186 research outputs found

    EFFECTS OF TIN ON HARDNESS, WEAR RATE AND COEFFICIENT OF FRICTION OF CAST CU-NI-SN ALLOYS

    Get PDF
    An investigation was carried out to understand the effects of Sn on hardness, wear rate and the coefficient of friction of spinodal Cu-Ni-Sn alloys. Alloys of appropriate compositions were melted in a crucible furnace under argon atmosphere and cast into sand moulds. Solution heat treated and aged specimens were tested for hardness, wear rate and the coefficient of friction. It was found that the hardness increases when the Sn content increases from 4% to 8% in the solution heat treated conditions. The peak aging time is found to decrease with an increase in the Sn content. Further, the coefficient of friction is independent of hardness whereas the wear rate decreases linearly with hardness irrespective of Sn content

    24,4,8-Trioxa-21-aza-1,3,6(1,2)-tri­benzena-2(2,3)-bicyclo­[3.3.0]octa­na­cyclo­octa­phane

    Get PDF
    The crystal structure of the title compound, C26H25NO3, was determined as part of an investigation of host–guest and electron donor–acceptor complexes. The oxazole and the pyrrole rings both adopt envelope conformations. The dihedral angle between the two benzene rings directly linked to the oxazole ring is 49.5 (1)°. The crystal structure is stabilized by a C—H⋯π inter­action

    CFD parametric study of thermal performance of different fruit packaging box designs

    Get PDF
    Air temperature and relative humidity values of cold storage conditions are the major factor affecting the perishability of fresh fruits. The sooner the field heat is extracted from the products and the proper temperature is maintained consistency throughout the cold chain, larger it will be shelf life of these products. Forced air cooling is the most commonly used technique to remove the field heat in post-harvest storage. Energy-efficient and quality-oriented cold storage mainly depends on the time to remove the heat. This time can be reduced by optimizing the configuration of the vent holes of the packaging box, namely it dimension (area), it shape, alignment and position. This paper shows the numerical predictions of air temperature and velocity by a CFD parametric study of eight different vent hole configurations. These configurations consider a packaging box with double wall. The vent holes of each wall have different dimension and shape. The vent holes of both walls can be also aligned or unaligned. The analysis of results aims to determine the best configurations that improve the cooling rate, the airflow and temperature uniformity. The numerical predictions of the air temperature show close values, but three configurations can be identified as predicting the lowest air temperature values with lowest standard deviation. These results may help on the development of new configuration for fruit boxes that promote the extension of the fruits shelflife.(undefined

    Ethyl 2-[N-(2-Formyl­phen­yl)benzene­sulfonamido]acetate

    Get PDF
    In the title compound, C17H17NO5S, the N atom is sp 3-hybridized and the S atom has a distorted tetra­hedral configuration. The dihedral angle between the two aromatic rings is 30.0 (1)°, and that between the ethyl acetate group and the formyl­phenyl ring is 77.4 (1)°. The mol­ecules are linked into chains along [100] by C—H⋯O hydrogen bonds and the chains are linked via C—H⋯π inter­actions

    2,5-Dimethyl-1-phenyl­sulfonyl-1H-pyrrole-3,4-dicarbaldehyde

    Get PDF
    In the title compound, C14H13NO4S, the mean planes of the pyrrole and phenyl rings form a dihedral angle of 88.7 (1)°. The aldehyde groups are slightly twisted from the pyrrole plane. In the crystal structure, mol­ecules are linked into a three-dimensional framework by C—H⋯O hydrogen bonds

    Reuse of textile effluent treatment plant sludge in building material

    Get PDF
    Abstract This study examines the potential reuse of textile effluent treatment plant (ETP) sludge in building materials. The physico-chemical and engineering properties of a composite textile sludge sample from the southern part of India have been studied. The tests were conducted as per Bureau of Indian Standards (BIS) specification codes to evaluate the suitability of the sludge for structural and non-structural application by partial replacement of up to 30% of cement. The cement-sludge samples failed to meet the required strength for structural applications. The strength and other properties met the Bureau of Indian Standards for non-structural materials such as flooring tiles, solid and pavement blocks, and bricks. Results generally meet most ASTM standards for nonstructural materials, except that the sludge-amended bricks do not meet the Grade NW brick standard. It is concluded that the substitution of textile ETP sludge for cement, up to a maximum of 30%, may be possible in the manufacturing of non-structural building materials. Detailed leachability and economic feasibility studies need to be carried out as the next step of research

