438 research outputs found

    Portal steel trusses vs. portal steel frames for long-span industrial buildings

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    © 2018 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin Portal frames and portal truss structures are two of the most cost-effective and sustainable structural forms for the design and construction of long-span industrial buildings. Although the use of both structure types as steel-clad structures is widely accepted, due to frame complexity and variation of frame types for use in single-storey buildings with spans > 30 m, literature providing a comprehensive investigation of the concepts of portal trusses and portal frames is scarce. This study compares the behaviour of a portal truss configuration with pitched portal frames for use in industrial buildings with spans > 30 m, focusing on weight, costs and construction time. Furthermore, this study entails a numerical investigation that utilizes the SAP2000 computer program to model and structurally optimize the member properties for both portal frame and portal truss configurations. Based on the results obtained from the investigation, it has become apparent that, due to the smaller sections used, the portal truss configurations are lighter and cheaper to fabricate and construct in comparison to the pitched portal frames, which, however, require a shorter construction time

    Hard Balancing Rusia dan Turki dalam Konflik Suriah 2012-2015

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    The Syrian conflict that has been raging since 2011, has involved external actors including Russia and Turkey in a rivalry model of “hard balancing.” Those two countries support different contested parties in the Syrian conflict. This article is aimed to describe the background, forms, and the impact of the hard-balancing rivalry between Russian and Turkey in the conflict. Russia\u27s involvement in the conflict is to back up Bashar al Assad\u27s regime politically and militarily in order to protect its military and economic interests in the region, while Turki provides supports to the rebels. The rivalry between the the two countries has made the Syrian conclict more complicated and long-drawn

    Theoretical Study of the [4+2] Cycloaddition Reaction of Trifluoroethylene with Five-membered Chalcogens Heterocyclic Compounds

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    [4+2] cycloaddition reaction has enormous significant in organic chemistry synthesis reactions and yet remains unexplored for the synthesis of fluorine-containing compounds. A density functional theory study of the stereo- and regioselectivity of the [4+2] cycloaddition reaction of trifluoroethylene with furan, thiophene, and selenophene was carried out in the gas phase. The B3LYP functional is used throughout in combination with 6-31G(d) basis set. The analysis of stationary points and the energetic parameters indicates that the reaction mechanism is concerted and confirms that the exo-adducts are thermodynamically and kinetically more favored than endo-adducts. The calculated branching ratio indicates that the exo-adducts have the higher percent yield than endoadducts and the yield of endo-adducts is increased only slightly on proceeding from furan, through thiophene, and onto selenophene. The analysis of the frontier molecular highest occupied molecular orbital (MO) and lowest unoccupied MO orbitals indicates that the exo-adducts are more stable due to their higher energy gab. The reaction energies were compared to the MP2/6-31G(d) and CCSD(T)/6-31G(d) calculations

    Multimetal organic frameworks as drug carriers: Aceclofenac as a drug candidate

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    Background: Multimetal organic frameworks (M-MOFs) were synthesized by including a second metal ion with the main base metal in the synthesis process to enhance their applications for drug delivery. Aceclofenac (ACF), a nonsteroidal anti-inflammatory analgesic drug of low aqueous solubility, was selected as a candidate for the drug delivery system Purpose: This study aimed to evaluate the loading capacity (LC) and entrapment efficiency (EE) percentages of multi-Material of Institute Lavoisier (MIL)-100(Fe) (M-MIL-100(Fe)) for ACF. Materials and methods: Hydrothermal synthesis procedure was used to prepare multi-MIL-100(Fe) samples (Zn I-MIL-100(Fe), Zn II-MIL-100(Fe), Ca I-MIL-100(Fe), Ca II-MIL-100-(Fe), Mg I-MIL-100(Fe), Mg II-MIL-100(Fe), Mn I-MIL-100(Fe), and Mn II-MIL-100(Fe)). The characterization of M-MIL-100(Fe) samples was evaluated by X-ray powder diffraction (XRD), Fourier transform infrared spectra, scanning electron microscope (SEM), TGA, and N2 adsorption isotherms. The LC of M-MIL-100(Fe) and EE of ACF were determined. Nuclear magnetic resonance (NMR) and zeta-potential analyses were employed to confirm qualitatively the drug loading within M-MIL-100(Fe). Results: The ACF LC of MIL-100(Fe) was 27%, whereas the LC of M-MIL-100(Fe) was significantly increased and ranged from 37% in Ca I-MIL-100(Fe) to about 57% and 59% in Mn II-MIL-100(Fe) and Zn II-MIL-100(Fe), respectively. The ACF@M-MOFs release profiles showed slow release rates in phosphate buffer solutions at pH 6.8 and 7.4 as compared to the ACF@MIL-100(Fe). Conclusion: Therefore, M-MOFs showed a significant potential as a carrier for drug delivery systems

    Farm-Level Feed Demand in Turkey

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    Using farm-level survey data from Turkey, the authors provide estimates of the price responsiveness of feed demand beef, dairy, and sheep producers. In addition, the authors assess the impact of feed quality on animal yields in the Turkish dairy cattle sector

    Investigation the Coating of Hydroxyapatite on Titanium Substrate by Pulse Laser Deposition

