Search results for: food raw material

Authors: Bruno C. Schimming, Leandro L. Martins, PatríCia F. F. Pinheiro, Raquel F. Domeniconi, FabríCio S. Oliveira

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The agouti is a wildlife rodent that can be used as an alternative source of animal protein and this species has been raised in captivity in Brazil with the aim of providing meat. Thus, the knowledge of their reproductive biology and morphology of the reproductive organs is important. The objective of this study was to describe the morphology of epididymis in the Azara’s agouti, by light microscopy. Samples of epididymis were obtained from five adult Azara’s agouti (Dasyprocta azarae) during castration surgery performed at the Municipal Zoo of Catanduva, Brazil. Fragments of the epididymal regions (initial segment, caput, corpus and cauda) were collected. The biological samples were immediately fixed in paraformaldehyde for 24 hours, followed by histologic procedures comprising embedding in ParaplastTM (Sigma, St. Louis, MO, USA), sections of 5 µm, and staining with HE and Masson’s trichrome. The epididymis was a highly convoluted tubule that links the testis to the vas deferens. The epithelium lining was pseudostratified columnar surrounded by a periductal stroma. The epithelium contains several cell types: principal, basal, apical, clear, and hallo cells. Principal cells were the most abundant cell type. There were observed also migratory cells named halo cells. The caput epididymis was divided into two different regions: initial segment and caput. The initial segment has a very wide lumen, a high epithelium with conspicuous microvilli and the lumen was wide with exfoliated material. The other region of the caput epididymis, showed a lower epithelium when compared with the initial segment, large amounts of spermatozoa in the lumen, and a cytoplasmic vacuolization. This region presented many narrows cells. Many spermatozoa appeared in the lumen of corpus epididymis. The cauda region had a lower epithelium than the other epididymal regions in the agouti. The cauda epithelium presented plicae protruding into the lumen. Large amounts of spermatozoa are also present in the lumen. Small microvilli uniformly arranged so as to form a kind of “brush border” are observed on the apical surface of the cauda epithelium. The pattern of the epithelium lining the duct of the agouti epididymis does not differ greatly from that reported to other mammals, such as domestic and wildlife animals. These findings can cooperate with future investigations especially those related to rational exploration of these animals. All experimental procedures were approved by the institutional ethics committee (CEUA 796/2015). This study was supported by FAPESP (Grants 2015/23822-1).

Keywords: wildlife, testis excurrent ducts, epididymis, morphology

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Authors: A. J. Cobley, L. Krishnan

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The demand for multi-functional lightweight materials in sectors such as automotive, aerospace, electronics is growing, and for this reason fibre-reinforced, epoxy polymer composites are being widely utilized. The fibre reinforcing material is mainly responsible for the strength and stiffness of the composites whilst the main role of the epoxy polymer matrix is to enhance the load distribution applied on the fibres as well as to protect the fibres from the effect of harmful environmental conditions. The superior properties of the fibre-reinforced composites are achieved by the best properties of both of the constituents. Although factors such as the chemical nature of the epoxy and how it is cured will have a strong influence on the properties of the epoxy matrix, the method of mixing and degassing of the resin can also have a significant impact. The production of a fibre-reinforced epoxy polymer composite will usually begin with the mixing of the epoxy pre-polymer with a hardener and accelerator. Mechanical methods of mixing are often employed for this stage but such processes naturally introduce air into the mixture, which, if it becomes entrapped, will lead to voids in the subsequent cured polymer. Therefore, degassing is normally utilised after mixing and this is often achieved by placing the epoxy resin mixture in a vacuum chamber. Although this is reasonably effective, it is another process stage and if a method of mixing could be found that, at the same time, degassed the resin mixture this would lead to shorter production times, more effective degassing and less voids in the final polymer. In this study the effect of four different methods for mixing and degassing of the pre-polymer with hardener and accelerator were investigated. The first two methods were manual stirring and magnetic stirring which were both followed by vacuum degassing. The other two techniques were ultrasonic mixing/degassing using a 40 kHz ultrasonic bath and a 20 kHz ultrasonic probe. The cured cast resin samples were examined under scanning electron microscope (SEM), optical microscope, and Image J analysis software to study morphological changes, void content and void distribution. Three point bending test and differential scanning calorimetry (DSC) were also performed to determine the thermal and mechanical properties of the cured resin. It was found that the use of the 20 kHz ultrasonic probe for mixing/degassing gave the lowest percentage voids of all the mixing methods in the study. In addition, the percentage voids found when employing a 40 kHz ultrasonic bath to mix/degas the epoxy polymer mixture was only slightly higher than when magnetic stirrer mixing followed by vacuum degassing was utilized. The effect of ultrasonic mixing/degassing on the thermal and mechanical properties of the cured resin will also be reported. The results suggest that low frequency ultrasound is an effective means of mixing/degassing a pre-polymer mixture and could enable a significant reduction in production times.

Keywords: degassing, low frequency ultrasound, polymer composites, voids

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Authors: Pushp Lata Sankhwar

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INTRODUCTION: Maternal Hypothyroidism is the most frequent endocrine disorder in pregnancy and varies from 2.5% in the west to 11.0% in India. Maternal Hypothyroidism can have detrimental maternal effects like increased risk of preterm labor, PPROM leading to increased maternal morbidity and also on the neonate in the form of prematurity and its complications, prolonged hospital stay, neurological developmental problems, delayed milestones and mental retardation etc. Henceforth, the study was planned to evaluate the role of Hypothyroidism in preterm labor and its effect on neonates. AIMS AND OBJECTIVES: To Correlate Overt Hypothyroidism, Subclinical Hypothyroidism and Isolated Hypothyroxinemia With Preterm Labor and the neonatal outcome. Material and Methods: A case-control study of singleton pregnancy was performed over a year, in which a total of 500 patients presenting in the emergency with preterm labor were enrolled. The thyroid profile of these patients was sent at the time of admission, on the basis of which they were divided into Cases – Hypothyroidic mothers and Controls – Euthyroid mothers. The cases were further divided into subclinical, overt Hypothyroidism and isolated hypothyroxinemia. The neonatal outcome of these groups was also compared on the basis of the incidence and severity of neonatal morbidity, neonatal respiratory distress, the incidence of neonatal Hypothyroidism and early complications. The feto-maternal data was collected and analysed. RESULTS: In the study, a total of 500 antenatal patients with a history of preterm labor were enrolled, out of which 67 (13.8%) patients were found to be hypothyroid. The majority of the mothers had Subclinical Hypothyroidism (12.2%), followed by Overt Hypothyroidism seen in 1% of the mothers and isolated hypothyroxinemia in 0.6% of cases. The neonates of hypothyroid mothers had higher levels of cord blood TSH, and the mean cord blood TSH levels were highest in the case of neonates of mothers with Overt Hypothyroidism. The need for resuscitation of the neonates at the time of birth was higher in the case of neonates of hypothyroid mothers, especially with Subclinical Hypothyroidism. Also, it was found that the requirement of oxygen therapy in the form of oxygen by nasal prongs, oxygen by a hood, CPAP, CPAP along with surfactant therapy and mechanical ventilation along with surfactant therapy was significantly higher in the case of neonates of hypothyroid mothers. CONCLUSION: The results of our study imply that uncontrolled and untreated maternal Hypothyroidism may also lead to preterm delivery. The neonates of mothers with Hypothyroidism have higher cord blood TSH levels. The study also shows that there is an increased incidence and severity of respiratory distress in the neonates of hypothyroid mothers with untreated subclinical Hypothyroidism. Hence, we propose that routine screening for thyroid dysfunction in pregnant women should be done to prevent thyroid-related feto-maternal complications.

Keywords: high-risk pregnancy, thyroid, dysfunction, hypothyroidism, Preterm labor

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Authors: Sukhdev Singh, Baljinder Singh Bal, Amandeep Singh, Kanchan Thappa

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A nation's future almost certainly rests on the future of its children, and a nation's wellbeing can be greatly improved by providing for the right upbringing of its children. Participating in physical education and sports programmes is crucial for reaching one's full potential. As we are all aware, sports have recently become incredibly popular on a global scale. Sports are continually becoming more and more popular, and this positive trend is probably going to last for some time to come. Motor abilities will provide more accurate information on the developmental process of children. Motor fitness is a component of physical fitness that includes strength, speed, flexibility, and agility, and is related to enhanced performance and the development of motor skills. In recent years, there has been increased interest in the differences in child growth between urban and rural environments. Differences in student growth, body dimensions, body composition, and fitness levels due to urban and rural environmental disparities have come into focus in recent years. The main aim of this study is to know the differentials of motor fitness components among the school children of rural and urban areas of the Jammu region. Material and Methods: In total, sixty male subjects (mean ± SD; age, 16.475 ± 1.0124 yrs.; height, 172.8 ± 2.0153 cm; Weight, 59.75 ± 3.628 kg) from the Jammu region took part in the study. A minimum sample size of 40 subjects was obtained and was derived from Rural (N1=20) and Urban (N2=20) school-going children. Statistical Applications: The Statistical Package for the Social Sciences (SPSS) version 14.0 was used for all analyses. The differences in the mean of each group for the selected variable were tested for the significance of difference by an independent samples t-test. For testing the hypotheses, the level of significance was set at 0.05. Results: Results revealed that there were significant differences of leg explosive strength (p=0.0040*), dynamic balance (p=0.0056*), and Agility (p=0.0176*) among the School Children of the rural and urban areas of the Jammu region. However, Results further revealed that there were not significant differences of cardio respiratory endurance (p=0.8612), speed (p=0.2231), Low Back/Hamstring Flexibility (p=0.6478), and Two Hand Coordination. (p= 0.0953) among the School Children of the rural and urban areas of the Jammu region. Conclusion: The results of study showed that there is significance difference between Rural and Urban School children of the Jammu region with regards to a variable," leg explosive strength, dynamic balance, Agility” and the there is no significance difference between Rural and Urban School children of the Jammu region with regards variable “cardio-respiratory endurance, speed, Low Back/Hamstring Flexibility, Two Hand Coordination”.