    Discrepancies in assessing anterior chamber activity among uveitis specialists

    Get PDF
    PURPOSE: To evaluate current practices in anterior chamber (AC) inflammation assessment among uveitis specialists. METHODS: Uveitis specialists were invited to participate in an electronic survey designed to understand their practice in assessing AC inflammation. RESULTS: Sixty-five ophthalmologists participated in the survey. Of them, 69.2 % (n = 45) reported using the current Standardization of Uveitis Nomenclature (SUN) guidelines of a 1 × 1-mm slit beam when grading AC cells. Only 38.5 % (n = 5) reported routinely counting the number of cells. In the management of uveitis, 98.5 % (n = 64) valued flare assessment, but 84.6 % (n = 55) did not use laser flare photometry. In total, 36.9 % (n = 24) agreed that laser flare photometry would change their management, while 16.9 % (n = 11) did not see its usefulness. The remaining participants were undecided. CONCLUSION: A number of issues limit the clinical assessment of AC inflammation. Different classifications are still being used despite efforts to standardize practice. While the value of flare is widely recognized, the role of laser flare photometry remains controversial

    Investigations on the absorption spectrum of TiO2 nanofluid

    Get PDF
    Nanofluids are tailored nano- colloidal suspensions of nanoparticles in a suitable base fluid. This present work investigates the absorption spectrum in TiO2-water nanofluids to identify the potential application of nanofluids in Direct Absorption Solar Collectors (DASC). Nanoparticles of Titanium dioxide (TiO2) are prepared by sol gel and characterized by X Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). TiO2-water nanofluids with weight fraction of 0.1% are prepared by a two-step process with sonication. The prepared nanofluids are investigated for their stability by a gravity sedimentation method and for their optical property by UV-Vis spectroscopy. Stability of nanofluid is essential for the applications of nanofluid in DASC. TiO2 nanoparticles with a crystallite size of 43nm are obtained .The SEM image reveals the agglomerated state of TiO2 nanoparticles and the stability of TiO2 nanofluid is reported as 9-10days. UV results indicate the decrease in absorption from 440-500nm, complete absorption from 500-700nm and increase in absorption from 700-900nm.TiO2 nanofluids are recommended as potential candidates for DASC in UV and IR regions

    Contribution of Cystine-Glutamate Antiporters to the Psychotomimetic Effects of Phencyclidine

    Get PDF
    Altered glutamate signaling contributes to a myriad of neural disorders, including schizophrenia. While synaptic levels are intensely studied, nonvesicular release mechanisms, including cystine–glutamate exchange, maintain high steady-state glutamate levels in the extrasynaptic space. The existence of extrasynaptic receptors, including metabotropic group II glutamate receptors (mGluR), pose nonvesicular release mechanisms as unrecognized targets capable of contributing to pathological glutamate signaling. We tested the hypothesis that activation of cystine–glutamate antiporters using the cysteine prodrug N-acetylcysteine would blunt psychotomimetic effects in the rodent phencyclidine (PCP) model of schizophrenia. First, we demonstrate that PCP elevates extracellular glutamate in the prefrontal cortex, an effect that is blocked by N-acetylcysteine pretreatment. To determine the relevance of the above finding, we assessed social interaction and found that N-acetylcysteine reverses social withdrawal produced by repeated PCP. In a separate paradigm, acute PCP resulted in working memory deficits assessed using a discrete trial t-maze task, and this effect was also reversed by N-acetylcysteine pretreatment. The capacity of N-acetylcysteine to restore working memory was blocked by infusion of the cystine–glutamate antiporter inhibitor (S)-4-carboxyphenylglycine into the prefrontal cortex or systemic administration of the group II mGluR antagonist LY341495 indicating that the effects of N-acetylcysteine requires cystine–glutamate exchange and group II mGluR activation. Finally, protein levels from postmortem tissue obtained from schizophrenic patients revealed significant changes in the level of xCT, the active subunit for cystine–glutamate exchange, in the dorsolateral prefrontal cortex. These data advance cystine–glutamate antiporters as novel targets capable of reversing the psychotomimetic effects of PCP
    corecore