bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global rangeland production systems and livelihoods at threat under climate change and variability
Authors: Godde C M , Boone R B , Ash A J , Waha K , Sloat L L , Thornton P K , Herrero M 
Published: February 2020

Abstract
Rangelands are one of the Earth’s major ice-free land cover types. They provide food and support livelihoods for millions of people in addition to delivering important ecosystems services. However, rangelands are at threat from climate change, although the extent and magnitude of the potential impacts are poorly understood. Any declines in vegetation biomass and fluctuations in grazing availability would be of concern for food production and ecosystem integrity and functionality. In this study, we use a global rangeland model in combination with livestock and socio-economic datasets to identify where and to what extent rangeland systems may be at climatic risk. Overall, mean herbaceous biomass is projected to decrease across global rangelands between 2000 and 2050 under RCP 8.5 (−4.7%), while inter- (year-to-year) and intra- (month-to-month) annual variabilities are projected to increase (+21.3% and +8.2%, respectively). These averaged global estimates mask large spatial heterogeneities, with 74% of global rangeland area projected to experience a decline in mean biomass, 64% an increase in inter-annual variability and 54% an increase in intra-annual variability. Half of global rangeland areas are projected to experience simultaneously a decrease in mean biomass and an increase in inter-annual variability—vegetation trends both potentially harmful for livestock production. These regions include notably the Sahel, Australia, Mongolia, China, Uzbekistan and Turkmenistan and support 376 million people and 174 million ruminant Tropical Livestock Units. Additionally, the rangeland communities currently the most vulnerable (here, with the lowest livestock productivities and economic development levels and with the highest projected increases in human population densities) are projected to also experience the most damaging vegetation trends for livestock production. Although the capacity of rangeland systems to adapt is highly complex, analyses such as these generate some of the information required to inform options to facilitate pastoral system mitigation and adaptation strategies under climate change.
Region Adaptability of XiGuan Grand House and Its Value to Ecological Architecture Design
Authors: Jue Chen , Chen Wang 
Published: February 2020

Abstract
In the late Qing Dynasty, XiGuan Grand House appeared as the large vernacular dwellings architecture. The so – called region adaptability is formed for the local vernacular dwellings architectures need to adapt to the changes of the local nature, society and humanism and continue the evolving way of Original Ecological architecture. This paper is divided into three parts. In the first part, the evolving process about XiGuan Grand House is analyzed; the second part discusses the relationship between the region adaptability and the architectural evolution; the last part studies the region adaptability of XiGuan Grand House to obtain its value to Ecological Architecture Design.
Impact of cities adaptation to climate change on water resources management on the example of selected cities of the Silesian Agglomeration
Authors: Gałas S , Gorgon J , Gałas A 
Published: February 2020

Abstract
Climate change and the resulting threats create a new challenge for local authorities and residents of cities. The nationwide Project addressed for biggest Polish cities assessed their sensitivity and counteracting capabilities in selected urban areas. Within the Project various actions were proposed. To some extent, the implementation of these activities may, however, threaten the water resources. The paper presents risk assessment and shows the possibilities of rational management of water resources in selected cities of Upper Silesia.
Stress Analysis of Surrounding Rock of Rectangular Pipe Gallery in Mountain City
Authors: Wang Yuanqing , Jin Xiaoguang , Yang Qingting 
Published: February 2020

