Search results for: optimized criteria
1189 Preventive Interventions for Central Venous Catheter Infections in Intensive Care Units: A Systematic Literature Review
Authors: Jakob Renko, Deja Praprotnik, Kristina Martinovič, Igor Karnjuš
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Introduction: Catheter-related bloodstream infections are a major burden for healthcare and patients. Although infections of this type cannot be completely avoided, they can be reduced by taking preventive measures. The aim of this study is to review and analyze the existing literature on preventive interventions to prevent central venous catheters (CVC) infections. Methods: A systematic literature review was carried out. The international databases CINAHL, Medline, PubMed, and Web of Science were searched using the search strategy: "catheter-related infections" AND "intensive care units" AND "prevention" AND "central venous catheter." Articles that met the inclusion and exclusion criteria were included in the study. The literature search flow is illustrated by the PRISMA diagram. The descriptive research method was used to analyze the data. Results: Out of 554 search results, 22 surveys were included in the final analysis. We identified seven relevant preventive measures to prevent CVC infections: washing the whole body with chlorhexidine gluconate (CHG) solution, disinfecting the CVC entry site with CHG solution, use of CHG or silver dressings, alcohol protective caps, CVC care education, selecting appropriate catheter and multicomponent care bundles. Discussion and conclusions: Both single interventions and multicomponent care bundles have been shown to be currently effective measures to prevent CVC infections in adult patients in the ICU. None of the measures identified stood out in terms of their effectiveness. Prevention work to reduce CVC infections in the ICU is a complex process that requires the simultaneous consideration of several factors.Keywords: central venous access, critically ill patients, hospital-acquired complications, prevention
Procedia PDF Downloads 3361188 Cleaning of Polycyclic Aromatic Hydrocarbons (PAH) Obtained from Ferroalloys Plant
Authors: Stefan Andersson, Balram Panjwani, Bernd Wittgens, Jan Erik Olsen
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Polycyclic Aromatic hydrocarbons are organic compounds consisting of only hydrogen and carbon aromatic rings. PAH are neutral, non-polar molecules that are produced due to incomplete combustion of organic matter. These compounds are carcinogenic and interact with biological nucleophiles to inhibit the normal metabolic functions of the cells. Norways, the most important sources of PAH pollution is considered to be aluminum plants, the metallurgical industry, offshore oil activity, transport, and wood burning. Stricter governmental regulations regarding emissions to the outer and internal environment combined with increased awareness of the potential health effects have motivated Norwegian metal industries to increase their efforts to reduce emissions considerably. One of the objective of the ongoing industry and Norwegian research council supported "SCORE" project is to reduce potential PAH emissions from an off gas stream of a ferroalloy furnace through controlled combustion. In a dedicated combustion chamber. The sizing and configuration of the combustion chamber depends on the combined properties of the bulk gas stream and the properties of the PAH itself. In order to achieve efficient and complete combustion the residence time and minimum temperature need to be optimized. For this design approach reliable kinetic data of the individual PAH-species and/or groups thereof are necessary. However, kinetic data on the combustion of PAH are difficult to obtain and there is only a limited number of studies. The paper presents an evaluation of the kinetic data for some of the PAH obtained from literature. In the present study, the oxidation is modelled for pure PAH and also for PAH mixed with process gas. Using a perfectly stirred reactor modelling approach the oxidation is modelled including advanced reaction kinetics to study influence of residence time and temperature on the conversion of PAH to CO2 and water. A Chemical Reactor Network (CRN) approach is developed to understand the oxidation of PAH inside the combustion chamber. Chemical reactor network modeling has been found to be a valuable tool in the evaluation of oxidation behavior of PAH under various conditions.Keywords: PAH, PSR, energy recovery, ferro alloy furnace
Procedia PDF Downloads 2731187 Towards Improved Public Information on Industrial Emissions in Italy: Concepts and Specific Issues Associated to the Italian Experience in IPPC Permit Licensing
Authors: C. Mazziotti Gomez de Teran, D. Fiore, B. Cola, A. Fardelli
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The present paper summarizes the analysis of the request for consultation of information and data on industrial emissions made publicly available on the web site of the Ministry of Environment, Land and Sea on integrated pollution prevention and control from large industrial installations, the so called “AIA Portal”. However, since also local Competent Authorities have been organizing their own web sites on IPPC permits releasing procedures for public consultation purposes, as a result, a huge amount of information on national industrial plants is already available on internet, although it is usually proposed as textual documentation or images. Thus, it is not possible to access all the relevant information through interoperability systems and also to retrieval relevant information for decision making purposes as well as rising of awareness on environmental issue. Moreover, since in Italy the number of institutional and private subjects involved in the management of the public information on industrial emissions is substantial, the access to the information is provided on internet web sites according to different criteria; thus, at present it is not structurally homogeneous and comparable. To overcome the mentioned difficulties in the case of the Coordinating Committee for the implementation of the Agreement for the industrial area in Taranto and Statte, operating before the IPPC permit granting procedures of the relevant installation located in the area, a big effort was devoted to elaborate and to validate data and information on characterization of soil, ground water aquifer and coastal sea at disposal of different subjects to derive a global perspective for decision making purposes. Thus, the present paper also focuses on main outcomes matured during such experience.Keywords: public information, emissions into atmosphere, IPPC permits, territorial information systems
Procedia PDF Downloads 2851186 Emergence of Vancomycin Resistant and Methcillin Resistant Staphylococus aureus in Patients with Different Clinical Manifestations in Khartoum State, Sudan
Authors: Maimona A. E. Elimam, Suhair Rehan, Miskelyemen A. Elmekki, Mogahid M. Elhassan
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Staphylococcus aureus (Staph. aureus), a major cause of potentially life-threatening infections acquired in healthcare and community settings, has developed resistance to most classes of antimicrobial agents as determined by the dramatic increase. The present study aimed to determine the prevalence of MRSA, and VRSA in patients with different clinical manifestations in Khartoum state. The study population (n, 426) were males and females with different age categories, suffering either from wound infections (105), ear infections (121), or UTI (101), in addition to nasal carriers of medical staff (100). Cultures, Gram staining, and other biochemical tests were performed for conventional identification. Modified Kirby-Bauer disk diffusion method was applied and DNA was extracted from MRSA and VRSA isolates and PCR was then performed for amplification of arc, mecA, VanA, and VanB genes. The results confirmed the existence of Staph. aureus in 49/426 (11.5%) cases among which MRSA were isolated from 34/49 (69.4%) when modified Kirby-Bauer disk diffusion method was applied. Ten out of these 34 MRSA were confirmed as VRSA by cultures on BHI agar containing 6μg/ml vancomycin according to NCCLS criteria. PCR revealed that out of the 34 MRSA isolates, 26 were mecA positive (76.5%) while 8 (23.5%) were arcC positive. No vanA or VanB genes were detected. Molecular method confirmed the results for MRSA through the presence of either arcC or mecA genes while it failed to approve the occurrence of VRSA since neither VanA or VanB genes were detected. Thus, VRSA may be attributed to other factors.Keywords: antibiotic resistance, Staphylococcus aureus, VRSA, MRSA, Khartoum, Sudan