Keywords: motor fitness, rural areas, school children, urban areas

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Authors: Tom Elias, Kiran G. Shirlal

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Coastal erosion is one of the major issue faced by maritime countries, globally. More than 1200 km stretch of Indian coastline is marked eroding. There have been numerous attempts to impede the erosion rate and to attain equilibrium beach profiles. High cost and unavailability of natural rocks forced coastal engineers to find alternatives for conventional hard options like seawalls and groynes. Geosynthetic containment systems, emerged in the mid 20th century proved promising in catering coastal protection in countries like Australia, Germany and United States. The present study aims at reviewing Indian timeline of protection works that uses geosynthetic containment systems. Indian exploration regarding geosynthetic containment system dates back to early 2000s. Generally, protection structures use geosynthetics in the form of Geotubes, Geocontainers, and Geobags with Geotubes being most widely used in the form of submerged reefs, seawalls, groynes and breakwaters. Sand and dredged waste are used to fill these containment systems with calculated sand fill ratio. Reviewing the prominent protection works constructed in the east and west coast of India provides an insight into benefits and the difficulties faced by the practical installation. Initially, geosynthetic structures were considered as a temporary protection method prior to the construction of some other hard structure. Later Dahanu, Hamala and Pentha experiences helped in establishing geotubes as an alternative to conventional structures. Nearshore geotubes reefs aimed to attain equilibrium beach served its purpose in Hamala and Dahanu, Maharashtra, while reef constructed at Candolim, Goa underwent serious damage due to Toe Scour. In situ filling by pumping of sand slurry as in case of Shankarpur Seawall, West Bengal remains as a major concern. Geosynthetic systems supplemented by gabions and rock armours improves the wave dissipation, stability and reflection characteristics as implied in Pentha Coast, Odisha, Hazira, Gujarat and Uppada, Andhra Pradesh. Keeping improper design and deliberate destruction by vandals apart, geosynthetic containment systems offer a cost-effective alternative to conventional coastal protection methods in India. Additionally, geosynthetics supports marine growth in its surface which enhances its demand as an eco-friendly material and encourages usage.

Keywords: coastal protection, geotubes, geobags, geocontainers

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Authors: Deepak Loura

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Production and productivity of several crops in the country continue to be adversely affected by biotic (e.g., Insect-pests and diseases) and abiotic (e.g., water temperature and salinity) stresses. Over-dependence on pesticides and other chemicals is economically non-viable for the resource-poor farmers of our country. Further, pesticides can potentially affect human and environmental safety. While traditional breeding techniques and proper- management strategies continue to play a vital role in crop improvement, we need to judiciously use biotechnology approaches for the development of genetically modified crops addressing critical problems in the improvement of crop plants for sustainable agriculture. Modern biotechnology can help to increase crop production, reduce farming costs, and improve food quality and the safety of the environment. Genetic engineering is a new technology which allows plant breeders to produce plants with new gene combinations by genetic transformation of crop plants for improvement of agronomic traits. Advances in recombinant DNA technology have made it possible to have genes between widely divergent species to develop genetically modified or genetically engineered plants. Plant genetic engineering provides the strength to harness useful genes and alleles from indigenous microorganisms to enrich the gene pool for developing genetically modified (GM) crops that will have inbuilt (inherent) resistance to insect pests, diseases, and abiotic stresses. Plant biotechnology has made significant contributions in the past 20 years in the development of genetically engineered or genetically modified crops with multiple benefits. A variety of traits have been introduced in genetically engineered crops which include (i) herbicide resistance. (ii) pest resistance, (iii) viral resistance, (iv) slow ripening of fruits and vegetables, (v) fungal and bacterial resistance, (vi) abiotic stress tolerance (drought, salinity, temperature, flooding, etc.). (vii) quality improvement (starch, protein, and oil), (viii) value addition (vitamins, micro, and macro elements), (ix) pharmaceutical and therapeutic proteins, and (x) edible vaccines, etc. Multiple genes in transgenic crops can be useful in developing durable disease resistance and a broad insect-control spectrum and could lead to potential cost-saving advantages for farmers. The development of transgenic to produce high-value pharmaceuticals and the edible vaccine is also under progress, which requires much more research and development work before commercially viable products will be available. In addition, molecular-aided selection (MAS) is now routinely used to enhance the speed and precision of plant breeding. Newer technologies need to be developed and deployed for enhancing and sustaining agricultural productivity. There is a need to optimize the use of biotechnology in conjunction with conventional technologies to achieve higher productivity with fewer resources. Therefore, genetic modification/ engineering of crop plants assumes greater importance, which demands the development and adoption of newer technology for the genetic improvement of crops for increasing crop productivity.

Keywords: biotechnology, plant genetic engineering, genetically modified, biotic, abiotic, disease resistance

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Authors: Mustafa Var, Yasin Kültiğin Yaman, Elif Berna Var, Müberra Pulatkan

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This study deals with real application of an urban transformation project in Trabzon, Turkey. It aims to highlight the significance of using native species in terms of planting design of transformation projects which will also promote sustainability of urban identity. Urban identity is a phenomenon shaped not only by physical, but also by natural, spatial, social, historical and cultural factors. Urban areas face with continuous change which can be whether positive or negative way. If it occurs in a negative way that may have some destructive effects on urban identity. To solve this problematic issue, urban renewal movements initally started after 1840s around the world especially in the cities with ports. This process later followed by the places where people suffered a lot from fires and has expanded to all over the world. In Turkey, those processes have been experienced mostly after 1980s as country experienced the worst effects of unplanned urbanization especially in 1950-1990 period. Also old squares, streets, meeting points, green areas, Ottoman bazaars have changed slowly. This change was resulted in alienation of inhabitants to their environments. As a solution, several actions were taken like Mass Housing Laws which was enacted in 1981 and 1984 or urban transformation projects. Although projects between 1990-2000 were tried to satisfy the expectations of local inhabitants by the help of several design solutions to promote cultural identity; unfortunately those modern projects has also been resulted in alienation of urban environments to the inhabitants. Those projects were initially done by TOKI (Housing Development Administration of Turkey) and later followed by the Ministry of Environment and Urbanization after 2011. Although they had significant potentials to create healthy urban environments, they could not use this opportunity in an effective way. The reason for their failure is that their architectural styles and planting designs are unrespectful to local identity and environments. Generally, it can be said that the most of the urban transformation projects implementing in Turkey nearly have no concerns about the locality. However, those projects can be used as a positive tool for enhanching the urban identity of cities by means of local planting material. For instance, Kyoto can be identified by Japanese Maple trees or Seattle can be specified by Dahlia. In the same way, in Turkey, Istanbul city can be identified by Judas and Stone Pine trees or Giresun city can be identified by Cherry trees. Thus, in this paper, the importance of conserving urban identity is discussed specificly with the help of using local planting elements. After revealing the mistakes that are made during urban transformation projects, the techniques and design criterias for preserving and promoting urban identity are examined. In the end, it is emphasized that every city should have their own original, local character and specific planting design which can be used for highlighting its identity as well as architectural elements.

Keywords: urban identity, urban transformation, planting design, landscape architecture

Procedia PDF Downloads 545

Authors: Dinesh Munjurulimana, Anil Tiwari, Tingwen Li, Carlos Pereira, Sreekanth Pannala, John Waters

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With the rapid transition to electric vehicles (EVs) across the globe, car manufacturers are in need of integrated and lightweight solutions for the battery packs of these vehicles. An integral part of a battery pack is the battery tray, which constitutes a significant portion of the pack’s overall weight. Based on the functional requirements, cost targets, and packaging space available, a range of materials –from metals, composites, and plastics– are often used to develop these battery trays. This paper considers the design and development of integrated thermoplastic-intensive battery trays, using the available packaging space from a representative EV battery pack. Presented as a proposed alternative are multiple concepts to integrate several connected systems such as cooling plates and underbody impact protection parts of a multi-piece incumbent battery pack. The resulting digital prototype was evaluated for several mechanical performance measures such as mechanical shock, drop, crush resistance, modal analysis, and torsional stiffness. The performance of this alternative design is then compared with the incumbent solution. In addition, insights are gleaned into how these novel approaches can be optimized to meet or exceed the performance of incumbent designs. Preliminary manufacturing feasibility of the optimal solution using injection molding and other commonly used manufacturing methods for thermoplastics is briefly explained. Then numerical and analytical evaluations are performed to show a representative Pareto front of cost vs. volume of the production parts. The proposed solution is observed to offer weight savings of up to 40% on a component level and part elimination of up to two systems in the battery pack of a typical battery EV while offering the potential to meet the required performance measures highlighted above. These conceptual solutions are also observed to potentially offer secondary benefits such as improved thermal and electrical isolations and be able to achieve complex geometrical features, thus demonstrating the ability to use the complete packaging space available in the vehicle platform considered. The detailed study presented in this paper serves as a valuable reference for researches across the globe working on the development of EV battery packs – especially those with an interest in the potential of employing alternate solutions as part of a mixed-material system to help capture untapped opportunities to optimize performance and meet critical application requirements.

