157 research outputs found

    Fabrication of Iron Aluminide Coatings (Fe3Al and FeAl3) on Steel Substrate by Self-Propagating High Temperature Synthesis (SHS) Process

    Get PDF
    Iron aluminides (Fe3Al and FeAl3) coatings were fabricated on a steel substrate by self-propagating high temperature synthesis (SHS) method. Raw materials, Fe and Al powders, were mixed at two different stoichiometry ratios (3:1 and 1:3). The mixtures and the substrate were placed in a furnace at 950 °C to ignite the SHS process. Coating phases were investigated using X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). The microstructure of the coatings was analyzed with optical microscopy (OM) and scanning electron microscopy (SEM). The results confirmed that it is possible to produce Fe3Al and FeAl3 coatings on steel substrate using SHS method. In addition, the results show that the coatings were composed of two different phases and their microstructures were non-porous and dense. Wear resistance of the coatings were higher than that of the substrate

    Investigating the Effect of Foliar Applied Proline on the Photosynthetic Pigments Content and Osmolytes of Pistachio Rootstock UCB1 under Water Stress Conditions

    Get PDF
    Introduction  UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little research has been done on this subject. Water stress is one of the most important environmental stresses and occurs for several reasons, including low rainfall, high and low temperatures, salinity, and high intensity of light, among others. Drought stress is a multidimensional stress and causes changes in the physiological, morphological, biochemical, and molecular traits in plants. Proline is also found widely in plants and accumulates in large quantities in response to environmental stresses such as drought. It is the essential amino acids that accumulate in different tissues of the plant, especially in the leaves through the effect of water stress, and that the accumulation of it has a function in the regulation of osmosis in the cell as the proline is increased in the cytoplasm to counterbalance effort osmosis cell sap. Proline is an indicator of water stress tolerance and its increase in the leaf proof that the plant suffered drought stress, also is the way the plant tolerance to drought stress.   Materials and Methods A pot experiment was conducted, to investigate the effectiveness of foliar applied proline in mitigating the concurrent effects of drought stresses on UCB1 rootstock, at greenhouse of Faculty of Agriculture, University of Shahrekord. Experiment was carried out in a completely randomized design with split arrangement having three replications. Chl. and carotenoid contents were determined according to Lichtenthaler (1987). Leaf discs were obtained from expanded leaves of each pot in the morning. The leaf discs were weighed immediately to obtain the fresh weight (FW), and submerged in distilled water for 4 h at 4◦C in dark condition and then weighed to prepare turgor weight (TW). The leaves were dried in a forced-air oven at 70◦C for 24 h, and the dry weight (DW) was recorded. The RWC of samples was calculated using the following equation (Bastam et al., 2012): RWC = [(FW–DW)/(TW–DW)] × 100 Levels of glycine betaine were quantified as described previously by Arakawa et al. (1990). To determine the free-proline concentration, leaves were homogenized in 5 ml of ethanol at 95%. Proline concentration was calculated with a standard curve and expressed as µg g−1fresh mass (Paquin and Lechasseur, 1979).   Results and Discussion The UCB1 proximate analysis in the present study depicted that imposition of drought stress increased the leaf and root proline content and electrolyte leakage. Exogenous application of proline as foliar spray significantly increased the moisture content of leaf and root, RWC, Chl a and total chlorophyll. Exogenous proline application upregulated leaf and root proline contents and decreased the lipid peroxidation (decrease electrolyte leakage), resulting into improvement in chlorophyll contents. 150 mg. l-1 proline application gave maximum alleviation against stress. Numerous reports depict that the exogenous application of proline as a foliar spray can play an important role in enhancing plant tolerance against drought stress, and our results are consistent with them. This ameliorating effect of exogenously applied proline can take the form of osmoprotection, cryoprotection, or protection against reactive oxygen species.For example, in various plant species growing under stress conditions, exogenously supplied proline provided osmoprotection and facilitated plant growth. Normally, proline accumulation in plants, is in response to drought or salinity stress occurs in the cytosol where it contributes substantially to the cytoplasmic osmotic adjustment. It actively takes part in plant osmotic adjustment under stressful environmental conditions. In addition to its role as an osmolyte for osmotic adjustment, it actively takes part to stabilize subcellular structures, biological membranes, proteins, and scavenge free radicals. It also plays a vital role in buffering cellular redox potential under stressful environmental conditions.   Conclusion  In summary, our results showed that, drought induces a decrease in moisture content, RWC, T Chl and carotenoids and an increase in some osmoregulators (proline, glycine betaine, TSC). The most favorable treatment was 150 mg.l-1 proline foliar spray. 150 mg.l-1 proline application gave maximum alleviation against stress. Foliar application increased the moisture content of leaf and root, as well as increased the Chl a, total, RWC and proline content of leaf and root. It can be suggested that the foliar application of proline (150 mg L-1) used as a plants defense factor against drought stress conditions

    The Big Five personality traits and online gaming: A systematic review and meta-analysis.

