Search results for: small and medium sized enterprises (SMEs)

Authors: J. Iwaro, A. Mwasha, K. Ramsubhag

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Global warming has become a threat of our time. It poses challenges to the existence of beings on earth, the built environment, natural environment and has made a clear impact on the level of energy and water consumption. As such, increase in the ambient temperature increases indoor and outdoor temperature level of the buildings which brings about the use of more energy and mechanical air conditioning systems. In addition, in view of the increased modernization and economic growth in the developing countries, a significant amount of energy is being used, especially those with hot climatic conditions. Since modernization in developing countries is rising rapidly, more pressure is being placed on the buildings and energy resources to satisfy the indoor comfort requirements. This paper presents a sustainable passive roof solution as a means of reducing energy cooling loads for satisfying human comfort requirements in a hot climate. As such, the study based on the field study data discusses indoor thermal roof design strategies for a hot climate by investigating the impacts of roof thermal performance on indoor thermal comfort in naturally ventilated building envelope small scaled structures. In this respect, the traditional concrete flat roof, corrugated galvanised iron roof and pre-painted standing seam roof were used. The experiment made used of three identical small scale physical models constructed and sited on the roof of a building at the University of the West Indies. The results show that the utilization of insulation in traditional roofing systems will significantly reduce heat transfer between the internal and ambient environment, thus reducing the energy demand of the structure and the relative carbon footprint of a structure per unit area over its lifetime. Also, the application of flat slab concrete roofing system showed the best performance as opposed to the metal roof sheeting alternative systems. In addition, it has been shown experimentally through this study that a sustainable passive roof solution such as insulated flat concrete roof in hot dry climate has a better cooling strength that can provide building occupant with a better thermal comfort, conducive indoor conditions and energy efficiency.

Keywords: building envelope, roof, energy consumption, thermal comfort

Procedia PDF Downloads 258

Authors: Tshaudi Motsima

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Class attendance is key at all levels of education. At tertiary level many students develop a tendency of not attending all classes without being aware of the repercussions of not attending all classes. It is important for all students to attend all classes as they can receive first-hand information and they can benefit more. The student who attends classes is likely to perform better academically than the student who does not. The aim of this paper is to assess the relationship between class attendance and academic performance of industrial engineering students. The data for this study were collected through the attendance register of students and the other data were accessed from the Integrated Tertiary Software and the Higher Education Data Analyzer Portal. Data analysis was conducted on a sample of 93 students. The results revealed that students with medium predicate scores (OR = 3.8; p = 0.027) and students with low predicate scores (OR = 21.4, p < 0.001) were significantly likely to attend less than 80% of the classes as compared to students with high predicate scores. Students with examination performance of less than 50% were likely to attend less than 80% of classes than students with examination performance of 50% and above, but the differences were not statistically significant (OR = 1.3; p = 0.750).

Keywords: class attendance, examination performance, final outcome, logistic regression

Procedia PDF Downloads 123

Authors: Hanan Moawad, Naglaa M. Abd EL-Rahman

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Erwinia carotovora var. carotovora is the main cause of soft rot in potatoes. Hyphaene thebaica was studied for biocontrol of E. carotovora which inhibited growth of E. carotovora on solid medium, a comparative study of classical and ultrasound-assisted extractions of Hyphaene thebaica fruit. The use of ultrasound decreased significant the total time of treatment and increase the total amount of crude extract. The crude extract was subjected to determine the in vitro, by a bioassay technique revealed that the treatment of paper disks with ultrasound extraction of Hyphaene thebaica reduced the growth of pathogen and produced inhibition zones up to 38mm in diameter. The antioxidant activity of ultrasound-ethanolic extract of Doum fruits (Hyphaene thebaica) was determined. Data obtained showed that the extract contains the secondary metabolites such as Tannins, Saponin, Flavonoids, Phenols, Steroids, Terpenoids, Glycosides and Alkaloids.

Keywords: ultrasound, classical extract, biological control, Erwinia carotovora, Hyphaene thebaica

Procedia PDF Downloads 506

Authors: Desta Gebretekle Shiferaw, Balakrishna Kalluraya

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Pyrazole is an aromatic five-membered heterocycle with two nitrogen and three carbon atoms in its ring structure. According to the literature, pyrazoline, pyrazole, and thiazole-containing moieties are found in various drug structures and are responsible for nearly all pharmacological effects. The pyrazoline linked to pyrazole moiety carbothioamides was synthesized via the reaction of pyrazole-bearing chalcones (3-(5-chloro-3-methyl-¹-phenyl-1H-pyrazol-4-yl)-¹-(substituted aryl) prop-2-ene-¹-one derivatives) with a nucleophile thiosemicarbohyrazide by heating in ethanol using fused sodium acetate as a catalyst. Then the carbothioamide derivatives were converted into the pyrazoline hybrid to pyrazole and thiazole derivatives by condensing with substituted phenacyl bromide in alcohol in a basic medium. Next, the chemical structure of the newly synthesized molecules was confirmed by IR, 1H-NMR, and mass spectral data. Further, they were screened for their in vitro antioxidant activity. Compared to butylated hydroxy anisole (BHA)., the antioxidant data showed that the synthesized compounds had good to moderate activity.