Keywords: thermoplastics, lightweighting, part integration, electric vehicle battery packs

Procedia PDF Downloads 204

Authors: Benoit Atge, Alice Dhersin, Oscar Da Silva Cacao, Beatrice Martinez, Dominique Ducint, Catherine Verdun-Esquer, Isabelle Baldi, Mathieu Molimard, Antoine Villa, Mireille Canal-Raffin

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Introduction: Healthcare workers' exposure to antineoplastic drugs (AD) is a burning issue for occupational medicine practitioners. Biological monitoring of occupational exposure (BMOE) is an essential tool for assessing AD contamination of healthcare workers. In addition to BMOE, surface sampling is a useful tool in order to understand how workers get contaminated, to identify sources of environmental contamination, to verify the effectiveness of surface decontamination way and to ensure monitoring of these surfaces. The objective of this work was to develop a complete tool including a kit for surface sampling and a quantification analytical method for AD traces detection. The development was realized with the three following criteria: the kit capacity to sample in every professional environment (healthcare services, veterinaries, etc.), the detection of very low AD traces with a validated analytical method and the easiness of the sampling kit use regardless of the person in charge of sampling. Material and method: AD mostly used in term of quantity and frequency have been identified by an analysis of the literature and consumptions of different hospitals, veterinary services, and home care settings. The kind of adsorbent device, surface moistening solution and mix of solvents for the extraction of AD from the adsorbent device have been tested for a maximal yield. The AD quantification was achieved by an ultra high-performance liquid chromatography method coupled with tandem mass spectrometry (UHPLC-MS/MS). Results: With their high frequencies of use and their good reflect of the diverse activities through healthcare, 15 AD (cyclophosphamide, ifosfamide, doxorubicin, daunorubicin, epirubicin, 5-FU, dacarbazin, etoposide, pemetrexed, vincristine, cytarabine, methothrexate, paclitaxel, gemcitabine, mitomycin C) were selected. The analytical method was optimized and adapted to obtain high sensitivity with very low limits of quantification (25 to 5000ng/mL), equivalent or lowest that those previously published (for 13/15 AD). The sampling kit is easy to use, provided with a didactic support (online video and protocol paper). It showed its effectiveness without inter-individual variation (n=5/person; n= 5 persons; p=0,85; ANOVA) regardless of the person in charge of sampling. Conclusion: This validated tool (sampling kit + analytical method) is very sensitive, easy to use and very didactic in order to control the chemical risk brought by AD. Moreover, BMOE permits a focal prevention. Used in routine, this tool is available for every intervention of occupational health.

Keywords: surface contamination, sampling kit, analytical method, sensitivity

Procedia PDF Downloads 129

Authors: Sidharth Talan, Sanjay Kumar Sharma, Eoin Joseph Wallace, Nikita Agrawal

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Underground mining is at the core of rapidly evolving metals and minerals sector due to the increasing mineral consumption globally. Even though the surface mines are still more abundant on earth, the scales of industry are slowly tipping towards underground mining due to rising depth and complexities of orebodies. Thus, the efficient and productive functioning of underground operations depends significantly on the synchronized performance of key elements such as operating site, mining equipment, manpower and mine services. Production drilling is the process of conducting long hole drilling for the purpose of charging and blasting these holes for the production of ore in underground metal mines. Thus, production drilling is the crucial segment in the underground metal mining value chain. This paper presents the process mapping tool to evaluate the production drilling process in the underground metal mining operation by dividing the given process into three segments namely Input, Process and Output. The three segments are further segregated into factors and sub-factors. As per the study, the major input factors crucial for the efficient functioning of production drilling process are power, drilling water, geotechnical support of the drilling site, skilled drilling operators, services installation crew, oils and drill accessories for drilling machine, survey markings at drill site, proper housekeeping, regular maintenance of drill machine, suitable transportation for reaching the drilling site and finally proper ventilation. The major outputs for the production drilling process are ore, waste as a result of dilution, timely reporting and investigation of unsafe practices, optimized process time and finally well fragmented blasted material within specifications set by the mining company. The paper also exhibits the drilling loss matrix, which is utilized to appraise the loss in planned production meters per day in a mine on account of availability loss in the machine due to breakdowns, underutilization of the machine and productivity loss in the machine measured in drilling meters per unit of percussion hour with respect to its planned productivity for the day. The given three losses would be essential to detect the bottlenecks in the process map of production drilling operation so as to instigate the action plan to suppress or prevent the causes leading to the operational performance deficiency. The given tool is beneficial to mine management to focus on the critical factors negatively impacting the production drilling operation and design necessary operational and maintenance strategies to mitigate them. 

Keywords: process map, drilling loss matrix, SIPOC, productivity, percussion rate

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Authors: Ikenna Stephen Ezennia, Sebnem Onal Hoscara

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Successive governments in Nigeria are faced with the pressing problem of how to house an ever-expanding urban population, usually low-income earners. The question of housing and affordability presents a complex challenge for these governments, as the commodification of housing links it inextricably to markets and capital flows. Therefore, placing it as at the center of the government’s agenda. However, the provision of decent and affordable housing for average Nigerians has remained an illusion, despite copious schemes, policies and programs initiated and carried out by various successive governments. Similarly, this phenomenon has also been observed in many countries of Africa, which is largely a result of economic unpredictability, lack of housing finance and insecurity, among other factors peculiar to a struggling economy. This study reviews recent dynamics and factors challenging the provision and development of affordable housing for the low income urban populace of Nigeria. Thus, the aim of the study is to present a comprehensive approach for understanding recent trends in the provision of affordable housing for Nigerians. The approach is based on a new paradigm of research: transdisciplinarity; a form of inquiry that crosses the boundaries of different disciplines. Therefore, the review takes a retrospective gaze at the various housing development programs/schemes/policies taken by successive governments of Nigeria within the last few decades and exams recent efforts geared towards eradicating the problems of housing delivery. Sources of data included relevant English language articles and the results of literature search of Elsevier Science Direct, ISI Web of Knowledge, Pro Quest Central, Scopus, and Google Scholar. The findings reveal that factors such as; rapid urbanization, inadequate planning and land use control, lack of adequate and favorable finance, high prices of land, high prices of building material, youth/touts harassment of developers, poor urban infrastructure, multiple taxation, and risk share are the major factors posing as a hindrance to adequate housing delivery. The results show that the majority of Nigeria’s affordable housing schemes, programs and policies are in most cases poorly implemented and abandoned without proper coordination. Consequently, the study concludes that the affordable housing delivery strategies in Nigeria are an epitome of lip service politics by successive governments; and the current trend of leaving housing provision to the vagaries of market forces cannot be expected to support affordable housing especially for the low income urban populace.

Keywords: affordable housing, housing delivery, national housing policy, urban poor

Procedia PDF Downloads 218

Authors: M. Kozłowski, M. Kadela

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Foamed concrete is known for its low self-weight and excellent thermal and acoustic properties. For many years, it has been used worldwide for insulation to foundations and roof tiles, as backfill to retaining walls, sound insulation, etc. However, in the last years it has become a promising material also for structural purposes e.g. for stabilization of weak soils. Due to favorable properties of foamed concrete, many interests and studies were involved to analyze its strength, mechanical, thermal and acoustic properties. However, these studies do not cover the investigation of fracture energy which is the core factor governing the damage and fracture mechanisms. Only limited number of publications can be found in literature. The paper presents the results of experimental investigation and numerical campaign of foamed concrete based on three-point bending test of beams with initial notch. First part of the paper presents the results of a series of static loading tests performed to investigate the fracture properties of foamed concrete of varying density. Beam specimens with dimensions of 100×100×840 mm with a central notch were tested in three-point bending. Subsequently, remaining halves of the specimens with dimensions of 100×100×420 mm were tested again as un-notched beams in the same set-up with reduced distance between supports. The tests were performed in a hydraulic displacement controlled testing machine with a load capacity of 5 kN. Apart from measuring the loading and mid-span displacement, a crack mouth opening displacement (CMOD) was monitored. Based on the load – displacement curves of notched beams the values of fracture energy and tensile stress at failure were calculated. The flexural tensile strength was obtained on un-notched beams with dimensions of 100×100×420 mm. Moreover, cube specimens 150×150×150 mm were tested in compression to determine the compressive strength. Second part of the paper deals with numerical investigation of the fracture behavior of beams with initial notch presented in the first part of the paper. Extended Finite Element Method (XFEM) was used to simulate and analyze the damage and fracture process. The influence of meshing and variation of mechanical properties on results was investigated. Numerical models simulate correctly the behavior of beams observed during three-point bending. The numerical results show that XFEM can be used to simulate different fracture toughness of foamed concrete and fracture types. Using the XFEM and computer simulation technology allow for reliable approximation of load–bearing capacity and damage mechanisms of beams made of foamed concrete, which provides some foundations for realistic structural applications.

