bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectral properties of the surface reflectance of the northern polar region of Mercury
Authors: Ngoc Nguyen Bich , Bott Nicolas , Diep Pham Ngoc 
Published: April 2020

Abstract
We analyze MESSENGER reflectance measurements covering the northern polar region of Mercury, the least studied region of the northern mercurian hemisphere. We use observations from the Mercury Dual Imaging System Wide-Angle Camera (MDIS/WAC) and the Mercury Atmospheric and Surface Composition Spectrometer (MASCS/VIRS) to study the spectral dependence of the surface reflectance. The results obtained from the observations made by both instruments are remarkably consistent. We find that a second degree polynomial description of the measured reflectance spectra gives very good fits to the data and that the information that they carry can best be characterized by two parameters, the mean reflectance and the mean relative spectral slope, averaged over the explored range of wavelengths. The properties of the four main types of terrains known to form Mercury’s regolith in the northern region, smooth plains (SPs), heavily cratered terrain (HCT), fresh ejecta/materials and red pitted ground (RPG), are examined in terms of these two parameters. The results are compared, and found consistent with those obtained by earlier studies in spite of difficulties met in obtaining accurate reflectance measurements under the large incidence angle condition characteristic of polar regions. These results will help with the preparation of the BepiColombo mission and with supporting its observational strategy.
Searching for exoplanets by HEPS II. detecting earth-like planets in habitable zone around planet hosts within 30 pc
Authors: Yu Zhou-Yi , Liu Hui-Gen , Zhou Ji-Lin , Liang En-Si , Yang Ming , Zhang Hui , Liu Jia-Cheng 
Published: April 2020

Abstract
HEPS (Habitable ExoPlanet Survey) is a planning astrometry satellite that aims to find Earth-like planets in the solar neighbourhood. In this paper, we selected 140 planet harboring stars within 30 pc of the solar system to be potential targets for HEPS. We calculate the detection probability of the planet in habitable zone (HZ) for each system using the simulated data of astrometry measurements. For those host stars without planets in HZ, we inject an additional planet of 10 M
⊕ in their HZs and check the stability of the systems. Considering five observation modes of different sampling cadence and total observation time, we obtain a table containing the total detection probability of the planets in HZs for all of the 140 selected systems. This paper provides a potential ranked list of target stars for HEPS, or other astrometric mission to detect Earth-like planets in the future. We also calculate an empirical fitted expression of the detection probability as a function of both sampling cadence and total observation time. We conclude a quantitative method to estimate the detection probability for certain planet hosts and observation modes via the empirical expression. We show the minimum requirements of both sampling cadence and observation time for Proxima Centauri, HD 189733 and HD 102365, if the detection probability of habitable-zone planets of these three systems needs to be 90%.
A study on the dynamic spectral indices for SEP events on 2000 July 14 and 2005 January 20
Authors: Zhao Ming-Xian , Le Gui-Ming 
Published: April 2020

AbstractWe have studied the dynamic proton spectra for the two solar energetic particle (SEP) events on 2000 July 14 (hereafter GLE59) and 2005 January 20 (hereafter GLE69). The source locations of GLE59 and GLE69 are N22W07 and N12W58 respectively. Proton fluxes >30 MeV have been used to compute the dynamic spectral indices of the two SEP events. Our results show that spectral indices of the two SEP events increased more swiftly at early times, suggesting that the proton fluxes >30 MeV might be accelerated particularly by the concurrent flares at early times for the two SEP events. For the GLE69 with source location at N12W58, both flare site and shock nose are well connected with the Earth at the earliest time. However, only the particles accelerated by the shock driven by eastern flank of the CME can propagate along the interplanetary magnetic field line to the Earth after the flare. For the GLE59 with source location at N22W07, only the particles accelerated by the shock driven by western flank of the associated CME can reach the Earth after the flare. Our results also show that there was slightly more than one hour during which the proton spectra for GLE69 are softer than that for GLE59 after the flares, suggesting that the shock driven by eastern flank of the CME associated with GLE69 is weaker than the shock driven by the western flank of the CME associated with GLE59. The results support that quasi-perpendicular shock has stronger potential in accelerating particles than the quasi-parallel shock. These results also suggest that only a small part of the shock driven by western flank of the CME associated with the GLE59 is quasi-perpendicular.
Dynamics of scrape-off layer filaments in detached conditions
Authors: Schwörer D. , Walkden N.R. , Dudson B.D. , Militello F. , Leggate H. , Turner M.M. 
Published: April 2020

