bluuebunny/crossref_metadata_2025 huggingface dataset:
Inheritance of aspartate aminotransferase (AAT) inCucumisspecies as revealed by interspecific hybridization
Authors: Chen Jin-Feng , Ren Gang , Luo Xiang-Dong , Staub Jack , Jahn Molly M.
Published: November 2006

The inheritance of aspartate aminotransferase (AAT) isozymes was investigated in Cucumis sativus L. (CC; 2n = 2x = 14), Cucumis hystrix Chakr. (HH; 2n = 2x = 24), the synthetic amphidiploid species C. hytivus Chen & Kirkbride (HHCC; 2n = 4x = 38), and the allotriploid (HCC; 2n = 3x = 26) from backcrossing C. hytivus to C. sativus. Two polymorphic loci, Aat-1 and Aat-2, and one monomorphic locus, Aat-3, were detected among these parents and their progenies by using polyacrylamide gel electrophoresis. Cucumis sativus displayed the fast-migrating anodic band for Aat-1 (2), while C. hystrix contained a slow-migrating cathodic band (1). For Aat-2, the slow-migrating cathodic band was observed with C. sativus (1), whereas C. hystrix contained the fast-migrating anodic band (2). Cucumis hytivus, a synthetic species derived from doubling the chromosome number of a F1from a C. sativus × C. hystrix mating, exhibited the typical hybrid dimeric banding pattern resulting from the combination of two parental homomeric products with equal staining intensity and a heteromeric product with intermediate mobility and greater staining intensity than either homomeric product. The difference in band intensity between C. hytivus and its backcross progenies, when C. sativus was the recurrent parent, were due to the dosage effects of alleles at Aat-1 and Aat-2. These banding morphotypes can be used for typing of C. hytivus and BC1progenies that are similar in morphology. Aat-3 was monomorphic in this mating, encoding a single allele Aat-3 (1).
Cephalanthera longifolia (Neottieae, Orchidaceae) is mixotrophic: a comparative study between green and nonphotosynthetic individuals
Authors: Abadie Jean-Claude , Püttsepp Ülle , Gebauer Gerhard , Faccio Antonella , Bonfante Paola , Selosse Marc-André
Published: November 2006

We investigated an Estonian population of the orchid Cephalanthera longifolia (L.) Fritsch. (Neottieae tribe), which harbours green and achlorophyllous individuals (= albinos), to understand albino survival and compare mycorrhizal associates, development, and nutrition of the two phenotypes. Albinos never changed phenotype over 14 years and had development similar to green individuals; their chlorophyll content was reduced by 99.4%, making them heterotrophic. Molecular typing by polymerase chain reaction amplification of fungal intergenic transcribed spacer and microscopic analyses showed that Thelephoraceae (Basidiomycetes, usually forming ectomycorrhizae with trees) were mycorrhizal on both phenotypes. Molecular typing also demonstrated that additional fungi were present on roots, including many endophytes (such as Helotiales) and various ectomycorrhizal taxa, whose role and pattern of colonization remained unclear. Mycorrhizal colonization was increased in albinos by about twofold, but no obvious difference in fungal partners compared with green individuals was demonstrated. Analysis of stable isotope composition (N and C) showed that albinos were dependent on their fungi for carbon (mycoheterotrophy), while green individuals recovered 33% of their carbon from fungi (mixotrophy). Surrounding trees, which formed ectomycorrhizae with at least one Thelephoraceae found in orchids, were likely the ultimate carbon source. These data are discussed in the framework of evolution of mycoheterotrophy in orchids, especially in Neottieae.
Amplified fragment length polymorphism analysis reveals three distinct taxa inCarex digitalissect.Careyanae(Cyperaceae)
Authors: Ford Bruce A. , Naczi Robert F.C. , Ghazvini Habibollah , Iranpour Mahmood
Published: November 2006

Unweighted pair-group (UPGMA) cluster, neighbor-joining (NJ), and parsimony analyses using amplified fragment length polymorphism (AFLP) data revealed the presence of three taxa within Carex digitalis Willd. (var. digitalis , var. floridana , var. macropoda ). Even when taxa occur syntopically, genetic distinctiveness is maintained (Hertford Co., North Carolina populations of var. macropoda and var. floridana). Clades or clusters corresponding with vars. digitalis and floridana were well supported in all analyses. However, the var. macropoda clade was poorly supported on most trees. Despite our inability to fully resolve taxon relationships, AFLP data substantiate ongoing morphological and phytogeographic studies that show the presence of additional species diversity within sect. Careyanae and the eastern North American Carex flora.
Cell wall degrading enzymes in fusarium wilt of chickpea: correlation between pectinase and xylanase activities and disease development in plants infected with two pathogenic races of Fusarium oxysporum f. sp. ciceris
Authors: Jorge Inmaculada , Navas-Cortés Juan A. , Jiménez-Díaz Rafael M. , Tena Manuel
Published: November 2006