Keywords: foamed concrete, fracture energy, three-point bending, XFEM

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Authors: Fang Li, Jiazhao Wang, Jianmin Ma

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The practical application of Li-S batteries is hampered due to poor cycling stability caused by electrolyte-dissolved lithium polysulfides. Dual functionalities such as strong chemical adsorption stability and high conductivity are highly desired for an ideal host material for a sulfur-based cathode. Polypyrrole (PPy), as a conductive polymer, was widely studied as matrixes for sulfur cathode due to its high conductivity and strong chemical interaction with soluble polysulfides. Thus, a novel cathode structure consisting of a free-standing sulfur-polypyrrole cathode and a polypyrrole coated separator was designed for flexible Li-S batteries. The PPy materials show strong interaction with dissoluble polysulfides, which could suppress the shuttle effect and improve the cycling stability. In addition, the synthesized PPy film with a rough surface acts as a current collector, which improves the adhesion of sulfur materials and restrain the volume expansion, enhancing the structural stability during the cycling process. For further enhancing the cycling stability, a PPy coated separator was also applied, which could make polysulfides into the cathode side to alleviate the shuttle effect. Moreover, the PPy layer coated on commercial separator is much lighter than other reported interlayers. A soft-packaged flexible Li-S battery has been designed and fabricated for testing the practical application of the designed cathode and separator, which could power a device consisting of 24 light-emitting diode (LED) lights. Moreover, the soft-packaged flexible battery can still show relatively stable cycling performance after repeated bending, indicating the potential application in flexible batteries. A novel vapor phase deposition method was also applied to prepare uniform polypyrrole layer coated sulfur/graphene aerogel composite. The polypyrrole layer simultaneously acts as host and adsorbent for efficient suppression of polysulfides dissolution through strong chemical interaction. The density functional theory (DFT) calculations reveal that the polypyrrole could trap lithium polysulfides through stronger bonding energy. In addition, the deflation of sulfur/graphene hydrogel during the vapor phase deposition process enhances the contact of sulfur with matrixes, resulting in high sulfur utilization and good rate capability. As a result, the synthesized polypyrrole coated sulfur/graphene aerogel composite delivers a specific discharge capacity of 1167 mAh g⁻¹ and 409.1 mAh g⁻¹ at 0.2 C and 5 C respectively. The capacity can maintain at 698 mAh g⁻¹ at 0.5 C after 500 cycles, showing an ultra-slow decay rate of 0.03% per cycle.

Keywords: polypyrrole, strong chemical interaction, long-term stability, Li-S batteries

Procedia PDF Downloads 140

Authors: Ismatilla Mardanov

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There are three types of countries, the first of which is willing to attract foreign direct investment (FDI) in enormous amounts and do whatever it takes to make this happen. Therefore, FDI pours into such countries. In the second cluster of countries, even if the country is suffering tremendously from the shortage of investments, the governments are hesitant to attract investments because they are at the hands of local oligarchs/cartels. Therefore, FDI inflows are moderate to low in such countries. The third type is countries whose companies prefer investing in the most efficient locations globally and are hesitant to invest in the homeland. Sorting countries into such clusters, the present study examines the essential institutions and economic factors that make these countries different. Past literature has discussed various determinants of FDI in all kinds of countries. However, it did not classify countries based on government motivation, institutional setup, and economic factors. A specific approach to each target country is vital for corporate foreign direct investment risk analysis and decisions. The research questions are 1. What specific institutional and economic factors paint the pictures of the three clusters; 2. What specific institutional and economic factors are determinants of FDI; 3. Which of the determinants are endogenous and exogenous variables? 4. How can institutions and economic and political variables impact corporate investment decisions Hypothesis 1: In the first type, country institutions and economic factors will be favorable for FDI. Hypothesis 2: In the second type, even if country economic factors favor FDI, institutions will not. Hypothesis 3: In the third type, even if country institutions favorFDI, economic factors will not favor domestic investments. Therefore, FDI outflows occur in large amounts. Methods: Data come from open sources of the World Bank, the Fraser Institute, the Heritage Foundation, and other reliable sources. The dependent variable is FDI inflows. The independent variables are institutions (economic and political freedom indices) and economic factors (natural, material, and labor resources, government consumption, infrastructure, minimum wage, education, unemployment, tax rates, consumer price index, inflation, and others), the endogeneity or exogeneity of which are tested in the instrumental variable estimation. Political rights and civil liberties are used as instrumental variables. Results indicate that in the first type, both country institutions and economic factors, specifically labor and logistics/infrastructure/energy intensity, are favorable for potential investors. In the second category of countries, the risk of loss of assets is very high due to governmentshijacked by local oligarchs/cartels/special interest groups. In the third category of countries, the local economic factors are unfavorable for domestic investment even if the institutions are well acceptable. Cluster analysis and instrumental variable estimation were used to reveal cause-effect patterns in each of the clusters.

Keywords: foreign direct investment, economy, institutions, instrumental variable estimation

Procedia PDF Downloads 159

Authors: M. Beusink, E. W. C. Coenen

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The increased application of novel structural materials, such as high grade asphalt, concrete and laminated composites, has sparked the need for a better understanding of the often complex, non-linear mechanical behavior of such materials. The effective macroscopic mechanical response is generally dependent on the applied load path. Moreover, it is also significantly influenced by the microstructure of the material, e.g. embedded fibers, voids and/or grain morphology. At present, multiscale techniques are widely adopted to assess micro-macro interactions in a numerically efficient way. Computational homogenization techniques have been successfully applied over a wide range of engineering cases, e.g. cases involving first order and second order continua, thin shells and cohesive zone models. Most of these homogenization methods rely on Representative Volume Elements (RVE), which model the relevant microstructural details in a confined volume. Imposed through kinematical constraints or boundary conditions, a RVE can be subjected to a microscopic load sequence. This provides the RVE's effective stress-strain response, which can serve as constitutive input for macroscale analyses. Simultaneously, such a study of a RVE gives insight into fine scale phenomena such as microstructural damage and its evolution. It has been reported by several authors that the type of boundary conditions applied to the RVE affect the resulting homogenized stress-strain response. As a consequence, dedicated boundary conditions have been proposed to appropriately deal with this concern. For the specific case of a planar assumption for the analyzed structure, e.g. plane strain, axisymmetric or plane stress, this assumption needs to be addressed consistently in all considered scales. Although in many multiscale studies a planar condition has been employed, the related impact on the multiscale solution has not been explicitly investigated. This work therefore focuses on the influence of the planar assumption for multiscale modeling. In particular the plane stress case is highlighted, by proposing three different implementation strategies which are compatible with a first-order computational homogenization framework. The first method consists of applying classical plane stress theory at the microscale, whereas with the second method a generalized plane stress condition is assumed at the RVE level. For the third method, the plane stress condition is applied at the macroscale by requiring that the resulting macroscopic out-of-plane forces are equal to zero. These strategies are assessed through a numerical study of a thin walled structure and the resulting effective macroscale stress-strain response is compared. It is shown that there is a clear influence of the length scale at which the planar condition is applied.

Keywords: first-order computational homogenization, planar analysis, multiscale, microstrucutures

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Authors: Esraa A. Khalil, Mohamed N. AbouZeid

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Building materials selection is critical for the sustainability of any project. The choice of building materials has a huge impact on the built environment and cost of projects. Building materials emit huge amount of carbon dioxide (CO₂) due to the use of cement as a basic component in the manufacturing process and as a binder, which harms our environment. Energy consumption from buildings has increased in the last few years; a huge amount of energy is being wasted from using unsustainable building and finishing materials, as well as from the process of heating and cooling of buildings. In addition, the construction sector in Egypt is taking a good portion of the economy; however, there is a lack of awareness of buildings environmental impacts on the built environment. Using advanced building materials and different wall systems can help in reducing heat consumption, the project’s initial and long-term costs, and minimizing the environmental impacts. Red Bricks is one of the materials that are being used widely in Egypt. There are many other types of bricks such as Autoclaved Aerated Concrete (AAC); however, the use of Red Bricks is dominating the construction industry due to its affordability and availability. This research focuses on the New Egyptian Administrative Capital as a case study to investigate the potential of the influence of using different wall systems such as AAC on the project’s cost and the environment. The aim of this research is to conduct a comparative analysis between the traditional and most commonly used bricks in Egypt, which is Red Bricks, and AAC wall systems. Through an economic and environmental study, the difference between the two wall systems will be justified to encourage the utilization of uncommon techniques in the construction industry to build more affordable, energy efficient and sustainable buildings. The significance of this research is to show the potential of using AAC in the construction industry and its positive influences. The study analyzes the factors associated with choosing suitable building materials for different projects according to the need and criteria of each project and its nature without harming the environment and wasting materials that could be saved or recycled. The New Egyptian Administrative Capital is considered as the country’s new heart, where ideas regarding energy savings and environmental benefits are taken into consideration. Meaning that, Egypt is taking good steps to move towards more sustainable construction. According to the analysis and site visits, there is a potential in reducing the initial costs of buildings by 12.1% and saving energy by using different techniques up to 25%. Interviews with the mega structures project engineers and managers reveal that they are more open to introducing sustainable building materials that will help in saving the environment and moving towards green construction as well as to studying more effective techniques for energy conservation.