Abstract
The here presented work studies the dynamics of filaments using 3D fluid simulations in the presence of detached background profiles. It was found that evolving the neutrals on the time-scale of the filament did not have a significant impact on the dynamics of the filament. In general a decreasing filament velocity with increasing plasma background density has been observed, with the exception of detachment onset, where a temporarily increase in radial velocity occurs. The decreasing trend with temporary increase was found for filaments around the critical size and larger, while smaller filaments where less affected by detachment. With detachment the critical filament size increased, as larger filaments were faster in detached conditions. This breaks the trend of attached conditions, where the critical size decreases with increasing density.
Energy infrastructure, NIMBYism, and public opinion: a systematic literature review of three decades of empirical survey literature
Authors: Carley Sanya , Konisky David M , Atiq Zoya , Land Nick 
Published: April 2020

Abstract
Public support is a key determinant of whether any energy project is developed in democratic countries. In recent decades, scholars have extensively examined levels of support and opposition to energy infrastructure, often with a focus on so-called Not-in-My-Backyard (NIMBY) sentiments. As the need for energy infrastructure grows, so does the need to extract insights and lessons from this literature. In this systematic literature review, we evaluate decades of research to identify important trends in topical focus, research findings, and research design. We find a disproportionate focus on wind energy, followed by solar, fossil fuels, and transmission, with most studies conducted in the United States or United Kingdom, and that individuals are more often supportive of energy projects than they are opposed. Scholars have examined the role of many factors in understanding attitudes toward energy infrastructure, and often find knowledge, trust, and positive perceptions about the benefits of projects to be positively correlated with support for projects, although with variation across energy types. NIMBY attitudes differ widely in approach and are often plagued by problematic research designs that limit inferences and the generalizability of findings. We provide a detailed discussion of these limitations and suggest areas in which the literature can expand.
The effect of gasoline-waste plastics oil blends on SI engine performance at high-speed rotation
Authors: Khairil  , Jihad Muhammad , Indra Riayatsyah Teuku Meurah , Bahri Samsul , Sofyan Sarwo Edhy , Jalaluddin  
Published: April 2020

Abstract
As well known that waste plastic could be considered a very serious environmental issue because of their disposal problems may affect human life. One of the solutions to solve the plastic waste problem is to convert the plastic waste become plastic oil. This research was aimed to study the effect of gasoline-waste plastics oil (WPO) blends on (SI) engine performance at high-speed rotation. In this experiment, the engine of Honda GP 160 H-SD was selected which has specification a single-cylinder spark ignition, power is 5.5 HP and output net 3600 rpm. The composition of gasoline-waste plastic oil blends was variated of about WPO-10, WPO-20 and WPO-30. WPO-10 means that the waste plastic oil was added in gasoline oil of about 10 % vol. The SI engine performance was elucidated such as engine power, specific fuel consumption and thermal efficiency. The experimental results show that increasing speed rotation from 1500 to 3000 rpm greatly increases engine output power and specific fuel consumption. Consequently, the thermal efficiency reduced by 21.1%. It is also found, the increasing of blending ratio to WPO-30 has dropped the SI engine power approximately by 10.3 %. As results the specific fuel consumption reduced by 17.4 % while thermal efficiency can be increased by 15.5 %.
Test of a modified small-scale biochar kiln
Authors: Petchaihan Lalita , Panyoyai Numpon , Khamdaeng Tipapon , Wongsiriamnuay Thanasit 
Published: April 2020

