Search results for: benchmark level

Authors: Erica Cochran Hameen, Bobuchi Ken-Opurum, Shalini Priyadarshini, Berangere Lartigue, Sadhana Anath-Pisipati

Abstract:

School districts throughout the United States are constantly seeking measures to improve test scores, reduce school absenteeism and improve indoor environmental quality. It is imperative to identify key building investments which will provide the largest benefits to schools in terms of improving the aforementioned factors. This study uses Analysis of Variance (ANOVA) tests to statistically evaluate the impact of a school building’s mechanical and plumbing characteristics on a child’s educational performance. The educational performance is measured via three indicators, i.e. test scores, suspensions, and absenteeism. The study investigated 125 New York City school facilities to determine the potential correlations between 50 mechanical and plumbing variables and the performance indicators. Key findings from the tests revealed that elementary schools with pneumatic systems in “good” condition have 48.8% lower percentages of students scoring at the minimum English Language Arts (ELA) competency level compared with those with no pneumatic system. Additionally, elementary schools with “unit heaters/cabinet heaters” in “good to fair” conditions have 1.1% higher attendance rates compared to schools with no “unit heaters/cabinet heaters” or those in inferior condition. Furthermore, elementary schools with air conditioning have 0.6% higher attendance rates compared to schools with no air conditioning, and those with interior floor drains in “good” condition have 1.8% higher attendance rates compared to schools with interior drains in inferior condition.

Keywords: academic attendance and performance, mechanical and plumbing systems, schools, student health

Procedia PDF Downloads 118

Authors: C. Mayuren, C. K. Paul Wang, K. Purushotham, C. Dinesh Kumar

Abstract:

Diabetes Mellitus (DM) is one of the most common non-communicable diseases globally. Although significant advances have led to better understanding of the condition and the development of effective therapies and preventive strategies, the pathway to cure remains elusive and DM prevails as a serious medical challenge in the 21st century. Oxidative stress has been suggested to contribute to the progression and pathophysiological conditions of diabetes. Madecassoside (MA) a major pentacyclic triterpenoid, has been demonstrated to possess various biological activities. However, no attempt has been made to study the antioxidant activity in diabetic rats. Therefore, the present study is aimed to evaluate the antioxidant effect of MA on streptozotocin-nicotinamide induced type-2 diabetes in Sprague-Dawley rats. The study protocol was approved by the institutional ethical committee prior to the conduct of research. Adult male Sprague-Dawley rats weighing 250-300 g were used in the study. The animals were rendered diabetic with a single intraperitoneal dose of streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg). The diabetic animals after a stabilisation period of 14 days received various treatments (Madecassoside 50 mg/kg; Glimepiride 2.5 mg/kg) suspended in 0.5% carboxymethyl cellulose orally, for a period of 28 days. The animals fasted overnight after the last treatment were sacrificed and the pancreas, liver and kidneys were isolated. The weighted quantity of the samples of various treatments were homogenised in ice-cold condition and were subjected to lipid peroxidation, catalase and superoxide dismutase assay. The data’s obtained were subjected to statistical analysis. Diabetic rats showed significant increase in lipid peroxidation and decrease in enzymatic antioxidant levels. All the treated groups had significantly higher SOD, CAT and reduced LPO activity in the pancreas, liver and kidney. Results suggest madecassoside to have potential antioxidant effect against the diabetic model. However further investigations are necessary to study the mechanism at the cellular level.

Keywords: antioxidant, diabetes, madecassoside, nicotinamide, streptozotocin

Procedia PDF Downloads 379

Authors: Molla Tadesse Lakew

Abstract:

This study was intended to identify the factors influencing the use of mobile phones in vegetable marketing in Fogera district. The use of mobile phones in vegetable marketing and factors influencing mobile phone use were specific objectives of the study. Three kebeles from the Fogera district were selected purposively based on their vegetable production potential. A simple random sampling technique (lottery method) was used to select 153 vegetable producer farmers. Interview schedule and key informants interviews were used to collect primary data. For analyzing the data, descriptive statistics like frequency and percentage, two independent t-tests, and chi-square were used. Furthermore, econometric analysis (binary logistic model) was used to assess the factors influencing mobile phone use for vegetable market information. Contingency coefficient and variance inflation factor were used to check multicollinearity problems between the independent variables. Of 153 respondents, 82 (61.72%) were mobile phone users, while 71 (38.28 %) were mobile phone nonusers. Moreover, the main use of mobile phones in vegetable marketing includes communicating at a distance to save time and minimizing transport costs, getting vegetable marketing price information, identifying markets and buyers to sell the vegetable, deciding when to sell the vegetable, negotiating with buyers for better vegetable prices and for searching of the fast market to avoid from losing of product through perishing. The model result indicated that the level of education, size of land, income, access to credit, and age were significant variables affecting the use of mobile phones in vegetable marketing. It could be recommended to encourage adult education or give training for farmers on how to operate mobile phones and create awareness for the elderly rural farmers as they are able to use the mobile phone for their vegetable marketing. Moreover, farmers should be aware that mobile phones are very important for those who own very small land to get maximum returns from their production. Lastly, providing access to credit and improving and diversifying income sources for the farmers to have mobile phones were recommended to improve the livelihood of farmers.

Keywords: mobile phone, farmers, vegetable marketing, Fogera District

Procedia PDF Downloads 73

Authors: Cristian Soitu, Alexander Feuerborn, Cyril Deroy, Alfonso Castrejon-Pita, Peter R. Cook, Edmond J. Walsh

Abstract:

Microfluidics now stands as an academically mature technology after a quarter of a century research activities have delivered a vast array of proof of concepts for many biological workflows. However, translation to industry remains poor, with only a handful of notable exceptions – e.g. digital PCR, DNA sequencing – mainly because of biocompatibility issues, limited range of readouts supported or complex operation required. This technology exploits the domination of interfacial forces over gravitational ones at the microscale, replacing solid walls with fluid ones as building blocks for cell micro-environments. By employing only materials used by biologists for decades, the system is shown to be biocompatible, and easy to manufacture and operate. The method consists in displacing a continuous fluid layer into a pattern of isolated chambers overlaid with an immiscible liquid to prevent evaporation. The resulting fluid arrangements can be arrays of micro-chambers with rectangular footprint, which use the maximum surface area available, or structures with irregular patterns. Pliant, self-healing fluid walls confine volumes as small as 1 nl. Such fluidic structures can be reconfigured during the assays, giving the platform an unprecedented level of flexibility. Common workflows in cell biology are demonstrated – e.g. cell growth and retrieval, cloning, cryopreservation, fixation and immunolabeling, CRISPR-Cas9 gene editing, and proof-of-concept drug tests. This fluid-shaping technology is shown to have potential for high-throughput cell- and organism-based assays. The ability to make and reconfigure on-demand microfluidic circuits on standard Petri dishes should find many applications in biology, and yield more relevant phenotypic and genotypic responses when compared to standard microfluidic assays.