Keywords: pyrazoline-pyrazole carbothioamide derivatives, pyrazoline-pyrazole-thiazole derivatives, spectral studies, antioxidant activity

Procedia PDF Downloads 58

Authors: Virginia Melnyk

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This paper explores the design for catenary structure using knitted textiles. Using the advantages of Grasshopper and Kangaroo parametric software to simulate and pre-design an overall form, the design is then translated to a pattern that can be made with hand manipulated stitches on a knitting machine. The textile takes advantage of the structure of knitted materials and the ability for it to stretch. Using different types of stitches to control the amount of stretch that can occur in portions of the textile generates an overall formal design. The textile is then hardened in an upside-down hanging position and then flipped right-side-up. This then becomes a structural catenary form. The resulting design is used as a small Cat House for a cat to sit inside and climb on top of.

Keywords: architectural materials, catenary structures, knitting fabrication, textile design

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Authors: Ioanna H. Lioliou, Despoina D. Zavraka

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The radical reformation that Greek urban space, has undergone over the last century, due to the socio-historical developments, technological development and political–geographic factors, has left its imprint on the urban landscape. While the big cities struggle to regain urban landscape balance, small towns are considered to offer high quality lifescapes, ensuring sustainable development potential. However, their unplanned urbanization process led to the loss of significant areas of nature, lack of essential infrastructure, chaotic built environment, incompatible land uses and urban cohesiveness. Natural environment reference points, such as springs, streams, rivers, forests, suburban greenbelts, and etc.; seems to be detached from urban space, while the public, open and green spaces, unequally distributed in the built environment, they are no longer able to offer a complete experience of nature in the city. This study focuses on Greek mainland, a small town Elassona, and aims to restore spatial coherence between the city’s homonymous river and its urban space surroundings. The existence of a linear aquatic ecosystem, is considered a precious greenway, also referred as blueway, able to initiate natural penetrations and ecosystems empowering. The integration of disconnected natural ecosystems forms the basis of a strategic intervention scheme, where the river becomes the urban integration tool / feature, constituting the main urban corridor and an indispensible part of a wider green network that connects open and green spaces, ensuring the function of all the established networks (transportation, commercial, social) of the town. The proposed intervention, introduces a green network highlighting the old stone bridge at the ‘entrance’ of the river in the town and expanding throughout the town with strategic uses and activities, providing accessibility for all the users. The methodology used, is based on the collection of design tools used in related urban river-design interventions around the world. The reinstallation/reactivation of the balance between natural and urban landscape, besides the environmental benefits, contributes decisively to the illustration/projection of urban green identity and re-enhancement of the quality of lifescape qualities and social interaction.

Keywords: green network, rehabilitation scheme, urban landscape, urban streams

Procedia PDF Downloads 267

Authors: P. H. Mukti, I. Kurniawati, F. Oktaviansyah, A. D. Adhitya, N. Rachmadani, R. Corputty, G. Hendrantoro, T. Fukusako

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HF Communication system is one of the attractive fields among many researchers since it can be reached long-distance areas with low-cost. This long-distance communication can be achieved by exploiting the ionosphere as a transmission medium for the HF radio wave. However, due to the dynamic nature of ionosphere, the channel characteristic of HF communication has to be investigated in order to gives better performances. Many techniques to characterize HF channel are available in the literature. However, none of those techniques describe the HF channel characteristic in low-latitude regions, especially equatorial areas. Since the ionosphere around equatorial region has an ESF phenomenon, it becomes an important investigation to characterize the wideband HF Channel in low-latitude region. On the other sides, the appearance of software-defined radio attracts the interest of many researchers. Accordingly, in this paper a SDR-based channel measurement system is proposed to be used for characterizing the HF channel in low-latitude region.