Production of cell wall degrading enzymes (CWDEs) polygalacturonase (PG), pectate lyase (PL), and xylanase was studied in chickpeas ( Cicer arietinum L. ‘P-2245’) inoculated with Fusarium oxysporum f. sp. ciceris (Padwick) Matuo & K. Sato races 0 (mildly virulent, causing a yellowing syndrome) and 5 (highly virulent, causing a wilting syndrome) by the water-culture method. These CWDEs were similarly produced in both syndromes. PG and PL were the only enzymes occurring in roots and stems and attained the highest specific activity, this being generally higher for race 5 than for race 0. Gel filtration chromatography revealed a similar complement of in planta expressed pectinase isoforms, dominated by an endo-PG and two endo-PLs, the endo-PLs being differentially expressed by the two races. CWDE activities in roots and stems were positively correlated with development of yellowing and wilting. Exceptions to this were PG in stems, which was negatively correlated with the development of yellowing, and PG in roots, which showed a negative trend with development of either syndrome. The levels of CWDEs that significantly correlated with disease development were adequately described by exponential functions of disease progress. Results have implications for the role played by CWDEs in the early and later stages of pathogenesis in chickpea fusarium wilt.
Phylogenetic relationships of Neonectria/Cylindrocarpon on Fagus in North AmericaMention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the US Department of Agriculture.
Authors: Castlebury Lisa A. , Rossman Amy Y. , Hyten Aimee S.
Published: November 2006

The relationship of two species of Neonectria associated with beech bark canker in North America was evaluated by comparing isolates of these and additional species of the Neonectria coccinea (Pers.:Fr.) Rossman & Samuels group found on Fagus. Gene regions in the translation elongation factor 1-alpha (EF1-α), RNA polymerase II second largest subunit (RPB2), and β-tubulin were sequenced and analyzed. Results indicate that the fungus associated with beech bark disease previously known as Neonectria coccinea var. faginata Lohman et al. (≡ Nectria coccinea (Pers.:Fr.) Fr. var. faginata Lohman et al.) should be recognized as a separate species, Neonectria faginata , distinct from Neonectria coccinea . Neonectria faginata including its anamorphic state, Cylindrocarpon faginatum C. Booth, is known only on Fagus in North America. A second species associated with beech bark disease in North America is Neonectria ditissima (Tul. & C. Tul.) Samuels & Rossman, which can be distinguished morphologically from Neonectria faginata based on ascospore size, conidial size and shape, and colony pigmentation. Morphological and molecular data indicate that Neonectria ditissima represents an older name for Neonectria galligena Bres. Similarly, the anamorphic state of Neonectria ditissima is the older epithet Cylindrocarpon heteronema with Cylindrocarpon willkommii as a synonym. Neonectria ditissima occurs on a variety of hardwood trees in North America and Europe. Neonectria coccinea occurs only on Fagus in Europe. Neonectria major (Wollenw.) Castl. & Rossman is recognized as a species that occurs only on Alnus in Canada (British Columbia), France, Norway, and the United States (Washington). The following nomenclatural changes are proposed: Neonectria faginata comb. and stat. nov., Neonectria fuckeliana comb. nov., Neonectria hederae comb. nov., Neonectria major comb. and stat. nov., and Neonectria punicea comb. nov.
New species ofLancisporomyces, Orphella, andParamoebidium, endosymbionts of stonefly nymphs from streams in Nova Scotia, Canada
Authors: Strongman D.B. , White Merlin M.
Published: November 2006

Trichomycetes are endobionts that include both fungal and protistan species living in the guts of aquatic insects. Although widely distributed around the world, the biodiversity of these fungi in Canada is virtually unknown. We report the occurrence of 13 species of trichomycetes associated with stonefly nymphs in the families Capniidae, Leuctridae, Nemouridae, and Taeniopterygidae from collections spanning 8 years. This paper extends the geographical range for a number of known fungal species. We describe four new species of Harpellales, Lancisporomyces anguilliformis, Lancisporomyces falcatus, Lancisporomyces nemouridarum, and Orphella dalhousiensis, including both asexual and sexual features for each, as well as two new species of Paramoebidium (Amoebidiales), Paramoebidium cassidula and Paramoebidium stipula. The observations on zygospore morphology in Lancisporomyces and ontogeny of sexual spores in Orphella broaden our perspective on sexual reproduction in the Harpellales. Also highlighted are data on temporal aspects of species occurrence, asexual and sexual sporulation for some species that show host specificity as well as synchrony in maturation of the endobionts with their stonefly hosts.
Photosynthetic downregulation in the conifer Metasequoia glyptostroboides growing under continuous light: the significance of carbohydrate sinks and paleoecophysiological implications
Authors: Equiza M. Alejandra , Day Michael E. , Jagels Richard , Li Xiaochun
Published: November 2006

During the Eocene (ca. 45 Ma) a temperate climate at high northern latitudes provided an environment unlike any that currently exists on Earth. The growing season was characterized by long (up to 4 months) periods of continuous, low- to moderate-intensity illumination. While this remarkable light regime offered opportunities for substantial growth, it also imposed physiological challenges consequential to potential carbon sink–source imbalance and resulting downregulation of photosynthetic capacity. To better understand the physiology of adaptation to a continuous-light (CL) environment, we experimentally investigated the effects of CL and carbon sink–source relationships in the deciduous conifer Metasequoia glyptostroboides Hu et Cheng, an extant representative of a genus that was the dominant tree component of many Eocene high-latitude forests. We tested the importance of branch-level and whole-plant sinks in curtailing feedback inhibition and the specific roles of starch and sugars in that process using manipulative experiments. Trees growing under either normal day–night cycles or continuous illumination were subjected to reduction of local, branch-level sinks or both local and whole-tree sinks. Reduction in sink strength led to downregulation of photosynthetic capacity, as evidenced by reduction of photosynthetic rates, carboxylation capacity, and electron transfer capacity. Our results suggest that photosynthetic downregulation is minimized by maintenance of both whole-tree sinks and local sinks. downregulation showed a greater correlation with starch than with sugar content, and ultrastructural evidence indicated that foliar starch accumulated only in chloroplasts, and was accompanied by reduction in functional chloroplast grana, but showed no evidence of physical disruption of thylakoids.
Identification of conserved regions in the plastid genome: implications for DNA barcoding and biological function
Authors: Presting Gernot G.
Published: November 2006

