26 research outputs found

    Performance improvement potential of a PV/T integrated dual-source heat pump unit with a pressure booster ejector

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    Dual-source heat pump unit can utilize the evaporation of the refrigerant at two different pressures. By adopting an ejector, high-pressure refrigerant stream can be used to lift compressor inlet pressure which results in a higher coefficient of performance (COP). This study proposes a renewable energy sourced and high-efficiency heat pump system which can be easily building integrated to offer a renewable heating solution. The system is devised on the complementation of dual thermal sources; one is air and the other one is solar, to maximize the utilization of ambient energy for highly efficient operation of heat pump. Using the advantage of the relatively lower operating temperature in the solar collector line, the thermal efficiency of the collector would be sufficient in winter. Adaptation of photovoltaics in the collector as a PV/T unit, will benefit the system from the produced electricity for further reduction of the demand from the grid. Along with the use of PV/T collector, the system can be potentially carbon neutral for larger collector areas. In this study, the performance improvement potential of a dual-sourced heat pump unit with an ejector as a booster is investigated for different locations in Turkey which presents different solar and weather profiles. The optimum collector evaporation temperatures are determined, and COP improvement potentials are discussed for different conditions. For a heating supply of 5 kW, the COP of the system can be improved by 22.6% under 400 W/m2 and 10°C ambient using 15 m2 PV/T collector. Including the electricity generated from the PV, reduction of the electricity demand from the grid can reach to 75% for the same conditions

    Experimental Investigation of a MopFan-Based Photocatalytic Air Purification Device

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    Photocatalytic oxidation (PCO) is a potential approach for air cleaning, especially when utilising titanium dioxide (TiO2). A MopFan is similar to a roller brush but is made of flexible fibres coated with TiO2. Unlike conventional filter/mesh UV systems, a MopFan provides a wide UV-TiO2 interaction surface area and airflow passage. This revolutionary technique can be low cost, efficient, and potentially effective against viruses, making it suitable for cleaning indoor air. It is easy to use but technically advanced. The system may be mounted on walls, floors, or placed on desktops. A photocatalytic air purification based on MopFan prototype was designed, constructed and tested. This study utilised copper wires (0.1 mm, 0.3 mm, 0.4 mm, and 0.5 mm), plastic fibres (0.5 mm and 1.1 mm), brass wire (0.4 mm), steel wire (0.38 mm), and organic “coco” fibres (0.4 mm). Copper wire (0.5 mm) and organic fibre (0.4 mm) were found to be effective against SARS-CoV-2, but brass (0.4 mm) and plastic (0.5 mm) fibres were found only partially effective. The purification performance was compared using MopFan with plastic (0.5 mm), brass (0.4 mm) and organic “coco” (0.4 mm) fibres but the other materials were rejected due to their poor qualities or difficulties in manufacturing. It was found that the system has a better effectiveness with organic fibres, around 21% of reduction consistently throughout the test. It was also found that by using the photocatalytic MopFan air cleaning system, the final concentration of pollutants in a room is determined by the rate and concentration of pollutant generation. Highlights 1. Organic fibres do not require sanding prior to being coated with TiO2 solution. 2. Copper and organic fibres are effective SARS-CoV-2 inhibitors. 3. Organic fibres are the most efficient for air purification. 4. The performance of purification is related to the concentration of pollutants

    Delivery of an Ebola Virus-Positive Stillborn Infant in a Rural Community Health Center, Sierra Leone, 2015.

