Static and Fatigue Behavior of Thick Pultruded GFRP Plates with Surface Damage

Glass fiber-reinforced polymer (GFRP) bridge decks suffering frequent cyclic loading of heavy wheels require relatively thick pultruded composites. To examine the behavior of 12 mm thick pultruded GFRP plates containing surface layers and to study the influence of surface damage, which may be present on such decks, static and fatigue tensile tests were carried out. Severe indentation yielded not only visible damage, but also an invisible damage in the unidirectional layer. Loss of cross section area due to both damages affected the static ultimate loads. Fatigue cracks were found around higher stress concentrations on the surface layer as early as approximately 10% of the total fatigue life. These initial cracks, however, barely affected the fatigue life because delamination of the surface layers prevented the cracks from propagating. The invisible shear crack due to indentation barely affected the fatigue life since earlier splitting between initially damaged and undamaged fibers mitigated the crack propagation.     

Psychological effects on surviving family members of seeing the deceased person after forensic autopsy.

In medicolegal autopsy, it is essential to consider the emotions experienced by relatives of the deceased person. This study examined the psychological effects on surviving family members of seeing the deceased person’s body after forensic autopsy. Participants (n = 359) were surveyed by means of a questionnaire designed to measure posttraumatic symptoms; 62 participants had been involved in traumatic events related to the bereavement (trauma-involved group), and 297 participants had not (no-involvement group). Statistical analyses using structural equation modeling (SEM) showed that the model implying a significant difference between these groups was better fitted, than that implying no difference. The trauma-involved group showed a higher score for posttraumatic symptoms than the no-involvement group (Ms = .32 and .00, respectively). However, there was a negative correlation in the trauma-involved group between seeing the deceased person after forensic autopsy and posttraumatic symptoms (r = ?.43), but there was no correlation (r = ?.01) in the no-involvement group. Furthermore, factor structure for posttraumatic symptoms in bereaved people showed that treatment focused on avoidance behavior would be most effective Japan. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The friction behavior of Ni-, SiO2- and mica sodium silicate-based solid lubrication composites

The friction behavior of Ni⁻-, SiO⁻₂- and mica sodium silicate-based lubricant composites, which included BN, WS₂ and graphite as lubricants, were examined. A ring-on-disk apparatus, in which a solid lubricant composite disk was held against a rotating stainless ring, was used as the test configuration. The tests were run with a load from 62 to 250 N in temperatures from 20 to 800°C in the laboratory environment. The wear surface was characterized by scanning electron microscope and X-ray photo spectroscopy. The major findings were that both mica sodium silicate- and SiO⁻₂-based composites failed at above 500°C due to severe wear and surface damage; in contrast, Ni⁻-based composite showed a stable friction coefficient and low wear from 20 to 800°C.     

Liquid rubber as a reactive softener for 1-chlorobutadiene–butadiene rubber

Blending of hydroxyl-terminated liquid butadiene rubber (HT-BR) with 1-chlorobutadiene–butadiene rubber (CB–BR) was carried out in the presence of isopropylidenedicyclohexyl diisocianate (IPCI) or sulfur as a curing agent, It was found that the HT-BR/CB–BR blend displayed a good plasticity, i.e., its Mooney viscosity became lower than that of CB–BR, which brought abcut a good processability. The HT-BR fraction (E_s from the HT-BR/CB–BR blend vulcanizates, which was prepared by the IPCI-cured system, was evaluated to be ca. 20% by the equilibium swelling test in benzene. The E_s of the sulfur-cured blend was ca. 70% This result shows that HT-BR acted as a reactive softener when it was compounded with CB–BR by curing with the diisocyanate. The tensile strength of the IPCI vulcanizate was exceedingly higher than that of sulfur-cured vulcanizate at all blend raios of HT-BR to CB–BR. © 1996 John Wiley & Sons, Inc.     

Characterization of BAMO/NMMO Copolymers

The compositions and microstructures, thermolyses, and sensitivities of 3,3-bis(azidomethyl)oxetane (BAMO) copolymers with 3-nitratomethyl-3-methyloxetane (NMMO) were characterized. The molar ratios of monomers fed in the copolymerizations were: BAMO/NMMO = 8/2, 7/3, and 6/4. The observed compositions were 81/19, 68/32, and 60/40, respectively. The relative compositions of trade microstructures were also exactly the same as theoretical values. The copolymerization of BAMO with NMMO behaved like an ideal system in the sense that the copolymer has approximately the same composition as the monomer fed. The microstructures of copolymers were also randomly arranged. Poly BAMO showed side chain decomposition in the initial stage of the thermolysis, on the other hand, backbone decomposition controlled the thermolysis of poly NMMO. The BAMO units and the NMMO units appeared to decompose more or less independently of one another and retained their individual decomposition characteristics despite being copolymerized. However, the heat generated by the NMMO decomposition, which occurred at 40°C lower than that of BAMO. activated the reaction of BAMO. Poly B/N(7/3) showed very interesting characteristics in sensitivities, mechanical properties, and the heat of decomposition.     