AbstractThe conventional kilns were used for biochar production, but it took more than 7-9 hours for processing, and its process temperature was not uniform because some of the material could be converted into biochar and used lots of heat source input resulting in low production efficiency. Then the objective of this research was to improve the biochar production by using modified biochar kiln by reducing the temperature distribution. A 50-liter kiln with a modified core was needed in this research. This core was heating source for the pyrolysis process. The heat source came from the combustion of biomass. The core pipe was core puncture diameter for releasing product gas between a process, and it was core puncture diameter in 3 sizes (i.e., 3.18 mm, 4.76 mm and 6.35 mm). Seven kilograms of corncob rice husk and longan peel were loaded in the biochar kiln using three kilograms of fuel. The physical and chemical properties of biochar were analyzed such as water content, pH, electrical conductivity (EC) using scanning electron microscope (SEM), and Energy-dispersive X-ray spectroscopy (EDX). The element and mineral compositions were also analyzed, including C, N, O, K, and P. It was found that most of the materials were converted into biochar at uniform temperature with the modified core. The temperature inside a kiln with the heat insulation the modified core was around 400-600°C better than the common core (100-700°C) and it took only 3 hours for the process. In terms of products obtained from pyrolysis condition, the average temperature positions inside the kiln were found to be 430 ± 583 °C, 271 ± 512 °C, and 189 ± 503 °C and consisted of biochar yield were found to be 45.7, 34. 3 and 31.4 wt.% for rice husk, corncob, and longan peel, respectively. Gas yields were found to be 68.6, 68.6, and 48.6 wt.% for longan peel, corncob, and rice husk, respectively Ash yields were found to be 10.0, 5.7, and 5.7 wt.%, for longan peel, corncob, and rice husk, respectively. The biochar properties from corncob rice husk and longan peel were beneficial, resulting in being useful for the soil amendment. It had suitable properties for improving the deteriorated soil structure conditions.
Effect of process conditions on properties of biochar from agricultural residues
Authors: Somparn Waranya , Panyoyai Numpon , Khamdaeng Tipapon , Tippayawong Nakorn , Tantikul Samerkhwan , Wongsiriamnuay Thanasit 
Published: April 2020

AbstractIn northern Thailand, there are a great amount of agricultural residues generated after the harvest, most of which are burned as a means of disposal, affecting the soil for agriculture, wild animals, as well as causing air pollution. One of the solutions that may be beneficial in terms of carbon credit is to turn these agricultural residues into biochar using slow pyrolysis. Biochar is widely accepted biologically derived matter with the ability to contain carbon, large amount of nutrients, adding biodiversity in soils. The attribute of biochar is varied depending on its production process. This research aims to study biochar production conditions and possible attributes with slow pyrolysis process under 100 ml/min nitrogen condition. Two types of agricultural residues including rice husk and corn cob were used, at the process temperature of 300-700 °C. The results indicated that when the temperature was increased, the produced biochar decreased, but different amounts of carbon, electrical conductivity, amounts of inorganic minerals (N, P, K, Mg, Ca, Fe), and alkalinity increased. This enabled the produced biochar to add more carbon to the soil when used, reduce acidity or alkalinity, as well as help the soil to contain more water and other required nutrients for plants better and become a home to microbe. More air ventilation was allowed in the soil, improving its quality.
Briquette production from rice husk by using screw compaction
Authors: Saneewongnaayuttaya Narongrit , Panyoyai Numpon , Khamdaeng Tipapon , Wongsiriamnuay Thanasit 
Published: April 2020