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    We report the case of an Ebola virus (EBOV) RNA-negative pregnant woman who delivered an EBOV RNA-positive stillborn infant at a community health center in rural Sierra Leone, 1 month after the mother's last possible exposure. The mother was later found to be immunoglobulins M and G positive indicating previous infection. The apparent absence of Ebola symptoms and not recognizing that the woman had previous contact with an Ebola patient led health workers performing the delivery to wear only minimal personal protection, potentially exposing them to a high risk of EBOV infection. This case emphasizes the importance of screening for epidemiological risk factors as well as classic and atypical symptoms of Ebola when caring for pregnant women, even once they have passed the typical time frame for exposure and incubation expected in nonpregnant adults. It also illustrates the need for health-care workers to use appropriate personal protection equipment when caring for pregnant women in an Ebola setting

    Contemporary practices of physical trainers in professional soccer: A qualitative study

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    Introduction: Physical trainers (PTs) are integral for managing load, reducing injury and optimizing performance in professional soccer. However, little is known about how this practitioners operate in the applied setting and how some of the nuances experienced influence practice. Methods: This study explored the contemporary practices of PTs in professional soccer. Semi-structured interviews were undertaken with eight PTs from different professional teams in European and South American leagues. Interview questions were designed to extract information on the evaluation of physical abilities, monitoring and control of training and injury prevention. Subsequently, the interviews were video-recorded, transcribed, translated and analyzed using a content analysis approach. Results: The results suggest that the evaluation of physical capacities is carried out by PTs at the beginning of the preseason. It also appears that it is attempted that this process of regular testing is applied during the competitive period, with most participants conducting partial physiological and physical evaluations at different stages throughout the competitive season. In relation to the monitoring and control of training, subjective feedback scales are used to estimate the internal load, and the use of GPS devices is common to quantify external loads. Injury prevention programmes were implemented by all participants and were generally in a multi-component format focused on preventing or optimizing physical capabilities. Discussion: These insights can be used as a scientific reference point to inform applied practice in professional soccer, especially for practitioners that are inexperienced and aspiring to enhance how they operate in the field. Future investigations should explore the practices of PTs in detail and across a wider network in order to gain deeper and comprehensive insights into the applied soccer environment

    Contemporary practices of physical trainers in professional soccer: A qualitative study

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    IntroductionPhysical trainers (PTs) are integral for managing load, reducing injury and optimizing performance in professional soccer. However, little is known about how this practitioners operate in the applied setting and how some of the nuances experienced influence practice.MethodsThis study explored the contemporary practices of PTs in professional soccer. Semi-structured interviews were undertaken with eight PTs from different professional teams in European and South American leagues. Interview questions were designed to extract information on the evaluation of physical abilities, monitoring and control of training and injury prevention. Subsequently, the interviews were video-recorded, transcribed, translated and analyzed using a content analysis approach.ResultsThe results suggest that the evaluation of physical capacities is carried out by PTs at the beginning of the preseason. It also appears that it is attempted that this process of regular testing is applied during the competitive period, with most participants conducting partial physiological and physical evaluations at different stages throughout the competitive season. In relation to the monitoring and control of training, subjective feedback scales are used to estimate the internal load, and the use of GPS devices is common to quantify external loads. Injury prevention programmes were implemented by all participants and were generally in a multi-component format focused on preventing or optimizing physical capabilities.DiscussionThese insights can be used as a scientific reference point to inform applied practice in professional soccer, especially for practitioners that are inexperienced and aspiring to enhance how they operate in the field. Future investigations should explore the practices of PTs in detail and across a wider network in order to gain deeper and comprehensive insights into the applied soccer environment

