Search results for: engineered wood
270 Construction of Genetic Recombinant Yeasts with High Environmental Tolerance by Accumulation of Trehalose and Detoxication of Aldehyde
Authors: Yun-Chin Chung, Nileema Divate, Gen-Hung Chen, Pei-Ru Huang, Rupesh Divate
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Many environmental factors, such as glucose concentration, ethanol, temperature, osmotic pressure and pH, decrease the production rate of ethanol using yeast as a starter. Fermentation starters with high tolerance to various stresses are always demanded for brewing industry. Trehalose, a storage carbohydrate in cell wall of yeast, plays an important role in tolerance of environmental stress by preserving integrity of plasma membrane and stabilizing proteins. Furan aldehydes are toxic to yeast and the growth rate of yeast is significantly reduced if furan aldehydes were present in the fermentation medium. In yeast, aldehyde reductase is involved in the detoxification of reactive aldehydes and consequently the growth of yeast is improved. The aims of this study were to construct a genetic recombinant Saccharomyces cerevisiae or Pichia pastoris with furfural and HMF degrading and high ethanol tolerance capacities. Yeast strains were engineered by genetic recombination for overexpression of trehalose-6-phosphate synthase gene (tps1) and aldehyde reductase gene (ari1). TPS1 gene was cloned from S. cerevisiae by reverse transcription-polymerase chain reaction (RT-PCR) and then ligated with pGAPZαC vector. The constructed vector, pGAPZC-tps1, was transformed to recombinant yeasts strain with overexpression of ari1. The transformants with pGAPZC-tps1-ari1 were generated called STA (S. cerevisiae) and PTA (P. pastoris) with overexpression of tps1, ari1. PCR with tps1-specific primers and western blot with his-tag confirmed the gene insertion and protein expression of tps1 in the transformants, respectively. The neutral trehalase gene (nth1) of STA was successfully deleted and the novel strain STAΔN will be used for further study, including the measurement of trehalose concentration and ethanol, furfural tolerance assay.Keywords: genetic recombinant, yeast, ethanol tolerance, trehalase, aldehyde reductase
Procedia PDF Downloads 422269 Estimation of Carbon Sequestration and Air Quality of Terrestrial Ecosystems Using Remote Sensing Techniques
Authors: Kanwal Javid, Shazia Pervaiz, Maria Mumtaz, Muhammad Ameer Nawaz Akram
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Forests and grasslands ecosystems play an important role in the global carbon cycle. Land management activities influence both ecosystems and enable them to absorb and sequester carbon dioxide (CO2). Similarly, in Pakistan, these terrestrial ecosystems are well known to mitigate carbon emissions and have a great source to supply a variety of services such as clean air and water, biodiversity, wood products, wildlife habitat, food, recreation and carbon sequestration. Carbon sequestration is the main agenda of developed and developing nations to reduce the impacts of global warming. But the amount of carbon storage within these ecosystems can be affected by many factors related to air quality such as land management, land-use change, deforestation, over grazing and natural calamities. Moreover, the long-term capacity of forests and grasslands to absorb and sequester CO2 depends on their health, productivity, resilience and ability to adapt to changing conditions. Thus, the main rationale of this study is to monitor the difference in carbon amount of forests and grasslands of Northern Pakistan using MODIS data sets and map results using Geographic Information System. Results of the study conclude that forests ecosystems are more effective in reducing the CO2 level and play a key role in improving the quality of air.Keywords: carbon sequestration, grasslands, global warming, climate change.
Procedia PDF Downloads 187268 Sulfate Reducing Bacteria Based Bio-Electrochemical System: Towards Sustainable Landfill Leachate and Solid Waste Treatment
Authors: K. Sushma Varma, Rajesh Singh
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Non-engineered landfills cause serious environmental damage due to toxic emissions and mobilization of persistent pollutants, organic and inorganic contaminants, as well as soluble metal ions. The available treatment technologies for landfill leachate and solid waste are not effective from an economic, environmental, and social standpoint. The present study assesses the potential of the bioelectrochemical system (BES) integrated with sulfate-reducing bacteria (SRB) in the sustainable treatment and decontamination of landfill wastes. For this purpose, solid waste and landfill leachate collected from different landfill sites were evaluated for long-term treatment using the integrated SRB-BES anaerobic designed bioreactors after pre-treatment. Based on periodic gas composition analysis, physicochemical characterization of the leachate and solid waste, and metal concentration determination, the present system demonstrated significant improvement in volumetric hydrogen production by suppressing methanogenesis. High reduction percentages of Be, Cr, Pb, Cd, Sb, Ni, Cr, COD, and sTOC removal were observed. This mineralization can be attributed to the synergistic effect of ammonia-assisted pre-treatment complexation and microbial sulphide formation. Despite being amended with 0.1N ammonia, the treated leachate level of NO³⁻ was found to be reduced along with SO₄²⁻. This integrated SRB-BES system can be recommended as an eco-friendly solution for landfill reclamation. The BES-treated solid waste was evidently more stabilized, as shown by a five-fold increase in surface area, and potentially useful for leachate immobilization and bio-fortification of agricultural fields. The vector arrangement and magnitude showed similar treatment with differences in magnitudes for both leachate and solid waste. These findings support the efficacy of SRB-BES in the treatment of landfill leachate and solid waste sustainably, inching a step closer to our sustainable development goals. It utilizes low-cost treatment, and anaerobic SRB adapted to landfill sites. This technology may prove to be a sustainable treatment strategy upon scaling up as its outcomes are two-pronged: landfill waste treatment and energy recovery.Keywords: bio-electrochemical system, leachate /solid waste treatment, landfill leachate, sulfate-reducing bacteria
Procedia PDF Downloads 102267 Investigation of Mode II Fracture Toughness in Orthotropic Materials
Authors: Mahdi Fakoor, Nabi Mehri Khansari, Ahmadreza Farokhi
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Evaluation of mode II fracture toughness (KIIC) in composite materials is very hard problem to be solved, since it can be affected by many mechanisms of dissipation. Furthermore, non-linearity in its behavior can offer an extra difficulty to obtain accuracy in the results. Different reported values for KIIC in various references can prove the mentioned assertion. In this research, some solutions proposed based on the form of necessary corrections that should be executed on the common test fixtures. Due to the fact that the common test fixtures are not able to active toughening mechanisms in pure Mode II correctly, we have employed some structural modifications on common fixtures. Particularly, the Iosipescu test is used as start point. The tests are applied on graphite/epoxy; PMMA and Western White Pine Wood. Also, mixed mode I/II fracture limit curves are used to indicate the scattering in test results are really relevant to the creation of Fracture Process Zone (FPZ). In the present paper, shear load consideration applied at the predicted shear zone by considering some significant structural amendments that can active mode II toughening mechanisms. Indeed, the employed empirical method causes significant developing in repeatability and reproducibility as well. Moreover, a 3D Finite Element (FE) is performed for verification of the obtained results. Eventually, it is figured out that, a remarkable precision can be obtained in common test fixture in comparison with the previous one.Keywords: FPZ, shear test fixture, mode II fracture toughness, composite material, FEM