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    بحثت هذه الدراسة وأعدت طلاء مركب للمزروعات الجراحية باستخدام المواد السيراميكيه النشطه بايولوجيا (bioactive) مثل الهيدروكسيابتايت كطلاءات للمزروعات المعدنيه التي تشجع النمو الطبيعي للعظام عند نقاط التماس بينها وبين العظم الحي. ان الهيدروكسيابتايت (Ca10(PO4)6(OH)2)) او فوسفات الكالسيوم يستخدم كطلاء للمعادن بسبب توافقيته الحياتيه الممتازه كما انه ذو هيكل مشابه للانسجه الصلبه في جسم الانسان. إن تطبيق الطلاء HA على ركائز التيتانيوم أنتجت باستخدام تقنية الترسيب بالليزر النبضي (Pulsed Laser Deposition). في هذا البحث استخدم (HA) كهدف ((Target تم كبسه عند ضغط (150MPa) مع حجم حبيبي مقداره 2.745 µm)) واستخدامه في عملية الطلاء بواسطة تقنية(PLD). أجريت عدة اختبارات لتوصيف طبقة الطلاء مثل XRD وSEM وAFM وEDX لتحديد كمية كلا من الكالسيوم (Ca) والفسفور (P) في طبقة الطلاء. وبعدها تم اختبار الصلاده وخشونة السطح لطبقه الطلاء HA)). تم اجراء اختبار التآكل باستخدام طريقة استكمال منحني تافل في محلول Hank's solution لكل النماذج المطليه وغير المطليه، حيث حصلنا في هذا الاختبار على تحسن كبير في مقاومة التآكل للعينات المطليه عند عدد نبضات 4000 نبضة بمقدار 99.88%.This study investigated and prepared a coating for surgical implants by using hydroxyapatite (HA) empowers characteristic bone that developed at a medium for prosthetic the parts of human body. HA is the generally manufactured from both Calcium (Ca) and Phosphate (P) to produce (Ca10(PO4)6(OH)2) that used as a base material for covering mineral embeds because of its incredible biocompatibility and comparable the synthesis and structure to sclerous tissues of the human body. HA, coatings on titanium substrates have been produced by Pulses laser deposition (PLD) techniques. HA used in this search pressed at pressure (150MPa) with particle size (2.745 µm) and used as a target in coating by (PLD) techniques. Surface characterization studies of the coatings such as XRD, SEM, AFM and EDX to detect the amount of (Ca) and (P) in coating layer were carried out. Then test the micro-hardness, surface roughness for HA coating .Corrosion behavior for uncoated and coated samples with various number of pulses in Hank’s solution by using OCP and the potentially static polarization test were achieved also, , in this test we obtained a greatly improved in corrosion resistance of the samples B1 after coating by 99.88%

    The effect of wastewater disposal on the water quality and phytoplankton in Erbil wastewater channel.

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    In this study, phytoplankton density, chlorophyll-a, and selected physico- chemical parameters were investigated in Erbil wastewater channel. The surveys were carried out monthly from May 2003 to April 2004. Samplings were established on three sites from headwaters to the mouth. The results showed that pH was in alkaline side of neutrality, with significant differences (

    Urethrocutaneous fistula following hypospadias repair: regional anesthesia and other factors

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115999/1/pan12719.pd

    PURIFICATION, CHARACTERIZATION AND EVALUATION OF BIOLOGICAL ACTIVITY OF MANNOPROTEIN PRODUCED FROM SACCHAROMYCES CEREVISIAE BY

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    The current study was aimed to evaluate the biological activity of mannoprotein produce from local isolate S. cerevisiae BY. The results of purified mannoprotein using gel filtration chromatography revealed higher ratio of protein to mannose reached to 87.1%. FTIR indicated the presence of C-H and O-H bands could be due to the protein and carbohydrate components, respectively.C=N band due to acylated amino sugars frequently found in glycoproteins, HPLC indicated the presence of mannoprotein to 12 kinds of amino acid.Antibacterial, anti-adhesion and anti-biofilm activities of mannoprotein were evaluated against some pathogenic bacteria. Mannoprotein showed slightly inhibition zones ranged (10to14mm) and(9to 13mm) against P.aeruginosa and S.aureus respectively at concentration of mannoprotein from 50 to 200 mg/ml.The results showed higher anti-adhesive property of mannoprorein against P.aeruginosa (51.1%) and slightly antiadhesion againstS. aureus 19% at 200 mg / ml of mannoprotein. Results of the anti-biofilm activity rises as the concentration of mannoprotein increases and reached to 51.8% against P. aeruginosa while slightly anti biofilm (19.7%) against S. aureus, at concentration of 200 mg/ml. The synergistic effect of mannoprotein with some antibiotics was studied.The combination of mannoprotein and antibiotics (Tetracycline, Gentamycin, Ampicillin and Ciprofloxacin)(1:1) at concentration 1mg/ml were studied. Results showed enhancement 26, 29, 33 and 36% of inhibition zone against P. aeruginosa while, enhancement was 20, 33, 40, and 14 % for S. aureus, respectively. The results demonstrated that mannoprotein possess antimicrobial activity in nature. Hence if co-administrated with another inhibitory agent, the mixture reduces the survival of pathogens
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