1,982 research outputs found

    Finite Element Modelling of Strengthened Simple Beams using FRP Techniques: A parametric Study

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    The main objective of this paper is to study analytically the strengthening of a simplereinforced concrete beams due to excessive uniform loads in flexure, shear and acombination of flexure and shear, using externally bonded FRP sheets technique. Acommercial finite element computer program ANSYS has been used to perform a structurallinear and non-linear analysis for several models using several schemes of FRP sheets. Aparametric study has been performed for a lot of strengthened beams. FE models studies amain parameter of different schemes of FRP sheets in flexure, shear and combinationflexure/shear. Comparing the results with a control beam model – simple reinforcedconcrete beam without strengthening – it is obvious that all strengthened beams have agreater ultimate capacity than the control beam and noticeable enhancement in memberductility. The increasing level differs as a result of the strengthening scheme. Thestrengthened beam in both flexure and shear gives a higher ultimate load capacity, delay thefailure and prevent debonding failure up to a level at which debonding occurs in bothlongitudinal and wrapped jackets CFRP sheets

    INVESTIGATION OF THE EFFECT OF TEMPERATURE AND TIME OF CASE HARDENING ON THE MECHANICAL PROPERTIES AND MICROSTRUCTURE OF LOW CARBON STEEL (AISI 1020)

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    The main objective of this paper is experimental study of pack carburizing of carbon steels (AISI 1020) by using two parameters (holding time and carburizing temperature). This study was conducted by using electrical furnace. This process is carried out at temperatures of 950°C for durations time 90 minutes. From the experiment, the surface hardness and thickness of carbon layer was different according to the parameters used. The quenching medium that uses in this experiment is water, oil, sea water and air. For carburizing temperature at 950°C, the highest of surface hardness value for air is 128 HV that carburized for 90 minutes, the highest of surface hardness value for water is 224 HV that carburized for 90 minutes. For carburizing temperature of 950°C, the highest of surface hardness value for sea water is 166.9 HV that carburized for 90 minutes and for carburizing temperature at 950°C which is the highest of surface hardness value for oil is 126 HV. The thickness of carbon layer was between 40μm to 120μm. The result indicates the carburizing process accelerates the diffusion of carbon atoms into the surface, thus increasing the thickness of carburized layer as well as the surface hardness

    In vitro Anti-Leishmania Activity and Safety of Newly Synthesized Thiazolo Pyrimidine Derivatives Augmented with Interleukine-12 (IL-12) in BALB/c Mice Experimentally- Infected with Cutaneous Leishmaniasis

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    Purpose: To synthesize a series of novel thiazolo pyrimidine derivatives and evaluate them in vitro and in vivo for their safety and anti-leishmanial activity using BALB/c mice.Methods: Substituted pyrazolopyrimidine and pyrazolopyrazole were synthesized by reacting amino group of 2-amino-4-cyano-pyrazol]naphthalino[1,2-d]thiazole with a variety of formamide or hydrazine hydrate. The synthesized compounds were characterized by nuclear magnetic resonance spectroscopy (1H-NMR) and mass spectroscopy (MS). The purity of the compounds was determined by elemental analysis. Safety and anti-leishmanial activity of the compounds were determined in vitro by i) viability assessment of leishmania-infected macrophages, relative abundance of IL-12p40 mRNA gene expression and levels of IL10 /IL-12 determination in supernatants of cultured macrophages treated with 2.5 and 10 μM of the compounds, using microscope cell counting, reverse transcriptase polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA), respectively. ii) cytotoxicity of the compounds evaluated by determination the safety index as IC50 of the compound in macrophages/IC50 of the compound in amastigotes. iii) bioassay at 16 weeks post-infection of mice treated with the reference drug, the tested compound alone and both the compound with IL-12. Disease progression and footpad thickness were evaluated regularly during treatment.Results: Compound 4 emerged as the most active anti-protozoal compound of the series against Leishmania viability (activity 60 %) compared with the reference drug (activity 65 %). When it was combined with IL-12, the activity reached 90 %.Conclusion: Compound 4 can serve as a lead molecule for further development to a clinically useful novel class of agents.Keywords: Thiazolopyrimidine, Synthesis, Leishmaniasis, Mice, Immunotherap

