bluuebunny/crossref_metadata_2025 huggingface dataset:
Online blend‐type identification during co‐firing coal and biomass using SVM and flame emission spectrum in a pilot‐scale furnace
Authors: Zhou Hao , Li Yuan , Cen Kefa
Published: October 2018

Co‐firing coal and biomass has been applied in existing coal‐fired power stations recently. Online blend‐type identification was investigated by support vector machine (SVM) using flame emission spectrum for combustion optimisation. A spectrometer was used to capture the flame emission spectrum during co‐combustion in a 0.3 MW furnace. A total of 22 flame features were defined and extracted from the flame emission spectrum for blend‐type identification. ReliefF was applied to calculate the important weights of the extracted fame features. Alkali metals atomic excitation spectral intensities and the means of spectral signals show obviously higher important weights than the other flame features. Ultraviolet signal is more important than visible and infrared signals for blend‐type identification. SVM was adopted to identify the blend types. The method of ‘ReliefF + SVM’ was proposed to obtain the optimum feature vector. The number of optimum features can be reduced from 22 to 17 if only the prediction accuracy is considered. The optimum sampling number is 12. At the optimum feature vector (17 features) and the optimum sampling number (12), the average prediction accuracy of the five fuels is 99.67%. The results demonstrate that combining SVM and flame emission spectrum is suitable for online blend‐type identification during co‐combustion.
Structure design of a miniature and jumping robot for search and rescue
Authors: Wang Xueying , Yang Xiaojing
Published: October 2018

The extremely dangerous and complex environment caused by tremendous earthquakes or unnatural disasters usually brings great danger to survivors and salvagers. Therefore, search and rescue missions after any disaster indicate a huge need in special access to reduce the loss for human beings and, at the same time, to improve the capability of performing the tasks. In terms of the miniature robots which can go into the confined zone for the searching tasks, this project focuses specially on analysing climbing obstacle capability of the miniature robots, and introduces a new concept composed of a jumping robot which is mounted on a tracked mobile base. To design, calculate, and analyse this system, an appropriate mechanism, geometric dimensions, and specific properties are detailed, which include a dual‐tracked articulated transformable locomotion system, a transmission system with a sleeve shaft, an incomplete gear jumping mechanism, and the selection and calculation of power system motors. To complete the design procedure, a three‐dimensional sketch of each component of the robot was generated by means of Solidworks.
Research on adaptive modulus maxima selection of wavelet modulus maxima denoising
Authors: Ding Wensi , Li Zhiguo
Published: October 2018

Microelectromechanical system (MEMS) accelerometers are small in size, low in power consumption and easily integrated. They can be used in intelligent hydraulic components to obtain the dynamic acceleration of the system and monitor the operating status of the system. In this study, based on the noise characteristics of MEMS accelerometer output signals, a wavelet modulus maxima denoising algorithm based on adaptive threshold estimation is proposed, in which SureShrink threshold estimation is used to choose the right modulus maxima. Then, the signal‐to‐noise ratio and mean‐square‐error are used as the evaluating indices of the denoising performance for the wavelet modulus maxima denoising based on SureShrink threshold estimation, the wavelet modulus maxima denoising based on BayesShrink threshold estimation and the normal wavelet modulus maxima denoising. The simulation results show that the wavelet modulus maxima denoising based on SureShrink threshold estimation has better denoising performance than the normal modulus maxima denoising and the wavelet modulus maxima method based on BayesShrink threshold estimation, and effectively eliminates the noise of MEMS accelerometer output signals.
Dynamic characteristic analysis and fault diagnosis of load‐sensitive drive system for loaders
Authors: Liu Yanhui
Published: October 2018

A certain type of crawler loader often appears flameout in unilateral steering, which makes the performance of the whole machine greatly affected. By analysing the dynamic characteristics of the load‐sensitive drive system, it is found that the hydraulic fluctuation and the power matching between the hydraulic pump and the engine are the fundamental reasons for the failure. In order to solve this problem, a simple and easy improvement scheme is designed on the premise of not affecting the engine efficiency: a suitable size damping is connected in the middle of the two load feedback lines of the drive system to solve the power matching between the engine and the hydraulic pump and reduce the hydraulic fluctuation of the system. Simulation and experimental results show that this method can effectively solve the problem of stalling in the steering process of loaders and greatly improve the dynamic performance of the system.
Numerical–experimental research on the influence of inclined angle on the flow characteristics of angle seat valve
Authors: Wang Yangding , Zheng Zhijian , Yu Fangfang , Qian Mi , He Liang
Published: October 2018

The influence of inclined angle on the flow characteristics of angle seat valve is investigated by the numerical and experimental study. The accuracy of numerical modelling and calculation is verified by comparing the flow coefficients obtained from numerical simulation and experiments under the different pressure difference at the inclined angle of 45° and 60°. The experiment results showed that the highest flow velocity, the maximum flow coefficient, and the minimum flow resistance exist as the inclined angle is 45°. The flow coefficient increases as the increase of inclined angle when it ranges from 45° to 60°, and the flow resistance decreases correspondingly. The observed result is discussed and explained by the computational fluid dynamics (CFD) method. The calculation results indicated that the flow coefficient mainly depends on the maximum flow velocity in the angle seat valve. Moreover, the flow capacity is also affected by the flow direction near the sealing surface, and the number, locations and intensities of flow vortex.
Research on modelling and simulation of a new variable displacement oil pump
Authors: Zhang Wei , Wang Bin , Zhang Yanhuan , Peng Lele , Liu Mohan , Lv Yancheng
Published: October 2018

