19672 research outputs found
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Evaluation of solid oxide fuel cell based polygeneration system in residential areas integrating with electric charging and hydrogen fueling stations for vehicles
No full textThis study proposes a design of polygeneration system based on solid oxide fuel cell to supply electricity, hot water, cooling, and hydrogen. This system also integrates the stationary supply for electric and hydrogen cars. The polygeneration system is developed based on energy, economic and environment simulation models by taking into account its application for the residential building. Four system configurations were designed based on the grid connection and the vehicle type and subsequently evaluated to determine the performance of the system in regard to the criteria such as efficiency, reliability, primary energy saving, cost saving as well as carbon dioxide reduction. Moreover, a strategy of selling the available hydrogen was also considered to analyze the competitiveness of the proposed system with the conventional separated system. Depending on these criteria, analysis of fuel cell size with respect to the coverage of demands was also conducted. The proposed system achieved primary energy savings, cost saving and emission reduction of about 73%, 50% and 70% respectively. The hydrogen selling strategy has a significant effect in reducing energy cost close to 51% for the configuration with electric vehicle station. © 2019 Elsevier Lt
Short-Term Electricity Price Forecasting via Hybrid Backtracking Search Algorithm and ANFIS Approach
No full textIn this paper, a hybrid electricity price forecasting method which is composed of two-stage feature selection method and optimized adaptive neuro-fuzzy inference system (ANFIS) technique as a forecasting engine is proposed to accurately forecast electricity price. A multi-objective feature selection approach comprises of multi-objective binary-valued backtracking search algorithm (MOBBSA) as an efficient evolutionary search algorithm and ANFIS method is developed in this paper to extract the most influential subsets of input variables with maximum relevancy and minimum redundancy. Through the combination of backtracking search algorithm (BSA) in learning process of ANFIS approach, a hybrid machine learning algorithm has been developed to forecast the electricity price more accurately. Real-world electricity demand and price dataset from Ontario power market; which is reported as among the most volatile market worldwide, has been used as case study to validate the performance of the proposed approach. From the simulation results, it has been seen that the proposed hybrid forecasting method was effective in accurately forecast the Ontario electricity price. In addition, to prove the superiority of the proposed hybrid forecasting method the simulation results obtained using ANN and ANFIS models optimized by other well-known optimization methods have been compared with that of proposed method. © 2019 IEEE
The intermediary effect of nationalism on the relationship of religion, values, and culture with unity among pre-service teachers in Malaysia
No full textThis study aims to determine the mediating effect of nationalism on the relationship of religion, value, and culture with unity among pre-service teachers in the higher learning institutions of Malaysia. A total of 230 teachers with different racial backgrounds were recruited, among whom 133 were Malays and 97 were non-Malays. The data were analyzed using SPSS 23 and AMOS 18. Nationalism has a significant yet partial mediating effect on the relationship of religion, value, and culture with unity among pre-service teachers. The MANOVA analysis revealed a significant difference in such relationship between Malay and non-Malay students. The AMOS analysis showed that culture and religion had the highest and lowest effects on nationalism and unity, respectively. These findings imply that the Ministry of Higher Learning, universities, and lecturers in Malaysia must focus on the aspects of culture, religion, values, and nationalism to enhance the unity among pre-service teachers in the country. © Universiti Putra Malaysia Press
Universalization of Indonesian cultural and scientific regulations
No full textIndonesia ratified the agreement on the establishment of the World Trade Organization, including its annex agreement, the Trade-Related Aspects of Intellectual Property Rights (TRIPS) in 1995. The alignment of Indonesian Intellectual Property Rights (IPRs) with that of the WTO’s TRIPS has been made easy owing to shared universal human principles that emanated from the country's constitution that was established at the time of independence. Consequently, Indonesia has transformed its legal system to be in sync with the United Nations Bill of Rights. While the WTO's TRIPS Agreement focused heavily on IPRs to which Indonesia’s contribution by way of filings has been low, Indonesia offers other countries lessons in the more subtle area of public order and morality. Community-based IPRs have emerged as a new area of