All oligonucleotides of the sugarcane chloroplast genome that are conserved in one or more of 36 other completed plastid genomes have been identified by computer-assisted sequence comparison. These regions are of interest because they (i) are indicative of strong selection pressures to maintain specific nucleotide sequences that may yield insights into plastid biology and (ii) can be used as priming sites for amplifying intervening sequences that represent potential DNA barcodes for species identification. The majority of conserved sites are located in the inverted repeat (IR) region, but several sites in the single copy region (predominantly in tRNA and psa/psb genes) are conserved among chloroplasts of all higher plants examined here. Of particular interest are protein coding regions that have been conserved at the nucleotide level, as these may be involved in transcript regulation. This analysis also provides the basis for rational design of a DNA barcode for plastids, and several potential barcode regions have been identified. In particular, two oligonucleotides of length 33 and 25, and separated by approximately 362 nucleotides, are found in all cyanobacteria, red, brown and green algae, as well as diatoms, euglenids, apicomplexans and land plants that have been examined to date. Their widespread occurrence makes the intervening sequence a universal marker for all photosynthetic lineages. Analysis of 160 GenBank accessions illustrates that this region discriminates many algae at the species level, but lacks sufficient variation among the more recently diverged land plants to serve as a single DNA barcode for this taxon. However, this marker should be particularly useful for the DNA barcoding of algal lineages and lichens, as well as for environmental sampling. More rapidly evolving regions of the plastid genome also identified here serve as a starting point to design and test barcodes for more narrowly defined lineages, including the more recently diverged angiosperms.
FABRICATION OF BONE LIKE COMPOSITES MATERIAL AND EVALUATION OF ITS OSSIFEROUS ABILITY
Authors: HISAMORI NORIYUKI , KIMURA MEGUMI , MORISUE HIKARU , MATSUMOTO MORIO , TOYAMA YOSHIAKI
Published: November 2006

Many kinds of materials are currently used as artificial bone substitutes. Hydroxyapatite (HA), the same as the main inorganic component of bone, is one of commonly used bio-ceramics and has excellent bioactivity and biocompatibility with hard tissues. However, it has problems as the bone filler or bone tissue-engineering scaffold due to low fracture toughness and low degradation rate. Recently, biodegradable materials for bone tissue have been developed to respond the requirement. Collagen, the same as the main organic component of bone, is biocompatible, biodegradable and promotes cell adhesion. A composites associated with HA is expected to have early osteoconduction and bone replacement ability. The present study was to fabricate bone-like composites consist of HA and collagen. Besides the ossiferous ability of the material in vivo is evaluated by using rabbits. Bone-like composites were successfully fabricated in this study, associating the collagen with HA. And the composites presented good osteoconductive and bone replacement potential.
THE STRENGTH OF SUBMICRON-SIZED MATERIALS
Authors: NGAN A. H. W. , WO P. C. , ZUO L. , LI H. , AFRIN N.
Published: November 2006

Recent rapid advancements in nano- and micro-machinery technologies call for an urgent need to understand the mechanical behaviour of materials of dimensions in the sub-micron regime. The initial yield strength of submicron crystals exhibits remarkable statistical scatter as well as dependence upon size and time under load. Submicron-sized materials are also found to creep many orders of magnitude faster than bulk counterparts. In this paper, the recent experimental evidence for these phenomena is reviewed. Theoretical explanation of these phenomena is also discussed. The statistical scatter and time dependence of the yield strength are interpreted by a scaling model derived from atomistic simulations. The results indicate that, within a certain load range, the strength of a sub-micron sized material is not deterministic and can only be described by a survival probability. The much faster creep in the submicron regime is interpreted in terms of the much shorter diffusion length compared to bulk creep.
FATIGUE STRENGTH IMPROVEMENT BY PEENING TREATMENT IN DEGASSING PROCESSED CAST ALUMINUM ALLOYS
Authors: OCHI YASUO , MASAKI KIYOTAKA , MATSUMURA TAKASHI , KUMAGAI YOHEI , HAMAGUCHI TATSUHIKO , SANO YUJI
Published: November 2006

Rotating bending fatigue tests were carried out in order to investigate effects of shot peening and laser peening treatment on fatigue properties of degassing processed cast aluminum alloys. Degassing was useful for decreasing cast defects and increasing the range of fatigue life and fatigue strength at 107 cycles compared with those of non-degassed cast alloys. The shot peening and the laser peening treatments also showed remarkable effects for increasing the resistance of crack propagation behaviors and improving the fatigue strength of the degassing processed cast aluminum alloys.
PRETREATMENT EFFECTS ON THE SURFACE CHEMISTRY AND MORPHOLOGY OF ALUMINIUM
Authors: WITHY B. , HYLAND M. , JAMES B.
Published: November 2006

Chemical pretreatments are often used to improve the adhesion of coatings to aluminium. XPS and AFM were used to study the effect of these pretreatments on the surface chemistry and morphology of Al 5005. Four pretreatments were investigated, an acetone degrease, boiling water immersion, and two sulphuric acid etches, FPL and P2. Degreasing had no affect on surface morphology and simply added to the adventitious carbon on the surface. Boiling water immersion produced a chemically stable pseudo-boehmitic surface that was quite porous. The acid etches produced porous pitted surfaces similar to each other but significantly different to the other surfaces. The surface chemistry of the acid etched surfaces was variable and dependant on atmospheric conditions on removal from etch due to the very active surface that the etch produced.
EFFECT OF HOT ISOSTATIC PRESSING ON MECHANICAL PROPERTIES OF Fe41Cr15Mo14C15B6Y2Co7 BMG
Authors: CHEN QINGJUN , ZHANG DELIANG , SHEN JUN , FAN HONGBO , SUN JIANFEI , LIU ZHIGUANG
Published: November 2006

