Karakteristik Peredaman Getaran Konstruksi Model Jembatan untuk Pengembangan Sistem Diganosis Pola Gagal

In operation, the bridge structure is subjected to load variation both in the form of static load and dynamic load in variation of load intensity and frequency. In bridge structures made of steel structures, dynamic loading conditions can cause loosening of bolts, cracks and even structural failures. This paper describes the method of determining the damping bridge constant (c) by the logarithmic decrement calculation method of the vibration data generated by the impulse load. Furthermore the damping constant is used to calculate the vibration response equation of the structure along with the mass constant (m) and the stiffness of the structure (k). The mass constants are obtained by measurement whereas the stiffness constant of the structure is obtained by FEM modeling for open and closed structure models. The results of the analysis will be used to interpret the pattern of failed structures in the development of the diagnostic system. The calculation of damping constant for open and closed model is 0.07556 and 0.12513, while mass and stiffness constant for closed and open model model is 18 kg and 9 kg and 9523809.524 N / m and 183486.2 N / m for stiffness constant

A comprehensive assessment of MPPT algorithms to optimal power extraction of a PV panel

The electrical energy produced by photovoltaic (PV) process is inexhaustible, developable everywhere and clean. Whatever the conditions, it is desirable to extract the biggest amount of power from the solar panel. This is achieved with the use of a Maximum Power Point Tracking (MPPT) algorithm. Fluctuations in weather conditions (irradiation and temperature) strongly degrade the performance of the photovoltaic module's energy conversion and therefore all the power cannot be transferred to the load. The objective is to study and compare different approaches of MPPT algorithms to evaluate the power extracted under the standard test conditions and varying weather conditions. Results of the performance with all these algorithms are compared under different operating conditions. The results show that the Fuzzy Logic Controller (FLC) is the fastest in terms of stabilization and is followed respectively by Fractional Short-Circuit Current (FSCC), Fractional Open-Circuit Voltage (FOCV), Perturb and Observe (P&O), Incremental Conductance (INC) and Hill Climbing (HC) algorithms. The FLC also gives the best results in extracting, followed by P&O INC, HC, FSCC and FOCV algorithms

Evaluation of treatment response, drug resistance and HIV-1 variability among adolescents on first- And second-line antiretroviral therapy: A study protocol for a prospective observational study in the centre region of Cameroon (EDCTP READY-study)

BackgroundSub-Saharan Africa (SSA) alone has nine out of every 10 children living with HIV globally and monitoring in this setting remains suboptimal, even as these children grow older. With scalability of antiretroviral therapy (ART), several HIV-infected children are growing towards adolescence (over 2.1 million), with the potentials to reach adulthood. However, despite an overall reduction in HIV-related mortality, there are increasing deaths among adolescents living with HIV (ADLHIV), with limited evidence for improved policy-making. Of note, strategies for adolescent transition from pediatrics to adult-healthcare are critical to ensure successful treatment response and longer life expectancy. Interestingly, with uptakes in prevention of mother-to-child transmission, challenges in ART programs, and high viremia among children in SSA, the success rate of paediatric ART might be quickly jeopardised, with possible HIV-1 drug-resistance (HIVDR) emergence, especially after years of paediatric ART exposure. Therefore, monitoring ART response in adolescents and evaluating HIVDR patterns might limit disease progression and guide on subsequent ART options for SSA ADLHIV.ObjectivesAmong Cameroonian ADLHIV receiving ART, we shall evaluate the rate of immunovirologic failure, acquired HIVDR-associated mutations, HIV-1 subtype distribution, genetic variability in circulating (plasma) versus archived (cellular) viral strains, and HIVDR early warning indicators (EWIs) at different time-points.MethodsA prospective and observational study will be conducted among 250 ADLHIV (10-19years old) receiving ART in the centre region of Cameroon, and followed-up at 6 and 12months after enrollment. Following consecutive sampling at enrolment, plasma viral load and CD4/CD8 count will be measured, and genotypic resistance testing (GRT) will be performed both in plasma and in buffy coat for participants experiencing virological failure (two consecutive viremia >=1000 copies/ml). Plasma viral load and CD4/CD8 will be monitored for all participants at 6 and 12months after enrolment. HIVDR-EWIs will be monitored and survival analysis performed during the 12months follow-up. Primary outcomes are rates of virological failure, acquired-HIVDR, and mortality.DiscussionOur findings will provide evidence-based recommendations to ensure successful transition from paediatrics to adult ART regimens and highlight further needs of active ART combinations, for reduced morbidity and mortality in populations of ADLHIV within SSA

Entanglement and correlation in anisotropic quantum spin systems

Analytical expressions for the entanglement measures concurrence, i-concurrence and 3-tangle in terms of spin correlation functions are derived using general symmetries of the quantum spin system. These relations are exploited for the one-dimensional XXZ-model, in particular the concurrence and the critical temperature for disentanglement are calculated for finite systems with up to six qubits. A recent NMR quantum error correction experiment is analyzed within the framework of the proposed theoretical approach.Comment: 8 pages, 3 figure

Locating giant ground pangolins (Smutsia gigantea) using camera traps on burrows in the Dja Biosphere Reserve, Cameroon

Published online: 15 Jan 2018Giant ground pangolins (Smutsia gigantea) are poorly known and difficult to study due to their nocturnal and burrowing habits. Here, we test the efficacy of using camera traps on potentially active burrows identified by local Ba'Aka guides to rapidly locate giant ground pangolins in the wild for subsequent observation and tagging for telemetry studies. We deployed nine cameras on potential giant ground pangolin burrows in the Dja Biosphere Reserve, Cameroon. One camera photographed an adult male giant ground pangolin using a burrow within 2 days of camera deployment. The pangolin used the same burrow several times over a 25-day period and possible scent-marking behavior was recorded

Alarming rates of virological failure and HIV-1 drug resistance amongst adolescents living with perinatal HIV in both urban and rural settings: evidence from the EDCTP READY-study in Cameroon

Objectives: Adolescents living with perinatal HIV infection (ALPHI) experience persistently high mortality rates, particularly in resource-limited settings. It is therefore clinically important for us to understand the therapeutic response, acquired HIV drug resistance (HIVDR) and associated factors among ALPHI, according to geographical location. Methods: A study was conducted among consenting ALPHI in two urban and two rural health facilities in the Centre Region of Cameroon. World Health Organization (WHO) clinical staging, self-reported adherence, HIVDR early warning indicators (EWIs), immunological status (CD4 count) and plasma viral load (VL) were assessed. For those experiencing virological failure (VF, VL ≥ 1000 copies/mL), HIVDR testing was performed and interpreted using the Stanford HIV Drug Resistance Database v.8.9-1. Results: Of the 270 participants, most were on nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens (61.7% urban vs. 82.2% rural), and about one-third were poorly adherent (30.1% vs. 35.1%). Clinical failure rates (WHO-stage III/IV) in both settings were < 15%. In urban settings, the immunological failure (IF) rate (CD4  < 250 cells/μL) was 15.8%, statistically associated with late adolescence, female gender and poor adherence. The VF rate was 34.2%, statistically associated with poor adherence and NNRTI-based antiretroviral therapy. In the rural context, the IF rate was 26.9% and the VF rate was 52.7%, both statistically associated with advanced clinical stages. HIVDR rate was over 90% in both settings. EWIs were delayed drug pick-up, drug stock-outs and suboptimal viral suppression. Conclusions: Poor adherence, late adolescent age, female gender and advanced clinical staging worsen IF. The VF rate is high and consistent with the presence of HIVDR in both settings, driven by poor adherence, NNRTI-based regimen and advanced clinical staging