338 research outputs found
Efficienty of CFRP sheets in upgrading and/or strengthening square reinforced concrete columns
No full textStrengthening and/or upgrading reinforced concrete columns through utilization of composite sheets is now receiving wide acceptance worldwide. The technique is simple to use and has many advantages over other available methods. However, limited data is available about its efficiency in confining non-cylindrical shape columns. In this paper, the influence of using different schemes of wrapping of carbon fibre reinforced polymer (CFRP) sheets on the behaviour of reinforced concrete columns with and without utilizing
mechanical anchoring system is reported. The columns were 300 × 300 mm in cross section and 2005 mm in height and were subjected to incremental monotonic loading until complete failure. Test results indicated that the horizontally aligned CFRP sheets had more contribution to enhancing the ductility of the columns than the strength whereas the vertically aligned sheets had more contribution to increasing the column's ultimate capacity. The results also showed that both ductility and strength of the wrapped columns can be significantly increased by utilizing mechanical anchoring system that reduces the
distance between the unsupported nodal points for the sheets.Corresponding Author:
Prof. Saleh H. Alsayed, Civil Engineering Department, Department of Civil Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia. Email: [email protected]
Non-linear finite element analysis for RC elements subjected to in-plane loads
No full textCivil Engineering Department, College of Engineering, King Saud University.
Riyadh, 11421, Saudi ArabiaA non-linear iterative solution of finite element formulation implemented a 486 personal computer for predicting the cracking shapes and their propagation in reinforced concrete elements subjected to in-plane stresses is presented. The model is based on a smeared crack representation and a plane stress state simulation. It considers the influence of concrete tension stiffening after cracking, compressive stress degradation due to cracking, and single and double crack conditions. The reliability of the model is checked against the experimental results for specimens that were tested by the author as well as those tested by other researchers. Comparisons of the results show that the proposed model predicts the measured results with an overall average error of 2% and a coefficient of variation of 1.48. This work forms an effective tool for investigation of inelastic behavior of a concrete and reinforcing bar composite
Analisis Kodikologi dalam Manuskrip Al-Falaqiyah Karangan K. H. M. Burkan Saleh Kerinci
No full textArtikel ini membahas tentang naskah kitab Al-Falaqiyah karya K.H.M Burkan Saleh ditinjau dari masalah fisik naskah, kolofon: analisis kodikologi. Penelitian ini diawali dengan analisis kodikologi naskah yang menjelaskan tentang gambaran umum naskah kitab Al-Falaqiyah baik dari segi sejarah naskah, tempat penyimpanan naskah, tempat penulisan naskah atau penyalinan naskah, mempelajari seluk beluk fisik naskah. Metode penelitian yang digunakan dalam penelitian ini adalah kualitatif, yaitu penulis terjun langsung ke lokasi tempat penyimpanan naskah K.H.M Burkan Saleh, dengan menggunakan metode deskriptif analisis, yaitu menggambarkan objek yang diteliti dengan apa adanya sesuai dengan data-data yang diperoleh, mengumpulkan data melalui teknik wawancara, dokumentasi. Selain itu, penulis juga menggunakan studi kepustakaan dengan mencari jurnal, artikel, buku-buku yang berkaitan dengan tema penelitian. Berdasarkan penelitian ini, penulis menemukan bahwa ilmu falakiah berhasil menyentuh wilayah Kerinci yang dikembangkan oleh K.H. M Burkan Saleh di desa Tanjung Pauh pada tahun 1937 yang ditulisnya di Pondok Pesantren Madrasah Jauhar al-Islami, Tanjung Juhur, Jambi, kini manuskripnya diwariskan kepada anak dan menantunya Darti dan Rasidin di Tanjung Pauh Mudik, yang merupakan dosen IAIN Kerinci.
