64 research outputs found
Comparison of phytochemicals, antioxidant and anti-cholinesterase activity of unripe and ripe fruit of sonneratia caseolaris
Sonneratia caseolaris, also known as mangrove apple produces the edible fruit which can be found mainly on tidal mud in mangroves area. Since this fruit is considered as underutilized fruit as it is not fully discovered for its potential health benefits and not fully commercialized, hence this study aimed to determine the phytochemicals contents (i.e. total flavonoid, phenolic, anthocyanins and carotenoids contents), antioxidant and anti-cholinesterase activity of different parts (flesh and stem cap) of the unripe and ripe fruit extracts. Phytochemicals, antioxidant and anti-cholinesterase activities were determined using standard methods of spectrophotometric analysis. The flesh part of unripe S. caseolaris displayed the highest total phenolic, flavonoid and carotenoid contents as compared to the other parts in 80% methanol extract with the values of 67.67±0.10 mg (GAE/g), 37.06±0.30 mg (RE/g) and 5.41±0.10 mg (BC/100 g), respectively. The flesh part of unripe S. caseolaris in 80% methanol extract exhibited the best antioxidant properties in three different assays (i.e. DPPH, FRAP and ABTS) with the values of 98.32±0.28%, 67.72±0.74 mmol/g and 91.24±1.23 mg/g, respectively. The acetylcholinesterase inhibition also was found to be higher in the flesh part of unripe 80% methanol S. caseolaris extract with 47.18±0.68% at the concentration of 250 µg/mL. Therefore, utilization of this fruit as natural antioxidant and acetylcholinesterase inhibition sources may develop new pharmaceutical and nutraceutical products
Experimental evaluation of a solar window incorporating rotationally asymmetrical compound parabolic concentrators (RACPC).
Building integrated photovoltaic (BIPV) systems have been proposed to make solar photovoltaic systems more attractive. These systems are not only capable of generating electricity, but can also contribute to minimise energy consumption in buildings by providing natural illumination, space and water heating, ventilation and shading. Despite these advantages, one of the issues that still prevents the widespread adoption of BIPV systems is their high capital cost. This paper discusses a novel type of non-imaging optical concentrator that can be used to reduce the capital cost of a BIPV system. This new concentrator, known as rotationally asymmetrical compound parabolic concentrator (RACPC), has a flat entrance aperture that facilitates integration within a double-glazing window and reduces fabrication costs. The RACPC, which has a geometrical concentration of 3.66x, also offers other advantages over conventional solar concentrators: suitability for fenestration, ease of integration with square PV cells, and passive tracking. Several experiments were carried out on a double-glazing solar window incorporating an array of 4x3 concentrator-PV cells. The experiments were carried out indoors under standard test conditions. The results show that the RACPC-PV window effectively increases the short-circuit current by a factor of over 3 at normal incidence when compared with a non-concentrated solar window. The solar window also shows an increase in maximum power generation by a factor of nearly 3
Life Cycle Assessment of a Rotationally Asymmetrical Compound Parabolic Concentrator (RACPC)
Integrating a concentrator into the building integrated photovoltaic (BIPV) design has resulted in a new technology known as the building integrated concentrating photovoltaic (BICPV). The rotationally asymmetrical compound parabolic concentrator (RACPC) is an example of a concentrator design that has been explored for use in BICPV. This paper evaluates the life cycle assessment (LCA) for the RACPC-PV module, which has never been explored before. The LCA of the RACPC-PV module has found a cost reduction of 29.09% and a reduction of 11.76% of embodied energy material manufacture when compared to a conventional solar photovoltaic (PV) module. The energy payback time for an RACPC-PV and a conventional PV was calculated to be 8.01 and 6.63 years, respectively. Moreover, the energy return on investment ratio was calculated to be 3.12 for a conventional PV and 3.77 for an RACPC-PV
Bending strength of steel fibre reinforced concrete ribbed slab panel / Amir Syafiq Samsudin … [et al.].
Nowadays, demands in the application of fibre in concrete increase
gradually as an engineering material. Rapid cost increment of material
causes the increase in demand of new technology that provides safe,
efficient and economical design for the present and future application. The
introduction ofribbed slab reduces concrete materials and thusthe cost, but
the strength of the structure also reduces due to the reducing of material.
Steel fibre reinforced concrete (SFRC) has the ability to maintain a part of
its tensile strength prior to crack in order to resist more loading compared
to conventional concrete. Meanwhile, the ribbed slab can help in material
reduction. This research investigated on the bending strength of 2-ribbed
and 3-ribbed concrete slab with steel fibre reinforcement under static
loading with a span of 1500 mm and 1000 mm x 75 mm in cross section.