Solid acidity of metal oxide monolayer and its role in catalytic reactions

Such metal oxide as SO₄²⁻, MoO₃, WO₃, and V₂O₅ spread readily on supports like SnO₂, ZrO₂, and TiO₂ due to the different properties between acid and base oxides to generate the acid site on the monolayer. Number, strength, and structure of the acid site were characterized by temperature-programmed desorption (TPD) of ammonia principally, together with various physico-chemical techniques, and its role for catalytic reactions was studied. Approximately, one to two acid sites were stabilized on 1 nm² of the surface, which consisted of four to eight metal atoms. The limit in surface acid site density was estimated on the monolayer based on the concept of solid acidity on zeolites. Sequence of the metal oxide to show the strong acidity was, SO₄²⁻>WO₃>MoO₃>V₂O₅, and for the support oxide to accommodate the monolayer, SnO₂>ZrO₂>TiO₂>Al₂O₃. From these combinations, the metal oxide monolayer to show the adequate strength of acid site could be selected. Brønsted acidity was observed often, however, the Lewis acidity was prevailing on the reduced vanadium oxide. The structure of acid site, Brønsted or Lewis acid site, thus depended on the oxidation state. Relationship of the profile of solid acidity with various catalytic activities was explained. The solid acid site on the monolayer will possibly be applied to environment friendly technologies.     

Use of <Emphasis Type="Italic">Rhizopus delemar</Emphasis> lipase as compared with other lipases for determination of <Emphasis Type="Italic">sn</Emphasis>-2 fatty acids in triacylglycerol

The FA composition in the sn-2 position of TAG is routinely determined after porcine pancreatic lipase hydrolysis. However, the content of saturated FA increased when a pancreatic lipase preparation with higher specific activity was used. Lipase from Rhizopus delemar was selected as a potential replacement lipase for the following reasons: (i) The FA specificity is nearly equivalent in hydrolysis activity toward FA such as lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and α-linolenic acids; and (ii) lipase from R. delemar hydrolyzes fatty acyl residues at the sn-1,3 positions of TAG. Acyl migration products were present at less than 0.8% in lipase hydrolysates containing 6–14% of sn-2 MAG. A reproducibility CV of less than 5% was obtained in a collaborative study in which the compositions of the main FA at the sn-2 position in olive oil were determined using lipase from R. delemar. This article was presented in part at the Biocatalysis Symposium, 94th AOCS Annual Meeting & Expo, Kansas City, Missouri, May 2003.     

Expression in Escherichia coli of a synthetic gene coding for horse heart myoglobin

A gene for expression of horse heart myoglobin in Escherichiacoli has been constructed in one step from long synthetic oligonucleotides.The synthetic gene contains an efficient translation initiationsignal and used codons that are commonly found in E.coli. Uniquerestriction sites are placed throughout the gene. It has beeninserted in a phagemid vector and is expressed from the lacpromoter in E.coli at high efficiency, the soluble heme proteinrepresenting 10% of soluble protein. Two versions of horse heartmyoglobin were produced with aspartic acid or asparagine atresidue 122. Comparison of chromatographic mobilities of thesetwo proteins with authentic horse heart myoglobin identifiedaspartic acid as the correct residue 122. The availability ofthis gene, which is designed to facilitate oligonucleotide mutagenesisor cassette mutagenesis, will allow systematic structure—functionanalysis of horse heart myoglobin.     

Desorption of Cl- from Mg-Al layered double hydroxide intercalated with Cl- using CO2 gas and water

Mg-Al layered double hydroxide intercalated with CO_3~(2-)(CO_3·Mg-Al LDH) is effective for treating HCl exhaust gas.HCl reacts with CO_3~(2-) in CO_3·Mg-Al LDH, resulting in the formation of Cl·Mg-Al LDH.We propose that CO_2 can be used for the desorption of Cl~-from Cl·Mg-Al LDH to regenerate CO_3·Mg-Al LDH.Herein,we studied the desorption of a from CI-Mg-Al LDH by adding water to Cl·Mg-Al LDH and blowing CO_2 into it.We also analyzed the effects of temperature and water addition speed on the desorption of CI~-from Cl·Mg-Al LDH.Our results show that the added water adhered to CI·Mg-Al LDH and that CO_2 in the gaseous phase was dissolved in this adhered water,thus generating CO_3~(2-).Therefore,anion exchange occurred between CO_3~(2-) and Cl~-in the Cl·Mg-Al LDH,thus desorbing Cl~-.