Search results for: gold concentration areas

Authors: Palingba Aimé Marie Doilkom, Mahamadou Koïta, Jean-michel Vouillamoz, Angelbert Biaou

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Most African populations rely on groundwater in rural areas for their consumption. Indeed, in the face of climate change and strong demographic growth, groundwater, particularly in the basement, is increasingly in demand. The question of the sustainability of water resources in this type of environment is therefore becoming a major issue. Groundwater recharge can be natural or artificial. Unlike natural recharge, which often results from the natural infiltration of surface water (e.g. a share of rainfall), artificial recharge consists of causing water infiltration through appropriate developments to artificially replenish the water stock of an aquifer. Artificial recharge is, therefore, one of the measures that can be implemented to secure water supply, combat the effects of climate change, and, more generally, contribute to improving the quantitative status of groundwater bodies. It is in this context that the present research is conducted with the aim of developing artificial recharge in order to contribute to the sustainability of basement aquifers in a context of climatic variability and constantly increasing water needs of populations. In order to achieve the expected results, it is therefore important to determine the characteristics of the infiltration basins and to identify the areas suitable for their implementation. The geometry of the aquifer was reproduced, and the hydraulic properties of the aquifer were collected and characterized, including boundary conditions, hydraulic conductivity, effective porosity, recharge, Van Genuchten parameters, and saturation indices. The aquifer of the Sanon experimental site is made up of three layers, namely the saprolite, the fissured horizon, and the healthy basement. Indeed, the saprolite and the fissured medium were considered for the simulations. The first results with FEFLOW model show that the water table reacts continuously for the first 100 days before stabilizing. The hydraulic charge increases by an average of 1 m. The further away from the basin, the less the water table reacts. However, if a variable hydraulic head is imposed on the basins, it can be seen that the response of the water table is not uniform over time. The lower the basin hydraulic head, the less it affects the water table. These simulations must be continued by improving the characteristics of the basins in order to obtain the appropriate characteristics for a good recharge.

Keywords: basement area, FEFLOW, infiltration basin, MAR

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Authors: Ferdi Sönmez, Başak Buluz

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Agility in Knowledge Management (AKM) tries to capture agility requirements and their respective answers within the framework of knowledge and learning for organizations. Since it is rather a new construct, it is difficult to claim that it has been sufficiently discussed and analyzed in practical and theoretical realms. Like the term ‘agile learning’, it is also commonly addressed in the software development and information technology fields and across the related areas where those technologies can be applied. The organizational perspective towards AKM, seems to need some more time to become scholarly mature. Nevertheless, in the literature one can come across some implicit usages of this term occasionally. This research is aimed to explore the conceptual background of agility in KM, re-conceptualize it and extend it to business applications with a special focus on e-business.

Keywords: knowledge management, agility requirements, agility, knowledge

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Authors: Aimeurnadjette, Hammoudi Abd Erahmen, Bordjibaouahiba

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For many years, the pesticides used in agriculture have been responsible for environmental degradation, particularly noticeable in the areas of intensive agriculture, particularly through contamination of surface and groundwater. Our study was conducted to isolate and identify the microflora of water polluted by pesticides in an area with an agricultural vocation (Ben M'Hidi) subject to the pesticide effect for several years. Isolated fungal strains were identified based on the morphology of their vegetative and reproductive apparatus. The micromycètes were obtained; they belong mainly to the genera Aspergillus, Penicillium and Trichoderma. Furthermore, most bacterial strains characterized in this work, are that of the genus Aeromonas, Pseudomonas that are widely represented in the study of the biodegradation of pesticides.