Procedia PDF Downloads 361266 Development and Characterization of Polymorphic Genomic-SSR Markers in Asian Long-Horned Beetle (Anoplophora glabripennis)
Authors: Zhao Yang Liu, Jing Tao
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The Asian long-horned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae: Lamiinae), is a wood-borer and polyphagous xylophages native to Asia and killing healthy trees. As it causes serious danger to trees, the beetle has been paid close attention in the world. However, the genetic markers limited, especially microsatellite. In this study, 24 novel simple sequence repeat (SSR) molecular markers, a powerful tool for genetic diversity studies and linkage map construction, were developed and characterized from whole genome shotgun sequences. We developed SSR loci of 2 to 6 repeated and perfect units including 9895 points, the density of SSRs was found one SSR per 56.57 kb and the abundance of SSR was 0.02/kb, besides 140 types of repeats motifs were found. Half of the 48 pairs SSR primers (containing 4 di-, 7 tri-, 2 tetra- and 11 hexamers SSRs) we selected randomly from 1222 pairs of primers were polymorphism. The number of alleles for these markers in 48 individuals varied from 3 to 21 with an average of 7.71, the number of effective alleles ranged from 1.22 to 9.97 with an average of 3.54. Besides this, the polymorphic information content (PIC) ranged from 0.18 to 0.89 with a mean of 0.65, And Shannon's Information index (I) ranged from 0.46 to 2.62 with an average of 1.44. The results suggest that the method for screening of SSR in the whole genome is feasible and efficient. SSR markers developed in this study can be used for population genetic studies of A. glabripennis. Moreover, they may also be helpful for the development of microsatellites for other Coleoptera.Keywords: SSR markers, Anoplophora glabripennis, genetic diversity, whole genome
Procedia PDF Downloads 389265 Analysis of Construction Waste Generation and Its Effect in a Construction Site
Authors: R. K. D. G. Kaluarachchi
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The generation of solid waste and its effective management are debated topics in Sri Lanka as well as in the global environment. It was estimated that the most of the waste generated in global was originated from construction and demolition of buildings. Thus, the proportion of construction waste in solid waste generation cannot be underestimated. The construction waste, which is the by-product generated and removed from work sites is collected in direct and indirect processes. Hence, the objectives of this research are to identify the proportion of construction waste which can be reused and identify the methods to reduce the waste generation without reducing the quality of the process. A 6-storey building construction site was selected for this research. The site was divided into six zones depending on the process. Ten waste materials were identified by considering the adverse effects on safety and health of people and the economic value of them. The generated construction waste in each zone was recorded per week for a period of five months. The data revealed that sand, cement, wood used for form work and rusted steel rods were the generated waste which has higher economic value in all zones. Structured interviews were conducted to gather information on how the materials are categorized as waste and the capability of reducing, reusing and recycling the waste. It was identified that waste is generated in following processes; ineffective storage of material for a longer time and improper handling of material during the work process. Further, the alteration of scheduled activities of construction work also yielded more waste. Finally, a proper management of construction waste is suggested to reduce and reuse waste.Keywords: construction-waste, effective management, reduce, reuse
Procedia PDF Downloads 202264 Biobased Facade: Illuminated Natural Fibre Polymer with Cardboard Core
Authors: Ralf Gliniorz, Carolin Petzoldt, Andreas Ehrlich, Sandra Gelbrich, Lothar Kroll
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The building envelope is integral part of buildings, and renewable resources have a key role in energy consumption. So our aim was the development and implementation of a free forming facade system, consisting of fibre-reinforced polymer, which is built up of commercial biobased resin systems and natural fibre reinforcement. The field of application is aimed in modern architecture, like the office block 'Fachagentur Nachwachsende Rohstoffe e.V.' with its oak wood recyclate facade. The build-up of our elements is a classically sandwich-structured composite: face sheets as fibre-reinforced composite using polymer matrix, here a biobased epoxy, and natural fibres. The biobased core consists of stuck cardboard structure (BC-flute). Each element is manufactured from two shells in a counterpart, via hand lay-up laminate. These natural fibre skins and cardboard core have adhered 'wet-on-wet'. As a result, you get the effect of translucent face sheets with matrix illumination. Each created pixel can be controlled in RGB-colours and form together a screen at buildings. A 10 x 5 m² area 'NFP-BIO' with 25 elements is planned as a reference object in Chemnitz. The resolution is about 100 x 50 pixels. Specials are also the efficient technology of production and the possibility to extensively 3D-formed elements for buildings, replacing customary facade systems, which can give out information or advertising.Keywords: biobased facade, cardboard core, natural fibre skins, sandwich element
Procedia PDF Downloads 212263 Between Buddha and Tsar: Kalmyk Buddhist Sangha in Late Russian Empire
Authors: Elzyata Kuberlinova
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This study explores how the Kalmyk Buddhist sangha responded to the Russian empire’s administrative integration and how the Buddhist clerical institutions were shaped in the process of interaction with representatives of the predominantly Orthodox state. The eighteenth-nineteenth century Russian imperial regime adhered to a religion-centred framework to govern its diverse subjects. Within this framework, any form of religious authority was considered a useful tool in the imperial quest for legibility. As such, rather than imposing religious homogeneity, the Russian administration engineered a framework of religious toleration and integrated the non-Orthodox clerical institutions in the empire’s administration. In its attempt to govern the large body of Kalmyk Buddhist sangha, the Russian government had to incorporate the sangha into the imperial institutional establishment. To this end, the Russian government founded the Lamaist Spiritual Governing Board in 1834, which became a part of the civil administration, where the Kalmyk Buddhist affairs were managed under the supervision of the Russian secular authorities. In 1847 the Lamaist Spiritual Board was abolished and Buddhist religious authority was transferred to the Lama of the Kalmyk people. From 1847 until the end of the empire in 1917 the Lama was the manager and intermediary figure between the Russian authorities and the Kalmyks where religious affairs were concerned. Substantial evidence collected in archives in Elista, Astrakhan, Stavropol and St.Petersburg show that despite being on the government’s payroll, first the Lamaist Spiritual Governing Board and later on the Lama did not always serve the interests of the state, and did not always comply with the Russian authorities’ orders. Although being incorporated into the state administrative system the Lama often found ways to manoeuvre the web of the Russian imperial bureaucracy in order to achieve his own goals. The Lama often used ‘every-day forms of resistance’ such as feigned misinterpretation, evasion, false compliance, feigned ignorance, and sabotage in order to resist without directly confronting or challenging the state orders.Keywords: Buddhist Sangha, intermediary, Kalmyks, Lama, legibility, resistance, reform, Russian empire