Abstract
This article discusses the manuscript of kitab Al-Falaqiyah by K. H. M. Burkan Saleh in terms of the physical problems of the manuscript, colophon and its relevance as a historical source: codicology analysis, this research begins with a codicoly analysis of a manuscript that explains the general description of the manuscript of kitab Al-Falaqiyah both in terms of the history of the manuscript, the place where the manuscript is stored, the place of writing the manuscript or copying the manuscript, studying the physical ins and outs of the manuscript. The research method used in this research is qualitative, namely, the author goes directly to the location where the manuscript of K.H.M Burkan Saleh is stored, using the descriptive analysis method, namely describing the object under study as it is in accordance with the data obtained, collecting data through interview techniques, documentation. In addition, the author also uses literature studies by looking for journals, articles, books related to the research theme. Based on this research, the author found that the science of falakiah successfully touched the Kerinci region developed by K.H. M Burkan Saleh in Tanjung Pauh village in 1937 which he wrote at the Islamic Boarding School Madrasah Jauhar al-Islami, Tanjung Juhur, Jambi, now his manuscript was inherited to his son and son-in-law Darti and Rasidin in Tanjung Pauh Mudik, who is a lecturer at IAIN KerinciArtikel ini membahas tentang naskah kitab Al-Falaqiyah karya K.H.M Burkan Saleh ditinjau dari masalah fisik naskah, kolofon: analisis kodikologi. Penelitian ini diawali dengan analisis kodikologi naskah yang menjelaskan tentang gambaran umum naskah kitab Al-Falaqiyah baik dari segi sejarah naskah, tempat penyimpanan naskah, tempat penulisan naskah atau penyalinan naskah, mempelajari seluk beluk fisik naskah. Metode penelitian yang digunakan dalam penelitian ini adalah kualitatif, yaitu penulis terjun langsung ke lokasi tempat penyimpanan naskah K.H.M Burkan Saleh, dengan menggunakan metode deskriptif analisis, yaitu menggambarkan objek yang diteliti dengan apa adanya sesuai dengan data-data yang diperoleh, mengumpulkan data melalui teknik wawancara, dokumentasi. Selain itu, penulis juga menggunakan studi kepustakaan dengan mencari jurnal, artikel, buku-buku yang berkaitan dengan tema penelitian. Berdasarkan penelitian ini, penulis menemukan bahwa ilmu falakiah berhasil menyentuh wilayah Kerinci yang dikembangkan oleh K.H. M Burkan Saleh di desa Tanjung Pauh pada tahun 1937 yang ditulisnya di Pondok Pesantren Madrasah Jauhar al-Islami, Tanjung Juhur, Jambi, kini manuskripnya diwariskan kepada anak dan menantunya Darti dan Rasidin di Tanjung Pauh Mudik, yang merupakan dosen IAIN Kerinci.
Abstract
This article discusses the manuscript of kitab Al-Falaqiyah by K. H. M. Burkan Saleh in terms of the physical problems of the manuscript, colophon and its relevance as a historical source: codicology analysis, this research begins with a codicoly analysis of a manuscript that explains the general description of the manuscript of kitab Al-Falaqiyah both in terms of the history of the manuscript, the place where the manuscript is stored, the place of writing the manuscript or copying the manuscript, studying the physical ins and outs of the manuscript. The research method used in this research is qualitative, namely, the author goes directly to the location where the manuscript of K.H.M Burkan Saleh is stored, using the descriptive analysis method, namely describing the object under study as it is in accordance with the data obtained, collecting data through interview techniques, documentation. In addition, the author also uses literature studies by looking for journals, articles, books related to the research theme. Based on this research, the author found that the science of falakiah successfully touched the Kerinci region developed by K.H. M Burkan Saleh in Tanjung Pauh village in 1937 which he wrote at the Islamic Boarding School Madrasah Jauhar al-Islami, Tanjung Juhur, Jambi, now his manuscript was inherited to his son and son-in-law Darti and Rasidin in Tanjung Pauh Mudik, who is a lecturer at IAIN Kerinc
Influence of severe hot-dry climate on the mechanical properties of fibrous reinforced concrete beams
No full textThis paper presents the results of the work carried out to study the influence of curing environment and steel fiber volume fraction on the flexural strength, flexural rigidity, flexural toughness, and ductility of fibrous reinforced concrete (RC) beams. A total of twenty simply supported beams were tested. Ten of the twenty beams were cured under controlled laboratory conditions and the other ten were cured under severe hot dry climate (SHDC) characterized by their intense heat, Iow relative humidity, direct solar radiation, and large diurnal variations of daily temperatures. Tests were carried out 28 and 90 days after casting. Test results show that for non fibrous RC concrete beams the adverse effects of SHDC have more influence in reducing the flexural toughness than the flexural strength. On the other hand, test results indicate that under any of the two curing environment considered in this study, the flexural strength, flexural rigidity, flexural toughness and ductility of the fibrous RC beams are in direct proportion with the fiber content. Moreover, the results reveal that the enhancements in these engineering properties due to the steel fiber addition are not affected by the above described severe field conditions. Furthermore, inclusion of steel fibers in concrete helps, to some extent, in reducing the adverse effects of SHDC on the properties of concrete