Keywords: AAC blocks, building material, environmental impact, modern construction, new Egyptian administrative capital

Procedia PDF Downloads 120

Authors: Marc Romero-Estonllo, Judith Ramos-Castro, Yaiza San Miguel, Beatriz Rodríguez-Garrido, Carmela Monterroso

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Mining activity is among the main sources of trace and heavy metal(loid) pollution worldwide, which is a hazard to human and environmental health. That is why several projects have been emerging for the remediation of such polluted places. Phytomanagement strategies draw good performances besides big side benefits. In this work, a glasshouse assay with trace element polluted soils from an old Cu mine ore (NW of Spain) which forms part of the PhytoSUDOE network of phytomanaged contaminated field sites (PhytoSUDOE Project (SOE1/P5/E0189)) was set. The objective was to evaluate improvements induced by the following phytoremediation-related treatments. Three increasingly complex amendments alone or together with plant growth (Populus nigra L. alone and together with Tripholium repens L.) were tested. And three different rhizosphere bioinocula were applied (Plant Growth Promoting Bacteria (PGP), mycorrhiza (MYC), or mixed (PGP+MYC)). After 110 days of growth, plants were collected, biomass was weighed, and tree length was measured. Physical-chemical analyses were carried out to determine pH, effective Cation Exchange Capacity, carbon and nitrogen contents, bioavailable phosphorous (Olsen bicarbonate method), pseudo total element content (microwave acid digested fraction), EDTA extractable metals (complexed fraction), and NH4NO3 extractable metals (easily bioavailable fraction). On plant material, nitrogen content and acid digestion elements were determined. Amendment usage, plant growth, and bioinoculation were demonstrated to improve soil fertility and/or plant health within the time span of this study. Particularly, pH levels increased from 3 (highly acidic) to 5 (acidic) in the worst-case scenario, even reaching 7 (neutrality) in the best plots. Organic matter and pH increments were related to polluting metals’ bioavailability decrements. Plants grew better both with the most complex amendment and the middle one, with few differences due to bioinoculation. Using the less complex amendment (just compost) beneficial effects of bioinoculants were more observable, although plants didn’t thrive very well. On unamended soils, plants neither sprouted nor bloomed. The scheme assayed in this study is suitable for phytomanagement of these kinds of soils affected by mining activity. These findings should be tested now on a larger scale.

Keywords: aided phytoremediation, mine pollution, phytostabilization, soil pollution, trace elements

Procedia PDF Downloads 65

Authors: Andrey A. Lipovskii, Alexey V. Redkov, Vyacheslav V. Rusan, Dmitry K. Tagantsev, Valentina V. Zhurikhina

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The presented research is related to the development of recently proposed technique of the formation of composite materials, like optical glass-ceramics, with predetermined structure and properties of the crystalline component. The technique is based on the control of the size and concentration of the crystalline grains using the phenomenon of glass-ceramics decrystallization (vitrification) induced by ion-exchange. This phenomenon was discovered and explained in the beginning of the 2000s, while related theoretical description was given in 2016 only. In general, the developed theory enables one to model the process and optimize the conditions of ion-exchange processing of glass-ceramics, which provide given properties of crystalline component, in particular, profile of the average size of the crystalline grains. The optimization is possible if one knows two dimensionless parameters of the theoretical model. One of them (β) is the value which is directly related to the solubility of crystalline component of the glass-ceramics in the glass matrix, and another (γ) is equal to the ratio of characteristic times of ion-exchange diffusion and crystalline grain dissolution. The presented study is dedicated to the development of experimental technique and simulation which allow determining these parameters. It is shown that these parameters can be deduced from the data on the space distributions of diffusant concentrations and average size of crystalline grains in the glass-ceramics samples subjected to ion-exchange treatment. Measurements at least at two temperatures and two processing times at each temperature are necessary. The composite material used was a silica-based glass-ceramics with crystalline grains of Li2OSiO2. Cubical samples of the glass-ceramics (6x6x6 mm3) underwent the ion exchange process in NaNO3 salt melt at 520 oC (for 16 and 48 h), 540 oC (for 8 and 24 h), 560 oC (for 4 and 12 h), and 580 oC (for 2 and 8 h). The ion exchange processing resulted in the glass-ceramics vitrification in the subsurface layers where ion-exchange diffusion took place. Slabs about 1 mm thick were cut from the central part of the samples and their big facets were polished. These slabs were used to find profiles of diffusant concentrations and average size of the crystalline grains. The concentration profiles were determined from refractive index profiles measured with Max-Zender interferometer, and profiles of the average size of the crystalline grains were determined with micro-Raman spectroscopy. Numerical simulation were based on the developed theoretical model of the glass-ceramics decrystallization induced by ion exchange. The simulation of the processes was carried out for different values of β and γ parameters under all above-mentioned ion exchange conditions. As a result, the temperature dependences of the parameters, which provided a reliable coincidence of the simulation and experimental data, were found. This ensured the adequate modeling of the process of the glass-ceramics decrystallization in 520-580 oC temperature interval. Developed approach provides a powerful tool for fine tuning of the glass-ceramics structure, namely, concentration and average size of crystalline grains.

Keywords: diffusion, glass-ceramics, ion exchange, vitrification

Procedia PDF Downloads 269

Authors: L. Kutateldze, T. Urushadze, R. Khvedelidze, N. Zakariashvili, I. Khokhashvili, T. Sadunishvili

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Microbial cellulase/xylanase have shown their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing, and agriculture. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Representatives of the genera Aspergillus, Penicillium and Trichoderma are outstanding by relatively high activities of these enzymes. Among the producers were revealed thermophilic strains, representatives of the genus Aspergillus-Aspergillus terreus, Aspergillus versicolor, Aspergillus wentii, also strains of Sporotrichum pulverulentum and Chaetomium thermophile. As a result of optimization of cultivation media and conditions, activities of enzymes produced by the strains have been increased by 4 -189 %. Two strains, active producers of cellulase/xylanase – Penicillium canescence E2 (mesophile) and Aspergillus versicolor Z17 (thermophile) were chosen for further studies. Cellulase/xylanase enzyme preparations from two different genera of microscopic fungi Penicillium canescence E2 and Aspergillus versicolor Z 17 were obtained with activities 220 U/g /1200 U/g and 125 U/g /940 U/g, correspondingly. Main technical characteristics were as follows: the highest enzyme activities were obtained for mesophilic strain Penicillium canescence E2 at 45-500C, while almost the same enzyme activities were fixed for the thermophilic strain Aspergillus versicolor Z 17 at temperature 60-65°C, exceeding the temperature optimum of the mesophile by 150C. Optimum pH of action of the studied cellulase/xylanases from mesophileic and thermophilic strains were similar and equaled to 4.5-5.0 It has been shown that cellulase/xylanase technical preparations from selected strains of Penicillium canescence E2 and Aspergillus versicolor Z17 hydrolyzed cellulose of untreated wheat straw to reducible sugars by 46-52%, and to glucose by 22-27%. However the thermophilic enzyme preparations from the thermophilic A.versicolor strains conducted the process at 600C higher by 100C as compared to mesophlic analogue. Rate of hydrolyses of the pretreated substrate by the same enzyme preparations to reducible sugars and glucose conducted at optimum for their action 60 and 500C was 52-61% and 29-33%, correspondingly. Thus, maximum yield of glucose and reducible sugars form untreated and pretreated wheat straw was achieved at higher temperature (600C) by enzyme preparations from thermophilic strain, which gives advantage for their industrial application.