    Data Mining for Enhanced Security: A Transformative Framework for Smart Grid Protection

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    Smart grids fall at the intersection of conventional energy systems and modern informatics in the present digitalized energy environment. The growing number of linked devices and sensors in these networks leads to the generation of complex structures and vast quantities of data, presenting benefits and challenges. Safeguarding these complex structures against malicious intrusions and illegal activities is an important problem. The paper's main objective is to enhance smart grid security by utilizing the data mining and Artificial Intelligence (AI) approaches. As huge amounts of data are collected from the smart grids based on tiny and smart internet of things (IoT) devices, this data poses challenges as well as provides opportunities. The challenges come from analyzing this huge data, especially in real-time. At the same time, it provides opportunities to enhance the smart grid services and protection. Therefore, to overcome these challenges, this paper proposes a feedforward deep learning approach for data mining to secure the smart grid from different anomalies and allow the system to adapt to any risk it might face. Deep learning will allow the system to adjust dynamically to emerging risks. The proposed system has been examined using Power System Attack Datasets sourced from the Mississippi State University and Oak Ridge National Laboratory. The results show a detection accuracy of 91% just using 50% of the dataset features. Different percentages of the features are examined as well. However, we concluded that 50% of the features are enough for identifying the smart grid risks based on the given dataset

    Characterization of a New Biotype Moringa of Saudi Arabia Using Rapd and Issr Markers

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    Moringa peregrina and M. oleifera are the only Moringa species found in Saudi Arabia. Both species are drought resistant and have very high nutritional and medicinal properties. Detection of genetic diversity is of great value for the improvement of nutritional and medicinal value of these plants. The aim of the present study was to characterize a new biotype Moringa observed in Al Bahah Region, Saudi Arabia. We used 11 RAPD and 15 ISSR primers to characterize and compare the new biotype with M. peregrina and M. oleifera. Level of polymorphism generated by each marker was calculated. We also calculate Nei and Li\u27s coefficient to measure the genetic distance between the studied species. Level of polymorphism generated by RAPD and ISSR was 46% and 57%, respectively. RAPD and ISSR primers revealed that the new biotype shared 55 amplicons (45.08%) with both M. peregrina and M. oleifera, 28 amplicons with M. peregrina (22.95%), 21 amplicons (17.21%) with M. oleifera, and displayed 18 unshared amplicons (14.75%). Based on RAPD data, genetic distance between M. oleifera and M. peregrina was 0.32, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.21 and 0.29, respectively. For ISSR data, genetic distance between M. oleifera and M. peregrina was 0.5, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.36 and 0.34, respectively. Based on these results we suggested that the new biotype is a hybrid crossbred between M. peregrina and M. oleifera

    New Azacycles by One-Pot Three-Component Hantzsch-Like Synthesis of Tetra(hexa)azacyclopenta[a]anthracenes, Tetraazaindeno[5,4-b]fluorenes, and Oxatetraazacyclopenta[m]tetraphenes

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    Multicomponent reactions (MCRs) are envisaged as an entry point for the synthesis of heterocyclic compounds with interesting biological activities. An efficient approach to annelated tetra(hexa)azacyclopenta[a]anthracenes, tetraazaindeno[5,4-b]fluorenes, and oxatetraazacyclopenta[m]tetraphene was accomplished using a three-component reaction involving 7-amino-2-methyl-3-phenylpyrazolo[1,5-a]pyrimidin-5-one with aromatic aldehydes and the corresponding active 1,3-dicarbonyl compounds (namely, dimedone, 1,3-dimethylbarbituric acid, 1,3-indanedione, and 4-hydroxycoumarine). The reactions were conducted in glacial acetic acid at reflux for 5 h to give the desired products in good yields (62–83 %). The chemical constitutions of all new products were confirmed spectroscopically

