bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Road Shoulder Width and Speed Bump Dimensions on Motorbike Speed Reduction
Authors: Handayani Dewi , Dinasty Purnomoasri RA , Syafi’i  , Mahmudah AMH 
Published: April 2021

Abstract
This study aims to obtain the characteristics of a decrease in motorbike speed before speed bump and a model of the relationship between a decrease in motorbike speed, dimensions of the speed bump and the width of the shoulders on local roads in residential areas. Data collection technique with artificial lines from vehicle recording before passing speed bumps using a Yi-4k action camera. Motorcycle speed data is used to analyse the decrease in speed to be made a mathematical model of the relationship of motorcycle speed, dimensions of speed bumps, and road shoulder width. It can be concluded that the speed bump can reduce the speed up to 72.18% from the average normal speed of the road under study, with decelerate moving from 0.38 m/s2 to 0.30 m/s2 at a distance of 16 meters before the speed bumps arrive at over speed bump. The model chosen for the relationship of decreasing speed, dimensions of speed bump and shoulder width at a distance of 8 meters before speed bump (Y1) is Y1 = 13.615–0.090X
2 + 0.038X
3, while at a distance of 16 meters before speed bump (Y2), chosen equation Y2 = 15.403–0.639X
1 + 0.042X
3, R2 = 0.976, with X
1 (High Speed bumps), X
2 (Speed bumps width), X
3 (Width of the shoulder), Y
1 (Varea 8 m), Y
2 (Yard) Varea 16 m).
Effect of Black Carbon Composition on Hardness, Strength, Wear Resistance and Grip Coefficient of Tire Compound
Authors: Purboputro Pramuko Ilmu , Darmawan Agung Setyo , Febriantoko Bambang Waluyo 
Published: April 2021

Abstract

Purpose: The purpose of this work was to investigate the effect of arrow pattern tire compound on hardness, wear resistance and grip coefficient in dry and wet operation conditions. Methodology: The mixing compound would be consist of Rubber Smoked Sheet (RSS), Styrene Butadiene Rubber (SBR), Black Carbon, Paraffin oil, ZnO, Stearic Acid, Paraffin wax, Epoxy and Sulphur. The compound is mixed and heated to 100°C. After being cooled it is then conducted hardness test, performed wear test and tested for friction. Results: The hardness and the tensile strength of the tire compound increase with increasing black carbon composition. While the wear of the tire compound decrease with increasing black carbon composition. There were no significant differences of grip coefficient when black carbon increased. However, grip coefficient will decrease by 12% when operating conditions change from dry asphalt track to wet asphalt track. Applications/Originality/Value: The life of tire compound usage is increased by the addition of black carbon particles.
Effectiveness of stormwater facilities to reduce surface runoff and peak flow at JIExpo Kemayoran using Site Evaluation Tools (SET)
Authors: Hidayat Ryan , Sutjiningsih Dwita , Anggraheni Evi 
Published: April 2021

Abstract
The high rate of urbanization is one of the problems that has occurred in Jakarta as capital of Indonesia. The implication is the change in land use from pervious cover to impervious cover which have an impact on increasing stormwater runoff. Jakarta International Expo (JIExpo) is one of commercial complex in Central Jakarta. The complex covered area around 43.59 hectares and highly impervious (approximately 84 percent). This study simulating two stormwater facilities green roofs and permeable pavements, with total area to be converted aproximately 9.21 hectares (21 percent). The modelling run using Site Evaluation Tools (SET) Microsoft Excels spreadsheet to show the both of stormwater facilities effect on the surface runoff and peak flow. The results indicated that the techniques can be used to reduce runoff volume and peak flow. Per unit area, the green roofs better than permeable pavements at reducing the surface runoff evaporation and evapotranspiration. However, permeable pavements were better than green roofs at increasing infiltration. The simulation shows that by the combination of green roofs and porous pavement, the surface runoff can reduced by approximately 57%, the runoff volume can reduced by approximately 1.20% for 2-year daily rainfall, and the peak flow can reduced by approximately 50%. Overall, the SET is easy to use and useful for evaluating the effects of stormwater facilities.
Five years of variability in the global carbon cycle: comparing an estimate from the Orbiting Carbon Observatory-2 and process-based models
Authors: Chen Zichong , Huntzinger Deborah N , Liu Junjie , Piao Shilong , Wang Xuhui , Sitch Stephen , Friedlingstein Pierre , Anthoni Peter , Arneth Almut , Bastrikov Vladislav , Goll Daniel S , Haverd Vanessa , Jain Atul K , Joetzjer Emilie , Kato Etsushi , Lienert Sebastian , Lombardozzi Danica L , McGuire Patrick C , Melton Joe R , Nabel Julia E M S , Pongratz Julia , Poulter Benjamin , Tian Hanqin , Wiltshire Andrew J , Zaehle Sönke , Miller Scot M 
Published: April 2021