Procedia PDF Downloads 222262 Analysis of a Lignocellulose Degrading Microbial Consortium to Enhance the Anaerobic Digestion of Rice Straws
Authors: Supanun Kangrang, Kraipat Cheenkachorn, Kittiphong Rattanaporn, Malinee Sriariyanun
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Rice straw is lignocellulosic biomass which can be utilized as substrate for the biogas production. However, due to the property and composition of rice straw, it is difficult to be degraded by hydrolysis enzymes. One of the pretreatment method that modifies such properties of lignocellulosic biomass is the application of lignocellulose-degrading microbial consortia. The aim of this study is to investigate the effect of microbial consortia to enhance biogas production. To select the high efficient consortium, cellulase enzymes were extracted and their activities were analyzed. The results suggested that microbial consortium culture obtained from cattle manure is the best candidate compared to decomposed wood and horse manure. A microbial consortium isolated from cattle manure was then mixed with anaerobic sludge and used as inoculum for biogas production. The optimal conditions for biogas production were investigated using response surface methodology (RSM). The tested parameters were the ratio of amount of microbial consortium isolated and amount of anaerobic sludge (MI:AS), substrate to inoculum ratio (S:I) and temperature. Here, the value of the regression coefficient R2 = 0.7661 could be explained by the model which is high to advocate the significance of the model. The highest cumulative biogas yield was 104.6 ml/g-rice straw at optimum ratio of MI:AS, ratio of S:I, and temperature of 2.5:1, 15:1 and 44°C respectively.Keywords: lignocellulolytic biomass, microbial consortium, cellulase, biogas, Response Surface Methodology (RSM)
Procedia PDF Downloads 398261 Advancing Environmental Remediation Through the Production of Functional Porous Materials from Phosphorite Residue Tailings
Authors: Ali Mohammed Yimer, Ayalew Assen, Youssef Belmabkhout
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Environmental remediation is a pressing global concern, necessitating innovative strategies to address the challenges posed by industrial waste and pollution. This study aims to advance environmental remediation by developing cutting-edge functional porous materials from phosphorite residue tailings. Phosphorite mining activities generate vast amounts of waste, which pose significant environmental risks due to their contaminants. The proposed approach involved transforming these phosphorite residue tailings into valuable porous materials through a series of physico-chemical processes including milling, acid-base leaching, designing or templating as well as formation processes. The key components of the tailings were extracted and processed to produce porous arrays with high surface area and porosity. These materials were engineered to possess specific properties suitable for environmental remediation applications, such as enhanced adsorption capacity and selectivity for target contaminants. The synthesized porous materials were thoroughly characterized using advanced analytical techniques (XRD, SEM-EDX, N2 sorption, TGA, FTIR) to assess their structural, morphological, and chemical properties. The performance of the materials in removing various pollutants, including heavy metals and organic compounds, were evaluated through batch adsorption experiments. Additionally, the potential for material regeneration and reusability was investigated to enhance the sustainability of the proposed remediation approach. The outdoors of this research holds significant promise for addressing the environmental challenges associated with phosphorite residue tailings. By valorizing these waste materials into porous materials with exceptional remediation capabilities, this study contributes to the development of sustainable and cost-effective solutions for environmental cleanup. Furthermore, the utilization of phosphorite residue tailings in this manner offers a potential avenue for the remediation of other contaminated sites, thereby fostering a circular economy approach to waste management.Keywords: functional porous materials, phosphorite residue tailings, adsorption, environmental remediation, sustainable solutions
Procedia PDF Downloads 59260 Evaluation of Energy Efficiency Development Perspectives in Lithuanian Furniture Industry
Authors: J. Vasauskaite
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From the perspective of Lithuanian furniture enterprises, the role of energy efficiency is significant as it leads to direct economic benefits, increased competitiveness and higher productivity. There are various possible improvements in energy efficiency in industry: changes in the production process, investment in R&D, implementation of energy-saving technologies or energy management systems. The research aims to contribute the understanding of energy efficiency importance in industry by presenting possible improvements of energy use in different manufacturing process of enterprises. The evaluation methodology included quantitative and qualitative research methods: the comparative and statistical analysis of primary and secondary sources of information. This paper provides the detailed analysis of the energy efficiency development opportunities and challenges in Lithuanian furniture industry. The results of the study show the importance of technological innovations, energy efficiency policies and environmental management strategies in developing energy efficiency within the wood and furniture industry. The analysis of energy efficiency development in Lithuanian furniture industry showed that the industrial activities are influenced by various internal and external factors such as increasing flows of products, human resources and overall management decisions; dynamic growth and increasing competition; emerging need for environmental information. In the light of these factors, Lithuanian furniture industry has undergone significant changes – restructuring, technological advances and business model innovations, allowing it to be more export-oriented and focus on upgrading quality, design and innovation.Keywords: energy efficiency, energy policy, furniture industry, technological innovation
Procedia PDF Downloads 510259 Synthesis, Characterization and Photocatalytic Activity of Electrospun Zinc and/or Titanium Oxide Nanofibers for Methylene Blue Degradation
Authors: Zainab Dahrouch, Beatrix Petrovičová, Claudia Triolo, Fabiola Pantò, Angela Malara, Salvatore Patanè, Maria Allegrini, Saveria Santangelo
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Synthetic dyes dispersed in water cause environmental damage and have harmful effects on human health. Methylene blue (MB) is broadly used as a dye in the textile, pharmaceutical, printing, cosmetics, leather, and food industries. The complete removal of MB is difficult due to the presence of aromatic rings in its structure. The present study is focused on electrospun nanofibers (NFs) with engineered architecture and surface to be used as catalysts for the photodegradation of MB. Ti and/or Zn oxide NFs are produced by electrospinning precursor solutions with different Ti: Zn molar ratios (from 0:1 to 1:0). Subsequent calcination and cooling steps are operated at fast rates to generate porous NFs with capture centers to reduce the recombination rate of the photogenerated charges. The comparative evaluation of the NFs as photocatalysts for the removal of MB from an aqueous solution with a dye concentration of 15 µM under UV irradiation shows that the binary (wurtzite ZnO and anatase TiO₂) oxides exhibit higher catalytic activity compared to ternary (ZnTiO₃ and Zn₂TiO₄) oxides. The higher band gap and lower crystallinity of the ternary oxides are responsible for their lower photocatalytic activity. It has been found that the optimal load for the wurtzite ZnO is 0.66 mg mL⁻¹, obtaining a degradation rate of 7.94.10⁻² min⁻¹. The optimal load for anatase TiO₂ is lower (0.33 mg mL⁻¹) and the corresponding rate constant (1.12×10⁻¹ min⁻¹) is higher. This finding (higher activity with lower load) is of crucial importance for the scaling up of the process on an industrial scale. Indeed, the anatase NFs outperform even the commonly used P25-TiO₂ benchmark. Besides, they can be reused twice without any regeneration treatment, with 5.2% and 18.7% activity decrease after second and third use, respectively. Thanks to the scalability of the electrospinning technique, this laboratory-scale study provides a perspective towards the sustainable large-scale manufacture of photocatalysts for the treatment of industry effluents.Keywords: anatase, capture centers, methylene blue dye, nanofibers, photodegradation, zinc oxide