Keywords: cellulase/xylanase, cellulose hydrolysis, microscopic fungi, thermophilic strain

Procedia PDF Downloads 284

Authors: Burçak Boztemur, Yue Xu, Laima Luo, M. Lütfi Öveçoğlu, Duygu Ağaoğulları

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Tungsten (W) is used chiefly as plasma-facing material. However, it has some problems, such as brittleness after plasma exposure. High-entropy alloys (RHEAs) are a new opportunity for this deficiency. So, the neutron shielding behavior of WNbMoVTa and WNbMoVTaCr₀.₅Al compositions were examined against He⁺ irradiation in this study. The mechanical and irradiation properties of the WNbMoVTa base composition were investigated by adding the Al and Cr elements. The mechanical alloying (MA) for 6 hours was applied to obtain RHEA powders. According to the X-ray diffraction (XRD) method, the body-centered cubic (BCC) phase and NbTa phase with a small amount of WC impurity that comes from vials and balls were determined after 6 h MA. Also, RHEA powders were consolidated with the spark plasma sintering (SPS) method (1500 ºC, 30 MPa, and 10 min). After the SPS method, (Nb,Ta)C and W₂C₀.₈₅ phases were obtained with the decomposition of WC and stearic acid that is added during MA based on XRD results. Also, the BCC phase was obtained for both samples. While the Al₂O₃ phase with a small intensity was seen for the WNbMoVTaCr₀.₅Al sample, the Ta₂VO₆ phase was determined for the base sample. These phases were observed as three different regions according to scanning electron microscopy (SEM). All elements were distributed homogeneously on the white region by measuring an electron probe micro-analyzer (EPMA) coupled with a wavelength dispersive spectroscope (WDS). Also, the grey region of the WNbMoVTa sample was rich in Ta, V, and O elements. However, the amount of Al and O elements was higher for the grey region of the WNbMoVTaCr₀.₅Al sample. The high amount of Nb, Ta, and C elements were determined for both samples. Archimedes’ densities that were measured with alcohol media were closer to the theoretical densities of RHEAs. These values were important for the microhardness and irradiation resistance of compositions. While the Vickers microhardness value of the WNbMoVTa sample was measured as ~11 GPa, this value increased to nearly 13 GPa with the WNbMoVTaCr₀.₅Al sample. These values were compatible with the wear behavior. The wear volume loss was decreased to 0.16×10⁻⁴ from 1.25×10⁻⁴ mm³ by the addition of Al and Cr elements to the WNbMoVTa. The He⁺ irradiation was conducted on the samples to observe surface damage. After irradiation, the XRD patterns were shifted to the left because of defects and dislocations. He⁺ ions were infused under the surface, so they created the lattice expansion. The peak shifting of the WNbMoVTaCr₀.₅Al sample was less than the WNbMoVTa base sample, thanks to less impact. A small amount of fuzz was observed for the base sample. This structure was removed and transformed into a wavy structure with the addition of Cr and Al elements. Also, the deformation hardening was actualized after irradiation. A lower amount of hardening was obtained with the WNbMoVTaCr₀.₅Al sample based on the changing microhardness values. The surface deformation was decreased in the WNbMoVTaCr₀.₅Al sample.

Keywords: refractory high entropy alloy, microhardness, wear resistance, He⁺ irradiation

Procedia PDF Downloads 64

Authors: Paulette Henry

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If Caribbean Universities wish to remain sustainable in the global education market they must meet the new demands of the 21st Centuries learners. This means preparing the teaching and learning environment with the human and material and resources so that the University can blossom out into the entrepreneurial University. The entrepreneurial University prepares the learner to become a global citizen, one who is innovative and a critical thinker and has the competencies to create jobs. Entrepreneurship education provides more equitable access to university education building capacity for the local and global economy. The entrepreneurial thinking, the mindset, must therefore be among academic and support staff as well as students. In developing countries where resources are scarce, Universities are grappling with a myriad of financial and non-financial issues. These include increasing costs, Union demands for increased remuneration for staff and reduced subvention from governments which has become the norm. In addition, there is the political pressure against increasing tuition fees and the perceptions on the moral responsibilities of universities in national development. The question is how do small universities carve out their niche, meet both political and consumer demands for a high quality, low lost education, fulfil their development mandate and still remain not only viable but competitive. Themes which are central to this discourse on the transitions necessary for the entrepreneurial university are leadership, governance and staff well-being. This paper therefore presents a case study of a Caribbean University to show how transformational leadership and the change management framework propels change towards an entrepreneurial institution seeking to have a competitive advantage despite its low resourced context. Important to this discourse are the transformational approaches used by the University to prepare staff to move from their traditional psyche to embracing an entrepreneurial mindset whilst equipping students within the same mode to become work ready and creative global citizens. Using the mixed methods approach, opinions were garnered from both members of the University community as well as external stakeholder groups on their perception of the role of the University in the business arena and as a primary stakeholder in national development. One of the critical concepts emanating from the discourse was the need to change the mindset of the those in university governance as well as how national stakeholders engage the university. This paper shows how multiple non-financial factors can contribute to change. A combination of transformational and servant leadership, strengthened institutional structures and developing new ones, rebuilding institutional trust and pride have been among the strategies employed within the change management framework. The university is no longer limited by borders but through international linkages has transcended into a transnational stakeholder.

Keywords: competitiveness, context, entrepreneurial, leadership

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Authors: Stefano Iannello, Massimiliano Materazzi

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Fluidized bed reactor technologies are one of the most valuable pathways for thermochemical conversions of biogenic fuels due to their good operating flexibility. Nevertheless, there are still issues related to the mixing and separation of heterogeneous phases during operation with highly volatile feedstocks, including biomass and waste. At high temperatures, the volatile content of the feedstock is released in the form of the so-called endogenous bubbles, which generally exert a “lift” effect on the particle itself by dragging it up to the bed surface. Such phenomenon leads to high release of volatile matter into the freeboard and limited mass and heat transfer with particles of the bed inventory. The aim of this work is to get a better understanding of the behaviour of a single reacting particle in a hot fluidized bed reactor during the devolatilization stage. The analysis has been undertaken at different fluidization regimes and temperatures to closely mirror the operating conditions of waste-to-energy processes. Beechwood and polypropylene particles were used to resemble the biomass and plastic fractions present in waste materials, respectively. The non-invasive X-ray technique was coupled to particle tracking algorithms to characterize the motion of a single feedstock particle during the devolatilization with high resolution. A high-energy X-ray beam passes through the vessel where absorption occurs, depending on the distribution and amount of solids and fluids along the beam path. A high-speed video camera is synchronised to the beam and provides frame-by-frame imaging of the flow patterns of fluids and solids within the fluidized bed up to 72 fps (frames per second). A comprehensive mathematical model has been developed in order to validate the experimental results. Beech wood and polypropylene particles have shown a very different dynamic behaviour during the pyrolysis stage. When the feedstock is fed from the bottom, the plastic material tends to spend more time within the bed than the biomass. This behaviour can be attributed to the presence of the endogenous bubbles, which drag effect is more pronounced during the devolatilization of biomass, resulting in a lower residence time of the particle within the bed. At the typical operating temperatures of thermochemical conversions, the synthetic polymer softens and melts, and the bed particles attach on its outer surface, generating a wet plastic-sand agglomerate. Consequently, this additional layer of sand may hinder the rapid evolution of volatiles in the form of endogenous bubbles, and therefore the establishment of a poor drag effect acting on the feedstock itself. Information about the mixing and segregation of solid feedstock is of prime importance for the design and development of more efficient industrial-scale operations.

Keywords: fluidized bed, pyrolysis, waste feedstock, X-ray

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Authors: Claude Nsobya, Alice Moncaster, Karen Potter, Jed Ramsay

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The shift in Flood Risk Governance (FRG) has moved away from traditional approaches that solely relied on centralized decision-making and structural flood defenses. Instead, there is now the adoption of integrated flood risk management measures that involve various actors and stakeholders. This new approach emphasizes people-centered approaches, including adaptation and learning. This shift to a diversity of FRG approaches has been identified as a significant factor in enhancing resilience. Resilience here refers to a community's ability to withstand, absorb, recover, adapt, and potentially transform in the face of flood events. It is argued that if the FRG merely focused on the conventional 'fighting the water' - flood defense - communities would not be resilient. The move to these people-centered approaches also implies that communities will be more involved in FRG. It is suggested that effective flood risk governance influences resilience through meaningful community involvement, and effective community engagement is vital in shaping community resilience to floods. Successful community participation not only uses context-specific indigenous knowledge but also develops a sense of ownership and responsibility. Through capacity development initiatives, it can also raise awareness and all these help in building resilience. Recent Flood Risk Management (FRM) projects have thus had increasing community involvement, with varied conceptualizations of such community engagement in the academic literature on FRM. In the context of overland floods, there has been a substantial body of literature on Flood Risk Governance and Management. Yet, groundwater flooding has gotten little attention despite its unique qualities, such as its persistence for weeks or months, slow onset, and near-invisibility. There has been a little study in this area on how successful community involvement in Flood Risk Governance may improve community resilience to groundwater flooding in particular. This paper focuses on a case study of a flood risk management project in the United Kingdom. Buckinghamshire Council is leading Project Groundwater, which is one of 25 significant initiatives sponsored by England's Department for Environment, Food and Rural Affairs (DEFRA) Flood and Coastal Resilience Innovation Programme. DEFRA awarded Buckinghamshire Council and other councils 150 million to collaborate with communities and implement innovative methods to increase resilience to groundwater flooding. Based on a literature review, this paper proposes a new paradigm for effective community engagement in Flood Risk Governance (FRG). This study contends that effective community participation can have an impact on various resilience capacities identified in the literature, including social capital, institutional capital, physical capital, natural capital, human capital, and economic capital. In the case of social capital, for example, successful community engagement can influence social capital through the process of social learning as well as through developing social networks and trust values, which are vital in influencing communities' capacity to resist, absorb, recover, and adapt. The study examines community engagement in Project Groundwater using surveys with local communities and documentary analysis to test this notion. The outcomes of the study will inform community involvement activities in Project Groundwater and may shape DEFRA policies and guidelines for community engagement in FRM.

