bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Low Cost Portable Hydro and Wind Power as Emergency Power Source
Authors: Supardi Agus , Raya Mukhlisin Yoga , Anwar rian Shaiful
Published: April 2021

Many outdoor activities are often carried out by the community. An emergency power is required to recharge the batteries of lighting equipment, communication equipment and other electronic equipment. Power bank as emergency power has a limited capacity so that it is not enough to meet the needs of power for several days. A portable power generation is needed to generate electricity using available natural resources such as running water or wind. The objective of this research is to develop a portable power generation system to meet the needs of electrical energy during outdoor activities. The portable power generation system consists of a small turbine, a small generator, and a battery charger. The prototype was tested in the laboratory and in the field. Tests showed the DC generator generated a voltage of 0.7 - 11.1 V when rotated at a speed of 117 - 1434 rpm. The step up converter produces a voltage of 2.2 - 15.74 V when the input voltage is 1.5 - 12 V. The boost module produces a voltage of 3.19 - 4.38 V when the input voltage is 3 - 12 V. The portable power generation system will generate electricity if the minimum speed of the running water is 4.8 m/s. When tested using wind power with speeds between 4.0 - 10.3 m/s, the portable power generation system produces a voltage of 1.4 - 9.3 V.
Use of zinc powder on Resistance Spot Welding on Mild Steel and aluminium
Authors: Hendrawan Muh Alfatih , Purboputro Pramuko Ilmu , Prima Aan
Published: April 2021

This study aims to determine mechanical properties of dissimilar metal resistance spot welding using zinc powder as an intermediate between 4000 series aluminium 1.2 mm thick with mild steel AISI 1008 thick 0.9 mm. The experiment was conducted on current parameters 7000 A, 8000 A, 9000 A, zinc powder mesh 200, and holding time 5 s. Tensile test showed that an optimal value on joining strength is at a current variation of 9000 A time 0.5 s of 1586.46 N. Additionally, Hardness testing in the weld metal area yields an optimal value at similar parameters as 232 HVN for aluminium and 210 HVN for Mild Steel. Based on Macro photo test results show that the current affects the width of the weld metal (nugget), the greater the current the wider the weld metal. Meanwhile, based on micro photos, there is a change of grain size on aluminium and mild steel welding.
Modular Mixer Machine Design for Liquid Fertilizer
Authors: Rochman Yuli Agusti , Wati Dwi Ana Ratna
Published: April 2021

Purpose: The design of the stirrer in making liquid organic fertilizer. Methodology: The TRIZ model is used in the design process. Results: The appropriate engineering characteristics to overcome the contradiction problem between the ability to rotate the mixer and the weight of the motor are the ‘force’ characteristic (parameter 10) and the ‘weight of stationary object’ characteristic (parameter 2). The solution is to move the weight of the motor on the object that will provide a ride. Applications/Originality/Value: Modular product development by applying the TRIZ concept has not been widely used. This paper will help position the TRIZ method in the design of modular products.
Modelling of Pedestrian Severity Factors in Traffic Accident in Depok
Authors: Widyaningrum Asri , Siregar Martha Leni
Published: April 2021

Purpose: Every country has a transportation system problem that can be solved in various different ways. But often, handling the transportation system is not accompanied by an increase in road facilities for vulnerable road users. One of them and the most often ignored is the provision of adequate facilities for pedestrians. Especially for big cities that are developing in Indonesia, such as satellite cities around Jakarta. Depok as satellite cities in Jakarta also have the same problem. As a result, the rapid population growth followed by vehicle growth and not being accompanied by good regional planning can harm the community, especially pedestrians. This study aims to modeling pedestrian severity factors in traffic accident in Depok. Methodology: The pedestrian severity observed was death, heavy injury and minor injury. Analysis carried out using multinomial logistic regression method so that later the opportunity model will be generated for the severity of traffic accidents based on prediction variables that have been tested. Results: The result, a statistically significant factor affecting the severity of pedestrian accident victims is the age of pedestrians and type of vehicle. Applications/Originality/Value: This study aims to determine the factors that cause pedestrian accidents in the city of Depok based on their severity. By knowing the factors that cause pedestrian accidents, it is hoped that the Depok city government can take further action to reduce the number of traffic accidents, especially those involving pedestrians as vulnerable road users.
Optimum amount of concrete objects of concrete asphalt layer using limestone aggregate
Authors: Candra A.I. , Winarto S. , Cahyono A.D. , Mahardana Z.B.
Published: April 2021

