38 research outputs found
Photovoltaic Supplied T-Type Three- Phase Inverter with Harmonic Current Compensation Capability
In this paper, a T-Type grid-connected inverter with harmonic current compensation capability is proposed and studied for the on-grid photovoltaic (PV) systems. This idea is based on the modification of the existing photovoltaic inverter control algorithm with the adaptation of active power filter control algorithm. The grid-connected PV inverter has similar topology and control methods as that of the active power filter systems. However, such multifunctional inverters have not yet matured for commercial use and call for more research. In this work, a conventional phase locked-loop algorithm is used to determine the angular position of the synchronous reference of the grid voltages. PV power is estimated and fed into the control loop. Then, the measured currents at the load terminals are proceeded to obtain harmonic current components. The obtained control signals are used to drive the grid-connected T-Type inverter
К вопросу использования возобновляемых источников энергии в энергоэффективном строительстве
The paper presents dependences required for calculation of heat and energy for building operation within the period of its functioning and mean specific power of heat loss.Представлены зависимости для расчета теплоты и энергии на эксплуатацию здания в течение срока его функционирования и средней удельной мощности теплопотерь
Impact of Education and Network for Avian Influenza H5N1 in Human: Knowledge, Clinical Practice, and Motivation on Medical Providers in Vietnam
BACKGROUND: Knowledge, clinical practice, and professional motivation of medical providers relating to H5N1 infection have an important influence on care for H5N1 patients who require early diagnosis and early medical intervention. METHODS/PRINCIPAL FINDINGS: Novel educational programs including training and workshops for medical providers relating to H5N1 infection in Vietnam were originally created and implemented in 18 provincial hospitals in northern Vietnam between 2008 and 2010. A self-administered, structured questionnaire survey was conducted in 8 provincial hospitals where both educational training and workshops were previously provided. A total of 326 medical providers, including physicians, nurses, and laboratory technicians who attended or did not attend original programs were enrolled in the survey. Knowledge, clinical attitudes and practice (KAP), including motivation surrounding caring for H5N1 patients, were evaluated. The study indicated a high level of knowledge and motivation in all professional groups, with especially high levels in laboratory technicians. Conferences and educational programs were evaluated to be the main scientific information resources for physicians, along with information from colleagues. The chest radiographs and the initiation of antiviral treatment in the absence of RT-PCR result were identified as gaps in education. Factors possibly influencing professional motivation for caring for H5N1 patients included healthcare profession, the hospital where the respondents worked, age group, attendance at original educational programs and at educational programs which were conducted by international health-related organizations. CONCLUSIONS: Educational programs provide high knowledge and motivation for medical providers in Vietnam caring for H5N1 patients. Additional educational programs related to chest radiographs and an initiation of treatment in the absence of RT-PCR are needed. Networking is also necessary for sharing updated scientific information and practical experiences. These enhanced KAPs by educational programs and integrated systems among hospitals should result in appropriate care for H5N1 patients and may reduce morbidity and mortality
Polyphasic evaluation and cytotoxic investigation of isolated cyanobacteria with an emphasis on potent activities of a Scytonema strain
DATA AVAILABILITY STATEMENT : The datasets presented in this study can be found in
online repositories. The names of the repository/repositories
and accession number(s) can be found in the
article/supplementary material.Cyanobacteria are phototrophic organisms widely found in most types of
natural habitats in the tropical regions of the world. In this study, we isolated
and identified cyanobacterial strains from paddy soil in Hanoi (Vietnam)
and investigated their cytotoxic activities. Five isolated cyanobacterial strains
showed distinctive profiles of gene sequences (rRNA 16S and rbcL),
phylogenetic placements, and morphological characteristics. Based on the
polyphasic evaluation, they were classified as Scytonema bilaspurense NK13,
Hapalosiphon welwitschii MD2411, Aulosira sp. XN1103, Desikacharya sp.
NS2000, and Desmonostoc sp. NK1813. The cytotoxic screening revealed that
the extract of strain Scytonema bilaspurense NK13 exhibited potent cytotoxic
activities against four human cell lines of HeLa cells, OVCAR-8 cells, HaCaT
cells, and HEK-293T cells, with IC50 values of 3.8, 34.2, 21.6, and 0.6μg/mL,
respectively. This is the first time a well-classified Scytonema strain from
tropical habitat in Southeast Asia has been recognized as a potential producer
of cytotoxic compounds.The Vietnam National University, Hanoi (VNU).http://www.frontiersin.org/Microbiologyam2023BiochemistryGeneticsMicrobiology and Plant Patholog
In Vivo Ectopic Implantation Model to Assess Human Mesenchymal Progenitor Cell Potential
Clinical interest on human mesenchymal progenitor cells (hMPC) relies on their potential applicability in cell-based therapies. An in vitro characterization is usually performed in order to define MPC potency. However, in vitro predictions not always correlate with in vivo results and thus there is no consensus in how to really assess cell potency. Our goal was to provide an in vivo testing method to define cell behavior before therapeutic usage, especially for bone tissue engineering applications. In this context, we wondered whether bone marrow stromal cells (hBMSC) would proceed in an osteogenic microenvironment. Based on previous approaches, we developed a fibrin/ceramic/BMP-2/hBMSCs compound. We implanted the compound during only 2 weeks in NOD-SCID mice, either orthotopically to assess its osteoinductive property or subcutaneously to analyze its adequacy as a cell potency testing method. Using fluorescent cell labeling and immunohistochemistry techniques, we could ascertain cell differentiation to bone, bone marrow, cartilage, adipocyte and fibrous tissue. We observed differences in cell potential among different batches of hBMSCs, which did not strictly correlate with in vitro analyses. Our data indicate that the method we have developed is reliable, rapid and reproducible to define cell potency, and may be useful for testing cells destined to bone tissue engineering purposes. Additionally, results obtained with hMPCs from other sources indicate that our method is suitable for testing any potentially implantable mesenchymal cell. Finally, we propose that this model could successfully be employed for bone marrow niche and bone tumor studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12015-013-9464-1) contains supplementary material, which is available to authorized users
On Problem of Renewable Energy Source Usage in Energy Efficient Construction
The paper presents dependences required for calculation of heat and energy for building operation within the period of its functioning and mean specific power of heat loss
Determination temperature of a heat equation from the final value data
We introduce the truncation method for solving a backward heat conduction problem. For this method, we give the stability analysis with new error estimates. Meanwhile, we investigate the roles of regularization parameters in these two methods. These estimates prove that our method is effective