Keywords: isolated, strains, polluted, pesticides

Procedia PDF Downloads 79

Authors: Mohamed Redha Menani

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The Northern Saharan aquifer system “SASS” shared by Algeria, Libya, and Tunisia, covers a surface of about 1 100 000 km². It is composed of superposed aquifers; the upper one is the “Continental terminal – CT” (Eocene calcareous formation) situated at 400 m depth in average, while the” Continental Intercalaire – CI”(clay sands from Albian to Lower Cretaceous) is generally at 1500 m depth. This aquifer system is situated in a dry zone with a very weak current recharge but with a non-renewable big volume stored, estimated between 20 000 and 31 000 km³. From 1970 to nowadays, the exploitation of the SASS has increased from 0.6 to more than 2.5 km³/year. This situation provoked risks of water salinisation, reduction of the artesianisme, an increase of drawdowns, etc. which seriously threaten the sustainable socioeconomic development engaged in the SASS zone. Face the water shortage induced by the alarming dryness noted these last years, particularly in the MENA region, the joint management of this system by the three concerned countries, engaged for many years, needs a long-term strategy of integrated water resources management to meet the expected socio-economic goals projected not only in the SASS zone but also in other places, by water transfers. The sustainable management of this extensive aquifer system, aiming to satisfy various needs not only in the areas covered by the SASS but also in other areas through hydraulic transfers, can only be considered if this management is genuinely coordinated, incorporating schemes that primarily address the major constraint of climate change, which has been observed worldwide over the past two decades and is intensifying. In this particular climate context, management schemes must necessarily target several aspects, including (i) Updating the state of water resource exploitation in the SASS. (ii) Guiding agricultural usage as the primary consumer to ensure significant water savings. (iii) Constant monitoring through a network of piezometers to control the physicochemical parameters of the exploited aquifers. (iv) Other aspects related to governance within the framework of integrated management must also be taken into consideration, particularly environmental aspects and conflict resolution. However, problems, especially political ones as currently seen in Libya, may limit or at least disrupt the prospects of coordinated and sustainable management of this aquifer system, which is vital for the three countries.

Keywords: transboundary water resources, SASS, governance, climatic changes

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Authors: C. N. Okafor, M. Maaza, T. A. E. Mokrani

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A proton exchange membrane has been developed for Direct Methanol Fuel Cell (DMFC). The nanofiber network composite membranes were prepared by interconnected network of Nafion (perfuorosulfonic acid) nanofibers that have been embedded in an uncharged and inert polymer matrix, by electro-spinning. The spinning solution of Nafion with a low concentration (1 wt. % compared to Nafion) of high molecular weight poly(ethylene oxide), as a carrier polymer. The interconnected network of Nafion nanofibers with average fiber diameter in the range of 160-700nm, were used to make the membranes, with the nanofiber occupying up to 85% of the membrane volume. The matrix polymer was cross-linked with Norland Optical Adhesive 63 under UV. The resulting membranes showed proton conductivity of 0.10 S/cm at 25°C and 80% RH; and methanol permeability of 3.6 x 10-6 cm2/s.

Keywords: composite membrane, electrospinning, fuel cell, nanofibers

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Authors: Mohit Batra, Noel Sarkar, Jayeeta Mitra

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In this study silica nanoparticles were synthesized using different methods and different silica sources namely Tetraethyl ortho silicate (TEOS), Sodium Silicate, Rice husk while chitosan nanoparticles were prepared with ionic gelation method using Sodium tripolyphosphate (TPP). Size and texture of silica nanoparticles were studied using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) along with the effect of change in concentration of various reagents in different synthesis processes. Size and dispersion of Silica nanoparticles prepared from TEOS using stobber’s method were found better than other methods while nanoparticles prepared using rice husk were cheaper than other ones. Catalyst found to play a very significant role in controlling the size of nanoparticles in all methods.

Keywords: silica nanoparticles, gelatin, bio-nanocomposites, SEM, TEM, chitosan

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Authors: Alireza Mohadesi, Ashraf Salmanipour

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A chemically modified glassy carbon electrode for electrocatalytic determination of sulfide was developed using multiwalled carbon nanotubes (MWCNTs) covalently immobilized with 2,6-dichlorophenolindophenol (DPIP). The immobilization of 2,6-dichlorophenolindophenol with MWCNTs was performed with a new synthetic strategy and characterized by UV–visible absorption spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry. The cyclic voltammetric response of DPIP grafted onto MWCNTs indicated that it promotes the low potential, sensitive and stable determination of sulfide. The dependence of response currents on the concentration of sulfide was examined and was linear in the range of 10 - 1100 µM. The detection limit of sulfide was 5 µM and RSD for 100 and 500 µM sulfides were 1.8 and 1.3 %. Many interfering species had little or no effect on the determination of sulfide. The procedure was applied to determination of sulfide in waters samples.