Procedia PDF Downloads 157258 Feasibility Study on the Bioattactants from Pandanus Palm Extracts for Trapping Rice Insect Pests
Authors: Pisit Poolprasert, Phakin Kubchanan, Keerati Tanruean, Wisanu Thongchai, Yuttasak Chammui, Wirot Likittrakulwong
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Rice insect pests are problems to rice production. Use of chemicals to minimize these problems of insect pests in paddy field can lead to the residue and affect the health of farmers. Therefore, botanical extracts applied for controlling rice serious enemies should be promoted especially use of plant extract as attractants to lure insects. This research aimed to feasibility study of bioattractants from pandanus palm extracts for trapping insect pets using two different trap models, including plastic bottle and yellow sticky traps. Two main growth and development stages of rice, namely tillering and booting stages, were selected and trapped. The results from both trap models revealed that four rice insect species, including Orseolia oryzae (Wood-Mason), Nilaparvata lugens, Recilia dorsalis, and Nephotettix nigropictus from three families (Cecidomyiidae, Cicadellidae and Delphacidae) and two main orders (Diptera and Hemiptera) were exhibited. All rice insect species mentioned could be found from the yellow sticky trap that were higher than in the bottle trap in which only O. oryzae could be only trapped. From this survey, it was indicated that the yellow sticky trap coated with pandanus palm extracts had a promising potential to use as an attractant for the detection of rice paddy insects in the next future.Keywords: pandanus palm, bioattractant, bottle trap, yellow sticky trap
Procedia PDF Downloads 125257 Sustainability of Vernacular Architecture in Zegalli Houses in Northern Iran with Emphasis on Their Seismic Behavior
Authors: Mona Zaryoun, Mahmood Hosseini, Seyed Mohammad Hassan Khalkhali, Haniyeh Okhovat
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Zegalli houses in Guilan province, northern Iran, are a type of vernacular houses which their foundation, skeleton and walls all have been made of wood. The only houses which could survive the major Manjil-Rudbar earthquake of 1990 with a magnitude of 7.2 were these houses. Regarding this fact, some researchers started thinking of this type of foundations used in these houses to benefit from rocking-wise behavior. On the one hand, the relatively light weight of the houses, have helped these houses to withstand well against seismic excitations. In this paper at first a brief description of Zegalli houses and their architectural features, with emphasis on their foundation is presented. in the next stage foundation of one of these houses is modeled as a sample by a using a computer program, which has been developed in MATLAB environment, and by using the horizontal and vertical accelerograms of a set of selected site compatible earthquakes, a series of time history analysis (THA) are carried out to investigate the behavior of this type of houses against earthquake. Based on numerical results of THA it can be said that even without no sliding at the foundation timbers, only due to the rocking which occurs in various levels of the foundation the seismic response of the house is significantly reduced., which results in their stability subjected to earthquakes with peak ground acceleration of around 0.35g. Therefore, it can be recommended the Zegalli houses are considered as sustainable Iranian vernacular architecture, and it can be recommended that the use of these houses and their architecture and their structural merits are reconsidered by architects as well as civil and structural engineers.Keywords: MATLAB software, rocking behavior, time history analysis, Zegalli houses
Procedia PDF Downloads 288256 Assessing the Sheltering Response in the Middle East: Studying Syrian Camps in Jordan
Authors: Lara A. Alshawawreh, R. Sean Smith, John B. Wood
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This study focuses on the sheltering response in the Middle East, specifically through reviewing two Syrian refugee camps in Jordan, involving Zaatari and Azraq. Zaatari camp involved the rapid deployment of tents and shelters over a very short period of time and Azraq was purpose built and pre-planned over a longer period. At present, both camps collectively host more than 133,000 occupants. Field visits were taken to both camps and the main issues and problems in the sheltering response were highlighted through focus group discussions with camp occupants and inspection of shelter habitats. This provided both subjective and objective research data sources. While every case has its own significance and deployment to meet humanitarian needs, there are some common requirements irrespective of geographical region. The results suggest that there is a gap in the suitability of the required habitat needs and what has been provided. It is recommended that the global international response and support could be improved in relation to the habitat form, construction type, layout, function and critically the cultural aspects. Services, health and hygiene are key elements to the shelter habitat provision. The study also identified the amendments to shelters undertaken by the beneficiaries providing insight into their key main requirements. The outcomes from this study could provide an important learning opportunity to develop improved habitat response for future shelters.Keywords: culture, post-disaster, refugees, shelters
Procedia PDF Downloads 488255 Characteristics of Old-Growth and Secondary Forests in Relation to Age and Typhoon Disturbance
Authors: Teng-Chiu Lin, Pei-Jen Lee Shaner, Shin-Yu Lin
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Both forest age and physical damages due to weather events such as tropical cyclones can influence forest characteristics and subsequently its capacity to sequester carbon. Detangling these influences is therefore a pressing issue under climate change. In this study, we compared the compositional and structural characteristics of three forests in Taiwan differing in age and severity of typhoon disturbances. We found that the two forests (one old-growth forest and one secondary forest) experiencing more severe typhoon disturbances had shorter stature, higher wood density, higher tree species diversity, and lower typhoon-induced tree mortality than the other secondary forest experiencing less severe typhoon disturbances. On the other hand, the old-growth forest had a larger amount of woody debris than the two secondary forests, suggesting a dominant role of forest age on woody debris accumulation. Of the three forests, only the two experiencing more severe typhoon disturbances formed new gaps following two 2015 typhoons, and between these two forests, the secondary forest gained more gaps than the old-growth forest. Consider that older forests generally have more gaps due to a higher background tree mortality, our findings suggest that the age effects on gap dynamics may be reversed by typhoon disturbances. This study demonstrated the effects of typhoons on forest characteristics, some of which could negate the age effects and rejuvenate older forests. If cyclone disturbances were to intensity under climate change, the capacity of older forests to sequester carbon may be reduced.Keywords: typhoon, canpy gap, coarse woody debris, forest stature, forest age
