168 research outputs found

    Environmental management systems in construction projects in Kenya: barriers, drivers, adoption levels

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    The construction industry is established to be responsible for one third of Green House Gas (GHG) emissions and has an oversized carbon footprint which is attributed to the industry’s large materials’ appetite. The industry is heavily reliant on natural resource utilisation and is reported to contribute over 33% of waste materials in the landfills. Kenya seems to be fighting a losing battle with poor management of natural resources, waste management, inter alia environmental impacts associated with; the extraction, transport, processing, fabrication, installation and disposal of the building industry materials.Waste management and handling of hazardous material is a menace to rapidly developing nations. To keep economic progress in its path, sustainable resource use and responsible waste management is needful. Action needs to be stirred in the construction sector as the major polluter. Sound and practical management of environmental matters cannot be decoupled from enterprise risk management. Therefore, corporate governance in construction firms needs to adopt responsible resource consumption and production for overall sustainable growth and development.In an effort to understand and address this problem at source, this study evaluated the level of fusion of business and environmental goals in the construction sector in Kenya. It critically examines at project level, Environmental Management Systems (EMS) employed by established and new entrant construction firms, with a focus on waste management, hazardous material (HazMat) waste handling, barriers and drivers of environmental performance as well as level of inclusion of environmental aspects in product design in the construction firms in Kenya.The paper further, proposes solid ways to broaden and enhance the quality of environmentally conscious infrastructure in developing nations like Kenya.Keywords: construction, demolition, waste, policy, sustainability, barriers and driver

    Retail Market Prices of Fonio Reveal The Demand For Quality Characteristics in Bamako, Mali

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    African consumers' expectations concerning the quality of food products are great. In spite of constrained budgets, we showed that market retail prices revealed quality preferences of the consumers and not just production costs. In very poor countries like Mali, food innovation is limited by the very low purchasing power of the population. However, technological food product or process innovations are possible and sometimes valuable. Demand driven innovation may lead to open new markets, opportunities for small and medium scale enterprises and to improve consumers' welfare. Based on this assumption, technical research was done to provide new food products. In this paper, we used both sensory tests and a hedonic price approach, to estimate the consumers' demand for different characteristics of fonio, a West African cereal, and showed that poor consumers have quality requirements and pay for them. We showed that the shadow price or hedonic price paid for quality characteristics is small but significant. A comparison between sensory tests and a market study showed a convergence between what people say they prefer and what they really pay for. Results were consistent and showed directions for technological improvement of the product and its production process. The partial least square method was used to estimate hedonic prices of the different modalities of fonio quality traits. This method was interesting since it solved the ordinary least square method's colinearity problems. ...French Abstract : Les attentes des consommateurs africains concernant la qualitĂ© de l'alimentation sont importantes malgrĂ© des budgets trĂšs contraints. Nous montrons ici que les prix de marchĂ©s rĂ©vĂšlent des prĂ©fĂ©rences qualitatives et non seulement des coĂ»ts de production. Dans des pays trĂšs pauvres comme le Mali, l'innovation technologique est limitĂ©e par le trĂšs faible pouvoir d'achat de la population. Cependant les innovations technologiques sont possibles et parfois payantes. L'innovation en rĂ©ponse Ă  une demande peut permettre d'ouvrir de nouveaux marchĂ©s, de donner des opportunitĂ©s aux petites et moyennes entreprises et d'amĂ©liorer le bien-ĂȘtre des consommateurs. Sur la base de cette hypothĂšse, la recherche technologique s'applique Ă  fournir de nouveaux produits. Dans cet article, en utilisant Ă  la fois des tests de dĂ©gustation et une analyse des prix hĂ©doniques, nous estimons la demande des consommateurs pour diffĂ©rentes caractĂ©ristiques du fonio, une cĂ©rĂ©ale d'Afrique de l'Ouest. Nous montrons que des consommateurs pauvres ont des exigences de qualitĂ© et paient de fait pour les satisfaire. Nous montrons que les prix hĂ©doniques ou shadow prices payĂ©s pour les caractĂ©ristiques qualitatives sont faibles mais significatifs. La comparaison des tests sensoriels et de l'Ă©tude de marchĂ© montre une convergence entre ce que les gens disent et ce pour quoi ils paient rĂ©ellement. Les rĂ©sultats sont cohĂ©rents et montrent des directions pour l'amĂ©lioration technologique des produits et des procĂ©dĂ©s de transformation. La mĂ©thode des moindres carrĂ©s ordinaires a Ă©tĂ© utilisĂ©e pour l'estimation des prix hĂ©doniques des diffĂ©rentes modalitĂ©s des attributs de qualitĂ© du fonio. Cette mĂ©thode est intĂ©ressante car elle rĂ©sout les problĂšmes de colinĂ©aritĂ©.FONIO; CEREAL; QUALITY; HEDONIC PRICES; PLS METHOD; EMPIRICAL INVESTIGATION