Fe -based bulk amorphous rods of 3 mm in diameter and a composition of Fe 41 Cr 15 Mo 14 C 15 B 6 Y 2 Co 7 were produced by copper mold casting. The as-cast amorphous rods contain a small (2%) fraction of pores. To close the pores, samples cut from the amorphous rods were hot isostatically pressed (hipped) at 863 K, which is in the supercooled liquid temperature range between the glass transition temperature and the crystallization temperature of the amorphous phase, and under a pressure of 200 Mpa. Microstructure examination of the hipped samples shows that hipping results in an increase of the density of the samples from 7.9 g/cm3 to 8.0 g/cm3, and a decrease of the porosity level from 2% to 1%, and that a very small fraction of unknown crystalline phase form. As a result of these microstructure change caused by hipping, the average room temperature compressive fracture strength of the bulk metallic glass (BMG) decrease from 3500 Mpa to 3000 MPa, while the strain to fracture changes little from 1.5% to 1.4%. The mechanisms of the effect of hipping on microstructure and mechanical properties of the Fe -based BMG are discussed.
RESEARCH ON WATER BASED COATING CONTAINING NANO-SILICA FOR MAGNESIUM ALLOY
Authors: HUANG WEI , ZHENG TIANLIANG , LI DI
Published: November 2006

Due to magnesium's active chemical property, a novel environmental protective water based metallic coating was developed, which mainly contains metal flake, nano-silica, silicate and silane. The coating's properties were investigated by neutral salt spray test, micro-hardness testing, adhesion test and electrochemical technique etc. Meanwhile the coating surface and microstructure was observed by scanning electron microscopy (SEM). Furthermore, the effect of nano silica on the coating was also explored. Results showed that an excellent adhesive, heat-resisting, protective coating for AZ91D magnesium alloy could be achieved by this technique. It also indicated that nano silica could greatly improve the properties of coating. In the paper, mechanism of nano silica coating was also discussed.
EVALUATION OF FRACTURE IN CONCRETE WITH RECYCLED AGGREGATE BY ACOUSTIC EMISSION
Authors: NISHIBATA SAYAKA , WATANABE TAKESHI , HASHIMORO CHIKANORI , KOHNO KIYOSHI
Published: November 2006

This research revealed fracture behavior of concrete in using recycled aggregates by Acoustic Emission as one of the Non-destructive Inspection. The phenomenon of acoustic emission (AE) is the propagation of elastic waves generated from a source, known as a micro-crack in an elastic material. There were taken to use low-treated recycled aggregate, crushed returned ready mixed concrete for aggregate and normal aggregate. Examination measured AE under the uniaxial compression test. The condition of load is repeated loading. As a result, fracture behavior due to low treated recycled aggregate was detected by AE. It is clarified that AE of concrete with low treated recycled aggregate appeared in low stress level. It has been understood that difference of aggregates becomes clear from Kaiser effect in repeated loading. In relation between RA value and average frequency, it has been understood the adhesion properties of the cement paste in recycled aggregate are appreciable.
DAMPING PERFORMANCE AND MECHANISM OF HIGH STRENGTH ALUMINUM ALLOY PREPARED BY RAPIDLY SOLIDIFIED/POWER METALLURGY PROCESS
Authors: YAO JUNCHEN , ZHAO HAITAO , YU LIMING , MA YUE , LI YAN , XU HUIBIN
Published: November 2006

The investigation of damping property, microstructure and damping mechanism of High Strength Aluminum Alloy (HSAA) prepared by rapid solidified/powder metallurgy (RS/PM) process were conducted by means of Dynamic Mechanical Thermal Analyzer (DMTA) and Transmission Electron Microscopy (TEM) in the paper. The damping capacity (Q-1) of the HSAA was (0.5~3.1)×10-2 in the temperature range of 20~250°C, reaching to the level of high damping alloys. It was found that grain boundaries in the alloy became clear and sharp in high temperature and contributed to the total damping capacity. The analysis results show that at low temperature, the main internal friction mechanism was dislocation damping which was induced by large extrusion deformation, while in the high temperature region, the influence of interface damping increased gradually.
THE INFLUENCE OF ANODIZED FILM ON CORROSION BEHAVIOR OF MAGNESIUM ALLOYS
Authors: BAI LIQUN , GUO MIN , LI DI , QIAN JIANGANG , GUO BAOLAN
Published: November 2006

The influence of anodized film on corrosion and electrochemical behavior of extruded magnesium alloy AZ63, cast and die-cast magnesium alloys AZ91D were investigated by using immersion technique, electrochemical methods, SEM, EDAX, IR and XRD. The results showed anodized film could improve remarkably corrosion resistance. Protection effect was different with the same anodizing process because formation status of anodized film of different materials was different. The formation status of anodized film was related to alloy microstructure as revealed by optical and scanning electron microscopy. The formatting process and casting method strongly influences the corrosion performance by affecting on the alloy microstructure. A tentative corrosion mechanism is presented explaining the corrosion behavior of anodized magnesium alloy.
EFFECTS OF PROCESSING PARAMETERS ON THIXOFORMABILITY AND DEFECTS OF AZ91D
Authors: LI YUANDONG , MA YING , CHEN TIJUN , XU WEIJUN , GAO WEI
Published: November 2006

