bluuebunny/crossref_metadata_2025 huggingface dataset:
Introduction
Authors: Bongrand Philippe , Gervais Julie , Payre Renaud
Published: November 2012

Résumé Cet article insiste sur le rôle des savoirs dans la construction de la frontière entre administration et politique. La dichotomie entre administration et politique subsiste alors qu’elle est mise en cause de manière récurrente, tant dans les analyses scientifiques que dans les évolutions de l’action publique. Les auteur(e)s montrent l’intérêt spécifique d’une approche centrée sur la mobilisation de savoirs pour l’action publique. Ils présentent les articles du dossier et leurs résultats relatifs aux acteurs, modalités et effets de la mobilisation de savoirs dans la construction de cette frontière.
Publier des « chiffres officiels » ou les contraintes bureaucratiques et politiques qui façonnent l'expertise d'État
Authors: Penissat Étienne
Published: November 2012

Résumé En déplaçant la focale d’analyse de l’usage des « chiffres officiels » à leur fabrication et leur publicisation, l’article contribue à une sociologie de l’expertise d’État. Il s’appuie sur l’ethnographie du service statistique du ministère du Travail. L’observation in situ des statisticiens qui rédigent ces publications permet de dégager trois types d’enjeux : la légitimation publique de leur métier, la bureaucratisation du travail d’écriture comme contrepartie du « droit à publier » et la politisation des statistiques qui, dans certains cas, peut s’opérer en lien avec l’agenda politique. Les conflits qui se nouent autour de ces enjeux invitent à ne pas réifier les frontières entre « politique » et « administration » mais à penser les différentes logiques de domination à l’œuvre dans ces institutions.
Former pour dépolitiser
Authors: Keyhani Narguesse
Published: November 2012

Résumé L’article analyse, pour les années 1975-1990, les conditions et modalités de la mobilisation de savoirs sur les relations interculturelles par le secrétariat d’État aux Travailleurs immigrés et par les organisations parapubliques sous tutelle de l’administration. Située aux marges de la Direction de la Population et des migrations, l’une d’entre elles, l’ADRI, est chargée de promouvoir un dialogue entre « Français » et « immigrés ». Elle contribue à instituer l’interaction administrative avec les immigrés comme cible de l’action publique. L’article montre que la formation aux relations interculturelles des agents des services publics est la déclinaison, en termes administratifs, du mot d’ordre du dialogue. Mais la mobilisation de ces savoirs permet également de revendiquer un territoire d’action spécifique dans un contexte de forte politisation de l’enjeu de l’insertion des immigrés. Cette revendication passe par une requalification et une dépolitisation du problème public de l’insertion.
Le marché qatari, une opportunité pour les investisseurs étrangers ?
Authors: Devaux Pascal
Published: November 2012

Résumé Après avoir investi massivement dans le développement d’une filière gazière intégrée à la fin des années quatre-vingt-dix, le Qatar est devenu le premier exportateur mondial de gaz. Dans une deuxième étape de son développement, le pays s’engage actuellement dans une politique de diversification économique qui a pour objectif de réduire sa dépendance au secteur des hydrocarbures. Un plan massif d’investissement dans le secteur des infrastructures est en cours pour faciliter le développement du secteur des services et attirer les investisseurs. Cependant, investir au Qatar reste risqué et soumis à certaines contraintes. La structure rentière de l’économie, en favorisant le secteur bancaire au détriment des marchés financiers, ne favorise pas l’investissement par l’intermédiaire des marchés. Plus déterminant, la petite taille de l’économie qatarie et sa dépendance au cycle pétrolier favorise la volatilité et la formation de bulles d’actifs. Enfin, à moyen terme, la faible productivité du travail et la forte concurrence régionale peuvent faire douter de la capacité du Qatar à se doter d’une économie diversifiée qui soit pérenne et découplée du cycle des hydrocarbures. Même si la dynamique actuelle de l’économie du Qatar est positive, celle-ci reste une économie rentière et émergente avec les contraintes et risques que cela présente pour l’investisseur.
Le gaz naturel, instrument de la stratégie de puissance qatarie
Authors: Séréni Jean-Pierre
Published: November 2012

Résumé Le Qatar, longtemps un producteur marginal de brut, est devenu en une génération le numéro un de l’industrie gazière mondiale. Il le doit moins au volume de sa production, égalée ou dépassée par les États-Unis, la Russie ou l’Iran, qu’à sa position de principal exportateur de gaz naturel liquéfié (GNL). Mais pour défendre son rang, le petit émirat doit déployer une stratégie complexe qui joue sur plusieurs registres.
Les quatre vies d'Al Jazeera
Authors: Corbucci Théo
Published: November 2012