Procedia PDF Downloads 270254 Landfill Failure Mobility Analysis: A Probabilistic Approach
Authors: Ali Jahanfar, Brajesh Dubey, Bahram Gharabaghi, Saber Bayat Movahed
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Ever increasing population growth of major urban centers and environmental challenges in siting new landfills have resulted in a growing trend in design of mega-landfills some with extraordinary heights and dangerously steep slopes. Landfill failure mobility risk analysis is one of the most uncertain types of dynamic rheology models due to very large inherent variabilities in the heterogeneous solid waste material shear strength properties. The waste flow of three historic dumpsite and two landfill failures were back-analyzed using run-out modeling with DAN-W model. The travel distances of the waste flow during landfill failures were calculated approach by taking into account variability in material shear strength properties. The probability distribution function for shear strength properties of the waste material were grouped into four major classed based on waste material compaction (landfills versus dumpsites) and composition (high versus low quantity) of high shear strength waste materials such as wood, metal, plastic, paper and cardboard in the waste. This paper presents a probabilistic method for estimation of the spatial extent of waste avalanches, after a potential landfill failure, to create maps of vulnerability scores to inform property owners and residents of the level of the risk.Keywords: landfill failure, waste flow, Voellmy rheology, friction coefficient, waste compaction and type
Procedia PDF Downloads 291253 Modification of Date Palm Leaflets Fibers Used as Thermoplastic Reinforcement
Authors: K. Almi, S.Lakel, A. Benchabane, A. Kriker
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The fiber–matrix compatibility can be improved if suitable enforcements are chosen. Whenever the reinforcements have more thermal stability, they can resist to the main processes for wood–thermoplastic composites. This paper is an investigation of effect of different treatment process on the mechanical proprieties and on the thermal stability of date palm leaflets fibers with a view to improve the date palm fiber proprieties used as reinforcement of thermoplastic materials which main processes require extrusion, hot press. To compare the effect of alkali and acid treatment on the date palm leaflets fiber properties, different treatment were used such as Sodium hydroxide NaOH solution, aluminium chloride AlCl3 and acid treatment with HCL solution. All treatments were performed at 70°C for 4h and 48 h. The mechanical performance (tensile strength and elongation) is affected by immersion time in alkaline and acid solutions. The reduction of the tensile strength and elongation of fibers at 48h was higher in acid treatment than in alkali treatment at high concentration. No significant differences were observed in mechanical and thermal proprieties of raw fibers and fibers submerged in AlCl3 at low concentration 1% for 48h. Fibers treated by NaOH at 6% for 4h showed significant increase in the mechanical proprieties and thermal stability of date palm leaflets fibers. Hence, soda treatment is necessary to improve the fibers proprieties and consequently optimize the composite performance.Keywords: date palm fibers, surface treatments, thermoplastic composites, thermal analysis
Procedia PDF Downloads 342252 Biological Hazards and Laboratory inflicted Infections in Sub-Saharan Africa
Authors: Godfrey Muiya Mukala
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This research looks at an array of fields in Sub-Saharan Africa comprising agriculture, food enterprises, medicine, organisms genetically modified, microbiology, and nanotechnology that can be gained from biotechnological research and development. Findings into dangerous organisms, mainly bacterial germs, rickettsia, fungi, parasites, or organisms that are genetically engineered, have immensely posed questions attributed to the biological danger they bring forth to human beings and the environment because of their uncertainties. In addition, the recurrence of previously managed diseases or the inception of new diseases are connected to biosafety challenges, especially in rural set-ups in low and middle-income countries. Notably, biotechnology laboratories are required to adopt biosafety measures to protect their workforce, community, environment, and ecosystem from unforeseen materials and organisms. Sensitization and inclusion of educational frameworks for laboratory workers are essential to acquiring a solid knowledge of harmful biological agents. This is in addition to human pathogenicity, susceptibility, and epidemiology to the biological data used in research and development. This article reviews and analyzes research intending to identify the proper implementation of universally accepted practices in laboratory safety and biological hazards. This research identifies ideal microbiological methods, adequate containment equipment, sufficient resources, safety barriers, specific training, and education of the laboratory workforce to decrease and contain biological hazards. Subsequently, knowledge of standardized microbiological techniques and processes, in addition to the employment of containment facilities, protective barriers, and equipment, is far-reaching in preventing occupational infections. Similarly, reduction of risks and prevention may be attained by training, education, and research on biohazards, pathogenicity, and epidemiology of the relevant microorganisms. In this technique, medical professionals in rural setups may adopt the knowledge acquired from the past to project possible concerns in the future.Keywords: sub-saharan africa, biotechnology, laboratory, infections, health
Procedia PDF Downloads 77251 Synthesis and Two-Photon Polymerization of a Cytocompatibility Tyramine Functionalized Hyaluronic Acid Hydrogel That Mimics the Chemical, Mechanical, and Structural Characteristics of Spinal Cord Tissue
Authors: James Britton, Vijaya Krishna, Manus Biggs, Abhay Pandit
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Regeneration of the spinal cord after injury remains a great challenge due to the complexity of this organ. Inflammation and gliosis at the injury site hinder the outgrowth of axons and hence prevent synaptic reconnection and reinnervation. Hyaluronic acid (HA) is the main component of the spinal cord extracellular matrix and plays a vital role in cell proliferation and axonal guidance. In this study, we have synthesized and characterized a photo-cross-linkable HA-tyramine (tyr) hydrogel from a chemical, mechanical, electrical, biological and structural perspective. From our experimentation, we have found that HA-tyr can be synthesized with controllable degrees of tyramine substitution using click chemistry. The complex modulus (G*) of HA-tyr can be tuned to mimic the mechanical properties of the native spinal cord via optimization of the photo-initiator concentration and UV exposure. We have examined the degree of tyramine-tyramine covalent bonding (polymerization) as a function of UV exposure and photo-initiator use via Photo and Nuclear magnetic resonance spectroscopy. Both swelling and enzymatic degradation assays were conducted to examine the resilience of our 3D printed hydrogel constructs in-vitro. Using a femtosecond 780nm laser, the two-photon polymerization of HA-tyr hydrogel in the presence of riboflavin photoinitiator was optimized. A laser power of 50mW and scan speed of 30,000 μm/s produced high-resolution spatial patterning within the hydrogel with sustained mechanical integrity. Using dorsal root ganglion explants, the cytocompatibility of photo-crosslinked HA-tyr was assessed. Using potentiometry, the electrical conductivity of photo-crosslinked HA-tyr was assessed and compared to that of native spinal cord tissue as a function of frequency. In conclusion, we have developed a biocompatible hydrogel that can be used for photolithographic 3D printing to fabricate tissue engineered constructs for neural tissue regeneration applications.Keywords: 3D printing, hyaluronic acid, photolithography, spinal cord injury