Flexural deflection of reinforced fibrous concrete beams
No full textThe results of tests on 10 reinforced concrete beams with and without steel fiber reinforcement are presented. A simple empirical equation to estimate deflection of the reinforced concrete beams is derived from the test observations. The model accounts for the aspect ratio and the volume fraction of the steel fibers. The mean and the coefficient of variation of the ratio of the measured to the calculated deflections, for the design-to-cracked moment ratios in the range of 1 to 4.5, are 99 and 8.2 percent, respectively. The model also well estimated the deflections measured by other researchers
Visceral afferent stimulation-evoked changes in the release of peptides into the parabrachial nucleus in vivo
No full textPrevious investigations have demonstrated that the peptides substance P (SP), calcitonin gene-related peptide (CGRP), cholecystokinin (CCK), neurotensin (NT) and somatostatin (SOM) significantly modulate the glutamate-mediated transmission of visceral information through the parabrachial nucleus (PBN) to the ventrobasal thalamus. In addition, we have shown that the staining intensity of SOM, CCK and NT in the PBN decreases significantly following 2 h of vagal stimulation as visualized using immunohistochemistry. As well, the staining intensity of both SP and CGRP in the PBN were shown to increase under similar conditions. The present investigation was done to determine whether the altered peptide staining intensity of these peptides observed following 2 h of vagal stimulation was the result of an altered peptide release from terminals within the PBN. Male Sprague-Dawley rats were anesthetized with sodium thiobutabarbitol and instrumented to record blood pressure and heart rate and for the stimulation of the cervical vagus nerve. A push-pull perfusion cannula was lowered into the region of the PBN for the continuous sampling of extracellular fluid. Radioenzymatic quantification of the perfusates for peptide content revealed that the extracellular fluid concentration of CGRP and SP increased significantly during the 2 h of vagal stimulation. When the vagal stimulation was terminated, the release of both CGRP and SP decreased significantly below prestimulated values for approximately 30 min before returning to prestimulated levels shortly thereafter. In contrast, there was a significant decrease in the release of CCK, SOM and NT into the PBN during the period of vagal stimulation. Extracellular perfusate levels of these peptides returned to normal upon termination of stimulation. These results demonstrate that terminal release of CGRP and SP is significantly increased and terminal release of CCK, SOM and NT is significantly decreased in the PBN during 2 h of vagal stimulation. These results are consistent with our previous finding that the immunohistochemical staining intensity of CGRP and SP is increased while that of CCK, SOM and NT is decreased following vagal stimulation.LR: 20031114; PUBM: Print; JID: 0045503; 0 (Neuropeptides); 33507-63-0 (Substance P); 39379-15-2 (Neurotensin); 51110-01-1 (Somatostatin); 83652-28-2 (Calcitonin Gene-Related Peptide); 9011-97-6 (Cholecystokinin); ppublishSource type: Electronic(1
Ischemic tolerance following low dose NMDA involves modulation of cellular stress proteins
No full textMild NMDA receptor activation is correlated with neuroprotection in models of cerebral ischemia. Neuroprotection with NMDA manifests as a form of ischemic tolerance and involves the induction of cellular stress systems sensitive to disturbances in cellular calcium homeostasis. Unilateral micro-injection of 10, 160 and 320 microM NMDA into the prefrontal cortex of a rat 30 min prior to permanent occlusion of the middle cerebral artery (MCAO) significantly reduced the area of infarct observed after 4 h of ischemia. The highest dose of NMDA (320 microM) prevented the propagation of ischemic damage through a direct toxicity on neuronal tissue adjacent to the injection site as demonstrated in thionin-stained sections. As a result, the degree of ischemia-induced damage was similar to that measured in rats pretreated with the low dose of NMDA (10 microM). Expression of heat shock protein (HSP) 70 and glucose-regulated protein (GRP) 94 in cortical samples taken from the region of infarct following MCAO was significantly reduced in rats pretreated with 10 microM NMDA compared to saline-injected control rats and rats pretreated with higher doses of NMDA. Furthermore, 10 microM NMDA did not appear to influence expression of m-calpain or GRP78, however, higher doses of NMDA did significantly induce expression of both proteins as assessed by Western blotting. In summary, our data demonstrate an in vivo rodent model of ischemic tolerance in which 30 min of neuronal preconditioning with 10 microM NMDA confers protection against a 4 h period of MCAO-induced ischemia. This effect may involve modulation of cellular stress signals, in particular HSP70 and GRP94.Accession Number: 18992720 Language: English. Date Created: 20081216. Update Code: 20081218. Publication Type: Journal Article; Research Support, Non-U.S. Gov't. Journal ID: 0045503. Publication Model: Print-Electronic. Cited Medium: Internet. NLM ISO Abbr: Brain Res.Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=cmedm&AN=18992720&loginpage=login.asp&site=ehost-liv