Résumé De 1996 à nos jours, Al Jazeera a connu plusieurs vies. Celle de la naissance sur le plan médiatique international d’abord, au lendemain des attentats du 11 septembre 2001. Celle de la confirmation ensuite, avec par exemple sa couverture remarquée du conflit irakien, ou encore celle du conflit israélo-libanais de 2006. Mais entre 2007 et 2010, l’actualité dans le monde arabe se stabilise. Limitée à être « la chaîne du Proche et du Moyen-Orient » pour beaucoup de médias et de téléspectateurs, Al Jazeera atteint une période de stagnation, qui durera jusqu’à la fin de l’année 2010. C’est le « Printemps arabe » qui viendra sortir Al Jazeera de sa léthargie. Au point qu’elle se jettera dans la couverture de cet événement, littéralement corps et âme. Au risque de se voir, une fois de plus, accusée de parti pris, et de voir s’éloigner une partie de sa base, peinée de voir certaines revendications populaires passées sous silence, en particulier dans le Golfe. Ce qui a été un peu rapidement décrit comme le « moment américain » d’Al Jazeera, censé être la consécration de plus d’une quinzaine d’années de travail acharné, pourrait s’avérer être le début de la fin pour la chaîne dans le monde arabe. Mais le groupe a déjà d’autres pistes, aux quatre coins de la planète, pour tenter de sortir de cette impasse.
Studies with gel‐filled sandstone samples with implications for the origin of induced polarization
Authors: Hördt Andreas , Milde Stefanie
Published: November 2012

The origin of induced polarization (IP) in the pore space of sediments is not completely understood. Existing theories may be separated into two groups. The electrochemical polarization mechanism requires only an electrical double layer around the sediment grains, with the grain size determining the spatial scale. The membrane polarization mechanism is based on a coupling between pores of different sizes and ion mobilities to produce a frequency‐dependent conductivity. We have carried out complex electrical conductivity measurements on gel‐filled sandstone samples with different gel concentrations and fluid salinities. The idea is to reduce the ion mobility in the pore space, allowing to test hypotheses resulting from the different theories.

The conductivity spectra of the gel‐filled sandstone samples are distinctly different from those of water‐filled samples. The phase shifts decrease, the spectrum is flattened and the maximum moves towards higher frequencies. In terms of Cole‐Cole parameters, the gel decreases the chargeabilities and decay times. The effect can be clearly separated from that of increasing water salinity. We conclude that ion mobility in large pores is an important factor for the generation of the IP‐effect. Whereas the decrease in phase shift by the gel can be explained with both electrochemical and membrane polarization, the observed decrease in relaxation times seems to be inconsistent with either type of theories.
Induced polarization 3D tomography of an archaeological direct reduction slag heap
Authors: Florsch N. , Llubes M. , Téreygeol F.
Published: November 2012

Both environmentalists and archaeologists are interested in the detection and quantification of the remains of mine slag heaps from ancient smelters: possible pollution of the slag heaps and information concerning the history of the smelter's mine. Although magnetic surveys can be used to detect subsurface slag accumulations, it is not possible to derive the total amount of material from such surveys or to accurately delineate the heaps through the use of this method. Conversely, ‘Induced Polarization’ (IP) surveying allows a relevant and robust assessment of the volume of slag concentrations to be determined. In the present study, we follow up on results obtained in a previous study, carried out at the 14th Castel‐Minier mine (Ariège, France) site, where we have shown that the chargeability is proportional to the slag concentration in the ground and have used this property to perform 3D tomography of the heap. Based on a previous investigation using spectral induced polarization along a simple profile showing that the phase peak related to the slags is situated at approximately 1 Hz, in the present paper we extend our prospection to 3D by using a Terrameter SAS1000 and measuring temporal chargeability. The set of three‐dimensional data is recorded by means of classical transect measurements along parallel close profiles and is then interpreted using the RES3DINV code. Finally, archaeological and auger soundings confirmed the assessments derived from this geophysical investigation. We also briefly discuss the source of the IP signal, which we suspect to be induced by magnetite particles embedded in the slags.
Effect of Laser Pulse Fatigue on the Mechanical Characteristics of a CFRP Plate
Authors: Hong Seung Chan , Lee Jung Ryul , Chong See Yenn , Park Chan Yik
Published: November 2012

A laser ultrasonic based nondestructive evaluation (NDE) technique has been widely used in aerospace industries for inspecting parts and structures made of composite materials. The thermoelastic regime is used for the ultrasonic generation, so no plasma is formed on the surface of composite structure. Generally, the service lifetime for an aircraft could be more than 25 years. Thus, the composite structures of the aircraft could be susceptible to laser pulse fatigue damage caused by the laser pulse energy of a laser ultrasonic generator in the long-term periodic maintenance inspection. In this paper, the effect of laser pulse fatigue on the mechanical characteristics of a carbon-fiber-reinforced polymer (CFRP) plate (USN175BX Carbon UD preprag) with the stacking sequence of [0/45/-45/90]s is investigated to verify the reliability of the use of a laser ultrasonic based NDE technique on the CFRP plate specimen inspection. A high-speed laser ultrasonic scanning system (400mm/s at the intervals of 0.4 mm) was setup to perform repeat scanning of 1300 times on a CFRP plate specimen with the scanning area of 70 mm x 60 mm. These repeat scanning times were set in consideration of the periodic maintenance inspection scheduled to be 1 time/week x 52 weeks/year x 25 years. A 532nm Q-switched continuous wave laser (QL) was used and set at the laser pulse energy levels of 0.6 mJ and 1.2 mJ. Lamb wave assessment based on pitch-catch method was proposed in this paper to monitor the mechanical characteristics of a composite specimen. In each completion of 100 times repeat scanning, the Young’s modulus of the scanning area was evaluated based on the group velocity of S0 Lamb wave mode. In addition, the surface condition of the scanning area was investigated by using a microscope.
Buckling Analysis of Ring-Stiffened Laminated Composite Cylindrical Shells by Fourier-Expansion Based Differential Quadrature Method
Authors: Barani Saeed , Poorveis Davood , Moradi Shapoor
Published: November 2012