    Grounding of Human Environments and Activities for Autonomous Robots

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    With the recent proliferation of robotic applications in domestic and industrial scenarios, it is vital for robots to continually learn about their environments and about the humans they share their environments with. In this paper, we present a framework for autonomous, unsupervised learning from various sensory sources of useful human ‘concepts’; including colours, people names, usable objects and simple activities. This is achieved by integrating state-of-the-art object segmentation, pose estimation, activity analysis and language grounding into a continual learning framework. Learned concepts are grounded to natural language if commentary is available, allowing the robot to communicate in a human-understandable way. We show, using a challenging, real-world dataset of human activities, that our framework is able to extract useful concepts, ground natural language descriptions to them, and, as a proof-of-concept, to generate simple sentences from templates to describe people and activities

    Ecologically friendly corrosion inhibitor for low alloy steels and aluminium alloys

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    The corrosion protective properties of environmentally friendly Ce-citrate were analyzed on AISI 4130 low alloy carbon steel and AA7075 aluminum alloy in 0.05 M NaCl solution. For this purpose different concentrations of corrosion inhibitor were analyzed in the range of 0.1-0.5 mM. Electrochemical impedance spectroscopy and potentiodynamic polarization test were used for measurements of resistance to general corrosion. Pitting potential Epit value was used for the determination of resistance to pitting corrosion. Additionally, corrosion resistance measurements and determination of pitting potential value were performed in Ce-chloride solution with the aim of comparation. SEM microscopy was used for the determination of changes on the surface of the specimens after corrosion testing. The XPS method was used for the analyses of the formed inhibitory layer on the steel specimen surface. It has been shown that significant amounts of cerium, as well as the citrate anions, are present in the inhibitory layer. Ce-citrates have proved to be an effective corrosion inhibitor for AISI 4130 steel as well as an effective pitting corrosion inhibitor for AA7075 aluminum alloy. The mechanism of action of Ce-citrate on AISI 4130 steel and AA7075 aluminum alloy has been proposed.XXIII YUCORR International Conference, 116th-19th May 2022, Divčibare, Serbia, invited talk (Bojana Radojković

    Semiconductor-cavity QED in high-Q regimes: Detuning effect

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    The non-resonant interaction between the high-density excitons in a quantum well and a single mode cavity field is investigated. An analytical expression for the physical spectrum of the excitons is obtained. The spectral properties of the excitons, which are initially prepared in the number states or the superposed states of the two different number states by the resonant femtosecond pulse pumping experiment, are studied. Numerical study of the physical spectrum is carried out and a discussion of the detuning effect is presented.Comment: 7 pages, 8 figure

    Tailored climate projections to assess site-specific vulnerability of tea production

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    Tailored climate change information is essential to understand future climate risks and identify relevant adaptation strategies. However, distilling and effectively communicating decision-relevant information from climate science remains challenging. In this paper, we develop and apply an iterative stakeholder engagement approach and a Site Specific Synthesis of Projected Range (SPR), to co-produce future climate information for Africa’s largest tea producing nations - Kenya and Malawi - for the mid-and late-21st century. SPR provides a novel analysis approach, which combines long-term station observations with projections from 29 global climate models and the first convection-permitting high-resolution climate projection for Africa (CP4A). This addresses the mismatch between spatial scales of projections, large-scale modelling uncertainties and stakeholder need for site-specific information. Iterative stakeholder engagement and communication helped to build trust, allowed use of new observation data and improved visualisations of climate information for stakeholders. SPR demonstrates site-specificity in changes in all metrics, showing risks of large changes in tea crop sensitive metrics. All nine locations analysed show substantial (up to four times) increases in heatwave days and large decreases in cold nights by 2050s compared to the current climate. While tea producers are already witnessing changing climatic conditions, potential future changes will greatly affect the resilience of tea production, thereby affecting the sustainability and quality of tea production in the region. Site specific climate information iteratively co-produced with stakeholders helps them to identify location-specific adaptation strategies and investment priorities, potentially safeguarding supply-chains and millions of livelihoods