Keywords: channel characteristic, HF communication system, LabVIEW, software-defined radio, universal software radio peripheral

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Authors: Albert Herve Nkolo Mpoko

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The Foreign Direct Investment (FDI) landscape in Cameroon has garnered significant attention from both European and Asian nations due to perceived benefits such as capital infusion, technology transfer, and potential for economic expansion. However, it is noteworthy that South Africa's investment presence remains comparatively subdued in Cameroon, lagging behind that of Europe and Asia. Equally surprising is the limited footprint of Africa's economic powerhouse within other African economies. This study delved into four specific facets of South African investment in Cameroon. Initially, it focused on identifying South African companies operating within Cameroon. Subsequently, the analysis encompassed assessing the correlation between South African investment and poverty alleviation. Additionally, the study examined the nexus between South African investment and technological advancement, and underscored the significance of investment incentives in both countries Key findings of the research shed light on several crucial points. South Africa ought to reassess its economic engagement with Francophone Africa, particularly Cameroon. Despite existing policies aimed at fostering investment, there remains substantial ground to cover in this realm. The proliferation of South African enterprises in Cameroon holds the potential to ameliorate poverty and foster employment opportunities across both nations. The advent of South African firms in Cameroon can catalyse technological advancements within the region. Data collection involved surveying 100 executives from the respective administrations and conducting ten interviews. The gathered data underwent triangulation, wherein quantitative findings were juxtaposed with qualitative insights. In conclusion, the study underscores the underutilization of Cameroon by South Africa, emphasizing the untapped potential for mutual economic growth. Furthermore, it posits that the success of South Africa's multinational corporations abroad could serve as a pivotal pillar for sustaining its domestic economy.

Keywords: FDI, transfer of technology, South-South cooperation, mutual economic growth

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Authors: Tappei Yotsumoto, Atsushi Nomura, Kozo Tanigawa, Kenichi Takahashi, Takao Kawamura, Kazunori Sugahara

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In a human tracking system, expanding a monitoring range of one system is complicating the management of devices and increasing its cost. Therefore, we propose a method to realize a wide-range human tracking by connecting small systems. In this paper, we examined an agent deploy method and information contents across the heterogeneous human tracking systems. By implementing the proposed method, we can construct a human tracking system across heterogeneous systems, and the system can track a target continuously between systems.

Keywords: human tracking system, mobile agent, monitoring, heterogeneous systems

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Authors: Sonia Wahengbam, Natasha Elangbam

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Female impersonation has existed through the length of human civilization and the breadth of its cultures. Transvestism and drag queen cultures have created multi-sited spaces where in the shadow of art, one can cross the gender barrier and express one’s hidden identity. This paper will explore a dynamic cultural space that exists in Manipur, a state in the northeastern region of India, where the female impersonators (nupi shabis) of a folk theater (Shumang Leela) are using this traditional and popular art form to claim social acceptance of their homosexual identities through the medium of entertainment. It will highlight how by crossing the gender boundary, this third gender group has carved out a unique socio-economic niche where they have exploited their sexual identities to their advantage. The paper will trace the expanding cultural ‘’borderland’’ of Manipur where there is an increasing sense of ‘becoming’, belonging and sharing” of identities through the interweaving of old and new media. The research will be based on interviews with the nupi shabis, cultural critics and other experts.

Keywords: transvestism, Manipur, female impersonators (nupi shabis), Shumang Leela, gender

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Authors: Mohamed M. Shahin

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This study investigated the design of the pile foundation to support heavy structures-especially bridges for highways-in the Sahara, which contains many dunes of medium dense sand in different levels, where the foundation is supposed to be piles. The base resistance of smooth model pile groups in sand under static loading is investigated experimentally in a pile soil test apparatus. Improvement were made to the sand around the piles in order to increase the shaft resistance of the single pile and the pile groups, and also base resistance especially for the central pile in pile groups. The study outlines the behaviour of a single-pile, 4-, 5-, and 9- pile groups arranged in a doubly symmetric [square] layout with different embedment lengths and pile spacing in loose dry sand [normal] and dense dry sand [compacted] around the piles. This study evaluate the variation of the magnitude and the proportion of end bearing capacity of individual piles in different pile groups. Also to investigate the magnitude of the efficiency coefficient in the case of different pile groups.

Keywords: pile group, base resistance, efficiency coefficient, pile spacing, pile-soil interaction

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Authors: El Korchi Ayoub, Cherif Raef

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Interior noise in vehicles is an essential factor affecting occupant comfort. Over recent decades, much work has been done to develop simulation tools for vehicle NVH. At the medium high-frequency range, the statistical energy analysis method (SEA) shows significant effectiveness in predicting noise and vibration responses of mechanical systems. In this paper, the evaluation of the sound pressure level (SPL) inside an automobile cabin has been performed numerically using the statistical energy analysis (SEA) method. A test car cabin was performed using a monopole source as a sound source. The decay rate method was employed to obtain the damping loss factor (DLF) of each subsystem of the developed SEA model. These parameters were then used to predict the sound pressure level in the interior cabin. The results show satisfactory agreement with the directly measured SPL. The developed SEA vehicle model can be used in early design phases and allows the engineer to identify sources contributing to the total noise and transmission paths.

