158 research outputs found

    Life cycle assessment (LCA) of electricity generation from rice husk in Malaysia

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    AbstractThis paper evaluated the life cycle analysis (LCA) of electricity derived from rice husk combustion in the Malaysia rice mills. Due to environment and security constraint cause by fossil fuel, biomass like rice husk becomes an attractive solution to look at. However, the environment profile of the electricity production from rice husk must be assessed to ensure it environment safety. The unit processes that make up the system are the paddy production, transportation to the rice mill, rice mill processing and combustion of rice husk to generate electricity. This study used functional unit as, 1.5MWh of electricity generating at the energy plant. The result show transportation contributes more to climate change compare to other process. Then, the characterized data from rice huskderived electricity is compared with coal and natural gas derived electricity. The results indicate the performance of rice husk derived-electricity is better in the aspect of environment impact parameters

    Cost-benefit analysis and emission reduction of energy efficient lighting at the Universiti Tenaga Nasional.

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    This paper reports the result of an investigation on the potential energy saving of the lighting systems at selected buildings of the Universiti Tenaga Nasional. The scope of this project includes evaluation of the lighting system in the Library, Admin Building, College of Engineering, College of Information Technology, Apartments, and COE Food court of the university. The main objectives of this project are to design the proper retrofit scenario and to calculate the potential electricity saving, the payback period, and the potential environmental benefits. In this survey the policy for retrofitting the old lighting system with the new energy saving LEDs starts with 10% for the first year and continues constantly for 10 years until all the lighting systems have been replaced. The result of the life cycle analysis reveals that after four years, the selected buildings will bring profit for the investment

    Prioritising urban green spaces using accessibility and quality as criteria

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    Urban green spaces are a critical component of cities, providing environmental, social, cultural, and economic benefits. To support smart(er) decisions by city planners and managers, this study aims to investigate how open data sources could be integrated into urban green space management. Specifically, it proposes a novel GIS-based method to prioritise urban green space in a resource-constraint scenario so that social benefits are maximised. To quantify the social benefits, the methodology is based on the WHO indicator, which recommends access to at least 0.5-1 ha of green space within 300 metres\u27 linear distance to all the city residents. The approach assigns each urban green space an \u27accessibility score\u27 based on its significance in the city, and a \u27quality score\u27 based on its performance on different quality parameters (size, greenness, quietness, and safety). Urban green spaces are ranked with respect to these two scores, enabling to prioritise spaces under resource constraints such as water shortage, limited staff, or budget. This approach is demonstrated through a case study on a mid-size German city and is transferable to other cities worldwide with varying weightage factors

    Water distribution system design integrating behind-the-meter solar under long-term uncertainty

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    Water distribution systems (WDSs) are important urban water infrastructure supporting a wide range of human activities. Due to the significant amount of energy consumed by the WDS throughout its lifespan, the operation of WDSs may have a significant impact on the environment, affecting the sustainable development of cities into the future. Behind-the-metre (BTM) solar photovoltaic (PV) system integration has been considered an effective way to reduce the impact of WDSs on the environment. However, solar PV technology is developing rapidly. Combined with long-term changes in water demand driven by population growth and urbanisation, the design of a WDS considering BTM solar has become a more challenging task. In this study, the co-design of WDS integrating BTM solar PV systems under changing future conditions in terms of water demand and solar PV technology development is investigated. It has been found that the BTM solar PV system and the potential development in solar PV technology effectively improve the robustness of WDS design under uncertain future water demand. The outcomes of this study can be extended to guide infrastructure design to provide sustainable infrastructure for future cities, and therefore cities can continue to support human activities in deeply uncertain future.Jiayu Yao, Wenyan Wu, Angus R. Simpson, Behzad Rismanch

    Compressed-Liquid Energy Storage with an Adsorption-based Vapor Accumulator for Solar-Driven Vapor Compression Systems in Residential Cooling

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    A cycle-integrated energy storage strategy for vapor-compression refrigeration is proposed wherein thermo-mechanical energy is stored as compressed liquid.A compressed-liquid tank is integrated into the liquid line of the system by means of an adsorption-based vapor accumulator in the vapor line. Energy is retrieved through expansion of the compressed liquid, which allows for a tunable evaporator temperature. A thermodynamic model is developed to assess the system performance, with storage incorporated, for solar residential cooling in two locations with contrasting ambient temperature profiles. Ammonia, R134a, and propane, all paired with activated carbon as adsorbent, are evaluated.A high cold thermal energy storage density is achieved when operated with ammonia. However, the accumulator suppresses the coefficient of performance of the system because work is required to extract refrigerant from the adsorbent. Practical feasibility of the proposed storage strategy calls for the development of nontoxic refrigerant–adsorbent pairs with more favorable adsorption behavior

    An intramolecular salt bridge drives the soluble domain of GTP-bound atlastin into the postfusion conformation

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    Before ER tubule fusion, the atlastin GTPase undergoes a “prefusion” to “postfusion” conformational change that is mediated by an intramolecular salt bridge

    Diffusion and retention are major determinants of protein targeting to the inner nuclear membrane

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    Newly synthesized membrane proteins are constantly sorted from the endoplasmic reticulum (ER) to various membranous compartments. How proteins specifically enrich at the inner nuclear membrane (INM) is not well understood. We have established a visual in vitro assay to measure kinetics and investigate requirements of protein targeting to the INM. Using human LBR, SUN2, and LAP2 beta as model substrates, we show that INM targeting is energy-dependent but distinct from import of soluble cargo. Accumulation of proteins at the INM relies on both a highly interconnected ER network, which is affected by energy depletion, and an efficient immobilization step at the INM. Nucleoporin depletions suggest that translocation through nuclear pore complexes (NPCs) is rate-limiting and restricted by the central NPC scaffold. Our experimental data combined with mathematical modeling support a diffusion-retention-based mechanism of INM targeting. We experimentally confirmed the sufficiency of diffusion and retention using an artificial reporter lacking natural sorting signals that recapitulates the energy dependence of the process in vivo

    Disruption of Axonal Transport in Motor Neuron Diseases

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    Motor neurons typically have very long axons, and fine-tuning axonal transport is crucial for their survival. The obstruction of axonal transport is gaining attention as a cause of neuronal dysfunction in a variety of neurodegenerative motor neuron diseases. Depletions in dynein and dynactin-1, motor molecules regulating axonal trafficking, disrupt axonal transport in flies, and mutations in their genes cause motor neuron degeneration in humans and rodents. Axonal transport defects are among the early molecular events leading to neurodegeneration in mouse models of amyotrophic lateral sclerosis (ALS). Gene expression profiles indicate that dynactin-1 mRNA is downregulated in degenerating spinal motor neurons of autopsied patients with sporadic ALS. Dynactin-1 mRNA is also reduced in the affected neurons of a mouse model of spinal and bulbar muscular atrophy, a motor neuron disease caused by triplet CAG repeat expansion in the gene encoding the androgen receptor. Pathogenic androgen receptor proteins also inhibit kinesin-1 microtubule-binding activity and disrupt anterograde axonal transport by activating c-Jun N-terminal kinase. Disruption of axonal transport also underlies the pathogenesis of spinal muscular atrophy and hereditary spastic paraplegias. These observations suggest that the impairment of axonal transport is a key event in the pathological processes of motor neuron degeneration and an important target of therapy development for motor neuron diseases
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