Keywords: fluid walls, micro-chambers, reconfigurable, freestyle

Procedia PDF Downloads 193

Authors: Batool Ismaeel, Umair Farooq, Saad Mushtaq

Abstract:

Construction projects in the oil industry can be very complex, having unknown outcomes and uncertainties that cannot be easily predicted. Each project has its unique risks generated by a number of factors which, if not controlled, will impact the successful completion of the project mainly in terms of schedule, cost, quality, and safety. This paper highlights the historic risks associated with projects in the south and east region of Kuwait Oil Company (KOC) collated from the company’s lessons learned database. Starting from Contract Award through to handover of the project to the Asset owner, the gaps in project execution in terms of managing risk will be brought to discussion and where a well-defined systematic approach in project risk management reflecting many claims, change of scope, exceeding budget, delays in engineering phase as well as in the procurement and fabrication of long lead items should be adopted. This study focuses on a proposed feasible approach in risk management for engineering, procurement and construction (EPC) level projects including the various stakeholders involved in executing the works from International to local contractors and vendors in KOC. The proposed approach covers the areas categorized into organizational, design, procurement, construction, pre-commissioning, commissioning and project management in which the risks are identified and require management and mitigation. With the effective deployment and implementation of the proposed risk management system and the consideration of it as a vital key in achieving the project’s target, the outcomes will be more predictable in the future, and the risk triggers will be managed and controlled. The correct resources can be allocated on a timely basis for the company for avoiding any unpredictable outcomes during the execution of the project. It is recommended in this paper to apply this risk management approach as an integral part of project management and investigate further in the future, the effectiveness of this proposed system for newly awarded projects and compare the same with those projects of similar budget/complexity that have not applied this approach to risk management.

Keywords: construction, project completion, risk management, uncertainties

Procedia PDF Downloads 153

Authors: Robert Dutkiewicz, Monika Szpringer, Mariola Wojciechowska

Abstract:

Physical activity is one of the factors greatly influencing healthy lifestyle. The recent research into physical activity of the Polish society reveals that contribution of physical culture to healthy lifestyle is insufficient. Students, regardless of age, spend most of free-time in front of a TV or computer. The research attempted to identify the level of physical activity and healthy lifestyle among students of medical sciences and other students doing their teaching degrees. The findings of physical activity research conducted in 2014, which covered 364 students of medical sciences and future teachers from the University of Jan Kochanowski in Kielce were analysed. The research involved the method of diagnostic survey based on a questionnaire. It attempted to establish to what extent such factors as the field of studies, the place of residence and BMI affect students’ physical activity. Empirical material was analysed by means of SPSS/PC, the leading statistical software. The field of study significantly influences physical activity of the respondents. The students of physiotherapy and public health tend to be more physically active than students of biology and geography: 46.8% students of geography and 51.8 % biology students seldom take up physical activity. Obesity and overweight are currently serious problems of university students: 6.6% of them are obese and 19% overweight. It is alarming that these students are not willing to find ways to be more physically active. Most of the obese and overweight respondents study biology or geography and live in a rural area. Unequal chances in terms of youth physical culture are determined by the differences between rural and urban environments. Young people living in rural areas are less physically active, particularly in terms of the frequency and the amount of time devoted to physical activity. This is caused by poor infrastructure to perform physical activity, the lack of or limited number of sports clubs and centres. It is thought-provoking that most of the students claim that they do not have enough time to do sports or other activities, but at the same time they spend a lot of time at a computer or watching TV.

Keywords: BMI, healthy lifestyle, sports activity, students

Procedia PDF Downloads 499

Authors: Oluwafemi Samuel Oyamakin

Abstract:

The forest in Nigeria is currently estimated to extend to around 9.6 million hectares, but used to expand over central and southern Nigeria decades ago. The forest estate is shrinking due to long-term human exploitation for agricultural development, fuel wood demand, uncontrolled forest harvesting and urbanization, amongst other factors, compounded by population growth in rural areas. Nigeria has lost more than 50% of its forest cover since 1990 and currently less than 10% of the country is forested. The current deforestation rate is estimated at 3.7%, which is one of the highest in the world. Reducing Emissions from Deforestation and forest Degradation plus conservation, sustainable management of forests and enhancement of forest carbon stocks constituted what is referred to as REDD+. This study evaluated some of the existing way of computing carbon stocks using eight indigenous tree species like Mansonia, Shorea, Bombax, Terminalia superba, Khaya grandifolia, Khaya senegalenses, Pines and Gmelina arborea. While these components are the essential elements of REDD+ programme, they can be brought under a broader framework of systems analysis designed to arrive at optimal solutions for future predictions through statistical distribution pattern of carbon sequestrated by various species of tree. Available data on height and diameter of trees in Ibadan were studied and their respective potentials of carbon sequestration level were assessed and subjected to tests so as to determine the best statistical distribution that would describe the carbon sequestration pattern of trees. The result of this study suggests a reasonable statistical distribution for carbons sequestered in simulation studies and hence, allow planners and government in determining resources forecast for sustainable development especially where experiments with real-life systems are infeasible. Sustainable management of forest can then be achieved by projecting future condition of forests under different management regimes thereby supporting conservation and REDD+ programmes in Nigeria.

Keywords: REDD+, carbon, climate change, height and diameter

Procedia PDF Downloads 167

Authors: Yong-Kian Lim, Khan Cheung, Xin Dang, Steven Roberts, Xiaotong Wang, Vengatesen Thiyagarajan

Abstract:

Unprecedented rate of increased CO₂ level in the ocean and the subsequent changes in carbonate system including decreased pH, known as ocean acidification (OA), is predicted to disrupt not only the calcification process but also several other physiological and developmental processes in a variety of marine organisms, including edible oysters. Nonetheless, not all species are vulnerable to those OA threats, e.g., some species may be able to cope with OA stress using environmentally induced modifications on gene and protein expressions. For example, external environmental stressors, including OA, can influence the addition and removal of methyl groups through epigenetic modification (e.g., DNA methylation) process to turn gene expression “on or off” as part of a rapid adaptive mechanism to cope with OA. In this study, the above hypothesis was tested through testing the effect of OA, using decreased pH 7.4 as a proxy, on the DNA methylation pattern of an endemic and a commercially important estuary oyster species, Crassostrea hongkongensis, at the time of larval habitat selection and metamorphosis. Larval growth rate did not differ between control pH 8.1 and treatment pH 7.4. The metamorphosis rate of the pediveliger larvae was higher at pH 7.4 than those in control pH 8.1; however, over one-third of the larvae raised at pH 7.4 failed to attach to an optimal substrate as defined by biofilm presence. During larval development, a total of 130 genes were differentially methylated across the two treatments. The differential methylation in the larval genes may have partially accounted for the higher metamorphosis success rate under decreased pH 7.4 but with poor substratum selection ability. Differentially methylated loci were concentrated in the exon regions and appear to be associated with cytoskeletal and signal transduction, oxidative stress, metabolic processes, and larval metamorphosis, which implies the high potential of C. hongkongensis larvae to acclimate and adapt through non-genetic ways to OA threats within a single generation.