Keywords: functionalized carbon nanotubes, sulfide, biological samples, 2, 6-dichlorophenolindophenol

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Authors: Ke Wang, Zhu Wang

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Coordinating and promoting urban and rural development has been a new round of institutional change in Zhejiang province since 2004. And this plan was fully implemented, which showed that the isolation between the urban and rural areas had gradually diminished. Little by little, an infiltration interface that is dynamic, flexible and interactive is formed, and this morphological structure starts to appear on the landscape form in the surrounding villages. In order to study the specific function and formation of the structure in the context of industrial revolution, Bimen village located on the interface between Anji Township, Huzhou and Yuhang District, Hangzhou is taken as the case. Anji township is in the cross area between Yangtze River delta economic circle and innovation center in Hangzhou. Awarded with ‘Chinese beautiful village’, Bimen has witnessed the growing process of infiltration in ecology, economy, technology and culture on the interface. Within the opportunity, Bimen village presents internal reformation to adapt to the energy exchange with urban areas. In the research, the reformation is to adjust the industrial structure, to upgrade the local special bamboo crafts, to release space for activities, and to establish infrastructures on the interface. The characteristic of an interface is elasticity achieved by introducing an Internet platform using ‘O2O’ agriculture method to connect cities and farmlands. There is a platform of this kind in Bimen named ‘Xiao Mei’. ‘Xiao’ in Chinese means small, ‘Mei’ means beautiful, which indicates the method to refine the landscape form. It turns out that the new agriculture mode will strengthen the interface by orienting the Third Party Platform upon the old dynamic basis and will bring new vitality for economy development in Bimen village. The research concludes opportunities and challenges generated by the evolution of the infiltration interface. It also proposes strategies for how to organically adapt to the urbanization process. Finally it demonstrates what will happen by increasing flexibility in the landscape forms of suburbs in the Bimen village.

Keywords: Bimen village, infiltration interface, flexibility, suburban landscape form

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Authors: Vasant Reddy, Shivani A. Singh, Pravin S. More

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In the present investigation, we demonstrated the fabrication of few-layers of graphene sheets with alkali metal i.e. Rb-G using chemical route method. The obtained materials were characterized by means of chemical, structural and electrical techniques, using the ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and 4 points probe, respectively. The XRD studies were carried out to understand the phase of the samples where we found a sharp peak of Rb-G at 26.470. UV-Spectroscopy of Graphene and Rb-modified graphene samples shows the absorption peaks at ~248 nm and ~318 nm respectively. These analyses show that this modified material can be useful for gas sensing applications and to be used in diverse areas.

Keywords: chemical route, graphene, gas sensing, UV-spectroscopy

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Authors: Mahmoud Karimi, Golmohammad Khoobbakht

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This study focuses on the exergy flow analysis in the transesterification of waste cooking oil with methanol to decrease the consumption of materials and energy and promote the use of renewable resources. The exergy analysis performed is based on the thermodynamic performance parameters namely exergy destruction and exergy efficiency to investigate the effects of variable parameters on renewability of transesterification. The experiment variables were methanol to WCO ratio, catalyst concentration and reaction temperature in the transesterification reaction. The optimum condition with yield of 90.2% and exergy efficiency of 95.2% was obtained at methanol to oil molar ratio of 8:1, 1 wt.% of KOH, at 55 °C. In this condition, the total waste exergy was found to be 45.4 MJ for 1 kg biodiesel production. However high yield in the optimal condition resulted high exergy efficiency in the transesterification of WCO with methanol.

Keywords: biodiesel, exergy, thermodynamic analysis, transesterification, waste cooking oil

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Authors: Mogens Saberi

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The following article focuses on a new seismic design approach for Denmark. Denmark is located in a low seismic zone and up till now a general and very simplified approach has been used to accommodate the effect of seismic loading. The current used method is presented and it is found that the approach is on the unsafe side for many building types in Denmark. The damages during time due to earth quake is presented and a seismic map for Denmark is developed and presented. Furthermore, a new design approach is suggested and compared to the existing one. The new approach is relatively simple but captures the effect of seismic loading more realistic than the existing one. The new approach is believed to the incorporated in the Danish Deign Code for building structures.

Keywords: low seismicity, new design approach, earthquakes, Denmark

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Authors: Leal Leonardo, Pires Carlos Augusto de Moraes, Casiraghi Magela

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In this work were realized the modeling and simulation of the catalytic reformer process, of ample form, considering all the equipment that influence the operation performance. Considered it a semi-regenerative reformer, with four reactors in series intercalated with four furnaces, two heat exchanges, one product separator and one recycle compressor. A simplified reactional system was considered, involving only ten chemical compounds related through five reactions. The considered process was the applied to aromatics production (benzene, toluene, and xylene). The models developed to diverse equipment were interconnecting in a simulator that consists of a computer program elaborate in FORTRAN 77. The simulation of the global model representative of reformer unity achieved results that are compatibles with the literature ones. It was then possible to study the effects of operational variables in the products concentration and in the performance of the unity equipment.

