530 research outputs found

    Global Renewable Energy Indicators for Sustainable Development

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    Energy supplies from renewable sources are the essential components of every nation�s energy strategy because of their positive environmental impacts and sustainability. It is economically competitive with fossil fuels. It is one of the pillars of sustainable energy. Climate change, global warming that harms the environment, massive depletion of fossil fuels and hike in rate of oil has driven the governments to support renewable energy legislation and policies. The application and contribution of renewable energy are prominent for sustainable energy development. Renewable energy scenarios such as wind energy, solar energy, bio-energy, geothermal energy, hydro energy and hydrogen energy are presented in this paper. The upward trends of renewable energy installation give motivation and encouragement to enhance the efficiency of renewable energy systems

    Polyimides with pendent ethynyl groups

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    Several new polyimides containing pendent ethynyl groups were prepared and characterized. The new polyimides were prepared from the following novel ethynyl containing diamines; 1,1-bis(p aminophenyl)-1-(p ethynylphenyl) 2,2,2-trifluoroethane, and 1,1-bis(p aminophenyl)-1-(p phenylethynylphenyl)-2,2,2 trifluoroethane, and 1,1-bis(p aminophenyl)-1-(p hexynylphenyl)-2,2,2 trifluoroethane by reacting with either 3,3',4,4' benzophenone tetracarboxylic dianhydride or 2,2-bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6FDA). Inherent viscosities for the polymers ranged from 0.26 to 0.94 dL/g. Three copolymers prepared by reacting 10 mole pct. of one of the ethynyl containing diamines and 90 mole pct. of 2,2-bis-(4-(4 aminophenoxy)phenyl) hexafluoropropane with 6FDA were also prepared and characterized. Inherent viscosities for these copolymers ranged from 1.08 to 1.54 dL/g. Original polyimide glass transition temperatures were approx. 265 C while curing at 300 to 350 C for 1 hr in air increased the Tgs by approx. 10 C. Film properties and thermal stability were also measured for these copolyimides

    Assessment of Noise and Associated Health Impacts at Selected Secondary Schools in Ibadan, Nigeria

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    Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects. Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes. Results. Short-term, cross-sectional school-day noise levels ranged 68.3–84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems. Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources

    Influence of fluoride on the prevalence of diabetes mellitus in selected fluoride endemic areas of Tanzania

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    This research article published by International Journal of Biosciences, 2019Diabetes Mellitus prevalence in developing countries and globally is on the increase due to various factors and its association with excessive fluoride contamination is not much elucidated. This study aims to determine fluoride levels in serum along with capillary fasting blood sugar levels of individuals in selected area of Ngarenanyuki ward (fluoride endemic) in Arusha region, located at the slopes of volcanic mount Meru, which is connected to East African Great Rift Valley System. A cross sectional survey was conducted to assess fluoride levels in human sera (Measured by minitype Ion-Selective Electrode) and capillary fasting blood sugar levels (Measured by Automatic glucometer) in the community, after overnight fasting and to look for its relationship. The survey was conducted whereby, 50 individuals, aged 25 years old and above volunteered and consented for fluoride levels in serum determination along with capillary fasting blood sugar test. The 32 participants enrolled were females while18 were males. The mean age of the study participants was 48.7 (13.4) years. The median (range) fasting blood sugar was 4.8 (3.0 – 14.7) mmol/l and fluoride levels in serum was 0.0543 (0.0324 – 0.2200) mg/l. The correlation between the levels of fluoride in serum and fasting blood sugar was (Pearson`s correlation coefficient (r) = - 0.0632 and p < 0.663). There was no significant correlation between fluoride levels in serum and fasting blood sugar levels. The findings indicate that fluoride levels in serum does not influence the increase of fasting blood sugar levels. Further work to include other confounders is therefore recommended in order to understand broadly the influence of fluoride in hyperglycemia

    An exploratory study looking at the relationship marketing techniques used in the music festival industry

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    There are current issues and trends in the music festival market, which may affect the success of an event, and market saturation is at the forefront of these issues. Previous literature, maintaining the need for a marketing approach to festivals, identifi es the need for maintaining strong stakeholder relationships in order to succeed in a business environment; attention has been focused to the theory of relationship marketing (RM) because of the recognition that this practice is complementary to the marketing of festivals. The very nature of the music festival as an annual, usually, 4-day event means that effective marketing is needed to keep connections with the consumer throughout the year. This article focuses on the RM techniques utilised within the music festival industry from the viewpoint of the festival organiser in an attempt to establish how festival organisations value and monitor organisational relationships. This article explores the extent to which these relationships are valued and managed; furthermore, the variations between these intricate relationships are considered by focusing on those held with the organisation ’ s consumers and sponsors, the results of which have provided the ability to establish the importance and relevance of RM to the industry and further identify the marketing communication methods employed to establish and maintain such relationships. In-depth, convergent interviews have been conducted with a segment of music festival organisers from a range of events. The results have been integrated with the study of current literature to best exemplify these issues. It has been established that RM has a strong role in today ’ s commercial and independent music festival industry; technological advances are enabling the organiser to support online relationships further and increase consumer loyalty. There is a need to expand the research further because of the complexity of organisational relationships and the varying categories of festivals

    Asymmetric Synthesis and Biological Screening of Quinoxaline-Containing Synthetic Lipoxin A₄ Mimetics (QNX-sLXms)

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    Failure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing synthetic-LXA4-mimetics (QNX-sLXms). Eight novel compounds were screened for their impact on inflammatory responses. Structure–activity relationship (SAR) studies showed that (R)-6 (also referred to as AT-02-CT) was the most efficacious and potent anti-inflammatory compound of those tested. (R)-6 significantly attenuated lipopolysaccharide (LPS)- and tumor-necrosis-factor-α (TNF-α)-induced NF-κB activity in monocytes and vascular smooth muscle cells. The molecular target of (R)-6 was investigated. (R)-6 activated the endogenous LX receptor formyl peptide receptor 2 (ALX/FPR2). The anti-inflammatory properties of (R)-6 were further investigated in vivo in murine models of acute inflammation. Consistent with in vitro observations, (R)-6 attenuated inflammatory responses. These results support the therapeutic potential of the lead QNX-sLXm (R)-6 in the context of novel inflammatory regulators

    Asymmetric Synthesis and Biological Screening of Quinoxaline-Containing Synthetic Lipoxin A4 Mimetics (QNX-sLXms)

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    Failure to resolve inflammation underlies many prevalent pathologies. Recent insights have identified lipid mediators, typified by lipoxins (LXs), as drivers of inflammation resolution, suggesting potential therapeutic benefit. We report the asymmetric preparation of novel quinoxaline-containing syntheticLXA4-mimetics (QNX-sLXms). Eight novel compounds were screened for their impact on inflammatory responses. Structure− activity relationship (SAR) studies showed that (R)-6 (also referred to as AT-02-CT) was the most efficacious and potent anti-inflammatory compound of those tested. (R)-6 significantly attenuated lipopolysaccharide (LPS)- and tumor-necrosis-factor-α (TNF-α)-induced NF-κB activity in monocytes and vascular smooth muscle cells. The molecular target of (R)-6 was investigated. (R)-6 activated the endogenous LX receptor formyl peptide receptor 2 (ALX/FPR2). The anti-inflammatory properties of (R)-6 were further investigated in vivo in murine models of acute inflammation. Consistent with in vitro observations, (R)-6 attenuated inflammatory responses. These results support the therapeutic potential of the lead QNX-sLXm (R)-6 in the context of novel inflammatory regulators
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