Abstract
Year-to-year variability in CO2 fluxes can yield insight into climate-carbon cycle relationships, a fundamental yet uncertain aspect of the terrestrial carbon cycle. In this study, we use global observations from NASA’s Orbiting Carbon Observatory-2 (OCO-2) satellite for years 2015–2019 and a geostatistical inverse model to evaluate 5 years of interannual variability (IAV) in CO2 fluxes and its relationships with environmental drivers. OCO-2 launched in late 2014, and we specifically evaluate IAV during the time period when OCO-2 observations are available. We then compare inferences from OCO-2 with state-of-the-art process-based models (terrestrial biosphere model, TBMs). Results from OCO-2 suggest that the tropical grasslands biome (including grasslands, savanna, and agricultural lands within the tropics) makes contributions to global IAV during the 5 year study period that are comparable to tropical forests, a result that differs from a majority of TBMs. Furthermore, existing studies disagree on the environmental variables that drive IAV during this time period, and the analysis using OCO-2 suggests that both temperature and precipitation make comparable contributions. TBMs, by contrast, tend to estimate larger IAV during this time and usually estimate larger relative contributions from the extra-tropics. With that said, TBMs show little consensus on both the magnitude and the contributions of different regions to IAV. We further find that TBMs show a wide range of responses on the relationships of CO2 fluxes with annual anomalies in temperature and precipitation, and these relationships across most of the TBMs have a larger magnitude than inferred from OCO-2. Overall, the findings of this study highlight large uncertainties in process-based estimates of IAV during recent years and provide an avenue for evaluating these processes against inferences from OCO-2.
Assessment of the Efficiency of Using Modis MCD43A4 in Mapping of Rice Planting Calendar in the Mekong Delta
Authors: Diem P K , Diem N K , Hung H V 
Published: April 2021

Abstract
This study used 487 MODIS MCD43A4 images, 1-day resolution, 500-meter spatial resolution to evaluate the efficiency of using the MODIS image series in monitoring the rice planting calendar in the Mekong Delta in 2019. The Savitzky-Golay filter method was applied to eliminate noise and smooth the time series of NDVI imagery. The rice plating date was then determined using TIMESAT software based on the threshold of increasing NDVI to 20% of the amplitude each season. The reliability of the model for mapping rice planting calendar was evaluated by compared to field data and local statistics. The results showed that the series of MODIS MCD43A4 images was used effectively in map of rice planting calendar for the Winter-Spring season, with area error was less than 10% and different of sowing date was less than 15 days (N = 21, MAE = 15 days, RMSE = 18 days). However, the series of MCD43A4 images was limited in monitoring the rice crop calendar of the other two remaining seasons (Summer-Autumn and Autumn-Winter) with an area error was greater than 30% and a higher difference in the time of sowing compared to the Winter-Spring season, especially in the Autumn-Winter season (N = 20, MAE = 22 days, RMSE = 23 days). The above results showed that the MODIS image series was effectively used in the dry season (Winter-Spring) and limited in the rainy season due to the influence of weather and clouds. Further studies combining the use of other types of satellite images or methods to replace cloud-affected pixels needed to be taken into consideration.
Urbanization and Sustainable Growth of Urban Kano, Nigeria
Authors: Unah  , Okopi Mathew 
Published: April 2021