    Cysteine and modified cysteine as green inhibitors of aluminum alloy corrosion

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    In its pure form, aluminum is easy to process and has a high level of corrosion resistance. However, due to its low strength the possibility of application of pure aluminum is reduced. When alloyed, aluminum alloys are widely used material in construction, different industries, airspace and military. Commercial 7000 series aluminum alloys have zinc as the main alloying element, followed by magnesium. This 7000 aluminum series offers a very high strength when heat-treated, which comes from its composition. The life time of these alloys is reduced due to corrosion damage. It is known that corrosion directly or indirectly affects materials, human health and safety, and it causes global economic and environmental problem. The use of inhibitors in corrosion protection is the simplest, most economical and most efficient approach that is routinely used to ‘reduce’ this problem in industry. The most widely used inorganic inhibitors, such as chromates, are not safe, causing health and safety problems due to their toxicity. Organic compounds have increased interest of the scientific community as potential inhibitors in exchange for the most commonly used. The aim of this study was to investigate new green, eco-friendly inhibitors from the group of amino acid and their combination with lanthanides. For the purposes of this investigation, cerium-cysteine complex was synthesized and analyzed by Fourier-Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM / EDS), Potentiostatic Electrochemical Impedance Spectroscopy (PEIS) and Linear Sweep Voltammetry (LSV) analyses. SEM/EDS was used for morphological analysis and to determine the composition of the aluminum alloy on which the electrochemical tests have been performed. Electrochemical measurements (PEIS, LSV) were erformed in order to test the inhibitory efficacy in 0.1M NaCl at room temperature. Different concentrations of cysteine and Ce-cysteine complex were examined to optimize the process. The adsorption of the inhibitor follows the Langmuir isotherm, and based on the electrochemical results and calculated thermodynamic potential (Gibbs free energy) it can be concluded that both cysteine and cerium-cysteine complex are mixed type of inhibitors. It can be concluded that both cysteine and Ce-cysteine complex inhibitors satisfactory inhibition effect on aluminum alloy corrosion

    Zeleni inhibitori korozije sa cisteinom i kompleksom cerijum-cisteina na 7000 seriji aluminijumske legure

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    The aim of this study was to investigate environmentally-friendly corrosion inhibitors based on the cerium-cysteine and their effect on 7xxx series aluminum alloy. The cysteine and cerium-cysteine complex structures were analyzed by Fourier-Transform Infrared spectroscopy (FTIR). The structure of cerium-cysteine was additionally determined using Nuclear Magnetic Resonance (NMR) and Elemental Analysis. Inhibitors efficiency was analyzed with Electrochemical Impedance Spectroscopy (EIS) and Potentiodynamic polarization techniques in 0.1M NaCl at room temperature, while Scanning Electron Microscopy analyzed the surface appearance and microstructure of the tested aluminum alloy with Energy Dispersive Spectroscopy (SEM / EDS) and Optical Microscope (OM). Different amounts of cysteine were examined in order to find an optimal concentration of inhibitor. The adsorption of the inhibitors followed the Langmuir isotherm, and based on the EIS results and calculated thermodynamic potential (Gibbs free energy), cysteine and cerium-cysteine proved to be good inhibitors for tested aluminum alloy. The optimal cysteine concentration of 0.06 mM as a corrosion inhibitor of 7xxx series aluminum alloy was determined. EIS diagrams confirmed that cysteine showed better inhibition than Ce-Cys complex

    The UK clinical aptitude test and clinical course performance at Nottingham: a prospective cohort study

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    Background The UK Clinical Aptitude Test (UKCAT) was introduced in 2006 as an additional tool for the selection of medical students. It tests mental ability in four distinct domains (Verbal Reasoning, Quantitative Reasoning, Abstract Reasoning, and Decision Analysis), and the results are available to students and admission panels in advance of the selection process. Our first study showed little evidence of any predictive validity for performance in the first two years of the Nottingham undergraduate course. The study objective was to determine whether the UKCAT scores had any predictive value for the later parts of the course, largely delivered via clinical placements. Methods Students entering the course in 2007 and who had taken the UKCAT were asked for permission to use their anonymised data in research. The UKCAT scores were incorporated into a database with routine pre-admission socio-demographics and subsequent course performance data. Correlation analysis was followed by hierarchical multivariate linear regression. Results The original study group comprised 204/254 (80%) of the full entry cohort. With attrition over the five years of the course this fell to 185 (73%) by Year 5. The Verbal Reasoning score and the UKCAT Total score both demonstrated some univariate correlations with clinical knowledge marks, and slightly less with clinical skills. No parts of the UKCAT proved to be an independent predictor of clinical course marks, whereas prior attainment was a highly significant predictor (p <0.001). Conclusions This study of one cohort of Nottingham medical students showed that UKCAT scores at admission did not independently predict subsequent performance on the course. Whilst the test adds another dimension to the selection process, its fairness and validity in selecting promising students remains unproven, and requires wider investigation and debate by other schools
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