204 research outputs found

    Synthesis of Nano-Crystalline TiC Powder from Active Impure Ti Chips via Self Propagating High-Temperature Synthesis and the Effect of Al on the Synthesis Temperature

    Get PDF
    In this research, the possibility of production of TiC powder from inexpensive raw materials via simple methods has been investigated. Impure Ti chips, carbon black and Al powder were activated by a highenergy ball mill. Then they were synthesized by the method of self propagating high-temperature synthesis (SHS) at various temperatures. XRD study indicated that TiC within 1000 °C to 1300 °C temperature range has been synthesized where the temperature in a sample containing Al was less than 1000 °C. From the broadening of the diffraction lines in the XRD patterns, it was concluded that the TiC crystallites were nanosized and the lattice parameter had deviated slightly from the standard size. The existence of Al increased the lattice parameter of TiC and the strain in the process

    Modeling of environmental aspects related to reverse osmosis desalination supply chain

    Get PDF
    open access journalBackground: This study aimed to model optimization of strategic environmental management decisions in the operation of reverse osmosis desalination, emphasizing the costs required for the environmental protection during the production of freshwater using reverse osmosis technology. Methods: This analytical research was conducted in five cities of Hormozgan province in Iran for 18 months from February 2018 to September 2019. The research includes eight phases of defining the research problem, data collection, preliminary data analysis and decision criteria, mathematical modeling, model validation, information preparation, analysis and finally discussion, conclusions and suggestions. The main environmental issues were the carbon dioxide (CO2) release rate due to power demand and rejected brine water (RBW) were entered the mathematical model. Results: The desalination plants of Abu Musa, Bandar Abbas, Qeshm, Sirik, and Hormoz with water production flow rate of 2100, 89 000, 5300, 3300 and 1500 m3/d can generate 2360.82, 100053.80, 5958.260, 3709.86 and 1686.30 tons/year of CO2 emissions respectively. This output requires 1.35, 57.47,3.42, 2.13 and 0.97 million USD for controlling the process, respectively. For reduction of the negative effect of RBW 0.75, 22.79, 1.78, 1.15 and 0.55 million USD respectively, is needed. Conclusion: Recommendations for environmental impacts protection of RBW, for desalination capacity up to 50 000 m3/d, are; (a) for desalination capacity up to 50 000 m3/d; dilution the RBW using raw water before entering into the sea, (b) for capacity of 50 000-100 000 m3/d; dispersing RBW in sea using diffuser, and (c) for capacity more than 100 000 m3/d; hybrid water desalination plants and power plant. Application of power plant cooling water to dilute RBW may reduce cost

    The Effect of an Enamel Matrix Derivative (Emdogain) Combined with Bone Ceramic on Bone Formation in Mandibular Defects: A Histomorphometric and Immunohistochemical Study in the Canine

    Get PDF
    Background. The purpose of this study was to evaluate the combination of an enamel matrix derivative (EMD) and an osteoconductive bone ceramic (BC) in improving bone regeneration. Materials and Methods. Four cylindrical cavities (6 × 6 mm) were prepared bilaterally in the mandible in three dogs. The defects were randomly assigned to four different treatments—filled with EMD/BC and covered with a nonresorbable membrane, filled with EMD/BC without membrane, membrane coverage only, or control (left untreated)—and healed for 2, 4, or 6 weeks. Harvested specimens were prepared for histologic, histomorphometric, and immunohistochemical analyses. Results. Sites treated with EMD/BC with or without membrane showed more total bone formation and lamellar bone formation than membrane-only and control defects. There were no statistically significant differences in total bone formation between EMD/BC with or without membrane. Conclusion. EMD with BC might improve bone formation in osseous defects more than membrane coverage alone; the use of a membrane had no significant additive effect on total bone formation

    Involvement of the nucleus accumbensshell presynaptic NMDA receptors on anxiolytic-like behaviors induced by NMDA in adult male Wistar rat

    Get PDF
         Glutamatergic system stimulationthe nucleus accumbens shell, may affect anxiety-related behaviors, aversive learning and memory. Glutamate receptors are differentially distributed in pre- and postsynaptic sites contributing to neuronal communications.The present study aimed to examine the possible involvement of the NAc shell presynaptic NMDA receptors on NMDA induced responses, using the elevated-plus maze (EPM) task in maleWistar rats. Bilateral guide cannulae were implanted to allow microinjection of glutamatergic agonist (NMDA) or ca+2 channel blocker (SKF96365 hydrochloride) agents. Pretest intra-NAc shell infusion of NMDA induced anxiolytic-like behaviors and impaired the EPM-associated memory upon test and retest, respectively. In addition our findings showed that, the intra-NAc shell infusion of Ca+2 channel blocker at applied doses, does not alter the anxiety-like response and aversive memory upon test and retest, respectively. Furthermore, infusing the subthreshold dose SKF prior to the injection of effective doses of NMDA, reduced the anxiolytic-like response and improved the aversive memory impairment which had already been induced by intra-NAc shell NMDA injection. Our study showed that,inhibition of the neurotransmitter exocytosis from pre-synaptic neuron via Ca+2 channel blockade bySKF96365 decreases affected induced by NMDA in the NAc shell region, indicating the involvement of the pre-synaptic NMDA receptors in NMDA induced responses.Therefore, NMDA's ability to increase anxiolytic-like behaviors and the aversive memory impairment may be the result of an action on pre-synaptic glutamatergic receptors which in turn decrease the glutamate effect at synaptic terminal level

    The Comparative Semantics of the Term Irteqab (Revelation) in Sunni and Shi’ite Exegesis

