Search results for: induced resistance

Authors: Vania Helena Tonussi Vidal, Ester Eliane Jeunon

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This article aims to analyze the change processes of management related bureaucracy and learning organization model. The theoretical framework was based on Beer and Nohria (2001) model, identified as E and O Theory. Based on this theory the empirical research was conducted in connection with six key dimensions: goal, leadership, focus, process, reward systems and consulting. We used a case study of an educational Institution located in Barbacena, Minas Gerais. This traditional center of technical knowledge for long time adopted the bureaucratic way of management. After many changes in a business model, as the creation of graduate and undergraduate courses they decided to make a deep change in management model that is our research focus. The data were collected through semi-structured interviews with director, managers and courses supervisors. The analysis were processed by the procedures of Collective Subject Discourse (CSD) method, develop by Lefèvre & Lefèvre (2000), Results showed the incremental growing of management model toward a learning organization. Many impacts could be seeing. As negative factors we have: people resistance; poor information about the planning and implementation process; old politics inside the new model and so on. Positive impacts are: new procedures in human resources, mainly related to manager skills and empowerment; structure downsizing, open discussions channel; integrated information system. The process is still under construction and now great stimulus is done to managers and employee commitment in the process.

Keywords: bureaucracy, organizational learning, organizational change, E and O theory

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Authors: Jerome E. Abiemo, Takeshi Mizunoya

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The Aveyime community in the Volta region of Ghana is one of the major hubs for rice production. In the past, rice farmers applied organic pesticides to control pests, and compost as a soil amendment to improve fertility and productivity. However, the introduction of chemical pesticides and fertilizers have led many farmers to convert to inorganic system of rice production, without considering the social costs (e.g. groundwater contamination and health costs) related to the use of pesticides. The study estimates and compares the private and social BCRs of organic and inorganic systems of rice production. Both stratified and simple random sampling techniques were employed to select 300 organic and inorganic rice farmers and 50 pesticide applicators. The respondents were interviewed with pre-tested questionnaires. The Contingent Valuation Method (CVM) which elucidates organic farmers` Willingness-to-Pay (WTP) was employed to estimate the cost of groundwater contamination. The Cost of Illness (COI) analysis was used to estimate the health cost of pesticide-induced poisoning of applicators. The data collated, was analyzed with the aid of Microsoft excel. The study found that high private benefit (e.g. increase in farm yield and income) was the most influential factor for the rapid adoption of pesticides among rice farmers. The study also shows that the social costs of inorganic rice production were high. As such the social BCR of inorganic farming (0.2) was low as compared to organic farming (0.7). Based on the results, it was recommended that government should impose pesticide environmental tax, review current agricultural policies to favour organic farming and promote extension education to farmers on pesticide risk, to ensure agricultural and environmental sustainability.

Keywords: benefit-cost-ratio (BCR), inorganic farming, pesticides, social cost

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Authors: Neeraj Malhotra, Ramya Shenoy

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Objective: To assess the effect of clinical parameters (bonding agent, preparation design & storage media) on the strength of reattached anterior tooth fragment. Methodology: This is a systematic review and meta-analysis for articles referred from MEDLINE, PUBMED, and GOOGLE SCHOLAR. The articles on tooth reattachment and clinical factors affecting fracture strength/bond strength/fracture resistance of the reattached tooth fragment in anterior teeth and published in English from 1999 to 2016 were included for final review. Results: Out of 120 shortlisted articles, 28 articles were included for the systematic review and meta-analysis based on 3 clinical parameters i.e. bonding agent, tooth preparation design & storage media. Forest plot & funnel plots were generated based on individual clinical parameter and their effect on strength of reattached anterior tooth fragment. Results based on analysis suggest combination of both conclusive evidence favoring the experimental group as well as in-conclusive evidence for individual parameter. Conclusion: There is limited evidence as there are fewer articles supporting each parameter in human teeth. Bonding agent had showed better outcome in selected studies.

Keywords: bonding agent, bond strength, fracture strength, preparation design, reattachment, storage media

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Authors: Adedoyin Akintunde Adedayo, Onilude Abiodun Anthony

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The continuous usage of synthetic antibiotics in livestock production has led to the resistance of microbial pathogens. This has prompted research to find alternative sources. This study aims to compare the growth and intestinal health of broilers fed scent leaf meal (SLM) as an alternative to synthetic antibiotics. The study used a completely randomized design (CRD) with 300 one-week-old Arbor Acres broiler chicks. The chicks were divided into six treatments with five replicates of ten birds each. The feeding trial lasted 49 days, including a one-week acclimatization period. Commercial broiler diets were used. The diets included a negative control (no leaf meal or antibiotics), a positive control (0.10% oxy-tetracycline), and four diets with different levels of SLM (0.5%, 1.0%, 1.5%, and 2.0%). The supplementation of both oxy-tetracycline and SLM improved feed intake during the finisher phase. Birds fed SLM at a 1% inclusion level showed significantly (P<0.05) improved average body weight gain (ABWG), lowered feed-to-gain ratio, and cost per kilogram of weight gain compared to other diets. The mortality (2.0%) rate was significantly higher in the negative control group. White blood cell levels varied significantly (P<0.05) in birds fed SLM-supplemented diets, and the use of 2% SLM led to an increase in liver weight. However, welfare indices were not compromised.