Procedia PDF Downloads 4341185 Latinx Adult ELLs: Exploring English Instructors’ Perceptions of Classroom Diversity and Culturally Diverse Teaching Strategies
Authors: Sharon Diaz Ruiz
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This qualitative study addresses college English instructors’ perceptions of classroom diversity and culturally diverse teaching strategies within the adult English language learning classroom environment. Every year, English college instructors face numerous challenges as the adult Latinx population keeps rising. To better understand the Latinx adult learners and the language classroom dynamics, research should focus on the experiences, pedagogical methods, and teaching insights of full-time and adjunct minority professors at degree-granting postsecondary institutions. Culturally responsive teaching is used as the framework to understand and explore the perceptions of English instructors on the realities and needs of Latinx adult emergent bilinguals enrolled in developmental English courses. Snowball sampling allows the researcher to locate members who meet these specific criteria: adjunct and part-time English instructors of adult Latinx language learners. Participants answered a demographic questionnaire and then contributed to 45-minute in-depth interviews to explore their perceptions of culturally responsive practices in the Latinx adult emergent bilinguals’ basic and intermediate developmental English courses. The interviews shed light on topics such as teaching biases, educators’ cultural experiences, and resources and strategies faculty recommend for effective culturally responsive teaching strategies. The result of this investigation will shed light on the gap in the literature documenting the application of culturally responsive pedagogy to Latino adult language learners.Keywords: Latinx, English language learners, English faculty, adult learners, critical theory, culturally responsive theory
Procedia PDF Downloads 671184 An Evaluation of Education Provision for Students with Autism Spectrum Disorder in Ireland: The Role of the Special Needs Assistant
Authors: Claire P. Griffin
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The education provision for students with special educational needs, including students with Autism Spectrum Disorder (ASD), has undergone significant national and international changes in recent years. In particular, an increase in resource-based provision has occurred across educational settings in an effort to support inclusive practices. This paper seeks to explore the role of the Special Needs Assistant (SNA) in supporting children with ASD in Irish schools. This research stems from the second national evaluation of ‘Education Provision for Students with Autism Spectrum Disorder in Ireland’ (NCSE, 2016). This research was commissioned by the National Council for Special Education (NCSE) in Ireland and conducted by a team of researchers from Mary Immaculate College, Limerick from February to July 2014. This study involved a multiple case study research strategy across 24 educational sites, as selected through a stratified sampling process. Research strategies included semi-structured interviews, classroom observations, documentary review and child conversations. Data analysis was conducted electronically using Nvivo software, with use of an additional quantitative recording mechanism based on scaled weighting criteria for collected data. Based on such information, key findings from the NCSE national evaluation will be presented and critically reviewed, with particular reference to the role of the SNA in supporting pupils with ASD. Examples of positive practice inherent within the SNA role will be outlined and contrasted with discrete areas for development. Based on such findings, recommendations for the evolving role of the SNA will be presented, with the aim of informing both policy and best practice within the field.Keywords: autism spectrum disorder, inclusive education , paraprofessional, special needs assistant
Procedia PDF Downloads 2791183 Assessment of Health Literacy and Awareness of Female Residents of Barangay Dagatan, Sabang, and Marauoy Lipa, Batangas on Polycystic Ovarian Syndrome: A Cross-Sectional Study
Authors: Jean Gray C. Achapero, Mary Margareth P. Ancheta, Patricia Anjelika A. Angeles, Shannon Denzel S. Ao Tai, Carl Brandon C. Barlis, Chrislen Mae B. Benavidez
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Health literacy and awareness of Polycystic ovarian syndrome (PCOS) is a global issue that is under-addressed in the Philippines. Conducting a thorough review of the country's ability to recognize and comprehend the severity of the syndrome should be undertaken, as early treatment is essential to avoid further disorder complications. This research aims to assess the health literacy and awareness of the female residents of Barangay Dagatan, Sabang, and Marauoy Lipa, Batangas on PCOS. It followed a cross-sectional study, and data gathering was done through a pre-assessment using the Single Item Literacy Screener (SILS) and an online population-based survey questionnaire about PCOS awareness. The participants, as based on the objectives and purposive sampling method, were females aged 18-45 years old. Data were analyzed statistically using STATA 13.1 software. The study showed that 339 (76%) out of 444 respondents passed the SILS meaning the residents have proficient health literacy. Among the 339 respondents, 87% (287) had previous knowledge about PCOS. The respondents showed minimal awareness of PCOS symptoms which could be attributed to its broad spectrum of information. Respondents were shown to be most knowledgeable about PCOS physiology, treatment, beliefs, and its remedies. The respondents’ age had no significant association with their health literacy (p=0.31) and PCOS awareness (p=0.60). A significant association was noted, however, in their educational attainment linked with their health literacy (p=<0.0001) and PCOS awareness (p=0.001). It is suggested that reproductive health education even in the lower year levels must be optimized and Local Government Unit (LGU)/Non-Government Organization (NGO)-held seminars should be conducted for knowledge reinforcement. Reliable health information should be more accessible to the public and clinicians must emphasize the importance of the majority of early screening as part of routine physical examination for women of reproductive age to increase health literacy and awareness about PCOS and actively engage in the management of the disease.Keywords: age, awareness, educational attainment, health literacy, polycystic ovarian syndrome
Procedia PDF Downloads 2281182 A Rapid Prototyping Tool for Suspended Biofilm Growth Media
Authors: Erifyli Tsagkari, Stephanie Connelly, Zhaowei Liu, Andrew McBride, William Sloan
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Biofilms play an essential role in treating water in biofiltration systems. The biofilm morphology and function are inextricably linked to the hydrodynamics of flow through a filter, and yet engineers rarely explicitly engineer this interaction. We develop a system that links computer simulation and 3-D printing to optimize and rapidly prototype filter media to optimize biofilm function with the hypothesis that biofilm function is intimately linked to the flow passing through the filter. A computational model that numerically solves the incompressible time-dependent Navier Stokes equations coupled to a model for biofilm growth and function is developed. The model is imbedded in an optimization algorithm that allows the model domain to adapt until criteria on biofilm functioning are met. This is applied to optimize the shape of filter media in a simple flow channel to promote biofilm formation. The computer code links directly to a 3-D printer, and this allows us to prototype the design rapidly. Its validity is tested in flow visualization experiments and by microscopy. As proof of concept, the code was constrained to explore a small range of potential filter media, where the medium acts as an obstacle in the flow that sheds a von Karman vortex street that was found to enhance the deposition of bacteria on surfaces downstream. The flow visualization and microscopy in the 3-D printed realization of the flow channel validated the predictions of the model and hence its potential as a design tool. Overall, it is shown that the combination of our computational model and the 3-D printing can be effectively used as a design tool to prototype filter media to optimize biofilm formation.Keywords: biofilm, biofilter, computational model, von karman vortices, 3-D printing.