Keywords: SEA, SPL, DLF, NVH

Procedia PDF Downloads 79

Authors: Emma Van Schie

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The purpose of this study is to use mixed methods research to create typologies of the performance of firms in the cotton-to-clothing value chain in Zimbabwe, and to use these typologies to achieve the objective of adding to the small pool of studies on Sub-Saharan African value chains performing in the context of economic liberalisation and achieving development. The uptake of economic liberalisation measures across Sub-Saharan Africa has led to the restructuring of many value chains. While this action has resulted in some African economies positively reintegrating into global commodity chains, it has also been deeply problematic for the development impacts of the majority of others. Over and above this, these nations have been placed at a disadvantage due to the fact that there is little scholarly and policy research on approaches for managing economic liberalisation and value chain development in the unique African context. As such, the central question facing these less successful cases is how they can integrate into the world economy whilst still fostering their development. This paper draws from quantitative questionnaires and qualitative interviews with 28 stakeholders in the cotton-to-clothing value chain in Zimbabwe. This paper examines the performance of firms in the value chain, and the subsequent local socio-economic development impacts that are affected by the revival of the cotton-to-clothing value chain following its collapse in the wake of Zimbabwe’s uptake of economic liberalisation measures. Firstly, the paper finds the relatively undocumented characteristics and structures of firms in the value chain in the post-economic liberalisation era. As well as this, it finds typologies of the status of firms as either being in operation, closed down, or being placed under judicial management and the common characteristics that these typologies hold. The key findings show how a mixture of macro and local level aspects, such as value chain governance and the management structure of a business, leads to the most successful typology that is able to add value to the chain in the context of economic liberalisation, and thus unlock its socioeconomic development potential. These typologies are used in making industry and policy recommendations on achieving this balance between the macro and the local level, as well as recommendations for further academic research for more typologies and models on the case of cotton value chains in Sub-Saharan Africa. In doing so, this study adds to the small collection of academic evidence and policy recommendations for the challenges that African nations face when trying to incorporate into global commodity chains in attempts to benefit from their associated socioeconomic development opportunities.

Keywords: cotton-to-clothing value chain, economic liberalisation, restructuring value chain, typologies of firms, value chain governance, Zimbabwe

Procedia PDF Downloads 155

Authors: Megha Chavda, Parth Thummar, Rahul Ghetia

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This paper presents the voltage and current control of microgrid accompanied by the synchronization of microgrid with the main utility grid in both islanded and grid-connected modes. Distributed Energy Resources (DERs) satisfy the wide-spread power demand of consumer by behaving as a micro source for a low voltage (LV) grid or microgrid. Synchronization of the microgrid with the main utility grid is done using PLL and PWM gate pulse generation technique is used for the Voltage Source Converter. Potential Function method achieves the voltage and current control of this microgrid in both islanded and grid-connected modes. A low voltage grid consisting of three distributed generators (DG) is considered for the study and is simulated in time-domain using PSCAD/EMTDC software. The simulation results depict the appropriateness of voltage and current control of microgrid and synchronization of microgrid with the medium voltage (MV) grid.

Keywords: microgrid, distributed energy resources, voltage and current control, voltage source converter, pulse width modulation, phase locked loop

Procedia PDF Downloads 397

Authors: Ahmad Bilal

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Digital and convergent media can be helpful in terms of acquiring film production skills and knowledge, and it has also reduced the cost of production. Thus, allowing filmmakers greater opportunities and access to the medium of film. Both these dimensions of new and convergent media have been challenging the established cinema of Pakistan, as traditionally, it has been controlled by the authorities through censorship policies. The use of the smartphone as a movie camera, editing machine, and a transmitter can further challenge the control in a postcolonial society. To explore the impact of new and convergent media on the art of filmmaking, a film 'Sohni Dharti: An untrue story' is produced. It is shot both on a smartphone and a Digital Single Lens Reflex Camera (DSLR), with almost zero budgets. It is distributed through Vimeo from Pakistan. This process reveals how the technologies that are available today, and the increased knowledge of film production that they bring, allow a more inclusive experience of the film production and distribution. At the same time, however, it also discloses the limitations that accompany new technologies within the context of a postcolonial society. This paper will investigate the role of technology to bring filmmaking at a level of pencil and paper.

Keywords: convergent media, filmmaking, smartphone, Pakistan

Procedia PDF Downloads 261

Authors: Abdelkrim Alfalah, Lahcen Ouarbya, John Howroyd

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This paper investigates and compares the performance of four existing distances and similarity measures between partitions. The partition measures considered are Rand Index (RI), Adjusted Rand Index (ARI), Variation of Information (VI), and Normalised Variation of Information (NVI). This work investigates the ability of these partition measures to capture three predefined intuitions: the variation within randomly generated partitions, the sensitivity to small perturbations, and finally the independence from the dataset scale. It has been shown that the Adjusted Rand Index performed well overall, with regards to these three intuitions.

Keywords: clustering, comparing partitions, similarity measure, partition distance, partition metric, similarity between partitions, clustering comparison.