A new variable displacement oil pump has been modelled and simulated by using AMESim. Through the comparison and analysis of the simulation curve and the test data of this pump, it is found that the volume efficiency of it is unsatisfactory when the rotational speed is too high. The mechanical structure model of the pump was established by using ADAMS to confirm that the cause of the problem is redundant force on the variable device. On this basis, the redundant force acting on the variable device is theoretically deduced to prepare for the improvement of the pump.
Dynamic characteristics analysis and dual motor synchronous control of hydraulic lifting system for large cranes
Authors: Wu Lan , Wang Lihua , Zhang Chunyou , Shi Hongyan
Published: October 2018

The hydraulic lifting system is the key part of the crane. A sliding mode control method based on the cerebella neural network is proposed to solve the problem that the robustness of the traditional control method is poor in view of the problem of the synchronous error of the double motor in the lifting process of the crane. On the basis of the master and slave control, the outlet pressure of the hydraulic pump and the angle of the hook are simulated as the control index. Finally, the experimental study is carried out on the lifting condition. The results show that, compared with the traditional method, the proposed control strategy can effectively improve the synchronisation control precision of two motors, strong anti‐interference ability and good robust performance.
Design and modelling of CRB cutting equipment for batch processing
Authors: Yang Lijie , Wang Guimei , Zong Zhikun , Zhang Huadong
Published: October 2018

Ceramic roller is more reliable than metal roller. However, ceramic materials are difficult to process due to their high hardness and great brittleness. They are easy to crack and easy to damage cutting tools. To batch processing of ceramic roller blanks (CRBs), a special ceramic roller cutting equipment (SCRCE) is designed to deal with CRBs of different diameters and lengths. To avoid clamping damage to CRBs, the SCRCE adopts the new clamping mechanism. The blanks are orientated to double rotating shafts with V‐type sleeves to reduce friction. Moreover, the SCRCE adopts a new ring‐cut method. The ring‐shape cutting is used. The cutting spindle and the blanks are revolving at the same time in cutting processing. The design and modelling of the special cutting equipment is also finished. To analysis the axial displacement of CRBs while cutting, the simulation model with ADAMS is built and the related characteristic is simulated. The test result shows that the new type cutting machine is suitable for ceramic roller blank cutting process.
System study of pneumatic exoskeleton rehabilitation manipulator
Authors: Ma Xudong , Yuan Ruibo , Fang Sizhong
Published: October 2018

In this study, biological characteristic of manpower is analysed and then the structural of exoskeleton rehabilitation manipulator is designed base on the thought of modular. First, the overall assembly drawing is drawn by SolidWorks. Second, the controlled pneumatic system is designed. The mainly contents are selecting mini pneumatic cylinder as a driver and controlling electromagnetic reversing valve which can lead to the piston movement of cylinder by STM32F429 microcontroller. At last, the movement simulation of exoskeleton rehabilitation manipulator is done and analysed by ADAMS, and then the experimental research of the same move pattern with simulation is carried out. It is proved that the pneumatic exoskeleton rehabilitation manipulator system has certain reliability and feasibility. Furthermore, it has the ability to meet the rehabilitation needs of patients with finger movement disorders.
Study on the vibration isolation characteristics of an anti‐resonant hydropneumatic suspension
Authors: Sohail Aamir , Liu Chunrong
Published: October 2018

A novel anti‐resonant hydropneumatic suspension system was presented in this study. The mathematical model of the presented suspension system was derived and the theoretical analysis was carried out. For lower frequency vibrations, the presented suspension system can achieve better vibration isolation performance comparing with the traditional hydropneumatic suspension system. The frequency spectrum on which the presented suspension achieves better vibration isolation performances can be widened by adjusting the length of the oil tube. Therefore, it is possible for the presented suspension system to achieve better vibration isolation performance on different road conditions.
New structure of pneumatic networks actuators for soft robotics
Authors: Wang Yazhou , Xiao Junfeng , Chen Xueping
Published: October 2018

Pneumatic actuators (referred to as pneu‐nets) are drawing increasing attention due to their high customisability, ease of fabrication and innate softness. The actuator's ability to bend is one of the important parameters characterising its performance and related to its structure. Some structures are developed. In this work, a new structure (NS) pneu‐nets is developed, and its bending ability is compared with the currently common Mosadegh pneu‐nets structure (developed by Mosadegh). These two are analysed in two aspects: the trajectories of the pneu‐nets actuator's tip, and the defined angle of bending. The results indicate that the NS pneu‐nets actuators are able to achieve greater bending at higher pressures and can be lightweight. These pneumatic actuators provide improved structure for soft robotics.
Comparative evaluation on friction and wear characteristics of SiC, Si3 N4, Al2 O3, and ZrO2 sliding against PEEK composite for seawater hydraulic axial piston pumps
Authors: Zhang Zhenhua , Yang Lijie , Wu Xiangyang , Li Chunping , Wang Fei
Published: October 2018