Concrete asphalt layer specimens are a mixture of coarse aggregate, fine aggregate, filler, and asphalt, which are crushed based on the number of collision plans. This study aims to determine the optimum number of collisions of concrete asphalt layer specimens using 100% coarse limestone aggregate against the Marshall Test. Marshall Tests produce Stability, Flow, and MQ values that are used to determine the age of the concrete asphalt layer plan. The stages of testing in this research were mixing the rough aggregate of limestone escaped sieve no. 3/4 - 8 mm or granular diameter between 0.5 cm - 2 cm, fine aggregate, filler, and asphalt. After mixing evenly and asphalt has covered all the aggregates, the mixture was inserted asphalt mold made of brass with a diameter of 100 mm height 65 mm. The next process is a compaction of the test specimen with five variations of collisions (50, 75, 100, 125, 150). After the test object is compacted, then a Marshall test is performed to find out the value of Stability, Flow, and MQ. The results of this study indicate that the optimum number of collisions is 100 times. This can be seen from the value of Stability: 1412 kg, Flow: 4.02 mm, and MQ: 351.2 kg/mm.
FMEA Approach to Risk Factors as a Factor in Implementing Green Supply Chain Management (Study in PT. Gresik Cipta Sejahtera)
Authors: Indrasari Lolyka Dewi , Vitasmoro Pamadya , Pariyanto Afiff Yudha Tri
Published: April 2021

A process that gives a negative impact on the environment is the existence of a production process which has the residual product in the form of non-biodegradable waste. Environmental impact studies do not only focus on waste but also its management, one ofthem is supply chain management in industry. It is important factors including the design of the product itself, selection of suppliers for the purchase of material products, manufacturing processes, how to deliver products to consumers and processing product remains to reduce environmental impact. PT. Gresik Cipta Sejahtera has a commodity of fertilizer products that are well known among the community of farmers and general users. So, this research’s aim is making the factors that cause danger in the company will be changed into factors that can help the creation of Green Supply Chain Management related to warehouse and transportation. The results show that the problems in the company which make problems for the company, can be analyzed Supply Chain Management to realize Green Supply Chain Management, which will bring a better influence for the company. The total problem is 16 already have a solution to be applied to the company in order to realize Green Supply Chain Management in the warehouse area and transportation equipment.
Mechanical and damping properties of composite rubber with waste crumb rubber tire and silica sand
Authors: Putra Emeraldo Gabriel , Priyosulistyo Henricus , Darmayadi Danna
Published: April 2021

The use of waste crumb rubber tire to reduce earthquakes impact on buildings is one of promising environmentally friendly solutions. Waste rubber tire will increase with the increasing number of vehicles. The purpose of this research is to study the mechanical and damping properties of waste rubber tire containing silica sand. Eleven different composites were produced with variation of the amount of waste rubber tire from 0, 25 and 50-per hundred rubber towards rubber compound based on their weight. The local silica sand consists of 10-phr, 20-phr, 30-phr, and 40-phr will be added on rubber compound containing 25 and 50-phr waste rubber tire respectively. Tensile strength, modulus of elasticity, shear modulus, and damping properties will be tested and researched. Composites of waste rubber tire with silica sand have lower tensile strength and modulus of elasticity with the addition of silica content. The shear modulus increased by loading silica sand and reached a maximum at filling of 40-phr. The damping properties also increased with the addition of silica sand and waste rubber tire, with the highest damping properties reached 10.40% on 40-phr silica sand and 25-phr waste rubber tire from the natural rubber damping properties of 3.10%. This study provides an overview of the effect of waste rubber tire and the interaction of silica sand on rubber properties experimentally.
Electromyography Gesture Identification Using CNN-RNN Neural Network for Controlling Quadcopters
Authors: Antonius Ray , Tjahyadi Hendra
Published: April 2021