Procedia PDF Downloads 1421181 Improving Self-Administered Medication Adherence for Older Adults: A Systematic Review
Authors: Mathumalar Loganathan, Lina Syazana, Bryony Dean Franklin
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Background: The therapeutic benefit of self-administered medication for long-term use is limited by an average 50% non-adherence rate. Patient forgetfulness is a common factor in unintentional non-adherence. With a growing ageing population, strategies to improve self-administration of medication adherence are essential. Our aim was to review systematically the effects of interventions to optimise self-administration of medication. Method: Database searched were MEDLINE, EMBASE, PsynINFO, CINAHL from 1980 to 31 October 2013. Search terms included were ‘self-administration’, ‘self-care’, ‘medication adherence’, and ‘intervention’. Two independent reviewers undertook screening and methodological quality assessment, using the Downs and Black rating scale. Results: The search strategy retrieved 6 studies that met the inclusion and exclusion criteria. Three intervention strategies were identified: self-administration medication programme (SAMP), nursing education and medication packaging (pill calendar). A nursing education programme focused on improving patients’ behavioural self-management of drug prescribing. This was the most studied area and three studies highlighting an improvement in self-administration of medication. Conclusion: Results are mixed and there is no one interventional strategy that has proved to be effective. Nevertheless, self-administration of medication programme seems to show most promise. A multi-faceted approach and clearer policy guideline are likely to be required to improve prescribing for these vulnerable patients. Mixed results were found for SAMP. Medication packaging (pill calendar) was evaluated in one study showing a significant improvement in self-administration of medication. A meta-analysis could not be performed due to heterogeneity in the outcome measures.Keywords: self-administered medication, intervention, prescribing, older patients
Procedia PDF Downloads 3231180 Comparative Study to Evaluate the Efficacy of Control Criterion in Determining Consolidation Scope in the Public Sector
Authors: Batool Zarei
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This study aims to answer this question whether control criterion with two elements of power and benefit which is introduced as 'control criterion of consolidation scope' in national and international standards of accounting in public sector (and also private sector) is efficient enough or not. The methodology of this study is comparative and the results of this research are significantly generalizable, due to the given importance to the sample of countries which were studied. Findings of this study states that in spite of pervasive use of control criterion (including 2 elements of power and benefit), criteria for determining the existence of control in public sector accounting standards, are not efficient enough to determine the consolidation scope of whole of government financial statements in a way that meet decision making and accountability needs of managers, policy makers and supervisors; specially parliament. Therefore, the researcher believes that for determining consolidation scope in public sector, in addition to economic view, it is better to pay attention to budgetary, legal and statistical concepts and also to practical and financial risk and define indicators for proving the existence of control (power and benefit) which include accountability relationships (budgetary relation, legal form and nature of activity). these findings also reveals the necessity of passing a comprehensive public financial management (PFM) legislation in order to redefine the characteristics of public sector entities and whole of government financial statements scope and review Statistics organizations and central banks duties for preparing government financial statistics and national accounts in order to achieve sustainable development and resilient economy goals.Keywords: control, consolidation scope, public sector accounting, government financial statistics, resilient economy
Procedia PDF Downloads 2581179 Mindfulness and Mental Resilience Training for Pilots: Enhancing Cognitive Performance and Stress Management
Authors: Nargiza Nuralieva
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The study delves into assessing the influence of mindfulness and mental resilience training on the cognitive performance and stress management of pilots. Employing a meticulous literature search across databases such as Medline and Google Scholar, the study used specific keywords to target a wide array of studies. Inclusion criteria were stringent, focusing on peer-reviewed studies in English that utilized designs like randomized controlled trials, with a specific interest in interventions related to mindfulness or mental resilience training for pilots and measured outcomes pertaining to cognitive performance and stress management. The initial literature search identified a pool of 123 articles, with subsequent screening resulting in the exclusion of 77 based on title and abstract. The remaining 54 articles underwent a more rigorous full-text screening, leading to the exclusion of 41. Additionally, five studies were selected from the World Health Organization's clinical trials database. A total of 11 articles from meta-analyses were retained for examination, underscoring the study's dedication to a meticulous and robust inclusion process. The interventions varied widely, incorporating mixed approaches, Cognitive behavioral Therapy (CBT)-based, and mindfulness-based techniques. The analysis uncovered positive effects across these interventions. Specifically, mixed interventions demonstrated a Standardized Mean Difference (SMD) of 0.54, CBT-based interventions showed an SMD of 0.29, and mindfulness-based interventions exhibited an SMD of 0.43. Long-term effects at a 6-month follow-up suggested sustained impacts for both mindfulness-based (SMD: 0.63) and CBT-based interventions (SMD: 0.73), albeit with notable heterogeneity.Keywords: mindfulness, mental resilience, pilots, cognitive performance, stress management
Procedia PDF Downloads 551178 Knowledge of Quality Assurance and Quality Control in Mammography; A Study among Radiographers of Mammography Settings in Sri Lanka
Authors: H. S. Niroshani, W. M. Ediri Arachchi, R. Tudugala, U. J. M. A. L. Jayasinghe, U. M. U. J. Jayasekara, P. B. Hewavithana
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Mammography is used as a screening tool for early diagnosis of breast cancer. It is also useful in refining the diagnosis of breast cancer either by assessment or work up after a suspicious area in the breast has been detected. In order to detect breast cancer accurately and at the earliest possible stage, the image must have an optimum contrast to reveal mass densities and spiculated fibrous structures radiating from them. In addition, the spatial resolution must be adequate to reveal the suffusion of micro calcifications and their shape. The above factors can be optimized by implementing an effective QA programme to enhance the accurate diagnosis of mammographic imaging. Therefore, the radiographer’s knowledge on QA is greatly instrumental in routine mammographic practice. The aim of this study was to assess the radiographer’s knowledge on Quality Assurance and Quality Control programmes in relation to mammographic procedures. A cross-sectional study was carried out among all radiographers working in each mammography setting in Sri Lanka. Pre-tested, anonymous self-administered questionnaires were circulated among the study population and duly filled questionnaires returned within a period of three months were taken into the account. The data on demographical information, knowledge on QA programme and associated QC tests, overall knowledge on QA and QC programmes were obtained. Data analysis was performed using IBM SPSS statistical software (version 20.0). The total response rate