Comparative investigation on friction and wear properties of SiC, Si3 N4, Al2 O3, and ZrO2 lubricated with seawater was carried out on a ring‐on‐ring contacted tribological test apparatus, and their worn surfaces were observed by an ultra‐depth optical microscope. The results reveal that the friction coefficients of Si3 N4 and SiC are obviously lower than those of Al2 O3 and ZrO2 when they slide against the polyetheretherketone (PEEK) composite in seawater, and the friction stability of ZrO2 is so poor that it is not suitable for seawater hydraulic piston pumps. When the contacted load increases from 400 to 1000 N, the wear rate of Al2 O3 is still the highest, while the wear rates of SiC and Si3 N4 change from positive to negative, which indicates that plastic transfer is occurred under a heavier load. When they slide against the PEEK in seawater, the main tribological mechanism of SiC, Si3 N4, and Al2 O3 is slightly abrasive wear, while both abrasive wear and adhesive wear occur for ZrO2. Generally, both SiC and Si3 N4 have wide prospect applied in seawater hydraulic piston pumps, and particularly Si3 N4 exhibits excellent friction and wear properties in seawater.
Active vibration control of smart flexible piezoelectric beam with a tip mass using hybrid FX‐VSSLMS algorithm
Authors: Wang Xiaopeng , Gao Zhiyuan , Fang Yubin , Hu Jiaming , Zhu Xiaojin
Published: October 2018

This study concerns adaptive feedforward and hybrid (combined feedback and feedforward) control systems for active vibration suppression of smart flexible beam with a tip mass. By analysing traditional feedforward filtered‐X least mean square (FXLMS) algorithm and filtered‐X variable step size least mean square (FX‐VSSLMS) algorithm, a new hybrid FX‐VSSLMS algorithm is developed to improve the control performance of feedforward controllers. A stainless steel beam with a tip mass is employed to simulate flexible robot arm with varying loads. Piezoelectric actuators and sensors are attached to the surface of the beam. Comparison experiments show the effectiveness and benefits of the proposed hybrid FX‐VSSLMS method.
Mechanical analysis and verification of the large‐scale rack structure about the zero‐gravity test of manipulator of the space station
Authors: Dai Hailin , Zhang Chengli , Meng Fanwei , Meng Shaohua , Gao Feng
Published: October 2018

In this article, the mechanical properties of large‐scale rack structures are analysed by MSC Marc analysis software is verified through the modal test. The modal frequency and modal shape are obtained through the finite element analysis and LMS data acquisition system for modal test verification. It is showed that the modal shape of the modal test and the calculation by finite element analysis are consistent, which verifies the inherent characteristics of the frame structure effectively and provides reliability parameters of the manipulator for the space station in the zero‐gravity test.
Performance prediction of tobacco flavouring using response surface methodology and artificial neural network
Authors: Chen Lin , Yuan Ruibo , Liu Ze
Published: October 2018

This study was to predict the optimum condition for leaf flavouring in cigarette manufacturing. To this purpose, an integrated research was used by using response surface and artificial neural network. A series of tobacco flavouring experiment's factors were designed by Experimental Design software. The MATLAB software's Neural Network function was used to forecast the responses, and the optimal solution configuration was coming out from the Response Surface Analysis Method. In the optimum condition, moisture removal opening, roller speed and tobacco process flow, pressure and feed liquid gas ejector flow are 18.60%, 10.74 rpm, 5314.11 kg/h, 3.70 bar and 243.63 kg/h, uniformity of the evaluation index and the utilization rate of material liquid distribution are 93.088% and 98.694%. With the corresponding experimental, results are consistent, under the condition of the error to less 7%, the test results show that through a few experimental data of predictive results of the neural network and response surface design has a certain practicability.
Parameters design for a non‐linear absorber based on phase trajectory analysis
Authors: Liu Yuan , Wang Feng , Han Dedong
Published: October 2018

The performance of non‐linear absorbers for suppression of the structure vibrations depends on the setting of the absorbers' parameters to a certain extent. A slowly varying dynamical system under investigation in the existing work is comprised of a linear oscillator coupled with an attached non‐linear absorber called non‐linear energy sink (NES). Slowly varying equations of the coupled system are achieved first by using the complex averaging method, and trajectory features of the slowly varying system are analysed. On that basis, the non‐linear cubic stiffness design method is proposed. Considering that different damping coefficients of the NES impose a large impact on both system energy transfer and energy dissipation between the main structure and the NES, necessary damping conditions for the targeted energy transfer (TET) are obtained by using the phase trajectory analysis. With the proposed method, structure parameters of the NES are designed to get maximum absorbing effects. Finally, all these conclusions about parameters design for the NES are verified by simulation analysis. The simulation results demonstrate that the optimal vibration reduction effectiveness can be achieved with reasonably designed stiffness and damping.
Highly photoactive Ag‐based urchin‐like E‐g‐C3N4/TiO2 ternary composite photocatalyst
Authors: Zhou Yi , Zhao Dawei , Cao Feng , Luo Qinsheng , Xiang Ye , Deng Yuehong
Published: October 2018