Abstract
In this paper, the basic methods and principles of complex variable function to solve the excavation problem of caverns in single connected domain are studied. Based on the basic principle of conformal transformation and the engineering practicability, the problem of excavating rectangular section single warehouse pipe gallery in a single rock stratum is simplified as a semi-infinite plane rectangular hole problem. The rectangular hole problem is transformed into an equivalent circular hole by conformal transformation. A simplified calculation model of the extruding rectangle comprehensive pipe gallery is proposed and its surrounding rock stress calculation formula is deduced. Combined with the example of mountainous city comprehensive pipe gallery project, Theoretical calculation and numerical simulation show that the surrounding rock stress of the comprehensive pipe gallery is close, which verifies the applicability of the simplified formula. The structural design and construction design of rectangular integrated pipe gallery provide theoretical support. Comparing the stress of surrounding rock of different width pipe gallery, it is found that the stress concentration degree at the top corner of the rectangular pipe gallery increases with the increase of the width of the pipe gallery. The width of the excavation of the rectangular pipe gallery must be strictly controlled during construction.
Damage State Assessment of a Pre-Stress Concrete Girder (PSCG) Bridge using Non Linear Analysis for Real-time Structural Health Monitoring
Authors: Montes K M , Embalzado K A , Sales N M , Sayno A J , Payawal J M , Uy F A A 
Published: February 2020

Abstract
Philippines is located in the pacific ring of fire, which indicates that seismic movement is frequently happening. West valley fault line located in the central Luzon might move due to its 400 to 500-year recurrence, and the last recorded movement was on 1958. According to MMIERS, the movement of west valley fault with 7.2 magnitude earthquake can cause one of the biggest devastation in Metro Manila. In preparation for that, this study aims to assess the vulnerability of a pre-stress bridge against seismic movement by the aid of USHER technology. The USHER system includes structural assessment, remote sensing, and real time monitoring through the portal. This study will focus on the structural assessment of the bridge, which identify the acceleration limits that the bridge can endure to interpret different level of damage. As a result, by 10% of probability of exceedance from SEAOC using the moderate damage fragility curve, the results in three directions are 0.37641g in longitudinal axis, 0.366025g in transverse axis, and 0.394498g in the vertical direction. The most critical is in the transverse direction, which can produce a maximum of 67mm displacement of the bridge in the inelastic stage. In validation through the sensor, which has a reading from the smart bridge project, the maximum acceleration recorded was 0.138g. This concludes that the bridge is safe and no retrofitting works is need.
Concept Design of a Single-Aisle Aircraft Spoiler by Topology Optimization
Authors: Purith P , Kittikorn C , Pakpong J , Mezeix L 
Published: February 2020

Abstract
Sandwich are widely used in the aerospace as flaps, spoiler, cabin floor or rotor where high flexural rigidity is required. Sandwich structures consist in a thick core material as honeycomb bonded with thin skins as carbon fibres. When the core material contains closed cells, water ingression must be considered. This water ingression may significantly increase the weight of the core and can induce damage. In this project, new spoiler design is proposed based on reinforced stiffeners in order to avoid the use of honeycomb. In a first step model is built and validated on current spoiler. Then, topology tool is used to locate the stiffeners. Finally, GFEM is performed to propose a first rough plies optimization under static analysis.
Study of Failure Analysis of a Fracture Crankshaft Pulley Used on a Truck Engine
Authors: Husaini  , Putra T E , Novriandika S 
Published: February 2020

Abstract
A pulley is a mechanism consisting of a wheel, with a groove between its two edges, which is fastened to a shaft. The belt usually passes along the groove of the pulley to give it the power of movement and rotation. In December 2016 there was a case of failure of the crankshaft pulley in a truck. This study aims to investigate the causes of fracture. Therefore, it was necessary to perform a failure analysis. Investigation methods included visual examination, scanning electron microscope analysis, chemical analysis of the material and mechanical tests. A finite element analysis (FEA) was also performed to quantify the stress intensity factor (KI) distribution in the crankshaft pulley that is near the crack tip. From the finite element analysis, it was found that K1
was greater than the fracture toughness (KIC) of the material. Therefore, the propagation of crack occurs from the initial crack until final failure.
Multi-Directional Forced Convection Kiln Oven Drying System for Bamboo Culms
Authors: Atienza A H , Dela Peña R , Eroles R , Fandiñola E 
Published: February 2020