Procedia PDF Downloads 178

Authors: Malek Bendjaballah, Hacina Saidi, Sarra Hamidoud

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The aim of this study is to model and optimize the performance of a new electrocoagulation (E.C) process for the treatment of wastewater as well as the energy consumption in order to extrapolate it to the industrial scale. Through judicious application of an experimental design (DOE), it has been possible to evaluate the individual effects and interactions that have a significant influence on both objective functions (maximizing efficiency and minimizing energy consumption) by using aluminum electrodes as sacrificial anode. Preliminary experiments have shown that the pH of the medium, the applied potential and the treatment time with E.C are the main parameters. A factorial design 33 has been adopted to model performance and energy consumption. Under optimal conditions, the pollution reduction efficiency is 93%, combined with a minimum energy consumption of 2.60.10-3 kWh / mg-COD. The potential or current applied and the processing time and their interaction were the most influential parameters in the mathematical models obtained. The results of the modeling were also correlated with the experimental ones. The results offer promising opportunities to develop a clean process and inexpensive technology to eliminate or reduce wastewater,

Keywords: electrocoagulation, green process, experimental design, optimization

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Authors: Amrial, Yuri Oktaviani, Ziyan Muhammad Farhan

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On the phase of shifting paradigm into sustainability, Indonesia is involved in Sustainable Development Goals (SDGs) project. That act is revealed by creating Medium and Long Term Roadmap for Sustainable Finance in Indonesia which collaborated design by Indonesia Financial Service Board (OJK) and Ministry of Environment and Forestry. One of alternative for that infrastructure financing is sharia-based financing, Green Sukuk (Sukuk specified on sustainable infrastructure project). Green Sukuk for infrastructure financing in Indonesia can be issued by the government in the form of Sukuk Project Financing. Moreover, banks in Indonesia can also participate for the issuance of Green Sukuk. So that the banks can create a financing for people who are concerned about environmental issues. By using qualitative methods and literature review, this paper aims to discuss potential, strategy and planning of Green Sukuk for financing sustainable infrastructure in the purpose of SDGs. This paper will benefit for government to give scientific discussion on the strategy of Green Sukuk in promoting sustainable goals infrastructure project in Indonesia.

Keywords: green sukuk, infrastructure, SDGs, sustainable

Procedia PDF Downloads 347

Authors: Parvathy Anitha, Nilesh J. Vasa, M. S. Ramachandra Rao

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ZnO is a semiconducting material with a direct wide band gap of 3.37 eV and a large exciton binding energy of 60 meV at room temperature. Microspheres with high sphericity and symmetry exhibit unique functionalities which makes them excellent omnidirectional optical resonators. Hence there is an advent interest in fabrication of single crystalline semiconductor microspheres especially magnetic ZnO microspheres, as ZnO is a promising material for semiconductor device applications. Also, ZnO is non-toxic and biocompatible, implying it is a potential material for biomedical applications. Room temperature Photoluminescence (PL) spectra of the fabricated ZnO microspheres were measured, at an excitation wavelength of 325 nm. The ultraviolet (UV) luminescence observed is attributed to the room-temperature free exciton related near-band-edge (NBE) emission in ZnO. Besides the NBE luminescence, weak and broad visible luminescence (~560nm) was also observed. This broad emission band in the visible range is associated with oxygen vacancies related to structural defects. In transition metal (TM) ion-doped ZnO, 3d levels emissions of TM ions will modify the inherent characteristic emissions of ZnO. A micron-sized ZnO crystal has generally a wurtzite structure with a natural hexagonal cross section, which will serve as a WGM (whispering gallery mode) lasing micro cavity due to its high refractive index (~2.2). But hexagonal cavities suffers more optical loss at their corners in comparison to spherical structures; hence spheres may be a better candidate to achieve effective light confinement. In our study, highly smooth spherical shaped micro particles with different diameters ranging from ~4 to 6 μm were grown on different substrates. SEM (Scanning Electron Microscopy) and AFM (Atomic Force Microscopy) images show the presence of uniform smooth surfaced spheres. Raman scattering measurements from the fabricated samples at 488 nm light excitation provide convincing supports for the wurtzite structure of the prepared ZnO microspheres. WGM lasing studies from TM-doped ZnO microparticles are in progress.