Herein, silver (Ag)‐based urchin‐like E‐graphite carbon nitride/titanium dioxide (E‐g‐C3N4/TiO2) ternary composite was successfully synthesised via hydrothermal process and it showed excellent photocatalytic activity. The large interfacial contact between three‐dimensional (3D) urchin‐like TiO2 (UT) and g‐C3N4 leads to high photocatalytic activity, compared with pure 3D UT. To enlarge the response of light and enhance the charge carriers’ transfer, the Ag nanoparticles with average sizes of 13 nm were loaded on the surface of g‐C3N4/TiO2. Photodegradation test results of RhB shown that the 3% Ag‐based urchin‐like E‐g‐C3N4/TiO2 composite has the highest catalytic activity, which reaches 97.98%. Thus, the material has a promising application for the degradation of organics.
Effect of aging heat treatment on the microstructure and hardness of a serviced ZHS32 superalloy
Authors: Shademani Mohammad , Sedaghat Ahangari Hossein Zadeh Ali , Rahimipour Mohammad Reza , Farvizi Mohammad
Published: October 2018

According to the gradual changes of the microstructure of superalloys during harsh service condition of turbine blades and the detrimental effects of these changes on the mechanical properties of superalloys, performing of a rejuvenation heat treatment (solution treatment + aging process) on ex‐serviced superalloys is necessary. In this work, the aging heat treatment was conducted on a serviced single crystal ZHS32 superalloy in the temperature range of 950–1150°C. It was found that while performing the aging process at 950 and 1050°C for 10 h did not provide appropriate conditions for the nucleation and growth of primary ϒ′ phases, conducting aging at the temperature of 1150°C for 10 and 16 h yields to the formation of ϒ′ precipitates with the desired cuboidal morphology. The comparison of the microstructure of the rejuvenated samples with the un‐rejuvenated samples confirms that with applying this procedure, the size of strengthening ϒ′ precipitates reduces and the volume fraction of these phases considerably increases, which yields to the recovery of the superalloy microstructure and improvement of its mechanical properties such as hardness.
Effects of rotational restraints on the thermal buckling of carbon nanotube
Authors: Yayli Mustafa Özgür
Published: October 2018

The thermal buckling response of nanotubes with rotational restraints is investigated using a Timoshenko beam model with non‐local elasticity theory. Two trigonometric (Fourier) series are selected to analyse the thermal buckling of the non‐local Timoshenko nanotube with rotational restraints. Explicit equations are obtained for the boundary values with a coefficient matrix. In particular, the new method can be degenerated to the non‐local Euler beam model by assigning proper value to the shear correction factor. The main advantage of the present technique is its capability of dealing with deformable or rigid supporting conditions. Several numerical examples are solved to asses proposed approach reliability. The results show that thermal buckling including the thermal effects are lower than those without the thermal effects when the temperature rises. The rotational restraint springs have significant effects on the buckling response of nanotubes.
Development of hot embossing setup and fabrication of ordered nanostructures on large area of polymer surface for antibiofouling application
Authors: Patil Deepak , Sharma Anagdha , Aravindan Sivanandam , Rao Paruchuri Venkateswara
Published: October 2018

Nanostructured polymeric film has wide range of applications in different fields. However, the existing processes of fabrication of nanostructures on polymer surfaces are limited to very small area and throughput of the processes is very low. In order to solve this challenge, the indigenous hot embossing setup was developed which is capable of patterning micro‐nano structures on large area. In this work, the steps for the development of hot embossing setup are discussed. The setup requires nanostructured mould, copper‐chromium block, pencil heaters and temperature controlled system (thermostat and thermocouple). Two different types of nanostructures (groove and pillars) were successfully replicated on polystyrene film. The fabricated nanostructures were characterised using field emission scanning electron microscope and atomic force microscope. The dimensions of fabricated nanostructures are close to the mould dimensions with few defects (shrinkage defects). The wettability test was performed using goniometer on plain and structured polystyrene film to study the effect of structures on the wettability of the surface. It was observed that the hydrophilic (water droplet contact angle: 43°) polystyrene film got converted into hydrophobic (water droplet contact angle: 102–112°) nature. The fabricated structured surfaces have shown antibiofouling property which was confirmed through plate counting method.
Preparation of amino silane magnetic nanocomposite by the sol–gel process and investigation of its antibacterial activity
Authors: Hatami Raana , Allafchian Alireza , Karimzadeh Fathallah , Enayati Mohammad Hosein
Published: October 2018