Procedia PDF Downloads 152250 Sexual Health And Male Fertility: Improving Sperm Health With Focus On Technology
Authors: Diana Peninger
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Over 10% of couples in the U.S. have infertility problems, with roughly 40% traceable to the male partner. Yet, little attention has been given to improving men’s contribution to the conception process. One solution that is showing promise in increasing conception rates for IVF and other assisted reproductive technology treatments is a first-of-its-kind semen collection that has been engineered to mitigate sperm damage caused by traditional collection methods. Patients are able to collect semen at home and deliver to clinics within 48 hours for use in fertility analysis and treatment, with less stress and improved specimen viability. This abstract will share these findings along with expert insight and tips to help attendees understand the key role sperm collection plays in addressing and treating reproductive issues, while helping to improve patient outcomes and success. Our research was to determine if male reproductive outcomes can be increased by improving sperm specimen health with a focus on technology. We utilized a redesigned semen collection cup (patented as the Device for Improved Semen Collection/DISC—U.S. Patent 6864046 – known commercially as a ProteX) that met a series of physiological parameters. Previous research demonstrated significant improvement in semen perimeters (motility forward, progression, viability, and longevity) and overall sperm biochemistry when the DISC is used for collection. Animal studies have also shown dramatic increases in pregnancy rates. Our current study compares samples collected in the DISC, next-generation DISC (DISCng), and a standard specimen cup (SSC), dry, with the 1 mL measured amount of media and media in excess ( 5mL). Both human and animal testing will be included. With sperm counts declining at alarming rates due to environmental, lifestyle, and other health factors, accurate evaluations of sperm health are critical to understanding reproductive health, origins, and treatments of infertility. An increase in the health of the sperm as measured by extensive semen parameter analysis and improved semen parameters stable for 48 hours, expanding the processing time from 1 hour to 48 hours were also demonstrated.Keywords: reprodutive, sperm, male, infertility
Procedia PDF Downloads 129249 Mitigating Nitrous Oxide Production from Nitritation/Denitritation: Treatment of Centrate from Pig Manure Co-Digestion as a Model
Authors: Lai Peng, Cristina Pintucci, Dries Seuntjens, José Carvajal-Arroyo, Siegfried Vlaeminck
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Economic incentives drive the implementation of short-cut nitrogen removal processes such as nitritation/denitritation (Nit/DNit) to manage nitrogen in waste streams devoid of biodegradable organic carbon. However, as any biological nitrogen removal process, the potent greenhouse gas nitrous oxide (N2O) could be emitted from Nit/DNit. Challenges remain in understanding the fundamental mechanisms and development of engineered mitigation strategies for N2O production. To provide answers, this work focuses on manure as a model, the biggest wasted nitrogen mass flow through our economies. A sequencing batch reactor (SBR; 4.5 L) was used treating the centrate (centrifuge supernatant; 2.0 ± 0.11 g N/L of ammonium) from an anaerobic digester processing mainly pig manure, supplemented with a co-substrate. Glycerin was used as external carbon source, a by-product of vegetable oil. Out-selection of nitrite oxidizing bacteria (NOB) was targeted using a combination of low dissolved oxygen (DO) levels (down to 0.5 mg O2/L), high temperature (35ºC) and relatively high free ammonia (FA) (initially 10 mg NH3-N/L). After reaching steady state, the process was able to remove 100% of ammonium with minimum nitrite and nitrate in the effluent, at a reasonably high nitrogen loading rate (0.4 g N/L/d). Substantial N2O emissions (over 15% of the nitrogen loading) were observed at the baseline operational condition, which were even increased under nitrite accumulation and a low organic carbon to nitrogen ratio. Yet, higher DO (~2.2 mg O2/L) lowered aerobic N2O emissions and weakened the dependency of N2O on nitrite concentration, suggesting a shift of N2O production pathway at elevated DO levels. Limiting the greenhouse gas emissions (environmental protection) from such a system could be substantially minimized by increasing the external carbon dosage (a cost factor), but also through the implementation of an intermittent aeration and feeding strategy. Promising steps forward have been presented in this abstract, yet at the conference the insights of ongoing experiments will also be shared.Keywords: mitigation, nitrous oxide, nitritation/denitritation, pig manure
Procedia PDF Downloads 249248 The Material Behavior in Curved Glulam Beam of Jabon Timber
Authors: Erma Desmaliana, Saptahari Sugiri
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Limited availability of solid timber in large dimensions becomes a problem. The demands of timbers in Indonesia is more increasing compared to its supply from natural forest. It is associated with the issues of global warming and environmental preservation. The uses of timbers from HTI (Industrial Planting Forest) and HTR (Society Planting Forest), such as Jabon, is an alternative source that required to solve these problems. Having shorter lifespan is the benefit of HTI/HTR timbers, although they are relatively smaller in dimension and lower in strength. Engineering Wood Product (EWP) such as glulam (glue-laminated) timber, is required to overcome their losses. Glulam is fabricated by gluing the wooden planks that having a thickness of 20 to 45 mm with an adhesive material and a certain pressure. Glulam can be made a curved beam, is one of the advantages, thus making it strength is greater than a straight beam. This paper is aimed to know the material behavior of curved glue-laminated beam of Jabon timber. Preliminary methods was to gain physical and mechanical properties, and glue spread strength of Jabon timber, which following the ASTM D-143 standard test method. Dimension of beams were 50 mm wide, 760 mm span, 50 mm thick, and 50 mm rise. Each layer of Jabon has a thickness of 5 mm and is glued with polyurethane. Cold press will be applied to beam laminated specimens for more than 5 hours. The curved glue-laminated beams specimens will be tested about the bending behavior. This experiments aims to obtain the increasing of load carrying capacity and stiffness of curved glulam beam.Keywords: curved glulam beam, HTR&HTI, load carrying, strength
Procedia PDF Downloads 298247 Modelling the Impacts of Geophysical Parameters on Deforestation and Forest Degradation in Pre and Post Ban Logging Periods in Hindu Kush Himalayas
Authors: Alam Zeb, Glen W. Armstrong, Muhammad Qasim