This article focuses on the application of the Fourier-expansion based differential quadrature method (FDQM) for the buckling analysis of ring-stiffened composite laminated cylindrical shells. Displacements and rotations are expressed in terms of Fourier series expansions in longitudinal direction and their first order derivatives are approximated with FDQM in circumferential direction. The 'smeared stiffener' approach is adopted for the stiffeners modeling. Two FORTRAN programs prepared for linear and nonlinear analysis and results were compared by ABAQUS finite element software. Buckling loads of stiffened and unstiffened shells considering the effects of changes in shell and stiffener geometric and material properties and also shell lay-ups are investigated.
Fatigue Damage Mechanism of Titanium in Inert Environments
Authors: Zahari Nur Ismarrubie , Yussof H. , Sugano M.
Published: November 2012

The fatigue damage of titanium has been studied on thin plate specimens subjected to alternating plane bending in argon gas. Fatigue strength in argon gas at Nf = 108 cycles was obtained to be 102 MPa. Fatigue behavior of titanium in argon gas has been attributed to the degradation of grain boundary cohesion with argon gas atoms/molecules. Fatigue cracks were propagated partly in intergranular mode. It has been plausible that argon gas atoms/molecules could penetrate into the distorted regions close to grain boundary through lattice defects and degrade grain boundary cohesion. Grain boundaries have been preferentially damaged in argon gas. The results in argon gas have been compared with those obtained in vacuum and in air.
Effect of Rotor Tip Gap Variation at the Rear Stages of an Axial Flow Compressor
Authors: Pradeep A.M. , Chiranthan R.N. , Dutta Debarshi , Roy Bhaskar
Published: November 2012

In this paper, detailed analysis of the tip flow of an axial compressor rotor blade has been carried out using the commercial CFD package ANSYS CFX. The rotor blade was designed such that it is reminiscent of the rear stages of a multi-stage axial compressor. The effects of varying tip gaps are studied using CFD simulations for overall pressure rise and flow physics of the tip flow at the design point and near the peak pressure point. Rig tests of a low speed research compressor rotor with 3% tip clearance provided characteristics plots for validation of the CFD results. With increase in clearance from 1% to 4%, the rotor pressure rise at the design point was observed to decrease linearly. Increase in the clearance increases the cross flow across the tip; however, the magnitude of the average jet velocity crossing the tip decreases. The tip leakage vortex was observed to stay close to the suction surface with increase in clearance.
Impact of Operating and Health Conditions on a Helicopter Turbo-Shaft Hot Section Component Using Creep Factor
Authors: Abdul Ghafir Mohammad Fahmi , Li Yi Guang , Wahab A.A. , Mohd Yunos Siti Nur Mariani , Yaakub M.F. , Salleh Siti Juita Mastura Mohd , Kamarudin Qamarul Ezani , Masrom Mohd Fikri Mohd
Published: November 2012

The paper investigates the effects of various gas turbine operating and health conditions on its hot section component’s creep life via a simple relative creep life parameter known as Creep Factor. Using the Creep Factor, the correlation between individual gas turbine operating and health parameter and component’s creep life was established and the weight of the impact was measured. Analytical-parametric-based creep life estimation model combined with the Creep Factor approach was developed and integrated with an existing engine performance model to allow the estimation of various hot section component creep lives and the computation of the Creep Factors. The impact analysis was carried out on the high pressure turbine blade of a model turbo-shaft helicopter engine. The results indicate that for a clean engine, the change in engine rotational speed was seen to provide the highest impact on changing the blade’s creep life consumption while for a degraded engine, the presence of compressor fouling has the highest threat in changing the blade’s creep life. The analysis also shows that the Creep Factor is a good indicator of creep life consumption and provides a good technique to rank the influencing factor according to the threat they imposed.
Preliminary Development of Electric Motorcycle Engine for Sport Aviation Vehicles
Authors: Jamil Mohd Khairuladha , Kadir Mohd Ezwani , Zainol Mohamad Zikri , Abdullah Abu Hanifah , Bakar Abu Zaid
Published: November 2012