The thixoformability and defect formation of AZ91D magnesium alloy are studied with different processing parameters including reheating temperature, time and die temperature. The results indicated that the suitable processing parameters should be reheating temperature between 575-595°C, reheating time more than 75 min, and die temperature over 275°C. Four types of defects, coldshut, liquid segregation, microporosity and cracks, have been observed in the thixoformed products if the processing parameters are not controlled properly. Among these defects, microporosity and cracks are always dominant.
DEGRADATION OF CARBON FIBER/EPOXY COMPOSITES BY XE LAMP AND HUMIDITY
Authors: LV XIAOJUN , ZHANG QI , XIE GUOJUN , LIU GUANJIE
Published: November 2006

In order to understand the effect of natural environmental factors on the carbon fiber/epoxy composites, the degradation of carbon fiber/epoxy composite was studied. The specimens were exposed in a Xe lamp chamber and suffered to ultraviolet light radiation, temperature and/or humidity conditions. The results show that the radiation, temperature and/or humidity could cause extensive corrosion to the surface and interior of the carbon/epoxy composite and attack the interface between matrix and carbon fiber, resulting in an obvious reduction of the transverse tensile strength and interlaminar shear strength. On the contrary, the longitudinal transverse shear strength was not affected much by the radiation, temperature and/or humidity. The results indicate that the radiation, temperature and/or humidity can result in the corrosion of the carbon/epoxy composite and consequently affect the mechanical properties of the carbon/epoxy composite partially.
APPLICATION OF A NEW MEASURING METHOD USING AN OPTICAL FIBER STRAIN SENSOR TO AN UNDERGROUND TUNNEL
Authors: FUKURO ATSUSSHI , TORIGOE TOSHIHIKO , MIZUGUCHI HIROYUKI , UEDA TAKAO
Published: November 2006

The measuring methods using optical fiber strain sensors are being considered as structural monitoring technologies for concrete structures. B-OTDR method using optical fiber strain sensors can measure continuous strain along an optical fiber over 80km. Because of this advantage, it is expected to measure deformations in large-scale structures. But, this new measuring method, B-OTDR method, is just in development. There is very few case of applying this measuring method to actual structures.

This paper describes a new measuring method using optical fiber strain sensors (B-OTDR method) applying to an actual concrete underground tunnel which was expected to deform by new shaft work near this tunnel. As a result, this method using optical fiber strain sensors can measure the deformation of the underground tunnel.
EFFECT OF FINE PARTICLE BOMBARDMENT TEMPERATURE ON THE SURFACE CHARACTERISTICS OF Ti-6Al-4V ALLOY
Authors: KAMEYAMA YUTAKA , KOMOTORI JUN
Published: November 2006

In this study, we performed Fine Particle Bombardment (FPB) treatment on Ti -6 Al -4 V alloy surfaces at room temperature, high temperature and low temperature. Treated surface were characterized with surface microstructure, hardness and diffusion phenomena. Diffusion was slightly accelerated in higher temperature and inhibited in lower temperature compared to the room temperature. These phenomena agree with the physical laws of diffusion. Hardness increased extremely in the higher temperature treated specimen. This result suggests that higher temperature treatment improves mechanical properties of the substrate surface. Consequently, processing temperature greatly affects mechanical properties of treated surface and diffusion phenomena induced in the FPB treatment.
APPLICATION OF DESALINATION WITH CFRP COMPOSITE ELECTRODE TO CONCRETE DETERIORATED BY CHLORIDE ATTACK
Authors: YAMAGUCHI KEISUKE , UEDA TAKAO , NANASAWA AKIRA
Published: November 2006

As a new rehabilitation technique for recovery both of loading ability and durability of concrete structures deteriorated by chloride attack, desalination (electrochemical chloride removal technique from concrete) using CFRP composite electrode bonding to concrete has been developed. In this study, basic application was tried using small RC specimens, and also application to the large-scale RC beams deteriorated by the chloride attack through the long-term exposure in the outdoors was investigated. As the result of bending test of treated specimens, the decrease of strengthening effect with the electrochemical treatment was observed in the case of small specimens using low absorption rate resin for bonding, on the other hand, in the case of large-scale RC beam using 20% absorption rate resin for bonding CFRP composite electrode, enough strengthening effect was obtained by the bending failure of RC beam with the fracture of CFRP board.
BASIC STUDY OF CONCRETE MADE USING ASH DERIVED FROM THE INCINERATING SEWAGE SLUDGE
Authors: SASAOKA NOBUTAKA , YOKOI KATSUNORI , YAMANAKA TAKASHI
Published: November 2006

Sewage sludge incinerated ash is discharged as waste. Those are increasing with progress of a sewage enterprise every year. However, the reservation of the last disposal place for reclaiming the generated incineration ash is becoming quickly difficult. In this situation of sewage sludge processing, it is very important to promote more reducing and development of new reusing method. Recently, in the construction industry, reusing technology that was used sewage sludge incinerated ash as aggregate for concrete products is developed. But there are many unknown points in the performance and durability of concrete.