Keywords: catalytic reforming, modeling, simulation, petrochemical engineering

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Authors: Ian Marc G. Cabugsa, Zarine M. Hermita

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Phytoextraction capability of T. catappa in contaminated soils was done in the improvised greenhouse. The plant samples were planted to the soil which contained different concentrations of copper. Chelating agent EDTA was added to observe the uptake and translocation of copper in the plant samples. Results showed a significant increase of copper accumulation with the addition of EDTA at 250 and 1250 mgˑkg-1 concentration of copper in the contaminated soils (p<0.05). While translocation of copper was observed in all treatments, translocation of copper is not significantly enhanced by the addition of EDTA (p>0.05). Uptake and translocation were not directly affected the presence of EDTA. Furthermore, this study suggests that the T. catappa is not a hyperaccumulator of copper, and there is no relationship observed between the length of the plant and the copper uptake in all treatments.

Keywords: chelating agent EDTA, hyperaccumulator, phytoextraction, phytoremediation, terminalia catappa

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Authors: Chih-Chi Cheng, Ji-Yu Lin, I-Ming Chu

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In this study, we synthesized a thermosensitive polypeptide hydrogel by copolymerizing poloxamer (PLX) and poly(ʟ-alanine) with ʟ-lysine segments at the both ends to form PLX-b-poly(ʟ-alanine-lysine) (Lys-Ala-PLX-Ala-Lys) copolymers. Poly(ʟ-alanine) is the hydrophobic chain of Lys-Ala-PLX-Ala-Lys copolymers which was designed to capture the hydrophobic agents. The synthesis was examined by 1H NMR and showed that Lys-Ala-PLX-Ala-Lys copolymers were successfully synthesized. At the concentration range of 3-7 wt%, the aqueous copolymer solution underwent sol-gel transition near the physiological temperature and exhibited changes in its secondary structure content, as evidenced by FTIR. The excellent viability of cells cultured within the scaffold was observed after 72 hr of incubation. Also, negatively charged bovine serum albumin was incorporated into the hydrogel without diminishing material integrity and shows good release profile. In the animal study, the results also indicated that Lys-Ala-PLX-Ala-Lys hydrogel has high potential in wound dressing.

Keywords: polypeptide thermosensitive hydrogel, tacrolimus, vascularized composite allotransplantation, sustain release

Procedia PDF Downloads 275

Authors: Saratu Yusuf Ilu, Mumtaz B. Mustafa, Siti Salwah Salim, Mehdi Malekzadeh

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Children today use computer based application in various activities especially for learning and education. Many of these tools and application such as the Computer Aided Pronunciation Training (CAPT) system enable children to explore and experience them with little supervision from the adults. In order for these tools and application to have maximum effect on the children’s learning and education, it must be attractive to the children to use them. This could be achieved with the proper user interface (UI) design. As children grow, so do their ability, taste and preferences. They interact differently with these applications as they grow older. This study reviews several articles on how age factor influences the UI design. The review focuses on age related abilities such as cognitive, literacy, concentration and feedback requirement. We have also evaluated few of existing CAPT systems and determine the influence of age-based factors on the interface design.

Keywords: children, age-based interaction, learning application, age-based capability

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Authors: Fumane Portia Khanare

Abstract:

This paper explores strategies to improve the psychosocial wellbeing of orphans and vulnerable learners (OVLs) in rural schools in Lesotho that seem essential for their success, in anticipation of, and in the context of global education. Various strategies to improve psychosocial wellbeing are considered necessary in that they are inclusive and buffer other forms of conditions beyond traditional and Eurocentric forms in orientation. Furthermore, they bring about the local experiences and particularly of the learners and schools in rural areas – all of which constitute ethnopsychology. COVID-19 pandemic has enthused the demands for collaboration and responsive support for learners within rural and many deprived contexts in Lesotho. However, the increase of OVLs in the education sector has also sparked the debate of how many rural schools with a lack of resources, inadequate teacher training, declining unemployment and the detriment of COVID-19 throughout Lesotho affected the psychosocial wellbeing of these learners. In some cases, the pandemic has created opportunities to explore existing, forgotten or ignored resources dated back to the pre-colonial era in Lesotho, and emphasizing to have an optimistic outlook on life as a result of collaboration and appreciating local knowledge. In order to scale up the psychosocial wellbeing of OVLs, there is a need to explore various strategies to improve their psychosocial wellbeing, in which all learners can succeed during the COVID-19 pandemic and beyond, thereby promoting the agency of young people from the rural areas towards building supportive learning environments. The paper draws on qualitative participatory arts-based study data generated by 30 learners in two rural secondary schools in Lesotho. Thematic analysis was employed to provide an in-depth understanding of learners' psychosocial needs and strategies to improve their psychosocial wellbeing. The paper is guided by ethnopsychology – a strength-based perspective, which posits that in the most difficult situations, individuals including, young people have strengths, can collaborate and find solutions that respond to their challenges. This was done by examining how various facets of their environments such as peers, teachers, schools’ environment, family and community played out in creating supportive strategies to improve the psychosocial wellbeing of OVLs which buffer the successful completion of their secondary school education. It is recommended that ethnopsychology should recognise and be used under the realm of positive wellbeing in rural schools in Lesotho.