The results of a comparative investigation on microstructure and magnetic characteristics of silane magnetic nanocomposites coated with silver nanoparticles (AgNPs) are presented. The authors used tetraethyl orthosilicate (TEOS) with (3‐aminopropyl) triethoxysilane (APTES) to improve the antibacterial properties of AgNPs. On the basis of this approach, TEOS‐APTES polymer was made by the sol–gel method. A layer of the polymer was set on the magnetic core of Fe3O4 NPs and then AgNPs were coated on the TEOS‐APTES surface. Therefore, the core–shell structure of the Fe3O4/TEOS‐APTES/Ag polymer nanocomposite was synthesised. To characterise the crystal morphology, structure, and size of nanocomposites, various techniques and experiments including Fourier transform infrared spectroscopy, X‐ray diffraction, field‐emission scanning electron microscope, dynamic light scattering, and transmission electron microscope were used. Vibrating sample magnetometer showed the magnetic properties of the samples. Finally, antibacterial activity against Gram‐negative and Gram‐positive bacteria including Escherichia Coli ( American Type Culture Collection (ATCC) 35218), Salmonella typhimurium (ATCC 14028), Staphylococcus aureus (ATCC 292113) and Bacillus cereus (ATCC 14579) was showed by the disc diffusion analysis. The results indicated the uniform distribution of AgNPs on the polymer surface. Fe3O4/TEOS‐APTES/Ag nanocomposite showed much better antibacterial activity in comparison with AgNPs only.
Solar total and spectral irradiance reconstruction over the last 9000 years
Authors: Wu C.-J. , Krivova N. A. , Solanki S. K. , Usoskin I. G.
Published: October 2018

Context.Changes in solar irradiance and in its spectral distribution are among the main natural drivers of the climate on Earth. However, irradiance measurements are only available for less than four decades, while assessment of solar influence on Earth requires much longer records.

Aims.The aim of this work is to provide the most up-to-date physics-based reconstruction of the solar total and spectral irradiance (TSI/SSI) over the last nine millennia.

Methods.The concentrations of the cosmogenic isotopes14C and10Be in natural archives have been converted to decadally averaged sunspot numbers through a chain of physics-based models. TSI and SSI are reconstructed with an updated SATIRE model. Reconstructions are carried out for each isotope record separately, as well as for their composite.

Results.We present the first ever SSI reconstruction over the last 9000 years from the individual14C and10Be records as well as from their newest composite. The reconstruction employs physics-based models to describe the involved processes at each step of the procedure.

Conclusions.Irradiance reconstructions based on two different cosmogenic isotope records, those of14C and10Be, agree well with each other in their long-term trends despite their different geochemical paths in the atmosphere of Earth. Over the last 9000 years, the reconstructed secular variability in TSI is of the order of 0.11%, or 1.5 W m−2. After the Maunder minimum, the reconstruction from the cosmogenic isotopes is consistent with that from the direct sunspot number observation. Furthermore, over the nineteenth century, the agreement of irradiance reconstructions using isotope records with the reconstruction from the sunspot number by Chatzistergos et al. (2017, A&A, 602, A69) is better than that with the reconstruction from the WDC-SILSO series (Clette et al. 2014, Space Sci. Rev., 186, 35), with a lowerχ2-value.
Non-standard s-process in massive rotating stars
Authors: Choplin Arthur , Hirschi Raphael , Meynet Georges , Ekström Sylvia , Chiappini Cristina , Laird Alison
Published: October 2018

Context. Recent studies show that rotation significantly affects the s-process in massive stars.

Aims. We provide tables of yields for non-rotating and rotating massive stars between 10 and 150 M⊙ at Z = 10−3 ([Fe/H] = −1.8).

Tables for different mass cuts are provided. The complete s-process is followed during the whole evolution with a network of 737 isotopes, from hydrogen to polonium.

Methods. A grid of stellar models with initial masses of 10, 15, 20, 25, 40, 60, 85, 120, and 150 M⊙ and with an initial rotation rate of both 0% or 40% of the critical velocity was computed. Three extra models were computed in order to investigate the effect of faster rotation (70% of the critical velocity) and of a lower 17O(α, γ) reaction rate.

Results. At the considered metallicity, rotation has a strong impact on the production of s-elements for initial masses between 20 and 60 M⊙. In this range, the first s-process peak is boosted by 2−3 dex if rotation is included. Above 60 M⊙, s-element yields of rotating and non-rotating models are similar. Increasing the initial rotation from 40% to 70% of the critical velocity enhances the production of 40 ≲ Z ≲ 60 elements by ∼0.5−1 dex. Adopting a reasonably lower 17O(α, γ) rate in the fast-rotating model (70% of the critical velocity) boosts again the yields of s-elements with 55 ≲ Z ≲ 82 by about 1 dex. In particular, a modest amount of Pb is produced. Together with s-elements, some light elements (particularly fluorine) are strongly overproduced in rotating models.
Utilisation de pratiques agroécologiques et performances de la petite agriculture familiale : le cas de la Guadeloupe
Authors: Rasse Camille , Andrieu Nadine , Diman Jean-Louis , Fanchone Audrey , Chia Eduardo
Published: October 2018