Keywords: adaptive plasticity, DNA methylation, larval metamorphosis, ocean acidification

Procedia PDF Downloads 139

Authors: Adebola Adedugbe

Abstract:

The challenge of post-harvest losses poses serious threats for food security in Nigeria and the north-eastern part with the country losing about $9billion annually due to postharvest losses in the sector. Post-harvest loss (PHL) is the quantitative and qualitative loss of food in various post-harvest operations. In Nigeria, post-harvest losses (PHL) have been a major challenge to food security and improved farmer’s income. In 2022, the Nigerian government had said over 30 percent of food produced by Nigerian farmers perish during post-harvest. For many in northeast Nigeria, agriculture is the predominant source of livelihood and income. The persistent communal conflicts, flood, decade-old attacks by boko haram and insurgency in this region have disrupted farming activities drastically, with farmlands becoming insecure and inaccessible as communities are forced to abandon ancestral homes, The impact of climate change is also affecting agricultural and fishing activities, leading to shortage of food supplies, acute hunger and loss of livelihood. This has continued to impact negatively on the region and country’s food production and availability making it loose billions of US dollars annually in income in this sector. The root cause of postharvest losses among others in crops, livestock and fisheries are lack of modern post-harvest equipment, chemical and lack of technologies used for combating losses. The 2019 Global Hunger Index showed Nigeria’s case was progressing from a ‘serious to alarming level’. As part of measures to address the problem of post-harvest losses experienced by farmers, the federal government of Nigeria concessioned 17 silos with 6000 metric tonne storage space to private sector to enable farmers to have access to storage facilities. This paper discusses the causes, effects and solutions in handling post-harvest losses and optimize returns on food security in northeast Nigeria.

Keywords: farmers, food security, northeast Nigeria, postharvest loss

Procedia PDF Downloads 72

Authors: Ashvinie Thembiliyagoda, Kasun De Silva, Nimal Wijayaratna

Abstract:

The lowering of the riverbed level as a result of water erosion is termed as scouring. This phenomenon remarkably undermines the potential stability of the bridge pier, causing a threat of failure or collapse. The formation of vortices in the vicinity of bridges due to the obstruction caused by river flow is the main reason behind this pursuit. Scouring is aggravated by factors including high flow rates, bridge pier geometry, sediment configuration etc. Tackling scour-related problems when they become severe is more costly and disruptive compared to implementing preventive measures based on predicted scour depths. This paper presents a comprehensive investigation of the development of a numerical model that could reproduce the scouring effect around bridge piers and estimate the scour depth. The numerical model was developed for one selected bridge in Sri Lanka, the Kelanisiri Bridge. HEC-RAS two-dimensional (2D) modeling approach was utilized for the development of the model and was calibrated and validated with field data. To further enhance the reliability of the model, a physical model was developed, allowing for additional validation. Results from the numerical model were compared with those obtained from the physical model, revealing a strong correlation between the two methods and confirming the numerical model's accuracy in predicting scour depths. The findings from this study underscore the ability of the HEC-RAS two-dimensional modeling approach for the estimation of scour depth around bridge piers. The developed model is able to estimate the scour depth under varying flow conditions, and its flexibility allows it to be adapted for application to other bridges with similar hydraulic and geomorphological conditions, providing a robust tool for widespread use in scour estimation. The developed two-dimensional model not only offers reliable predictions for the case study bridge but also holds significant potential for broader implementation, contributing to the improved design and maintenance of bridge structures in diverse environments.

Keywords: piers, scouring, HEC-RAS, physical model

Procedia PDF Downloads 15

Authors: Abdul Nasir Zamir

Abstract:

After the downfall of Ottoman Caliphate, it scattered into different small Muslim states. Muslim leaders, intellectuals, revivalists as well as modernists started trying to boost up their nation. Some Muslims are also trying to establish the caliphate. Every Muslim country has its own political system, i.e., kingship, dictatorship or democracy, etc. But these are not in their original forms as the historian or political science discussed in their studies. The laws and their practice are mixed, i.e., others with Islamic laws, e.g., Saudi Arabia (K.S.A) and the Islamic Republic of Pakistan, etc. There is great conflict among the revivalist Muslim parties (groups) and governments about political systems. The question is that the subject matter is Sharia or political system? Leaders of Modern Muslim states are alleged as disbelievers due to neglecting the revelation in their laws and decisions. There are two types of laws; Islamic laws and management laws. The conflict is that the non-Islamic laws are in practice in Muslim states. Non-Islamic laws can be gradually changed with Islamic laws with a legal and peaceful process according to the practice of former Muslim leaders and scholars. The bloodshed of Muslims is not allowed in any case. Weak Muslim state is a blessing than nothing. The political system after Muhammad and guided caliphs is considered as kingship. But during this period Muslims not only developed in science and technology but conquered many territories also. If the original aim is in practice, then the Modern Muslim states can be stabled with different political systems. Modern Muslim states are the hope of survival, stability, and development of Muslim Ummah. Islam does not allow arm clash with Muslim army or Muslim civilians. The caliphate is based on believing in one Allah Almighty and good deeds according to Quran and Sunnah. As faith became weak and good deeds became less from its standard level, caliphate automatically became weak and even ended. The last weak caliphate was Ottoman Caliphate which was a hope of all the Muslims of the world. There is no caliphate or caliph present in the world. But every Muslim country or state is like an Amarat (a part of caliphate or small and alternate form of the caliphate) of Muslims. It is the duty of all Muslims to stable these modern Muslim states with tolerance.

Keywords: caliphate, conflict resolution, modern Muslim state, political conflicts, political systems, tolerance

Procedia PDF Downloads 155

Authors: Celeste Lawson

Abstract:

Learning to embrace and value teamwork assessment at a university level is critical for students, as graduates enter a real-world working environment where teamwork is likely to occur virtually. Student disdain for teamwork exercises is an area often overlooked or disregarded by academics. This research explored the implementation of an online teamwork assessment approach at a regional Australian university with a significant cohort of Distance Education students. Students had disliked teamwork for three reasons: it was not relevant to their study, the grading was unfair amongst team members, and managing the task was challenging in a virtual environment. Teamwork assessment was modified so that the task was an authentic task that could occur in real-world practice; team selection was based on the task topic rather than randomly; grading was based on the individual’s contribution to the task, and students were provided virtual team management skills as part of a the assessment. In this way, management of the team became an output of the task itself. Data was gathered over three years from student satisfaction surveys, failure rates, attrition figures, and unsolicited student comments. In one unit where this approach was adopted (Advanced Public Relations), student satisfaction increased from 3.6 (out of 5) in 2012 to 4.6 in 2016, with positive comments made about the teamwork approach. The attrition rate for another unit (Public Relations and the Media) reduced from 20.7% in 2012 to 2.2% in 2015. In 2012, criticism of teamwork assessment made up 50% of negative student feedback in Public Relations and the Media. By 2015, following the successful implementation of the teamwork assessment approach, only 12.5% of negative comments on the student satisfaction survey were critical of teamwork, while 33% of positive comments related to a positive teamwork experience. In 2016, students explicitly nominated teamwork as the best part of this unit. The approach is transferable to other disciplines and was adopted by other academics within the institution with similar results.