Flying activities of sport aviation vehicles normally use Internal Combustion Engines (ICE) for their powerplant, which emits Carbon Dioxide (CO2) and also produces noise. Environmental issues regarding harmful gas emission and noise may restrict the sport aviation activities and resulting in reduction of interest in flying as a sport activity. The feasible solution for this issue is by replacing the Internal Combustion Engines (ICE) with Electric Engines on all sport flying vehicles. The Modenas CTric Electric Engines was tested to measure the parameters required by comparable Internal Combustion Engine used by sport aviation flyers. Other parameters; engine endurance, temperature and performance, were also tested. The bench test was conducted using specially design test rig. The results show that there is a possibility for the Modenas CTric Motorcycles Electric Engine used as an alternate source of powerplant for paramotors and microlight aircraft. However, there is penalty on the vehicle payloads due to weight of the battery. Lighter battery technology integration is to be developed to reduce the weight of the flight vehicles. This study serves as a platform for further work in electric engine technology for commercial aircraft application. Availability of green engine (no emission and noise output) will generate more interest in sport aviation activities and prepare for the future commercial Electric Engine aircraft application.
Ventilated Brake Disk Air Streamlining Using Curved Vane
Authors: Munisamy Kannan M. , Yusoff Mohd Zamri , Thangaraju Savithry K.
Published: November 2012

The past research by the author on the conventional brake disk design i.e. straight blade bi-directional design, a misalignment of flow was identified. The misalignment was quantified using CFD as design tool. In the effort of re-aligning the flow angle helical lines fitted onto the conventional inner and outer diameter disk brakes yielded two different design innovation. The two “curved” designs have highlighted tremendous improvement on flow characteristics. Experimental analysis is carried out on the two curved 1 and curved 2 prototypes. The quantitative mass flow rate result is compared for conventional and the two curve shaped brake disk. Then, the data is fed as input condition to Computational Fluid Dynamics (CFD) model for disk brake models to analysis the flow characteristics qualitatively. The aerodynamics visualization through CFD supports well the mass flow improvement. The non-dimensional flow number is established and the correlation between flow number and Reynolds number is highlighted.
Thermodynamic Analysis of Flow Field at the End of Combustor Simulator
Authors: Ehsan Kianpour , Sidik Nor Azwadi Che , Bozorg Mohsen Agha Seyyed Mirza
Published: November 2012

This study was carried out to investigate the effects of different cooling holes configurations on the thermal field characteristics inside a combustor simulator. In this research, a three-dimensional presentation of a true Pratt and Whitney aero-engine was simulated and analyzed. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the stream wise direction and aligned in the span wise direction. The findings of the study indicate that the thickness of the film-cooling layer was thicker for the greater penetration depth. Furthermore, for the combustor simulator with more cooling holes, the temperature near the wall and between the jets was slightly increased. Also at the leading edge of the jet, the gradients of temperature were quite high at the jet-mainstream interface.
Aircraft Dynamically Similar Model Design Using Simulated Annealing
Authors: Shakoori Ali , Mortazavi Mahdi , Nobahari Hadi
Published: November 2012

A new methodology has been proposed to design a dynamically similar/scaled model (DSM) of aircraft. This method uses the simulated annealing (SA) optimization algorithm to get the maximum similarity between model and full-scale aircraft with help of systems movement and using minimum ballast weight. For the ½ model of an unmanned aerial vehicle (UAV), internal arrangement is designed to achieve the desired model center of gravity position and moments of inertia. A computer code is developed, and model suitable arrangement is obtained. Results show that the proposed optimization approach to design of DSM was successfully used to find adequate model systems arrangement and minimizing ballast weight to access more capacities for data-acquisition systems or fuels. In this problem, ballast weight reduced about 0.6 kgf for a 55 kgf model, in addition of simplicity of DSM design for various configuration and flight regimes.
Automatic Monitoring of Photovoltaic Cells Performance on Solar Aircraft
Authors: Sahwee Zulhilmy , Husain Halil , Kadir Muhd Khairulzaman Abdul , Razali Mohamad Fiteri , Zainol Mohamad Zikri , Sarmin Shahliza Azreen
Published: November 2012

The development towards the usage of green energy sources is currently a major concern in today’s lifestyle due to the limited supply of fossil-based energy. Many have turned to alternative energy resources that are less polluting to the environment. Replacement of the vehicle’s fuel-based engine to an electric-based engine by using alternative or hybrid energy is one of the possible paths that many studies are conducted. In the aviation field, harvesting solar energy by using solar panel to charge aircraft on-board batteries could reduce the dependency on fuel. As with any other energy conversion technology, the solar panel performance needs to be monitored so that the power output can always be maintained at maximum available power. This paper presents a research and development of a system to monitor the health of photovoltaic panel installed on aircraft by measuring its voltage and current. The measurement is conducted using low power microcontroller. The system is capable to automatically measure the output of every solar panel installed in the system by connecting them with a matched load during the measurement process. The power output is then compared to the initial values prior to installation to determine how much power is currently being generated. By knowing the actual power output of each solar panel, less efficient or defective panel can be identified and replaced during maintenance. The system can be implemented not only for an aircraft but also applicable to other system that uses solar panel as their energy resources.
Investigation on the Effect of Airspeed and Altitude to Phugoid Mode of a Small Unmanned Blended Wing-Body Aircraft with Canard as a Longitudinal Control Surface
Authors: Nasir Rizal E.M. , Kuntjoro Wahyu , Wisnoe Wirachman
Published: November 2012