Keywords: Arbor Acres, phyto-biotic, synthetic antibiotic, white blood cell, liver weight

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Authors: Aastha Agarwal, Veena Sharma

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N-nitrosopyrollidine or NPYR is a tobacco-specific nitrosamine which upon intoxicated causes abnormal production of Reactive Oxygen Species disrupt the endogenous antioxidant system. The study was designed to evaluate the histological changes in lung tissue of Mus musculus in NPYR administered lungs and effect of isolated flavonoid 3,6-dihydroxy-(3’,4’,7’-trimethoxyphenyl)-chromen-4-one-7-glucoside (ITC) from experimental plant Indigofera tinctorial. Post treatment with isolated compound significantly restored the abnormal symptoms and changes in pulmonary tissue. Transverse section of mouse lung in control animals appeared as a thin lace. Histologically, most of the lung was arranged as alveoli which were thin walled structures made up of single layered squamous epithelial cells. In the transverse section of lung at 100 X will clearly show the component of alveoli, surround by a thin layer of connective tissue and blood vessels. Smaller bronchioles were lined by cuboidal epithelial cells while larger bronchioles were lined by ciliated columnar epithelium layer while in NPYR intoxicated lungs signs of vast pulmonary damages and carcinogenesis as alveolar damage, necrosis, DADs or defused alveolar damages hyperplasia, metaplasia, dysplasia and next stage of carcinogenesis were revealed. Treatment with ITC showed the significant positive changes in the lung tissue due to the side hydroxyl and methoxy groups in its structure which help in combating oxidative injuries and give protection from the free radicals generated during the metabolism of NPYR in body. Thus, histopathological analysis confirms the development of the cancerous conditions in the lung tissue in mice model and the protective effects of ITC.

Keywords: flavonoid, histopathology, Indigofera tinctoria, lung

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Authors: Edison A. Bonifaz

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In this work, a numerical procedure is proposed to design dense multi-material structures using the Directed Energy Deposition (DED) process. A thermo-mechanical finite element model to predict thermal cycles and residual stresses is presented. A numerical layer build-up procedure coupled with a moving heat flux was constructed to minimize strains and residual stresses that result in the multi-layer deposition of an AISI 316 austenitic steel on an AISI 304 austenitic steel substrate. To simulate the DED process, the automated interface of the ABAQUS AM module was used to define element activation and heat input event data as a function of time and position. Of this manner, the construction of ABAQUS user-defined subroutines was not necessary. Thermal cycles and thermally induced stresses created during the multi-layer deposition metal AM pool crystallization were predicted and validated. Results were analyzed in three independent metal layers of three different experiments. The one-way heat and material deposition toolpath used in the analysis was created with a MatLab path script. An optimal combination of feedstock and heat input printing parameters suitable for fabricating multi-material dense structures in the directed energy deposition metal AM process was established. At constant power, it can be concluded that the lower the heat input, the lower the peak temperatures and residual stresses. It means that from a design point of view, the one-way heat and material deposition processing toolpath with the higher welding speed should be selected.

Keywords: event series, thermal cycles, residual stresses, multi-pass welding, abaqus am modeler

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Authors: Allaeddine Athmani, Abdelhacine Gouasmia, Tiago Ferreira, Romeu Vicente

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Seismic vulnerability assessment of masonry buildings is a fundamental issue even for moderate to low seismic hazard regions. This fact is even more important when dealing with old structures such as those located in Annaba city (Algeria), which the majority of dates back to the French colonial era from 1830. This category of buildings is in high risk due to their highly degradation state, heterogeneous materials and intrusive modifications to structural and non-structural elements. Furthermore, they are usually shelter a dense population, which is exposed to such risk. In order to undertake a suitable seismic risk mitigation strategies and reinforcement process for such structures, it is essential to estimate their seismic resistance capacity at a large scale. In this sense, two seismic vulnerability index methods and damage estimation have been adapted and applied to a pilot-scale building area located in the moderate seismic hazard region of Annaba city: The first one based on the EMS-98 building typologies, and the second one derived from the Italian GNDT approach. To perform this task, the authors took the advantage of an existing data survey previously performed for other purposes. The results obtained from the application of the two methods were integrated and compared using a geographic information system tool (GIS), with the ultimate goal of supporting the city council of Annaba for the implementation of risk mitigation and emergency planning strategies.

Keywords: Annaba city, EMS98 concept, GNDT method, old city center, seismic vulnerability index, unreinforced masonry buildings

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Authors: Vasanth C. Shunmugasamy, Bilal Mansoor

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Magnesium alloys are increasingly being considered for structural systems across different industrial sectors, including precision components of biomedical devices, owing to their high specific strength, stiffness and biodegradability. However, Mg alloys exhibit a high corrosion rate that restricts their application as a biomaterial. For safe use as biomaterial, it is essential to control their corrosion rates. Mg alloy corrosion is influenced by several factors, such as grain size, precipitates and texture. In Mg alloys, microgalvanic coupling between the α-Mg matrix and secondary precipitates can exist, which results in an increased corrosion rate. The present research addresses this challenge by engineering the microstructure of a biodegradable Mg–Zn–RE–Zr alloy by friction stir processing (FSP), a severe plastic deformation process. The FSP-processed Mg alloys showed improved corrosion resistance and mechanical properties. FSPed Mg alloy showed refined grains, a strong basal texture and broken and uniformly distributed secondary precipitates in the stir zone. Mg, alloy base material, exposed to In vitro corrosion medium showed micro galvanic coupling between precipitate and matrix, resulting in the unstable passive layer. However, FS processed alloy showed uniform corrosion owing to stable surface film formation. The stable surface film is attributed to refined grains, preferred texture and distribution of precipitates. The research results show promising potential for Mg alloy to be developed as a biomaterial.