was 59.6% and the average knowledge score was 54.15±11.29 SD out of 100. Knowledge was compared on the basis of education level, special training of mammography, and the years of working experience in a mammographic setting of the individuals. Out of 31 subjects, 64.5% (n=20) were graduate radiographers and 35.5% (n=11) were diploma holders while 83.9% (n=26) of radiographers have been specially trained for mammography and 16.1% (n=5) have not been attended for any special training for mammography. It is also noted that 58.1% (n=18) of individuals possessed their experience of less than one year and rest 41.9% (n=13) of them were greater than that. Further, the results found that there is a significant difference (P < 0.05) in the knowledge of QA and overall knowledge on QA and QC programme in the categories of education level and working experience. Also, results imply that there was a significant difference (P < 0.05) in the knowledge of QC test among the groups of trained and non-trained radiographers. This study reveals that education level, working experience and the training obtained particularly in the field of mammography have a significant impact on their knowledge on QA and QC in mammography.Keywords: knowledge, mammography, quality assurance, quality control
Procedia PDF Downloads 3301177 A Mega-Analysis of the Predictive Power of Initial Contact within Minimal Social Network
Authors: Cathal Ffrench, Ryan Barrett, Mike Quayle
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It is accepted in social psychology that categorization leads to ingroup favoritism, without further thought given to the processes that may co-occur or even precede categorization. These categorizations move away from the conceptualization of the self as a unique social being toward an increasingly collective identity. Subsequently, many individuals derive much of their self-evaluations from these collective identities. The seminal literature on this topic argues that it is primarily categorization that evokes instances of ingroup favoritism. Apropos to these theories, we argue that categorization acts to enhance and further intergroup processes rather than defining them. More accurately, we propose categorization aids initial ingroup contact and this first contact is predictive of subsequent favoritism on individual and collective levels. This analysis focuses on Virtual Interaction APPLication (VIAPPL) based studies, a software interface that builds on the flaws of the original minimal group studies. The VIAPPL allows the exchange of tokens in an intra and inter-group manner. This token exchange is how we classified the first contact. The study involves binary longitudinal analysis to better understand the subsequent exchanges of individuals based on who they first interacted with. Studies were selected on the criteria of evidence of explicit first interactions and two-group designs. Our findings paint a compelling picture in support of a motivated contact hypothesis, which suggests that an individual’s first motivated contact toward another has strong predictive capabilities for future behavior. This contact can lead to habit formation and specific favoritism towards individuals where contact has been established. This has important implications for understanding how group conflict occurs, and how intra-group individual bias can develop.Keywords: categorization, group dynamics, initial contact, minimal social networks, momentary contact
Procedia PDF Downloads 1481176 Comparison of Efficacy between Low-Residue Diet and Clear-Liquid Diet in Colonoscopic Bowel Preparation at a Surgical Clinic: A Randomized Controlled Trial
Authors: Sopana Wongtawee
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Purpose: Adequate bowel cleansing is essential for a high quality, effective and safe colonoscopy. The aims of this study were to compare the efficacy of bowel preparation based on a low-residue diet before 8:00 followed by a clear-liquid diet, and a low-residue diet until 16:00 one day before colonoscopy using sodium phosphate solution (Xubil ®), the side effects of the two protocols and the patient satisfaction with them. Method: This was an endoscopist-blinded, prospective, randomized, controlled trial. A total of 224 patients (112 in each group) scheduled for outpatient colonoscopy met the criteria.They were randomized to either a low-residue diet consisting of white rice porridge with either fish, chicken or eggs before 8:00 followed by a clear-liquid diet (Group 1) or a low-residue diet consisting of the same food and drink, until 16:00 the day before colonoscopy(Group 2). All of them received 45 ml of sodium phosphate solution (Xubil ®) and three glasses of water (300 ml/glass) the evening before and the morning of the procedure. The cleansing efficacy of bowel preparation was rated according to the modified Rajawithi hospital bowel preparation score scale, patient satisfaction with bowel preparation was rated using Likert scale, and side effects of the 2 protocols was assessed using a patient questionnaire. Results: The cleansing efficacy between the two groups was significantly different (p=0.02). Satisfaction with bowel preparation and side effects were not different, except for the feeling of hunger in the first group (p=0.001). Conclusion: The low-residue diet consisting of white rice porridge with fish, chicken or eggs until 16:00 one day before colonoscopy achieved a better bowel-cleansing efficacy than the protocol consisting of clear liquid all day and rice porridge only before 8:00 one day before colonoscopy.Keywords: bowel preparation, colonoscopy, sodium phosphate solution, nursing management
Procedia PDF Downloads 3931175 A Sustainable Design Model by Integrated Evaluation of Closed-loop Design and Supply Chain Using a Mathematical Model
Authors: Yuan-Jye Tseng, Yi-Shiuan Chen
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The paper presented a sustainable design model for integrated evaluation of the design and supply chain of a product for the sustainable objectives. To design a product, there can be alternative ways to assign the detailed specifications to fulfill the same design objectives. In the design alternative cases, different material and manufacturing processes with various supply chain activities may be required for the production. Therefore, it is required to evaluate the different design cases based on the sustainable objectives. In this research, a closed-loop design model is developed by integrating the forward design model and reverse design model. From the supply chain point of view, the decisions in the forward design model are connected with the forward supply chain. The decisions in the reverse design model are connected with the reverse supply chain considering the sustainable objectives. The purpose of this research is to develop a mathematical model for analyzing the design cases by integrated evaluating the criteria in the closed-loop design and the closed-loop supply chain. The decision variables are built to represent the design cases of the forward design and reverse design. The cost parameters in a forward design include the costs of material and manufacturing processes. The cost parameters in a reverse design include the costs of recycling, disassembly, reusing, remanufacturing, and disposing. The mathematical model is formulated to minimize the total cost under the design constraints. In practical applications, the decisions of the mathematical model can be used for selecting a design case for the purpose of sustainable design of a product. An example product is demonstrated in the paper. The test result shows that the sustainable design model is useful for integrated evaluation of the design and the supply chain to achieve the sustainable objectives.Keywords: closed-loop design, closed-loop supply chain, design evaluation, supply chain management, sustainable design model
Procedia PDF Downloads 4251174 Evaluation of Antibiotic Resistance Profiles of Staphlyococci Isolated from Various Clinical Specimens
Authors: Recep Kesli, Merih Simsek, Cengiz Demir, Onur Turkyilmaz