Keywords: arts-based research, ethnopsychology, Lesotho, orphans and vulnerable learners, psychosocial wellbeing, rural schools.

Procedia PDF Downloads 184

Authors: Fumane Portia Khanare

Abstract:

This paper explores strategies to improve the psychosocial wellbeing of orphans and vulnerable learners (OVLs) in rural schools in Lesotho that seem essential for their success, in anticipation of, and in the context of global education. Various strategies to improve the psychosocial wellbeing are considered necessary in that they are inclusive and buffer other forms of conditions beyond traditional and Eurocentric forms in orientation. Furthermore, they bring about the local experiences and particularly of the learners and schools in rural areas – all of which constitute ethnopsychology. COVID-19 pandemic has enthused the demands for collaboration and responsive support for learners within rural and many deprived contexts in Lesotho. However, the increase of OVLs in the education sector has also sparked the debate of how much rural schools with lack of resources, inadequate teacher training, declining unemployment and the detriment of COVID-19 throughout Lesotho affected the psychosocial wellbeing of these learners. In some cases, the pandemic has created opportunities to explore existing, forgotten or ignored resources dated back to pre-colonial era in Lesotho, and emphasizing to have an optimistic outlook on life as a result of collaboration and appreciating local knowledge. In order to scale up the psychosocial wellbeing of OVLs there is a need to explore various strategies to improve their psychosocial wellbeing, in which all learners can succeed during COVID-19 pandemic and beyond, thereby promoting agency of young people from the rural areas towards building supportive learning environments. The paper draws on a qualitative participatory arts-based study data generated by 30 learners in two rural secondary schools in Lesotho. Thematic analysis was employed to provide an in-depth understanding of learners' psychosocial needs and strategies to improve their psychosocial wellbeing. The paper is guided by ethnopsychology – a strength-based perspective, which posit that in the most difficult situations, individual including, young people have strengths, can collaborate and find solutions that respond to their challenges. This was done by examining how various facets of their environments such as peers, teachers, schools’ environment, family and community played out in creating supportive strategies to improve the psychosocial wellbeing of OVLs which buffer their successful completion of their secondary school education. It is recommended that ethnopsychology should recognised and be used under the realm of positive wellbeing in rural schools in Lesotho.

Keywords: arts-based research, ethnopsychology, orphans and vulnerable learners, Lesotho, psychosocial wellbeing, rural schools

Procedia PDF Downloads 126

Authors: T. Mersmann, P. Nyhuis

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In the current economic climate, for many businesses it is generally no longer sufficient to pursue exclusively economic interests. Instead, integrating ecological and social goals into the corporate targets is becoming ever more important. However, the holistic integration of these new goals is missing from current factory planning approaches. This article describes the conceptual framework for a planning methodology for sustainable factories. To this end, the description of the key areas for action is followed by a description of the principal components for the systematization of sustainability for factories and their stakeholders. Finally, a conceptual framework is presented which integrates the components formulated into an established factory planning procedure.

Keywords: factory planning, stakeholder, systematization, sustainability

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Authors: K. Abbas, R. Ahmad, I. A. Khan, S. Saleem, U. Ikhlaq

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Nitriding of p-type Si samples by pulsed DC glow discharge is carried out for different Ar concentrations (30% to 90%) in nitrogen-argon plasma whereas the other parameters like pressure (2 mbar), treatment time (4 hr) and power (175 W) are kept constant. The phase identification, crystal structure, crystallinity, chemical composition, surface morphology and topography of the nitrided layer are studied using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), optical microscopy (OM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively. The XRD patterns reveal the development of different diffraction planes of Si₃N₄ confirming the formation of polycrystalline layer. FTIR spectrum confirms the formation of bond between Si and N. Results reveal that addition of Ar into N₂ plasma plays an important role to enhance the production of active species which facilitate the nitrogen diffusion.