Phugoid mode is a lowly damped, low-frequency oscillatory motion representing vertical translation usually related to kinetic and potential energy interchange. MIL-F-8785C standard has ruled out qualitative specification requirements on measurement of flying and handling qualities of piloted aircraft. For phugoid mode, these requirements lie in the value of its damping ratio. Small aircraft is sensitive to atmospheric conditions and poor phugoid mode performance is observed in many unmanned aircraft. This paper discusses the effect of airspeed and altitude to phugoid mode of small, unmanned blended wing-body (BWB) aircraft named Baseline-II E-2. Baseline-II is a low subsonic, remotely-piloted UAV used to study the behaviour of a BWB-type aircraft. The case presented here is an E-2 version in which a specifically-designed canard is incorporated as its longitudinal control surface. Five Category B flight cases (airspeeds) per altitude-case, and three altitude cases (low, medium and high) are studied. Model-N dynamic model is introduced here to become the basis of flight simulation. The model is compared to models derived by other authors and approximation equations. The mean of simulating phugoid behaviour is using state-space representation of the aircraft using Matlab SIMULINK. The computations show that Baseline-II E-2 undamped natural frequency of phugoid mode is inversely-proportional to airspeed and reduces as altitude increases. These have adverse effect on its damping ratio that increases near parabolically when the aircraft flies faster, and reduces when it climbs up. The cause of these trends is looked into in detail and issues concerning Baseline-II E-2’s unsatisfactory and unstable phugoid mode oscillation at low speed are addressed.
Three Dimensional Path Planning Algorithm for Small UAVs Incorporating Existing Dynamic Soaring Heuristics
Authors: Ariff Omar Kassim , Go Tiauw Hiong , Wiriadidjaja Surjatin , Zhahir Amzari
Published: November 2012

An area under consideration of improving the mission effectiveness of small-scale, autonomous Uninhabited Aerial Vehicles (UAVs) has been the increase of speed. One method is to incorporate dynamic slope soaring maneuvers as part of the flight path during waypoint navigation. Research into autonomous dynamic soaring capability in small-scale UAVs began with selecting a suitable maneuver heuristic. The output from the heuristic model has then been used to formulate a non-iterative trajectory forming algorithm. By utilizing Dubin’s curves, a viable trajectory can be generated between the exit point of the dynamic soaring maneuver and the next waypoint. The result is a complete, easily implemented three-dimensional autonomous dynamic soaring capability.
Spray Characteristics of Swirl Effervescent Injector in Rocket Application: A Review
Authors: Ghaffar Zulkifli Abdul , Hamid Ahmad Hussein Abdul , Rashid Mohd Syazwan Firdaus Mat
Published: November 2012

Injector is one of the vital devices in liquid rocket engine (LRE) as small changes in its configurations and design can result in significantly different LRE performance. Characteristics of spray such as spray cone angle, breakup length and Sauter mean diameter (SMD) are examples of crucial parameters that play the important role in the performance of liquid propellant rocket engine. Wider spray cone angle is beneficial for widespread of fuel in the combustion chamber for fast quiet ignition and a shorter breakup length provides shorter combustion chamber to be utilized and small SMD will result in fast and clean combustion. There are several mechanisms of liquid atomization such as swirling, e.g. jet swirl atomization or introducing bubbles into the liquid and effervescent atomization. Introducing a swirl component in the flow can enhance the propellant atomization and mixing whereas introducing bubbling gas directly into the liquid stream inside the injector leads to finer sprays even at lower injection pressures. This paper reviews the influence of both operating conditions and injector internal geometries towards the spray characteristics of swirl effervescent injectors. Operating conditions reviewed are injection pressure and gas-to-liquid ratio (GLR), while the injector internal geometries reviewed are limited to swirler geometry, mixing chamber diameter (dc), mixing chamber length (lc), aeration hole diameter (da), discharge orifice diameter (do) and discharge orifice length (lo).
Comparison between H2 and H∞ Optimal Control Solutions for a Combined Energy and Attitude Control System
Authors: Siang Ban Ying , Varatharajoo Renuganth
Published: November 2012

The paper focuses on applying optimal control solutions to combined energy storage and attitude control system (CEACS) under different reference missions. In previous researches, the proportional-integral-derivative (PID) control method, the PID-active force control method and H2 control were tested for CEACS and achieved its mission requirement. However, problems such as the in-orbit system uncertainties affect the PID control performances. Thus, two optimal control methods, H2 and H∞ controls are proposed and tested on CEACS under different mission scenarios to improve its pitch attitude accuracy. Results show that both H2 and H∞ are able to achieve the reference mission requirement even under the influence of uncertainties (non-ideal). Moreover comparison between H2 and H∞ shows the H2 is a better control option for CEACS in terms of disturbance rejection.
Remote Sensing Data Derived Parameters and its Use in Landslide Susceptibility Assessment Using Shannon’s Entropy and GIS
Authors: Pourghasemi Hamid Reza , Pradhan Biswajeet , Gokceoglu Candan
Published: November 2012