Keywords: flood risk governance, community, resilience, groundwater flooding

Procedia PDF Downloads 69

Authors: Hyemi Kim, Jay Kim, Kyunghoon Han, Ra-Yeong Choi, In-Woo Kim, Hyung Joo Suh, Ki-Bae Hong, Sung Hee Han

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Chitosan is used in various industries such as food and medical care because it is known to have various functions such as anti-obesity, anti-inflammatory and anti-cancer benefits. Most of the commercial chitosan is extracted from crustaceans. As the harvest rate of snow crabs and red snow crabs decreases and safety issues arise due to environmental pollution, research is underway to extract chitosan from insects. In this study, we used Response Surface Methodology (RSM) to predict the optimal conditions to produce chitosan oligosaccharides from mealworms (MCOS), which can be absorbed through the intestine as low-molecular-weight chitosan. The experimentally confirmed optimal conditions for MCOS production using chitosanase were found to be a substrate concentration of 2.5%, enzyme addition of 30 mg/g and a reaction time of 6 hours. The chemical structure and physicochemical properties of the produced MCOS were measured using MALDI-TOF mass spectra and FTIR spectra. The MALDI-TOF mass spectra revealed peaks corresponding to the dimer (375.045), trimer (525.214), tetramer (693.243), pentamer (826.296), and hexamer (987.360). In the FTIR spectra, commercial chitosan oligosaccharides exhibited a weak peak pattern at 3500-2500 cm-1, unlike chitosan or chitosan oligosaccharides. There was a difference in the peak at 3200~3500 cm-1, where different vibrations corresponding to OH and amine groups overlapped. Chitosan, chitosan oligosaccharide, and commercial chitosan oligosaccharide showed peaks at 2849, 2884, and 2885 cm-1, respectively, attributed to the absorption of the C-H stretching vibration of methyl or methine. The amide I, amide II, and amide III bands of chitosan, chitosan oligosaccharide, and commercial chitosan oligosaccharide exhibited peaks at 1620/1620/1602, 1553/1555/1505, and 1310/1309/1317 cm-1, respectively. Furthermore, the solubility of MCOS was 45.15±3.43, water binding capacity (WBC) was 299.25±4.57, and fat binding capacity (FBC) was 325.61±2.28 and the solubility of commercial chitosan oligosaccharides was 49.04±9.52, WBC was 280.55±0.50, and FBC was 157.22±18.15. Thus, the characteristics of MCOS and commercial chitosan oligosaccharides are similar. The results of investigating the impact of chitosan oligosaccharide on the proliferation of probiotics revealed increased growth in L. casei, L. acidophilus, and Bif. Bifidum. Therefore, the major short-chain fatty acids produced by gut microorganisms, such as acetic acid, propionic acid, and butyric acid, increased within 24 hours of adding 1% (p<0.01) and 2% (p<0.001) MCOS. The impact of MCOS on the overall gut microbiota was assessed, revealing that the Chao1 index did not show significant differences, but the Simpson index decreased in a concentration-dependent manner, indicating a higher species diversity. The addition of MCOS resulted in changes in the overall microbial composition, with an increase in Firmicutes and Verrucomicrobia (p<0.05) compared to the control group, while Proteobacteria and Actinobacteria (p<0.05) decreased. At the genus level, changes in microbiota due to MCOS supplementation showed an increase in beneficial bacteria like lactobacillus, Romboutsia, Turicibacter, and Akkermansia (p<0.0001) while harmful bacteria like Enterococcus, Morganella, Proterus, and Bacteroides (p<0.0001) decreased. In this study, chitosan oligosaccharides were successfully produced under established conditions from mealworms, and these chitosan oligosaccharides are expected to have prebiotic effects, similar to those obtained from crabs.

Keywords: mealworms, chitosan, chitosan oligosaccharide, prebiotics

Procedia PDF Downloads 63

Authors: Görkem Cemali̇, Avram Aruh, Gamze Torun Köse, Erde Can ŞAfak

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In order to heal bone disorders, the conventional methods which involve the use of autologous and allogenous bone grafts or permanent implants have certain disadvantages such as limited supply, disease transmission, or adverse immune response. A biodegradable material that acts as structural support to the damaged bone area and serves as a scaffold that enhances bone regeneration and guides bone formation is one desirable solution. Poly(propylene fumarate) (PPF) which is an unsaturated polyester that can be copolymerized with appropriate vinyl monomers to give biodegradable network structures, is a promising candidate polymer to prepare bone tissue engineering scaffolds. In this study, hydroxyl-terminated PPF was synthesized and thermally cured with vinyl phosphonic acid (VPA) and diethyl vinyl phosphonate (VPES) in the presence of radical initiator benzoyl peroxide (BP), with changing co-monomer weight ratios (10-40wt%). In addition, the synthesized PPF was cured with VPES comonomer at body temperature (37oC) in the presence of BP initiator, N, N-Dimethyl para-toluidine catalyst and varying amounts of Beta-tricalcium phosphate (0-20 wt% ß-TCP) as filler via radical polymerization to prepare composite materials that can be used in injectable forms. Thermomechanical properties, compressive properties, hydrophilicity and biodegradability of the PPF/VPA and PPF/VPES copolymers were determined and analyzed with respect to the copolymer composition. Biocompatibility of the resulting polymers and their composites was determined by the MTS assay and osteoblast activity was explored with von kossa, alkaline phosphatase and osteocalcin activity analysis and the effects of VPA and VPES comonomer composition on these properties were investigated. Thermally cured PPF/VPA and PPF/VPES copolymers with different compositions exhibited compressive modulus and strength values in the wide range of 10–836 MPa and 14–119 MPa, respectively. MTS assay studies showed that the majority of the tested compositions were biocompatible and the overall results indicated that PPF/VPA and PPF/VPES network polymers show significant potential for applications as bone tissue engineering scaffolds where varying PPF and co-monomer ratio provides adjustable and controllable properties of the end product. The body temperature cured PPF/VPES/ß-TCP composites exhibited significantly lower compressive modulus and strength values than the thermal cured PPF/VPES copolymers and were therefore found to be useful as scaffolds for cartilage tissue engineering applications.

Keywords: biodegradable, bone tissue, copolymer, poly(propylene fumarate), scaffold

Procedia PDF Downloads 165

Authors: Asad Hanif, Pavithra Parthasarathy, Zongjin Li

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Thermal insulating composites help to reduce the total power consumption in a building by creating a barrier between external and internal environment. Such composites can be used in the roofing tiles or wall panels for exterior surfaces. This study purposes to develop lightweight cement-based composites for thermal insulating applications. Waste materials like silica fume (an industrial by-product) and fly ash cenosphere (FAC) (hollow micro-spherical shells obtained as a waste residue from coal fired power plants) were used as partial replacement of cement and lightweight filler, respectively. Moreover, aerogel, a nano-porous material made of silica, was also used in different dosages for improved thermal insulating behavior, while poly vinyl alcohol (PVA) fibers were added for enhanced toughness. The raw materials including binders and fillers were characterized by X-Ray Diffraction (XRD), X-Ray Fluorescence spectroscopy (XRF), and Brunauer–Emmett–Teller (BET) analysis techniques in which various physical and chemical properties of the raw materials were evaluated like specific surface area, chemical composition (oxide form), and pore size distribution (if any). Ultra-lightweight cementitious composites were developed by varying the amounts of FAC and aerogel with 28-day unit weight ranging from 1551.28 kg/m³ to 1027.85 kg/m³. Excellent mechanical and thermal insulating properties of the resulting composites were obtained ranging from 53.62 MPa to 8.66 MPa compressive strength, 9.77 MPa to 3.98 MPa flexural strength, and 0.3025 W/m-K to 0.2009 W/m-K as thermal conductivity coefficient (QTM-500). The composites were also tested for peak temperature difference between outer and inner surfaces when subjected to heating (in a specially designed experimental set-up) by a 275W infrared lamp. The temperature difference up to 16.78 ^oC was achieved, which indicated outstanding properties of the developed composites to act as a thermal barrier for building envelopes. Microstructural studies were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) for characterizing the inner structure of the composite specimen. Also, the hydration products were quantified using the surface area mapping and line scale technique in EDS. The microstructural analyses indicated excellent bonding of FAC and aerogel in the cementitious system. Also, selective reactivity of FAC was ascertained from the SEM imagery where the partially consumed FAC shells were observed. All in all, the lightweight fillers, FAC, and aerogel helped to produce the lightweight composites due to their physical characteristics, while exceptional mechanical properties, owing to FAC partial reactivity, were achieved.

