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Regular safety inspections in a timely manner are required for safety management and maintenance of structures in order to avoid accidents of the structure. As a way to inspect whether a structure is safe, non-destructive testing method has been widely used for the internal inspection of concrete structure. In spite of several previous studies on non-destructive testing techniques for concrete structures, there is still lack of scientific approaches and experimental validation of non-destructive testing for recycled coarse aggregate concrete hollow columns that are currently widely used in concrete structures, but need for accurate and efficient inspection methods. To address this issue, this study attempts to estimate and verify the thickness of concrete hollow columns using the impact-echo method. To achieve this goal, 40 MPa of mixed design strength according to four replacement ratios of recycled coarse aggregate was used to build an experimental specimen that has a rectangular hollow. The mai...

This research focuses on the non-destructive test method, which is helpful in renovating old buildings without destructing concrete structure, thus estimating compressive strength of the concrete structure is of increasing importance. This paper utilises the ultrasonic pulse velocity method and the spectral analysis of surface wave method to estimate the compressive strength. The relationship between the test results using the two methods and compressive strength of concrete is analysed, respectively. The correlation between the ultrasonic pulse velocity and compressive strength of concrete is Vp = 2178·7Fck0·1949, and the relative error range is 4·37%. The correlation between the surface wave velocity and compressive strength of concrete is VR = 902·41, Fck0·2487, and the relative error range is 6·07%. Regression analysis shows that the correlation between the ultrasonic pulse velocity and surface wave velocity is VR = 0 · 8635 VP - 1562, and the relative error range is 2·57%. Multiplexing of the...

The safety of concrete slab was evaluated based on the floor vibration impact sound. The research of high dependability was accomplished for appraisal of floor vibration form applying evaluation standard of serviceability of Reiher/Meister with Koch and evaluation standard of vibration of ISO and AIJ. Test of twice was using different accelerometers, and it was accomplished such as FFT from comparative analysis of the vibration standard. Result of vibration impact sound measurement, peak displacement of Test 1 is in the range of 0.00869∼0.02540 mm, the value of peak frequency is in the range of 18∼27 Hz, average is 22 Hz. The peak acceleration value of Test 2 is in the range of 0.47∼1.07%g, the value of peak frequency is 18.5∼22.57 Hz, average is 21 Hz. The vibration was apparently recognizable in most cases, according to the Reiher/Meister and Koch. Evaluation of serviceability is following the vibration standard and residential appraisal guidelines provided by of ISO and AIJ.

In this study, an experimental research for estimation of slab depth, column size and location of rebar of concrete specimen is conducted using the Impact Echo (IE) method based on stress wave among non-destructive test methods. Estimation of slab depth had a total length of 1800 × 300 mm and six different depths, including 150, 180, 210, 240, 270 and 300 mm. The concrete column specimen was manufactured by differentiating the size into 300 × 300 × 300 mm, 400 × 400 × 400 mm and 500 × 500 × 500 mm. In the case of the specimen for estimation of rebar, rebar of ∅22 mm was used in a specimen of 300 × 370 × 200 and arranged at 130 and 150 mm from the top to the rebar top. As a result of error rate of slab, depth was overall mean of 3·1%. Error rate of column size was overall mean of 1·7%. Mean error rate of rebar location was 1·72% for top, 1·19% for bottom and 1·5% for overall mean showing relative accuracy.

Recently, natural aggregate resource depletion are being raised due to the pollution issues regarding the construction waste generated during demolition of building deterioration and the supply issues of aggregates. Recycled aggregates are being used as a solution to these issues, but the quality and durability/structural performance issues are the restriction of application. This study conducted a comparative evaluation of bond behaviour according to the reinforcing bar type and substitution rate of recycled coarse aggregate mixed with high strength concrete. That was carried out to verify the applicability of recycled coarse aggregate concrete as a structural member. Seventy-two specimens were manufactured with variables of recycled aggregate substitution rate (0, 30, 50 and 100%), reinforcing bar arrangement direction and reinforcing bar types. The bondstress and the slip relation of reinforcing bar and concrete in high strength concrete using recycled aggregate were found to have little influe...

