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AT the present time it is a general practice to make extensive investigations of the flutter and oscillatory stability characteristics of all prototype aircraft at an early stage in the design. So far as theoretical investigations of these characteristics are concerned there is often considerable uncertainty as to the values of the aerodynamic coefficients to be used, for there is evidence that measured and theoretical coefficients may differ considerably. Measured values of the coefficients are therefore required both for direct use in calculations and as a check on the theoretical coefficients, and also to provide a guide in the development of more precise theories. Unfortunately the wide variations in wing plan forms and the rapid increase in flight speeds which have occurred in recent years have meant that experimental work in this particular field has not kept pace with development and the designer is faced with the problem of ensuring the safety and operational efficiency of his aircraft using theoretical coefficients whose values may be unreliable.

This research aims to investigate the effects of manipulation of a torpedo’s geometries to attain higher terminal velocity. The parameters of interest include geometric changes of the original design, as well as sea water properties that reflect water depth in South China Sea.

The research make use of computational fluid dynamics (CFD) software, FLUENT, to solve viscous incompressible Navier–Stokes equations with two equations k-epsilon turbulent model. The calculated drag coefficient is subsequently used to calculate the maximum attainable terminal velocity of the torpedo.

It was found that the terminal velocity can be improved by sharper tip angle, greater aspect ratio, greater diameter ratio and optimum rear angle at 30°. Sensitivity of drag coefficient toward each of the parameters is established in this paper.

The paper, in addition to verifying the importance of aspect ratio, has also established the tip angle, diameter ratio and rear angle of the torpedo as important geometric aspects that could be tuned to improve its terminal velocity.

The purpose of this paper is to present the results of experimental and theoretical studies on the flexural capacity of reinforced concrete (RC) beams strengthened using externally bonded bi-directional glass fibre reinforced polymer (GFRP) composites and different end anchorage systems.

A series of nine RC beams with a length of 1,600 mm and a cross-section of 200 mm depth and 100 mm width were prepared and externally strengthened in flexure with bi-directional GFRP composites. These strengthened beams were anchored with three different end anchorage systems namely closed GFRP wraps, GFRP U-wraps and mechanical anchors. All these beams were tested with four-point bending system up to failure. The experimental results are compared with the theoretical results obtained using the relevant design guidelines.

The experimental results demonstrate a significant increase in the flexural performance of the GFRP strengthened beams with regard to the ultimate load carrying capacity and stiffness. The results also show that GFRP strengthened beams without end anchorages experienced intermediate concrete debonding failure at the GFRP plate end, whereas all the GFRP strengthened beams with different end anchorage systems failed in rupture of GFRP with concrete crushing. The theoretical results revealed no significant difference among the relevant design guidelines with regard to the predicted ultimate moment capacities of the bi-directional GFRP strengthened RC beams. However, the results show that ACI Committee 440 Report (2008) design recommendation provides reasonably acceptable predictions for the ultimate moment capacities of the tested beams strengthened externally with bi-directional GFRP reinforcement followed by FIB Bulletin 14 (2001) and eventually by JSCE (1997).

The research work presented in this manuscript is authentic and could contribute to the understanding of the overall behaviour of RC beams strengthened with FRP and different end anchorage systems under flexural loading.

The purpose of this study is to evaluate the role of encapsulation pH and iron source on the anchorage mode and performance of iron oxide-encapsulated aluminium pigments.

The coloured waterborne aluminium pigments were prepared at pH 5-7.5 by using FeSO₄ and FeCl₃ as iron source. The anchorage mode of iron oxides on aluminium was characterized using optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Furthermore, the pigmentary performance was characterized through anticorrosion test and multi-angle spectroscopy.

Diaspore and boehmite could form from H₂O₂ oxidizing aluminium. Both low pH and FeSO₄ systems are beneficial for diaspore, inducing green rust anchor on the aluminium to form goethite. Either in FeSO₄ or FeCl₃ system, slightly high pH is beneficial for the formation of boehmite, which occurred together with ferrihydrite to form denser coating with yellowness and excellent anticorrosion property. At pH above 7, the formation of dendritic iron oxide is detrimental to the anticorrosion property and the glossiness.

Only FeSO₄·7H₂O and FeCl₃·6H₂O as iron sources were explored.

The investigation results provide theoretical basis to obtain excellent chromatic waterborne aluminium pigments.