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Loss of forest cover is one of the most important land cover changes and has been of great concern to policy makers. This study quantified forest cover changes over pre logging ban (1973-1993) and post logging ban (1993-2015) to examine the role of geophysical factors and spatial attributes of land in the two periods. We show that despite a complete ban on green felling, forest cover decreased by 28% and mostly converted to rangeland. Nevertheless, the logging ban was completely effective in controlling agriculture expansion. The binary logistic regression revealed that the south facing aspects at low elevation witnessed more deforestation in the pre-ban period compared to post-ban. Opposite to deforestation, forest degradation was more prominent on the northern aspects at higher elevation during the policy period. Agriculture expansion was widespread in the low elevation flat areas with gentle slope, while during the policy period agriculture contraction in the form of regeneration was observed on the low elevation areas of north facing slopes. All proximity variables, except distance to administrative boundary, showed a similar trend across the two periods and were important explanatory variables in understanding forest and agriculture expansion. The changes in determinants of forest and agriculture expansion and contraction over the two periods might be attributed to the influence of policy and a general decrease in resource availability.Keywords: forest conservation , wood harvesting ban, logistic regression, deforestation, forest degradation, agriculture expansion, Chitral, Pakistan
Procedia PDF Downloads 230246 Need for Shariah Screening of Companies in Nigeria: Lessons from Other Jurisdictions
Authors: Aishat Abdul-Qadir Zubair
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Background: The absence of Shari’ah screening methodology for companies in Nigeria has further engineered the uncertainty surrounding the acceptability of investing in certain companies by people professing the religion of Islam due to the nature of the activities carried out by these companies. There are some existing shariah screening indices in other jurisdictions whose criteria can be used to check if a company or business is shariah-compliant or not. Examples such as FTSE, DJIM, Standard and Poor to mention just a few. What these indices have tried to do is to ensure that there are benchmarks to check with before investing in companies that carry out mixed activities in their business, wherein some are halal and others may be haram. Purpose: There have been numerous studies on the need to adopt certain screening methodologies as well as call for new methods in screening companies for shariah compliance in order to suit the investments needs of Muslims in other jurisdictions. It is, however, unclear how suitable these methodologies will be to Nigeria. This paper, therefore, seeks to address this gap to consider an appropriate screening methodology to be employed in Nigeria, drawing from the experience of other jurisdictions. Methods: This study employs a triangulation of both quantitative and qualitative methods to analyze the need for Shari’ah screening of companies in Nigeria. The qualitative method is used by way of ijtihad, and this study tries to apply some Islamic Principles of Maqasid al-shari’ah as well as Qawaid al-Fiqiyyah to analyze activities of companies in order to ensure that they are indeed Shari’ah compliant. In addition, using the quantitative data gathered from the interview survey, the perspective of the investors with regards to the need for Shari’ah screening of companies in Nigeria is further analyzed. Results: The result of the study shows that there is a lack of awareness from the teeming Muslim population in Nigeria on the need for Shari’ah screening of companies in Nigeria. The result further shows that there is the need to take into cognizance the peculiar nature of company activities in Nigeria before any particular Shari’ah screening methodology is adopted and setting the necessary benchmarks. Conclusion and Implications: The study concludes that there is the need to ensure that the conscious Muslims in Nigeria screen companies for Shari’ah compliance so that they can easily identify the companies to invest in. The paper, therefore, recommends that the Nigerian government need to come up with a screening methodology that will suit the peculiar nature of companies in Nigeria. The study thus has a direct implication on the Investment regulatory bodies in Nigeria such as the Securities and Exchange Commission (SEC), Central Bank of Nigeria (CBN) as well as the investor Muslims.Keywords: Shari'ah screening, Muslims, investors, companies
Procedia PDF Downloads 167245 The Implementation of Entrepreneurial Marketing in Small Business Enterprise
Authors: Iin Mayasari
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This study aims at exploring the influence of aspects of entrepreneurial marketing on a firm’s performance. Entrepreneurs are not only supported by resources control to obtain sustainable competitive advantage, but it should also be supported by intangible resources. Entrepreneurial marketing provides the opportunity for entrepreneurs to proactively find better ways to create value for desired customers, to create innovation, and to build customer equity. Entrepreneurial marketing has the medium between entrepreneurship and marketing, and serves as an umbrella for many of the emergent perspectives on marketing. It has eight underlying dimensions. They are proactiveness, calculated risk-taking, innovativeness, an opportunity focus, entrepreneurial orientation, resource leveraging, customer intensity, and value creating. The research method of the study was a qualitative study by having an interview with 8 small companies in Kudus Region, the Central Java, Indonesia. The interviewees were the owner and the manager of the company that had the scope work of small business enterprise in wood crafting industry. The interview was related to the implementation of the elements of the entrepreneurial marketing. The result showed that the small business enterprises had implemented the elements of entrepreneurial marketing in supporting their daily activities. The understanding based on the theoretical implementation was well executed by the owner and managers. The problems in managing small business enterprises were related to the full support by the government and the branding management. Furthermore, the innovation process should be improved especially the use of internet to promote the product, to expand the market and to increase the firm’s performance.Keywords: entrepreneurial marketing, innovativeness, risk taking, opportunity focus
Procedia PDF Downloads 298244 Intensified Electrochemical H₂O₂ Synthesis and Highly Efficient Pollutant Removal Enabled by Nickel Oxides with Surface Engineered Facets and Vacancies
Authors: Wenjun Zhang, Thao Thi Le, Dongyup Shin, Jong Min Kim
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Electrochemical hydrogen peroxide (H₂O₂) synthesis holds significant promise for decentralized environmental remediation through the electro-Fenton process. However, challenges persist, such as the absence of robust electrocatalysts for the selective two-electron oxygen reduction reaction (2e⁻ ORR) and the high cost and sluggish kinetics of conventional electro-Fenton systems in treating highly concentrated wastewater. This study introduces an efficient water treatment system for removing substantial quantities of organic pollutants using an advanced electro-Fenton system coupled with a high-valent NiO catalyst. By employing a precipitation method involving crystal facet and cation vacancy engineering, a trivalent Ni (Ni³⁺)-rich NiO catalyst with a (111)-domain-exposed crystal facet, named {111}-NivO, was synthesized. This catalyst exhibited a remarkable 96% selectivity and a high mass activity of 59 A g⁻¹ for H₂O₂ production, outperforming all previously reported Ni-based catalysts. Furthermore, an advanced electro-Fenton system, integrated with a flow cell for electrochemical H₂O₂ production, was utilized to achieve 100% removal of 50 ppm bisphenol A (BPA) in 200 mL of wastewater under heavy-duty conditions, reaching a superior rapid degradation rate (4 min, k = 1.125 min⁻¹), approximately 102 times faster than the conventional electro-Fenton system. The hyper-efficiency is attributed to the continuous and appropriate supply of H₂O₂, the provision of O₂, and the timely recycling of the electrolyte under high current density operation. This catalyst also demonstrated a 93% removal of total organic carbon after 2 hours of operation and can be applied for efficient removal of highly concentrated phenol pollutants from aqueous systems, which opens new avenues for wastewater treatment.Keywords: hydrogen peroxide production, nickel oxides, crystal facet and cation vacancy engineering, wastewater treatment, flow cell, electro-Fenton