The purpose of the study is to provide reliable data on high-strength recycled aggregate concrete and basic data for maintaining a structure built with high-quality recycled aggregates. An experimental concrete structure mould with rectangular parallelepiped dimensions of 600×600×200 mm, is prepared to measure the wave velocity of specimens aged 28 days. The ultrasonic pulse velocity was measured for specimens that were aged for 1, 3, 7 and 28 days. In the compressive strength test at a material age of 28 days, the concrete incorporating recycled aggregates show almost the same or slightly lower strength compared with natural aggregate concrete. Using the variables of optimised contact time, the velocity of the compression wave obtained through simulation can be an index to determine non-destructive test reliability and evaluate the applicability.

SK is an 84-year-old woman diagnosed with essential tremor (ET) but no cognitive deficits. In this experiment, we tested the effects of mental rotation (a form of additional cognitive load) during reaching behavior (with the right hand) on the tremor profile of the non-moving left hand. We observed a marked increase in tremor and its variability, as well as the "freezing" of the movement pattern as effects of the cognitive load. These findings imply cognitive-motor overlaps in patients with ET, raising the possibility that the deficits reflect the loss of a common pool of neural resources, despite the heterogeneity of the symptoms of the disorder.

Although the research of plasma-material interaction (PMI) is rather immature comparing the recent success of Korean fusion program, there are several facilities and programs of PMI research in Kor...

1. Isoeugenol (IEG) has been tested for toxicity and carcinogenicity due to high potential for human exposure and the structural resemblance to known carcinogenic allylbenzenes. In order to support the interpretation of toxicity and carcinogenecity study outcomes, a toxicokinetic study was performed in which both sexes of F344 rats and B6C3F1 mice were given IEG as a single intravenous (IV) or gavage administration. 2. Following IV administration, IEG was rapidly eliminated from systemic circulation in both species and sexes. Gavage administration revealed a rapid absorption of IEG with tmax values ≤20 min for both species and sexes. In rats, AUC increased in a greater than dose-proportional manner and Clapp values decreased with increasing dose in both sexes suggesting saturation of IEG metabolism. On the other hand, Clapp values in male mice increased with increasing dose suggesting induction of IEG metabolism although this was not evident in the females. 3. Absolute bioavailability was greater in female rats (19%) than male rats (10%) (p < 0.0001), but was not different between the sexes for mice (28% males; 31% females) (p = 0.2437). The collective toxicokinetic data supported that low bioavailability following administration of IEG was the result of extensive first-pass metabolism.

Why does learning come so naturally for some students and yet is so onerous for others? Why do some students need constant reminders while others get on task right away? Why is it that some student...

1. Methyleugenol (MEG) has been used as a flavouring agent in food, as a fragrance in cosmetic products, and as an insect attractant. MEG was carcinogenic in both rats and mice following gavage administration. In this study we investigated plasma toxicokinetics of MEG in F344 rats and B6C3F1 mice of both sexes following single gavage (37, 75, or 150 mg/kg) and intravenous (IV) (37 mg/kg) administration.2. Following IV administration, MEG was rapidly distributed and cleared from the systemic circulation in both species and sexes. Absorption of MEG was rapid following gavage administration with secondary peaks in the plasma MEG concentration-versus-time profiles. Cmax and AUCT increased and the clearance decreased greater than proportional to the dose in rats and mice of both sexes. In general, rats had higher internal exposure to MEG than mice.3. The results for AUCT and clearance suggest that perhaps the metabolism of MEG is saturated at higher doses tested in this study. Absolute bioavailability followin...

The virtual expansion method of the array aperture was suggested in order to improve the direction-of-arrival (DOA) resolution of coherent signals. But the virtual expansion of a single array has an inherent limit to improve the DOA resolution capability due to spurious peaks at the spatial spectrum. To overcome the limit of this method, the spatial spectrum averaging method of the virtually expanded arrays is proposed. From the simulation results for coherent signals impinging on an uniform circular array, the perfect DOA resolution capability of 100% is achieved at the SNR of more than −5 dB by the Deterministic Maximum Likelihood (DML) algorithm including the proposed method. Meanwhile, the DOA resolution capability of the standard DML algorithm is less than 11% at the SNR of more than −5 dB.