interest in international fora, which has led to the recognition of traditional sources of knowledge, traditional cultural expressions and intangible cultural heritage. It is in this context that the Ten Principles of Bandung on cultural equality is examined to provide an illuminating account of how the harmonization of universal IPRs can help promote cultural equality for the benefit of society globally. The Five Principles of Indonesia’s constitution evolved to recognize the diversity generated from around 1300 indigenous communities in Indonesia. This paper provides an elucidating account of interventions to protect public order and morality using the examples of the Buddha Bar case, the Tropic Effect and the Wayang Golek statues. The manner in which the Indonesian government acted to protect public order and morality offers an incisive narrative towards strengthening universal regulations on cultural equality. © 2019, © 2019 African Journal of Science, Technology, Innovation and Development
Efficient deoxygenation of triglycerides to hydrocarbon-biofuel over mesoporous Al2O3-TiO2 catalyst
No full textThe renewable hydrocarbon-like biofuel from biomass is crucial to substitute fossil fuel. A series of mesoporous Al2O3-TiO2 mixed oxide catalysts with different TiO2 content (0.1Ti-0.9Al, 0.2Ti-0.8Al and 0.3Ti-0.7Al) have been synthesized. The physicochemical properties of the catalysts were characterized by XRD, FESEM-EDX, BET, FTIR, NH3-TPD, FTIR-Py, and TGA. The deoxygenation (DO) of triglyceride (i.e. triolein) was carried out in the absence of hydrogen and solvent. The mesoporous Al2O3-TiO2 catalysts showed high catalytic activity performance as compared to that of Al2O3 and TiO2. It was found that 0.2Ti-0.8Al catalyst exhibited the highest conversion (76.86%), and selectivity (27.26%) toward n-C15 + n-C17 at 380 °C after 4 h. The excellence performance of mesoporous Al2O3-TiO2 was attributed to its acidity, mesoporosity and larger surface area. The results reveal that the mesoporous Al2O3-TiO2 catalyst is a promising catalyst for the synthesis of hydrocarbon-like biofuel. © 2019 Elsevier B.V
Biodiesel production from Calophyllum inophyllum-Ceiba pentandra oil mixture: Optimization and characterization
No full textIn this study, a novel modeling approach (artificial neural networks (ANN) and ant colony optimization (ACO)) was used to optimize the process variables for alkaline-catalyzed transesterification of CI40CP60 oil mixture (40 wt% of Calophyllum inophyllum oil mixed with 60 wt% of Ceiba pentandra oil) in order to maximize the biodiesel yield. The optimum values of the methanol-to-oil molar ratio, potassium hydroxide catalyst concentration, and reaction time predicted by the ANN-ACO model are 37%, 0.78 wt%, and 153 min, respectively, at a constant reaction temperature and stirring speed of 60 °C and 1000 rpm, respectively. The ANN-ACO model was validated by performing independent experiments to produce the CI40CP60 methyl ester (CICPME) using the optimum transesterification process variables predicted by the ANN-ACO model. There is very good agreement between the average CICPME yield determined from experiments (95.18%) and the maximum CICPME yield predicted by the ANN-ACO model (95.87%) for the same optimum values of process variables, which corresponds to a difference of 0.69%. Even though the ANN-ACO model is only implemented to optimize the transesterification of process variables in this study. It is believed that the model can be used to optimize other biodiesel production processes such as seed oil extraction and acid-catalyzed esterification for various types of biodiesels and biodiesel blends. © 2019 Elsevier Lt
Feedback passivation plus tracking-error-based multivariable control for a class of free-radical polymerisation reactors
No full textThis paper proposes a tracking-error-based multivariable control to stabilise a nonlinear system at the desired trajectory (including the open-loop unstable equilibrium manifold). The control approach is developed on the basis of feedback passivation and then applied to stabilise globally exponentially a class of free-radical polymerisation reactors. More precisely, under certain conditions the system dynamics can be rendered strictly input/output passive through the use of an appropriate input coordinate transformation. A canonical form related to the so-called port-Hamiltonian representation of passive system is consequently derived and provides physical interpretations such as dissipative/non-dissipative term and supply rate. A feedback law based on tracking-error is then designed for the global exponential stabilisation at a reference trajectory passing through the desired set-point. The theoretical developments are illustrated for polystyrene production in a continuous stirred tank reactor. Numerical simulations show that the system trajectory converges globally exponentially to the reference trajectory despite effects of disturbance. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group
Kinematics of the M87 Jet in the Collimation Zone: Gradual Acceleration and Velocity Stratification