Abstract
Most of the agricultural residues have low density resulting in increasing the cost of storage and transportation. With the reduced volume by the compacting process, density and other properties are increased while the storage and transportation space and cost can be reduced. The effects of screw characteristics on the briquette qualities were measured. The process condition for producing fuel briquettes with screw extruders can be used as renewable energy in the industry. Rice husk was collected and its moisture content was reduced around 8-12%. A screw used as feeding and compacting with a length of 45 centimeters and 19 degrees of screw tip angle. The mold temperatures were around 300-400 degrees Celsius. Three lengths of the screw were tested. While the briquette properties were analyzed, such as density durability, an expansion length, heating value, and moisture content of fuel briquettes after the compression process. The experimental results showed that the suitable compression condition for agricultural materials was in the range of 45.9 cm screw length and mold temperature in the range of 330 - 360 degrees Celsius. The briquettes had a durability of 98.67%, a density of 0.846 g/cm3, expansion ratio of 1.1853 %, the heat value of 3813 cal / g, moisture content after compression of 1.9% w.b. and capacity of 112.8 kg/hr. Increasing the screw length improved the performance of compression, continuous working, and briquette fuel quality. Reducing the screw length required a higher mold temperature, leading to the failure of continuous working, defective machines due to extra burden and deteriorating quality of fuel briquettes.
A scheduling and planning algorithm for microalgal cultivation and harvesting for biofuel production
Authors: San Juan J L G , Mayol A P , Sybingco E , Ubando A T , Culaba A B , Chen W H , Chang J S 
Published: April 2020

Abstract
Microalgae is highlighted as the most feasible bioenergy feedstock because it can produce high amounts of lipids, carbohydrates, and hydrogen, which are necessary compounds for the production of various biofuels, while only requiring minimal water and land due to high photosynthetic efficiency. However, there are technical limitations that negatively influence the mass production of biofuel from algae, making it economically infeasible on a commercial scale. One of these bottlenecks exist in its cultivation. The cultivation method and system are critical in determining the amount and quality of biofuel that may be generated from the microalgae. Additionally, the peak biomass concentration, and productivities for the different compounds and nutrients within microalgae do not occur at the same time. Hence, this work proposes a planning tool for microalgae cultivation systems that incorporates species selection, and cultivation and harvesting approach selection and scheduling, while balancing the minimization of environmental impact and maximization of profit realized. The capabilities of the proposed decision support model is demonstrated through a hypothetical case study. Scenario analyses is likewise conducted to establish an understanding of system behavior and performance over time and under various conditions. The results of the computational experiments show the tools capabilities in simultaneously considering algae growth rates and compound productivities in decision making, for instance biomass species that is able to generate the most of a certain high value fuel is prioritized in cultivation and harvesting.
Developing an artificial neural network model for predicting the growth of Chlorella sorokiniana in a photobioreactor
Authors: Magdaong J B , Culaba A B , Ubando A T , Chang J S , Chen W H 
Published: April 2020

Abstract
Microalgae have been long considered as a potential source of biofuel. Species such as Chlorella sorokiniana can store large amounts of carbohydrates and lipids which can be used to produce biofuels. This paper demonstrates a method for developing an artificial neural network model which can predict C. sorokiniana growth in a photobioreactor. The data used for training the model came from cultivation experiments conducted at the National Cheng Kung University in Taiwan. A feedforward backpropagation ANN model with three inputs (i.e. aeration rate, biomass concentration, and nitrate concentration) and two targets (i.e. biomass concentration and nitrate concentration after 24 hours) was used for this study. Using MATLAB, multiple configurations of this ANN model were created and tested by varying the number of neurons and hidden layers and the training algorithm. Models were initially assessed in terms of their mean square error (MSE) and training performance plots. The models were then further assessed based on their simulation capabilities. After setting the initial biomass and nitrate concentration and aeration profile, the model can already predict the daily biomass and nitrate concentration of C. sorokiniana for the whole cultivation period. The final model selected has one (1) hidden layer and four (4) hidden neurons and it was trained using the Bayesian regularization backpropagation algorithm. For the final selected model, the calculated mean absolute percentage error (MAPE) for the predicted daily biomass and nitrate concentration were all below 7.59% and 3.68% respectively. Thus, the simulation results showed that the final model can accurately predict C. sorokiniana growth at varying aeration profiles. For future studies, this model can be used to determine the aeration profile that can maximize C. sorokiniana growth in a photobioreactor while minimizing aeration costs.
Kinetic modelling study of cyclo-alkane oxidation for transportation fuels
Authors: Tan Johnin , Poon Hiew Mun , Saw Lip Huat 
Published: April 2020