Keywords: biomaterials, severe plastic deformation, magnesium alloys, corrosion

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Authors: Aysegul Alyamac, Sukru Gulec

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Ankaferd Blood Stopper (ABS) is a plant extract used to stop bleeding caused by injuries and surgical interventions. ABS also involved in wound healing of intestinal mucosal damage due to oxidative stress and inflammation. Inflammatory Bowel Disease (IBD) is a common chronic disorder of the gastrointestinal tract that causes abdominal pain, diarrhea, and gastrointestinal bleeding, and increases the risk of colon cancer. Inflammation is an essential factor in the development of IBD. The various studies have been performed about the physiological effects of ABS; however, ABS dependent mechanism on colonic inflammation has not been elucidated. Thus, the protective effect of ABS on colonic inflammation was investigated in this study. The Caco-2 and RAW 264.7 murine macrophage cells were used as a model of in vitro colonic inflammation. RAW 264.7 cells were treated with lipopolysaccharide (LPS) for 12 hours to induce the inflammation, and a conditional medium was obtained. Caco-2 cells were treated with 15 µl/ml ABS for 4 hours, then incubated with conditional medium and the cells also were incubated with 15 µl/ml ABS and conditional medium together for 4 hours. Tumor necrosis factor alpha (TNF-α) protein levels were targeted in testing inflammatory condition and its level was significantly increased (25 fold, p<0.001) compared to the control group by using Enzyme-Linked Immunosorbent Assay (ELISA) method. The COX-2 mRNA level was used as a marker gene to show the possible anti-inflammatory effect of ABS in Caco-2 cells. RAW cells-derived conditional medium significantly (3.3 fold, p<0.001) induced cyclooxygenase-2 (COX-2) mRNA levels in Caco-2 cells. The pretreatment of Caco-2 cells caused a significant decrease (3.3 fold, p<0.001) in COX-2 mRNA levels relative to conditional medium given group. Furthermore, COX-2 mRNA level was significantly reduced (4,7 fold, p<0.001) in ABS and conditional medium treated group. These results suggest that ABS might have an anti-inflammatory effect in vitro.

Keywords: Ankaferd blood stopper, CaCo-2, colonic inflammation, RAW 264.7

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Authors: Irma Gabriela Lopez-Moreno, Elva Perez-Luque, Herlinda Aguilar-Zavala

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Introduction: Type 2 Diabetes Mellitus (T2DM) is characterized by combination of insulin resistance and deterioration of insulin secretion. Sfrp5 is a protein that antagonizes Wnt5a proteins by preventing it from reaching its receptor and activating the Wnt/β-catenin signaling pathway, this pathway is one of the most important regulators of adipogenesis. Although metformin decreases glucose levels its mechanisms of action are not fully known but it has been implicated in the inhibition of the Wnt/β-catenin signaling pathway. Objective: The objective was evaluating the effects of metformin on serum levels of Sfrp5 in patients with T2DM treated and not treated with metformin. Methods: Two groups of patients were selected: one group of T2DM patients treated with metformin (n = 35) and another group of subjects with recent diagnosis of T2DM untreated (n = 35) with a mean age of 48 ± 9 years. In these subjects anthropometric measures were taken as weight, height, waist and hip circumference, were calculated the percentage of body fat, visceral fat and muscle mass. In addition, were measured glucose levels, lipid profile, adiponectin and Sfrp5. Results: Sfrp5 were higher in metformin-treated patients compared to the untreated group (19.9 vs 13.6 ng/mL p < 0.001), a negative correlation was found between Sfrp5 levels and total cholesterol levels (r= -0.25, p = 0.03) and percentage of visceral fat (r = -0.26, p = 0.03) and a positive correlation with HDL cholesterol levels (r = 0.31, p = 0.01) and adiponectin (r=0.65, p = < 0.001). Conclusions: The findings show that metformin consumption increased levels of Sfrp5, which may lead to a decrease in the activation of the WNT/β-catenin pathway impacting on adipogenesis.

Keywords: adiponectin, diabetes, metformin, Sfrp5

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Authors: Victor Hugo Sanchez Rodriguez

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Amidst the challenges posed by pandemic-induced lockdowns, traditional educational models have been disrupted. To bridge the distance learning gap, our project introduces an innovative initiative focused on teaching high school students basic biotechnology techniques. We aim to empower young minds and foster curiosity by encouraging students to create their own DIY biotechnology laboratories using easily accessible materials found at home. This abstract outlines the key aspects of our project, highlighting its importance, methodology, and evaluation approach.In response to the pandemic's limitations, our project targets the delivery of biotechnology education at a distance. By engaging students in hands-on experiments, we seek to provide an enriching learning experience despite the constraints of remote learning. The DIY approach allows students to explore scientific concepts in a practical and enjoyable manner, nurturing their interest in biotechnology and molecular biology. Originally designed to assess professional-level research programs, we have adapted the URSSA to suit the context of biotechnology and molecular biology synthesis for high school students. By applying this tool before and after the experimental sessions, we aim to gauge the program's impact on students' learning experiences and skill development. Our project's significance lies not only in its novel approach to teaching biotechnology but also in its adaptability to the current global crisis. By providing students with a stimulating and interactive learning environment, we hope to inspire educators and institutions to embrace creative solutions during challenging times. Moreover, the insights gained from our evaluation will inform future efforts to enhance distance learning programs and promote accessible science education.

Keywords: DIY biotechnology, high school students, distance learning, pandemic education, undergraduate research student self-assessment (URSSA)

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Authors: Abhaydeep Pandey, Shweta Shukla, Saptamita Goswami, Bhaswati Bandyopadhyay, Vishnampettai Ramachandran, Sudhanshu Vrati, Arup Banerjee

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Background: Long non-coding RNAs (lncRNAs) are the important regulators of gene expression and play important role in viral replication and disease progression. The role of lncRNA genes in the pathogenesis of Dengue virus-mediated pathogenesis is currently unknown. Methods: To gain additional insights, we utilized an unbiased RNA sequencing followed by in silico analysis approach to identify the differentially expressed lncRNA and genes that are associated with dengue disease progression. Further, we focused our study on lncRNAs NEAT1 (Nuclear Paraspeckle Assembly Transcript 1) as it was found to be differentially expressed in PBMC of dengue infected patients. Results: The expression of lncRNAs NEAT1, as compared to dengue infection (DI), was significantly down-regulated as the patients developed the complication. Moreover, pairwise analysis on follow up patients confirmed that suppression of NEAT1 expression was associated with rapid fall in platelet count in dengue infected patients. Severe dengue patients (DS) (n=18; platelet count < 20K) when recovered from infection showing high NEAT1 expression as it observed in healthy donors. By co-expression network analysis and subsequent validation, we revealed that coding gene; IFI27 expression was significantly up-regulated in severe dengue cases and negatively correlated with NEAT1 expression. To discriminate DI from dengue severe, receiver operating characteristic (ROC) curve was calculated. It revealed sensitivity and specificity of 100% (95%CI: 85.69 – 97.22) and area under the curve (AUC) = 0.97 for NEAT1. Conclusions: Altogether, our first observations demonstrate that monitoring NEAT1and IFI27 expression in dengue patients could be useful in understanding dengue virus-induced disease progression and may be involved in pathophysiological processes.