L’analyse et la quantification des performances de la petite agriculture familiale (PAF) constituent un enjeu au regard de la transition agroécologique. Cet article utilise une méthode combinant enquêtes auprès d’agriculteurs de la PAF de Guadeloupe, typologie et évaluation, à l’échelle de l’exploitation, des avantages qu’ils tirent de pratiques agroécologiques en termes de production de biomasse, de couverture des besoins caloriques de la famille, d’efficience azotée, d’économie d’intrants ou de production de valeur ajoutée. Il montre que la PAF est diverse et hybride usage de pratiques agroécologiques et d’intrants de synthèse. En fonction du nombre de pratiques agroécologiques mises en œuvre et de l’orientation de la production, on observe des synergies entre le nombre d’espèces domestiquées, la diminution des charges intermédiaires et la couverture des besoins de la famille. Des tensions ont en revanche été observées entre ces indicateurs et la valeur ajoutée brute commerciale. Des synergies sont néanmoins possibles entre la majorité des indicateurs lorsque le producteur intègre des espèces à haute valeur ajoutée, ce qui permet d’identifier des pistes pour favoriser la transition agroécologique de ces systèmes.
Questions de genre et développement durable : le potentiel de l’agroécologie dans le Nordeste du Pará, Brésil
Authors: Centrone Francesca Alice , Tonneau Jean-Philippe , Piraux Marc , Cialdella Nathalie , De Sousa Leite Tania , Mosso Angela , Calvo Angela
Published: October 2018

L’agriculture mondiale est confrontée à de nombreux défis en termes de souveraineté alimentaire. Il s’agit d’abord d’assurer un accès équitable à la nourriture et aux produits agricoles de première nécessité pour une population mondiale croissante. Il s’agit ensuite d’inclure la production agricole dans une perspective plus générale de lutte contre la pauvreté, l’inégalité et la malnutrition dans le monde. Il s’agit enfin de contribuer à une gestion plus durable des ressources naturelles et agricoles et de la biodiversité. L’approche agroécologique semble être l’une des options les plus appropriées pour atteindre ces objectifs, en raison de son caractère holistique concernant l’utilisation des ressources et des processus naturels, qui profite à la fois aux agriculteurs, à l’agriculture durable et à des modèles de consommation alimentaire plus sains. En outre, l’agroécologie est conçue pour soutenir des relations sociales plus égalitaires, en particulier entre hommes et femmes. Néanmoins, l’analyse des relations et des implications entre l’agroécologie et les questions de genre reste une question relativement inexplorée. L’objectif de cet article est donc d’analyser de manière critique et de mettre en évidence les principales opportunités et contraintes de l’agroécologie en termes de durabilité et d’égalité des sexes. La recherche a été réalisée dans le cadre d’expériences agroécologiques menées dans le Nord-Est de l’Amazonie brésilienne, où les agricultrices pratiquent principalement l’extractivisme et où l’agroécologie est encore dans une phase d’émergence comparativement à d’autres régions du pays. Pourtant, malgré leur faible reconnaissance et leur accès limité aux ressources, les femmes contribuent activement à la conservation de la biodiversité et au transfert des connaissances traditionnelles.
Study on desulfurization capacity of high alumina blast furnace slag at 1773 K using slag-metal equilibrium technique
Authors: Talapaneni Trinath , Yedla Natraj , Sarkar Smarajit
Published: October 2018

In the current paper, we have determined the desulfurization ability of a CaO–MgO–SiO2–Al2O3 slag system using slag-metal equilibrium technique. The chemical composition of slag samples consists of Al2O3 in the range of 25–30 wt%, CaO/SiO2 ratio (0.8–1.6) and MgO (8–16 wt%). All the experiments are conducted at a temperature of 1773 K. The sulphur content in the slag as well as in metal after desulfurization reaction is analyzed using XRF (X-ray Fluorescence Spectroscopy) for calculating sulphur partition ratio (LS) of the slags. The influence of Al2O3, CaO/SiO2 ratio and MgO content on LS have been studied. It is observed that LS increase with an increase in CaO/SiO2 ratio and MgO content, but it reduces as the Al2O3 content increase in slag. Also, the amount of bridge oxygen ([BO]) represented by (O0) decreases with increase in basicity and MgO content. However, O0 increases with increase in Al2O3. It is witnessed that the experimental values closely fit with the values obtained from corrected optical basicity model.
Effect of Mg addition on carbides in H13 steel during electroslag remelting process
Authors: He Bao , Li Jing , Shi Cheng-bin , Wang Hao
Published: October 2018

The effect of Mg on carbides precipitation in H13 steel was studied based on the Thermo-Calc thermodynamic calculation. The results showed that the precipitation temperature of MC phase was significantly improved by adding Mg. The Mg addition had no effect on the type of precipitated carbides. The as-cast microstructure and the characteristic of carbides in Mg-containing H13 steel were analyzed by OM and SEM-EDS. The results showed that the segregation of as-cast microstructure was released and the size of carbides was reduced by increasing Mg. The distribution of carbides was more homogeneous. The formed MgO · Al2O3 arising from Mg treatment provided preferred nucleation site for TiN, which was the core of heterogeneous nucleation of carbides, resulted in decreasing the size of carbides. Furthermore, partial Mg would melt into the carbides, which would change the morphology of carbide and induce the formation of leaf-like carbides. The electron probe micro-analysis (EPMA) results showed that the segregation of V and Mo in H13 steel was inhibited by Mg, and the dissolved Mg in carbide promoted the heterogeneous nucleation of carbides.
A review on magnetically assisted abrasive finishing and their critical process parameters
Authors: Kumari Chinu , Chak Sanjay Kumar
Published: October 2018