Keywords: laser ablation, microcavity, photoluminescence, ZnO microsphere

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Authors: Celestine Mbakaan, Iorkyaa Ahemen, A. D. Onoja, A. N. Amah, Emmanuel Barki

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Rice husk (RH) is a natural sheath that forms and covers the grain of rice. The husk composed of hard materials, including opaline silica and lignin. It separates from its grain during rice milling. RH also contains approximately 15 to 28 wt % of silica in hydrated amorphous form. Nanosilica was derived from the husk of different rice varieties after pre-treating the husk (RH) with HCl and calcination at 550°C. Nanosilica derived from the husk of Osi rice variety produced the highest silica yield, and further pretreatment with 0.8 M H₃PO₄ acid removed more mineral impurities. The silica obtained from this rice variety was selected as a host matrix for doping with Sm³⁺ ions. Rice husk silica (RH-SiO₂) doped with samarium (RH-SiO₂: xSm³⁺ (x=0.01, 0.05, and 0.1 molar ratios) nanophosphors were synthesized via the sol-gel method. The structural analysis by X-ray diffraction analysis (XRD) reveals amorphous structure while the surface morphology, as revealed by SEM and TEM, indicates agglomerates of nano-sized spherical particles with an average particle size measuring 21 nm. The nanophosphor has a large surface area measuring 198.0 m²/g, and Fourier transform infrared spectroscopy (FT-IR) shows only a single absorption band which is strong and broad with a valley at 1063 cm⁻¹. Diffuse reflectance spectroscopy (DRS) shows strong absorptions at 319, 345, 362, 375, 401, and 474 nm, which can be exclusively assigned to the 6H5/2→4F11/2, 3H7/2, 4F9/2, 4D5/2, 4K11/2, and 4M15/2 + 4I11/2, transitions of Sm³⁺ respectively. The photoluminescence excitation spectra show that near UV and blue LEDs can effectively be used as excitation sources to produce red-orange and yellow-orange emission from Sm³⁺ ion-doped RH-SiO₂ nanophosphors. The photoluminescence (PL) of the nanophosphors gives three main lines; 568, 605, and 652 nm, which are attributed to the intra-4f shell transitions from the excited level to ground levels, respectively under excitation wavelengths of 365 and 400 nm. The result, as confirmed from the 1931 CIE coordinates diagram, indicates the emission of red-orange light by RH-SiO₂: xSm³⁺ (x=0.01 and 0.1 molar ratios) and yellow-orange light from RH-SiO₂: 0.05 Sm³⁺. Finally, the result shows that RH-SiO₂ doped with samarium (Sm³⁺) ions can be applicable in display applications.

Keywords: luminescence, nanosilica, nanophosphors, Sm³⁺

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Authors: Kazuo Nishimura, Junichi Hirata, Tadashi Yagi, Junko Urasaka

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This paper is an investigation of the effect of science education during the high school education how science graduates of universities are appreciated in the labor market in Japan. We conducted a survey utilizing the internet and analyzed the subjects they were good at and their annual income. The results confirm that among science graduates, workers adept at physics tend to have higher incomes compared to workers good at other subjects. Generational analysis based on the curriculum guideline amendments reveals that the generational difference is small among science majors who are good at physics.

Keywords: curriculum, income, physics, science

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Authors: Goksen Arik, Mihriban Korukluoglu

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Lactic acid bacteria (LAB) has been used commonly in the food industry. They can be used as natural preservatives because acidifying carried out in the medium can protect the last product against microbial spoilage. Besides, other metabolites produced by LAB during fermentation period have also an antimicrobial effect on pathogen and spoilage microorganisms in the food industry. LAB are responsible for the desirable and distinctive aroma and flavour which are observed in fermented food products such as pickle, kefir, yogurt, and cheese. Various LAB strains are able to produce B-group vitamins such as folate (B11), riboflavin (B2) and cobalamin (B12). Especially wild-type strains of LAB can produce B-group vitamins in high concentrations. These cultures may be used in food industry as a starter culture and also the microbial strains can be used in encapsulation technology for new and functional food product development. This review is based on the current applications of B-group vitamin producing LAB. Furthermore, the new technologies and innovative researches about B vitamin production in LAB have been demonstrated and discussed for determining their usage availability in various area in the food industry.

Keywords: B vitamin, food industry, lactic acid bacteria, starter culture, technology

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Authors: Kaushal Kishore, Vaibhav Jain, Hrishikesh Jugade, Saurabh Hadas, Manashi Adhikary, Goutam Mukhopadhyay, Sandip Bhattacharyya

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Rotary air compressors in air conditioners are used to suck excessive volume of air from the atmosphere in a small space to provide drive to the components attached to them. Hydraulic test is one of the most important methods to decide the suitability of these components for usage. In the present application, projection welding is used to join the hot rolled steel sheets after forming for manufacturing of air compressors. These sheets belong to two different high strength low alloy (HSLA) steel grades. It was observed that one batch of compressors made of a particular grade was cracking from the weld, whereas those made of another grade were passing the hydraulic tests. Cracking was repeatedly observed from the weld location. A detailed comparative study of the compressors which failed and successfully passed pressure tests has been presented. Location of crack initiation was identified to be the interface of fusion zone/heat affected zone. Shear dimples were observed on the fracture surface confirming the ductile mode of failure. Hardness profile across the weld revealed a sharp rise in hardness in the fusion zone. This was attributed to the presence of untempered martensitic lath in the fusion zone. A sharp metallurgical notch existed at the heat affected zone/fusion zone interface due to transition in microstructure from acicular ferrite and bainite in HAZ to untempered martensite in the fusion zone. In contrast, welds which did not fail during the pressure tests showed a smooth hardness profile with no abnormal rise in hardness in the fusion zone. The bainitic microstructure was observed in the fusion zone of successful welds. This difference in microstructural constituents in the fusion zone was attributed to the presence of a small amount of boron (0.002 wt. %) in the sheets which were cracking. Trace amount of boron is known to substantially increase the hardenability of HSLA steel, and cooling rate during resolidification in the fusion zone is sufficient to form martensite. Post-weld heat treatment was recommended to transform untempered martensite to tempered martensite with lower hardness.