    Factors Affecting Traffic Accidents Density on Selected Multilane Rural Highways

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    Estimations of average crash density as a function of traffic elements and characteristics can be used for making good decisions relating to planning, designing, operating, and maintaining roadway networks. This study describes the relationships between total, collision, turnover, and runover accident densities with factors such as hourly traffic flow and average spot speed on multilane rural highways in Iraq. The study is based on data collected from two sources: police stations and traffic surveys. Three highways are selected in Wassit governorate as a case study to cover the studied locations of the accidents. Three highways are selected in Wassit governorate as a case study to cover the studied locations of the accidents. The selection includes Kut–Suwera, Kut–ShekhSaad, and Kut–Hay multilane divided highways located in the south of Iraq. The preliminary presentation of the studied highways was performed using Geographic Information System (GIS) software. Data collection was done to obtain crash numbers and types over five years with their locations, hourly traffic flow, and average spot speed and define roadway segments lengths of crash locations. The cumulative speed distribution curves introduce that the spot speed spectrum for each highway's whole traffic extends over a relatively wide range, indicating a maximum speed of 180 kph and a minimum speed of 30 kph. Multiple linear regression analysis is applied to the data using SPSS software to attain the relationships between the dependent variables and the independent variables to identify elements strongly correlated with crash densities. Four regression models are developed which verify good and strong statistical relationships between crash densities with the studied factors. The results show that traffic volume and driving speed have a significant impact on the crash densities. It means that there is a positive correlation between the single factors and crash occurrence. The higher volumes and the faster the driving speed, the more likely it is to crash. As the hourly traffic flow of automobile grows, the need for safe traffic facilities also extended. Doi: 10.28991/cej-2021-03091719 Full Text: PD

    Parameter Genetik Sifat Pertumbuhan Dan Kerapatan Kayu Klon Eucalyptus Pellita F. Muell. Di Dua Tapak Yang Berbeda Di Kalimantan Timur

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    Industrial forest plantations have an important role in fulfilling the wood demand. Based on global industrial development, the forest plantations industry will increase in the following years. Eucalyptus pellita has become main species in Indonesia forest plantations because it has a short cycle and wood products are suitable to forest industry. The average productivity of E. pellita plantations in Indonesia is still low and high variation. In an effort to increase the productivity, the first step is a better understanding of genetic control on growth and basic density. This study aims to determine the genetic parameters for growth and basic density of E. pellita clones on two different sites. The clonal trials was conducted at two different sites. Both clonal trial are designed using RCBD. The number of clones tested in both trial was 30, 5 blocks and 25 tree/plot. The result of the study showed that the effects of clones vary greatly according the enviromental conditions. The clones- environemntal interaction of growth trait is higher than the basic density. This is in line with genetic parameters of growth trait that are less stable than the basic density. The expected genetic gain of growth trait is higher than the basic density and at the same time there was a weak genetic correlation (there is even a negative) between growth trait and basic density. Therefore carefulness is needed in selecting clones when the two traits are used as selection parameters

    Synthesis of quinone-based heterocycles of broad-spectrum anticancer activity

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    A synthesis of benzo[e][1,2,4]triazines and 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones has been developed from reactions of amidrazones with 2-chloro-1,4-benzoquinone in EtOAc containing 0.5 mL of piperidine. This highly regioselective and one-pot process provided rapid access to 1,2,4-triazolospiro[4,5]deca-2,6,9-trien-8-ones (60%–70%) and benzo[e][1,2,4]triazines (11%–18%). On reacting amidrazones with 5-hydroxy-1,4-naphthoquinone in an EtOAc/piperidine mixture, the reaction proceeded to give 5-hydroxy-2-(piperidin-1-yl)naphthalene-1,4-dione. The structures of the isolated products were proved by infrared, NMR (2D-NMR), mass spectra, and elemental analyses in addition to X-ray structure analysis. The reaction mechanisms are discussed. The anticancer screening of selected compounds showed broad-spectrum anticancer activity against most melanoma cancer cell lines, ovarian cancer OVCAR-3, central nervous system cancer SF-295 and U251, non-small cell lung cancer NCI-H23, renal cancer SN12C, and colon cancer HCT-15 and HCT-116. The selected compounds exhibited moderate to weak anticancer activity to other cell lines
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