346 research outputs found

    Biosynthesis and characterization of polyhydroxyalkanoate containing high 3-hydroxyhexanoate monomer fraction from crude palm kernel oil by recombinant Cupriavidus necator

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    The potential of plant oils as sole carbon sources for production of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction using the recombinant Cupriavidus necator strain Re2160/pCB113 has been investigated. Various types and concentrations of plant oils were evaluated for efficient conversion of P(3HB-co-3HHx) copolymer. Crude palm kernel oil (CPKO) at a concentration of 2.5 g/L was found to be most suitable for production of copolymer with a 3HHx content of approximately 70 mol%. The time profile of these cells was also examined in order to study the trend of 3HHx monomer incorporation, PHA production and PHA synthase activity. [superscript 1]H NMR and [superscript 13]C NMR analyses confirmed the presence of P(3HB-co-3HHx) copolymer containing a high 3HHx monomer fraction, in which monomers were not randomly distributed. The results of various characterization analyses revealed that the copolymers containing a high 3HHx monomer fraction demonstrated soft and flexible mechanical properties.Malaysia. Ministry of Science, Technology and Innovation (MOSTI Techno Fund)Universiti Sains Malaysia (USM Fellowship

    An Isolated Multiport DC-DC Converter for Different Renewable Energy Sources

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    ABSTRACT: This paper presents a new isolated multiport dc-dc converter for concurrent power management of several renewable energy sources which can be of similar types. The proposed dc-dc converter uses only one controllable switch in each port to which a source is connected. It has simple configuration and minimum number of power switches. The proposed converter is applied for simultaneous maximum power point tracking (MPPT) control of a wind/solar hybrid generation system consisting of one Wind Turbine Generator (WTG) and two different Photovoltaic (PV) panels. The experimental results are provided to validate the incisiveness of using the proposed converter to achieve MPPT simultaneously for the WTG and both PV panels. KEYWORDS: Multiport converter, maximum power point tracking (MPPT), photovoltaic (PV), wind turbine generator (WTG) solar energy, wind energy. I.INTRODUCTION Nowadays, there is a growing interest in generating electricity from distributed renewable energy sources. In numerous applications, it is required to connect multiple renewable energy sources of different types to a power grid or load. The multiport DC-DC converter has been proposed to efficient power management and grid integration for the multiple origins and development in a new era in a demand quality power in remote communities[8] The proposed isolated multiport dc-dc converter for simultaneous power management of multiple renewable energy sources uses only one power electronic switch in each input port connected to a source. The proposed converter does not use any controllable switch on the secondary side of the transformer [2]-[4]. The proposed converter has the least number of switches and thereby a lower cost. The newly introduced converter is applied for power management of a wind/solar hybrid generation systems, which consists of a WTG and two varied PV panels. The power generation from solar and wind energy are designed using perturbation and observation (P&O) MPPT algorithm, in which the WTG and PV panels can be controlled at the same time and extract the maximum power. II.PROPOSED ISOLATED MULTIPORT DC-DC CONVERTER Th

    Cutting Edge: The Heat Shock Protein gp96 Activates Inflammasome-Signaling Platforms in APCs

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    Several heat shock proteins (HSPs) prime immune responses, which are, in part, a result of activation of APCs. APCs respond to these immunogenic HSPs by upregulating costimulatory molecules and secreting cytokines, including IL-1beta. These HSP-mediated responses are central mediators in pathological conditions ranging from cancer, sterile inflammation associated with trauma, and rheumatoid arthritis. We tested in this study the requirement of inflammasomes in the release of IL-1beta by one immunogenic HSP, gp96. Our results show that murine APCs activate NLRP3 inflammasomes in response to gp96 by K(+) efflux. This is shown to initiate inflammatory conditions in vivo in the absence of additional known inflammasome activators or infection. These results document a novel mechanism by which proteins of endogenous origin, the HSPs, can modulate an inflammatory response following their release from aberrant cells

    Effects of sediment flushing operations versus natural floods on Chinook salmon survival

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    Flushing is a common measure to manage and reduce the amount of sediment stored in reservoirs. However, the sudden release of large volumes of sediment abruptly increases the suspended solids concentration and alters the riverbed composition. Similar effects can be produced also by natural flood events. Do flushing operations have more detrimental impacts than natural floods? To answer this question, we investigated the impact of flushing on the survival of the Chinook salmon (Oncorhynchus tshawytscha\textit{Oncorhynchus tshawytscha}) in the Sandy River (OR, USA), assuming that sediment is flushed from hypothetical bottom gates of the, now decommissioned, Marmot Dam. The effects of several flushing scenarios are analyzed with a 2D morphodynamic model, together with habitat suitability curves and stress indicators. The results show that attention has to be paid to duration: the shorter the flushing operation, the lesser the stresses on fish survival and spawning habitats. Flushing causes high stress to salmon eggs and larvae, due to unbearable levels of suspended sediment concentrations. It also decreases the areas usable for spawning due to fine-sediment deposition, with up to 95% loss at peak flow. Without the dam, the corresponding natural flood event would produce similar effects, with up to 93% loss. The study shows that well-planned flushing operations could mimic a natural impact, but only partly. In the long-term, larger losses of spawning grounds can be expected, since the removal of fine sediment with the release of clear water from the reservoir is a lengthy process that may be undesirable due to water storage reduction

    1-(2-Bromo­benz­yl)-3-isopropyl­benz­imid­azolin-2-one

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    In the structure of the title compound, C17H17BrN2O, the central phenyl and imidazol-2-one rings are coplanar (dihedral angle between planes of 0.73 (11)°). The angles subtended by the substituents on the N atoms of the imidazol-2-one ring range from 109.71 (14)° to 128.53 (15) due to steric hindrance of these substituents with the phenyl H atoms. The carbonyl O and Br both make two weak C—H⋯O and C—H⋯Br inter­actions with two adjacent mol­ecules, thus forming an three-dimensional array

    Attendance System Using Face Recognition and Class Monitoring System

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    In this paper, we propose a system that takes the attendance of students in the lecture. This system takes the attendance automatically using face recognition. However, it is difficult to estimate the attendance exactly using each result of face recognition independently because the face detection rate is not sufficiently high. In our paper, we propose a method for estimating the attendance exactly using all the results of face recognition obtained by continuous observation. Continuous observation improves the performance for the estimation of the attendance. We constructed the attendance system based on face recognition, and applied the system to classroom lecture. In our system, we are using raspberry pi. we use OpenCv library which is installed in pi for face detection and recognition. The camera is connected to raspberry pi and student database is stored in the pi. With the help of this system time will reduce and attendance will be marked. In this paper first review similar works in the field of attendance system and recognition of face. Then, it showing our system structure and plan. At the last, experiments are implemented to provide as manifest to support our plan. The result shows that uninterrupted observation improved the performance for the approximation of the attendance
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