Abstract
Cyclo-alkanes are the major constituents of hydrocarbons in market fuels such as petrol, diesel, and aviation fuels. Diesel fuels derived from bituminous sands have up to 30 % of cyclo-alkanes. Besides that, cyclo-alkanes play a vital role in soot formation as they yield aromatic compounds through dehydrogenation. Thus, it is crucial to include cyclo-alkanes in the formulation of multi-component diesel surrogate fuel models. As a consequence, better prediction in the combustion and emission simulations can be achieved. In this study, a reduced cyclo-alkane kinetic model, namely methyl-cyclohexane (MCH) is developed for diesel engine applications. Here, the detailed MCH model with 1,540 species is served as the base model. The reduced MCH model is derived by performing mechanism reduction using five-stage reduction scheme. Accordingly, a reduced MCH model with 86 species is obtained after the reduction procedures. A 94% reduction in the mechanism size has been successfully achieved. Next, the reduced MCH model is validated against the detailed model with respect to ignition delay (ID) timings in zero-dimensional (0-D) simulations. Computed results by the reduced MCH model are in close agreement with the detailed model, with maximum deviation recorded at 33%. The reduced MCH model developed is ready to be used to represent cyclo-alkanes in multi-component diesel surrogate fuel models.
An energy analysis on the production of torrefied microalgal biomass
Authors: Rivera D R T , Culaba A B , Ubando A T , Chen W H , Chang J S 
Published: April 2020

Abstract
Torrefaction is a process for upgrading raw biomass into an energy-dense fuel. In this study, an energy analysis was conducted to assess the energy consumption in the production of torrefied microalgal biomass. The functional unit of one kilogram torrefied biomass and a system boundary of cradle-to-gate was used. This includes the life cycle stages of cultivation, harvesting, drying, and torrefaction. To include the varying method for the upstream processes, four different scenarios of torrefied biomass production are considered. The result of the analysis revealed that across all four scenarios, the torrefaction stage had a minimal contribution of 1-20% as compared with other life cycle stages. However, even with very optimistic assumptions among all scenarios, the result of the study shows a large energy deficit on the system due to the high energy consumption involved in the cultivation method and even in the drying process. To minimize energy consumption during the cultivation stage, solar lighting was highly recommended. The use of a solar-assisted drying was also advisable to lessen the energy consumption for the drying stage.
On the possibilities to reduce compression ignition engine emissions by controlling the reactivity of diesel-biofuel mixtures
Authors: Miron Lucian , Racovitza Alexandru , Chiriac Radu 
Published: April 2020

Abstract
In most European countries the use of different biodiesel fuels has been proved to be a sustainable method to reduce the pollutant emissions of the operating Diesel engines. An in-debt analysis of combustion characteristics is necessary to give a detailed perspective on the advantages of biodiesel use in compression ignition engines. Among all the essential parameters characterizing the compression ignition engine operation, the ignition delay is the most difficult to be estimated. This parameter offers the possibility to have more control over the combustion process inside the cylinder. This gives the ability to better quantify and ultimately to decrease the pollutant emission for this type of engine. An experimental study has been conducted on a tractor Diesel engine using different biofuel mixtures with 7% and 20% volumetric fractions of fatty acid methyl esters in Diesel fuel. No modifications were made to the fuel injection system in order to have a better image of the direct impact of biodiesel fuel on performance and emissions of the engine. The obtained results showed some reductions of total unburned hydrocarbons and nitrogen oxide emissions over the entire engine speed domain for both tested biodiesel fuels. The estimation of the ignition delay was experimentally carried out and correlated with the properties of the biodiesel fuel; a proper control of the combustion process by fuel reactivity ensured thus the mitigation of carbon monoxide, carbon dioxide and smoke. The link between the experimentally determined ignition delay, mainly it’s reduction, and fuel reactivity is what the present work tries to analyse. A better evaluation of the ignition delay parameter, shorter when using biodiesel mixtures, should lead to better control of combustion and further lowering the exhaust pollutant emissions, without major impact on engine performance. An in-debt analysis of the combustion process starting from the injection characteristics correlated with the fuel reactivity is necessary for shortening the ignition delay and reducing carbon dioxide emissions.