we conclude that the current prototype system has potential to fulfill the radio range requirements of vehicle safety communications, but there are still lots of issues that need to be addressed.     

The Effect of Air Foam Inclusion on the Permeability and Absorption Properties of Light Weight Soil

Cement-treated clay with air foam, which is called Super Geo-Material (SGM), was developed to utilize dredged clay in an effective way. As SGM is mainly used at levels below the ground water table, water permeability and absorption properties of SGM will affect the durability of the material. In this research, the changes in SGM permeability and absorption as functions of the air foam fraction were investigated. First, permeability tests with triaxial apparatus and constant rate of consolidation tests were conducted on samples containing less than 10% of air foam by volume. From the results, air foam was found to be an impermeable medium in SGM. Secondly, a series of permeability tests and absorption tests were conducted for the SGM with different fractions of air foam while observing the specimen with a micro focus X-ray Computed Tomography (CT) scanner. The results showed that the permeability of SGM increased dramatically due to the appearance of interior water channels when the air foam fraction exceeded 30% by volume. The density distribution change and water absorbed zones of the specimens during absorption tests were estimated using the X-ray CT data. From these results, the air in the SGM was found to be progressively substituted with water from the surface to the inside of the specimen and the substituted zone expanded as it made its way to the specimen interior. The expansion velocity of the substituted zone was not affected by the coefficient of permeability but by the fraction of the air in the specimen.     

Isolation of Solid Solution Phases in Size‐Controlled LixFePO4 at Room Temperature

State‐of‐the‐art LiFePO₄ technology has now opened the door for lithium ion batteries to take their place in large‐scale applications such as plug‐in hybrid vehicles. A high level of safety, significant cost reduction, and huge power generation are on the verge of being guaranteed for the most advanced energy storage system. The room‐temperature phase diagram is essential to understand the facile electrode reaction of Li_xFePO₄ (0 < x < 1), but it has not been fully understood. Here, intermediate solid solution phases close to x = 0 and x = 1 have been isolated at room temperature. Size‐dependent modification of the phase diagram, as well as the systematic variation of lattice parameters inside the solid‐solution compositional domain closely related to the electrochemical redox potential, are demonstrated. These experimental results reveal that the excess capacity that has been observed above and below the two‐phase equilibrium potential is largely due to the bulk solid solution, and thus support the size‐dependent miscibility gap model.