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Objective: Goal of this study was to determine the antibiotic resistance of Staphylococcus aureus (S. aureus) and Methicillin resistant staphylococcus aureus (MRSA) strains isolated at Medical Microbiology Laboratory of ANS Application and Research Hospital, Afyon Kocatepe University, Turkey. Methods: S. aureus strains isolated between October 2012 and September 2016, from various clinical specimens were evaluated retrospectively. S. aureus strains were identified by both the conventional methods and automated identification system -VITEK 2 (bio-Mérieux, Marcy l’etoile, France), and Meticillin resistance was verified using oxacillin disk with disk-diffusion method. Antibiotic resistance testing was performed by Kirby-Bauer disc diffusion method according to CLSI criteria, and intermediate susceptible strains were considered as resistant. Results: Seven hundred S.aureus strains which were isolated from various clinical specimens were included in this study. These strains were mostly isolated from blood culture, tissue, wounds and bronchial aspiration. All of 306 (43,7%) were oxacillin resistant. While all the S.aureus strains were found to be susceptible to vancomycin, teicoplanin, daptomycin and linezolid, 38 (9.6 %), 77 (19.5 %), 116 (29.4 %), 152 (38.6 %) and 28 (7.1 %) were found to be resistant aganist to clindamycin, erythromycin, gentamicin, tetracycline and sulfamethoxazole/trimethoprim, retrospectively. Conclusions: Comparing to the Methicillin sensitive staphylococcus aureus (MSSA) strains, increased resistance rates of, trimethoprim-sulfamethoxazole, clindamycin, erythromycin, gentamicin, and tetracycline were observed among the MRSA strains. In this study, the most effective antibiotic on the total of strains was found to be trimethoprim-sulfamethoxazole, the least effective antibiotic on the total of strains was found to be tetracycline.Keywords: antibiotic resistance, MRSA, Staphylococcus aureus, VITEK 2
Procedia PDF Downloads 2531173 Fundamental Natural Frequency of Chromite Composite Floor System
Authors: Farhad Abbas Gandomkar, Mona Danesh
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This paper aims to determine Fundamental Natural Frequency (FNF) of a structural composite floor system known as Chromite. To achieve this purpose, FNFs of studied panels are determined by development of Finite Element Models (FEMs) in ABAQUS program. American Institute of Steel Construction (AISC) code in Steel Design Guide Series 11, presents a fundamental formula to calculate FNF of a steel framed floor system. This formula has been used to verify results of the FEMs. The variability in the FNF of the studied system under various parameters such as dimensions of floor, boundary conditions, rigidity of main and secondary beams around the floor, thickness of concrete slab, height of composite joists, distance between composite joists, thickness of top and bottom flanges of the open web steel joists, and adding tie beam perpendicular on the composite joists, is determined. The results show that changing in dimensions of the system, its boundary conditions, rigidity of main beam, and also adding tie beam, significant changes the FNF of the system up to 452.9%, 50.8%, -52.2%, %52.6%, respectively. In addition, increasing thickness of concrete slab increases the FNF of the system up to 10.8%. Furthermore, the results demonstrate that variation in rigidity of secondary beam, height of composite joist, and distance between composite joists, and thickness of top and bottom flanges of open web steel joists insignificant changes the FNF of the studied system up to -0.02%, -3%, -6.1%, and 0.96%, respectively. Finally, the results of this study help designer predict occurrence of resonance, comfortableness, and design criteria of the studied system.Keywords: Fundamental Natural Frequency, Chromite Composite Floor System, Finite Element Method, low and high frequency floors, Comfortableness, resonance.
Procedia PDF Downloads 4571172 Product Separation of Green Processes and Catalyst Recycling of a Homogeneous Polyoxometalate Catalyst Using Nanofiltration Membranes
Authors: Dorothea Voß, Tobias Esser, Michael Huber, Jakob Albert
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The growing world population and the associated increase in demand for energy and consumer goods, as well as increasing waste production, requires the development of sustainable processes. In addition, the increasing environmental awareness of our society is a driving force for the requirement that processes must be as resource and energy efficient as possible. In this context, the use of polyoxometalate catalysts (POMs) has emerged as a promising approach for the development of green processes. POMs are bifunctional polynuclear metal-oxo-anion cluster characterized by a strong Brønsted acidity, a high proton mobility combined with fast multi-electron transfer and tunable redox potential. In addition, POMs are soluble in many commonly known solvents and exhibit resistance to hydrolytic and oxidative degradation. Due to their structure and excellent physicochemical properties, POMs are efficient acid and oxidation catalysts that have attracted much attention in recent years. Oxidation processes with molecular oxygen are worth mentioning here. However, the fact that the POM catalysts are homogeneous poses a challenge for downstream processing of product solutions and recycling of the catalysts. In this regard, nanofiltration membranes have gained increasing interest in recent years, particularly due to their relative sustainability advantage over other technologies and their unique properties such as increased selectivity towards multivalent ions. In order to establish an efficient downstream process for the highly selective separation of homogeneous POM catalysts from aqueous solutions using nanofiltration membranes, a laboratory-scale membrane system was designed and constructed. By varying various process parameters, a sensitivity analysis was performed on a model system to develop an optimized method for the recovery of POM catalysts. From this, process-relevant key figures such as the rejection of various system components were derived. These results form the basis for further experiments on other systems to test the transferability to serval separation tasks with different POMs and products, as well as for recycling experiments of the catalysts in processes on laboratory scale.Keywords: downstream processing, nanofiltration, polyoxometalates, homogeneous catalysis, green chemistry
Procedia PDF Downloads 891171 Batch and Dynamic Investigations on Magnesium Separation by Ion Exchange Adsorption: Performance and Cost Evaluation
Authors: Mohamed H. Sorour, Hayam F. Shaalan, Heba A. Hani, Eman S. Sayed
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Ion exchange adsorption has a long standing history of success for seawater softening and selective ion removal from saline sources. Strong, weak and mixed types ion exchange systems could be designed and optimized for target separation. In this paper, different types of adsorbents comprising zeolite 13X and kaolin, in addition to, poly acrylate/zeolite (AZ), poly acrylate/kaolin (AK) and stand-alone poly acrylate (A) hydrogel types were prepared via microwave (M) and ultrasonic (U) irradiation techniques. They were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The developed adsorbents were evaluated on bench scale level and based on assessment results, a composite bed has been formulated for performance evaluation in pilot scale column investigations. Owing to the hydrogel nature of the partially crosslinked poly acrylate, the developed adsorbents manifested a swelling capacity of about 50 g/g. The pilot trials have been carried out using magnesium enriched Red Seawater to simulate Red Seawater desalination brine. Batch studies indicated varying uptake efficiencies, where Mg adsorption decreases according to the following prepared hydrogel types AU>AM>AKM>AKU>AZM>AZU, being 108, 107, 78, 69, 66 and 63 mg/g, respectively. Composite bed adsorbent tested in the up-flow mode column studies indicated good performance for Mg uptake. For an operating cycle of 12 h, the maximum uptake during the loading cycle approached 92.5-100 mg/g, which is comparable to the performance of some commercial resins. Different regenerants have been explored to maximize regeneration and minimize the quantity of regenerants including 15% NaCl, 0.1 M HCl and sodium carbonate. Best results were obtained by acidified sodium chloride solution. In conclusion, developed cation exchange adsorbents comprising clay or zeolite support indicated adequate performance for Mg recovery under saline environment. Column design operated at the up-flow mode (approaching expanded bed) is appropriate for such type of separation. Preliminary cost indicators for Mg recovery via ion exchange have been developed and analyzed.Keywords: batch and dynamic magnesium separation, seawater, polyacrylate hydrogel, cost evaluation