Abstract
The bamboo industry in the Philippines is at the commencement of its development in terms of co-existing with the current technology. The study aims to develop and improve the processing of bamboo, specifically its drying process. The traditional drying process in the Philippines is sun drying which is a primitive way of drying the bamboo. The drying process presented in this study is the forced convection kiln oven drying. It offers fast drying time and allows the bamboo culm to be enclosed on a system to prevent dirt or other contaminants to accumulate on the culm. The prototype is composed of a blower that would exhibit the forced convection; a base considered to be the system for the bamboo to dry and a heating element that would induce the heat necessary for the drying. The heating source is an electrical component that requires electricity from an AC power source. In order to test the prototype, a fresh bamboo is to be dried inside the system and its moisture content would be monitored with respect to time. The result of the test would provide for the conclusion of the efficiency of the dryer to reduce the moisture content of the bamboo.
Synthesis and Characterization of Monoclinic Gallium Oxide Nanomaterials for High-Concentration Ethanol Vapor Detection
Authors: dela Torre H M B , Santos G N C 
Published: February 2020

Abstract
This study was conducted to synthesize Gallium Oxide nanomaterials from its bulk form using a low-cost and repeatable method and investigate on its potential as sensing element for Ethanol (EtOH). Horizontal Vapor Phase Growth (HVPG) Technique was utilized to synthesize monoclinic Gallium Oxide (β-Ga2O3) nanowires. Images obtained from the Scanning Electron Microscope showed high density nanowires specifically in the area of highest temperature gradient. SEM also showed that the grown structures using HVPG Technique were at the nanoscale with diameters ranging from 51.60 to 908.38 nm. Higher surface-to-volume ratio was also noted in the area of highest temperature gradient which was subjected to an applied magnetics field. The Gallium to Oxygen ratio was verified via EDX to be approximately 2:3 which agrees with the atomic ratio of Ga2O3. The monoclinic structure of the grown nanomaterials was investigated using Raman Spectroscopy. Raman peaks of the samples were at 199 and 486 cm−1 which was accounted to the presence of two Raman-active modes of the b-polymorph of Ga2O3. The Raman spectrum of the grown nanowires confirmed that the material is monoclinic in structure and belongs to C2/m space group. The I-V Curve of the grown nanowires were also determined using two-point probe which illustrates a non-linear curve similar to that of a semiconductor material. Furthermore, additional fundamental properties such as resistivity and specific conductance of the materials were also determined via van der Pauw Technique. Results showed that the material has high specific conductance and low resistivity. The synthesized nanomaterial was responsive to Ethanol vapor. Exposure to the said compound increased its resistance. Graphs showed that there is a significant increase in the resistance after exposure to ethanol vapor.
Bending Analysis of Nonlocal Functionally Graded Beams
Authors: Garbin F , Levano A , Arciniega R 
Published: February 2020

Abstract
In this paper, we study the nonlocal linear bending behavior of functionally graded beams subjected to distributed loads. A finite element formulation for an improved first-order shear deformation theory for beams with five independent variables is proposed. The formulation takes into consideration 3D constitutive equations. Eringen’s nonlocal differential model is used to rewrite the nonlocal stress resultants in terms of displacements. The finite element formulation is derived by means of the principle of virtual work. High-order nodal-spectral interpolation functions were utilized to approximate the field variables, which minimizes the locking problem. Numerical results and comparisons of the present formulation with those found in the literature for typical benchmark problems involving nonlocal beams are found to be satisfactory and show the validity of the developed finite element model.
Evaluation of the Evacuation of Essential Buildings: Interaction of Structural and Human Behaviour through Nonlinear Time-History Analysis and Agent-Based Modelling
Authors: Delgado M , Rosales A , Arana V 
Published: February 2020