Abstract
Kano state of Northern Nigeria is the fastest growing city in the sub-Sahara Africa. Having undergone massive transformations in the past century has been characterized by urbanization of sustainable rapid developmental growth. The full impact of urbanization pressures has led to the rapid pace of globalization and economic restructuring and infrastructural development of Kano dated from the colonial era. The paper seeks to highlight and undertakes a descriptive analysis of underlying issues associated with the practice of sustainable urbanization challenges facing Kano, particularly the promotion of growth management within the fast growing City which is the commercial hub of the Northern Nigeria. The qualitative nature of the paper was a critical literature review of relevant materials. The paper seeks to provide an insight into sustainable paradigm, and urban growth development of Metropolis Kano-city. The finding shows that sustainable urbanization has been a key factor in the adoption of urban growth development and expansion of Kano environs. Findings from the study reveal that physical development plans for the urban growth areas have been very pre-colonial dated and developed in harmony with the urban development which is mostly characterized by infrastructure pace.
Nutritional Value and Consumer Acceptability of Biscotti Made from Rambutan Seed Flour
Authors: Miranti Mauren Gita , Wahini Meda 
Published: April 2021

AbstractBiscotti is small rectangular bar biscuits containing nuts, twice-baked, oblong-shaped, dry, crunchy, and made from flour, sugar, eggs, pine nuts and almonds. Generally, the flour used is derived from wheat. However, the flour can also be made from rambutan seed that have nutritional value which is good for health. The objectives of this study were to: 1) find the best formula from rambutan seed flour biscotti; 2) know the nutritional value of the selected formula; and 3) know the consumer acceptability. This research was experiment with one factor model in different propotional levels (40; 60; 80; 100), and it analyzed using chemical test and descriptive analysis of sensory quality. The nutritional value of biscotti obtained were compared with nutritional value of rambutan seed flour. These include energy, protein, carbohidrates, fat, ash, Vit C, fiber, and antioksidant. The result showed that 1) the best formula on sensory quality of rambutan seed flour biscotti is resulting from more than a half rambutan seed flour subtitutions; 2) the selected formula contain energy, protein, carbohidrates, fat, ash, Vit C, fiber, and antioxidant; and 3) the consumer acceptability of biscottti from the best formula namely: odor, texture, crunchiness, taste and overall acceptability. This study indicate that 60-80 rambutan seed flour can be utilized as potential raw material food for biscotti.
Investigation on Interaction between Geometry and Performance and Design of S-CO2 Radial Inflow Turbine’ s Vaneless Inlet Volute
Authors: Zhu Chang , Shao Wen-Yang , Ma Zi-Yue , Lv Guo-Chuan , Wang Xiao-Fang 
Published: April 2021

Abstract
The inlet volute is one of the key components that guide the working fluid into the radial inflow turbine. It has a significant effect on the performance of the radial inflow turbine. The conventional design criteria for the vaneless inlet volute mainly focuses on the ideal gas, which does not apply to real gas cases, such as supercritical carbon dioxide(S-CO2). In this paper, an MW-class S-CO2 radial inflow turbine is studied. Firstly, the inlet volute design of the radial inflow turbine with a vaned stator is completed, and the flow in the whole machine is calculated using CFD simulations. Then, based on the inlet boundary conditions of the impellers, the vaneless inlet volute with different throat areas and cross-sectional area distributions are investigated. The results indicate that the size of the counter rotating vortexes in the vaneless inlet volute increases with the throat area increasing, and is also influenced apparently by the cross-sectional area distribution. The volute throat area has little effect on the circumferential distribution of the outlet airflow angle but changes the average value of the airflow angle. The cross-sectional area distribution of the volute influences the circumferential distribution of the outlet flow angle. The result indicates that volute with a small-scale convex profile has a uniform outlet flow field. Compared to the turbine with the vaned stator, the radial dimension of the vaneless volute turbine obtained in the final design is significantly reduced, and the total-total efficiency at the design point is 85.62%, which meets the design requirements. Moreover, it also has good performance at off-design operating conditions.
Research on the Adjustable Guide Vane in a Compressor Sector Cascade
Authors: Xu W F , Sun P , Yang G G 
Published: April 2021