In this study, sewage sludge incinerated ash is used instead of natural aggregate for concrete. It is investigated about fresh characteristics, chloride content, strength, resistance to frost damage and drying shrinkage of concrete using sewage sludge incinerated ash. As the results of this research, the compressive strength increases with ratio of sewage sludge incinerated ash. And the relationship between the compressive strength and the dynamic modulus of elasticity can be comparatively expressed as the linear relationship. If this concrete includes proper air content, the resistance to frost damage is enough. The drying shrinkage is become larger with increase of substitute rate of sewage sludge incinerated ash.
COMPENSATION OF ENVIRONMENT AND MOTION ERROR FOR ACCURACY IMPROVEMENT OF ULTRA-PRECISION LATHE
Authors: KWAC LEE-KU , KIM JAE-YEOL , KIM HONG-GUN
Published: November 2006

The technological manipulation of the piezo-electric actuator could compensate for the errors of the machining precision during the process of machining which lead to an elevation and enhancement in overall precisions. This manipulation is a very convenient method to advance the precision for nations without the solid knowledge of the ultra-precision machining technology. There were 2 divisions of researches conducted to develop the UPCU for precision enhancement of the current lathe and compensation for the environmental errors as shown below; The first research was designed to measure and real-time correct any deviations in variety of areas to achieve a compensation system through more effective optical fiber laser encoder than the encoder resolution which was currently used in the existing lathe. The deviations for a real-time correction were composed of followings; the surrounding air temperature, the thermal deviations of the machining materials, the thermal deviations in spindles, and the overall thermal deviation occurred due to the machine structure. The second research was to develop the UPCU and to improve the machining precision through the ultra-precision positioning and the real-time operative error compensation. The ultimate goal was to improve the machining precision of the existing lathe through completing the 2 research tasks mentioned above.
SYMMETRIC AFM CANTILEVER FOR MECHANICAL CHARACTERIZATION OF Mo THIN FILM
Authors: LEE HAK-JOO , KIM JAE-HYUN , CHO KIHO , KANG JAE-YOON , BAEK CHANG-WOOK , KIM JONG-MAN , CHOA SUNG-HOON
Published: November 2006

We have developed a novel method and device for measuring the mechanical properties of micro/nano structures. An atomic force microscope (AFM) was employed to sense applied force and displacement and a new AFM cantilever which overcame the critical problems associated with conventional AFM cantilever systems was fabricated using single crystal silicon (110). The symmetrically designed cantilever removed lateral motion of the probe during indentation and strip bending tests. Strip bending tests on fixed-fixed molybdenum ( Mo ) strips 1 μm in thickness using the assembled cantilever in AFM system showed that consistent load-displacement curves can be obtained. The effect of adhesive energy on mechanical tests in micro/nano-scale was revealed.
EFFECT OF TEST TEMPERATURE ON THE CHARACTERIZATION OF MELT INFILTRATEDSiC/SiCCOMPOSITES
Authors: LEE SANG-PILL , LEE JIN-KYUNG , SHIN YUN-SEOK , BAE DONG-SU , LEE JONG-BACK , KOHYAMA A.
Published: November 2006

The high temperature property of SiC/SiC composites fabricated by the melt infiltration (MI) process has been investigated. SiC/SiC composites reinforced with BN/SiC double coated Hi-Nicalon SiC fibers were fabricated by infiltrating molten silicon into a braiding fibric preform containing C and SiC particles. The mechanical properties of MI- SiC/SiC composites were carried out at the elevated temperatures using the three point bending test. The microstructure of MI- SiC/SiC composites was examined by means of SEM and EDS. The matrix region of MI- SiC/SiC composites represented the chemical fluctuation depending on the composition ratio of Si and C elements. The flexural strength of MI- SiC/SiC composites greatly decreased at the temperatures higher than 1100 °C, due to microstructural instabilities such as interfacial debonding and matrix oxidation.
CHARACTERISTICS OF LOW TEMPERATURE PECVD SILICON NITRIDE FOR MEMS STRUCTURAL MATERIALS
Authors: HUANG H. , SUVOROVA A. , WINCHESTER K. J. , DELL J. M. , FARAONE L.
Published: November 2006

Materials and mechanical characteristics of the low temperature PECVD silicon nitrides have been investigated using various analytical and testing techniques. TEM and SEM examinations reveal that there is no distinct microstructural difference existing between the films deposited under different conditions. However, their mechanical properties determined by nanoindentation indicate otherwise. The variations in mechanical properties with deposition conditions are found to be strongly correlated to the change in silicon-to-nitrogen ratio in the film.
PIEZOELECTRIC PROPERTIES OF PZT FILMS PREPARED BY HYDROTHERMAL METHOD
Authors: FUJIWARA NOBUYOSHI , KUSUKAWA KAZUHIRO , ABDUL RAZAK KHAIRUNISAK , GAO WEI
Published: November 2006

Lead zirconate titanate (PZT) thin films of 5 μm thick were produced by a hydrothermal method on pure titanium substrates. ZrOCl 2-8 H 2 O , Pb ( NO 3)2 and TiO 2 were used as precursors and KOH as a promoter. The hydrothermal synthesis of PZT includes nucleation and crystal growth processes at 120°C or 140°C. The crystallization states were investigated by using scanning electron microscopy and X-Ray diffraction. Piezoelectric properties were evaluated from unimorph cantilever type actuators made of the films. The relationships between the deflection of the actuator due to piezoelectric transverse effect and applied electric field in the direction of thickness of the films showed good linearity. The output voltage from the films under cyclic compressive loading increased with increasing loading frequency, and is saturated at 10 Hz. The PZT films produced by the present methods are satisfactory as a smart material, and are better than the films produced using TiCl 4 as Ti precursor.
STRUCTURAL MODELING AND SIMULATION OF MINIATURIZED MACHINE TOOL: 3-AXIS VERTICAL MICRO-END-MILLING SYSTEM
Authors: WANG WEI , KWEON SUNG-HWAN , KIM IN , YANG SEUNG-HAN
Published: November 2006