    Get PDF
    Online gaming has become an essential form of entertainment with the advent of technology and a large sway of research has been undertaken to understand its various permutations. Previous reviews have identified associations between the Big Five personality traits and online gaming, but a systematic review and meta-analysis on the association between these constructs has yet to be undertaken. In the current study we aimed to fill this gap in the literature through a systematic review and meta-analysis comprising of 17 studies and 25,634 individuals (AgeMean = 26.55, males = 75%). The findings showed that agreeableness, extraversion, openness to experience, and neuroticism were not ubiquitously associated with online gaming. The findings showed that only conscientiousness, across samples, had a protective role in online gaming. Furthermore, there were non-significant variations in the Big Five personality traits associations with online gaming when comparing gamers to the general population, younger versus older participants, casual versus 'hardcore' gamers, and high versus low traits (with the exception of neuroticism). As a result of our observations, the underlying mechanisms of individual differences in online gaming remain unclear. Limitations and future directions for research are discussed

    The relationship between five-factor model and diagnostic and statistical manual of mental disorder-fifth edition personality traits on patients with antisocial personality disorder

    Get PDF
    Background: Despite the fact that new criteria of antisocial personality disorder (ASPD) in diagnostic and statistical manual of mental disorders-fi fth edition (DSM-5) were resulted from fi ve-factor model (FFM), there is a small amount of studies that investigate the relations between proposed personality traits and FFM. Also, cross-cultural study in this fi eld continuously would be needed. Th e aim of the present study was to evaluate the relation between the FFM and DSM-5 ASPD pathological traits. Materials and Methods: Th is study was a crosssectional study design. Th e participants consisted of 122 individuals with ASPD that selected from prisoners (73.0), outpatients (18.0), and inpatients (9.0). Th ey were recruited from Tehran Prisoners, and Clinical Psychology and Psychiatry Clinics of Razi and Taleghani Hospitals, Tehran, Iran, since 2013-2014. Th e Sample was selected based on judgmental sampling. Th e structured clinical interview for DSM-IV axis II disorders-Personality Questionnaire, NEO-Personality Inventory-Revised, and DSM-5 personality trait rating form were used to diagnosis and assessment of personality disorder. Pearson correlation has been used for data analysis. All statistical analyses were performed using the SPSS 16 software. Results: Th e results indicate that neuroticism (N) has positive signifi cant relationship with hostility (r = 0.33, P < 0.01), manipulativeness (r = 0.25, P < 0.01), deceitfulness (r =.23, P < 0.01), impulsivity (r = 0.20, P < 0.05), and negative relation with risk taking (r = �0.23, P < 0.01). Also, there was signifi cant relationship between extraversion (E) with manipulativeness (r = 0.28, P < 0.01) and deceitfulness (r = 0.32, P < 0.01). Agreeableness and conscientiousness have negative signifi cant relation with DSM-5 traits. In addition, results showed that there is positive signifi cant relationship between FFM and DSM-5 personality traits with DSM-fourth edition-text revision (DSM-IV-TR) ASPD symptoms (P < 0.01). Conclusion: Except manipulativeness, deceitfulness, and callousness, there is positively signifi cant relationship between DSM-5 ASPD traits and DSM-IV-TR ASPD symptoms. Th e present study helps to understand the adequacy of dimensional approach to evaluation of ASPD pathology, specifi cally on Iranian sample. © 2015 Journal of Research in Medical Sciences

    Magnetic interference pattern in planar SNS Josephson junctions

    Full text link
    We study the Josephson current through a ballistic normal metal layer of thickness DD on which two superconducting electrodes are deposited within a distance LL of each other. In the presence of an ({\it in-layer}) magnetic field we find that the oscillations of the critical current Ic(Φ)I_c(\Phi) with the magnetic flux Φ\Phi are significantly different from an ordinary magnetic interference pattern. Depending on the ratio L/DL/D and temperature, Ic(Φ)I_c(\Phi)-oscillations can have a period smaller than flux quantum Φ0\Phi_0, nonzero minima and damping rate much smaller than 1/Φ1/\Phi. Similar anomalous magnetic interference pattern was recently observed experimentally.Comment: 6 pages, 4 figures, Accepted by Phys. Rev.