Keywords: assessment, distance education, teamwork, virtual

Procedia PDF Downloads 140

Authors: Mohammad Mirwais Yusufi

Abstract:

Skillful management is one of the most important success factors for today’s farms. When a farm is well managed, it can generate funds for its sustainability. Grape is one of the most diffused fruits in the world and one of the most important cash crops with high potential of production in Afghanistan as well. While there are several organizations intervening for improvement of this cash crop, the quality and quantity are still not satisfactory for producers and external markets. The situation has not changed over the years. Therefore, a survey was conducted in 2017 with 60 grape growers, supported by questionnaires in Mirbachakot, Kalakan and Shakardara districts of Kabul province. The purpose was to get an understanding of the current socio-demographic characteristics of farmers, management methods, constraints, farm size, yield and contribution of grape farming to household income. Findings indicate that grape farming was predominant 83.3% male, 16.6% female and small-scale farmers were the main grape producers, 60% < 1 ha of land under grape production. Likewise, 50% had more than > 10 years and 33.3% between 1-5 years’ experience in grape farming. The high level of illiteracy and diseases had significant digit effect on growth, yield and quality of grapes. The results showed that vineyard management operations to protect grapes from mechanical damage are very poor or completely absent. Comparing developed countries, table grape is one of the fruits with the highest input of technology, while in developing countries the cost of labor is low but the purchase of the equipment is very high due to financial situation. Hence the low quality and quantity of grape are influenced by poor management methods, such as non-availability of experts and lack of technical guidance in the study site. Thereby, the study suggested that improved agricultural extension services and managerial skills could contribute to addressing the problems.

Keywords: constraints, effect, management, Kabul

Procedia PDF Downloads 112

Authors: Eva Kirzner

Abstract:

Based on outcome studies published over the past two decades, in 2018, the ACC/AHA published new guidelines for the management of hypercholesterolemia that incorporate the use of coronary artery calcium (CAC) scanning as a decision tool for ascertaining which patients may benefit from statin therapy. This use is based on the recognition that the absence of calcium on CAC scanning (i.e., a CAC score of zero) usually signifies the absence of significant atherosclerotic deposits in the coronary arteries. Specifically, in patients with a high risk for atherosclerotic cardiovascular disease (ASCVD), initiation of statin therapy is generally recommended to decrease ASCVD risk. However, among patients with intermediate ASCVD risk, the need for statin therapy is less certain. However, there is a need for new outcome studies that provide evidence that the management of hypercholesterolemia based on these new ACC/AHA recommendations is safe for patients. Based on a Pub-Med and Google Scholar literature search, four relevant population-based or patient-based cohort studies that studied the relationship between CAC scanning, risk assessment or mortality, and statin therapy that were published between 2017 and 2021 were identified (see references). In each of these studies, patients were assessed for their baseline risk for atherosclerotic cardiovascular disease (ASCVD) using the Pooled Cohorts Equation (PCE), an ACC/AHA calculator for determining patient risk based on assessment of patient age, gender, ethnicity, and coronary artery disease risk factors. The combined findings of these four studies provided concordant evidence that a zero CAC score defines patients who remain at low clinical risk despite the non-use of statin therapy. Thus, these new studies confirm the use of CAC scanning as a safe tool for reducing the potential overuse of statin therapy among patients with zero CAC scores. Incorporating these new data suggest the following best practice: (1) ascertain ASCVD risk according to the PCE in all patients; (2) following an initial attempt trial to lower ASCVD risk with optimal diet among patients with elevated ASCVD risk, initiate statin therapy for patients who have a high ASCVD risk score; (3) if the ASCVD score is intermediate, refer patients for CAC scanning; and (4) and if the CAC score is zero among the intermediate risk ASCVD patients, statin therapy can be safely withheld despite the presence of an elevated serum cholesterol level.

Keywords: cholesterol, cardiovascular disease, statin therapy, coronary calcium

Procedia PDF Downloads 115

Authors: K. Sushma Varma, Rajesh Singh

Abstract:

Non-engineered landfills cause serious environmental damage due to toxic emissions and mobilization of persistent pollutants, organic and inorganic contaminants, as well as soluble metal ions. The available treatment technologies for landfill leachate and solid waste are not effective from an economic, environmental, and social standpoint. The present study assesses the potential of the bioelectrochemical system (BES) integrated with sulfate-reducing bacteria (SRB) in the sustainable treatment and decontamination of landfill wastes. For this purpose, solid waste and landfill leachate collected from different landfill sites were evaluated for long-term treatment using the integrated SRB-BES anaerobic designed bioreactors after pre-treatment. Based on periodic gas composition analysis, physicochemical characterization of the leachate and solid waste, and metal concentration determination, the present system demonstrated significant improvement in volumetric hydrogen production by suppressing methanogenesis. High reduction percentages of Be, Cr, Pb, Cd, Sb, Ni, Cr, COD, and sTOC removal were observed. This mineralization can be attributed to the synergistic effect of ammonia-assisted pre-treatment complexation and microbial sulphide formation. Despite being amended with 0.1N ammonia, the treated leachate level of NO³⁻ was found to be reduced along with SO₄²⁻. This integrated SRB-BES system can be recommended as an eco-friendly solution for landfill reclamation. The BES-treated solid waste was evidently more stabilized, as shown by a five-fold increase in surface area, and potentially useful for leachate immobilization and bio-fortification of agricultural fields. The vector arrangement and magnitude showed similar treatment with differences in magnitudes for both leachate and solid waste. These findings support the efficacy of SRB-BES in the treatment of landfill leachate and solid waste sustainably, inching a step closer to our sustainable development goals. It utilizes low-cost treatment, and anaerobic SRB adapted to landfill sites. This technology may prove to be a sustainable treatment strategy upon scaling up as its outcomes are two-pronged: landfill waste treatment and energy recovery.