Procedia PDF Downloads 59243 An Integrated Approach to Solid Waste Management of Karachi, Pakistan (Waste-to-Energy Options)
Authors: Engineer Dilnawaz Shah
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Solid Waste Management (SWM) is perhaps one of the most important elements constituting the environmental health and sanitation of the urban developing sector. The management system has several components that are integrated as well as interdependent; thus, the efficiency and effectiveness of the entire system are affected when any of its functional components fails or does not perform up to the level mark of operation. Sindh Solid Waste Management Board (SSWMB) is responsible for the management of solid waste in the entire city. There is a need to adopt the engineered approach in the redesigning of the existing system. In most towns, street sweeping operations have been mechanized and done by machinery operated by vehicles. Construction of Garbage Transfer Stations (GTS) at a number of locations within the city will cut the cost of transportation of waste to disposal sites. Material processing, recovery of recyclables, compaction, volume reduction, and increase in density will enable transportation of waste to disposal sites/landfills via long vehicles (bulk transport), minimizing transport/traffic and environmental pollution-related issues. Development of disposal sites into proper sanitary landfill sites is mandatory. The transportation mechanism is through garbage vehicles using either hauled or fixed container systems employing crew for mechanical or manual loading. The number of garbage vehicles is inadequate, and due to comparatively long haulage to disposal sites, there are certain problems of frequent vehicular maintenance and high fuel costs. Foreign investors have shown interest in enterprising improvement schemes and proposed operating a solid waste management system in Karachi. The waste to Energy option is being considered to provide a practical answer to be adopted to generate power and reduce waste load – a two-pronged solution for the increasing environmental problem. The paper presents results and analysis of a recent study into waste generation and characterization probing into waste-to-energy options for Karachi City.Keywords: waste to energy option, integrated approach, solid waste management, physical and chemical composition of waste in Karachi
Procedia PDF Downloads 46242 Developing Customizable Scaffolds With Antimicrobial Properties for Vascular Tissue Regeneration Using Low Temperature Plasma
Authors: Komal Vig, Syamala Soumyakrishnan, Yadav Baral
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Bypass surgery, using the autologous vein has been one of the most effective treatments for cardiovascular diseases (CVD). More recently tissue engineering including engineered vascular grafts to synthesize blood vessels is gaining usage. Dacron and ePTFE has been employed for vascular grafts, however, these does not work well for small diameter grafts (<6 mm) due to intimal hyperplasia and thrombosis. In the present study PTFE was treated with LTP to improve the endothelialization of intimal surface of graft. Scaffolds were also modified with polyvinylpyrrolidone coated silver nanoparticles (Ag-PVP) and the antimicrobial peptides, p753 and p359. Human umbilical vein endothelial cells (HUVEC) were plated on the developed scaffolds and cell proliferation was determined by the MTT assay. Cells attachment on scaffolds was visualized by microscopy. mRNA expressions levels of different cell markers were investigated using quantitative real-time PCR (qPCR). X ray photoelectron spectroscopic confirmed the introduction of oxygenated functionalities from LTP air plasma. Microscopic and MTT assays indicated increase in cell viability in LTP treated scaffolds. Gene expression studies shows enhanced expression of cell adhesion marker Integrin- α 5 gene after LTP treatment. The KB test displayed a zone of inhibition for Ag-PVP, p753 and p359 of 19mm, 14mm, and 12mm respectively. To determine toxicity of antimicrobial agents to cells, MTT Assay was performed using HEK293 cells. MTT Assay exhibited that Ag-PVP and the peptides were non-toxic to cells at 100μg/mL and 50μg/mL, respectively. Live/dead analysis and plate count of treated bacteria exhibited bacterial inhibition on develop scaffold compared to non-treated scaffold. SEM was performed to analyze the structural changes of bacteria after treatment with antimicrobial agents. Gene expression studies were conducted on RNA from bacteria treated with Ag-PVP and peptides using qRT-PCR. Based on our initial results, more scaffolds alternatives will be developed and investigated for cell growth and vascularization studies.Keywords: low temperature plasma, vascular graft, HUVEC cells, antimicrobial
Procedia PDF Downloads 244241 Gadolinium-Based Polymer Nanostructures as Magnetic Resonance Imaging Contrast Agents
Authors: Franca De Sarno, Alfonso Maria Ponsiglione, Enza Torino
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Recent advances in diagnostic imaging technology have significantly contributed to a better understanding of specific changes associated with diseases progression. Among different imaging modalities, Magnetic Resonance Imaging (MRI) represents a noninvasive medical diagnostic technique, which shows low sensitivity and long acquisition time and it can discriminate between healthy and diseased tissues by providing 3D data. In order to improve the enhancement of MRI signals, some imaging exams require intravenous administration of contrast agents (CAs). Recently, emerging research reports a progressive deposition of these drugs, in particular, gadolinium-based contrast agents (GBCAs), in the body many years after multiple MRI scans. These discoveries confirm the need to have a biocompatible system able to boost a clinical relevant Gd-chelate. To this aim, several approaches based on engineered nanostructures have been proposed to overcome the common limitations of conventional CAs, such as the insufficient signal-to-noise ratios due to relaxivity and poor safety profile. In particular, nanocarriers, labeling or loading with CAs, capable of carrying high payloads of CAs have been developed. Currently, there’s no a comprehensive understanding of the thermodynamic contributions enable of boosting the efficacy of conventional CAs by using biopolymers matrix. Thus, considering the importance of MRI in diagnosing diseases, here it is reported a successful example of the next generation of these drugs where the commercial gadolinium chelate is incorporate into a biopolymer nanostructure, formed by cross-linked hyaluronic acid (HA), with improved relaxation properties. In addition, they are highlighted the basic principles ruling biopolymer-CA interactions in the perspective of their influence on the relaxometric properties of the CA by adopting a multidisciplinary experimental approach. On the basis of these discoveries, it is clear that the main point consists in increasing the rigidification of readily-available Gd-CAs within the biopolymer matrix by controlling the water dynamics, the physicochemical interactions, and the polymer conformations. In the end, the acquired knowledge about polymer-CA systems has been applied to develop of Gd-based HA nanoparticles with enhanced relaxometric properties.Keywords: biopolymers, MRI, nanoparticles, contrast agent
Procedia PDF Downloads 149