The emphasis on structural design of miniaturized machine tool (mMT) used in micro-machining process is different from that of conventional machine tool due to requirement of higher precision and stable performance. In this paper, structural modeling and simulation of 3-axis vertical micro-end-milling system is presented. Based on different components combination, three models of linear multi-degree-of-freedom vertical milling systems are constructed theoretically using high precision stages. The most suitable model is chosen by volumetric error calculation. Finite element method (FEM) is used for simulation of those numerical solid models. Static and dynamic analysis with different joint stiffness and loads is simulated by ANSYS. Prototype model is assembled according to the selected structure. Finally, surface roughness of the bottom of micro slots, which are machined by prototype model, is analyzed to verify the performance of mMT.
INFLUENCE OF ION BOMBARDMENT ON CRITICAL LOAD OF CrN FILM DEPOSITED ONTO ALUMINUM ALLOY BY ARC ION PLATING METHOD
Authors: YONEKURA DAISUKE , MURAKAMI RI-ICHI
Published: November 2006

To improve the adhesive strength between the film and substrate, ion bombardment is frequently performed before the deposition of thin film coatings. In this study scratch tests were carried out on aluminum alloy protected with CrN film coated by arc ion plating method. In order to investigate the influence of ion bombardment conditions on the adhesive strength between the aluminum alloy substrate and the CrN coating, the ion bombardment process was performed before CrN coating under several different bias voltages. The properties near the interface were analyzed using SIMS. As a result, the ion bombardment process had an optimum condition and excessive bias voltage reduced the critical load. A Cr rich layer forms near the substrate surface by implantation of Cr ions due to the high incident energy ions. The Cr rich layer is shallow for the high critical load sample, while the low critical load sample has a deep Cr rich layer. It appears that the adhesion strength between the substrate and the film will depend on the depth or intensity of this Cr rich layer.
PRESSURELESS SINTERING AND HOT ISOSTATIC PRESSING OF Ti3Al-Al2O3 INTERPENETRATING COMPOSITES
Authors: HAN CHING ZEN , ZHANG DELIANG , BROWN IAN
Published: November 2006

Interpenetrating phase Ti 3 Al - Al 2 O 3 composites have been fabricated by reaction sintering of composite powders containing Al and TiO 2 discus milled for two hours using carefully controlled heat-treatment in non-oxidizing atmospheres. Pressureless sintering has been carried out in argon at temperatures between 1330°C and 1480°C and a heating rate of 5°C/min prior to hot isostatic pressing at 200MPa for two hours at 1350°C. Densification of the composites was investigated as a function of temperature before and after hot isostatic pressing. The microstructure development and mechanical properties such as Vickers hardness of near fully dense Ti 3 Al - Al 2 O 3 composites fabricated by sinter-HIP of Al - TiO 2 composite powder were examined. An increase in Vickers hardness was observed after hot isostatic pressing, which can be attributed to the decrease of closed porosity in the composites. Vickers hardness of 11.0±1.0 GPa was achieved for the near fully dense composite produced by pressureless sintering at 1480°C, while 12.6±1.0 GPa was achieved for the near fully dense composite further subjected to hot isostatic pressing.
FTIR STUDY ON MOLECULAR CONTAMINATION ON SURFACE OF OPTICAL MATERIALS
Authors: KATOH MASAHIRO , OKANO NOBUAKI , HORIKAWA TOSHIHIDE , TOMIDA TAHEI , ITOH NOBUNARI
Published: November 2006

The IR spectra of the molecular contaminants on surface of optical materials were measured. The optical disks used were SiO 2, BK7 ( SiO 2 70%, B 2 O 3 10%, K 2 O 8%, N 2 O 8%), CaF 2, ZnSe and Al 2 O 3. N 2, O 2, H 2 O , and CO 2 were adopted as contamination gases. IR spectra of H 2 O (2.7kPa) on BK7 at 373K showed two absorption bands ( OH stretching vibration: around 4000cm-1-3500cm-1 and OH bending vibration: around 2000cm-1-1500cm-1). The absorption intensity decreased with a decrease in temperature and a new band (around 3250cm-1) appeared at 173K. The new band was attributed to phase transition of H 2 O . These phenomena were also observed on the other three discs, except for SiO 2. IR spectra of SiO 2 showed OH stretching band (3676cm-1). The absorption intensity decreased with a decrease in temperature. But two new bands (3720cm-1 and 3620cm-1) appeared under an atmosphere of N 2 (66.5kPa), O 2 (66.5kPa), H 2 O (2.7kPa) or CO 2 (0.7 or 13.3kPa). A similar phenomenon was also observed for BK7, which has OH group. These results suggested the functional group of SiOH interacted with contamination molecules.
CHARACTERIZATION OF PALLADIUM AND PALLADIUM-SILVER ALLOY LAYERS ON STAINLESS STEEL SUPPORT
Authors: KATOH MASAHIRO , SONDOH AKIRA , HORIKAWA TOSHIHIDE , TOMIDA TAHEI
Published: November 2006

Pd and Pd/Ag layers were prepared by a technique of electroless plating on stainless steel supports. To form Pd/Ag layers, Pd layer was plated on an activated stainless steel (SS) sheet followed by Ag plating. The Pd/Ag -SS sheet composite was annealed at 873 K-973 K for 10 h -12 h in helium. Before annealing, the thickness of Pd layer and Ag layer on Pd/Ag -SS sheet composite was 7.6 μm and 1.9 μm, respectively. The formation of Pd/Ag alloy was observed on the SS sheet after annealing at 873 K for 12 h in helium. The ratios of Ag /( Pd + Ag ) were 0.28 on the surface by XRF and 0.29 in the bulk by XPS. This result showed the formation of homogeneous Pd/Ag alloy on the SS sheet at that annealing condition. Helium permeances were measured at a pressure difference of 1 atm and room temperature. The permeances of porous stainless steel (PSS) tubes without and with 78 μm Pd layer were 100 m3/m2h and 0.35 m3/m2h, respectively. This result showed the obtained membrane was an almost dense membrane.
THREE DIMENSIONAL FINITE ELEMENT SIMULATION OF THE FRETTING WEAR PROBLEMS
Authors: LEE CHOON YEOL , BAE JOON WOO , CHOI BYUNG SUN , CHAI YOUNG SUCK
Published: November 2006