Keywords: bio-electrochemical system, leachate /solid waste treatment, landfill leachate, sulfate-reducing bacteria

Procedia PDF Downloads 102

Authors: Akm Shahidullah

Abstract:

This paper assessed the medicinal plants production and related entrepreneurial and management aspects with a focus to understand the present medicinal plants-based supply chain of Bangladesh. It delineated the overall supply chain and the extent of benefit that the plant-producingagrientrepreneursderive out of the existing system of the chain. The key objective was to put forward innovative supply chain strategiesthatcan leverage the benefit of the rural farmer-entrepreneur of medicinal plants. A field-based investigation was carried out in the Natore district of northwest Bangladesh, where a total of 225 farmers and households from eight villages were engaged in the production of medicinal plant species. The research had a survey with the agrientrepreneurs of two of those villages and focus group discussions at a union level to gather information about the price, buyers, seasonality, and overall supply infrastructure and trading mechanisms of the plant products. The research also gathered explanations on the overall supply chain system of the plants and plant-based processed products through key informant interviews with the local and regional selling agents, stockists, wholesalers, and secondary processors. The findings revealed that, in the existing supply chain system, the primary and wholesale secondary markets were mostly dominated by middlemen who cause market distortions and inflated prices due to a lack of coordination between the primary producers and secondary processors. The discoordination and inefficiencies in the supply chain system could be offset by the producer-processor relationship integration that could result in a multitude of benefits to both the parties in terms of price, quality, lead time, and overall control of the supply chain. Therefore, to ensure the growth of medicinal plants production, the industry users, secondary processors, and policy stakeholders should ensure that the primary producers get the fair share of the benefit; the producer-processor relationship integration in the supply chain offers to ensure that fairness with maximum producer surplus.

Keywords: medicinal-plants, agrientrepreneur, supply chain, relationship integration, Bangladesh

Procedia PDF Downloads 93

Authors: Abdelkrim Khadir, Sina Kavalakatt, Preethi Cherian, Ali Tiss

Abstract:

Soluble epoxide hydrolase (sEH) is an emerging therapeutic target in several chronic states that have inflammation as a common underlying cause such as immunometabolic diseases. Indeed, sEH is known to play a pro-inflammatory role by metabolizing anti-inflammatory, epoxyeicosatrienoic acids (EETs) to pro-inflammatory diols. Recently, it was shown sEH to be linked to diet and microbiota interaction in rat models of obesity. Nevertheless, the functional contribution of sEH and its anti-inflammatory substrates EETs in obesity remain poorly understood. In the current study, we compared the expression pattern of sEH between lean and obese nondiabetic human subjects using subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs). Using RT-PCR, western blot and immunofluorescence confocal microscopy, we show here that the level of sEH mRNA and protein to be significantly increased in obese subjects with concomitant increase in endoplasmic reticulum (ER) stress components (GRP78 and ATF6α) and inflammatory markers (TNF-α, IL-6) when compared to lean controls. The observation that sEH was overexpressed in obese subjects’ prompt us to investigate whether physical exercise could reduce its expression. In this study, we report here 3-months supervised physical exercise significantly attenuated the expression of sEH in both the SAT and PBMCs, with a parallel decrease in the expression of ER stress markers along with attenuated inflammatory response. On the other hand, homocysteine, a sulfur containing amino acid deriving from the essential amino acid methionine was shown to be directly associated with insulin resistance. When 3T3-L1 preadipocytes cells were treated with homocysteine our results show increased sEH levels along with ER stress markers. Collectively, our data suggest that sEH upregulation is strongly linked to ER stress in adiposity and that physical exercise modulates its expression. This gives further evidence that exercise might be useful as a strategy for managing obesity and preventing its associated complications.

Keywords: obesity, adipose tissue, epoxide hydrolase, ER stress

Procedia PDF Downloads 139

Authors: Marko Spasojevic, Ying Hei Chui, Yuxiang Chen

Abstract:

Increasing the level of exterior insulation in residential buildings is a popular way for improving the thermal characteristic of building enclosure and reducing heat loss. However, the layout and properties of materials composing the wall have a great effect on moisture accumulation within the wall cavity, long-term durability of a wall as well as the structural performance. A one-dimensional hygrothermal modeling has been performed to investigate moisture condensation risks and the drying capacity of standard 2×4 and 2×6 light wood-frame wall assemblies including exterior low-permeance extruded polystyrene (XPS) insulation. The analysis considered two different wall configurations whereby the rigid insulation board was placed either between Oriented Strand Board (OSB) sheathing and the stud or outboard to the structural sheathing. The thickness of the insulation varied between 0 mm and 50 mm and the analysis has been conducted for eight different locations in Canada, covering climate zone 4 through zone 8. Results show that the wall configuration with low-permeance insulation inserted between the stud and OSB sheathing accumulates more moisture within the stud cavity, compared to the assembly with the same insulation placed exterior to the sheathing. On the other hand, OSB moisture contents of the latter configuration were markedly higher. Consequently, the analysis of hygrothermal performance investigated and compared moisture accumulation in both the OSB and stud cavity. To investigate the structural performance of the wall and the effect of soft insulation layer inserted between the sheathing and framing, forty nail connection specimens were tested. Results have shown that both the connection strength and stiffness experience a significant reduction as the insulation thickness increases. These results will be compared with results from a full-scale shear wall tests in order to investigate if the capacity of shear walls with insulated sheathing would experience a similar reduction in structural capacities.

Keywords: hygrothermal analysis, insulated sheathing, moisture performance, nail joints, wood shear wall

Procedia PDF Downloads 128

Authors: Lancelot Boulet, Pierre Benard, Ghislain Lartigue, Vincent Moureau, Nicolas Chauvet, Sheddia Didorally

Abstract:

International aeronautic standards demand a fire certification for engines that demonstrate their resistance. This demonstration relies on tests performed with prototype engines in the late stages of the development. Hardest tests require to place a kerosene standardized flame in front of the engine casing during a given time with imposed temperature and heat flux. The purpose of this work is to provide a better characterization of a kerosene/air certification burner in order to minimize the risks of test failure. A first Large-Eddy Simulation (LES) study of the certification burner permitted to model and simulate this burner, including both adiabatic and Conjugate Heat Transfer (CHT) computations. Carried out on unstructured grids with 40 million tetrahedral cells, using the finite-volume YALES2 code, spray combustion, forced convection on walls and conduction in the solid parts of the burner were coupled to achieve a detailed description of heat transfer. It highlighted the fact that conduction inside the solid has a real impact on the flame topology and the combustion regime. However, in the absence of radiative heat transfer, unrealistic temperature of the equipment was obtained. The aim of the present study is to include the radiative heat transfer in order to reach the same temperature given by experimental measurements. First, various test-cases are conducted to validate the coupling between the different heat solvers. Then, adiabatic case, CHT case, as well as CHT including radiative transfer are studied and compared. The LES model is finally applied to investigate the heat transfer in a flame impaction configuration. The aim is to progress on fire test modeling so as to reach a good confidence level as far as success of the certification test is concerned.

Keywords: conjugate heat transfer, fire resistance test, large-eddy simulation, radiative transfer, turbulent combustion

Procedia PDF Downloads 223

Authors: Hatice Idil Gorgen

Abstract:

Turkey has been investing in its national defence industrial base since the 1980s. State’s role in defence industry showed differences in Turkey. Parallel with this, ruling group’s attitude toward companies in defence sector varied. These changes in policies and behaviors of the state have occurred throughout such milestones as political and economic turmoil in domestic and international level. Hence, it is argued that state’s role, relations with private companies in defense sector and its policies towards the defense industry has shown differences due to the international system, political institutions, ideas and political coalitions in Turkey since the 1980s. Therefore, in order to see changes in the role of the state in defence sector, this paper aims to indicate first, history of state’s role in production and defence industry in the post-1980s era. Secondly, to comprehend the changes in the state’s role in defence industry, Stephan Haggard’s sources of policy change will be provided in the theoretical ground. Thirdly, state cooperated, and joint venture defence firms, state’s actions toward them will be observed. The remaining part will explore the underlying reasons for the changes in the role of the state in defence industry, and it implicitly or explicitly impacts on state business relations. Major findings illustrate that targeted idea of self-sufficient or autarky Turkey to attract domestic audience and to raise the prestige through defence system; ruling elites can regard defence industry and involved business groups as a mean for their ends. State dominant value, sensitive perception which has been ever since Ottoman Empire, prioritizes business groups in defence industry compared to others and push the ruling elites to pursue hard power in defence sectors. Through the globally structural transformation in defence industry, integration of Turkey to liberal bloc deepened and widened interdependence among states. Although it is a qualitative study, it involves the numerated data and descriptive statistics. Data will be collected by searching secondary sources from the literature, examining official documents of ministry of defence, and other appropriate ministries.

Keywords: defense industry, state and business relations, public private relations, arm industry

Procedia PDF Downloads 315

Authors: Mikael Soini, Kari Björn

Abstract:

Metropolia University of Applied Sciences (MUAS) Information and Communication Technology (ICT) Degree Programme provides full-time Bachelor-level undergraduate studies. ICT Degree Programme has seven different major options; this paper focuses on Health Technology. In Health Technology, a significant curriculum change in 2014 enabled transition from fragmented curriculum including dozens of courses to a new integrated curriculum built around three 30 ECTS themes. This paper focuses especially on the second theme called Customer Oriented Software Applications. From students’ point of view, the goal of this theme is to get familiar with existing health related ICT solutions and systems, understand business around health technology, recognize social and healthcare operating principles and services, and identify customers and users and their special needs and perspectives. This also acts as a background for health related web application development. Built web application is tested, developed and evaluated with real users utilizing versatile user centred development methods. This paper presents experiences obtained from the first implementation of Customer Oriented Software Applications theme. Student feedback was gathered with two questionnaires, one in the middle of the theme and other at the end of the theme. Questionnaires had qualitative and quantitative parts. Similar questionnaire was implemented in the first theme; this paper evaluates how the theme-based integrated curriculum has progressed in Health Technology major by comparing results between theme 1 and 2. In general, students were satisfied for the implementation, timing and synchronization of the courses, and the amount of work. However there is still room for development. Student feedback and teachers’ observations have been and will be used to develop the content and operating principles of the themes and whole curriculum.

Keywords: engineering education, integrated curriculum, learning and teaching methods, learning experience

Procedia PDF Downloads 321

Authors: Abanda Wilfred Chick

Abstract:

Background: According to World Health Organization (WHO), the role of Information and Communication Technologies (ICT) in health sectors of developing nations has been demonstrated to have had a great improvement of fifty percent reduction in mortality and or twenty-five-fifty percent increase in productivity. The objective of this study was to assess the use of information and communication technologies in enhancing health care delivery for Human Immunodeficiency Virus (HIV) patients in Bamenda Health District. Methods: This was a descriptive-analytical cross-sectional study in which 388 participants were consecutively selected amongst health personnel and HIV patients from public and private health institutions involved in Human Immunodeficiency Virus management. Data on socio-demographic variables, the use of information and communication technologies tools, and associated challenges were collected using structured questionnaires. Descriptive statistics with a ninety-five percent confidence interval were used to summarize findings, while Cramer’s V test, logistic regression, and Chi-square test were used to measure the association between variables, Epi info version7.2, MS Excel, and SPSS version 25.0 were utilized for data entry and statistical analysis respectively. Results: Of the participants, one-quarter were health personnel, and three-quarters were HIV patients. For both groups of participants, there was a significant relationship between the use of ICT and demographic information such as level of education, marital status, and age (p<0.05). For the impediments to using ICT tools, a greater proportion identified the high cost of airtime or internet bundles, followed by an average proportion that indicated inadequate training on ICT tools; for health personnel, the majority said inadequate training on ICT tools/applications and half said unavailability of electricity. Conclusion: Not up to half of the HIV patients effectively make use of ICT tools/applications to receive health care. Of health personnel, three quarters use ICTs, and only one quarter effectively use mobile phones and one-third of computers, respectively, to render care to HIV patients.

Keywords: ICT tools, HIV patients, health personnel, health care delivery

Procedia PDF Downloads 84

Authors: Camellia Al-Ibrahim, Jenny Yiend, Sukhwinder S. Shergill

Abstract:

Background: Attention bias to threat play a role in the development, maintenance, and exacerbation of delusional beliefs in schizophrenia in which patients emphasize the threatening characteristics of stimuli and prioritise them for processing. Cognitive control deficits arise when task-irrelevant emotional information elicits attentional bias and obstruct optimal performance. This study is investigating neural correlates of interference effect of linguistic threat and whether these effects are independent of delusional severity. Methods: Using an event-related functional magnetic resonance imaging (fMRI), neural correlates of interference effect of linguistic threat during the emotional Stroop task were investigated and compared patients with schizophrenia with high (N=17) and low (N=16) paranoid symptoms and healthy controls (N=20). Participants were instructed to identify the font colour of each word presented on the screen as quickly and accurately as possible. Stimuli types vary between threat-relevant, positive and neutral words. Results: Group differences in whole brain effects indicate decreased amygdala activity in patients with high paranoid symptoms compared with low paranoid patients and healthy controls. Regions of interest analysis (ROI) validated our results within the amygdala and investigated changes within the striatum showing a pattern of reduced activation within the clinical group compared to healthy controls. Delusional severity was associated with significant decreased neural activity in the striatum within the clinical group. Conclusion: Our findings suggest that the emotional interference mediated by the amygdala and striatum may reduce responsiveness to threat-related stimuli in schizophrenia and that attenuation of fMRI Blood-oxygen-level dependent (BOLD) signal within these areas might be influenced by the severity of delusional symptoms.

Keywords: attention bias, fMRI, Schizophrenia, Stroop

Procedia PDF Downloads 200

Authors: Kingston Rajiah, Mari Kannan Maharajan, Si Jen Yeen, Sara Lew

Abstract:

Parkinson’s disease (PD) is a progressive neurodegenerative disorder with evolving layers of complexity. Both motor and non-motor symptoms of PD may affect patients’ quality of life (QoL). Life expectancy for an individual with Parkinson’s disease depends on the level of care the individual has access to, can have a direct impact on length of life. Therefore, improvement of the QoL is a significant part of therapeutic plans. Patients with PD, especially those who are in advanced stages, are in great need of assistance, mostly from their family members or caregivers in terms of medical, emotional, and social support. The role of a caregiver becomes increasingly important with the progression of PD, the severity of motor impairment and increasing age of the patient. The nature and symptoms associated with PD can place significant stresses on the caregivers’ burden. As the prevalence of PD is estimated to more than double by 2030, it is important to recognize and alleviate the burden experienced by caregivers. This study focused on the impact of the clinical features on the QoL of PD patients, and of their caregivers. This study included PD patients along with their caregivers and was undertaken at the Malaysian Parkinson's Disease Association from June 2016 to November 2016. Clinical features of PD patients were assessed using the Movement Disorder Society revised Unified Parkinson Disease Rating Scale (MDS-UPDRS); the Hoehn and Yahr Staging of Parkinson's Disease were used to assess the severity and Parkinson's disease activities of daily living scale were used to assess the disability of Parkinson’s disease patients. QoL of PD patients was measured using the Parkinson's Disease Questionnaire-39 (PDQ-39). The revised version of the Zarit Burden Interview assessed caregiver burden. At least one of the clinical features affected PD patients’ QoL, and at least one of the QoL domains affected the caregivers’ burden. Clinical features ‘Saliva and Drooling’, and ‘Dyskinesia’ explained 29% of variance in QoL of PD patients. The QoL domains ‘stigma’, along with ‘emotional wellbeing’ explained 48.6% of variance in caregivers’ burden. Clinical features such as saliva, drooling and dyskinesia affected the QoL of PD patients. The PD patients’ QoL domains such as ‘stigma’ and ‘emotional well-being’ influenced their caregivers’ burden.

Keywords: carers, quality of life, clinical features, Malaysia

Procedia PDF Downloads 244

Authors: Hassan Abbas, Rehmat Ali, Muhammad Akbar

Abstract:

This study has been conducted in Sassi-Haramosh conservancy District Gilgit, Gilgit-Baltistan of Pakistan, under the Conservation Leadership Programme of Fauna and Flora International. The main objectives of the study were to assess the socio-economic impact of community-based conservation in Sassi-Haramosh conservancy and identify effects of trophy hunting on the conservation of wildlife in the area. The first trophy hunting program of Astor Markhor was held in year February 21, 2015, and the second on February 21, 2016. The community received a share of 49200 USD and 52400 USD from the first and second hunting, and the total earning was 101600 USD which are Rs. 10,871,200 in Pak Rs. The amounts from the trophy hunting are being managed by the Wildlife Conservation and Social Development Organization (WCSDO) Sassi. The village-based organization WCSDO is spending 50% of the trophy hunting amount in the protection of wildlife, its habitat and other natural resources, 30% in developmental sectors of the village and 20% of the amount in the office expenses. Several developmental projects, like construction of 300 KVA hydropower stations, purchase of 8 acres of land for agriculture, potable water supply project, construction of treks, and other social welfare activities have been carried in the village utilizing the trophy hunting grant. These developmental activities have uplifted the socio-economic conditions of the conservancy. Furthermore, trophy hunting program has positive impacts on the wildlife in the area, as the population of Markhor and Ibex has been increased, results in increasing number of other carnivores in the area. The WCSDO has banned any illegal activities in the habitat of wildlife and grazing of livestock in the core habitats. The program raised the level of awareness in communities and reduced poaching, illegal hunting, cutting of shrubs and extraction of Artemisia species from the pastures.

Keywords: Markhor, trophy hunting, Sassi-Haramosh, Gilgit

Procedia PDF Downloads 257

Authors: Amirreza Fazely Hamedani, Muzzamil Aziz, Philipp Wieder, Ramin Yahyapour

Abstract:

Software-defined networking in recent years came into the sight of so many network designers as a successor to the traditional networking. Unlike traditional networks where control and data planes engage together within a single device in the network infrastructure such as switches and routers, the two planes are kept separated in software-defined networks (SDNs). All critical decisions about packet routing are made on the network controller, and the data level devices forward the packets based on these decisions. This type of network is vulnerable to DDoS attacks, degrading the overall functioning and performance of the network by continuously injecting the fake flows into it. This increases substantial burden on the controller side, and the result ultimately leads to the inaccessibility of the controller and the lack of network service to the legitimate users. Thus, the protection of this novel network architecture against denial of service attacks is essential. In the world of cybersecurity, attacks and new threats emerge every day. It is essential to have tools capable of managing and analyzing all this new information to detect possible attacks in real-time. These tools should provide a comprehensive solution to automatically detect, predict and prevent abnormalities in the network. Big data encompasses a wide range of studies, but it mainly refers to the massive amounts of structured and unstructured data that organizations deal with on a regular basis. On the other hand, it regards not only the volume of the data; but also that how data-driven information can be used to enhance decision-making processes, security, and the overall efficiency of a business. This paper presents an intelligent big data framework as a solution to handle illegitimate traffic burden on the SDN network created by the numerous DDoS attacks. The framework entails an efficient defence and monitoring mechanism against DDoS attacks by employing the state of the art machine learning techniques.

Keywords: apache spark, apache kafka, big data, DDoS attack, machine learning, SDN network

Procedia PDF Downloads 169

Authors: Chen ChihYu, Tang Wen Tzu, Chen Kuang Hui

Abstract:

Aim —To compare the dismount skill between Taiwanese and elite international gymnastics in parallel bars following the 2017-2020 code of points. Methods—The gymnasts who advanced to the parallel bars event finals of these four competitions including World Championships, Universiade, the National Games of Taiwan, and the National Intercollegiate Athletic Games of Taiwan both 2017 and 2019 were selected in this study. The dismount skill of parallel bars was analyzed, and the average difficulty score was compared by one-way ANOVA. Descriptive statistics were applied to present the type of dismount skill and the difficulty of each gymnast in these four competitions. The data from World Championships and Universiade were combined as the international group (INT), and data of Taiwanese National Games and National Intercollegiate Athletic Games were also combined as the national group (NAT). The differences between INT and NAT were analyzed by the Chi-square test. The statistical significance of this study was set at α= 0.05. Results— i) There was a significant difference in the mean parallel bars dismount skill in these four competitions analyzed by one-way ANOVA. Both dismount scores of World Championships and Universiade were significantly higher than in Taiwanese National Games and National Intercollegiate Athletic Games (0.58±0.08 & 0.56±0.08 > 0.42±0.06 & 40±0.06, p < 0.05). ii) Most of the gymnasts in World Championships and Universiade selected the 0.6-point skill as the parallel bars dismount element, and for the Taiwanese National Games and the National Intercollegiate Athletic Games, most of the gymnasts performed the 0.4-point dismount skill. iii) The result of the Chi-square test has shown that there was a significant difference in the selection of parallel bars dismount skill. The INT group used the E or E+ difficulty element as the dismount skill, and the NAT group selected the D or D- difficulty element. Conclusion— The level of parallel bars dismount in Taiwanese gymnastics is inferior to elite international gymnastics. It is suggested that Taiwanese gymnastics must try to practice the F difficulty dismount (double salto forward tucked with half twist) in the future.