Keywords: dengue, lncRNA, NEAT1, transcriptome

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Authors: M. Cabuk, M. Yavuz, T. A. Yesil, H. I. Unal

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Electrorheological (ER) fluids are a class of smart materials exhibiting reversible changes in their rheological and mechanical properties under an applied electric field (E). ER fluids generally are composed of polarisable solid particles dispersed in non-conducting oil. ER fluids are fluids which exhibit. The resistance to motion of the ER fluid can be controlled by adjusting the applied E, due to their fast and reversible changes in their rheological properties presence of E. In this study, a series of chitosan/expanded perlite (CS/EP) composites with different chitosan mass fractions (10%, 20%, and 50%) was used. Characterizations of the composites were carried out by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) techniques. Antisedimentation stability and dielectric properties of the composites were also determined. The effects of volume fraction, electric field strength, shear rate, shear stress, and temperature onto ER properties of the CS/EP composite particles dispersed in silicone oil (SO) were investigated in detail. Vibration damping behavior of the CS/EP composites were determined as a function of frequence, storage (Gʹ) and loss (Gʹ ʹ) moduli. It was observed that ER response of the CS/EP/SO ER fluids increased with increasing electric field strength and exhibited the typical shear thinning non-Newtonian viscoelastic behaviors with increasing shear rate. The maximum yield stress was obtained with 1250 Pa under E = 3 kV/mm. Further, the CS/EP/SO ER fluids were observed to sensitive to vibration control by showing reversible viscosity enhancements (Gʹ > Gʹ ʹ). Acknowledgements: The authors thank the TÜBİTAK (214Z199) for the financial support of this work.

Keywords: chitosan, electrorheology, perlite, vibration control

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Authors: Fourar Ali, Fourar Fatima Zohra

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Knowledge of sediment characteristics is fundamental to understanding their sedimentary functioning: sedimentation, settlement, and erosion processes of cohesive sediments are controlled by complex interactions between physical, chemical, and biological factors. Sediment transport is of primary importance in river hydraulics and river engineering. Indeed, the displacement of sediments can lead to lasting modifications of the bed in terms of its elevation, slope and roughness. The protection of a bank, for example, is likely to initiate a local incision of the river bed, which, in turn, can lead to the subsidence of the bank. The flows in the natural environment occur in general with heterogeneous boundary conditions because of the distribution of the roughnesses of the fixed or mobile bottoms and of the important deformations of the free surface, especially for the flows with a weak draft considering the irregularity of the bottom. Bedforms significantly influence flow resistance. The arrangement of particles lining the bottom of the stream bed or experimental channel generates waveforms of different sizes that lead to changes in roughness and consequently spatial variability in the turbulent characteristics of the flow. The study which is focused on the laws of friction in alluvial beds, aims to analyze the characteristics of flows and materials constituting the natural channels. Experimental results were obtained by simulating these flows on a rough bottom in an experimental channel at the Hydraulics Laboratory of the University of Batna 2. The system of equations governing the problem is solved using the program named: CLIPPER.5 and ACP.

Keywords: free surface flow, heterogeneous sand, moving bottom bed, friction coefficient, bottom roughness

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Authors: Jennifer McNeill

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Over the years UK Governments have extended the use of welfare conditionality to more marginalised groups. Whereas in the past, disabled people’s rights to unconditional welfare were defended, significant numbers of disabled people have in recent years been re-classified as ‘fit for work’ as a result of this policy shift towards increased conditionality targeting more welfare service user groups. This paper discusses findings from a five-year project exploring the ethics and efficacy of welfare conditionality. Drawing on repeat interviews over three years with 58 disabled welfare service users across England and Scotland, the paper explores the experience of, and impact of conditionality upon, disabled participants. In particular, participants described the process of claiming disability-related benefits as stigmatising, with some describing the medical assessments as demeaning, traumatic and even painful. The medical assessments are conducted by private contractors and participants felt they were treated unfairly, under suspicion and under surveillance. This finding is important in line with a recent UN report concerned with the practice of such assessments. The findings reveal that notions of ‘deservedness’ are embedded in this system as disabled recipients argue for their entitlement to welfare claims relative to what are deemed to be less deserving groups of benefit claimants. This indicates an increasing competition ethic within different sections of the most marginalised social groups that facilitate further forms of social fragmentation, particularly in relation to opposition to benefit cuts and other changes requiring concerted and organised forms of resistance. The impact of media and political scapegoating of the most marginal has generated divisions within even those who position themselves as legitimate recipients.

Keywords: disability, medical assessments, stigma, welfare conditionality

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Authors: Navodit Goel, Prabir K. Paul

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Tomato (Solanum lycopersicum) is attacked by Pseudomonas syringae pv. tomato causing speck lesions on the leaves leading to severe economic casualty. In the present study, aqueous fruit extracts of Azadirachta indica (neem) were sprayed on a single node of tomato plants grown under controlled contamination-free conditions. The treatment of plants was performed with neem fruit extract either alone or along with the pathogen. The parameters of observation were activities of polyphenol oxidase (PPO) and lysozyme, and isoform analysis of PPO; both at the treated leaves as well as untreated leaves away from the site of extract application. Polyphenol oxidase initiates phenylpropanoid pathway resulting in the synthesis of quinines from cytoplasmic phenols and production of reactive oxygen species toxic to broad spectrum microbes. Lysozyme is responsible for the breakdown of bacterial cell wall. The results indicate the upregulation of PPO and lysozyme activities in both the treated and untreated leaves along with de novo expression of newer PPO isoenzymes (which were absent in control samples). The appearance of additional PPO isoenzymes in bioelicitor-treated plants indicates that either the isoenzymes were expressed after bioelicitor application or the already expressed but inactive isoenzymes were activated by it. Lysozyme activity was significantly increased in the plants when treated with the bioelicitor or the pathogen alone. However, no new isoenzymes of lysozyme were expressed upon application of the extract. Induction of resistance by neem fruit extract could be a potent weapon in eco-friendly plant protection strategies.

