Papers by Keyword: Shape

Abstract: There are a lot of dental implants kit designs [1, 2, 3]. All of them are based on a pin or a screw either cemented or osseointegrated into the human jaw. This paper makes a study on the shape the pin or screw dental implant should have. Presented theoretical research was performed using DEFORM 2DTM software simulations, [4]. There were studied several shapes of the dental implant, both for pins and screws. The studied shapes were, basically: cylindrical, conical, ogival and pointed. The criterion for analysis was the effective stress into the jaw bone during the insertion. As a conclusion, the optimal shape of the dental implant depends on the real case, being a customized shape depending on the current conditions of insertion.

Abstract: The article discusses the features of the casting process of non-ferrous metals, the basic properties of various alloys, affecting the appearance of various defects of the resulting casting. The proposals to improve the efficiency of the casting of non-ferrous metals in metal molds and specific recommendations for improving the performance properties of metal depending on the melt being poured are given.

Abstract: In the article there will be a consideration of collapse process progressive simulation of a high-rise building by removing the first-floor columns. The object of the study will be a 27-storeyed high-rise building. The high-rise building structural concept will consist on a monolithic reinforced concrete frame. The mounting base structural concept has been modeled as absolutely rigid. Static and dynamic calculations have been performed in the «Ing +» software complex, while the wind load pulsating component was taking into account using the finite-element method for the spatial slab-and-rod model. The dynamic calculation analysis has shown the obtained oscillation forms corresponding to the design requirements. The stress-strain behavior has been studied for the floor slabs as reinforce constructive of a typical floor. Structural concepts for the building frame of a high-rise building have been developed to reduce the progressive collapse risk. In the physically non-linear calculations, with the removal of the first-floor corner and central columns, four options for the sandwich floor slabs reinforcing were taking into account. The rational reinforcement option has been selected, in which the building is resistant to progressive collapse. The building frame structural concept with the floor slabs heavy-duty reinforcement of the first five floors has been suggested. An outrigger floor with encircling reinforced concrete trusses along the outer contour was included to reinforce the load-carrying framework. Recommendations on the choice of rational structural concepts, reducing a high-rise building progressive collapse risk have been given.

Abstract: The SiC ceramic membrane supports by using four different processes were prepared by extrusion molding process. Shape and distribution of pores in SiC ceramic membrane supports were observed by SEM, Meanwhile the O-ring strength was measured. By analyzing the relationship between pores’ shape, distribution and O-rings strength, the optimal data of apparent porosity and the optimal pores’ shape and distribution was obtained. By means ofusing similar particle sizes, particles modification, controlling drying rate of the green body and controlling the contents of glass phase in neck part between SiC particles formed at the high temperature, the SiC ceramic membrane supports with the O-ring strength greater than 20 MPa were prepared.

Abstract: In a manufacturing process it may be necessary to distinguish the parts of various types produced by different machine-tools and placed on a conveyor. Using an artificial vision system represents a possible solution. Images of the parts can be periodically taken using a video camera. It is considered that all parts are positioned with one of the faces which defines its type on the upper side. Thus, parts’ recognition can be solved by recognizing the shapes from the images. In addition, information about position and orientation of parts can be determined using the captured images. All these information are listed in a text file which can be used by a decision algorithm. This algorithm can choose which parts are useful to assemble different objects. An industrial robot can be commanded using a program written in RobotStudio environment’s programming language (RAPID) to pick the needed parts and place them in a storage area.This paper describes a recognition and measurement of position and orientation method of the different parts produced. In addition, details about implementing this method in MATLAB environment using Image Processing Toolbox and geometrical relations are provided gradually.

Abstract: High volume fraction diamond/copper composites with different diamond shape were prepared by vacuum pressure infiltration. In this paper, the effect of diamond type on thermo-physical properties of the composites was researched. The results showed that the composites with broken diamond exhibited the lowest thermal conductivity and coefficient of thermal expansion, only 401W/m•k and 6.2×10^-6m/K respectively, and the composites with monocrystalline diamond had the best properties, reaching to 527W/m•K and 8.3×10^-6m/K respectively, and the properties of the composites with modified-shape diamond were in the middle. The difference in the properties of the composites with different-shape diamond is attributed to their various specific surface areas.

Abstract: The color, shape and texture are the basic intrinsic features of visual scene and important features for scene recognition and visual salient feature. The recognition of four targets of “bird”, “ball”, “butterfly” and “flower” under the color image, gray image, edge image and low-pass blurred image was completed in the paper through psychology experiment, and the experimental result showed that the speed to recognize the color image was quickest, it was a little slower to recognize the gray image with the same accuracy of the color image, the edge image had a great impact on the recognition of certain object, thus increasing the recognition time, the blurred image increased the time to recognize various objects while reduced the recognition accuracy. The cognitive research on the scene image’s visual feature is helpful to reveal the secrets of human information processing and explore the law for the formulation of human visual saliency.

Abstract: This paper is aimed at a comparison of different types of steel fibres in relation to their influence on the final mechanical properties of High Strength Concrete (HSC). The most affected characteristics of concrete were fracture energy, flexural and split strength, which are the main goal of using fibre reinforcement, as HSC has otherwise low ductility, that can result in sudden failure of a concrete structural element. Expected better behaviour of high-strength steel fibres hooked at the ends than of the ones of normal strength with only flattened ends was approved. The highest values of fracture energy was achieved with the longest steel fibres – 60 mm (diameter 0.75 mm). Whereas shorter fibres (30 mm) of the same diameter reached increased flexural and split strength.

Abstract: The moving of a population of agents in a closed rectangular cell is emulated by adding the bouncing of the agents at boundaries and the remembering of end boundaries to a basic model, in which only the alignment rule is used. The agents herd in only a few clusters, which move asymmetrically along the long side of the cell. The effects of the end-boundary information holding time , noise strength and number of agents on the formation and turning of the cluster are investigated. The results show that, the formation time of the cluster decreases with , but increases with and ; the turning time of the cluster slightly increases with and , but nearly does not change with .

Abstract: Conducting hydraulic piston engine design constraints on the design of the crankshaft counterweight mostly by trial calculation algorithm to calculate than the larger. In this paper, three-dimensional parametric mapping software use Dassault Systemes (SA), a subsidiary of SolidWorks under strong secondary development technology, combined with engine design now used widely in the counterweight model to explore the principles of optimal design of the crankshaft counterweight their method, derived crank weight optimized design model.