    Nonsinusoidal current-phase relations and the 0π0-\pi transition in diffusive ferromagnetic Josephson junctions

    Full text link
    We study the effect of the interfacial transparency on the Josephson current in a diffusive ferromagnetic contact between two superconductors. In contrast to the cases of the fully transparent and the low-transparency interfaces, the current-phase relation is shown to be nonsinusoidal for a finite transparency. It is demonstrated that even for the nearly fully transparent interfaces the small corrections due to weak interfacial disorders contribute a small second-harmonic component in the current-phase relation. For a certain thicknesses of the ferromagnetic contact and the exchange field this can lead to a tiny minimum supercurrent at the crossover between 0 and π\pi states of the junction. Our theory has a satisfactory agreement with the recent experiments in which a finite supercurrent was observed at the transition temperature. We further explain the possibility for observation of a large residual supercurrent if the interfaces have an intermediate transparency.Comment: 7 pages, 4 figure

    Improving depth resolution of ultrasonic phased array imaging to inspect aerospace composite structures

    Get PDF
    In this paper, we present challenges and achievements in development and use of a compact ultrasonic Phased Array (PA) module with signal processing and imaging technology for autonomous non-destructive evaluation of composite aerospace structures. We analyse two different sets of ultrasonic scan data, acquired from 5 MHz and 10 MHz PA transducers. Although higher frequency transducers promise higher axial (depth) resolution in PA imaging, we face several signal processing challenges to detect defects in composite specimens at 10 MHz. One of the challenges is the presence of multiple echoes at the boundary of the composite layers called structural noise. Here, we propose a wavelet transform-based algorithm that is able to detect and characterize defects (depth, size, and shape in 3D plots). This algorithm uses a smart thresholding technique based on the extracted statistical mean and standard deviation of the structural noise. Finally, we use the proposed algorithm to detect and characterize defects in a standard calibration specimen and validate the results by comparing to the designed depth information

    A discriminant analysis model of psychosocial predictors of problematic internet use and cannabis use disorder in university students

    Get PDF
    Researchers have found similarities and differences between behavioral and drug addictions. The present study was designed to explore which of a series of psychosocial predictors of addictive behaviors could differentiate problematic Internet use (PIU) and Cannabis Use Disorder (CUD) in a sample of University students. A total of 144 participants (76 males, mean age = 23.03 years ± 2.83) were separated into three groups: those presenting with PIU (18 females, Mean age = 22.27 years), those presenting with CUD (22 female, Mean age = 22.73 years), and a control group (28 female, Mean age = 24.04 years). Participants completed the Internet Abusive Use Questionnaire (IAUQ), the Severity of Dependence Scale (SDS), the Multidimensional Scale of Perceived Social Support (MSPSS), the Barratt Impulsiveness Scale-11 (BIS-11), the Multidimensional Distress Tolerance Scale (MDTS), the Emotion Regulation Questionnaire (ERQ), the Metacognitions Questionnaire-30 (MCQ-30), and the Repetitive Thinking Questionnaire-10 (RTQ-10). The classification analysis results showed that 68.8% of the control group, 70.8% of the PIU group, and 81.3% of the CUD group were correctly classified in their respective groups. In addition, the results of the discriminant function analysis showed that there was a significant difference between members of the PIU and CUD groups in the degree of family support (0.45), significant other (0.33), tolerance of physical discomfort (0.30), reappraisal (0.42), and cognitive confidence (0.35). The findings provide evidence that specific psychosocial predictors can discriminate PIU from CUD. [Abstract copyright: © 2021 The Author(s).

    Single-cell delineation of lineage and genetic identity in the mouse brain

    Get PDF
    During neurogenesis, mitotic progenitor cells lining the ventricles ofthe embryonic mouse brain undergo their final rounds of cell division, giving rise to a wide spectrum of postmitotic neurons and glia(1,2). The link between developmental lineage and cell-type diversity remains an open question. Here we used massively parallel tagging of progenitors to track clonal relationships and transcriptomic signatures during mouse forebrain development. We quantified clonal divergence and convergence across all major cell classes postnatally, and found diverse types of GABAergic neuron that share a common lineage. Divergence of GABAergic clones occurred during embryogenesis upon cell-cycle exit, suggesting that differentiation into subtypes is initiated as a lineage-dependent process at the progenitor cell level
    corecore