Estrogen blocks the cardiovascular and autonomic changes following vagal stimulation in ovariectomized rats
No full textThe current investigation examines the effect of acute and chronic estrogen administration on baroreflex sensitivity and autonomic tone following 2 h of vagal afferent stimulation in ovariectomized female rats. Female Sprague-Dawley rats were ovariectomized and supplemented daily for 7 days with either estrogen (OVX-E2; 0.5 microg/kg; s.c.) or saline (OVX-S; 0.9%; s.c.). On the 8th day the animals were anaesthetized (sodium thiobutabarbitol; 100 mg/kg) and instrumented for recording blood pressure, heart rate and efferent vagal and renal nerve activities. The baroreflex was evoked using intravenous injection of various doses of phenylephrine hydrochloride (0.025, 0.05+/-0.1 mg/kg). Electrical stimulation of vagal afferents for 2 h produces autonomic imbalance characterized by sympathoexcitation and parasympathetic withdrawal. This protocol of vagal stimulation produced a significant increase in renal nerve activity (from 20+/-6 to 140+/-20 spikes/2 s) and decreases in both vagal nerve activity (from 22+/-3 to 10+/-2 spikes/2 s) and baroreflex sensitivity (from 0.55+/-0.05 to 0.3+/-0.05) in OVX-S female rats. However. vagal stimulation had no effect on baroreflex sensitivity or autonomic nerve activities in OVX-E2 rats. Administration of a single, bolus dose of estrogen (1 x 10(-2) mg/kg) to OVX-S rats immediately prior to termination of vagal stimulation blocked the changes in autonomic nerve activities and baroreflex sensitivity previously observed. These results suggest that both chronic and acute estrogen supplementation may provide resistance to the autonomic disturbances associated with visceral afferent activation.LR: 20061115; PUBM: Print; JID: 100909359; 50-28-2 (Estradiol); 7647-14-5 (Sodium Chloride); ppublishSource type: Electronic(1
Apocynin may limit total cell death following cerebral ischemia and reperfusion by enhancing apoptosis
No full textThe present study was designed to determine a dose-response relationship between apocynin and infarct volume as well as to provide a possible molecular mechanism mediating this effect. We tested the hypothesis that apocynin protects against cell death following stroke and reperfusion injury. Apocynin was administered 30min prior to, or immediately following removal of sutures used to occlude the middle cerebral artery (MCA) in male Sprague-Dawley rats. Following removal of the sutures, the MCA was allowed to undergo 5.5h of reperfusion. Pretreatment with apocynin 30min prior to occlusion resulted in a dose-dependent reduction in infarct volume by approximately 50 %. Analysis of tissue from the ischemic cortex of apocynin-treated rats showed an increase in the level of glutathione (GSH), protein adducts (HNE-His), hydrogen peroxide (H(2)O(2)) and DNA fragmentation (apoptotic cell death) was also observed. This suggests that apocynin may increase antioxidant defense systems (GSH) to limit the degree of ischemia-induced cellular stress. In addition, this moderate cell stress results in more apoptotic vs necrotic cell death, and thus may limit the spreading depression and total cell death that occurs following ischemia/reperfusion. These effects may serve as a potential novel mechanism of action contributing to the apocynin-induced neuroprotection observed.CI: Copyright (c) 2011; JID: 8207483; 2011/08/01 [received]; 2011/09/08 [revised]; 2011/09/10 [accepted]; aheadofprintSource type: Electronic(1
17beta-Estradiol release in the parabrachial nucleus of the rat evoked by visceral afferent activation
No full textIn the present investigation, in vivo microdialysis was used to measure the concentration of estrogen in the parabrachial nucleus (PBN) and plasma of male and ovariectomized female Sprague-Dawley rats supplemented with either estrogen (OVX-E(2)) or saline (OVX-S) following visceral afferent activation. Analysis of dialysate samples prior to vagal stimulation and in non-stimulated controls revealed a continuous concentration of estrogen in the PBN for all treatment groups (male, 38 +/-4 pg ml(-1); OVX-E(2), 38+/-5 pg ml(-1); OVX-S, 33 +/- 4 pg ml(-1)). This concentration of estrogen in the PBN was significantly increased during vagal stimulation in all groups (male, 64+/-4 pg ml(-1); OVX-E(2), 104+/-9 pg ml(-1); OVX-S, 80+/-6 pg ml(-1); P<0.05) and returned to pre-stimulation values within 2 h following termination of the stimulation. Immunohistochemical analysis revealed that estrogen receptor (ERalpha and ERbeta) density in males and ovariectomized saline-replaced female rats was significantly lower than that of estrogen-replaced female rats. These results suggest that estrogen is released into the PBN by an increase in visceral afferent traffic, however, alterations in estrogen receptor populations in the PBN may contribute to an attenuated physiological role of estrogen in the PBN of male and saline-replaced ovariectomized female rats.LR: 20061115; PUBM: Print; JID: 7500844; 0 (Receptors, Estrogen); 50-28-2 (Estradiol); 58-22-0 (Testosterone); ppublishSource type: Electronic(1
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