The structural integrity of steam generators in nuclear power plants is very much dependent upon the fretting wear characteristics of Inconel 690 U-tubes. In this study, a finite element analysis was used to investigate fretting wear on the secondary side of the steam generator, which arises from flow-induced vibrations (FIV) between the U-tubes and supports or foreign objects. Two-dimensional and three-dimensional finite element analyses were adopted to investigate the fretting wear problems. The purpose of the two-dimensional analysis, which simulated the contact between a punch and a plate, was to demonstrate the validity of using finite element analysis to analyze fretting wear problems. This was achieved by controlling the value of the wear constant and the number of cycles. The two-dimensional solutions obtained from this study were in good agreement with previous results reported by Strömberg. In the three-dimensional finite element analysis, a quarterly symmetric model was used to simulate tubes contacting at right angles. The results of the analyses showed donut-shaped wear along the contacting boundary, which is a typical feature of fretting wear.
SYNTHESIS OF DIAMOND FILMS ON MOLYBDENUM SUBSTRATE SURFACE BY COMBUSTION FLAME
Authors: TAKAHASHI MAMORU , KAMIYA OSAMU , OHYOSHI TADASHI
Published: November 2006

Diamond films were synthesized on a Mo substrate using combustion flame. During the cooling process, most diamond films delaminated. From previous work it was shown that diamond films delaminated at a synthesis temperature less than 1300K (low temperature), and films did not delaminate at synthesis temperature more than 1400K (high temperature). In this study, to clarify the influences on the delamination of the interface, films synthesized at high temperature and low temperature were investigated by SEM and X-ray diffraction. The results show that in the case of low temperature, diamond films were synthesized on the Mo substrate, case of high temperature, Mo 2 C and diamond phases were synthesized on the Mo substrate. Thermally induced interfacial stress occurs due to the thermal expansion mismatch between the synthesized film and the Mo substrate. The interfacial stress by high temperature and low temperature was determined as the cause of the delamination. Thus, the interfacial stress of each synthesized temperature was calculated by a finite element method. The results show that the interfacial stress in the film synthesized by high temperature was smaller than that by the low temperature. As the buffer phases prevent the delamination, synthesized films by high temperature will be useful as hardcoating layer for a metal surface.
DIAMOND AND METAL BONDING BY ACTIVE SOLDER FOR MICRO – CUTTING WIRE
Authors: KAMIYA OSAMU , TSUJI DAIZUKE , ASHIHARA FUMIO , TAKAHASHI MAMORU , ISHIKAWA TADAO , CHEN ZHAN WEN
Published: November 2006

A new method of bonding diamond to metal with active solder has been developed. This method was then used for making micro-cutting wire saws capable of cutting composite materials with high hardness. This cutting process is an environmentally friendly process, as diamond grains loss and hence pollution is minimum. The active solder contained titanium hydride ( TiH 2). Titanium hydride dissociates to atomic Ti and H at high temperatures improving wetting between the solder metal and diamond grains and hence high bonding strength can be obtained. An example of using the new wire for cutting a typical IC chip is given. We believe this environmentally friendly micro-cutting process will be widely used in the future.
EFFECT OF THE SOLUTE REDISTRIBUTION ON THE GROWTH KINETICS IN SOLIDIFICATION
Authors: YAO X.
Published: November 2006

Solute redistribution has been a long-term interest in solidification theoretical study, but its effect on growth rate during solidification is still not completely clear. Models that descript the relationship between growth rate and the alloy concentration remain controversial both qualitatively and quantitatively. This work theoretically analysed and investigated the solute redistribution and its effect on constitutional undercooling during solidification. Systematic analysis on the interaction behaviour between the solid/liquid interface movement and the solute distribution has been performed to clarify the effect of constitutional undercooling on growth rate of solid during solidification. It is demonstrated that the growth rate of crystals conversed to the alloy concentration and the relationship could be quantitatively calculated by the present model by introduction of the interface retardation.
FATIGUE LIFE CHARACTERISTICS OF WATERWORKS PIPE WELDS
Authors: PARK JAE SIL , SEOK CHANG-SUNG , CHOI JUNG HUN
Published: November 2006

The fatigue characteristic of a material or a structure is derived from fatigue tests of standard specimens. However, many test results of standard specimens are very different from those of real structures or components because of geometrical effect, surface condition and so on. In this study, fatigue tests with specimens and pipes were carried out to evaluate the fatigue characteristic of a real waterworks pipe. Standard fatigue specimens and non-standard specimens were extracted from a steel pipe used in waterworks system. Also, fatigue tests of real pipes used in water service were carried out. This result was compared with that of standard specimens and non-standard specimens. To evaluate pipe's fatigue characteristics based on life distribution, the statistical analysis method was introduced. Probability density functions of the specimen based on the normal distribution function were obtained from fatigue tests at particular stress levels. These functions were then transformed to probability density functions based on a specific number of cycles to failure. This procedure was also adapted to the pipe's test results. From these results, the fatigue characteristic of waterworks pipe was evaluated.