SETTING THE DRILLING – BLASTING PARAMETERS DEPENDING ON THE GEOMECHANICS OF ROCKS |
Author : ARAD VICTOR, ILIAS NICOLAE, ACHIM MOISE, ARAD SUSANA |
Abstract | Full Text |
Abstract : In order to improve the performance of mine workings development technologies is necessary to establish optimum process parameters for drilling - blasting operations, as a function of the geo-mechanical characteristics of rocks. The most important condition for successful drilling - blasting operations, with respect to the technical, economic and safety point of view, is a realistic projection of their choice, both in terms of explosive materials and concerning the operating parameters. The most important characteristics of rocks which give guidance on the excavation by drilling - blasting are: compressive strength and abrasiveness of rocks. The paper deals with the speed of drilling and explosive specific consumption for the two strength characteristics of rocks. |
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STRESS MANAGEMENT AND WORK PERFORMANCE – A CASE STUDY |
Author : BAZGAN MAGDALENA-CAMELIA, BAZGAN MARIUS |
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Abstract :Currently, more and more organizations begin to understand and be increasingly concerned to obtain benefits from implementation of coherent human resource management, as a result of a modern management and professional focused especially on employees in order to maximize the performance during their remaining within the organization. Work is now no longer just a way of satisfying individual necessity but also as an opportunity that contribute to shaping a favorable self-image. This article aims to capture the relationship between stress management and work performance. |
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OPTIMISATION DESIGN OF WORKING TOOLS SHAPE FOR A CONCRET MIXING EQUIPMENT WITH PALETTES |
Author : DEBELEAC CARMEN |
Abstract | Full Text |
Abstract :The article presents the evaluation of two design variants of mixer tool. The new obtained solution was the result of an optimisation process of geometrical parameters, such as: dimension, thickness, mass and shape. The initial parameters were acquired from concrete mixer in operation in Romania. The objective was to decrease the overall mass of mixer tools while improving its structural integrity. In addition, the new shape of equipment arms increases the process quality for the blending of mixture components. |
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VARIATION OF STRESS CREATED BY WAVES AND MARINE CURRENTS IN A LEG OF OFFSHORE PLATFORM |
Author : DOBROT OANA-MIRELA, MOCANU COSTEL IULIAN |
Abstract | Full Text |
Abstract :The offshore platform have usually leg for sustaining on sea deep. The calculus of the legs is very complicated because of the variation of the loads in time. In this paper is present the numerical results for charging of a leg with forces caused by waves and marine currents. The software for calculation of force induced by water use Airy theory (for regular waves). The structure has been analyzed numerically using the program Solid Works-COSMOS/M (stress and displacements), and FORHID (loads). |
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THE VARIATION OF THE VICKERS MICRO-HARDNESS IN THE VICINITY OF THE FRACTURE SURFACES AT STATIC LOADING |
Author : GOANTA VIOREL, AXINTE TOADER, IFTIMIE DUMITRU GEORGE |
Abstract | Full Text |
Abstract :The paper presents an experimental and analytical process aimed at establishing correlations between the hardness value and the level of plastic deformation. In these conditions, static tensile tests were performed on the compact specimen. These tests allowed us to determine the KIc fracture toughness, as well as to obtain surfaces generated by the material fracture. In the vicinity of the fracture surfaces, Vickers micro-hardness tests were also performed. Two types of determinations were utilized for normal OLC45 steel and for the annealed OLC45 steel. Significant differences regarding the Vickers values were observed; they were determined by the differences which appeared around the crack. |
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THEORETICAL ASPECTS REGARDING THE ANNULAR PLATE LOADING, SIMPLE LEANED ON THE BOTH EDGES, UNDER THE ACTION OF AN UNIFORM DISTRIBUTED PRESSURE ON A FACE |
Author : IATAN I. RADU, POPA T. CARMEN, MENGHER RUXANDRA |
Abstract | Full Text |
Abstract :The paper, taking in discussing the loading of the annular plates given of a uniformly distributed pressure on one side, with simple leaning on the outlines, compares two versions of analysis. The appropriate expressions of the vertical displacement of the plate and of the radial and annular stresses for each study case are shown. |
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AN ANALYTICAL MODEL FOR STRENGTH CALCULUSOF HIPERSTATIC STRUCTURES |
Author : MIRIŢOIU COSMIN, ILINCIOIU DAN, JIMENEZ JUAN PABLO, ROŞU CĂTĂLIN |
Abstract | Full Text |
Abstract :In this paper, it is presented an analytical model based on the “forced method” and Mohr-Maxwell theorem, for strength calculus of three dimensional hiperstatic structures under static loadings. The calculus results are parametric for generalizing the solution. In the end, the theoretical aspects are used for a particular case. |
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UPON THE INFLUENCE OF SOME PARAMETERS, IN NUMERICAL ANALYSIS BY SPH |
Author : NĂSTĂSESCU VASILE, ILIESCU NICOLAE |
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Abstract :In some cases SPH method is more suitable than Finite Element Method (FEM) and this is more and more used also in applied mechanics. In structure numerical analysis some parameters essentially influence the results, among these the constants of the material models and some specific parameters of the method have a maximum importance. It is about the most used material models like plastic-kinematic material model, isotropic-elastic-failure material model, Johnson-Cook material model and others, which take into account the strain rate. This paper comes with some results of our experience in using of the material models together with SPH (Smoothed Particle Hydrodynamics) method. The influence of the smoothing length, distance between particles, the number of these are also numerical investigated. Our established conclusions, supported by graphics and quantitative appreciations could be useful for the researchers working in numerical analysis field. |