Keywords: crystallinity, glow discharge, nitriding, sputtering

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Authors: Nidal H. Abu-Zahra, Mahmoud Algazzar

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In this research, n-dodecylthiol was added to P3HT/PC70BM polymer solar cells to improve the crystallinity of P3HT and enhance the phase separation of P3HT/PC70BM. The improved crystallinity of P3HT/PC70BM doped with 0-5% by volume of n-dodecylthiol resulted in improving the power conversion efficiency of polymer solar cells by 33%. In addition, thermal annealing of the P3HT/PC70MB/n-dodecylthiolcompound showed further improvement in crystallinity with n-dodecylthiol concentration up to 2%. The highest power conversion efficiency of 3.21% was achieved with polymer crystallites size L of 11.2nm, after annealing at 150°C for 30 minutes under a vacuum atmosphere. The smaller crystallite size suggests a shorter path of the charge carriers between P3HT backbones, which could be beneficial to getting a higher short circuit current in the devices made with the additive.

Keywords: n-dodecylthiol, congugated PSC, P3HT/PCBM, polymer solar cells

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Authors: Akarsh Verma, Avinash Parashar

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The aim of this article is to study the effects of hydroxyl functional group on the mechanical strength and fracture toughness of graphene. This functional group forms the backbone of intrinsic atomic structure of graphene oxide (GO). Molecular dynamics-based simulations were performed in conjunction with reactive force field (ReaxFF) parameters to capture the mode-I fracture toughness of hydroxyl functionalised graphene. Moreover, these simulations helped in concluding that spatial distribution and concentration of hydroxyl functional group significantly affects the fracture morphology of graphene nanosheet. In contrast to literature investigations, atomistic simulations predicted a transition in the failure morphology of hydroxyl functionalised graphene from brittle to ductile as a function of its spatial distribution on graphene sheet.

Keywords: graphene, graphene oxide, ReaxFF, molecular dynamics

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Authors: Sophio Kobauri, Vladimir P. Torchilin, David Tugushi, Ramaz Katsarava

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Nanotherapy is an actual newest mode of treatment numerous diseases using nanoparticles (NPs) loading with different pharmaceuticals. NPs of biodegradable polymeric micelles (PMs) are gaining increased attention for their numerous and attractive abilities to be used in a variety of applications in the various fields of medicine. The present paper deals with the synthesis of a class of biodegradable micelle-forming polymers, namely ABA triblock-copolymer in which A-blocks represent amino-poly(ethylene glycol) (H₂N-PEG) and B-block is biodegradable amino acid-based poly(ester amide) constituted of α-amino acid – L-phenylalanine. The obtained copolymer formed micelles of 70±4 nm size at 10 mg/mL concentration.

Keywords: amino acids, biodegradable poly (ester amide), amphiphilic triblock-copolymer, micelles

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Authors: Hugo Manoel Olivera Da Silva, Ricardo Silva Thé Pontes

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In this work, is presented an analysis of the Brazilian regulation on human exposure to electromagnetic fields, which provides limits to electric fields, magnetic and electromagnetic fields. The regulations for the electricity sector was in charge of the Agência Nacional de Energia Elétrica-ANEEL, the Brazilian Electricity Regulatory Agency, that made it through the Normative Resolution Nº 398/2010, resulting in a series of obligations for the agents of the electricity sector, especially in the areas of generation, transmission, and distribution.

Keywords: adverse effects, electric energy, electric and magnetic fields, human health, regulation

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Authors: Preethi Kumari P., Shetty Prakasha, Rao Suma A.