Magnetically assisted abrasive finishing (MAAF) processes are the precision material removal processes that have been applied to a large variety of materials from brittle to ductile and from magnetic to non magnetic. The MAAF process relies on a unique “smart fluid”, known as Magnetorheological (MR) fluid. MR fluids are suspensions of micron sized magnetizable particles such as carbonyl iron, dispersed in a non-magnetic carrier medium like silicone oil, mineral oil or water. The MAAF processes overcome the limitation of abrasive flow machining by deterministically control the abrading forces by applying magnetic field around the workpiece. MAAF process is divided into two parts; one is magnetorheological finishing (MRF) and another is magnetorheological abrasive flow finishing (MRAFF). The MRAFF process gives better results as compared to results of MRF because it has additional reciprocating motion of MR fluid. In this article the attempt has been made to review various technical papers related to MRF and MRAFF. The experimental setups, process parameters, MR fluid, modeling & optimization and applications are discussed in this paper. This review article will be useful to academicians, researchers and practitioners as it comprises significant knowledge pertaining to MAAF.
Asymptotic stability of a polar vortex perturbed by harmonic waves describing atmospheric gravity waves circulating in an equatorial plane of a spherical planet
Authors: Ibragimov Ranis , Mohazzabi Pirooz , Roembke Rebecca , Van Ee Justin
Published: October 2018

We examine stability of the vortex that represents one particular class of exact solution of a a nonlinear shallow water model describing atmospheric gravity waves circulating in an equatorial plane of a spherical planet. The mathematical model is represented by a two-dimensional free boundary Cauchy–Poisson problem on the nonstationary motion of a perfect uid around a solid circle with a sufficiently large radius so that the gravity is directed to the center of the circle. It is shown that the model admits two functionally independent nonlinear systems of shallow water equations. Two essential parameters that control stability of the vortex for both systems are identified. The order of their importance is analyzed and it is shown that one of the systems is more resistant to small perturbations and remains stable for larger range of these two parameters.
L’optique hyperfréquence : un défi perpétuel
Authors: Alouini Mehdi
Published: October 2018

D’une science que l’on pouvait qualifier de confidentielle il y a trente ans, car s’adressant principalement aux besoins de la défense comme le radar et la guerre électronique, l’optique hyperfréquence s’est démocratisée ces dernières années. Elle s’invite désormais dans la plupart des nouveaux systèmes électroniques haute fréquence, les télécommunications optiques cohérentes et la métrologie temps-fréquence par exemple.
Governmental subsidy policies and supply chain decisions with carbon emission limit and consumer’s environmental awareness
Authors: Xu Lang , Wang Chuanxu , Miao Zhuang , Chen Jihong
Published: October 2018

The carbon emission reduction has become an inevitable trend. Under the low-carbon environment, the government has been acting as an important role in the operation and management of supply chain. This paper considers four different governmental subsidy strategies, which includes none of members is subsidized (NS Scenario), only retailer is subsidized (RS Scenario), only manufacturer is subsidized (MS Scenario) and both members are subsidized (SS Scenario). A Stackelberg game model, which incorporates both governmental regulation and consumer’s awareness of carbon emission, is developed to present the pricing and emission reduction behaviors for the supply chain members as well as the subsidy policies of government under different governmental subsidy strategies, and analyze the impact of relevant coefficients on the decisions and supply chain profits. It can be concluded that subsidizing to both members is more profitable for supply chain members and government in terms of environment protection and economic development. The results provide some managerial insights for the decision-makers and policy-makers to implement sustainability initiatives.
A hybrid algorithm Tabu Search – GRASP for wounded evacuation in disaster response
Authors: Khorbatly Mohamad , Dkhil Hamdi , Alabboud Hassan , Yassine Adnan
Published: October 2018

Natural and triggered-disasters, have devastating and profound negative effects on human lives that require a speedy declaration of an emergency in order to minimize their severe consequences. Hence, a prompt disaster response, in addition to effective measures such as informed decision making, organized evacuation plan, right hospital selection, proper rescue vehicles, efficient resources assignment and timely vehicle scheduling are critical actions needed to organize successful secured operations that could, if well prepared, save many injured bodies and lessen the human distress. To reach this ultimate goal, a complicated procedure should be in place and any failure can potentially increase the number of causalities, thus a complete alertness and full caution should be exercised. In this paper, we treat the Integrated Problem of Ambulance Scheduling and Resource Assignment (IPASRA) in the case of a sudden disaster. The main resources to be assigned are the ambulances and the hospitals. While, the hospitals serving capacities might be considered or not according to the extent of disaster and particularly to the wounded bodies’ total number. We formulate the (IPASRA) as a linear model, furthermore a novel hybrid algorithm based on Tabu Search (TS) and Greedy Randomized Adaptive Search Procedure (GRASP) is offered to tackle this complex problem. Simulation tests are also presented to prove the efficiency of our modelling and resolution approaches.
Optimal multi-product supplier selection under stochastic demand with service level and budget constraints using learning vector quantization neural network
Authors: HormozzadehGhalati Hajar , Abbasi Alireza , Sadeghi-Niaraki Abolghasem
Published: October 2018