Abstract
In order to simulate the inlet flow angle and Mach number of the tested blade, a row of guide vanes is set before the tested blade during the sector cascade experiment. In this paper, a kind of adjustable guide vane (AGV) is designed, which can rotate continuously and change the inlet flow angle of the tested blade conveniently and quickly. The variation rule of the clearance between the AGV and the end wall is introduced. The influence of the clearance on the flow field structure under different Mach number and incidence angle is studied by numerical and experimental methods. It is found that the clearance of the leading edge is small at the top and the root, and the leakage vortex is mixed with the passage vortex. The interaction between the leakage vortex and the passage vortex in the trailing edge results in the decrease of Mach number and the increase of flow angle at the AGV outlet. The clearance has little effect on the span of 20% - 80%. At the same incidence angle condition, with the increase of Mach number, the influence range of leakage vortex is expanded, and the variation magnitude of flow angle and Mach number at the top and root position is increased; At the same Mach number condition, with the decrease of the AGV rotation angle from positive to negative, the top clearance is increased gradually, and the root clearance is decreased gradually. The separation range at the top is expanded gradually, which results in the variation magnitude of flow angle and Mach number is increased, but the effect is opposite at the root of the AGV.
Research the Influence of Hydraulic Model on Vibration of Pump
Authors: Zhao Feng , Li He , Liu Duo , Fu Jun 
Published: April 2021

Abstract
In this paper, the cooling water pump of centrifugal equipment is taken as the research object in ship system. The pump set is normally open. And, it is also one of the main vibration sources of ship. On the premise of meeting the requirement of hydraulic performance parameters, several different hydraulic model prototypes of this pump set are manufactured. On the same test bench, the vibration tests of this pump show that the measured values are quite different. Fluid software is used to analyse these hydraulic models under the same boundary conditions. It is found that there are obvious differences in hydraulic fluctuations and fluid vortices among impeller passage, vortex chamber, inlet and outlet passages. In order to verify the inference, vibration test and analysis are carried out on the whole pump set and the foots of installation. The corresponding relationship was found out between the fluid fluctuation of hydraulic components and the vibration characteristics. Based on the corresponding relationship, the current hydraulic model of pump is optimized and improved. The parameters of hydraulic model which can affect the vibration sensitivity of pump are optimized. Finally, the experimental results prove that this method can reduce the vibration effectively.
A Study of Stall Condition of a Centrifugal Compressor based on CFD and Experimental Methods
Authors: Wang R. , Wang H. L. , Yang S. H. , Tan J. J. , Jiang S. , Ren J.Q. 
Published: April 2021

Abstract
The stall point of a centrifugal compressor is obtained by CFD method and FFT method, and an experiment in the stall point is carried out. Firstly, the curves of the compressor efficiency and total pressure ratio with flow rate are obtained by the steady CFD analysis. Secondly, according to the curves, the unsteady CFD analysis and frequency signal analysis are carried out at the operation points where stall may occur. Then the stall point of the compressor is obtained. On the basis of the results of numerical analysis, the model machine is used to carry out the test. By comparing the results of the numerical method and the experimental method, the stall is identified at the similar operation point, which proves the effectiveness of the prediction method in this paper.
Investigation of the shell-side flow in a shell-and-tube exchanger with impingement plate
Authors: Wang Yi , Qin Guoliang , Zhang Yong , Yang Shuhua , Sun Yuying , Cui Qin , Jia Cheng 
Published: April 2021

Abstract
For studying the influence of impingement plates on the fluid flow within the shell-side of the shell-and-tube heat exchanger, two-dimensional numerical simulation is carried out using the Fluent software. The different distances between the impingement plate and the tube bundle are taken into consideration. Meanwhile the research investigates the flow field of the non-perforated impingement plate and the perforated impingement plates with various hole diameters. The results show that the fluid behind the non-perforated impingement plate contacts the tube insufficiently. The farther the distance between the non-perforated impingement plate and the tube bundle is, the more tubes contact with the fluid poorly. The flow field behind the perforated impingement plates is more uniform. The protective effect from flow impacting for impingement plates is positive. The perforated impingement plates are recommended in the engineering design of the shell-and-tube heat exchanger.
Measurements and Data Analysis Review of Laminar Burning Velocity and Flame Speed for Biofuel/Air Mixtures
Authors: Abdulraheem Ahmed Abdulameer , Saleh Adel Mahmood , Shahad Haroun AK 
Published: April 2021