    Get PDF
    Translators of the words of Wahy (revelation) have considered some vocabularies as synonymous with each other in the translation of the Qur’an. Moreover, sometimes they have applied one single meaning as equivalent for different Arabic words in the Qur’an while paying attention to the accurate meaning of the words is a way to untangle the mystery of some Quranic verses and traditions. Using pictorial translation can provide a more meaningful translation than what Sunni and Shi’ite translators have already stated in their books. The term “Irteqab” in Sunni and Shi’ite exegesis is considered as synonymous with “waiting” so its semantic delicacies are ignored. Comparing Sunni and Shi’ite exegetic theories, it is attempted in this study to delve deep into the ignored points in translation and to analyze the semantics of the term using pictorial interpretative method relying on the Qur’an and the style of the verses in the story of Naqeh Saleh (the miracle camel of Prophet Saleh) in Surah al-Qamar. In addition to maintaining conceptual structure and consistency with the concepts provided by verbal dictionaries, the pictorial interpretative method in this study represents more accurate, tangible, and practical meaning along with the Quranic divine programs for the intended words. Among Sunni and Shi’ite early commentators, Zeyd ibn Ali, Hasan ibn Abi al-Hasan, Abu Sa’iid Khudri, and most importantly Imam Ali (PBUH) have discussed the subject of “Irteqab in Surah Ad-Dukhan” more precisely

    Induced Myopia Secondary to Blunt Trauma

    Get PDF
    A 28-year-old young man presented with sudden and severe visual loss in the left eye, starting three days ago following blunt head trauma from a closed fist. Vision was not improved to better than 0.4 in the left eye. Slit lamp examinations revealed asymmetric anterior chamber depth (ACD) with shallow ACD in the left eye. The key learning in this report is the use of anterior segment optical coherence tomography (AS-OCT) to better document the anterior segment changes following the blunt trauma. AS-OCT was used to visualize the forward displacement of the iris-crystalline lens diaphragm secondary to ciliary body anterior rotation and ciliochoroidal effusion. There was a temporary myopic shift about 7.00D which resolved after 15 days

    Comparison of three primer pairs included: novel primers IS711, universal primers B4 - B5 and 16SrRNA in the diagnosis of human brucellosis in suspected patients in Iran

    Get PDF
    The genus Brucella is a worldwide distributed intracellular bacteria, which infects animals and human. Currently, this zoonosis has been diagnosed by microbiological and serological laboratory tests. Different PCR protocols with various primer pairs and different target genes have been published for the detection of Brucella, but only a few of these primers have been used in human samples. This study aimed to evaluate and compare the sensitivity and specificity of three primer pairs in the PCR technique, each of which separately amplifies three different regions in the Brucella genome, to determine which are more comfortable for the detecting of Brucella DNA in human clinical samples. 49 clinical serum samples were isolated from suspected patients in different cities in Iran from October 2017 to July 2018. The suspected patients with brucellosis-compatible symptoms were checked. These primers amplified 3 distinctive fragments in BCSP 31 gene (B4/B5), Designed IS711 primers, and a sequence of 16SrRNA of Brucella melitensis. The results showed that the B4/B5 primer pair had the highest sensitivity and specificity for the detection of both positive and negative samples (100%). The designed IS711 primer pair detected 94% of samples, whereas the 16SrRNA primer pair was the least sensitivity, being able to detect only 30.64% of samples. The specificity of 3 techniques was 100%. The B4/B5 primers were able to detect the smallest number of bacteria 0.05 CFU/reaction whereas IS711 was able to detect 2 CFU/reaction and 16SrRNA was able to detect 2×105 CFU/reaction. &nbsp

    Farm Science Reporter Vol. 6 No. 1

    Get PDF
    <p>(a) <i>Ev</i> as function of diameter ratio for different length ratios;(b) <i>Ev</i> as function of length ratio for different diameter ratios.</p

    Retro MTA and tricalcium phosphate/retro MTA for guided tissue regeneration of periodontal dehiscence defects in a dog model: a pilot study

    Full text link
    Objectives: Retro MTA is a fast setting Calcium silicate cement used in endodontic regeneration procedures in recent years. Beta-tricalcium phosphate (β-TCP) is another common biomaterial used for bone augmentation procedures. The present pilot study was undertaken to evaluate and compare the efficacy of Retro MTA and a mixture of Retro MTA / β-TCP for periodontal tissue regeneration. Materials and methods: In 4 beagle dogs, periodontal dehiscence type defects were created. In each side, one dehiscence defect was left empty as a control site and three treatment modalities were randomly applied for the others: Retro MTA covered with a collagen membrane, Retro MTA + β-TCP covered with a membrane and covering the defect with a membrane without any bone augmentation. After 8 weeks Animals were sacrificed and Histomorphometric and histologic analysis were conducted. Results: Histologic analysis showed more cementum formation for both Retro MTA+ β-TCP (3.74 ± 0.34 mm) and Retro MTA group (3.24 ± 0.56 mm) compared to control group 1 (1. 15 ± 0.45 mm) and control group 2 (0.78 ± 0.65 mm). Formation of newly formed bone and cementum in the experimental groups were significantly higher as compared to the control groups (P < 0.0001). Conclusions: Retro MTA or Retro MTA+ β-TCP covered with a collagen membrane resulted in regeneration of periodontal tissues. However, Retro MTA+ β-TCP showed tendency towards better results than the use of Retro MTA alone. KEYWORDS: Bone regeneration; Calcium silicate cement; Guided tissue regeneration; MT
    corecore