Keywords: Azadirachta indica, lysozyme, polyphenol oxidase, Solanum lycopersicum

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Authors: Ligia Nascimento, Manuela Faia Correia

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Nowadays, Information and Communication Technologies (ICT) are embedded in most professions. Technostress - or stress induced by the use of ICTs, has been studied in various sectors of activity and in different geographical areas, mainly from the perspective of its harmful impacts. In the context of work, the technological contexts capable of causing stress have been examined in-depth, as well as the type of individuals most likely to experience its negative effects. However, new lines of the research argue that the stress generated by the use of ICTs may not necessarily be detrimental (technodistress), admitting that, in contrast, and in addition, it may actually be beneficial to organizations and their employees (technoeustress). Any measures that succeed in reducing technodistress do not necessarily lead to the creation of technoeustress, justifying the study of this phenomenon in a focused and independent manner. Adopting the transactional model of stress as the basic theoretical framework, an ongoing research project aims to study technoeustress independently. Given the role played in the qualification and progress of society and the economy, it becomes particularly critical to care for the well-being of the higher education teacher. Particularly in recent times, when teleworking is prevalent, these professionals have made a huge, compulsive effort to adapt to a new teaching reality. Rather than limiting itself to mitigating adverse effects of ICT use, which featured earlier approaches, the present study seeks to understand how to activate the positive side of technostress in higher education teachers in order to obtain favorable personal and organizational outcomes from ICT use at work. The research model seeks to understand, upstream, the ICT characteristics that increase the perception of technoeustress among higher education teachers, studying the direct and moderating effects of individual and organizational variables and, downstream, the impacts that technoeustress has on job satisfaction and performance. This research contributes both to expanding the knowledge of the technostress phenomenon and to identify possible recommendations for management.

Keywords: higher education teachers, ICT, stress, technoeustress

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Authors: Gabi N. Nehme, Saeed Ghalambor

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The use of titanium fluoride and iron fluoride (TiF3/FeF3) catalysts in combination with polutetrafluoroethylene (PTFE) in plain zinc dialkyldithiophosphate (ZDDP) oil is important for the study of engine tribocomponents and is increasingly a strategy to improve the formation of tribofilm and to provide low friction and excellent wear protection in reduced phosphorus plain ZDDP oil. The influence of surface roughness and the concentration of TiF3/FeF3/PTFE were investigated using bearing steel samples dipped in lubricant solution @100°C for two different heating time durations. This paper addresses the effects of water drop contact angle using different surface finishes after treating them with different lubricant combination. The calculated water drop contact angles were analyzed using Design of Experiment software (DOE) and it was determined that a 0.05 μm Ra surface roughness would provide an excellent TiF3/FeF3/PTFE coating for antiwear resistance as reflected in the scanning electron microscopy (SEM) images and the tribological testing under extreme pressure conditions. Both friction and wear performance depend greatly on the PTFE/and catalysts in plain ZDDP oil with 0.05% phosphorous and on the surface finish of bearing steel. The friction and wear reducing effects, which was observed in the tribological tests, indicated a better micro lubrication effect of the 0.05 μm Ra surface roughness treated at 100°C for 24 hours when compared to the 0.1 μm Ra surface roughness with the same treatment.

Keywords: scanning electron microscopy, ZDDP, catalysts, PTFE, friction, wear

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Authors: Priscila Vitorino, Jeeziane Rezende, Edison Pereira, Adrielly Silva, Weimar Barroso

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Body composition insight during physical activity is relevant to follow up sports income since it can be important and actuate in velocity, resistance, potency, and has an effect on force and agility. The purpose of this study was to identify anthropometric profile, evaluate and correlate body mass index and bioimpedance behavior during the days of Caminhada Ecológica de Goiás - Brasil. A longitudinal study was performed with 25 male participants, with an average age of 45.6±9.1 years. All patients were actives. Body composition was evaluated by body mass index (BMI) measurement and bioimpedance procedures. Both were collected 20 days before walking beginning (A0) and in the four days along the same (A1, A2, A3 e A4). Data were collected in the end of each walking day at athletes accommodations. Final distance during walking route was 308 km in five days, with an average of 62km/day and 7,6 km/hour, and an average temperature of 30°C. Data are represented with mean and standard deviation. ANOVA (Bonferroni pos test) was used to compare frequent measurements between the days. Pearson's correlation test was used to correlate BMI with lean mass, fat mass, and water. BMI decreased from A0 to A1, A2 and A3 (p < 0,01) and increased on A4 (p < 0,01). No changes were observed concerning fat percentage (p=0,60), lean mass (p=0,10) and body water composition (p=0,09). A positive and moderate correlation between BMI and fat percentage was observed; an inverse and moderate correlation between BMI, lean mass and body water composition occurred. Total body mass increased during high intensity and long term walking distance. However, the values of body fat, lean mass and water were maintained.