An amount of 40 kg/m steel fibre of all total concrete volume was used as
reinforcement instead of conventional bars with concrete grade 30 N/mm2
.
The slab wastested underthree-point bending. Load versus deflection curve
was plotted to illustrate the result and to compare the deflection between
control and ribbed slab. Thisresearch showsthat SFRCRibbed Slab capable
to withstand the same amount of load as normal slab structure, although
the concrete volume reduces up to 20%
Potential of implementing the low concentration photovoltaic systems in the United Kingdom
This paper discusses the prospect of integrating a novel type of low concentration photovoltaic (LCPV) design known as the rotationally asymmetrical compound parabolic concentrator (RACPC) in a building in the United Kingdom. This is done by proposing a number of building integration designs to create a zero carbon building. A cost reduction analysis of installing the LCPV systems in the country is also presented. It was found that an RACPC design could reduce the LCPV module's manufacturing cost by 31.75% and the LCPV module's cost per unit power output by 33.87% when compared with the conventional PV module
Simulating the annual energy yield of a rotationally asymmetrical optical concentrator.
This paper simulates the annual energy yield of a concentrator called the rotationally asymmetrical dielectric totally internally reflective concentrator (RADTIRC). One specific design of the RADTIRC is assumed to be installed in Berlin/Brandenburg, Germany. Simulation and experimental work have been carried out to determine the optical concentration gain under direct and diffuse radiations. Based on the analysis, it was found that the yearly energy yield was increased by a factor of 2.29 when the RADTIRC-PV module was used when compared with the non-concentrating PV module
Novel optical concentrator technology for building integrated photovoltaic systems.
This paper describes a novel type of solar concentrator for use in Building Integrated Photovoltaic (BIPV) Systems. The new design called rotationally asymmetrical compound parabolic concentrator (RACPC) is based on a novel algorithm that caters for the variation of the position of the sun throughout the day and throughout the year. The RACPC is designed to tackle the following issues: (i) to increase the electrical output of a concentrating photovoltaic (CPV) system by providing sufficient concentration gain; (ii) to minimise the usage of the PV material with the corresponding reduction of CPV system cost, and (iii) to eliminate the requirement of mechanical tracking by providing a wide field-of-view. The experimental results presented here indicate that the RACPC increases the short circuit current by 3.01x when compared with a bare solar cell
Legal and regulatory development of nuclear energy in Bangladesh.
The adequacy of legal and regulatory framework relating to nuclear energy in Bangladesh has sparked many questions since the government took the formal decision to establish a nuclear power plant (NPP) at Rooppur. Consequently, the government has taken some measures to make a comprehensive and robust framework to ensure safe and secure nuclear energy production in the country. Even though these initiatives are highly appreciable, there remain certain regulatory concerns which this paper has attempted to reflect. Therefore, the objective of this paper is to showcase the recent legal and regulatory development of Bangladesh in relation to nuclear energy and to recommend further developments. The study was based on secondary sources where a doctrinal research was carried out to solve particular research questions. The safety and security of the Rooppur Nuclear Power Plant will frankly rely on how the government of Bangladesh plans and learns to implement, design, safeguard, exchange and further develop nuclear energy related knowledge and talent around the country
Energy revolution for our common future: an evaluation of the emerging international renewable energy law
Climate change poses profound threats to the Earth and its people. Its mitigation, therefore, demands common but differentiated actions with comprehensive and coordinated approach. The global community has pledged to mitigate various greenhouse gases in some international soft law instruments. Exploitation of renewables to generate energy and produce electricity is simultaneously suggested for the last couple of decades as a viable alternative in mitigating climate change. This gets momentum with the adoption of the historical and universally ratified Paris Agreement in 2016 where energy is placed at the heart of the Agreement. Energy, where renewable energy is a branch, is generally regulated and governed domestically and so, international legal regime is still evolving in this regard. In the absence of any specific and direct international instrument on energy and renewable energy, published literatures have considered this topic from different directions ranging from climate change to the principle of national sovereignty, economic, trade and investment issues. In this backdrop, this paper aims to introduce various renewable sources, prospects and challenges in their promotion that may help to mitigate the adverse effects of climate change. Relevant international law provisions have been evaluated, performances of the relevant regional and international organizations active in this sector are highlighted and some of the disputes in this area considered in international forums are duly addressed. It is revealed that strong political will of the global community in fulfilling their commitments made so far in different international forums is the key to transforming the world into a better one for the future generation
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