275 research outputs found

    Comments

    Get PDF

    Success Factors in Mega Infrastructure Projects (MIPs): Developing Nations Perspectives

    Get PDF
    There is a common understanding that megaprojects are important drivers of societal change. Their impact is an important phenomenon because of the influence on both society and economy. Despite the best practices all around the globe, numerous challenges can move a megaproject from a programmed success to a failure scenario. It can create an uncertainty over the result, impact as well as over the justification of the enormous amount of resources spent. Despite much research done so far, it is still not clear what are the causes of megaproject success. However, there seems to be no clear understanding as to what are the major success factors on which a project is judged in developing nation. Hence, this study aims to analyse the most vital success factors that would label a megaproject as being a complete accomplishment. The research was conducted using quantitative survey. The questionnaires were distributed to different stakeholders who have participated in previous megaproject. The questions were based on a Likert's scale rating and analysed using relative important index (RII). The result from the analysis was then used in establishing the main success factors in mega project whilst focusing on what is regarded as the most important success factors as projects are unique with certain needs. The key finding from the study is the Project Managers experience and co existence with other stakeholders which was found as vital factor for the successful delivery of MIPs. Therefore, the research demonstrates the implication of the role of the project managers in terms of coordination of other parties in achieving stakeholders goal

    Characteristic Study of Solar Photovoltaic Array under Different Partial Shading Conditions

    Get PDF
    © The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Photovoltaic (PV) systems are frequently exposed to partial or complete shading phenomena. Partial shading has a profound impact on the performance of solar power generation. The operational performance of PV arrays under partial shading shows multiple maximum power point peaks, therefore it is challenging to identify the actual maximum power point. This paper investigates the impact of partial shading location on the output power of solar photovoltaic arrays with various configurations. Multiple photovoltaic strings, in both parallel and series configurations, are considered. Different random shading patterns are considered and analyzed to determine which configuration has higher maximum power point. The sensitivity of the partial shading can change according to the partial shading types, shading pattern, and the configuration used to connect all PV modules. Moreover, the study also investigates the output of the PV array with shading two random models, two consecutive models, and three random and consecutive modules. Experimental results validate the analysis and demonstrate the effect of various partial shading on the eficiency and performance of the PV system.Peer reviewe

    Laboratory Measurement of the Temperature Dependence of Gaseous Sulfur Dioxide (SO2) Microwave Absorption with Application to the Venus Atmosphere

    Get PDF
    High-accuracy laboratory measurements of the temperature dependence of the opacity from gaseous sulfur dioxide (SO2) in a carbon dioxide (CO2) atmosphere at temperatures from 290 to 505 K and at pressures from 1 to 4 atm have been conducted at frequencies of 2.25 GHz (13.3 cm), 8.5 GHz (3.5 cm), and 21.7 GHz (1.4 cm). Based on these absorptivity measurements, a Ben-Reuven (BR) line shape model has been developed that provides a more accurate characterization of the microwave absorption of gaseous S02 in the Venus atmosphere as compared with other formalisms. The developed BR formalism is incorporated into a radiative transfer model. The resulting microwave emission spectrum of Venus is then used to set an upper limit on the disk-averaged abundance of gaseous S02 below the main cloud layer. It is found that gaseous S02 has an upper limit of 150 ppm, which compares well with previous spacecraft in situ measurements and Earth-based radio astronomical observations

    Fractional Effective Quark-Antiquark Interaction in Symplectic Quantum Mechanics

    Full text link
    We investigate within the formalism of Symplectic Quantum Mechanics a two-dimensional non-relativistic strong interacting system that represents the bound heavy quark-antiquark state, where it was considered a linear potential in the context of generalized fractional derivatives. For this purpose, it was solved the Schr\"odinger equation in phase space with the linear potential. The solution (ground state) is obtained, analyzed through the Wigner function comparing with the original solution, the Airy function for the meson cc‾c\overline{c}. The identified eigenfunctions are connected to the Wigner function via the Weyl product and the Galilei group representation theory in phase space. In some ways, compared to the wave function, the Wigner function makes it simpler to see how the meson system is non-classical.Comment: 7 pages, 2 figure

    Evaluation of programmes in the field of care and prevention of HIV.