Keywords: compressor, cracking, martensite, weld, boron, hardenability, high strength low alloy steel

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Authors: Xiao-Hua Zhu, Xin Yuan, Yi-Ran Zhao

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High-cadmium pollution in rice is a serious problem in many parts of China. Many kinds of remediation technologies have been tested and applied in many farmlands. Because of the productive function of the farmland, most technologies are inappropriate due to their destruction to the tillage soil layer. And the large labours and expensive fees of many technologies are also the restrictive factors for their applications. The conception of 'Root Micro-Geochemical Barrier' was proposed to reduce cadmium (Cd) bioavailability and the concentration of the cadmium in rice. Remediation and mitigation techniques were demonstrated on contaminated farmland in the downstream of some mine. According to the rule of rice growth, Cd would be absorbed by the crops in every growth stage, and the plant-absorb efficiency in the first stage of the tillering stage is almost the highest. We should create a method to protect the crops from heavy metal pollution, which could begin to work from the early growth stage. Many materials with repair property get our attention. The materials will create a barrier preventing Cd from being absorbed by the crops during all the growing process because the material has the ability to adsorb soil-Cd and making it losing its migration activity. And we should choose a good chance to put the materials into the crop-growing system cheaply as soon as early. Per plant, rice has a little root system scope, which makes the roots reach about 15cm deep and 15cm wide. So small root radiation area makes it possible for all the Cd approaching the roots to be adsorbed with a small amount of adsorbent. Mixing the remediation materials with the seed-raising soli and adding them to the tillage soil in the process of transplanting seedlings, we can control the soil-Cd activity in the range of roots to reduce the Cd-amount absorbed by the crops. Of course, the mineral materials must have enough adsorptive capacity and no additional pollution. More than 3000 square meters farmlands have been remediated. And on the application of root micro-geochemical barrier, the Cd-concentration in rice and the remediation-cost have been decreased by 90% and 80%, respectively, with little extra labour brought to the farmers. The Cd-concentrations in rice from remediated farmland have been controlled below 0.1 ppm. The remediation of one acre of contaminated cropland costs less than $100. The concept has its advantage in the remediation of paddy field contaminated by Cd, especially for the field with outside pollution sources.

Keywords: cadmium pollution, growth stage, cost, root micro-geochemistry barrier

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Authors: Faizan Ahmad, Jenna Wong

Abstract:

Time lag between peak values of horizontal and vertical seismic waves is a well-known phenomenon. Horizontal and vertical seismic waves, secondary and primary waves in nature respectively, travel through different layers of soil and the travel time is dependent upon the medium of wave transmission. In seismic analysis, many standardized codes do not require the actual vertical acceleration to be part of the analysis procedure. Instead, a factor load addition for a particular site is used to capture strength demands in case of vertical excitation. This study reviews the effects of vertical accelerations to analyze the behavior of a linearly rubber isolated structure in different time lag situations and frequency content by application of historical and simulated ground motions using SAP2000. The response of the structure is reviewed under multiple sets of ground motions and trends based on time lag and frequency variations are drawn. The accuracy of these results is discussed and evaluated to provide reasoning for use of real vertical excitations in seismic analysis procedures, especially for isolated structures.

Keywords: seismic analysis, vertical accelerations, time lag, isolated structures

Procedia PDF Downloads 320

Authors: S. Jamshidi, E. Feizi Ashtiani, M. Ardestani, A. Feizi Ashtiani

Abstract:

Waste load allocation (WLA) strategies usually intend to find economical policies for water resource management. Water quality trading (WQT) is an approach that uses discharge permit market to reduce total environmental protection costs. This primarily requires assigning discharge limits known as total maximum daily loads (TMDLs). These are determined by monitoring organizations with respect to the receiving water quality and remediation capabilities. The purpose of this study is to compare two approaches of TMDL assignment for WQT policy in small catchment area of Haraz River, in north of Iran. At first, TMDLs are assigned uniformly for the whole point sources to keep the concentrations of BOD and dissolved oxygen (DO) at the standard level at checkpoint (terminus point). This was simply simulated and controlled by Qual2kw software. In the second scenario, TMDLs are assigned using multi objective particle swarm optimization (MOPSO) method in which the environmental violation at river basin and total treatment costs are minimized simultaneously. In both scenarios, the equity index and the WLA based on trading discharge permits (TDP) are calculated. The comparative results showed that using economically optimized TMDLs (2nd scenario) has slightly more cost savings rather than uniform TMDL approach (1st scenario). The former annually costs about 1 M$ while the latter is 1.15 M$. WQT can decrease these annual costs to 0.9 and 1.1 M$, respectively. In other word, these approaches may save 35 and 45% economically in comparison with command and control policy. It means that using multi objective decision support systems (DSS) may find more economical WLA, however its outcome is not necessarily significant in comparison with uniform TMDLs. This may be due to the similar impact factors of dischargers in small catchments. Conversely, using uniform TMDLs for WQT brings more equity that makes stakeholders not feel that much envious of difference between TMDL and WQT allocation. In addition, for this case, determination of TMDLs uniformly would be much easier for monitoring. Consequently, uniform TMDL for TDP market is recommended as a sustainable approach. However, economical TMDLs can be used for larger watersheds.

Keywords: waste load allocation (WLA), water quality trading (WQT), total maximum daily loads (TMDLs), Haraz River, multi objective particle swarm optimization (MOPSO), equity

Procedia PDF Downloads 382

Authors: Yusuf, S. I., Saba, A., Olaoye, D. O., Ibrahim J. A., Yahaya H. M., Jatto A. O

Abstract:

Nuclear Magnetic Resonance (NMR) technology has been applied in several ways to provide vital information about petro-physical properties of reservoirs. However, due to the need to study the molecular behaviours of particles of the fluids in different restricted media, diffusion magnetic resonance equation is hereby applied in spherical coordinates and solved analytically using the method of separation of variables and solution of Legendre equation by Frobenius method. The viscous fluid considered in this research work is unused oil while the non-viscous fluid is water. The results obtained show that water begins to manifest appreciable change at radial adjustment value of 10 and Magnetization of 2.31191995400015x1014 and relaxes finally at 2.30x1014 at radial adjustment value of 1. On the other hand, unused engine oil begins to manifest its changes at radial adjustment value of 40 and Magnetization of 1.466557018x1014and relaxes finally at 1.48x1014 at radial adjustment value of 5.

Keywords: viscous and non-viscous fluid, restricted medium, relaxation times, coefficient of diffusion

Procedia PDF Downloads 66

Authors: K. Boonlertnirun, C. Rawdsiri, R. Suvannasara, S. Boonlertnirun

Abstract:

Thein corn variety well adapted to several planting conditions is usually accepted by most farmers. The objectives of this work were to evaluate yield potential of Thein corn inbred line grown in various nitrogen rates and plant conditions for selecting good inbred lines to be germ plasm for further breeding program. Split plot design with three replications was utilized as experimental design, three planting conditions: normal (control), low nitrogen, and high plant density condition, and sixteen inbred lines of Thein corn were used as main and subplot respectively. The results showed that no interaction between inbred line and planting condition in terms of yield. Correlation between planting conditions based on yield of inbred line was positive at medium level. Thein corn inbreds, namely L7, L5, L16, and L14 lines were tolerant to low nitrogen condition because they could produce high yield under all planting conditions and they were selected to be germ plasm for further breeding program.

Keywords: inbred line, planting condition, Thein corn, planting conditions

Procedia PDF Downloads 350

Authors: Viet-Hung Truong, Seung-Eock Kim

Abstract:

Rain–wind induced vibration of inclined cable is a special aerodynamic phenomenon because it is easily influenced by many factors, especially the distribution of rivulet and wind velocity. This paper proposes a new 3D model of inclined cable, based on single degree-of-freedom model. Aerodynamic forces are firstly established and verified with the existing results from a 2D model. The 3D model of inclined cable is developed. The 3D model is then applied to assess the effects of wind velocity distribution and the continuity of rivulets on the cable. Finally, an inclined cable model with small sag is investigated.

Keywords: 3D model, rain - wind induced vibration, rivulet, analytical model

Procedia PDF Downloads 475

Authors: Dimitra Alexiou

Abstract:

In an urban area the allocation placement of an emergency service mobile units, such as ambulances, police patrol must be designed so as to achieve a prompt response to demand locations. In this paper, a partition of a given urban network into distinct sub-networks is performed such that; the vertices in each component are close and simultaneously the difference of the sums of the corresponding population in the sub-networks is almost uniform. The objective here is to position appropriately in each sub-network a mobile emergency unit in order to reduce the response time to the demands. A mathematical model in the framework of graph theory is developed. In order to clarify the corresponding method a relevant numerical example is presented on a small network.

Keywords: graph partition, emergency service, distances, location

Procedia PDF Downloads 481