Purpose: This paper presents a CNN-RNN neural network approach towards electromyography. Here the neural network is employed to identify different gestures from the reading of signals from human’s hand muscles. The identified gestures are then utilized to control a drone. Methodology: Implementation is made by using Myo, an 8-channel Electromyography (EMG) data acquisition device. 14000 datasets of 9 different gestures are collected and used to train the CNN-RNN models. The trained models are then tested on a drone using dronekit to translate the gestures to drone commands and send them from Python to the drone. Results: The results show that a CNN-RNN approach is very effective in identifying gestures from raw muscle data, resulting in an average of 96.60% positive identification for each gesture. The identified gesture shows an effective drone control from the simulated drone. Applications/Originality/Value: The high rate of positive identification opens the possibility to use a wearable device that is able to give the current state of the hand’s muscle tensions, translating them into a specific command to control devices or machines. With a rich information and real-time human control, it is expected that humans will experience a more intuitive approach towards devices or machines control.
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

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

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

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

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

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

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

Biscotti 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

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

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

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

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

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

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

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

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

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

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.
Early warrior authority
Authors: Wert Michael
Published: April 2021

This chapter describes the creation of warriors as an early status group. Minamoto Yoritomo won the Gempei War, an event that allowed him to create his own mini government in Kamakura, later referred to as the Kamakura shogunate. The chapter describes how some warriors gravitated to Kamakura, joined Yoritomo’s bureaucracy, and interacted with each other and the non-warrior nobles in Kyoto. It also highlights the important role of women in the formation of early warrior authority. Yoritomo died early on during this Kamakura Period (1185-1333) and several warrior families, along with their noble allies, struggled to dominate the warrior regime. The Hōjō emerged victorious and had to fight against the invading Mongols. In so doing, the Hōjō begin to dominate warriors throughout Japan. This chapter also introduces several sources of warrior “law” and conduct that show the influence of non-warrior elite culture on warrior culture and behaviour.
1. What is arbitration and where does it come from?
Authors: Schultz Thomas , Grant Thomas
Published: April 2021

This chapter traces the origins of arbitration. Arbitration initially developed in the absence of courts and later in opposition to courts, or at least as an alternative to them. The chapter then looks at the three episodes which illustrate the rise of modern arbitration. While arbitration takes many forms, all its forms share a core set of characteristics. Ultimately, arbitration is a procedure in which certain parties choose a decision-maker and grant the decision-maker the exclusive power to render a decision on a dispute between them—usually referred to as an arbitral award—following a procedure that complies with some standard of fairness also agreed by the parties.
6. Where is arbitration going?
Authors: Schultz Thomas , Grant Thomas
Published: April 2021

This chapter reflects on the future directions that arbitration might take. The privatization of justice through arbitration no doubt has advantages. However, privatized justice all too readily looks like justice for hire. So is privatized justice to be promoted, or should it be restrained? A fair reply is, it depends. The answers one gives in the debate over arbitration, as in so many debates over institutions that affect the public interest, are often shaped by one’s ideological starting point. Ultimately, arbitrators and the parties who call upon them should remain conscious of both arbitration’s promise and its limits, if they mean this noble institution well.
Motion and inertia
Authors: Wallace David
Published: April 2021

This chapter explores the question of what it means for something to move, and why physics cannot be done without an answer to that question. It does so mostly in the context of Newtonian physics, leaving considerations of the theory of relativity to the next chapter. We cannot simply define motion of one body as relative to another body if we want to do physics—we have to introduce the idea of a ‘rest frame’ that defines which bodies are at rest (Newton called this rest frame ‘absolute space’). But physics also satisfies the relativity principle—it is impossible to distinguish the rest frame from another frame moving at constant speed in that frame. So what physics really requires is not a preferred rest frame, but a family of inertial frames, all moving at uniform speeds relative to one another. The notion of ‘spacetime’ has been introduced as a way of understanding this family of inertial frames, but philosophers of physics disagree as to whether spacetime explains the nature of motion in physics, or merely codifies it. The chapter concludes by explaining how gravity can be thought of as a change in the structure of the inertial frames: though it was Einstein who first saw this clearly, it has nothing to do with relativity and makes sense even in Newtonian physics.
Reduction and irreversibility
Authors: Wallace David
Published: April 2021