    Get PDF
    Treball Final de Grau en Psicologia. Codi: PS1048. Curs: 2017/2018The objective of this work was to evaluate a preventive program taught by CASDA with the aim of educating about health, sexuality, SIDA and VIH . Through the consultation of scientific articles, similar programs of other autonomous communities and interviews with the coordinator of CASDA, we have carried out a program evaluatio

    On the Fractional Quark-Antiquark Confinement and Symplectic Quantum Mechanics

    Full text link
    Using the formalism of generalized fractional derivatives, a two-dimensional non-relativistic meson system is studied. The mesons are interacting by a Cornell potential. The system is formulated in the domain of the symplectic quantum mechanics by means of the generalized fractional Nikiforov-Uvarov method. The corresponding Wigner function and the energy eigenvalues are then derived. The effect of fractional parameters α\alpha and β\beta with the ground state solution is analyzed through the Wigner function for the charm-anticharm, bottom-antibottom and bc‾b\overline{c} mesons. One of the fundamental achievements of such Cornell model is the determination of heavy quarkonia mass spectra. We have computed these masses and theComment: 11 pages, 3 figure

    Anti-Annexin V Antibodies: Association with Vascular Involvement and Disease Outcome in Patients with Systemic Sclerosis

    Get PDF
    Background: Systemic Sclerosis (SSc) is characterized by skin thickening, fibrosis and vascular obliteration. The onset and course are heterogeneous. Prominent features include autoimmunity, inflammation and vascular damage. Aim of study: To measure the level of serum Anti-Annexin V antibodies in SSc patients and to study its significance in relation to vascular damage in these patients. Patients and methods: Twenty patients with SSc (12 with diffuse SSc and 8 with the limited form) and 10 healthy age and sex matched volunteers as controls were all subjected to routine laboratory testing and immunological profiling including antinuclear, anti-Scl-70, anticentomere, anticardiolipin antibodies and anti-annexin V antibodies titres. Vascular damage was assessed by clinical examination and assessment of the disease activity score, nailfold capillaroscopy and colour flow Doppler of the renal arteries; Doppler echocardiography was used for assessing pulmonary hypertension. Results: Anti-annexin V antibodies were detected in 75% of patients. Comparisons between anti-annexin V in diffuse and limited subgroups showed no significance; however a statistically significant positive correlation was found between Anti-annexin V titre and the degree of vascular damage in SSc patients. Anti-annexin V increased significantly in patients with severe vascular damage in comparison with those less affected (15.3 ± 6.6 vs. 11.25 ± 3.6, P , 0.05). A significant positive correlation was found between Anti-annexin V titre and both the ACL titre (r = 0.79, P , 0.001) and the resistive index of the main renal artery (r = 0.42, P , 0.05). Conclusion: Anti-annexin V antibodies were significantly present in sera of patients with SSc. Patients with more severe forms of vascular damage had higher titres of these antibodies. Anti-annexin V antibodies are a sensitive predictor of vascular damage in SSc and could serve as a useful parameter in discriminating patients with a higher risk of vascular affection from those without

    Impact of resonance decays on critical point signals in net-proton fluctuations

    Full text link
    The non-monotonic beam energy dependence of the higher cumulants of net-proton fluctuations is a widely studied signature of the conjectured presence of a critical point in the QCD phase diagram. In this work we study the effect of resonance decays on critical fluctuations. We show that resonance effects reduce the signatures of critical fluctuations, but that for reasonable parameter choices critical effects in the net-proton cumulants survive. The relative role of resonance decays has a weak dependence on the order of the cumulants studied with a slightly stronger suppression of critical effects for higher-order cumulants

    Identification of a humanized mouse model for functional testing of immune-mediated biomaterial foreign body response.

    Get PDF
    Biomedical devices comprise a major component of modern medicine, however immune-mediated fibrosis and rejection can limit their function over time. Here, we describe a humanized mouse model that recapitulates fibrosis following biomaterial implantation. Cellular and cytokine responses to multiple biomaterials were evaluated across different implant sites. Human innate immune macrophages were verified as essential to biomaterial rejection in this model and were capable of cross-talk with mouse fibroblasts for collagen matrix deposition. Cytokine and cytokine receptor array analysis confirmed core signaling in the fibrotic cascade. Foreign body giant cell formation, often unobserved in mice, was also prominent. Last, high-resolution microscopy coupled with multiplexed antibody capture digital profiling analysis supplied spatial resolution of rejection responses. This model enables the study of human immune cell-mediated fibrosis and interactions with implanted biomaterials and devices
    • …
    corecore