Procedia PDF Downloads 1351170 Surgical Management of Distal Femur Fracture Using Locking Compression Plate: Our Experience in a Rural Tertiary Care Centre in India
Authors: Pagadaplly Girish, P. V. Manohar
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Introduction: Management of distal femur fractures is challenging. Recently, treatment has evolved towards indirect reduction and minimally invasive techniques. Objectives: To assess the fracture union and functional outcome following open reduction and internal fixation of distal femur fractures with locking compression plate and to achieve restoration of the anatomical alignment of fracture fragments and stable internal fixation. Methodology: Patients with distal femur fracture treated by locking compression during Oct 2011 to April 2013 were assessed prospectively. Patients below 18 years and those with neuro-vascular deficits were excluded. Age, sex of the patient, type of fracture, mechanism of injury, type of implant used, operative time and postoperative complications were analysed. The Neer’s scale was used to assess the outcome of the patients. Results: The total number of patients was 30; 28 males and 2 females; mean age was 41.53 years. Road traffic accidents were the major causes of injury followed by falls. The average duration of hospital stay was 21.3 days. The overall complication rate note was 23.33%. The mean range of movement around the knee joint after 6 months of follow-up was 114.330. The average time for the radiological union was 14 weeks. Excellent to good results were noted in 26 patients (86.6%) and average to poor results were observed in 4 (13.33%) patients. Conclusions: The locking compression plate gives a rigid fixation for the fracture. It also provides a good purchase in osteoporotic bones. LCP is simple and a reliable implant appropriate for fixation of femoral fractures with promising results.Keywords: distal femur fractures, locking compression plate, Neer’s criteria, neuro-vascular deficits
Procedia PDF Downloads 2501169 Beyond Diagnosis: Innovative Instructional Methods for Children with Multiple Disabilities
Authors: Patricia Kopetz
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Too often our youngest children with disabilities receive diagnostic labels and accompanying treatment plans based upon perceptions that the children are of limited aptitude and/or ambition. However, children of varied-ability levels who are diagnosed with ‘multiple disabilities,’ can participate and excel in school-based instruction that aligns with their desires, interests, and fortitude – criteria components not foretold by scores on standardized assessments. The paper represents theoretical work in Special Education Innovative Instruction, and includes presenting research materials, some developed by the author herself. The majority of students with disabilities are now served in general education settings in the United States, embracing inclusive practices in our schools. ‘There is now a stronger call for special education to step up and improve efficiency, implement evidence-based practices, and provide greater accountability on key performance indicators that support successful academic and post-school outcomes for students with disabilities.’ For example, in the United States, the Office of Special Education Programs (OSEP) is focusing on results-driven indicators to improve outcomes for students with disabilities. School personnel are appreciating the implications of research-driven approaches for students diagnosed with multiple disabilities, and aim to align their practices toward such focus. The paper presented will provide updates on current theoretical principles and perspectives, and explore advancements in latest, evidence-based and results-driven instructional practices that can motivate children with multiple disabilities to advance their skills and engage in learning activities that as nonconventional, innovative, and proven successful.Keywords: childhood special education, educational technology , innovative instruction, multiple disabilities
Procedia PDF Downloads 2491168 Nursing Documentation of Patients' Information at Selected Primary Health Care Facilities in Limpopo Province, South Africa: Implications for Professional Practice
Authors: Maria Sonto Maputle, Rhulani C. Shihundla, Rachel T. Lebese
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Background: Patients’ information must be complete and accurately documented in order to foster quality and continuity of care. The multidisciplinary health care members use patients’ documentation to communicate about health status, preventive health services, treatment, planning and delivery of care. The purpose of this study was to determine the practice of nursing documentation of patients’ information at selected Primary Health Care (PHC) facilities in Vhembe District, Limpopo Province, South Africa. Methods: The research approach adopted was qualitative while exploratory and descriptive design was used. The study was conducted at selected PHC facilities. Population included twelve professional nurses. Non-probability purposive sampling method was used to sample professional nurses who were willing to participate in the study. The criteria included participants’ whose daily work and activities, involved creating, keeping and updating nursing documentation of patients’ information. Qualitative data collection was through unstructured in-depth interviews until no new information emerged. Data were analysed through open–coding of, Tesch’s eight steps method. Results: Following data analysis, it was found that professional nurses’ had knowledge deficit related to insufficient training on updates and rendering multiple services daily had negative impact on accurate documentation of patients’ information. Conclusion: The study recommended standardization of registers, books and forms used at PHC facilities, and reorganization of PHC services into open day system.Keywords: documentation, knowledge, patient care, patient’s information, training
Procedia PDF Downloads 1901167 Virtue, Truth, Freedom, And The History Of Philosophy
Authors: Ashley DelCorno
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GEM Anscombe’s 1958 essay Modern Moral Philosophy and the tradition of virtue ethics that followed has given rise to the restoration (or, more plainly, the resurrection) of Aristotle as something of an authority figure. Alisdair MacIntyre and Martha Nussbaum are proponents, for example, not just of Aristotle’s relevancy but also of his apparent implicit authority. That said, it’s not clear that the schema imagined by virtue ethicists accurately describes moral life or that it does not inadvertently work to impoverish genuine decision-making. If the label ‘virtue’ is categorically denied to some groups (while arbitrarily afforded to others), it can only turn on itself, thus rendering ridiculous its own premise. Likewise, as an inescapable feature of virtue ethics, Aristotelean binaries like ‘virtue/vice’ and ‘voluntary/involuntary’ offer up false dichotomies that may seriously compromise an agent’s ability to conceptualize choices that are truly free and rooted in meaningful criteria. Here, this topic is analyzed through a feminist lens predicated on the known paradoxes of patriarchy. The work of feminist theorists Jacqui Alexander, Katharine Angel, Simone de Beauvoir, bell hooks, Audre Lorde, Imani Perry, and Amia Srinivasan serves as important guideposts, and the argument here is built from a key tenet of black feminist thought regarding scarcity and possibility. Above all, it’s clear that though the philosophical tradition of virtue ethics presents itself as recovering the place of agency in ethics, its premises possess crippling limitations toward the achievement of this goal. These include, most notably, virtue ethics’ binding analysis of history, as well as its axiomatic attachment to obligatory clauses, problematic reading-in of Aristotle and arbitrary commitment to predetermined and competitively patriarchal ideas of what counts as a virtue.Keywords: feminist history, the limits of utopic imagination, curatorial creation, truth, virtue, freedom