SummaryScab, caused by Venturia nashicola, is one of the most damaging diseases in pear. The development of varieties resistant to scab has long been an aim of Asian pear breeding programmes. The application of molecular markers to select scab-resistant plants will increase the efficiency of breeding programmes. To identify DNA markers linked to the scab-resistance gene named Rvn2 in PS2-93-3-98, the progeny of a cross between PS2-93-3-98 and ‘Yali’ pear was studied. As scab-resistance clearly segregated 1:1 in the F1 progeny, Rvn2 is a single dominant gene. Bulked segregant analysis and amplified fragment length polymorphism (AFLP) analysis were then applied to identify markers associated with Rvn2. Three AFLP markers linked to Rvn2 were identified. Mapping of the markers indicated that the three selected markers, E-AGT/M-CCA234, E-ATT/M-CCG328, and E-GGT/M-TCT217, were located 4.9, 3.2, and 0.8 cM from the Rvn2 locus, respectively. Rvn2 was found to be located in a different linkage group from previousl...

Lead free solderability of pure Sn/Cu finish is investigated in terms of microetch process in printed wiring boards manufacturing. Factors affecting the solderability have been known as whisker, contamination, copper tin intermetallic compound, and the thickness of coating. Lead free solderability, in this paper, is correlated with the surface roughness of Cu film after the microetch process. Solderability is measured by wetting balance technique, and the result shows that the wetting force and the wetting time are negatively correlated with the coefficient of –0˙613. Employing statistical design of experiment, two significant factors, etching time and the mount of Piperidine, affecting the wetting force with respect to the surface roughness of Cu film are successfully identified, and response surface plot for the wetting force is also generated for visual an aid of interaction between the two parameters.

In this article, the authors discuss 4 critical components of mathematics assessment that relate to instruction: (a) teachers need to be knowledgeable about mathematical standards and align them with assessment; (b) assessment should combine formal and informal approaches to obtain a more authentic picture of students' performance and meaningfully evaluate progress; (c) assessment should integrate environmental and instructional adaptations to meet the needs of individual students; and (d) teachers need to establish collaborative partnerships with parents and professionals. To enable educators to become more responsive when assessing students with special needs, the authors provide concrete examples and practical guidelines.

The effects of microstructural variables, including secondary dendrite arm spacing (SDAS), the size of primary α phase, the aspect ratio of eutectic Si particle and the thickness of eutectic wall structure, on tensile behaviour of A356 cast aluminium alloy, were quantitatively identified using linear regression analysis method. For systematic microstructural control of A356 specimen, directional solidification method was used with different solidification rates of 5, 25, 50 and 100 μm s−1 respectively. The linear regression analysis suggests that each microstructural variable affects tensile strength and tensile elongation of A356 cast aluminium alloy in a similar fashion. The change in tensile behaviour with varying microstructural variables in A356 cast aluminium alloy is discussed based on fractographic and micrographic observations.

In magnetically enhanced reactive ion etching (MERIE), it is conventionally understood that the etch rate increases with increasing magnetic field strength (MFS) owing to the increase in plasma density. However, it is uncertain that this can be valid under various plasma conditions. This concern was investigated by applying a statistical experimental design to an etching of aluminium thin films in a chlorine (Cl2) plasma. It was noticeable that five experimental cases were contradictory to the reported MFS effect. The major contributor was estimated to be the dominant effect of ion bombardment. The sensitivity analysis of three significant cases revealed a little interaction between MFS and Cl2 flow. Demonstrated high sensitivity of each contradictory case reveals that the process limitations of MERIE can be circumvented by controlling the process parameters.

The authors examined the effects of learning on the change in the organization of the mechanical and dynamical degrees of freedom in 5 men who performed a ski-simulator task. A 3-dimensional analysis of the motion of the total-body center of mass and the segmental centers of mass (head, torso, thighs, and shanks) over practice showed that the recruitment of mechanical degrees of freedom was strongly influenced by anatomical and task constraints. Principal components analysis of the body segments' motions revealed that practice shifted their relative contributions but did not change the number of principal components. The present findings show that there can be independence in the patterns of change in the mechanical and dynamical degrees of freedom that arise from practice.