Abstract
In this article, a performance assessment of the evacuation system is established for educational buildings. Structural and geotechnical information of the building is collected and introduced into a database. A similar procedure was realized for the information related to the occupants. Using this information, a) the structural fragility and localized collapse were determined and b) the interaction of the person with the partial collapse was established. For the first aspect, nonlinear time history was used, and for the second, the agent-based modeling was applied to recreate the reaction of people that face the micro collapse. Therefore, the important results of this evaluation are: 1) To localize collapsed beans and columns that make inoperable evacuation routes, 2) to localize bottleneck areas that people concentration during evacuation, and 3) quantification of affected people, in terms of persons caught up in the building that cannot evacuate.
Numerical Study on Aerodynamic Characteristics of Variable-sweep Morphing Aircraft at Transonic Speeds
Authors: Lei Yuchang , Zhang Dengcheng , Zhang Yanhua , Su Guangxu 
Published: February 2020

Abstract
The variable-sweep morphing aircraft (VMA) has both high speed and low speed flight performance, and can be competent for combat tasks and practical requirements in different flight environments. Aerodynamic characteristics of VMA have a great impact on flight performance. The transonic stage is particularly important in the whole variation process. It is also one of the most difficult problems in aerodynamic layout design of aircraft. In order to explore the aerodynamic characteristics of the VMA at transonic speeds, this paper adopts an efficient engineering algorithm. The aerodynamic characteristics of VMA at different Sweepback Angle, Angle of attack, Mach number and Altitude are analysed. The result demonstrates that: Sweepback Angle has great influence on aerodynamic characteristics of aircraft. For the lift coefficient, at subsonic speeds, small sweep has great influence. When the Angle of attack (AOA) is 12°, the sweepback changes from 45° to 25°, and the lift coefficient increases by 48.9%. At transonic speeds, large sweepback has great influence. When the AOA is 12°, the sweepback changes from 75° to 55°, and the lift coefficient increases by 85.7%. For the drag coefficient, at subsonic speeds, small sweepback has great influence. When the AOA is 12°, the sweepback changes from 45° to 25°, and the drag coefficient increases by 45.5%.All the changes of sweepback have great influence on drag coefficient at transonic speeds. The influence of sweepback on lift-drag ratio is complex. In general, when the Mach number increases, the sweepback corresponding to the maximum lift-drag ratio increases. The altitude factor only has some influence on the drag coefficient at subsonic speeds. These aerodynamic change rules can provide a basis for the shape design and dynamic analysis of VMA.
Study on Magnet Eddy Current Losses in Interior Permanent Magnet Machines for Aircraft Electric Green Taxiing Systems
Authors: Hu Yaohua , Zhang Pengfei 
Published: February 2020

Abstract
The magnet eddy current of multi-layered interior permanent magnet (IPM) machines is studied in the paper for the aircraft electric green taxiing systems. The armature reaction flux density distribution, eddy current density and harmonic spectrum at the end of permanent magnet are analysed. A method to reduce the magnet eddy current of multi-layered IPM machines is presented. That is to increase the distance between outer permanent magnet and rotor surface and the distance between two layers of permanent magnet so as to provide a larger core path for armature reactive flux. This method can effectively reduce the magnet eddy-current loss of the multi-layered IPM machines and improve the operation efficiency.
Investigation of the Influence of Blocking Effect on the Aerodynamic and Hydrodynamic Characteristics of a Powered Aircraft Model
Authors: Xiao Zhijian , Wu Bin , Wang Mingzhen , Hu Qi , Yang Wenjing 
Published: February 2020

Abstract
This paper investigated the influence of blocking effect on the aerodynamic characteristics of a powered aircraft model by experimental and numerical methods. Firstly, the towing test were carried out in the bottom and front of the trailer. The experimental results showed that the darg and trim of two conditions were different, indicating that the blocking effect was obvious. RANS method, slidding mesh and overset grid were adopted in numerical simulation. The simulation of the wind field in the bottom and front of the trailer were carried out. And the numerical results were compared with the experimental results to verify the accuracy of numerical method adopted in this paper. The results showed that the wind speed in the bottom of the trailer was larger than that in the front of the trailer on average and there was stable speed increment interval when the wind filed simulation was conducted in the front and the bottom of the trailer without model. Then the hydrodynamic performance of the powered aircraft model in infinite domain, in the bottom of the trailer and in front of the trailer were carried out respectively. The aerodynamic downward moment was larger when the model was in the bottom, but the overall aerodynamic lift force of the model was similar under the two conditions. The heave amplitude was also similar under the two conditions, but the trim angle and the total drag was smaller when the model was in the bottom of the trailer.
Spacecraft’s Partially Invariant Stabilization System
Authors: Zosimovych Nickolay 
Published: February 2020