The method for investigation of encapsulation mechanism by surveying the structure of iron oxides on aluminium, which varies with the pH of the system and iron sources, is novel.

To solve the reinforcement congestion, mechanical anchorage is increasingly popular in use instead of conventional hook rebar. However, the bond performance between the rebar and concrete and the range of stress transfer between the two are still not well understood. The purpose of this study is to study the bond performance and failure mechanisms between reinforcement and concrete around an anchorage zone in a structural element.

In this study, simulations were carried out by 3D RBSM (Rigid Body Spring Model). This approach divided a problem of interest into elements, namely concrete and steel elements. And to simulate the failure of anchorage of RC, the steel element size is set according to the geometry complexity of the reinforcing bar. By using this method, two simulation cases of anchorage failure were carried out.

This paper shows that simulations demonstrated good agreement with experimental data in terms of anchorage capacity, crack pattern, and failure mode. This indicates that RBSM analysis can simulate the failure behavior governed by complex cracks.

This paper indicates the analytical approach to investigate the anchorage performance of RC.

Anchorage with concrete bearing pad is commonly used in Iran for stabilization of excavations because of the ease of construction, less costs and less time consumption than the soldier pile method. In this method, a wall facing which includes the concrete bearing pads at the location of the anchors and a shotcrete layer between the bearing pads is constructed parallel to the excavation operation similar to the nailing method.

In this paper, using the finite element software Abaqus, a three-dimensional model of the above-mentioned type of wall is constructed, and the effect of spacing and size of bearing pads on the wall behavior is discussed.

According to the obtained results, the size of the concrete bearing pads has little effect on wall deformations, but the internal forces and bending moments developed in the shotcrete layer between the bearing pads are greatly influenced by the bearing pads dimensions and spacing.

Owing to the discrete elements of the wall facing, the behavior of this system is completely three-dimensional.

Fibre reinforced polymer (FRP) materials are currently used for concrete structures in areas where corrosion problems are serious. Recent applications of FRP rebars in normal reinforced concrete structures in fact cannot fully utilise the strength of FRP. A more rational use of FRP would be in the area of prestressed concrete (PC) structures. In spite of the superb strength provision of FRP tendons over steel tendons, use of FRP PC members is often questioned by practising design engineers. This is largely due to the brittleness of FRP tendons and lack of ductility in FRP RC structures. Recent research has demonstrated some important findings in promoting the confidence of adopting FRP RC beams. This paper reviews some recent work on the use of FRP in PC structures. Future possible research areas are also highlighted.

The purpose of this article is to help acquaint librarians with some of the major resources that are available regarding the Alaska Native Claims Settlement Act and the National Interest Lands.

This paper aims to present a case study of some current disorders affecting the stone‐panels of façade claddings, i.e. cracking, spalling close to anchorage systems and staining. The purpose of this study is to identify the origin of the mechanical and chemical disorders of the carbonate rock thin panels of the “Les Chênes 1” building of the University of Cergy‐Pontoise (France).

Mapping of the disorders, anchorage system investigation at spallings, chemical analyses of oil‐like stains were performed in order to characterize both disorders. Porosity and capillarity properties of the rock were measured and compared between samples collected outside and within a stain.

Mechanical disorders result from vandalism or poor implementation. Spallings are disorders very likely in evolution. Their occurrence may increase through time. Stains are made of silicone destabilization products.

A model is proposed for the formation of oil‐like stains. Water is required to destabilize silicone sealant and to drive the migration of the degradation products through the porous media and towards the surface of the plate exposed to rainfall.

The real challenge of Alaska's changing telecommunications landscape is approaching the opportunities in an orderly and logical manner. Given the exciting nature of the possibilities that new technology presents, it is all too easy to get wrapped up in what is new, instead of what is truly useful. For that reason, the main focus of the Telecommunications Information Council (TIC) in the near future will be developing and adopting a comprehensive technology plan for the state, and then examining where new technologies fit into that plan. The Knowles/Ulmer administration's first task in this effort was to reinvigorate the TIC and charge it with taking the lead in bringing Alaska back to the forefront of telecommunications technology. Our state has long had a reputation for leading the way in telecommunications. Our climate, geographic size, and location have always forced Alaskans to be innovators in technology. Supercomputers and satellites have operated in and above our state for many years, but much of that momentum was waning. That needed to change.