The research described in this paper concerns the characterisation of polyurethane and polystyrene foam for use as shock absorbing filling materials in impact limiters for nuclear transport packages. For a comparatively small cylindrical transport package the mechanical properties of the foam material in compression tests, a preliminary determination of the best foam density and its co-relation with other material properties, appropriate selection of polyurethane and polystyrene from the relation between the reaction force due to the drop impact and their compression characteristic properties are discussed.

A high-resolution electron microscope (HREM) has been used to study the interfacial structure of Cu–Nb filamentary composites fabricated by the bundling and drawing process. At the matrix/filament interface, misfit interface dislocations were introduced periodically to relieve the misfit strain. The spacing between interfacial misfit dislocations for the interface between (1 1)Cu and (10 )Nb planes was observed to vary with the local tilt angle of the interface. The moire fringes appeared in association with interfacial dislocations and the spacing between moire fringes was found to be quite close to that between interfacial dislocations.

The structure and mechanical properties of melt spun Al86Ni9Mm5 alloy ribbons in both as solidified amorphous and heat treated nanocomposite conditions were investigated using DSC, XRD, TEM, and Vickers microhardness techniques. Primary crystallisation of the amorphous alloy resulted in the formation of fine nanocrystalline fcc-Al particles embedded in an amorphous matrix forming a nanocomposite. The growth behaviour of the primary fcc-Al particles under isothermal conditions was investigated. The hardness ofthe composite varied with the solute content in the amorphous phase and the microstructure after heat treatment. The hardening in these nanocomposites was quantitatively explained using a rule of mixtures model based on the volume fraction of the amorphous matrix and the Al particles. The nanometre sized particles were treated as perfect materials and the matrix was treated as an amorphousmaterial, in which the solute concentration increased as the volume fraction of the Al particles increase...

Ceramide III was prepared by the cultivation of Saccharomyces cerevisiae. Ceramide III was partitioned from the cell extracts by solvent extraction and analyzed by normal phased high performance li...

X-linked amelogenesis imperfectas (AI) resulting from mutations in the amelogenin gene (AMELX) are phenotypically and genetically diverse. Amelogenin is the predominant matrix protein in developing enamel and is essential for normal enamel formation. To date, 12 allelic AMELX mutations have been described that purportedly result in markedly different expressed amelogenin protein products. We hypothesize that these AMELX gene mutations result in unique and functionally altered amelogenin proteins that are associated with distinct amelogenesis imperfecta phenotypes. The AMELX mutations and associated phenotypes fall generally into three categories. (1) Mutations (e.g., signal peptide mutations) causing a total of loss of amelogenin protein are associated with a primarily hypoplastic phenotype (though mineralization defects also can occur). (2) Missense mutations affecting the N-terminal region, especially those causing changes in the putative lectin-binding domain and TRAP (tyrosine rich amelogenin protein) region of the amelogenin molecule, result in a predominantly hypomineralization/hypomaturation AI phenotype with enamel that is discolored and has retained amelogenin. (3) Mutations causing loss of the amelogenin C terminus result in a phenotype characterized by hypoplasia. The consistent association of similar hypoplastic or hypomineralization/hypomaturation AI phenotypes with specific AMELX mutations may help identify distinct functional domains of the amelogenin molecule. The phenotype-genotype correlations in this study suggest there are important functional domains of the amelogenin molecule that are critical for the development of normal enamel structure, composition, and thickness.

Using the example of Japan's factory-based housing industry where firms supply customized homes which are pre-assembled from standardized components or modular systems, it is argued that ‘mass customization’ can be supported by several generic supply-chain models. The paper discusses these models and provides a case study of a Japanese housing supplier. Conclusions are then drawn on the implications of these lessons for the UK's speculative housebuilding industry.

This paper expands on recent findings that link dynamic patterns of striatal activity with patterns of movement and exploration in wild-type and transgenic mice (R6/2) that model Huntington disease (HD), a fatally inherited neurological condition. Here, with HD as a backdrop, we further develop the concept of entropy conservation in brain and behavior. In particular, we propose that entropy conservation could serve as a rule that guides the process of redistributing brain activity dynamics in order to alter behavior, allowing the adaptation to an ever-changing external environment. This concept is further linked to recent neuroimaging studies in human aging, building a new bridge between our recent findings of entropy conservation and the extant literature.

