In this study, the response of ten composite post-tensioned concrete beams topped by a reinforced concrete deck with adequate reinforcing shear connectors is investigated. Depending on the concrete compressive strength of the deck slab (20, 30, and 40 MPa), beams are grouped into three categories. Seven of these beams are exposed to a fire attack of 700 and 800 °C temperature simultaneously with or without the presence of a uniformly distributed sustained static loading. After cooling back to ambient temperature, these composite beams are loaded up to failure, using a force control module, by monotonic static loading in a four-point-bending setup with two symmetrical concentrated loads applied in the middle third of the effective span. The objectives of this study include investigating the behavior of the composite prestressed concrete beams under and after the exposure to a direct fire flame, as well as finding their residual load-carrying capacity. Tests demonstrate significant deteriorations caused by exposure to high temperatures associated with the increase of the member’s camber. The increase of the midspan camber after heating exposure reached approximately 200%. On the other hand, the 1-h steady-state exposure of test specimens to temperatures of 700 and 800 °C led to reduce the load-carrying capacity of the heat-deteriorated beams up to 45% and 54%, respectively.
Introduction:Serratia marcescens is a gram-negative pathogen of many species. Its pathogenicity and survival are linked to its capacity to build biofilms as well as its strong inherent resistance to antimicrobials and cleaning agents. Objectives: To analyse the impact of glyceryl trinitrate (GTN) on the gene expression of QS-related genes (rssB, rsmA,and pigP) of S. marcescens. Methodology: The broth microdilution technique estimated the bactericidal effectiveness of glyceryl trinitrate. The presence of rssB, rsmA,and pigP in S. marcescens isolates was detected using PCR. qRT-PCR was used to assess the effect of GTN on rssB, rsmA,and pigPgene expression. Results: The results demonstrated that GTN has no effect on S. marcesce
... Show MoreEsterification reaction is most important reaction in biodiesel production. In this study, oleic acid was used as a suggested feedstock to study and simulate production of biodiesel. Batch esterification of oleic acid was carried out at operating conditions; temperature from 40 to 70 °C, ethanol to oleic acid molar ratio from 1/1 to 6/1, H2SO4 as the catalyst 1 and 5% wt of oleic acid, reaction time up to 180 min. The optimum conditions for the esterification reaction were molar ratio of ethanol/oleic acid 6/1, 5%wt H2SO4 relative to oleic acid, 70 °C, 90 min and conversion of oleic 0.92. The activation energy for the suggested model was 26625 J/mole for forward reaction and 42189 J/mole for equilibrium constant. The obtained results s
... Show MoreForty one isolates of genus Proteus were collected from 140 clinical specimens such as urine, stool, wound, burn, and ear swabs from patients of both sex. These isolates were identified to three Proteus spp. P. mirabilis, P. vulgaris and P. penneri .The ability of these bacteria to produce L-asparaginase II by using semi quantitative and quantitative methods was determined. P. vulgaris Pv.U.92 was distinguished for high level of L-asparaginase II production with specific activity 1.97 U/mg. Optimum conditions for enzyme production were determined; D medium with 0.3% of L-asparagine at pH 7.5 with temperature degree 35°C for incubation. Ultrasonication was used to destroy the P. vulgaris Pv.U.92 cells then ASNase II was extracted and pu
... Show MoreBackground: Hypothyroidism is the most prevalent thyroid disorders worldwide. Hypothyroidism manifestations are wide spectrum, affecting various systems in human body including the nervous system. Hypothyroidism can cause neuropsychiatric symptoms such as anxiety, depression and diminishing in attention, memory and executive function. Aim: to investigate the level of anxiety and depression in patients with hypothyroidism receiving levothyroxine treatment. Method: a cross-sectional study was conducted at Baghdad Center for Nuclear Medicine and Radiation Therapy from March to June 2022. The study population included patients of both genders, aged 18-65 years, diagnosed with hypothyroidism, were receiving levothyroxine treatment and
... Show MoreOur goal in this research, some new nucleoside analogues was synthesized. Starting from ?-D glucose which was converted to per acetylated ?-D gluco pyronoside then converted to active from(1-Bromo Sugar (2) as a sugar moiety.The base moiety 2-substituted benzimidazole was prepared from condensation of phenylene diamine with different aromatic aldehydes, which were subjected to amino alkylation via Mannich reaction forming new nucleobase derivatives. Condensation of nucleobase with bromo sugar through nucleophilic substitution of anomeric carbon with nitrogen forming new protected nucleoside analogues then hydrolyzed with sodium methoxide in methanol to obtain our target, the free nucleoside analogues. All prepared compound were identified b
... Show MoreAbstract
This research aims to study and improve the passivating specifications of rubber resistant to vibration. In this paper, seven different rubber recipes were prepared based on mixtures of natural rubber(NR) as an essential part in addition to the synthetic rubber (IIR, BRcis, SBR, CR)with different rates. Mechanical tests such as tensile strength, hardness, friction, resistance to compression, fatigue and creep testing in addition to the rheological test were performed. Furthermore, scanning electron microscopy (SEM)test was used to examine the structure morphology of rubber. After studying and analyzing the results, we found that, recipe containing (BRcis) of 40% from th
... Show MoreAn experiment during the two seasons 2019, 2020. The experiment conducted according to Split Plot Design by two factors; the first was addition Nano NPK with five levels (control, addition 7.5 g.plant-1, addition 15 g.plant-1, spray 1 g.L-1, spray 2 g.L-1). The second factor was four levels of Mineral NPK which were (control, 50 g.plant-1, 100 g.plant-1, 50 g.plant-1+1.5 g.L-1) respectively. N3 (spray 1 g.L-1 ) increased plant height, stem diameter first season, branch number se