This chapter considers philosophical issues that arise in statistical mechanics. Physics is not one theory but many, describing different bits of the world on different scales, and statistical mechanics is the field of physics that attempts to understand the relation between those descriptions. There are two alternative ways to think about statistical mechanics: either as a tool of inference, used to study complex systems in the face of our partial knowledge; or as a search for objectively true higher-level descriptions of those systems. On either conception, statistical mechanics needs to account for the emergence of irreversible, time-directed behaviour even though small-scale physics is reversible; it also needs to explain the role of probabilities, which are very widely used in statistical mechanics but have no uncontroversial interpretation.
Interpreting the quantum
Authors: Wallace David
Published: April 2021

This chapter surveys various proposals to interpret—that is, make sense of—quantum mechanics. We could attempt to think of quantum mechanics in purely instrumentalist terms, as an algorithm to predict observed experimental results. But this fits badly with scientific practice and is probably not viable. We could attempt to modify quantum mechanics itself to resolve the paradoxes, and there are some simple models that attempt to do that: some are ‘hidden-variable’ theories that add extra properties to the theory, some are ‘dynamical-collapse’ theories that modify the theory’s equations. But none of these models succeed in reproducing quantum theory’s predictions outside a relatively narrow range of applications. Or we could try to take the apparent indefiniteness of quantum mechanics literally, and interpret it as a theory of many parallel worlds. The correct interpretation of quantum mechanics remains controversial, but the search for understanding and interpretation of the theory has led to very substantial scientific results and is likely to lead to more.
Sex-specific differences in Juniperus communis: essential oil yield, growth-defence conflict and population sex ratio
Authors: Markó Gábor , Németh István , Gyuricza Veronika , Altbäcker Vilmos
Published: April 2021

In plants, biomass and nutrient allocation often generate trade-offs between the different biochemical pathways conflicting the utilization of the common source among growth, reproduction and chemical defence. However, in dioecious plant species, these trade-off patterns could appear as a more contrasted problem between males and females due to the dissimilar reproduction investment. Generally, the growth ratio is higher in males than females, while females have a stronger defence than males. To understand the possible role of the sex-specific dissimilarities within the growth-defence conflict framework, we investigated the possible causes of the high variance of the essential oil yield in a dioecious evergreen species, Juniperus communis. Specifically, we tested the correlations between the essential oil yield with other individual-specific traits (e.g. sex, age), the presence of the growth-defence trade-off, and the differential growth and survival patterns between males and females through an extensive field survey with sample collection in three natural populations (Kiskunság National Park, Hungary). The individual-specific essential oil yield was also measured and served as a proxy to describe the degree of chemical defence. We found that the essential oil yield showed strong and consistent sex-specific patterns decreasing with age in adults. Contrary to the predictions, the males showed a consistently higher yield than the females. We also observed a growth-defence trade-off in males but not in females. Consistently with the growth-defence conflict hypothesis, the populations’ sex ratio was male-biased, and this pattern was more evident with ageing modifying the demographic structure due to the sexually dissimilar lifespan. Our juniper study revealed a contrasting and unique essential oil accumulation driven by the complex allocation trade-off mechanisms within individuals, which could be a flexible and adaptive defence response against the increasing biotic and abiotic environmental stresses exacerbated under global climate change.
Plures leges faciunt arbitrum
Authors: Ferrari Franco
Published: April 2021

The article analyses the continuing importance of the law of the seat, while at the same time showing that the law of the seat cannot be the only one to impose itself on any given arbitration.
Changing Mandible Contour Using Computer Designed/Computer Manufactured Alloplastic Implants
Authors: Straughan David M , Yaremchuk Michael J
Published: April 2021

Background

The shape of the mandible is the fundamental determinant of the appearance and sexual dimorphism of the lower one-third of the face. Utilization of computer-aided design/computer-aided manufactured (CAD/CAM) alloplastic implants provides unparalleled planning and sophistication in the correction of skeletal deficiencies, irregularities, and asymmetry.