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Mild steel has been widely employed as construction materials for pipe work in the oil and gas production such as down hole tubular, flow lines and transmission pipelines, in chemical and allied industries for handling acids, alkalis and salt solutions due to its excellent mechanical property and low cost. Acid solutions are widely used for removal of undesirable scale and rust in many industrial processes. Among the commercially available acids hydrochloric acid is widely used for pickling, cleaning, de-scaling and acidization of oil process. Mild steel exhibits poor corrosion resistance in presence of hydrochloric acid. The high reactivity of mild steel in presence of hydrochloric acid is due to the soluble nature of ferrous chloride formed and the cementite phase (Fe3C) normally present in the steel is also readily soluble in hydrochloric acid. Pitting attack is also reported to be a major form of corrosion in mild steel in the presence of high concentrations of acids and thereby causing the complete destruction of metal. Hydrogen from acid reacts with the metal surface and makes it brittle and causes cracks, which leads to pitting type of corrosion. The use of chemical inhibitor to minimize the rate of corrosion has been considered to be the first line of defense against corrosion. In spite of long history of corrosion inhibition, a highly efficient and durable inhibitor that can completely protect mild steel in aggressive environment is yet to be realized. It is clear from the literature review that there is ample scope for the development of new organic inhibitors, which can be conveniently synthesized from relatively cheap raw materials and provide good inhibition efficiency with least risk of environmental pollution. The aim of the present work is to evaluate the electrochemical parameters for the corrosion inhibition behavior of an aromatic hydrazide derivative, 4-hydroxy- N '-[(E)-1H-indole-2-ylmethylidene)] benzohydrazide (HIBH) on mild steel in 2M hydrochloric acid using Tafel polarization and electrochemical impedance spectroscopy (EIS) techniques at 30-60 °C. The results showed that inhibition efficiency increased with increase in inhibitor concentration and decreased marginally with increase in temperature. HIBH showed a maximum inhibition efficiency of 95 % at 8×10-4 M concentration at 30 °C. Polarization curves showed that HIBH act as a mixed-type inhibitor. The adsorption of HIBH on mild steel surface obeys the Langmuir adsorption isotherm. The adsorption process of HIBH at the mild steel/hydrochloric acid solution interface followed mixed adsorption with predominantly physisorption at lower temperature and chemisorption at higher temperature. Thermodynamic parameters for the adsorption process and kinetic parameters for the metal dissolution reaction were determined.

Keywords: electrochemical parameters, EIS, mild steel, tafel polarization

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Authors: A. Boveiri Monji, H. Yousefnia, M. Haji Hosseini, S. Zolghadri

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A clean spectrophotometric method for the determination of hafnium by using a green reagent, acidic extract of Ficus carica tree leaves is developed. In 6-M hydrochloric acid, hafnium reacts with this reagent to form a yellow product. The formed product shows maximum absorbance at 421 nm with a molar absorptivity value of 0.28 × 104 l mol⁻¹ cm⁻¹, and the method was linear in the 2-11 µg ml⁻¹ concentration range. The detection limit value was found to be 0.312 µg ml⁻¹. Except zirconium and iron, the selectivity was good, and most of the ions did not show any significant spectral interference at concentrations up to several hundred times. The proposed method was green, simple, low cost, and selective.

Keywords: spectrophotometric determination, Ficus caricatree leaves, synthetic reagents, hafnium

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Authors: Daniel Y. Abebe, Jaehyouk Choi

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The objective of this paper is to investigate, through an analytical study, the behavior of both stiffened and un-stiffened removable shear link with perforated web considering different number and size of web openings. Removable shear link with perforated web is a novel shear link beam proposed to be used in eccentrically braced frame (EBF). The proposed link overcomes the difficulties during construction slab due to less cross-sectional areas of the link to control the plastic deformation on the conventional EBF with removable shear link. Finite element analyses were conducted under both cyclic and monotonic loading and from the results obtained design equations are developed.

Keywords: eccentrically braced frame, removable shear link, perforated web, non-linear FE analysis

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Authors: Jongho Park, Taekyun Kim, Jungbhin You, Sungnam Hong, Sun-Kyu Park

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Due to the aging of bridges, increasing of maintenance costs and decreasing of structural safety is occurred. The steel corrosion of reinforced concrete bridge is the most common problem and this phenomenon is accelerating due to abnormal weather and increasing CO₂ concentration due to climate change. To solve these problems, composite members using textile have been studied. A textile reinforced concrete can reduce carbon emissions by reduced concrete and without steel bars, so a lot of structural behavior studies are needed. Therefore, in this study, textile reinforced concrete beam was made and flexural test was performed. Also, the change of flexural strength according to the prestressing was conducted. As a result, flexural strength of TRC with prestressing was increased compared and flexural behavior was shown as reinforced concrete.