On 23 July 1995, the oil tanker Sea Prince ran aground near Sori Island, off the South Coast of Korea and spilled 5040 tons of crude and fuel oil into the marine environment. The effects of the Sea Prince oil spill on the marine environment have been investigated since 1996. The main objectives of this study were to find out the residual effects of beached oil and transport of dispersed oil into the subtidal area. Twenty-four PAHs were analyzed and principal component analysis was performed to elucidate weathering status, bioaccumulation pattern, and input sources. There were signs of bioconcentration of oil-derived PAHs in mussels of stranded oil remained sites. However, environmental factors overwhelmed these so that all the bivalves studied showed similar pattern in the last two sampling campaigns. There was no significant evidence of transport of oil-derived PAHs into the subtidal environment. However, one station showed an exceptionally high concentration (923 ng/g dry weight), which implies the limited input of particle-bound PAHs into this confined area.

Metallothionein (MT) is a suitable model for investigating molecular interactions relating to the handling of metals in cells. However, the production of functional MT proteins in microorganisms has been limited because of the instability of MT—the thiol group of cysteine is easily oxidized and proteolysis occurs. To increase the binding ability and to stabilize MT, we designed genes for dimeric and tetrameric MT and the genes were successfully overexpressed in Escherichia coli to generate functional oligomeric MTs. A human MT-II (hMT-II) synthesized with prokaryotic codons, a linker encoding a glycine tripeptide, and Met-deficient hMT-II was ligated to create a dimeric MT, from which a tetrameric MT was then constructed. The increased molecular size of the constructs resulted in improved stability and productivity in E. coli. Cells of E. coli carrying the oligomeric MT genes showed resistance toward Zn and Cd toxicity. The oligomeric proteins formed inclusion bodies, which were dissolved with dithiothrei...

Besides roles in nucleus mediating the condensation of DNA into chromatin, the involvement of histones in autoimmune diseases, hormone regulation, and killing leukemia cells has been reported. In order to investigate the functions of histones on an autoimmune disease, histone H1 was injected into collagen-induced arthritis (CIA) mice. A dramatic suppression of CIA by histone H1 was observed at a dose of 1 mg/kg bodyweight of mouse. In addition, the increased level of anti-inflammatory cytokine IL-10 was detected in cultured splenocytes from the mouse treated with histone H1. These findings suggest that histone H1 suppresses the collagen-induced arthritis, possibly by increasing the level of IL-10 production.

This paper presents the problem of jointly determining the optimum process mean and screening limits for each market in situations where there are several markets with different price/cost structures. All items are inspected prior to shipment, and the inspection is performed on a variable which is highly correlated with the quality characteristic of interest. It is assumed that that quality characteristic is normally distributed with an unknown mean and a known variance. A profit model is constructed which involves selling price, production cost, penalty cost and inspection cost. Methods for finding the optimum process mean and screening limits for each market are presented.

Floc migration in freezing chamber, and the effects on the corresponding sludge chemical compositions are discussed based on the FTIR analysis. The changes in chemical compositions of sludge after freezing is found to strongly correlated with the degree of floc migration. The action of ice front movement is suggested to release some extracellular polymers from the sludge body, with the latter being rejected by the ice crystals. The macro‐migration of sludge flocs is an essential step to change the sludge chemical compositions, and to improve the dewaterability.

The original and the treated activated sludge samples and the ECPs extracted from the original sludge were analyzed via FTIR spectra. A characteristic band near 670 cm‐1 was found to have a strong correlation with the sludge dewaterability and settleability, and was proposed as an indicator for sludge performance. Possible mechanism for freeze/thaw treatment was also discussed.

The performance of two-part, amidoamine-cured epoxy adhesives on clean and oil-contaminated electrogalvanized steel (EGS) was studied using screening and lap shear tests. On exposure to boiling water, the cured epoxy adhesives with amidoamines having higher amine value delaminated from the clean and oil-contaminated EGS surfaces before those cured with amidoamines having low amine value. The results of X-ray photoelectron spectroscopy (XPS) showed that the adhesives cured with amidoamines having high amine value were unable to displace the oil from the EGS substrate. However, the durability and the strength of the adhesive bonds on the oiled EGS could be improved by adding proper amounts of silane or wetting agent to the adhesive. The preferential adsorption of amino curing agents occurred on the clean EGS surface, confirmed by XPS and reflection absorption infrared spectroscopy, and this decreased the durability of the bonds in boiling water. In addition, from XPS analyses of various specimens, ...