Objectives

This study presented the rationale, indications, techniques, and results of the senior author’s (M.J.Y.) 15-year experience employing CAD/CAM alloplastic implants to correct deficiencies and asymmetries of the mandible.

Methods

A retrospective review of a prospectively maintained database was reviewed of all patients who underwent aesthetic augmentation of the mandible employing CAD/CAM alloplastic implants by the senior author.

Results

Over a 15-year period, 123 patients underwent mandibular augmentation utilizing CAD/CAM alloplastic implants. The majority of patients were men (76.4%) with an average age of 31 years (range, 24-63 years). All implants were bilateral. Complications included infection requiring implant removal (2.4%) and patient dissatisfaction resulting in either implant revision (4.1%) or implant removal (2.4%).

Conclusions

As described here, CAD/CAM alloplastic implants are an effective modality to augment aesthetic mandible contour deficiencies.

Level of Evidence: 4
Does Surgeon Gender Matter for Aesthetic Patients?
Authors: Hancock Ellen A , Hancock Kevin J , Wijay Nandhika , Andry Danielle
Published: April 2021

Background

Plastic surgery patients have expectations for an ideal practice to visit. However, patients’ preferences regarding their plastic surgeon are still being described.

Objectives

The aim of this study was to investigate if elective cosmetic plastic surgery patients exhibit gender preference in their plastic surgeon when making online inquiries.

Methods

A retrospective, single-practice review of all online inquiries for elective plastic surgery and nonsurgical injectable treatment from June 2019 to June 2020 was performed. The study was based on a private practice located in Houston, TX. The practice surgeons were a married couple, 1 female and 1 male, with identical training, age, and post-residency experience. Patients submitted an online inquiry for their procedure of interest and surgeon preference via the practice website.

Results

The private practice received 873 online inquiries during the year-long study period. The majority of patients were female, 855 (97.9%), and the remaining 18 (2.1%) were male. Of the female patients, 476 (55.7%) preferred a female surgeon and 138 (16.1%) preferred a male surgeon; 241 (28.2%) female patients expressed no surgeon preference. Regardless of surgeon preference, the majority of procedures inquired about were breast and body contouring.

Conclusions

This cohort of female patients prefers the female surgeon for breast procedures or multiple procedures involving the breast, and the male surgeon for injectable procedures and facial procedures. There is no preference for the male or female surgeon for body procedures. Female plastic surgery patients may be influenced by surgeon gender in choosing their surgeon, depending on their surgery of interest.
Mechanisms underlying enhanced IgA production in Peyer's patch cells by membrane vesicles derived from Lactobacillus sakei
Authors: Miyoshi Yuki , Saika Azusa , Nagatake Takahiro , Matsunaga Ayu , Kunisawa Jun , Katakura Yoshio , Yamasaki-Yashiki Shino
Published: April 2021

We analyzed the mechanisms underlying enhanced IgA production in the cells of Peyer's patch cells via membrane vesicles derived from Lactobacillus sakei subsp. sakei NBRC 15893. Depletion of CD11c+ cells from Peyer's patch cells suppressed the enhanced IgA production mediated by membrane vesicles. Meanwhile, the stimulation of bone-marrow–derived dendritic cells with membrane vesicles increased gene expression of inducible nitric oxide synthase, retinaldehyde dehydrogenase 2, and several inflammatory cytokines. The production of nitric oxide and interleukin (IL)-6 by membrane vesicle stimulation was induced via Toll-like receptor 2 on bone marrow–derived dendritic cells. Inhibition of inducible nitric oxide synthase and retinaldehyde dehydrogenase 2, as well as the neutralization of IL-6 in Peyer's patch cells, suppressed the enhanced IgA production by membrane vesicle stimulation. Hence, nitric oxide, retinoic acid, and IL-6 induced by membrane vesicles play crucial roles in the enhanced IgA production elicited by membrane vesicles in Peyer's patch cells.