In recent years, the growth of urban populations in hazardous areas has increased the impact of natural disasters in both developed and developing countries. The purpose of the current study is to assess the landslide susceptibility in Kalaleh township of Golestan province, Iran. In this study the Shannon’s entropy approach was applied. A total of 82 landslide locations were identified primarily from aerial photographs and field surveys. Then eighteen landslides conditioning factors were prepared in GIS. These landslide conditioning factors are: slope degree, slope aspect, altitude, plan curvature, profile curvature, tangential curvature, surface area ratio (SAR), lithology, land use, soil texture, distance from faults, distance from rivers, distance from roads, fault density, road density, topographic wetness index (TWI), stream power index (SPI), and sediment transport index (STI). Using these conditioning factors, landslide susceptibility index was calculated using Shannon’s entropy. For model validation, the results of the analyses were then compared with the field-verified landslide locations. Additionally, the receiver operating characteristics (ROC) curves for landslide susceptibility maps were drawn and the area under curve values was calculated. Verification results showed 82.15% accuracy. According to the results of the AUC (area under curve) evaluation, the map produced exhibits satisfactory properties.
RVSM Implementation in Malaysia
Authors: Nusyirwan Istas F. , Perumah Kannan
Published: November 2012

This paper addresses the current scenario of air traffic over Malaysian airspace and its impact on existing routes and capacity. In dealing with the increase of capacity, ICAO has embarked on implementing several new measures that would accommodate more aircrafts and the same time maintaining the highest level of safety. Those measures are outlined in ICAO’s Doc 9574 and 9937. Instead of introducing more routes, which up to one point could reach its maximum saturation point, ICAO has introduced Reduced Vertical Separation Minima (RVSM). RVSM increases the number of aircraft that can be accommodated on the given route. The Malaysian airspace is strategically located in the middle of the Westbound and Eastbound routes over the Asia Pacific region. This is an added advantage for the installation the Height Monitoring Unit for RVSM performance of aircraft. Generally, almost all of the aircraft overflying Malaysian airspace are already at their optimum flight levels. This paper uses the trend for year 2010 and 2011 data provided by the Department of Civil Aviation of Malaysia in the analysis. The paper analyses the current scenario of air traffic safety over Malaysian airspace and identifies suggestions to develop a system that could extract information from ADS-B for height monitoring purposes.
Short-Term and Long-Term Feedstock Bio Jet Fuel for Green Environment of Air Transport in Climate Change Awareness
Authors: Mohd Noh Hazariah , Md Zulkifly Nurul Ain
Published: November 2012

Air transportation and manageable cost is the key to determine the smooth running of the airlines. Today, the trend is changing with the environment generally and sustainability standards specifically. Responsibility towards environmental issues, in conjunction with safety and security, remains an essential promise for the aviation industry, even in the face of the economic downturn. IATA’s vision is for carbon-neutral growth on the way to a zero-emission future. This is being implemented through IATA’s four-pillar strategy: investing in technology, flying planes effectively, building efficient infrastructure and using positive economic measures (technology, operations, infrastructure and economic instruments). This paper will focus in the projection on biofuel as an alternative energy compromise reduction in carbon dioxide (CO2) emission in overview through short-term and long-term feedstock biomass. As environmental concerns are becoming clearer in general transportation systems, air transportation generates for its presence which must be considered in strategic planning development for the bio jet fuel to be implemented in near future in air transport operations for tenable greener skies.
Coupled Analytical-Numerical Procedure to Solve the Double Wedge Spiked Supersonic Intake Flow Field
Authors: Al-Kayiem Hussain Hamoud , Salih Tawfeeq W. , Govindasamy Dhinakaran
Published: November 2012

Designers of the aero engines are in quest of maintaining the pressure as high as possible at the face of the compressor, with air velocity not higher than 0.8 Mach. Reduction of the flow from supersonic to such speed is combined with pressure reduction. This paper presents results from coupled techniques to solve for the flow field of double wedge spiked supersonic intake. The selected spike has 4° forebody wedge angle and the second ramp angle is 8°. The external part of the flow was solved analytically while the internal part was solved numerically by finite volume technique. The analysis was carried out at different Mach numbers (1.4, 1.8, 2.2, 2.4, and 3) and different angles of attack (0°, 6°, and 12°). The procedure is validated and the results are presented in terms of the pressure recovery at the face of the compressor. The results have shown that generally the pressure recovery decreases by increasing of incidence angle. The non-zero incidence was found to produce noticeable difference in pressure distribution at the face of the compressor. This became considerably effective at incidences leading to detached shocks at the leading edge of the spike.
Numerical Sensitivity Analysis of Axial Flow Fan 3D Aerodynamics under Off Design Conditions
Authors: Akula Praveen Kumar , Singh Balbir , Nair Vishnu G.
Published: November 2012

Compressor is a crucial component of an engine. Flow through the compressor is intricate and sensitive to the reference frame, geometry of the blade, tip clearance, stator, staging etc. Compressor, though designed for a particular environment, is also expected to show its performance under off design conditions like accelerating flight, landing, take off, climbing etc. The flow in third dimension leads to many complications and ambiguity. Tip aerodynamics, passage flow, and vortex aerodynamics play crucial role in describing the flow through the upper half of the blade and in the tip region, whereas flow over blade surface, trailing edge and the hub will guide the aerodynamic behavior of the rotor blade. This exercise is done for off design environment to study the aforesaid flow characteristics and is carried on an axial flow fan. The performance variation of fan flow under varying flow conditions is analyzed.
Studies on Dynamic Response of Subway Tunnels with Initial Defect under Long-Term Train Loads
Authors: Dong Fei , Dong Jun , Sun Wei Ze
Published: November 2012