Keywords: AR-glass, flexural strength, prestressing, textile reinforced concrete

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Authors: Allaw Kamel, Bazzi Hasan

Abstract:

Municipal solid waste (MSW) generation is among the most significant sources which threaten the global environmental health. Solid Waste Management has been an important environmental problem in developing countries because of the difficulties in finding sustainable solutions for solid wastes. Therefore, more efforts are needed to be implemented to overcome this problem. Lebanon has suffered a severe solid waste management problem in 2015, and a new landfill site was proposed to solve the existing problem. The study aims to identify and locate the most suitable area to construct a landfill taking into consideration the sustainable development to overcome the present situation and protect the future demands. Throughout the article, a landfill site selection methodology was discussed using Geographic Information System (GIS) and Multi Criteria Decision Analysis (MCDA). Several environmental, economic and social factors were taken as criterion for selection of a landfill. Soil, geology, and LUC (Land Use and Land Cover) indices with the Sustainable Development Index were main inputs to create the final map of Environmentally Sensitive Area (ESA) for landfill site. Different factors were determined to define each index. Input data of each factor was managed, visualized and analyzed using GIS. GIS was used as an important tool to identify suitable areas for landfill. Spatial Analysis (SA), Analysis and Management GIS tools were implemented to produce input maps capable of identifying suitable areas related to each index. Weight has been assigned to each factor in the same index, and the main weights were assigned to each index used. The combination of the different indices map generates the final output map of ESA. The output map was reclassified into three suitability classes of low, moderate, and high suitability. Results showed different locations suitable for the construction of a landfill. Results also reflected the importance of GIS and MCDA in helping decision makers finding a solution of solid wastes by a sanitary landfill.

Keywords: sustainable development, landfill, municipal solid waste (MSW), geographic information system (GIS), multi criteria decision analysis (MCDA), environmentally sensitive area (ESA)

Procedia PDF Downloads 137

Authors: Yamina Zouambia, Khadidja Youcef Ettoumi, Mohamed Krea, Nadji Moulai Mostefa

Abstract:

Environment pollution through various wastes (particularly by heavy metals) is a major environmental problem due to industrialization and the development of various human activities. Considerable attention has been focused, in recent years, upon the field of biosorption which represents a biotechnological innovation as well as an excellent tool for removal of metal ions from aqueous effluents. So the purpose of this study is to valorize by-product which are orange peels and an extract of these peels (pectin; a heteropolysaccharide) in treatment of water containing heavy metals. All biosorption experiments were carried out at room temperature, an indicated pH, a precise amount of biosorbent and under continuous stirring. Biosorption kinetic was determined by evaluating the residual concentration of the metal ion at different time intervals using UV spectroscopy. The results obtained show that the orange peels and pectin are interesting biosorbents with maximum biosorption capacity of up to 140 mg/g.

Keywords: orange peels, pectin, heavy metals, biosorption

Procedia PDF Downloads 319

Authors: Mohamad Musa, Khaldoun Aldiabat, Chelsea McLellan

Abstract:

In higher education, academic advising and counseling are pivotal for guiding students towards successful academic and professional trajectories. Within this landscape, professors play a critical role as academic advisors, offering guidance and support to students navigating their educational journey. This study endeavors to delve into the effectiveness of professors in this capacity through a comprehensive quantitative survey. Amidst the research objectives lies a profound exploration of students' perceptions regarding professors' effectiveness as academic advisors. Additionally, the study aims to elucidate the nuanced strengths and limitations inherent in professors' advisory roles. Through meticulous examination, the research seeks to uncover the profound impact of professors' engagement on student academic accomplishments and contentment. Moreover, it will scrutinize the requisite qualifications, training, and support mechanisms necessary for professors to excel in advisory roles. Utilizing a quantitative survey methodology, this research will gather invaluable insights into students' perspectives on professors' advisory competencies. Rigorous statistical analysis of survey responses will illuminate the efficacy of professors as academic advisors. The survey instrument will intricately measure diverse dimensions such as students' satisfaction levels with advisory sessions, the perceived efficacy of advice rendered by professors, and the holistic influence of professors' involvement on academic triumphs. Anticipated outcomes encompass a meticulous quantitative evaluation of professors' efficacy in academic advisory roles. Moreover, the research endeavors to delineate areas of proficiency and areas necessitating refinement within professors' advisory practices. Through these efforts, the study aims to provide valuable insights that can inform strategies for enhancing professors' advisory practices and optimizing the support systems available to students in higher education institutions. The study seeks to go beyond surface-level evaluations by delving into the intricate relationship between professors' involvement in academic advising and student academic outcomes. By unraveling this complex interplay, the research endeavors to shed light on the mechanisms through which professors' guidance impacts students' academic success, satisfaction, and overall educational experience.

Keywords: academic advising, professors, effectiveness, quantitative survey, student outcomes

Procedia PDF Downloads 28