Keywords: aerobic exercise, body composition, metabolism, sports

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Authors: Iyd Eqqab Maree, Habil Jurgen Bast

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Vibration control of machines and structures incorporating viscoelastic materials in suitable arrangement is an important aspect of investigation. The use of viscoelastic layers constrained between elastic layers is known to be effective for damping of flexural vibrations of structures over a wide range of frequencies. The energy dissipated in these arrangements is due to shear deformation in the viscoelastic layers, which occurs due to flexural vibration of the structures. Multilayered cantilever sandwich beam like structures can be used in aircrafts and other applications such as robot arms for effective vibration control. These members may experience parametric instability when subjected to time dependant forces. The theory of dynamic stability of elastic systems deals with the study of vibrations induced by pulsating loads that are parametric with respect to certain forms of deformation. The purpose of the present work is to investigate the dynamic stability of a three layered symmetric sandwich beam (Drone Aircraft wings ) subjected to an end periodic axial force . Equations of motion are derived using finite element method (MATLAB software). It is observed that with increase in core thickness parameter fundamental buckling load increases. The fundamental resonant frequency and second mode frequency parameter also increase with increase in core thickness parameter. Fundamental loss factor and second mode loss factor also increase with increase in core thickness parameter. Increase in core thickness parameter enhances the stability of the beam. With increase in core loss factor also the stability of the beam enhances. There is a very good agreement of the experimental results with the theoretical findings.

Keywords: steel cantilever beam, viscoelastic material core, loss factor, transition region, MATLAB R2011a

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Authors: Jiechen Yin, Xiang Hong, Ran Liu

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Atrazine (ATR), a widely used triazine herbicide, is an environmental endocrine disruptor that can cause health problems. However, whether there are multi/trans-generational reproductive impacts of ATR have not been studied to our best knowledge. Therefore, in this study, Caenorhabditis elegans was used as a preferable model organism to identify the multi/trans-generational reproductive toxicity of ATR. L1 larvae were exposed to different concentrations (0.0004–40 mg/L) of ATR for 48 h. Successive generations (F1 to F5) were fed without ATR and consecutive exposure. The results showed that ATR exposure during P0 decreased fecundity, including a reduction in fertilized eggs, oocytes, and ovulation rate, delayed gonadal development, and decreased the relative area of the gonad arm and germ cell number. Furthermore, continuous ATR exposure (P0–F5) causes a significant increase in reproductive toxicity in subsequent generations, although no significant toxicity occurred in the P0 generation after exposure to environmental-related concentrations, suggesting that ATR exposure might have cumulative effects. Likewise, parental exposure to ATR caused transgenerational toxicity impairments. Interestingly, reproductive toxicity not development toxicity was transmitted to several generations (F1–F4), and the F2 generation showed the most notable changes. QRT-PCR results showed that genes related to DNA methylation 6mA (damt-1, nmad-1) and histone H3 methylation (mes-4, met-2, set-25, set-2, and utx-1) can also be passed on to offspring. The function of H3K4 and H3K9 methylation were explored by using loss-of-function mutants for set-2, set-25, and met-2. Transmissible reproductive toxicity was absent in met-2(n4256), set-2(ok952), and set-25(n5021) mutants, which suggests that the histone methyltransferases H3K4 and H3K9 activity are indispensable for the transgenerational effect of ATR. Finally, the downstream genes of DNA methylation and histone H3 methylation were determined. ATR upregulated the expression of ZC317.7, hsp-6, and hsp-60. Mitochondrial stress in parental generation dependent transcription 6mA modifiers may establish these epigenetic marks in progeny.

Keywords: ATR, Caenorhabditis elegans, multi-/trans-generation, reproductive toxicity

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Authors: Micheale Yifter Weldemichael

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Sesame (Sesamum indicum L.) is among the most important oilseed crops for its high edible oil quality and quantity. Sesame is grown for food, medicinal, pharmaceutical, and industrial uses. Sesame is also cultivated as a main cash crop in Asia and Africa by smallholder farmers. Despite the global exponential increase in sesame cultivation area, its production and productivity remain low, mainly due to biotic and abiotic constraints. Notwithstanding the efforts to solve these problems, a low level of genetic variation and inadequate genomic resources hinder the progress of sesame improvement. The objective of this paper is, therefore, to review recent advances in the area of molecular breeding and transformation to overcome major production constraints and could result in enhanced and sustained sesame production. This paper reviews various researches conducted to date on molecular breeding and genetic transformation in sesame focusing on molecular markers used in assessing the available online database resources, genes responsible for key agronomic traits as well as transgenic technology and genome editing. The review concentrates on quantitative and semi-quantitative studies on molecular breeding for key agronomic traits such as improvement of yield components, oil and oil-related traits, disease and insect/pest resistance, and drought, waterlogging and salt tolerance, as well as sesame genetic transformation and genome editing techniques. Pitfalls and limitations of existing studies and methodologies used so far are identified and some priorities for future research directions in sesame genetic improvement are identified in this review.

Keywords: abiotic stress, biotic stress, improvement, molecular breeding, oil, sesame, shattering

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Authors: Renata De Toledo Cintra, Bruno Ramos, Douglas Gouvêa

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There is a huge global concern due to the emission of greenhouse gases, consequent environmental problems, and the increase in the average temperature of the planet, caused mainly by fossil fuels, petroleum derivatives represent a big part. One of the main greenhouse gases, in terms of volume, is CO₂. Recovering a part of this product through chemical reactions that use sunlight as an energy source and even producing renewable fuel (such as ethane, methane, ethanol, among others) is a great opportunity. The process of artificial photosynthesis, through the conversion of CO₂ and H₂O into organic products and oxygen using a metallic oxide catalyst, and incidence of sunlight, is one of the promising solutions. Therefore, this research is of great relevance. To this reaction take place efficiently, an optimized reactor was developed through simulation and prior analysis so that the geometry of the internal channel is an efficient route and allows the reaction to happen, in a controlled and optimized way, in flow continuously and offering the least possible resistance. The design of this reactor prototype can be made in different materials, such as polymers, ceramics and metals, and made through different processes, such as additive manufacturing (3D printer), CNC, among others. To carry out the photocatalysis in the reactors, different types of catalysts will be used, such as ZnO deposited by spray pyrolysis in the lighting window, probably modified ZnO, TiO₂ and modified TiO₂, among others, aiming to increase the production of organic molecules, with the lowest possible energy.