No full textWe study the kinematics of the M87 jet using the first-year data of the KVN and VERA Array (KaVA) large program, which has densely monitored the jet at 22 and 43 GHz since 2016. We find that the apparent jet speeds generally increase from ≈0.3c at ≈0.5 mas from the jet base to ≈2.7c at ≈20 mas, indicating that the jet is accelerated from subluminal to superluminal speeds on these scales. We perform a complementary jet kinematic analysis by using archival Very Long Baseline Array monitoring data observed in 2005-2009 at 1.7 GHz and find that the jet is moving at relativistic speeds up to ≈5.8c at distances of 200-410 mas. We combine the two kinematic results and find that the jet is gradually accelerated over a broad distance range that coincides with the jet collimation zone, implying that conversion of Poynting flux to kinetic energy flux takes place. If the jet emission consists of a single streamline, the observed trend of jet acceleration (Γ ∝ z 0.16±0.01) is relatively slow compared to models of a highly magnetized jet. This indicates that Poynting flux conversion through the differential collimation of poloidal magnetic fields may be less efficient than expected. However, we find a nonnegligible dispersion in the observed speeds for a given jet distance, making it difficult to describe the jet velocity field with a single power-law acceleration function. We discuss the possibility that the jet emission consists of multiple streamlines following different acceleration profiles, resulting in jet velocity stratification. © 2019. The American Astronomical Society. All rights reserved
Enhancement of C-phycocyanin purity using negative chromatography with chitosan-modified nanofiber membrane
No full textIn this work, a chitosan-modified nanofiber membrane was fabricated and used to examine the permeation characteristics of C-phycocyanin (CPC) obtained from Spirulina platensis. The effects of NaCl concentration (0.1–1.0 M), chitosan coupling pH (6–8), chitosan coupling concentration (0.1–3.0%), algal solution pH (6–8), algal mass concentration (0.1–1.0% dw/v), and membrane flux (4.08 × 10 −2 –2.04 × 10 −1 mL/min·cm 2 ) on the penetration performance of the membrane for CPC were investigated. The results show that the order of binding selectivity of the membrane for these proteins is contaminating proteins (TP) > allophycocyanin (APC) > CPC. TP and APC molecules were more easily adsorbed by the chitosan-modified membrane, and the CPC molecules most easily penetrated the membrane without being adsorbed, enhancing CPC purity. The purification factor and total mass flux were 3.3 fold and 66%, respectively, in a single step. © 2019 Elsevier B.V
Potential toxicity effects of Anastatica hierochuntica aqueous extract on prenatal development of Sprague-Dawley rats
No full textEthnopharmacological relevance: Anastatica hierochuntica (A. hierochuntica) is a plant consumed in folk medicine for the treatment of reproductive system related problems and metabolic disorders. It is of concern that the herb is commonly consumed by pregnant women towards the end of pregnancy to ease the process of labour, despite the lack of studies evaluating its safety. Aim of this study: This study aimed to investigate the potential toxicity effects of A. hierochuntica in pregnant Sprague-Dawley rats and their developing foetuses. Materials and methods: Experiments were conducted in accordance to the Organisation for Economic Co-operation and Development guideline 414. Animals were randomly divided into four groups (n = 10 females per group): negative control (received the vehicle only), experimental animals received 250, 500, and 1000 mg/kg A. hierochuntica aqueous extracts (AHAE), respectively. Treatment was administered daily by oral gavage from gestational day (GD) 6–20, and caesarian section performed on GD21. Results: There were significant reduction in the corrected maternal weight gain of dams and body weight of foetuses in the lowest and highest dose of AHAE-treated animals compared to the control. These findings were associated with the increase in anogenital distance index and multiple congenital anomalies observed in some of the offspring. On the other hand, rats treated with 500 mg/kg showed higher embryonic survival rate with absence of significant treatment-related effect. Conclusion: Findings showed that highest and lowest doses of AHAE have prenatal toxicity effects in SD rats. Therefore, AHAE is potentially harmful to the developing foetuses especially when consumed during the period of implantation and organogenesis. As for the rats treated with 500 mg/kg AHAE, there was no significant treatment-related effect. Hence, we postulate that this finding suggests that the disruption on the hormonal regulation could have been compensated by negative feedback response. The compensated effects of AHAE at 500 mg/kg and the presence of lowest observed adverse effect level (LOAEL) at 250 mg/kg has resulted in a non-monotonous dose response curve (NMDRC), which complicates the determination of the value of no-observed-adverse effect level (NOAEL). © 2019 Elsevier B.V