Mircea Gordan

A geothermal thermo-electric energy converter for charging lithium-ion battery

The paper analyzes the optimal conditions for thermal power conversion system. Geothermal water source heat and thermo-electrical conversion is performed with cells TEG (thermo electric generators) based on the Seebeck effect. This study developed in the frame of a national research project is useful for ensuring the energy conversion in conjunction with storage Li-Ion battery. Design method uses Matlab-Simulink program and can be generalized for various thermo-electric cells. