Search results for: natural and anthropogenic safety

Authors: Seung-Min Ko, Seung-Jai Choi, Gun Jung, Jang-Ho Jay Kim

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Although extensive explosion-related research has been performed in the past several decades, almost no research has focused on internal blasts. However, internal blast research is needed to understand about the behavior of a containment structure or building under internal blast loading, as in the case of the Chornobyl and Fukushima nuclear accidents. Therefore, the internal blast study concentrated on RC and PSC structures is performed. The test data obtained from reinforced concrete (RC) and prestressed concrete (PSC) tubular structures applied with an internal explosion using ammonium nitrate/fuel oil (ANFO) charge are used to assess their deformation resistance and ultimate failure load based on the structural stiffness change under various charge weight. For the internal blast charge weight, ANFO explosive charge weights of 15.88, 20.41, 22.68 and 24.95 kg were selected for the RC tubular structures, and 22.68, 24.95, 27.22, 29.48, and 31.75 kg were selected for PSC tubular structures, which were detonated at the center of cross section at the mid-span with a standoff distance of 1,000mm to the inner wall surface. Then, the test data were used to predict the internal charge weight required to fail a real scale reinforced concrete containment vessels (RCCV) and prestressed concrete containment vessel (PCCV). Then, the analytical results based on the experimental data were derived using the simple assumptions of the models, and another approach using the stiffness, deformation and explosion weight relationship was used to formulate a general method for analyzing internal blasted tubular structures. A model of the internal explosion of a steel tube was used as an example for validation. The proposed method can be used generically, using factors according to the material characteristics of the target structures. The results of the study are discussed in detail in the paper.

Keywords: internal blast, reinforced concrete, RCCV, PCCV, stiffness, blast safety

Procedia PDF Downloads 79

Authors: Alexander S. Burnasov, Anatoly V. Stepanov, Maria Y. Ilyushkina

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In the conditions of transition to the digital economy, the digital environment of the city becomes one of the key factors of its tourism attractiveness. Modern digital environment makes travelling more accessible, improves the quality of travel services and the attractiveness of many tourist destinations. The digitalization of the industry allows to use resources more efficiently, to simplify business processes, to minimize risks, and to improve travel safety. The city promotion as a tourist destination in the foreign market becomes decisive in the digital environment. Information technologies are extremely important for the functioning of not only any tourist enterprise but also the city as a whole. In addition to solving traditional problems, it is also possible to implement some innovations from the tourism industry, such as the availability of city services in international systems of booking tickets and booking rooms in hotels, the possibility of early booking of theater and museum tickets, the possibility of non-cash payment by cards of international payment systems, Internet access in the urban environment for travelers. The availability of the city's digital services makes it possible to reduce ordering costs, contributes to the optimal selection of tourist products that meet the requirements of the tourist, provides increased transparency of transactions. The users can compare prices, features, services, and reviews of the travel service. The ability to share impressions with friends thousands of miles away directly affects the image of the city. It is possible to promote the image of the city in the digital environment not only through world-scale events (such as World Cup 2018, international summits, etc.) but also through the creation and management of services in the digital environment aimed at supporting tourism services, which will help to improve the positioning of the city in the global tourism market.

Keywords: competitiveness, digital environment, travelling, Yekaterinburg

Procedia PDF Downloads 137

Authors: Mitchell Gohnert, Ryan Bradley

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This paper reviews some fundamental concepts of structural optimization, which are based on the type of materials used in construction and the shape of the structure. The first step in structural optimization is to break down all internal forces in a structure into fundamental stresses, which are tensions and compressions. Knowing the stress patterns directs our selection of structural shapes and the most appropriate type of construction material. In our selection of materials, it is essential to understand all construction materials have flaws, or micro-cracks, which reduce the capacity of the material, especially when subjected to tensions. Because of material defects, many construction materials perform significantly better when subjected to compressive forces. Structures are also more efficient if bending moments are eliminated. Bending stresses produce high peak stresses at each face of the member, and therefore, substantially more material is required to resist bending. The shape of the structure also has a profound effect on stress levels. Stress may be reduced dramatically by simply changing the shape. Catenary, triangular and linear shapes are the fundamental structural forms to achieve optimal stress flow. If the natural flow of stress matches the shape of the structures, the most optimal shape is determined.

Keywords: arches, economy of stresses, material strength, optimization, shells

Procedia PDF Downloads 116

Authors: Kushal Gowda Jayaram, Joseph Huret, Jonathan Quibel, Walter-John Chitty, Gilbert Henaff

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Thermal aging is one of the concerns for the long-term operation of nuclear power plants. Indeed, components in the primary circuit undergo thermal aging while exposed to the chemically active environment of Pressurized Water Reactors (PWRs) over time. Among the materials used in the reactor components, Alloy 690 can be found in some critical components for nuclear safety. Despite its importance, research on the effect of thermal aging on the microstructural changes and low cycle fatigue (LCF) behavior of Alloy 690 remains limited. This study aims to assess the impact of thermal aging on the fatigue life of Alloy 690. The as-received sample underwent aging at 420°C for 4000 hours, representing the equivalent aging of 60 years in reactor working conditions. First, the characterization of the area and density of intergranular and intragranular precipitates was performed to understand the microstructural changes in the aged specimen. Then, low cycle fatigue tests were conducted on the as received and aged samples at varying strain amplitudes. To investigate the influence of thermal aging on the fatigue behavior of Alloy 690, fracture surfaces were analyzed to estimate fatigue crack growth rates based on striation spacing measurements. Additionally, the axially cut fractured samples have undergone analysis using Electron Backscatter Diffraction (EBSD) to understand the effect of aging on strain localization near the crack path. Results indicate that while the characterization of the area and density of intergranular precipitates in the aged specimen (for 2000 hours, approximately 30 years) showed no significant changes, there was a slight increase in the area and density of intragranular precipitates under the same conditions.

Keywords: alloy 690, thermal aging, low cycle fatigue, precipitates

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Authors: Margareta Rahayuningsih, Nur Rahayu Utami, Tsabit A. M., Muh. Abdullah

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Mount Ungaran is one area that has remaining natural forest in Central Java, Indonesia. Mount Ungaran consists of several habitats that supporting appropriate areas for flora, fauna, and microorganisms biodiversity, particularly of it is protected by government law and IUCN red list data. Therefore, Mount Ungaran also settled up as AZE (Alliance for Zero Extinction) and IBA (Important Bird Area). The land use for agriculture and plantation reduces forest covered areas. It is serious threat to the existence of biodiversity in Moun Ungaran. This research has been identified community local wisdom that possible to be integrated as ethno-biological research and biodiversity conservation. The result showed at least four local wisdom that possible to be integrated to ethno-biological and biodiversity conservation were Wit Weh Woh (a ceremony of life-giving tree), Grebeg Alas Susuk Wangan (a ceremony for forest protection), Iriban (a ceremony of clean water resource protection), and tingkep tandur (a ceremony for ready-harvested plant protection). It is needed ethno-biological researches of local wisdom-contained values, which essential to be developed as a strategy for biodiversity conservation in Mount Ungaran.

Keywords: Mount Ungaran, local wisdom, biodiversity, fragmentation

Procedia PDF Downloads 283

Authors: O. Zimbili, W. Salim, M. Ndambuki

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Construction and Demolition (C&D) wastes contribute the highest percentage of wastes worldwide (75%). Furthermore, ceramic materials contribute the highest percentage of wastes within the C&D wastes (54%). The current option for disposal of ceramic wastes is landfill. This is due to unavailability of standards, avoidance of risk, lack of knowledge and experience in using ceramic wastes in construction. The ability of ceramic wastes to act as a pozzolanic material in the production of cement has been effectively explored. The results proved that temperatures used in the manufacturing of these tiles (about 900 ⁰C) are sufficient to activate pozzolanic properties of clay. They also showed that, after optimization (11-14% substitution), the cement blend performs better, with no morphological differences between the cement blended with ceramic waste, and that blended with other pozzolanic materials. Sanitary ware and electrical insulator porcelain wastes are some wastes investigated for usage as aggregates in concrete production. When optimized, both produced good results, better than when natural aggregates are used. However, the research on ceramic wastes as partial substitute for fine aggregates or cement has not been overly exploited as the other areas. This review has been concluded with focus on investigating whether ceramic wall tile wastes used as partial substitute for cement and fine aggregates could prove to be beneficial since the two materials are the most high-priced during concrete production.

Keywords: blended, morphological, pozzolanic, waste

Procedia PDF Downloads 367

Authors: Tania Tzong, Chao-Yi Teng, Tzong-Yuan Wu

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Currently, Chikungunya virus (CHIKV) transmitted to humans by Aedes mosquitoes has distributed from Africa to Southeast Asia, South America, and South Europe. However, little is known about the antigenic targets for immunity, and there are no licensed vaccines or specific antiviral treatments for the disease caused by CHIKV. Baculovirus has been recognized as a novel vaccine vector with attractive characteristic features of an optional vaccine delivery vehicle. This approach provides the safety and efficacy of CHIKV vaccine. In this study, bi-cistronic recombinant baculoviruses vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP were produced. Both recombinant baculovirus can express EGFP reporter gene in insect cells to facilitate the recombinant virus isolation and purification. Examination of vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP showed that this recombinant baculovirus could induce syncytium formation in insect cells. Unexpectedly, the immunofluorescence assay revealed the expression of E1 and E2 of CHIKV structural proteins in insect cells infected by vAc-CMV-CHIKV26S-Rhir-EGFP. This result may imply that the CMV promoter can induce the transcription of CHIKV26S in insect cells. There are also E1 and E2 expression in mammalian cells transduced by vAc-CMV-CHIKV26S-Rhir-EGFP and vAc-CMV-pH-CHIKV26S-Lir-EGFP. The expression of E1 and E2 proteins of insect and mammalian cells was validated again by Western blot analysis. The vector construction with dual tandem promoters, which is polyhedrin and CMV promoter, has higher expression of the E1 and E2 of CHIKV structural proteins than the vector construction with CMV promoter only. Most of the E1 and E2 proteins expressed in mammalian cells were glycosylated. In the future, the expression of structural proteins of CHIKV in mammalian cells is expected can form virus-like particle, so it could be used as a vaccine for chikungunya virus.

Keywords: chikungunya virus, virus-like particle, vaccines, baculovirus expression vector system

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Authors: Luma Vaz, Marcio Port-Carvalho

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The main objective of this research was to study the basics aspects of the ecology of a group of capuchin monkeys (Cebus spp.), evaluating the risks that habit and food that is given by the visitors may cause to the people's health and animals welfare, also how to make proposals for mitigation and management guidelines. In order to do that, some aspects of the animal's ecology (such as diet, habitat range and habitat use) and activity patterns were studied. It was also measured the frequency of contact with visitors at the park using protocols for data collection. The behavioral categories of displacement and resting represent more than 80% of total activities, followed by feeding (13%) and others (6%). When compared to the studies in natural environment, the Cebus group studied has a small living area (1.7ha) occupying mostly the PEAL public area. The diversity of items offered by the visitors and the high frequency of contact closer than one meter suggests that using information and education campaigns must be a priority in the public program in PEAL in order to avoid future accidents and diseases transmissions.

Keywords: capuchin monkeys, Cebus, environmental education, public health, wildlife management

Procedia PDF Downloads 142

Authors: Ana Fonseca, Ana Gouveia, Edgar Ramalho, Rita Henriques, Filipa Figueiredo, João Nunes

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Due to persistent climate pressures, there is a need to find a resilient economic system that is regenerative in nature. Bioeconomy offers the possibility of replacing non-renewable and non-biodegradable materials derived from fossil fuels with ones that are renewable and biodegradable, while a Circular Economy aims at sustainable and resource-efficient operations. The term "Circular Bioeconomy", which can be summarized as all activities that transform biomass for its use in various product streams, expresses the interaction between these two ideas. Portugal has a very favourable context to promote a Circular Bioeconomy due to its variety of climates and ecosystems, availability of biologically based resources, location, and geomorphology. Recently, there have been political and legislative efforts to develop the Portuguese Circular Bioeconomy. The Action Plan for a Sustainable Bioeconomy, approved in 2021, is composed of five axes of intervention, ranging from sustainable production and the use of regionally based biological resources to the development of a circular and sustainable bioindustry through research and innovation. However, as some statistics show, Portugal is still far from achieving circularity. According to Eurostat, Portugal has circularity rates of 2.8%, which is the second lowest among the member states of the European Union. Some challenges contribute to this scenario, including sectorial heterogeneity and fragmentation, prevalence of small producers, lack of attractiveness for younger generations, and absence of implementation of collaborative solutions amongst producers and along value chains.Regarding the Portuguese industrial sector, there is a tendency towards complex bureaucratic processes, which leads to economic and financial obstacles and an unclear national strategy. Together with the limited number of incentives the country has to offer to those that pretend to abandon the linear economic model, many entrepreneurs are hesitant to invest the capital needed to make their companies more circular. Absence of disaggregated, georeferenced, and reliable information regarding the actual availability of biological resources is also a major issue. Low literacy on bioeconomy among many of the sectoral agents and in society in general directly impacts the decisions of production and final consumption. The WinBio project seeks to outline a strategic approach for the management of weaknesses/opportunities in the technology transfer process, given the reality of the territory, through road mapping and national and international benchmarking. The developed work included the identification and analysis of agents in the interior region of Portugal, natural endogenous resources, products, and processes associated with potential development. Specific flow of biological wastes, possible value chains, and the potential for replacing critical raw materials with bio-based products was accessed, taking into consideration other countries with a matured bioeconomy. The study found food industry, agriculture, forestry, and fisheries generate huge amounts of waste streams, which in turn provide an opportunity for the establishment of local bio-industries powered by this biomass. The project identified biological resources with potential for replication and applicability in the Portuguese context. The richness of natural resources and potentials known in the interior region of Portugal is a major key to developing the Circular Economy and sustainability of the country.

Keywords: circular bioeconomy, interior region of portugal, regional development., public policy

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Authors: Jen Wang, Wei-Chia Hsu, Zih-Sin Wang, Ching-Ping Chu, Bo-Shiou Guo

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In the late 19th century, the Jinguashi ore deposit in northern Taiwan was discovered, and accompanied with flourishing mining activities. However, tons of contaminants including heavy metals, sulfur dioxide, and total petroleum hydrocarbons (TPH) were released to surroundings and caused environmental problems. Site T was one of copper smelter located on the coastal hill near Jinguashi ore deposit. In over ten years of operation, variety contaminants were emitted that it polluted the surrounding soil and groundwater quality. In order to exhaust fumes produced from smelting process, three stacks were built along the hill behind the factory. The sediment inside the stacks contains high concentration of heavy metals such as arsenic, lead, copper, etc. Moreover, soil around the discarded stacks suffered a serious contamination when deposition leached from the ruptures of stacks. Consequently, Site T (including the factory and its surroundings) was declared as a pollution remediation site that visiting the site and land-use activities on it are forbidden. However, the natural landscape and cultural attractions of Site T are spectacular that it attracts a lot of visitors annually. Moreover, land resources are extremely precious in Taiwan. In addition, Taiwan Environmental Protection Administration (EPA) is actively promoting the contaminated land revitalization policy. Therefore, this study took Site T as case study for brownfield revitalization planning to the limits of activate and remediate the natural resources. Land-use suitability analysis and risk mapping were applied in this study to make appropriate risk management measures and redevelopment plan for the site. In land-use suitability analysis, surrounding factors into consideration such as environmentally sensitive areas, biological resources, land use, contamination, culture, and landscapes were collected to assess the development of each area; health risk mapping was introduced to show the image of risk assessments results based on the site contamination investigation. According to land-use suitability analysis, the site was divided into four zones: priority area (for high-efficiency development), secondary area (for co-development with priority area), conditional area (for reusing existing building) and limited area (for Eco-tourism and education). According to the investigation, polychlorinated biphenyls (PCB), heavy metals and TPH were considered as target contaminants while oral, inhalation and dermal would be the major exposure pathways in health risk assessment. In accordance with health risk map, the highest risk was found in the southwest and eastern side. Based on the results, the development plan focused on zoning and land use. Site T was recommended be divides to public facility zone, public architectonic art zone, viewing zone, existing building preservation zone, historic building zone, and cultural landscape zone for various purpose. In addition, risk management measures including sustained remediation, extinguish exposure and administration management are applied to ensure particular places are suitable for visiting and protect the visitors’ health. The consolidated results are corroborated available by analyzing aspects of law, land acquired method, maintenance and management and public participation. Therefore, this study has a certain reference value to promote the contaminated land revitalization policy in Taiwan.

Keywords: brownfield revitalization, land-use suitability analysis, health risk map, risk management

Procedia PDF Downloads 184

Authors: Nadir Sidiqi

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Biodiversity conservation is humanity’s building block to sustain lives - ultimately allowing all living and nonliving creatures to interact in a balanced proportion. Humanity’s challenge in the 21st century is to maintain biodiversity without harming the natural habitat of plants, animals and beneficial microorganisms. There are many good reasons to consider why biodiversity is important to every nation around the world, especially for a nation like Afghanistan. One of the major values of biodiversity is its economic value: biodiversity provides goods and services to the Afghan nation directly through links and components such as the maintenance of traditional crops, medicine, fruits, animals, grazing, fuel, timber, harvesting, fishing, hunting and related supplies. Biodiversity is the variety of the living components, such as humans, plants, animals, and microorganisms, and nonliving components interaction, including air, water, sunlight, soil, humidity and environmental factors in an area. There are many ways of gauging the value of biodiversity. As an ecosystem, biodiversity includes such benefits as soil fertility, erosion control, crop pollination, crop rotation, and pest control. The conservation of biodiversity is crucial for these benefits, which would be impossible to replace. Biodiversity conservation also has heritage values; this wealth of genetic diversity provides backup to rural people living close together.

Keywords: Afghanistan, biodiversity, conservation, economy, environment

Procedia PDF Downloads 529

Authors: Olufemi Oyedele

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Building collapse (BC) in Nigeria is becoming a regular occurrence, each recording great casualties in the number of lives and materials lost. Building collapse is a situation where building which has been completed and occupied, completed but not occupied or under construction, collapses on its own due to action or inaction of man or due to natural event like earthquake, storm, flooding, tsunami or wildfire. It is different from building demolition. There are various causes of building collapse and each case requires expert judgment to decide the cause of its collapse. Rate of building collapse is a reflection of the level of organization and control of building activities and degree of sophistication of the construction professionals in a country. This study explored the use of case study by examining the causes of six (6) collapsed buildings (CB) across Nigeria. Samples of materials from the sites of the collapsed buildings were taken for testing and analysis, while critical observations were made at the sites to note the conditions of the ground (building base). The study found out that majority of the building collapses in Nigeria were due to poor workmanship, sub-standard building materials, followed by bad building base and poor design. The National Building Code 2006 is not effective due to lack of enforcement and the Physical Development Departments of states and Federal Capital Territory are just mere agents of corruption allowing all types of construction without building approvals.

Keywords: building collapse, concrete tests, differential settlement, integrity test, quality control

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Authors: Mohd Ritzman Abdul Karim, Zhaohui Huang

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A current focus in seismic engineering practice is the development of seismic design approach that focuses on the performance-based design. Performance-based design aims to design the structures to achieve specified performance based on the damage limit states. This damage limit is more restrictive limit than life safety and needs to be carefully estimated to avoid damage in piers due to failure in transverse reinforcement. In this paper, a different perspective of damage limit states has been explored by integrating two damage control material limit state, concrete and reinforcement by introduced parameters such as expected yield stress of transverse reinforcement where peak tension strain prior to bar buckling is introduced in a recent study. The different perspective of damage limit states with modified yield displacement and the modified plastic-hinge length is used in order to predict damage-control target displacement for reinforced concreate (RC) bridge pier. Three-dimensional (3D) finite element (FE) model has been developed for estimating damage target displacement to validate proposed damage limit states. The result from 3D FE analysis was validated with experimental study found in the literature. The validated model then was applied to predict the damage target displacement for RC bridge pier and to validate the proposed study. The tensile strain on reinforcement and compression on concrete were used to determine the predicted damage target displacement and compared with the proposed study. The result shows that the proposed damage limit states were efficient in predicting damage-control target displacement consistent with FE simulations.

Keywords: damage-control target displacement, damage limit states, reinforced concrete bridge pier, yield displacement

Procedia PDF Downloads 157

Authors: Safa’ Abdelkarim Hammad

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The electrical power system is one of the main parts of the nation's infrastructure, and the availability and cost of electricity are critical factors in industrial competitiveness and strategy. Restructuring of the electricity supply industries is a very complex exercise based on national energy strategies and policies, macroeconomic developments, and national conditions, and its application varies from country to country. Electricity regulation of natural monopolies is a challenging task. Regulators face the problem of providing appropriate incentives for improvement of efficiency. Incentive regulation is often considered as an efficient regulatory tool to handle the problem, and it is widely applied in several countries. However, the exact regulation methodologies differ from one country to another. Network quantitative reliability evaluation is an essential factor with regard to the quality of supply. The main factors used to judge the reliability of supply is measured by the number and duration of interruptions experienced by customers. Several indicators are used to evaluate reliability in distribution networks. This paper addresses the impact of incentive regulation and performance benchmarking in the field of electricity distribution in Jordan. The theory of efficiency measurement and the most common models; NCSQS and DEA models are presented.

Keywords: incentive regulations, reliability, restructuring, Tarrif

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Authors: Xuelian Qin

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Urban "organic renewal" based on the development of existing resources in high-density urban areas has become the mainstream of urban development in the new era. As an important stock resource of public space in high-density urban areas, promoting its value remodeling is an effective way to alleviate the shortage of public space resources. However, due to the lack of evaluation links in the process of underpass space renewal, a large number of underpass space resources have been left idle, facing the problems of low space conversion efficiency, lack of accuracy in development decision-making, and low adaptability of functional positioning to citizens' needs. Therefore, it is of great practical significance to construct the evaluation system of under-bridge space renewal potential and explore the renewal mode. In this paper, some of the under-bridge spaces in the main urban area of Chongqing are selected as the research object. Through the questionnaire interviews with the users of the built excellent space under the bridge, three types of six levels and twenty-two potential evaluation indexes of "objective demand factor, construction feasibility factor and construction suitability factor" are selected, including six levels of land resources, infrastructure, accessibility, safety, space quality and ecological environment. The analytical hierarchy process and expert scoring method are used to determine the index weight, construct the potential evaluation system of the space under the bridge in high-density urban areas of Chongqing, and explore the direction of renewal and utilization of its suitability. To provide feasible theoretical basis and scientific decision support for the use of under bridge space in the future.

Keywords: high density urban area, potential evaluation, space under bridge, updated using

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Authors: Vaishnavi Unde, Srikanth Mutnuri

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Today dye stuff sector is one of the major chemical industries in India. Indigo is a blue coloured dye used all over the world in large quantity. The indigo dye produced and used in textile industries is synthetic having toxic effect, thus there is an increase in interest for natural dyes owing to the environmental concerns. The present study focuses on the use of a strain Pandoraea sp. isolated from garage soil, for the production of indigo in fed batch bioreactor. A comparative study between single phase and two phase production was carried out in this work. The blue colour produced during the experiments was analyzed using, TLC, UV-visible spectrophotometer and FTIR technique. The blue pigment was found to be indigo. The production of bio-indigo was done in a single phase fermentor carrying medium and substrate indole in dissolved form and was found to produce maximum of 0.041 g/L of indigo. Whereas there was an increase in production of indigo to 0.068 g/L in a two phase, water-silicone oil system. In this study the advantage of using second phase as silicone oil has enhanced the indigo production, as the second phase made the substrate available to the bacteria by increasing the surface area as well as it helped to prevent the inhibition effect of the high concentration of substrate, indole. The effect of single and two phases on the growth of bacteria was also studied.

Keywords: dyes, fed batch reactor, indole, Indigo

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Authors: Ahmad Rabby

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The present study emphasizing the catch trends assessment of Gray eel catfish (Plotosus canius) that was scrutinized on the basis of monthly length frequency data collected from mangrove estuary, Bangladesh during January 2017 to December 2018. A total amount of 1298 specimens were collected to estimate the total length (TL) and weight (W) of P. canius ranged from 13.3 cm to 87.4 cm and 28 g to 5200 g, respectively. The length-weight relationship was W=0.006 L2.95 with R2=0.972 for both sexes. The von Bertalanffy growth function parameters were L∞=93.25 cm and K=0.28 yr-1, hypothetical age at zero length of t0=0.059 years and goodness of the fit of Rn=0.494. The growth performances indices for L∞ and W∞ were computed as Φ'=3.386 and Φ=1.84, respectively. The size at first sexual maturity was estimated in TL as 48.8 cm for pool sexes. The natural mortality was 0.51 yr-1 at average annual water surface temperature as 22 0C. The total instantaneous mortality was 1.24 yr-1 at CI95% of 0.105–1.42 (r2=0.986). While fishing mortality was 0.73 yr-1 and the current exploitation ratio as 0.59. The recruitment was continued throughout the year with one major peak during May-June was 17.20-17.96%. The Beverton-Holt yield per recruit model was analyzed by FiSAT-II, when tc was at 1.43 yr, the Fmax was estimated as 0.6 yr-1 and F0.1 was 0.33 yr-1. Current age at the first capture was approximately 0.6 year, however Fcurrent = 0.73 yr-1 which is beyond the F0.1 indicated that the current stock of P. canius of Bangladesh was overexploited.

Keywords: Plotosus canius, mangrove estuary, asymptotic length, FiSAT-II

Procedia PDF Downloads 151

Authors: Salwa M. Almomen, Mona A. Almaghrabi, Saja M. Alhabardi, Adel A. Alrwisan

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Background: Hepatotoxicity is a major reason for medication withdrawal from the markets. Unfortunately, serious adverse hepatic effects can occur after marketing with limited indicators during clinical development. Therefore, finding possible predictors for hepatotoxicity might guide the monitoring program of various stakeholders. Methods: We examined the clinical review documents for drugs approved in the US from 2011 to 2016 to evaluate their hepatic safety profile. Predictors: we assessed whether these medications meet Hy’s Law with hepatotoxicity grade ≥ 3, labeled hepatic adverse effects at approval, or accelerated approval status. Outcome: post-marketing regulatory action related to hepatotoxicity, including product withdrawal or updates to warning, precaution, or adverse effects sections. Statistical analysis: drugs were included in the analysis from the time of approval until the end of 2019 or the first post-marketing regulatory action related to hepatotoxicity, whichever occurred first. The hazard ratio (HR) was estimated using Cox-regression analysis. Results: We included 192 medications in the study. We classified 48 drugs as having grade ≥ 3 hepatotoxicities, 43 had accelerated approval status, and 74 had labeled information about hepatotoxicity prior to marketing. The adjusted HRs for post-marketing regulatory action for products with grade ≥ 3 hepatotoxicity was 0.61 (95% confidence interval [CI], 0.17-2.23), 0.92 (95%CI, 0.29-2.93) for a drug approved via accelerated approval program, and was 0.91 (95%CI, 0.33-2.56) for drugs with labeled hepatotoxicity information at approval time. Conclusion: This study does not provide conclusive evidence on the association between post-marketing regulatory action and grade ≥ 3 hepatotoxicity, accelerated approval status, or availability of labeled information at approval due to sampling size and channeling bias.

Keywords: accelerated approvals, hepatic adverse effects, drug-induced liver injury, hepatotoxicity predictors, post-marketing withdrawal

Procedia PDF Downloads 152

Authors: Bendjazia Radia, Samira Kilani-Morakchi, Nadia Aribi

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Azadirachtin is a biorational insecticide commonly reported as selective to a range of beneficial insects. It is one of the most biologically active natural inhibitors of insect growth and development and it is known to be an antagonist of the juvenile hormone and 20-hydroxyecdysone (20E). However, its mechanism of action remains still unknown. In the present study, the toxicity of a commercial formulation of Azadirachtin (Neem Azal, 1% azadirachtine) was evaluated by topical application at various doses (0.1, 0.25, 0.5, 1 and 2 µg/insect) on the third instars larvae of D. melanogaster. Lethal doses (LD25: 0.28µg and LD50: 0.67µg), were evaluated by cumulated mortality at the immature stages. The effects of azadirachtin (LD25 and LD50) were then evaluated on the development (duration of the larval and pupal instars, the weight of larvae, pupa and adults) of Drosophila melanogaster. Results showed that the insecticide increased significantly the larval and pupal instar duration. A reduction of larval and pupal weight is noted under azadirachtin treatment as compared to controls. In addition, the weight of surviving adults at the two tested dose was also reduced. In conclusion, azadirachtin seemed to interfere with the functions of the endocrine system resulting in development defects.

Keywords: azadirachtin, d.melanogaster, toxicity, development

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Authors: Foad Hassaninejadafarahani, Scott Ormiston

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Reflux condensation occurs in a vertical channels and tubes when there is an upward core flow of vapor (or gas-vapor mixture) and a downward flow of the liquid film. The understanding of this condensation configuration is crucial in the design of reflux condensers, distillation columns, and in loss-of-coolant safety analyses in nuclear power plant steam generators. The unique feature of this flow is the upward flow of the vapor-gas mixture (or pure vapor) that retards the liquid flow via shear at the liquid-mixture interface. The present model solves the full, elliptic governing equations in both the film and the gas-vapor core flow. The computational mesh is non-orthogonal and adapts dynamically the phase interface, thus produces sharp and accurate interface. Shear forces and heat and mass transfer at the interface are accounted for fundamentally. This modeling is a big step ahead of current capabilities by removing the limitations of previous reflux condensation models which inherently cannot account for the detailed local balances of shear, mass, and heat transfer at the interface. Discretisation has been done based on a finite volume method and a co-located variable storage scheme. An in-house computer code was developed to implement the numerical solution scheme. Detailed results are presented for laminar reflux condensation from steam-air mixtures flowing in vertical parallel plate channels. The results include velocity and pressure profiles, as well as axial variations of film thickness, Nusselt number and interface gas mass fraction.

Keywords: Reflux, Condensation, CFD-Two Phase, Nusselt number

Procedia PDF Downloads 364

Authors: Rama Krishna Supramanian, Marzuki Isahak, Noran Naqiah Hairi

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Noise-induced hearing loss (NIHL) is one of the highest recorded occupational diseases, despite being preventable. Hearing Conservation Program (HCP) is designed to protect workers hearing and prevent them from developing hearing impairment due to occupational noise exposures. However, there is still a lack of evidence regarding the effectiveness of this program. The purpose of this study was to determine the effectiveness of a Hearing Conservation Program (HCP) in preventing or reducing audiometric threshold changes among vector control workers. This study adopts a cluster randomized controlled trial study design, with district health offices as the unit of randomization. Nine district health offices were randomly selected and 183 vector control workers were randomized to intervention or control group. The intervention included a safety and health policy, noise exposure assessment, noise control, distribution of appropriate hearing protection devices, training and education program and audiometric testing. The control group only underwent audiometric testing. Audiometric threshold changes observed in the intervention group showed improvement in the hearing threshold level for all frequencies except 500 Hz and 8000 Hz for the left ear. The hearing threshold changes range from 1.4 dB to 5.2 dB with largest improvement at higher frequencies mainly 4000 Hz and 6000 Hz. Meanwhile for the right ear, the mean hearing threshold level remained similar at 4000 Hz and 6000 Hz after 3 months of intervention. The Hearing Conservation Program (HCP) is effective in preserving the hearing of vector control workers involved in fogging activity as well as increasing their knowledge, attitude and practice towards noise-induced hearing loss (NIHL).

Keywords: adult, hearing conservation program, noise-induced hearing loss, vector control worker

Procedia PDF Downloads 168

Authors: O. Altuntaş, A. Güral

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The hardness-microstructure relationships of spherical cementite in bainitic matrix obtained by a different heat treatment cycles carried out to high carbon powder metallurgy (P/M) steel were investigated. For this purpose, 1.5 wt.% natural graphite powder admixed in atomized iron powders and the mixed powders were compacted under 700 MPa at room temperature and then sintered at 1150 °C under a protective argon gas atmosphere. The densities of the green and sintered samples were measured via the Archimedes method. A density of 7.4 g/cm³ was obtained after sintering and a density of 94% was achieved. The sintered specimens having primary cementite plus lamellar pearlitic structures were fully quenched from 950 ^°C temperature and then over-tempered at 705 °C temperature for 60 minutes to produce spherical-fine cementite particles in the ferritic matrix. After by this treatment, these samples annealed at 735 °C temperature for 3 minutes were austempered at 300 °C salt bath for a period of 1 to 5 hours. As a result of this process, it could be able to produced spherical cementite particle in the bainitic matrix. This microstructure was designed to improve wear and toughness of P/M steels. The microstructures were characterized and analyzed by SEM and micro and macro hardness.

Keywords: powder metallurgy steel, bainite, cementite, austempering and spheroidization heat treatment

Procedia PDF Downloads 161

Authors: A. Bahieldin, A. Atef, S. Edris, N. O. Gadalla, S. M. Hassan, M. A. Al-Kordy, A. M. Ramadan, A. S. M. Al- Hajar, F. M. El-Domyati

Abstract:

The idea of this work is based on a natural exciting phenomenon suggesting that suppression of genes related to the program cell death (or PCD) mechanism might help the plant cells to efficiently tolerate abiotic stresses. The scope of this work was the detection of PCD-related transcription factors (TFs) that might also be related to salt stress tolerance in plant. Two model plants, e.g., tobacco and Arabidopsis, were utilized in order to investigate this phenomenon. Occurrence of PCD was first proven by Evans blue staining and DNA laddering after tobacco leaf discs were treated with oxalic acid (OA) treatment (20 mM) for 24 h. A number of 31 TFs up regulated after 2 h and co-expressed with genes harboring PCD-related domains were detected via RNA-Seq analysis and annotation. These TFs were knocked down via virus induced gene silencing (VIGS), an RNA interference (RNAi) approach, and tested for their influence on triggering PCD machinery. Then, Arabidopsis SALK knocked out T-DNA insertion mutants in selected TFs analogs to those in tobacco were tested under salt stress (up to 250 mM NaCl) in order to detect the influence of different TFs on conferring salt tolerance in Arabidopsis. Involvement of a number of candidate abiotic-stress related TFs was investigated.

Keywords: VIGS, PCD, RNA-Seq, transcription factors

Procedia PDF Downloads 274

Authors: Esteban Hincapie

Abstract:

The growing climate change, global warming and population growth have contributed to the energy crisis, aggravated by the generation of organic solid waste, as a material with high energy potential. From the context of waste generation in the Metropolitan Area of the Aburrá Valley, was evaluated the potential of energy content in organic solid waste generated in La Herradura housing complex, through anaerobic digestion process in batch reactors, with mixtures of substrate, water and inoculum 1: 3: 0.2 and 1: 3: 0, reaching a total biogas production of 0,2 m³/Kg y 0,14 m³/Kg respectively, in a period of 38 days under temperature conditions of 24°C. The volume of biogas obtained was equivalent to the monthly consumption of natural gas for 75 apartments or 1.856 Kw of electric power. For the Metropolitan Area of the Aburrá Valley, a production of 7.152Kw of electric power was estimated for a month, from the treatment of 22.319 tons of organic solid waste that would not be taken to the landfill. The results indicate that the treatment of organic waste from anaerobic digestion is a sustainable option to reduce pollution, contribute to the production of alternative energies and improve the efficiency of urban metabolism.

Keywords: alternative energies, anaerobic digestion, solid waste, sustainable construction, urban metabolism, waste management

Procedia PDF Downloads 180

Authors: Mahmoud M. Tash

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The present study was undertaken to investigate the effect of aging parameters (time and temperature) on the mechanical properties of Be-and/or Zr- treated Al-Mg-Zn (7075) alloys. Ultimate tensile strength, 0.5% offset yield strength and % elongation measurements were carried out on specimens prepared from cast and heat treated 7075 alloys containing Be and/or Zr. Different aging treatment were carried out for the as solution treated (SHT) specimens. The specimens were aged at different conditions; Natural and artificial aging was carried out at room temperature, 120C, 150C, 180C and 220C for different periods of time. Duplex aging was performed for SHT conditions (pre-aged at different time and temperature followed by high temperature aging). Ultimate tensile strength, yield strength and % elongation data results as a function of different aging parameters are analysed. A statistical design of experiments (DOE) approach using fractional factorial design is applied to acquire an understanding of the effects of these variables and their interactions on the mechanical properties of Be- and/or Zr- treated 7075 alloys. Mathematical models are developed to relate the alloy mechanical properties with the different aging parameters.

Keywords: casting aging treatment, mechanical properties, Al-Mg-Zn alloys, Be- and/or Zr-treatment, experimental correlation

Procedia PDF Downloads 364

Authors: Ahmed M. Al-Mahbashi, Mosleh A. Al-Shamrani, Muawia Dafalla

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Mixtures of sand and clay are frequently used to serve for specific purposes in several engineering practices. In environmental engineering, liner layers and cover layers are common for controlling waste disposal facilities. These layers are exposed to moisture and temperature fluctuation specially when existing in unsaturated condition. The relationship between soil suction and water content for these materials is essential for understanding their unsaturated behavior and properties such as retention capacity and unsaturated follow (hydraulic conductivity). This study is aimed at investigating retention capacity for two sand-natural expansive clay mixtures (15% (C15) and 30% (C30) expansive clay) at two ambient temperatures within the range of 5 -50 °C. Soil water retention curves (SWRC) for these materials were determined at these two ambient temperatures using different salt solutions for a wide range of suction (up to 200MPa). The results indicate that retention capacity of C15 mixture underwent significant changes due to temperature variations. This effect tends to be less visible when the clay fraction is doubled (C30). In addition, the overall volume change is marginally affected by high temperature within the range considered in this study.

Keywords: soil water retention curve, sand-expansive clay liner, suction, temperature

Procedia PDF Downloads 139

Authors: F. Longo, G. Granello, G. Tecchio, F. Da Porto

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Unreinforced masonry (URM) infill walls are widely used throughout the world, also in seismic prone regions, as partitions in reinforced concrete building frames. Even if they do not represent structural elements, they can dramatically affect both strength and stiffness of RC structures by acting as a diagonal strut, modifying shear and displacements distribution along the building height, with uncertain consequences on structural safety. In the last decades, many refined models have been developed to describe infill walls effect on frame structural behaviour, but generally restricted to in-plane actions. Only very recently some new approaches were implemented to consider in-plane/out-of-plane interaction of URM infill walls in progressive collapse simulations. In the present work, a particularly promising macro-model was adopted for the progressive collapse analysis of infilled RC frames. The model allows to consider the bi-directional interaction in terms of displacement and strength capacity for URM infills, and to remove the infill contribution when the URM wall is supposed to fail during the analysis process. The model was calibrated on experimental data regarding two different URM panels thickness, modelling with particular care the post-critic softening branch. A frame specimen set representing the most common Italian structures was built considering two main normative approaches: a traditional design philosophy, corresponding to structures erected between 50’s-80’s basically designed to support vertical loads, and a seismic design philosophy, corresponding to current criteria that take into account horizontal actions. Non-Linear Static analyses were carried out on the specimen set and some preliminary evaluations were drawn in terms of different performance exhibited by the RC frame when the contemporary effect of the out-of-plane damage is considered for the URM infill.

Keywords: infill Panels macromodels, in plane-out of plane interaction, RC frames, URM infills

Procedia PDF Downloads 516

Authors: Fabienne Baraud, Lydia Leleyter, Sandra Poree, Melanie Lemoine

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SEDIBRIC (valorization de SEDIments en BRIQues et tuiles) is a French project that aims to replace a part of natural clays with dredged sediments in the preparation of fired bricks in order to propose an alternative solution for the management of harbor dredged sediments. The feasibility of such re-use is explored from a technical, economic, and environmental point of view. The present study focuses on the potential environmental impact of various chemical elements (Al, Ca, Cd, Co, Cr, Cu, Fe, Ni, Mg, Mn, Pb, Ti, and Zn) that are initially present in the dredged sediments. The total content (after acid digestion) and the environmental availability (estimated by single extractions with various extractants) of these elements are determined in the raw sediments and in the obtained fired bricks. The possible influence of some steps of the manufacturing process (sediment pre-treatment, firing) is also explored. The first results show that the pre-treatment step, which uses tap water to desalinate the raw sediment, does not influence the environmental availability of the studied elements. However, the firing process, performed at 900°C, can affect the amount of some elements detected in the bricks, as well as their environmental availability. We note that for Cr, or Ni, the HCl or EDTA availability was increased in the brick (compared to the availability in the raw sediment). For Cd, Cu, Pb, and Zn, the HCl and EDTA availability was reduced in the bricks, meaning that these elements were stabilized within the bricks.

Keywords: bricks, chemical extraction, metals, sediment

Procedia PDF Downloads 150

Authors: Arpita Roy, Navneeta Bharadvaja

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Cancer is an uncontrolled growth of abnormal cells in the body. It is one of the most serious diseases on which extensive research work has been going on all over the world. Structure-based drug designing is a computational approach which helps in the identification of potential leads that can be used for the development of a drug. Plumbagin is a naphthoquinone derivative from Plumbago zeylanica roots and belongs to one of the largest and diverse groups of plant metabolites. Anticancer and antiproliferative activities of plumbagin have been observed in animal models as well as in cell cultures. Plumbagin shows inhibitory effects on multiple cancer-signaling proteins; however, the binding mode and the molecular interactions have not yet been elucidated for most of these protein targets. In this investigation, an attempt to provide structural insights into the binding mode of plumbagin against four cancer receptors using molecular docking was performed. Plumbagin showed minimal energy against targeted cancer receptors, therefore suggested its stability and potential towards different cancers. The least binding energies of plumbagin with COX-2, TACE, and CDK6 are -5.39, -4.93, -and 4.81 kcal/mol, respectively. Comparison studies of plumbagin with different receptors showed that it is a promising compound for cancer treatment. It was also found that plumbagin obeys the Lipinski’s Rule of 5 and computed ADMET properties which showed drug likeliness and improved bioavailability. Since plumbagin is from a natural source, it has reduced side effects, and these results would be useful for cancer treatment.

Keywords: cancer, receptor, plumbagin, docking

Procedia PDF Downloads 143

Authors: Sang Koo Jeon, Seung Hoon Nahm, Oh Heon Kwon

Abstract:

The unit cell of solid oxide fuel cell (SOFC) must be stacked as several layers type to obtain the high power. The most of researcher have concerned about the performance of stacked SOFC rather than the structural stability of stacked SOFC and especially interested how to design for reducing the electrical loss and improving the high efficiency. Consequently, the stacked SOFC able to produce the electrical high power and related parts like as manifold, gas seal, bipolar plate were developed to optimize the stack design. However, the unit cell of SOFC was just layered on the interconnector without the adhesion and the hydrogen and oxygen were injected to the interfacial layer in the high temperature. On the operating condition, the interfacial layer can be the one of the weak point in the stacked SOFC. Therefore the evaluation of the structural safety for the failure is essentially needed. In this study, interfacial adhesion between SOFC and metal adhesive was estimated in the high temperature environment. The metal adhesive was used to strongly connect the unit cell of SOFC with interconnector and provide the electrical conductivity between them. The four point bending test was performed to measure the interfacial adhesion. The unit cell of SOFC and SiO2 wafer were diced and then attached by metal adhesive. The SiO2 wafer had the center notch to initiate a crack from the tip of the notch. The modified stereomicroscope combined with the CCD camera and system for measuring the length was used to observe the fracture behavior. Additionally, the interfacial adhesion was evaluated in the high temperature condition because the metal adhesive was affected by high temperature. Also the specimen was exposed in the furnace during several hours and then the interfacial adhesion was evaluated. Finally, the interfacial adhesion energy was quantitatively determined and compared in the each condition.

Keywords: solid oxide fuel cell (SOFC), metal adhesive, adhesion, high temperature

Procedia PDF Downloads 521