Reaction of polycyclic aromatic hydrocarbons adsorbed on silica in aqueous chlorine

The reaction of polycyclic aromatic hydrocarbons (PAHs) previously adsorbed on silica gel or diatomaceous earth with sodium hypochlorite was carried out to elucidate their reactivity to aqueous chlorine. It was demonstrated that the PAHs adsorbed on silica reacted more rapidly than the PAHs themselves in water, leading to the formation of many chlorinated and oxidized derivatives. A similar reaction in the presence of potassium bromide was found to preferentially produce corresponding brominated derivatives. These reactions seem to proceed through PAHs adsorbed on the silica surface and halogenating agents, the electrophilicity of which may be raised by the catalytic effect of the silanol group of the silica surface. These findings from the environmental viewpoint suggest that the reaction of hydrophobic compounds adsorbed on sediment cannot be neglected.     

The effect of dietary n−6 and n−3 polyunsaturated fatty acids on blood pressure and tissue fatty acid composition in spontaneously hypertensive rats

Effects of dietary n−6 and n−3 fatty acids (FAs) on blood pressure (BP) and tissue phospholipid (PL) FA composition in spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats were compared. Male weanling SHR and WKY were fed a fat-free semisynthetic diet supplemented with 10% (w/w) fats containing (a) 78% 18∶2n−6 (LA-rich), (b) 20% LA and 55% 18∶3n−3 (LN-rich), or (c) 11% LA and 3% LN (CON) for seven weeks. Dietary fats did not affect the BP elevation, but significantly altered the FA composition of brain, adrenal gland, renal medulla and cortex PL in SHR. The LA-rich diet increased n−6 FA while it reduced n−3 FA levels. The levels of 20∶4n−6 were not significantly different between animals fed the LA-rich and the CON diets. LN-rich diet increased the levels of n−3 FAs, while it reduced those of n−6 FAs. However, the extent of change was significantly less in SHR than in WKY. In all dietary groups, SHR, as compared to WKY, had a relatively higher level of the 2 series prostaglandin (PG) precursor, 20∶4n−6, and a relatively lower level of the 1 and 3 series PG precursors, 20∶3n−6 and 20∶5n−3. The possibility that the unbalanced eicosanoid FA precursor levels might contribute to the development of hypertension in this animal model is discussed.     

Geographic Variation in Sex Pheromone of Asian Corn Borer, Ostrinia furnacalis, in Japan

Geographic variation in the sex pheromone of the Asian corn borer, Ostrinia furnacalis (Guenée), was surveyed in populations sampled at four locations ranging from 39.7°N to 32.9°N in Japan. The sex pheromone of the three northern populations was composed of (E)- and (Z)-12-tetradecenyl acetates with a mean E proportion of 36–39%. The southernmost population (Nishigoshi) had the same components but with a significantly higher E composition of 44%. The frequency distribution of the E ratio in the Nishigoshi population exhibited a small peak near 38% and a major peak near 46%. A family-wise analysis of the sex pheromone of this population confirmed that there were two distinct phenotypes regarding the E ratio. An 46% E strain inhabits southern parts of Japan, in addition to an 38% E strain, which seems to be predominant in other regions of Japan.     

Improvement in ozone yield using discharge superposition method

The efficiency of ozonizers using silent discharge is very low compared with the theoretical value. Although many studies have attempted to improve the efficiency of ozonizers, we cannot expect to do so without changing the process of ozone generation. In this study, two high voltages are applied to an ozonizer which has three electrodes (central, surface, and outer electrodes) arranged coaxially, and the phase difference between applied voltages can be changed. The silent and surface discharges are superposed in the same space of the ozonizer. This paper considers the optimum experimental conditions leading to improved efficiency of an ozonizer using the discharge superposition method. It is found that when two kinds of discharges are superposed while using the central electrode as a common‐ground electrode, the maximum ozone yield efficiency is obtained, especially at a phase difference of about 180°. However, when using the surface electrode as a common‐ground electrode, the ozone efficiency is higher at phase differences of about 90° or 270° than at other angles. © 1998 Scripta Technica, Electr Eng Jpn, 126(1): 1–6, 1999     

Molecular Hydrogen as a Novel Antitumor Agent: Possible Mechanisms Underlying Gene Expression

While many antitumor drugs have yielded unsatisfactory therapeutic results, drugs are one of the most prevalent therapeutic measures for the treatment of cancer. The development of cancer largely results from mutations in nuclear DNA, as well as from those in mitochondrial DNA (mtDNA). Molecular hydrogen (H₂), an inert molecule, can scavenge hydroxyl radicals (·OH), which are known to be the strongest oxidizing reactive oxygen species (ROS) in the body that causes these DNA mutations. It has been reported that H₂ has no side effects, unlike conventional antitumor drugs, and that it is effective against many diseases caused by oxidative stress and chronic inflammation. Recently, there has been an increasing number of papers on the efficacy of H₂ against cancer and its effects in mitigating the side effects of cancer treatment. In this review, we demonstrate the efficacy and safety of H₂ as a novel antitumor agent and show that its mechanisms may not only involve the direct scavenging of ·OH, but also other indirect biological defense mechanisms via the regulation of gene expression.     

Numerical Study of Temperature Development of Slurry of Al-Si Alloy in Double-Axis-Electromagnetic Stirrer

Flow and temperature fields of slurry of Al-Si alloy in the process of cup-cast method is numerically simulated.The simulation results agree with the experiment by Shimasaki et al.under an estimated value of the overall heat transfer coefficient between the alloy and the cup.     

Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet

A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified SPR for a quasi-isotropic CFRP laminate was investigated by tensile and fatigue tests on the single lap joints. The experimental results showed that the tensile strength of a modified SPR joint was slightly higher than a bolted joint. In tension–tension fatigue tests, a fatigue limit at N_f = 10⁷ cycles was about 50% of the tensile joint strength. Experimental results showed that the modified SPR was one of the promising fasteners for future mass-production CFRP automobiles.     

Hash-based early recognition of gesture patterns

In these days, “early recognition” of gesture patterns has been studied by many researchers. Early recognition is a method to make a decision of gesture recognition at the beginning part of it. In traditional method, the key postures for a gesture are utilized for recognition and early recognition is performed frame-by-frame. However, this method has a problem that computational time in recognition processing increases in proportion to size of posture database. If the processing time becomes longer, some input frames will be ignored from the processing. It results in lower recognition accuracy. In this paper, we introduce a hash-based approach to search the posture database. It realizes real-time processing, and keep high performance of recognition.     

Artificial lightning testing on graphite/epoxy composite laminate

This study examines the evolution of damage in graphite/epoxy composite laminates due to lightning strikes. To clarify the influence of lightning parameters and specimen size, artificial lightning testing was performed on a series of laminated composite specimens. Damage was assessed using visual inspection, ultrasonic testing, micro X-ray inspection, and sectional observation. The results showed that the damage modes can be categorized into fiber damage, resin deterioration, and internal delamination modes. Damage progression is governed by the strong electrical orthotropic properties of the laminates, and the lightning parameters defining impulse waveform show strong relationship with certain damage modes, though specimen size and thickness variation barely affect damage size.