Keywords: artificial photosynthesis, CO₂ reduction, photocatalysis, photoreactor design, 3D printed reactors, solar fuels

Procedia PDF Downloads 84

Authors: Mohammed A. Al-Yafrsi, Fahed A. Al-Mana

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A study was conducted to evaluate the compaction-tolerance ability of some warm season turfgrasses under shade and sunlight conditions in Riyadh, Saudi Arabia. Hybrid bermudagrass (Cynodon dactylon): 'Tifway' and 'Tifsport', seashore paspalum (Paspalum vaginatum) and its cultivar 'Sea Isle 2000' were used. The study area was divided into two sections where one was exposed to sunlight and the other one was maintained under shade using green plastic grille (shade 70%). Turfgrasses were planted by sods in beds containing a mixture of sand, silt, and peat moss (4: 1: 1, v/v). The soil compaction was applied using a locally-made cylindrical roll (weighing 250 kg), passing four times over the growing turfgrasses for 3 days/week. The results revealed that compaction treatment led to a decrease in grass height, and it was the lowest (4.0 cm) for paspalum 'Sea Isle 2000' in February. At the shaded area, paspalum turfgrasses retained its high quality degree (4.0) in April, May, and June. In the sunlight area, the grass quality degree was the greatest (4.0) in 'Sea Isle 2000' and the lowest (3.0) in 'Tifsport'. Paspalum turfgrasses gave higher color degree (4) than bermuda grasses (2.5) in April, May, and June. The compaction also led to a decline in leaf area, fresh and dry weights of all grown turfgrasses. The grass density was high for paspalum turfgrasses indicating that their resistance to compaction was greater than bermudagrasses. It can be concluded that the best compaction and shade tolerant turfgrasses are 'Sea Isle 2000' and seashore paspalum.

Keywords: hybrid bermudagrass, seashore paspalum, soil compaction, shade area, sunlight condition

Procedia PDF Downloads 118

Authors: Satya Eswari Jujjavarapu, Swast Dhagat

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Contagious diseases enact severe public health problems and have upsetting consequences. The cyclic lipopeptides explained by bacteria Bacillus, Paenibacillus, Pseudomonas, Streptomyces, Serratia, Propionibacterium and fungus Fusarium are very critical in confining the pathogens. As the degree of drug resistance upsurges in unparalleled manner, the perseverance of searching novel cyclic lipopeptides is being professed. The intense study has shown the implication of these bioactive compounds extending beyond antibacterial and antifungal. Lipopeptides, composed of single units of peptide and fatty acyl moiety, show broad spectrum antimicrobial effects. Among the surplus of cyclic lipopeptides, only few have materialized as strong antibiotics. For their functional vigor, polymyxin, daptomycin, surfactin, iturin and bacillomycin have been integrated in mainstream healthcare. In our work daptomycin has been a major part of antimicrobial resource since the past decade. Daptomycin, a cyclic lipopeptide consists of 13-member amino acid with a decanoyl side-chain. This structure of daptomycin confers it the mechanism of action through which it forms pore in the bacterial cell membrane resulting in the death of cell. Daptomycin is produced by Streptococccus roseoporus and acts against Streptococcus pneumonia (PSRP), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The PDB structure and ligands of daptomycin are available online. The molecular docking studies of these ligands with the lipopeptides were performed and their docking score and glide energy were recorded.

Keywords: daptomycin, molecular docking, structure-based drug design, lipopeptide

Procedia PDF Downloads 264

Authors: H. Lahlali F. El Haouzi, A.M.Al-Baradi, I. El Aboudi, M. El Azhari, A. Mdarhri

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Polytetrafluoroethylene (PTFE) is a high performance thermoplastic polymer with exceptional physical and chemical properties, such as a high melting temperature, high thermal stability, and very good chemical resistance. Nevertheless, manufacturing PTFE is problematic due to its high melt viscosity (10 12 Pa.s). In practice, it is by now well established that this property presents a serious problem when the classical methods are used to synthesized the dense PTFE materials in particularly hot pressing, high temperature extrusion. In this framework, we use here a new process namely spark plasma sintering (SPS) to elaborate PTFE samples from the micro metric particles powder. It consists in applying simultaneous electric current and pressure directly on the sample powder. By controlling the processing parameters of this technique, a series of PTFE samples are easy obtained and associated to remarkably short time as is reported in an early work. Our central goal in the present study is to understand how the non conventional SPS affects the mechanical properties at room temperature. For this end, a second commercially series of PTFE synthesized by using the extrusion method is investigated. The first data according to the tensile mechanical properties are found to be superior for the first set samples (SPS). However, this trend is not observed for the results obtained from the compression testing. The observed macro-behaviors are correlated to some physical properties of the two series of samples such as their crystallinity or density. Upon a close examination of these properties, we believe the SPS technique can be seen as a promising way to elaborate the polymer having high molecular mass without compromising their mechanical properties.

Keywords: PTFE, extrusion, Spark Plasma Sintering, physical properties, mechanical behavior

Procedia PDF Downloads 306

Authors: Jyotsna Gupta, S. Ghosh, S. Aravindan

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The requirement of artificial prostheses (such as hip and knee joints) has increased with time. Many researchers are working to develop new implants with improved properties such as excellent biocompatibility with no tissue reactions, corrosion resistance in body fluid, high yield strength and low elastic modulus. Further, the morphological properties of the artificial implants should also match with that of the human bone so that cell adhesion, proliferation and transportation of the minerals and nutrition through body fluid can be obtained. Present study attempts to make porous Ti6Al15Mo alloys through powder metallurgy route using space holder technique. The alloy consists of 6wt% of Al which was taken as α phase stabilizer and 15wt% Mo was taken as β phase stabilizer with theoretical density 4.708. Ammonium hydrogen carbonate is used as a space holder in order to generate the porosity. The porosity of these fabricated porous alloys was controlled by adding the 0, 50, 70 vol.% of the space holder content. Three phases were found in the microstructure: α, α_2 and β phase of titanium. Kirkendall pores are observed to be decreased with increase of holding time during sintering and parallelly compressive strength and elastic modulus value increased slightly. Compressive strength and elastic modulus of porous Ti-6Al-15Mo alloy (1.17 g/cm3 density) is found to be suitable for cancellous bone. Released ions from Ti-6Al-15Mo alloy are far below from the permissible limits in human body.