Procedia PDF Downloads 821166 Trial of Resorbable versus Non-Resorbable Sutures for Traumatic Lacerations of the Face: A Demonstration of Maxillo-Facial Trainee Led Research
Authors: R. Botrugno, S Basyuni, G. Nugent, I. Jenkyn, A. Ferro, H. Bennett, C. Hjalmarsson, J. Chu, V. Santhanam
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This trainee led randomised controlled trial (RCT) aims to assess various outcomes for resorbable versus non-resorbable sutures for traumatic lacerations to the face. Within this trial of resorbable versus non-resorbable sutures for traumatic lacerations of the face (TORNFace), patient recruitment was facilitated by trainees who were employed at an NHS University Teaching Hospital in the United Kingdom. The trainees received appropriate training prior to recruiting patients for the trial. This included the completion of a national research e-learning module and face-to-face training that was provided locally. The locally delivered training provided an understanding of the eligibility criteria for the trial and the consent process. Existing trainee skills were utilised involving clinical photography to record baseline data and delivering the intervention based on the treatment arm selected. Eligible patients who required primary closure of traumatic lacerations of the face were randomised into one of two treatment arms. These comprised of resorbable (vicryl rapide) or non-resorbable sutures (ethilon). Primarily the cosmetic outcome was assessed. Secondary outcomes included: complications rates, health care economics, and patient-reported outcomes. Remote follow-up of recruited patients utilised photographs of the facial laceration which had received the intervention. These took place at 1 week, 3 months and 6 months post-intervention. This study aims to demonstrate an example of trainee-led research within the specialty of oral and maxillofacial surgery. The available data for the randomised controlled trial will also be presented.Keywords: laceration, suture, trauma, trial
Procedia PDF Downloads 1371165 Mental Disorders and Physical Illness in Geriatric Population
Authors: Vinay Kumar, M. Kishor, Sathyanarayana Rao Ts
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Background: Growth of elderly people in the general population in recent years is termed as ‘greying of the world’ where there is a shift from high mortality & fertility to low mortality and fertility, resulting in an increased proportion of older people as seen in India. Improved health care promises longevity but socio-economic factors like poverty, joint families and poor services pose a psychological threat. Epidemiological data regarding the prevalence of mental disorders in geriatric population with physical illness is required for proper health planning. Methods: Sixty consecutive elderly patients aged 60 years or above of both sexes, reporting with physical illness to general outpatient registration counter of JSS Medical College and Hospital, Mysore, India, were considered for the Study. With informed consent, they were screened with General Health Questionnaire (GHQ-12) and were further evaluated for diagnosing mental disorders according to WHO International Classification of Diseases (ICD-10) criteria. Results: Mental disorders were detected in 48.3%, predominantly depressive disorders, nicotine dependence, generalized anxiety disorder, alcohol dependence and least was dementia. Most common physical illness was cardiovascular disease followed by metabolic, respiratory and other diseases. Depressive disorders, substance dependence and dementia were more associated with cardiovascular disease compared to metabolic disease and respiratory diseases were more associated with nicotine dependence. Conclusions: Depression and Substance use disorders among elderly population is of concern, which needs to be further studied with larger population. Psychiatric morbidity will adversely have an impact on physical illness which needs proper assessment and management. This will enhance our understanding and prioritize our planning for future.Keywords: Geriatric, mental disorders, physical illness, psychiatry
Procedia PDF Downloads 2861164 Tourist’s Perception and Identification of Landscape Elements of Traditional Village
Authors: Mengxin Feng, Feng Xu, Zhiyong Lai
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As a typical representative of the countryside, traditional Chinese villages are rich in cultural landscape resources and historical information, but they are still in continuous decline. The problems of people's weak protection awareness and low cultural recognition are still serious, and the protection of cultural heritage is imminent. At the same time, with the rapid development of rural tourism, its cultural value has been explored and paid attention to again. From the perspective of tourists, this study aimed to explore people's perception and identity of cultural landscape resources under the current cultural tourism development background. We selected eleven typical landscape elements of Lingshui Village, a traditional village in Beijing, as research objects and conducted a questionnaire survey with two scales of perception and identity to explore the characteristics of people's perception and identification of landscape elements. We found that there was a strong positive correlation between the perception and identity of each element and that geographical location influenced visitors' overall perception. The perception dimensions scored the highest in location, and the lowest in history and culture, and the identity dimensions scored the highest in meaning and lowest in emotion. We analyzed the impact of visitors' backgrounds on people's perception and identity characteristics and found that age and education were two important factors. The elderly had a higher degree of perceived identity, as the familiarity effect increased their attention. Highly educated tourists had more stringent criteria for perception and identification. The above findings suggest strategies for conserving and optimizing landscape elements in the traditional village to improve the acceptance and recognition of cultural information in traditional villages, which will inject new vitality into the development of traditional villages.Keywords: traditional village, tourist perception, landscape elements, perception and identity
Procedia PDF Downloads 1461163 Impact of Social Distancing on the Correlation Between Adults’ Participation in Learning and Acceptance of Technology
Authors: Liu Yi Hui