Abstract
In most of the known spacecraft stabilization systems the control signal in the centre of mass movement channel is generated according to proportional plus integral control law, based on the measurements of tangential velocity of the centre of mass and its integral-linear drift. In the angular stabilization channel, the control signal shall be generated in proportion to the spacecraft deviation angle in the transverse plane and the angular velocity of the spacecraft rotation in this plane. In practice, a spacecraft’s stabilization system, which is partially invariant to the disturbing moment, is the easiest to implement. The velocity performance limitation of the control actuator has the most influence upon stability of the system among all the nonlinearities considered in the mathematical modelling. Therefore, we shall consider a model of an invariant stabilization system with due regard to nonlinearity. For the system under consideration, it is possible to construct lines of equal values of the auto oscillation amplitude in a two-parameter plane. The study of the stability of the proposed partially invariant stabilization system revealed that it is possible to ensure sufficient stability margins in the system under consideration by choosing parameters for the stabilization controller. At the same time, it allows to provide high quality of the transition process.
Quick Trajectory Optimization Method for Mars Airplane Based on Adaptive Gauss Pseudospectral Method
Authors: Sun Z Y , Liu Z Y , Zhang P 
Published: February 2020

Abstract
This paper gives a new method based on adaptive Gauss pseudospectral method for quick trajectory optimization problem of Mars airplane. The method converts the trajectory optimization problem to a non-linear programming problem, taking into account for the dynamic constrains, the boundary constrains, the path constrains and the control constrains during the cruise phase of the Mars airplane. And the sequential quadratic programming is adapted to solve the non-linear programming problem. In combination with the adaptive Gauss pseudospectral method and sequential quadratic programming in Matlab, numerical results of the optimal trajectory with 267 collocations could be obtained in 800s with an approximation accuracy of 10−6.
Certification Techniques for the Deformation Compliance of Civil Aviation Passenger Seat
Authors: Jianbin Zhou , Xinyuan Zhang , Xiaozheng Wang 
Published: February 2020

Abstract
The deformation requirements for passenger seats of civil aviation are complicated. The author provides the experience of real civil aviation programs for seat deformations’ certification, including the significance of seat deformations’ airworthiness compliance, relevant regulations and tests and the measuring requirements for passenger seat deformations. FAR25 and CCAR25 both require that the passenger seats shall not yield to the extend they would impede rapid evacuation of the airplane occupants, but the relevant factors are not defined clearly. Seat deformations are the key factors that would impede occupants’ rapid evacuation. This article discussed the related requirement and the right way to measure and analyze seat deformations.
Experimental Study on the Attitude of Civil Aircraft Ditching with High Horizontal Tail Configuration
Authors: Nanbo Xu , Yuping Wang , Lin Fu , Qing Zhou 
Published: February 2020

Abstract
The airplane must meet the airworthiness requirements if certification with ditching provisions is requested. The probable behavior of the airplane ditching must be investigated by model tests or by comparison with airplanes of similar configuration. In this paper, aircraft with high horizontal tail configuration is considered as a research object, then the attitudes of civil aircraft in ditching is studied through a scaled model verification experiment. On this basis, this paper researches the effects of different parameters after ditching into the water, such as initial pitch angle, flap slat configuration and sinking speed. The research results in this paper can help to determine the ditching attitudes and parameters and thus develop strategies for ditching.