Keywords: bone implant, powder metallurgy, sintering time, Ti-6Al-15Mo

Procedia PDF Downloads 143

Authors: Saylav Ejder Bora, Arife Erdogan, Mumin Alper Erdogan, Oytun Erbas, Ismet Parlak

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Objective: The aim of this study was to evaluate histological, electrical and biochemical effects of metoprolol, lipid emulsion and magnesium sulphate as an alternative method to be used in preventing long QT emergence, that is among the lethal consequences of amitryptiline toxicity. Methods: Thirty Sprague- Dawley male rats were included. Rats were randomly separated into 5 groups. First group was administered saline only while the rest had received amitryptiline 100 mg/kg + saline, 5 mg/kg metoprolol, 20 ml/kg lipid emulsion and 75 mg/kg magnesium sulphate (MgSO4) intraperitoneally. ECG at DI lead, biochemical tests following euthanasia were performed in all groups after 1 hour of administration. Cardiac tissues were removed, sections were prepared and examined. Results: QTc values were significantly shorter in the rest when compared to amitryptiline+ saline group. While lipid emulsion did not affect proBNP and troponin values biochemically as compared to that of the control group, histologically, it was with reduced caspase 3 expression. Though statistically insignificant in the context of biochemical changes, pro-BNP and urea levels were lower in the metoprolol group when compared to controls. Similarly, metoprolol had no statistically significant effect on histological caspase 3 expression in the group that was treated with amitryptiline+metoprolol. On the other hand, there was a statistically significant decrease in Troponin, pro-BNP and urea levels as well as significant decline in histological caspase 3 expression within the MgSO4 group when compared to controls. Conclusion: As still a frequent cause of mortality in emergency units, administration of MgSO4, lipid emulsion and metoprolol might be beneficial in alternative treatment of cardiovascular toxicity caused by tricyclic antidepressant overdose, whether intake would be intentional or accidental.

Keywords: amitryptiline, cardiovascular toxicity, long QT, Rat Model

Procedia PDF Downloads 175

Authors: H. M. D. Prabhashana Herath, M. D. Anuradha Wickramasinghe, A. M. C. Kalpani Polgolla, R. A. C. Prasad Ranasinghe, M. Anusha Wijewardane

Abstract:

The demand for thermal comfort in buildings in hot and humid climates increases progressively. In general, buildings in hot and humid climates spend more than 60% of the total energy cost for the functionality of the air conditioning (AC) system. Hence, it is required to install energy efficient AC systems or integrate energy recovery systems for both new and/or existing AC systems whenever possible, to reduce the energy consumption by the AC system. Integrate a Rotary Thermal Wheel as the energy recovery device of an existing AC system has shown very promising with attractive payback periods of less than 5 years. A rotary thermal wheel can be located in the Air Handling Unit (AHU) of a central AC system to recover the energy available in the return air stream. During this study, a sensitivity analysis was performed using a CFD (Computational Fluid Dynamics) software to determine the optimum design parameters (i.e., rotary speed and parameters of the matrix profile) of a rotary thermal wheel for hot and humid climates. The simulations were performed for a sinusoidal matrix geometry. Variation of sinusoidal matrix parameters, i.e., span length and height, were also analyzed to understand the heat exchanging performance and the induced pressure drop due to the air flow. The results show that the heat exchanging performance increases when increasing the wheel rpm. However, the performance increment rate decreases when increasing the rpm. As a result, it is more advisable to operate the wheel at 10-20 rpm. For the geometry, it was found that the sinusoidal geometries with lesser spans and higher heights have higher heat exchanging capabilities. Considering the sinusoidal profiles analyzed during the study, the geometry with 4mm height and 3mm width shows better performance than the other combinations.

Keywords: air conditioning, computational fluid dynamics, CFD, energy recovery, heat exchangers

Procedia PDF Downloads 127

Authors: Omran M. Kenshel, Alan J. O'Connor

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Estimating the service life of Reinforced Concrete (RC) bridge structures located in corrosive marine environments of a great importance to their owners/engineers. Traditionally, bridge owners/engineers relied more on subjective engineering judgment, e.g. visual inspection, in their estimation approach. However, because financial resources are often limited, rational calculation methods of estimation are needed to aid in making reliable and more accurate predictions for the service life of RC structures. This is in order to direct funds to bridges found to be the most critical. Criticality of the structure can be considered either form the Structural Capacity (i.e. Ultimate Limit State) or from Serviceability viewpoint whichever is adopted. This paper considers the service life of the structure only from the Structural Capacity viewpoint. Considering the great variability associated with the parameters involved in the estimation process, the probabilistic approach is most suited. The probabilistic modelling adopted here used Monte Carlo simulation technique to estimate the Reliability (i.e. Probability of Failure) of the structure under consideration. In this paper the authors used their own experimental data for the Correlation Length (CL) for the most important deterioration parameters. The CL is a parameter of the Correlation Function (CF) by which the spatial fluctuation of a certain deterioration parameter is described. The CL data used here were produced by analyzing 45 chloride profiles obtained from a 30 years old RC bridge located in a marine environment. The service life of the structure were predicted in terms of the load carrying capacity of an RC bridge beam girder. The analysis showed that the influence of SV is only evident if the reliability of the structure is governed by the Flexure failure rather than by the Shear failure.

Keywords: Chloride-induced corrosion, Monte-Carlo simulation, reinforced concrete, spatial variability

Procedia PDF Downloads 472