Extracellular phospholipase A2 (PLA2) is a proinflammatory enzyme found especially in the inflammatory exudate to modulate blood flow to areas of antigen stimulation. In this study we found that PLA2 exerted a biphasic effect on the proliferation of phytohemagglutinin (PHA)-stimulated human mononuclear cells (PHA MNC). At low concentrations range from 0.001 to 1 U/ml, PLA2 enhanced the proliferation of PHA MNC (maximal increase was 37.0 +/- 5.67%). Conversely, at concentrations over 10 U/ml, PLA2 markedly suppressed the PHA-induced MNC proliferation (maximal decrease was 88.86 +/- 2.89%). PLA2 was non-toxic to lymphocytes after three days culture, unless the concentration was higher than 100 U/ml. The membrane polarization of PHA-stimulated lymphocytes was also increased by PLA2 at a low concentration. In addition, PLA2 displayed a similar effect on the proliferation of streptokinase-streptodornase (SK/SD) or allogeneic cell stimulated lymphocytes. The change of lymphocyte proliferation by PLA2, was parallel to the change of percentage of helper T cells. Furthermore--a CD4-rich population was proved more susceptible to PLA2 effect than a CD8-rich population. Para-bromophenacyl bromide (pBPB), an irreversible inhibitor of PLA2, abrogated the biphasic effect of PLA2 on PHA MNC proliferation. These results suggest that PLA2 plays a regulatory role on immune reactions by modulating the percentage of helper T cells.

Durability of adhesive bonds formed by curing epoxies against oil-contaminated steel substrates using amidoamine curing agents was determined during exposure to boiling water. The most durable bonds were obtained using amidoamine curing agents with relatively low amine numbers and by blending silane coupling agents such as γ-glycidoxypropyltrimethoxysilane (γ-GPS) and N-(2-aminoethyl)-3-aminopropyltrimethoxy silane (AAMS) into the adhesives. When X-ray photoelectron spectroscopy (XPS) was used to characterize the failure surfaces of the adhesive joints after exposure to boiling water, it was determined that adhesives prepared using amidoamine curing agents with low amine numbers were able to displace the oil from the steel surface but adhesives prepared with amidoamine curing agents with high amine numbers were not. Results obtained from XPS also showed that the amino groups on the substrate fracture surfaces of joints prepared using curing agents with low amine numbers were protonated whereas th...

Opinion leaders (OLs) are members within a social group with significant social influence over others. A guideline on urinary catheter care was introduced in three groups (A, B and C) of two randomly allocated wards. Two OLs per ward were identified by nurses in groups A and B, using a sociometric method. For education, inservice lectures for 30% of nurses and OLs tutorials for all nurses were used in group A; OLs tutorials in B, lectures in C and ward nurses were in turn responsible for educating new arrivals of student nurses. Before and after the education programme, the guideline's frequency of practice was assessed by surveying 30% of randomly selected nurses and by direct observation for incorrect practices. A student's quiz on the guideline was also conducted. For all three methods of measurement, the best results were in group A followed by B and C; and the differences for the three groups were significant (p less than 0.05). This indicates that continuing education in the hospital can be effectively conducted by the enlistment of ward OLs.

Despite chronic inflammation and the presence of hypergammaglobulinemia, rheumatoid factor (RF) is rarely found in the blood of patients with ankylosing spondylitis (AS). We used ELISA to compare spontaneous and pokeweed mitogen (PWM)-induced IgG, IgM and IgM rheumatoid factor (IgM-RF) production in normals and in patients with rheumatoid arthritis (RA) and AS. The IgG and IgM synthesis in these three groups did not differ. However, the IgM-RF level in PWM-induced mononuclear cell cultured supernatants of AS was significantly decreased, compared with normal and RA patients. Furthermore, mixing experiments by co-culture of normal T or B cells with patient's B or T cells in the presence of PWM revealed a deficiency of the helper T cell function in patients with AS. These results illustrate the cellular mechanism of the seronegativity of the rheumatoid factor in patients with ankylosing spondylitis.