    Clinical Illness and Outcomes in Patients with Ebola in Sierra Leone

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    Background Limited clinical and laboratory data are available on patients with Ebola virus disease (EVD). The Kenema Government Hospital in Sierra Leone, which had an existing infrastructure for research regarding viral hemorrhagic fever, has received and cared for patients with EVD since the beginning of the outbreak in Sierra Leone in May 2014. Methods We reviewed available epidemiologic, clinical, and laboratory records of patients in whom EVD was diagnosed between May 25 and June 18, 2014. We used quantitative reverse-transcriptase–polymerase-chain-reaction assays to assess the load of Ebola virus (EBOV, Zaire species) in a subgroup of patients. Results Of 106 patients in whom EVD was diagnosed, 87 had a known outcome, and 44 had detailed clinical information available. The incubation period was estimated to be 6 to 12 days, and the case fatality rate was 74%. Common findings at presentation included fever (in 89% of the patients), headache (in 80%), weakness (in 66%), dizziness (in 60%), diarrhea (in 51%), abdominal pain (in 40%), and vomiting (in 34%). Clinical and laboratory factors at presentation that were associated with a fatal outcome included fever, weakness, dizziness, diarrhea, and elevated levels of blood urea nitrogen, aspartate aminotransferase, and creatinine. Exploratory analyses indicated that patients under the age of 21 years had a lower case fatality rate than those over the age of 45 years (57% vs. 94%, P=0.03), and patients presenting with fewer than 100,000 EBOV copies per milliliter had a lower case fatality rate than those with 10 million EBOV copies per milliliter or more (33% vs. 94%, P=0.003). Bleeding occurred in only 1 patient. Conclusions The incubation period and case fatality rate among patients with EVD in Sierra Leone are similar to those observed elsewhere in the 2014 outbreak and in previous outbreaks. Although bleeding was an infrequent finding, diarrhea and other gastrointestinal manifestations were common. (Funded by the National Institutes of Health and others.

    Import Substitution Industrialization [ISI]: An approach to Global Economic Sustainability

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    Globalisation has over the years brought about openness, thus creating an inextricable link among countries through various channels, including trade and investment. Consequently, there has been a substantial expansion in trade in goods and services and the flow of foreign direct investment between developed and developing countries. Even though, both have benefitted from this global openness, the balance of benefits is mainly tilted to developed countries, reinforced by the fact that developing countries have been importing more and exporting less to these countries – a reflection of the under-developed state of their industrial sector, which is evident in their export of mainly unrefined or primary products, with little or no value addition taking place. This gives attestation to the presence of an insignificant import substitution-oriented manufacturing activity in such countries, which have rendered them heavily reliant on imports for their survival – by extension making them highly susceptible to external risks and shocks. This brought about the inception of ISI, which originated from as early as in the 1930s through into the 1960s in Latin America and some parts of Asia and Africa – a notion that was meant to incorporate three stages, namely ‘domestic production of previously imported non-durable consumer goods, extension of production to a wide-range of consumer durables and complex manufactured items and finally, exporting of manufactured goods, with the vision of diversifying to multiple range of items’ (Bussell,, n/d)

    Fostering Sustainable Innovation through Creative Destruction Theory

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    The current information age is modelled on the advancement of innovative mindset of creative thinkers, championed through means associated with transformative technologies embodied on events like, high speed internet and payment system, thereby making it possible for transactions to be dealt with almost instantaneously. Such developments are essentially vital, given its prospect for championing growth rate and dynamism in the world economy and also, the need to ensure living conditions are adequately satisfied, particularly in the direction of the Sustainable Development Goals (SDG) earmarked for full implementation in the year 2030. The concept of innovation is widely used in all walks of life - the effort of Schumpeter’s paradoxical term, “creative destruction” became highly prominent in the 1950s, which many economists in recent time have endeavoured to linked with free market economics (Cozzi and Galli, 2019; Benigno and Fornaro, 2018). Creative destruction as proposed by Schumpeter, and also explained by Alm and Cox (Online) is essentially facts about capitalism, which is thought to be a shorthand description of free market’s messy way of delivering progress

    Economics of Technology Innovation for Sustainable Growth – With reference to Sub-Saharan Africa (SSA)

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    Innovation economics is geared towards harnessing the good in human ingenuity to bring about dynamic efficiency that result in changed habit formation of consumer choices in the market, together with high quality / performance of goods and services consumed by economic agents. In as much as the worries or concern that innovation bring, given its characteristics of creatively destroying existing ideas or product existence in the market, it can still be seen as the way forward in accumulating wealth creation, while increasing welfare opportunities for those who are ready to embrace change in a fiercely competitive environment. Figure 1 below provide a simple illustration of how cost-reducing innovation and technological change can be utilised to bring about positive gains in producer and consumer surplus (Riley, Online) which eventually result in lower prices, and the scope for an increase in real income of households or individuals
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