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ORTHOSIS “COMARNA” – FORCES ACTING ON THE JOINT ORTHOSIS |
Author : RANCEA ADY |
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Abstract :If the Achilles tendon stalks, the emergency surgery involves the ligation and the recovering of the tendon of interest. The interest in physical therapy is for a model that would allow adjustment dorsifled stages, the number of degrees, and the final stage the same orthosis to submit a joint motion for free care. The Comarna orthosis solution is for these stages, a cut in the leg support in making a dynamic orthosis to assist. The paper addresses the leg in terms of biomechanical and choosing the right type of mechanism. |
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MECHANICAL AND ELECTRICAL PROPERTIES OF TERNARY Cu–In–Sb SYSTEM AT 400C |
Author : DESIMIR PETKOVIĆ, AJKA ALJILJI, MILAN KOLAREVIĆ, DUŠKO MINIĆ, DRAGAN MANASIJEVIĆ, DRAGANA ŽIVKOVIĆ |
Abstract | Full Text |
Abstract :For the complete definition of the properties of the ternary Bi–Cu–In system, there were performed the investigation of micro structures, hardness by Brinel, and electric conductivity of the alloys. In the range of this ternary system, numerous alloys were tested for three vertical sections, with molar ratio Sb: Cu= 1, Cu:In= 1, Sb:In=.1. By application of CALPHAD method, and software package PANDAT 8.1, there were calculated the isothermal cross section at 250C and 400C. |
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DETERMINATION OF THE MAXIMUM FORMING ANGLE OF SOME CARBON STEEL METAL SHEETS |
Author : RADU CRINA |
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Abstract :The maximum forming angle is the most used criterion to express the material formability limit in the case of single point incremental forming (SPIF) process. By knowing this angle, it is possible to asses if a particular part could be obtained by SPIFing a certain material with a certain thickness. In this paper two geometries of part and three thicknesses of metal sheet were tested, in order to determine the maximum forming angle. The chosen material was the DC01 carbon steel, due to its good malleability and ductility properties and large industrial applicability. |
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DEVELOPMENT AND STAGES OF INVESTMENT PLANNING AND ASSIGNEMENT OF CONSTRUCTION IN INVESTMENT BUILDING |
Author : ŠERIFI VEIS, DAŠIĆ PREDRAG, ĆURČIĆ SREĆKO |
Abstract | Full Text |
Abstract :Process protocol of the implementation of investment building project is characterized by a process access to business, which requires a prior defining of the general process structure of investment building. It can be defined as a manner in which the processes are regulated, which is involved in designing and execution of construction works, in order to achieve efficient, effective and cost-effective design and construction. |
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IMPACT OF BACILLUS MEGATERIUM ON FERTILIZATION WITH PHOSPHOGYPSUM |
Author : ŞTEFĂNESCU IOANA ADRIANA |
Abstract | Full Text |
Abstract :In this work rhizosphere bacteria’s study present the capacity to increase plant tolerance of grown environment under conditions of added phosphogypsum (PG) (sub-product of phosphoric acid industry). The results obtains were demonstrated that the effects of Bacillus megaterium on the formation of the plant–rhizobium symbiosis of soybean plants depended in the majority of cases on both of the bacterial suspensions presence and PG quantitative ratios. The study shows that the bacterial strains of Bacillus megaterium facilitated an increase of germinated soybean plants. Also the weight and the height increase for all different soils amended with PG. |
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FRACTURE MECHANICS TESTING OF HIGH DENSITY POLYETHYLENE (HDPE) PIPE MATERIAL WITH COMPACT TENSION (CT) SPECIMENS |
Author : ULMANU VLAD, DRĂGHICI GHEORGHE, ALUCHI VIRGIL |
Abstract | Full Text |
Abstract :The lifetime of polyethylene pipes used for water and natural gas distribution is usually estimated based on relatively long-time creep tests. The pipes fail in service at room temperature and low stress in brittle mode called "long-time brittle failure". In order to economically predict the long term creep performance of HDPE pipes, short term static or fatigue tests are used, in which the crack growth rate is substantially increased. One of the recent tests capable of presenting results useful for HDPE pipe failure prediction is based on the concepts of fracture mechanics. The paper the tests performed on CT specimens cut directly from the HDPE gas pipe in order to determine the fracture toughness the crack propagation rate in fatigue and the crack propagation rate at different loading speeds. The crack propagation speed was monitored by video-controlled technique. |
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IMPORTANCE OF STORAGE SYSTEMS IN DEVELOPING MICRO-GRIDS AND SMART TECHNOLOGIES |
Author : RADUCAN ELENA, MORARU LUMINITA, GURGUIATU GELU |
Abstract | Full Text |
Abstract : Storage technologies have a huge financial impact on the clean energy sector by reducing financial losses due to outages and poor power quality. They can improve the return the investments in renewable energy structure and reduce end-user electricity costs. Because of their abilities, storage devices represent an important component of micro-grids; this structure being, basically, a weak electrical grid which can be easily subjects to disturbances. Also, the micro-grids can become the incubators of smart grid technologies, because they comprise almost all of the components of a larger grid. This paper is an overview of storage systems, and a review of micro-grids and the latest smart technologies. |
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