Abstract
Precise measurement and prediction of flame speed and laminar burning velocity are essential for premixed combustion properties characterization, turbulent combustion models validation, progress, and validation of chemical kinetic models. Besides, the problem of lack of fossil fuel, planet pollution, and production of several fuel alternatives led researchers to reexamine the process of combustion and optimize fuel consumption. So, it would be necessary to know the change of laminar burning velocity and flame speed with thermodynamic conditions to understand the impression of practical applications in all combustion systems as working pressures and temperatures are extensively higher than the atmospheric conditions. Several investigations work regarding flame speed and laminar burning velocity had been achieved. However, a detailed literature review of methods and techniques used to measure these two parameters and the effect of operating factors for different fuels focusing on biofuels is presented in this paper for ease of reviewing.
Contact line dynamics of gravity driven spreading of liquids
Authors: Mohammad Karim Alireza , Fujii Keita , Kavehpour H Pirouz 
Published: April 2021

Abstract
The spreading dynamics of the gravity-driven liquid motion on an inclined solid surface was studied by considering two fundamental physical models: the molecular kinetic theory and the hydrodynamic theory (HDT). The molecular kinetic theory is the most appropriate model to describe the gravity driven spreading mechanism investigated in this study. The gravity driven spreading which is one form of the forced spreading mechanism was compared with the spontaneous spreading for the same liquid/solid system from previous study by Mohammad Karim et al (2016 Langmuir
32 10153). Unlike the gravity driven spreading, the HDT was appropriate model to define the spontaneous spreading. This finding reveals the importance of the mechanism of spreading which are the forced and the spontaneous on the suitability of the physical model such as the molecular kinetic theory and the HDT to describe the spreading dynamics.
Preparation and properties of MoS2 modified polydimethylsiloxane/monomer casting nylon
Authors: Shangguan Jinfei , Song Ling , Lang Feng , Yang Haiyang , Li Duxin , Wang Jin , Jiang Qibin , You Yilan 
Published: April 2021

Abstract
MoS2 reinforced PDMS/MC nylon composites had been fabricated by in situ polymerization to further enhance the comprehensive properties of nylon material. Polydimethylsiloxane was pre-sythesized as the activator of the system and MoS2 was compounded as the wear-resisting agent. The thermal stability, mechanical properties, friction and wear properties of composites with different MoS2 contents were tested. The results showed that the crystallization and thermal stability of nylon matrix were increased with the addition of MoS2, while the tensile strength and impact strength were slightly reduced. The composites finally presented excellent friction properties with 3 wt% MoS2, whose friction coefficient was reduced to 0.75 (18.48% decrease) corresponding to the wear rate of 0.4145 × 10−8 g Nm−1.
Complete parameter inference for GW150914 using deep learning
Authors: Green Stephen R , Gair Jonathan 
Published: April 2021

Abstract
The LIGO and Virgo gravitational-wave observatories have detected many exciting events over the past 5 years. To infer the system parameters, iterative sampling algorithms such as MCMC are typically used with Bayes’ theorem to obtain posterior samples—by repeatedly generating waveforms and comparing to measured strain data. However, as the rate of detections grows with detector sensitivity, this poses a growing computational challenge. To confront this challenge, as well as that of fast multimessenger alerts, in this study we apply deep learning to learn non-iterative surrogate models for the Bayesian posterior. We train a neural-network conditional density estimator to model posterior probability distributions over the full 15-dimensional space of binary black hole system parameters, given detector strain data from multiple detectors. We use the method of normalizing flows—specifically, a neural spline flow—which allows for rapid sampling and density estimation. Training the network is likelihood-free, requiring samples from the data generative process, but no likelihood evaluations. Through training, the network learns a global set of posteriors: it can generate thousands of independent posterior samples per second for any strain data consistent with the training distribution. We demonstrate our method by performing inference on GW150914, and obtain results in close agreement with standard techniques.
Becoming those who served
Authors: Wert Michael 
Published: April 2021

Abstract
This chapter defines what is meant by “warrior” in early Japanese history, describes the different possible origins of the warrior class, and the interaction between elite warrior-nobles and non-warrior nobility. In this early period, from prehistory to the ninth century, there was no well-defined warrior class or status group. Warriors across Japan did not think of themselves as belonging to a single group, nor did they have much political power except for the warrior-noble elite, like the Taira and Minamoto clans.