Keywords: Artistic Gymnastics World Championships, dismount, difficulty score, element

Procedia PDF Downloads 142

Authors: Akram Abi, Clarissa Müller, Hans-Joachim Jördening

Abstract:

Laminaribiose is a beta-1,3-glycoside which is used in the medical field for the treatment of dermatitis and also can be used as a building block for new pharmaceutics. The conventional process of laminaribiose production is the uneconomical process of hydrolysis of laminarin extracted from natural polysaccharides of plant origin. A more economical approach however is attainable by enzymatically synthesis of laminaribiose via a reverse phosphorylase reaction catalyzed by laminaribiose phosphorylase (LP) from Euglena gracilis. Different cultivation methods of Euglena gracilis and the effect on LP production have been investigated. Buffered/unbuffered heterotrophic and mixotrophic cultivations of Euglena gracilis has been carried out. Changes of biomass and LP production, glucose level and pH, cell count and shape has been monitored in the course of time. The results obtained from experiments each in three repetitions, show that in the heterotrophic cultivation of Euglena gracilis not only more biomass is produced compared to mixotrophic cultivation, but also higher specific protein concentration is achieved. Furthermore, the LP activity test showed that the protein extracted from heterotrophically cultured cells has a higher LP activity. It was also observed that the cells develop in a distinctive different shape between these two cultures and have different length to width ratios. Taking the heterotrophic culture as the more efficient cultivation method in LP production, another comparative experiment between buffered and unbuffered heterothrophic culture was carried out that showed the unbuffered culture has advantages over the other one in respect of both LP production and resulting activity. A hetrotrophic cultivation of Euglena gracilis in a 5L bioreactor with controlled operating conditions showed a distinctive improvement of all the aspects of culture compared to the shaking flask cultivations. Biomass production was improved from 5 to more than 8 g/l (dry weight) which resulted in a specific protein concentration of 45 g/l in the heterotrophic cultivation in the bioreactor. In further attempts to improve LP production, different purification methods were tested and each method was checks through an activity assay. A laminaribiose yield of 35% was achieved which was by far the highest amount amongst different methods tested.

Keywords: euglena gracilis, heterotrophic culture, laminaribiose production, mixotrophic culture

Procedia PDF Downloads 365

Authors: Dong Tang, Yongli Zhao

Abstract:

The study of the microstructure of asphalt is of great importance for the analysis of its macroscopic properties. However, the peculiarities of the chemical composition of the asphalt itself and the limitations of existing direct imaging techniques have caused researchers to face many obstacles in studying the microstructure of asphalt. The advantage of small-angle X-ray scattering (SAXS) is that it allows quantitative determination of the internal structure of opaque materials and is suitable for analyzing the microstructure of materials. Therefore, the SAXS technique was used to study the evolution of microstructures on the nanoscale during asphalt aging. And the reasons for the change in scattering contrast during asphalt aging were also explained with the help of Fourier transform infrared spectroscopy (FTIR). SAXS experimental results show that the SAXS curves of asphalt are similar to the scattering curves of scattering objects with two-level structures. The Porod curve for asphalt shows that there is no obvious interface between the micelles and the surrounding mediums, and there is only a fluctuation of the hot electron density between the two. The Beaucage model fit SAXS patterns shows that the scattering coefficient P of the asphaltene clusters as well as the size of the micelles, gradually increase with the aging of the asphalt. Furthermore, aggregation exists between the micelles of asphalt and becomes more pronounced with increasing aging. During asphalt aging, the electron density difference between the micelles and the surrounding mediums gradually increases, leading to an increase in the scattering contrast of the asphalt. Under long-term aging conditions due to the gradual transition from maltenes to asphaltenes, the electron density difference between the micelles and the surrounding mediums decreases, resulting in a decrease in the scattering contrast of asphalt SAXS. Finally, this paper correlates the macroscopic properties of asphalt with microstructural parameters, and the results show that the high-temperature rutting resistance of asphalt is enhanced and the low-temperature cracking resistance decreases due to the aggregation of micelles and the generation of new micelles. These results are useful for understanding the relationship between changes in microstructure and changes in properties during asphalt aging and provide theoretical guidance for the regeneration of aged asphalt.

Keywords: asphalt, Beaucage model, microstructure, SAXS

Procedia PDF Downloads 80

Authors: Maha Ben Salem

Abstract:

The transformative aspect of emerging adulthood brings about a development of self-processes, including changes in self-esteem and personal goals. Success in this life stage entails the emotional growth necessary to navigate the demands and challenges of college life. Understanding the concept of self-awareness within this particular age group sheds light on emerging adults’ internal world and the transformative aspect of their emotional growth. Uncovering the thoughts' processes that foster or hinder self-awareness is important to the understanding of how emerging adults learn to make themselves positive or negative. However, existing research in self-awareness has explored this phenomenon mostly using quantitative research methodology or through tying an individual’s level of self-awareness to specific actions or outcomes. Little is known about the process of how college students emerging adults notice and monitor their inner thoughts and emotions. Methodology and theoretical orientation: A grounded theory study using in-depth semi-structured interview was utilized. Nine interviews have been conducted. A constructionist framework was employed to generate a theory as for how self-awareness facilitates specific patterns of thinking in emerging adults. The choice of grounded theory emanates from a lack of knowledge regarding underlying thinking procedures and internal states that emerging adult college students navigate in an attempt to make meaning out of the new academic experience and life stage. Findings: Initial data analysis generated the following categories of the theory: (a) a non-judgmental perception of negative thinking and negative emotions that allow for a better understanding of the self; (b) negative state of mind is easy to overcome when it is accepted and acknowledged; (c) knowledge of the actual and desired self-generates an intentional decision to shift to a positive mindset. Preliminary findings indicate that college academic and social environment foster a new understanding of the self that yield a change in mindset and in self-knowledge.

Keywords: college environment, emergent adults, grounded theory, positive mindset, self-awareness

Procedia PDF Downloads 133