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The COVID-19 pandemic in 2020 has globally affected all aspects of life, with social distancing and quarantine orders causing turmoil and learning in community colleges being temporarily paused. In fact, this is the first time that adult education has faced such a severe challenge. It forces researchers to reflect on the impact of pandemics on adult education and ways to respond. Distance learning appears to be one of the pedagogical tools capable of dealing with interpersonal isolation and social distancing caused by the pandemic. This research aims to examine whether the impact of social distancing during COVID-19 will lead to increased acceptance of technology and, subsequently, an increase in adults ’ willingness to participate in distance learning. The hypothesis that social distancing and the desire to participate in distance learning affects learners’ tendency to accept technology is investigated. Teachers ’ participation in distance education and acceptance of technology are used as adjustment variables with the relationship to “social distancing,” “participation in distance learning,” and “acceptance of technology” of learners. A questionnaire survey was conducted over a period of twelve months for teachers and learners at all community colleges in Taiwan who enrolled in a basic unit course. Community colleges were separated using multi-stage cluster sampling, with their locations being metropolitan, non-urban, south, and east as criteria. Using the G*power software, 660 samples were selected and analyzed. The results show that through appropriate pedagogical strategies or teachers ’ own acceptance of technology, adult learners’ willingness to participate in distance learning could be influenced. A diverse model of participation can be developed, improving adult education institutions’ ability to plan curricula to be flexible to avoid the risk associated with epidemic diseases.Keywords: social distancing, adult learning, community colleges, technology acceptance model
Procedia PDF Downloads 1401162 Comparison of E-learning and Face-to-Face Learning Models Through the Early Design Stage in Architectural Design Education
Authors: Gülay Dalgıç, Gildis Tachir
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Architectural design studios are ambiencein where architecture design is realized as a palpable product in architectural education. In the design studios that the architect candidate will use in the design processthe information, the methods of approaching the design problem, the solution proposals, etc., are set uptogetherwith the studio coordinators. The architectural design process, on the other hand, is complex and uncertain.Candidate architects work in a process that starts with abstre and ill-defined problems. This process starts with the generation of alternative solutions with the help of representation tools, continues with the selection of the appropriate/satisfactory solution from these alternatives, and then ends with the creation of an acceptable design/result product. In the studio ambience, many designs and thought relationships are evaluated, the most important step is the early design phase. In the early design phase, the first steps of converting the information are taken, and converted information is used in the constitution of the first design decisions. This phase, which positively affects the progress of the design process and constitution of the final product, is complex and fuzzy than the other phases of the design process. In this context, the aim of the study is to investigate the effects of face-to-face learning model and e-learning model on the early design phase. In the study, the early design phase was defined by literature research. The data of the defined early design phase criteria were obtained with the feedback graphics created for the architect candidates who performed e-learning in the first year of architectural education and continued their education with the face-to-face learning model. The findings of the data were analyzed with the common graphics program. It is thought that this research will contribute to the establishment of a contemporary architectural design education model by reflecting the evaluation of the data and results on architectural education.Keywords: education modeling, architecture education, design education, design process
Procedia PDF Downloads 1371161 Challenges of Landscape Design with Tree Species Diversity
Authors: Henry Kuppen
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In the last decade, tree managers have faced many threats of pests and diseases and the effects of climate change. Managers will recognize that they have to put more energy and more money into tree management. By recognizing the cause behind this, the opportunity will arise to build sustainable tree populations for the future. More and more, unwanted larvae are sprayed, ash dieback infected trees are pruned or felled, and emerald ash borer is knocking at the door of West Europe. A lot of specific knowledge is needed to produce management plans and best practices. If pest and disease have a large impact, society loses complete tree species and need to start all over again building urban forest. But looking at the cause behind it, landscape design, and tree species selection, the sustainable solution does not present itself in managing these threats. Every pest or disease needs two important basic ingredients to be successful: climate and food. The changing climate is helping several invasive pathogens to survive. Food is often designed by the landscapers and managers of the urban forest. Monocultures promote the success of pathogens. By looking more closely at the basics, tree managers will realise very soon that the solution will not be the management of pathogens. The long-term solution for sustainable tree populations is a different design of our urban landscape. The use of tree species diversity can help to reduce the impact of climate change and pathogens. Therefore landscapers need to be supported. They are the specialists in designing the landscape using design values like canopy volume, ecosystem services, and seasonal experience. It’s up to the species specialist to show what the opportunities are for different species that meet the desired interpretation of the landscape. Based on landscapers' criteria, selections can be made, including tree species related requirements. Through this collaboration and formation of integral teams, sustainable plant design will be possible.Keywords: climate change, landscape design, resilient landscape, tree species selection
Procedia PDF Downloads 1301160 A Semidefinite Model to Quantify Dynamic Forces in the Powertrain of Torque Regulated Bascule Bridge Machineries
Authors: Kodo Sektani, Apostolos Tsouvalas, Andrei Metrikine
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The reassessment of existing movable bridges in The Netherlands has created the need for acceptance/rejection criteria to assess whether the machineries are meet certain design demands. However, the existing design code defines a different limit state design, meant for new machineries which is based on a simple linear spring-mass model. Observations show that existing bridges do not confirm the model predictions. In fact, movable bridges are nonlinear systems consisting of mechanical components, such as, gears, electric motors and brakes. Next to that, each movable bridge is characterized by a unique set of parameters. However, in the existing code various variables that describe the physical characteristics of the bridge are neglected or replaced by partial factors. For instance, the damping ratio ζ, which is different for drawbridges compared to bascule bridges, is taken as a constant for all bridge types. In this paper, a model is developed that overcomes some of the limitations of existing modelling approaches to capture the dynamics of the powertrain of a class of bridge machineries First, a semidefinite dynamic model is proposed, which accounts for stiffness, damping, and some additional variables of the physical system, which are neglected by the code, such as nonlinear braking torques. The model gives an upper bound of the peak forces/torques occurring in the powertrain during emergency braking. Second, a discrete nonlinear dynamic model is discussed, with realistic motor torque characteristics during normal operation. This model succeeds to accurately predict the full time history of the occurred stress state of the opening and closing cycle for fatigue purposes.Keywords: Dynamics of movable bridges, Bridge machinery, Powertrains, Torque measurements
Procedia PDF Downloads 156