Based on the background of a subway construction project, deterioration characteristics of the existed subway tunnels under long-term train loads is studied by using the method of stiffness discount which could reflect fatigue damage of the structure. Firstly, dynamic response of the tunnel with initial defects caused by approaching construction under long-term train loads is analyzed according numerical simulation, and some results under different degrees of fatigue are obtained. Then, numerical results of acceleration responses at such different points as the upper vault, the side wall and the bottom of tunnels in two directions, are compared with each other while the train loads are applied at the left tunnel, especially under three different stiffness. Our investigation shows local structural damage in the position with initial cracks will be caused by a high cycle stress although there are fewer influences of stiffness changes on dynamic response of tunnels.
Numerical Simulation of Pile-Soil Interaction Considering Sand Liquefaction under Earthquake
Authors: Li Pei Zhen , Ma Dong Ya , Zeng Da Ming , Lu Xi Lin
Published: November 2012

Liquefaction is one of the most important damages in pile foundation under earthquake. However, it is very difficult to analyze. Numerical simulation of pile-soil interaction considering saturated sand liquefaction under earthquake is conducted using OpenSees program. In this model, the soil is divided into soft clay soil and saturated sand, and the single pile is embedded in the soil. The results show that the pore water pressure rises and the soil liquefied as vibration time increases. With the nonlinear of the soil develop, the stiffness, bearing capacity and the acceleration response of the soil and the pile decrease, while the displacement response of the soil increases. Therefore, it is necessary to consider the soil liquefaction in the design and analysis in the engineering practice.
Numerical Simulation for Progressive Collapse and Protection of a Multi-Storey Building due to an Explosion in its Basement
Authors: Tian Li , Li Zai Long
Published: November 2012

The progressive collapse of a multi-story building and its protective effect with aluminum foam under an explosion in its basement are numerically investigated in this paper. The three-dimensional coupling model composed of a multi-story frame structure with a basement and the surround soil is modeled using ANSYS/LS-DYNA. The progressive collapse of the entire structure under explosive impact and the protective effect of the aluminum foam are simulated using the proposed three-stage simulation method (TSSM). The result shows that, the aluminum foam as a protective layer can reduce the impact effects very well, and then can prevent progressive collapse effectively. The same model is also simulated by direct simulation method (DSM) and alternative load path method (ALPM). By comparison with the two methods, the TSSM is illustrated practical, accurate and economic for the analysis of progressive collapse.
Numerical Analysis for Progressive Collapse and Protection of Underground Structure under Internal Blast Load
Authors: Tian Li , Wang Qi
Published: November 2012

Dynamic response of an underground structure with the protection of foamed aluminum under internal blast load, compared with that without any protection, has been investigated numerically in this paper. The three dimensional model of the two-storey and two-span underground structure covered with soil around was built with the explicit dynamic analytical software LS-DYNA. The three-stage simulation method （TSSM） is proposed. And the middle column of the structure is covered with foamed aluminum which provides a better protection for the column under the blast load. The solid-fluid interaction algorithm, the erosion algorithm and the stress initialization method are employed in the calculation. It is found that, under the protection of foamed aluminum the collapse resistance of the structure has been improved greatly compared with the structure without any protection.
Experimental Study on Shear Behavior of Prestressed Concrete Beams
Authors: Wang Guo Lin , Ding Wen Sheng
Published: November 2012

Two simply supported beams with a shear span to depth ratio of 2.2 were tested, one with straight prestresssing tendons and the other without for reference. The shear behavior and the prestressing effect are focused on. The test results showed that the prestressed concrete (PC) beam has a significant arch effect, and the prestressing could greatly increase both the cracking load and the shear strength. Besides, the Modified Strut-and-Tie Model (MSTM) and the sectional design method from China Code (GB10) and ACI318-08 have also been adopted for predictions. The comparisons indicates that the MSTM can not only well predict the shear strengths of PC beams with a small shear span to depth ratio, but also well account for the prestressing effect, while the sectional design method seems so conservative due to its not properly considering the shear mechanism of such beams. It can be concluded that the MSTM is capable of predicting the shear strength of PC beams with significant arch effect and thus can be employed in practical designs.
A Research on the Influence of Vessel-Propeller Coupling Effect to Shaft’s Lateral Vibration
Authors: Zhu Jun Chao , Zhu Han Hua , Yan Xin Ping , Jiang Ping
Published: November 2012

The aft part of large scale vessel propulsion shaft is a cantilever with a propeller. As the shaft doing the lateral vibration, the trail of propeller shaft center-line, which appears together with the movement, is the cone surface with the shaft center as the symmetrical axis, at the same time the propeller will vibrate with the shaft. In order to investigate the influence of propeller effect to shaft lateral vibration, the main work in the paper includes modeling the finite element of a large scale vessel propulsion shaft, studying the factors of water mass adhered to propeller, pin softening and gyroscopic moment to the shaft lateral vibration. The calculation shows that: if the propeller's gyroscopic moment is positive, the free frequency of shaft will increase, while added water mass and spin softening will obviously decrease the free vibration frequency of shaft.
Statistics and Analysis of Typhoons Landing and Failure Mechanism of Coastal Low-Rise Buildings in China
Authors: Dai Yi Min , Yan Xu Guang , Wang Xiang Jun , Sun Hong Xin , Li Yong Gui
Published: November 2012