In today’s competitive marketplace demand, evaluation and selection of suppliers are pivotal for firms, and therefore decision makers need to select suppliers and the optimal order quantities when outsourcing. However, there is uncertainty and risk due to lack of precise data for supplier selection. Uncertainty can impose shortage or overstocks, because of stochastic demand, to firms; in this case, considering inventory control is essential. In this research, an appropriate spatial model is developed for a multi-product supplier selection model with service level and budget constraints. Learning Vector Quantization Neural Network is used to find the optimal number of decision variables with the goal of maximizing the expected profit of supply chains. By analyzing a practical example and conducting sensitivity analysis, we find that corporate profit will be maximized if the optimal integration of suppliers and the optimal order quantities from each supplier is determined. In addition, budget and service level should be considered in the process of finding the best result.
Échelles diffuses : Prospectives de conception via matière et VR
Authors: Bigot-Doll Églantine
Published: October 2018

Dans le cadre d’un enseignement de projet en école d’architecture, nous investiguons ici la question de l’échelle entre monde physique et environnement virtuel. Les objectifs de conception prospective de l’enseignement en question ont permis d’observer les relations entre immersions analogiques et digitales sous le prisme de l’échelle tantôt perdue, tantôt redéfinie dans une quête de matérialité spéculative.
Traçabilité de l’usage des outils de conception dans un processus collaboratif
Authors: Calixte Xaviera , Ben Rajeb Samia , Leclercq Pierre
Published: October 2018

Cet article présente un système de traçabilité des usages d’outil (SysTrac) développé par le Lab for User Cognition & Innovative Design (LUCID), le Collaborative Design and Digital mediations in Architectural Engineering (COLLAeB-BATir) et le Luxembourg Institute of Science and Technology (LIST). Il permet aux concepteurs d’encoder en moins de 5 minutes chacune de leurs activités. Les données récupérées se distinguent en 3 catégories (celles sur l’outil, le temps et l’action). Cet article permet de faire part des premiers constats sur l’opérabilité de cette méthode immersive mise en place pour récupérer la trace des usages des outils des acteurs du projet sur l’ensemble du processus de conception collaborative. La réflexion menée pour créer le SysTrac et son implémentation dans un cas pratique sont détaillées et les premiers résultats y sont illustrés.
Mécanismes de Bricard : Quelles applications dans un système déployable ?
Authors: Lefeu Chloé , Gillet Margaux , Mimram Marc
Published: October 2018

Les mécanismes de Bricard sont des mécanismes complexes et les recherches précédentes sur le sujet sont principalement basées sur leur compréhension mathématique et l’analyse de leur mouvement. La matérialisation physique du mécanisme de Bricard, ses applications et les connections possibles entre plusieurs mécanismes ne sont encore qu’à leurs débuts. Plusieurs utilisations de ces mécanismes sont étudiées dans le domaine des structures déployables à échelle humaine. Des choix de matériaux et de processus de fabrication sont discutés.
Neutron monitor count rate increase as a proxy for dose rate assessment at aviation altitudes during GLEs
Authors: Mishev Alexander , Tuohino Sasu , Usoskin Ilya
Published: October 2018

Radiation exposure due to cosmic rays, specifically at cruising aviation altitudes, is an important topic in the field of space weather. While the effect of galactic cosmic rays can be easily assessed on the basis of recent models, estimate of the dose rate during strong solar particle events is rather complicated and time consuming. Here we compute the maximum effective dose rates at a typical commercial flight altitude of 35 kft (≈11 000 m above sea level) during ground level enhancement events, where the necessary information, namely derived energy/rigidity spectra of solar energetic particles, is available. The computations are carried out using different reconstructions of the solar proton spectra, available in bibliographic sources, leading to multiple results for some events. The computations were performed employing a recent model for effective dose and/or ambient dose equivalent due to cosmic ray particles. A conservative approach for the computation was assumed. A highly significant correlation between the maximum effective dose rate and peak NM count rate increase during ground level enhancement events is derived. Hence, we propose to use the peak NM count rate increase as a proxy in order to assess the peak effective dose rate at flight altitude during strong solar particle events using the real time records of the worldwide global neutron monitor network.
Ultrasound and Cystic Echinococcosis
Authors: Brunetti Enrico , Tamarozzi Francesca , Macpherson Calum , Filice Carlo , Piontek Markus , Kabaalioglu Adnan , Dong Yi , Atkinson Nathan , Richter Joachim , Schreiber-Dietrich Dagmar , Dietrich Christoph
Published: October 2018

The introduction of imaging techniques in clinical practice 40 years ago changed the clinical management of many diseases, including cystic echinococcosis (CE). For the first time cysts were clearly seen before surgery. Among the available imaging techniques, ultrasound (US) has unique properties that can be used to study and manage cystic echinococcosis. It is harmless, can image almost all organs and systems, can be repeated as often as required, is portable, requires no patient preparation, is relatively inexpensive and guides diagnosis, treatment and follow-up without radiation exposure and harm to the patient. US is the only imaging technique which can be used in field settings to assess CE prevalence because it can be run even on solar power or a small generator in remote field locations. Thanks to US classifications, the concept of stage-specific treatments was introduced and because US is repeatable, the scientific community has gained a clearer understanding of the natural history of the disease. This paper reviews the scope of US in CE, describes its strengths and weaknesses compared to other imaging techniques and its relationship with serodiagnosis and discusses sonographic features that may be helpful in differential diagnosis.