X-ray photoelectron spectroscopy (XPS) has been used to determine the failure mechanisms in neoprene/steel adhesive bonds during cathodic delamination or during immersion in aqueous solutions of NaOH to simulate the effects of cathodic delamination at the bondline. Delamination of the rubber from substrates that had been pretreated by acid-etching began at the edges of the bonds and proceeded slowly inward. The centers of the bonds were always intact except for every long times when complete delamination of the rubber was observed. Failure was near the primer/oxide interface but with islands of rubber remaining on the substrate and islands of oxide remaining on the rubber. The failure mechanism was associated with degradation of the phenolic primer and with dehydrohalogenation of chlorinated rubber in the adhesive and primer. Dehydrohalogenation resulted in the formation of inorganic salts which could dissolve during exposure to water at high pH values, leading to large osmotic pressures at the i...

We have characterized a strange attractor with a fractal dimension in a fully-developed turbulent channel flow simulated numerically by computing the Lyapunov dimension based on a spatial correlation concept. Our paper presents an example along the line of current discussions whether we can represent an infinite-dimensional dynamical system (fluid flow) by a small finite-dimensional dynamical system. At least for this particular flow under the specified conditions, we can indeed approximate the fluid system by a small-dimensional dynamical system.

The calculated stress-optical coefficients obtained using the rotational isomer model and the principle of additivity of bond polarizability tensors give values of the segment polarizability anisotropy, Δ TSin reasonable agreement with experimental values for swollen rubber networks. Furthermore, these values agree well with those obtained from streaming birefringence studies. Estimates of the effect of ordering in the amorphous state upon Δ TS lead to values appreciably in excess of those found experimentally. The effect of swelling solvent on Δ TS can be interpreted in terms of its role in separating chains from each other and in itself being oriented by the polymer chain. This model accounts for the observation that Δ TS increases with increasing anisotropy of the swelling solvent. The value of Δ TS found for networks swollen with an isotropic solvent is approximately, but not exactly, equal to the intrinsic anisotropy of the segment, Δ TS found for undiluted networks arises in part from mutua...

The expression of the maltase (MALS) and the maltose permease (MALT) genes in Saccharomyces species is coregulated at the transcriptional level; they are coordinately induced by maltose in the presence of a positively acting regulatory (MALR) gene and carbon catabolite repressed by glucose. We generated a series of deletions in the upstream region of the MAL6S gene to examine the regulatory elements in detail. The results showed that inducible expression by maltose was lost when the region between 320 and 380 base pairs upstream of the translation initiation codon was deleted. This region contained an imperfect inverted repeat sequence (-361 to -327) or four copies of short direct repeats that might serve as components of the upstream activation site (UASM) for the maltase gene, or both. When a stretch of T-rich sequence (-253 to -237) was deleted, the susceptibility of the maltase gene to carbon catabolite repression was affected.

The Furfural and 2-furoic acid present in bacterial cultures were extracted and detected by High pressure Liquid Chromatogrphy (HPLC). Using the methanol/water solvent (70/30), the column, μ Bondapak C18 (Waters Associates) seperated these compounds well. The detection was performed at 254 nm where binary mixtures were absorbed. This method provided a rapid and simultaneous detection for the conversion of furfural into 2-furoic acid followed by the utilization of 2-furoic acid during bacterial growth.

Cathodic delamination of neoprene-to-steel adhesive bonds prepared using a proprietary vulcanizing adhesive and primer was investigated using Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Chlorinated rubber in the adhesive and primer was stable during immersion in NaOH solutions simulating the high pH conditions obtained at the bondline during cathodic delamination. However, methylene groups linking phenol moieties in phenolic resins in the primer were rapidly oxidized during immersion in NaOH solutions to form benzophenone linkages which were oxidized further to carboxylic acids and quinones. Chlorine produced by dehydrohalogenation of chlorinated rubber in the adhesive and primer during curing of the neoprene reacted with ZnO in the primer to form ZnCl2 in the bondline. Failure of adhesive bonds between neoprene and steel during cathodic delamination is probably related to oxidation of the phenolic resins in the primer and to osmotic effects related ...