In order to reveal the status of typhoon landfall in China coastal areas, the coastal areas and frequency of typhoon landing were compared with the statistical analysis in the paper for nearly 50 years; combined with the wind pressure of low-rise buildings under typhoon in China's coastal, structures damage of low-rise buildings were investigated. The results show that, the southwest coast of Guangdong landfall the largest number of typhoon landing, while the coastal areas of Fujian and Zhejiang have larger number of strong typhoons; turbulence great impact on surface air pressure; It was also found that the high suction pressure zones occurred around the windward roof edges at a wind azimuth of 450,and wind pressure along the roof corner just behind the roof ridge. The results of the present study are expected to be useful for the future development of a simple approximate formula for the low-rise buildings of the coastal area for design use.
Study on Influence of Infilled Wall of RC Frame Structures
Authors: Liu Yan Na , Wang Li Bo , Zhang Yong Sheng
Published: November 2012

Based on the simulation of a eight-storey reinforced concrete(RC) frame, study has been carried out considering the rigid effect of infilled wall to explore the effect of masonry infilled on the framework by the difference of its quantity . MIDAS structural analysis software is used to make modal analysis and response spectrum analysis for the finite element models. In current chinese specification, infilled wall is often considered as nonstructual components in the buildings regardless load-supporting and shear-resistant action while the impact of rigid effect of infilled wall is not properly considered simply with the method of the reduction of structures’ vibration period. In this paper, a comparison to the current code was also made to get a better understanding of the difference between these two approaches.
Seismic Behavior Analysis and Earthquake Damage Prediction of Buildings in Langfang
Authors: Li Qiao Yan , Zhao Pei Pei , Xu Guo Dong
Published: November 2012

Ascertaining existing buildings of seismic capacity deficiency is the precondition of strengthening them, which is very important to reduce earthquake disaster in the future. So it is necessary to predict the seismic damage of buildings. This article is the results of earthquake disaster prediction in urban area of Langfang, which is expected to provide a theoretical basis for the buildings in Langfang to defense the earthquake disaster.
Behavior of New Type of Semi-Rigid Joints under Moment and Tensional Force
Authors: Xu Man , Gao Shan , Wang Yu Yin
Published: November 2012

In the system of preventing progressive collapse, the joints always play a key role in catenary action and alternate load path while the joints are usually under the combination of bending moment and tensional force. In this combination, high rotation capacity and good resistance of joints are demanded. In this paper, a new type of semi-rigid joint used in the structures with concrete-filled square steel tube (CFST) columns is proposed and developed by ABAQUS. The new type joint is suitable for the classification for semi-rigid connection; The bending moment resistance of the joint decreases linearly with the increase of tensional force; reducing pretension force reasonably is beneficial for the tensional force to develop “catenary action”; the width of short leg of angle would influence the moment resistance of the joint evidently; the initial rotation stiffness is not affected by width of leg dramatically.
Quasi-Static Analysis of Stiffened Plate under Axial Pressure
Authors: Ji Guo Ming , Sun Gang , Zhang Gen Yuan
Published: November 2012

Quasi-static analysis is of a simulation of static problem with motion analysis which restricting the load velocity so that the outcome we got can only have a little inertia influence which we can neglect. In order to solving stability problem of stiffened plate under axial pressure, we adopt this quasi-static analysis which applying displacement on structure. In pro-buckling, compared to the static analysis, quasi-static analysis can get the structure responses accurately with less time cost; In post-buckling, quasi-static analysis can get the structure responses which static analysis can’t get. With this we provide a new method in static problem
Structural Safety Monitoring during Retrofit of Shanghai Expo Puxi Entertainment Hall
Authors: Zhao Ming , Liao Jun
Published: November 2012

Shanghai Expo Puxi Entertainment Hall is reconstructed based on existing workshop building. To meet new function requirements of the hall, a structural column is removed and replaced with a jacking beam. A structural safety monitoring system is proposed and applied to evaluate the real-time structural state and ensure the structural safety. Vibrating wire sensors and FBG sensors are installed to monitor the stress of member of the space truss structure; ForesightTM series DSTS (Distributed Strain and Temperature Sensors) is installed to monitor the stress of the jacking beam. Results show that the structural safety monitoring system works stably. The safety monitoring system reflects the real-time behavior of the structure and controls the structural reconstruction safety effectively.
A Structural Damage Alarm Index Based on the Statistical Probability of Abnormal Frequency Offset
Authors: Song Yan Sheng , Sun Zong Guang , Sun Li Ye
Published: November 2012

Based on the statistical probability of abnormal frequency offset, this paper puts forward a new structural damage alarm index. Demonstrating the feasibility of corresponding structural damage alarming method, this article introduces the index to analize a steel frame structure in frequency domain. The results show the abnormal index defined in sense of statistics indicates the abnormity of corresponding test cases clearly.