Keywords: aerogel, cement-based, composite, fly ash cenosphere, lightweight, sustainable development, thermal conductivity

Procedia PDF Downloads 222

Authors: Milica Carević, Katarina Banjanac, Marija ĆOrović, Ana Milivojević, Nevena Prlainović, Aleksandar Marinković, Dejan Bezbradica

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Nowadays, considering the growing awareness of functional food beneficial effects on human health, due attention is dedicated to the research in the field of obtaining new prominent products exhibiting improved physiological and physicochemical characteristics. Therefore, different approaches to valuable bioactive compounds synthesis have been proposed. β-Galactosidase, for example, although mainly utilized as hydrolytic enzyme, proved to be a promising tool for these purposes. Namely, under the particular conditions, such as high lactose concentration, elevated temperatures and low water activities, reaction of galactose moiety transfer to free hydroxyl group of the alternative acceptor (e.g. different sugars, alcohols or aromatic compounds) can generate a wide range of potentially interesting products. Up to now, galacto-oligosaccharides and lactulose have attracted the most attention due to their inherent prebiotic properties. The goal of this study was to obtain a novel product sorbitol galactoside, using the similar reaction mechanism, namely transgalactosylation reaction catalyzed by β-galactosidase from Aspergillus oryzae. By using sugar alcohol (sorbitol) as alternative acceptor, a diverse mixture of potential prebiotics is produced, enabling its more favorable functional features. Nevertheless, an introduction of alternative acceptor into the reaction mixture contributed to the complexity of reaction scheme, since several potential reaction pathways were introduced. Therefore, the thorough optimization using response surface method (RSM), in order to get an insight into different parameter (lactose concentration, sorbitol to lactose molar ratio, enzyme concentration, NaCl concentration and reaction time) influences, as well as their mutual interactions on product yield and productivity, was performed. In view of product yield maximization, the obtained model predicted optimal lactose concentration 500 mM, the molar ratio of sobitol to lactose 9, enzyme concentration 0.76 mg/ml, concentration of NaCl 0.8M, and the reaction time 7h. From the aspect of productivity, the optimum substrate molar ratio was found to be 1, while the values for other factors coincide. In order to additionally, improve enzyme efficiency and enable its reuse and potential continual application, immobilization of β-galactosidase onto tailored silica nanoparticles was performed. These non-porous fumed silica nanoparticles (FNS)were chosen on the basis of their biocompatibility and non-toxicity, as well as their advantageous mechanical and hydrodinamical properties. However, in order to achieve better compatibility between enzymes and the carrier, modifications of the silica surface using amino functional organosilane (3-aminopropyltrimethoxysilane, APTMS) were made. Obtained support with amino functional groups (AFNS) enabled high enzyme loadings and, more importantly, extremely high expressed activities, approximately 230 mg proteins/g and 2100 IU/g, respectively. Moreover, this immobilized preparation showed high affinity towards sorbitol galactoside synthesis. Therefore, the findings of this study could provided a valuable contribution to the efficient production of physiologically active galactosides in immobilized enzyme reactors.

Keywords: β-galactosidase, immobilization, silica nanoparticles, transgalactosylation

Procedia PDF Downloads 300

Authors: Haidy Weliam Megaly Gouda

Abstract:

Dermatology is often a neglected specialty in low-resource settings despite the high morbidity associated with skin disease. This becomes even more significant when associated with HIV infection, as dermatological conditions are more common and aggressive in HIV-positive patients. African countries have the highest HIV infection rates, and skin conditions are frequently misdiagnosed and mismanaged because of a lack of dermatological training and educational material. The frequent lack of diagnostic tests in the African setting renders basic clinical skills all the more vital. This project aimed to improve the diagnosis and treatment of skin disease in the HIV population in a district hospital in Malawi. A basic dermatological clinical tool was developed and produced in collaboration with local staff and based on available literature and data collected from clinics. The aim was to improve diagnostic accuracy and provide guidance for the treatment of skin disease in HIV-positive patients. A literature search within Embassy, Medline and Google Scholar was performed and supplemented through data obtained from attending 5 Antiretroviral clinics. From the literature, conditions were selected for inclusion in the resource if they were described as specific, more prevalent, or extensive in the HIV population or have more adverse outcomes if they develop in HIV patients. Resource-appropriate treatment options were decided using Malawian Ministry of Health guidelines and textbooks specific to African dermatology. After the collection of data and discussion with local clinical and pharmacy staff, a list of 15 skin conditions was included, and a booklet was created using the simple layout of a picture, a diagnostic description of the disease and treatment options. Clinical photographs were collected from local clinics (with full consent of the patient) or from the book ‘Common Skin Diseases in Africa’ (permission granted if fully acknowledged and used in a not-for-profit capacity). This tool was evaluated by the local staff alongside an educational teaching session on skin disease. This project aimed to reduce uncertainty in diagnosis and provide guidance for appropriate treatment in HIV patients by gathering information into one practical and manageable resource. To further this project, we hope to review the effectiveness of the tool in practice.

Keywords: prevalence and pattern of skin diseases, impact on quality of life, rural Nepal, interventions, quality switched ruby laser, skin color river blindness, clinical signs, circularity index, grey level run length matrix, grey level co-occurrence matrix, local binary pattern, object detection, ring detection, shape identification

Procedia PDF Downloads 60

Authors: Olga Gomez De Miranda, Jose R. Ochoa-Gomez, Stefaan De Wildeman, Luciano Monsegue, Soraya Prieto, Leire Lorenzo, Cristina Dineiro

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The chemical industry is facing a new revolution. As long as processes based on the exploitation of fossil resources emerged with force in the XIX century, Society currently demands a new radical change that will lead to the complete and irreversible implementation of a circular sustainable economic model. The implementation of biorefineries will be essential for this. There, renewable raw materials as sugars and other biomass resources are exploited for the development of new materials that will partially replace their petroleum-derived homologs in a safer, and environmentally more benign approach. Isosorbide, (1,4:3,6-dianhydro-d-glucidol) is a primary bio-based derivative obtained from the plant (poly) saccharides and a very interesting example of a useful chemical produced in biorefineries. It can, in turn, be converted to other secondary monomers as isosorbide bis-methyl carbonate (IBMC), whose main field of application can be as a key biodegradable intermediary substitute of bisphenol-A in the manufacture of polycarbonates, or as an alternative to the toxic isocyanates in the synthesis of new polyurethanes (non-isocyanate polyurethanes) both with a huge application market. New products will present advantageous mechanical or optical properties, as well as improved behavior in non-toxicity and biodegradability aspects in comparison to their petro-derived alternatives. A robust production process of IBMC, a biomass-derived chemical, is here presented. It can be used with different raw material qualities using dimethyl carbonate (DMC) as both co-reactant and solvent. It consists of the transesterification of isosorbide with DMC under soft operational conditions, using different basic catalysts, always active with the isosorbide characteristics and purity. Appropriate isolation processes have been also developed to obtain crude IBMC yields higher than 90%, with oligomers production lower than 10%, independently of the quality of the isosorbide considered. All of them are suitable to be used in polycondensation reactions for polymers obtaining. If higher qualities of IBMC are needed, a purification treatment based on nanofiltration membranes has been also developed. The IBMC reaction-isolation conditions established in the laboratory have been successfully modeled using appropriate software programs and moved to a pilot-scale (production of 100 kg of IBMC). It has been demonstrated that a highly efficient IBMC production process able to be up-scaled under suitable market conditions has been obtained. Operational conditions involved the production of IBMC involve soft temperature and energy needs, no additional solvents, and high operational efficiency. All of them are according to green manufacturing rules.

Keywords: biomass, catalyst, isosorbide bis-methyl carbonate, polycarbonate, polyurethane, transesterification

Procedia PDF Downloads 130

Authors: Kiyanoush Ghalavand, Ali Ferydooni

Abstract:

Fars province Fārs or Pārs is a vast land located in the southwest of Iran. All over the province, you can see and feel the glory of Ancient Iranian culture and civilization. There are many monuments from pre-historical to the Islamic era within this province. The existence of ancient cultural and historical monuments in Fars province including the historical complex of Persepolis, the tombs of Persian poets Hafez and Saadi, and dozens of other valuable cultural and historical works of this province as a symbol of Iranian national identity and the manifestation of transcendent cultural values of this national identity. Fars province is quintessentially Persian. Its name is the modern version of ancient Parsa, the homeland, if not the place of origin, of the Persians, one of the great powers of antiquity. From here, the Persian Empire ruled much of Western and Central Asia, receiving ambassadors and messengers at Persepolis. It was here that the Persian kings were buried, both in the mountain behind Persepolis and in the rock face of nearby Naqsh-e Rustam. We have a complex paradox in Persian and Islamic ideology in the age of technology in Iran. The main purpose of the present article is to identify and describe the problems and prospects of origin and development of the modern approach to the conservation and restoration of ancient monuments and historic buildings, the influence that this development has had on international collaboration in the protection and conservation of cultural heritage, and the present consequences worldwide. The definition of objects and structures of the past as heritage, and the policies related to their protection, restoration, and conservation, have evolved together with modernity, and are currently recognized as an essential part of the responsibilities of modern society. Since the eighteenth century, the goal of this protection has been defined as the cultural heritage of humanity; gradually this has included not only ancient monuments and past works of art but even entire territories for a variety of new values generated in recent decades. In its medium-term program of 1989, UNESCO defined the full scope of such heritage. The cultural heritage may be defined as the entire corpus of material signs either artistic or symbolic handed on by the past to each culture and, therefore, to the whole of humankind. As a constituent part of the affirmation and enrichment of cultural identities, as a legacy belonging to all humankind, the cultural heritage gives each particular place its recognizable features and is the storehouse of human experience. The preservation and the presentation of the cultural heritage are therefore a corner-stone of any cultural policy. The process, from which these concepts and policies have emerged, has been identified as the ‘modern conservation movement’.

Keywords: tradition, modern, heritage, historical building, protection, cultural policy, fars province

Procedia PDF Downloads 163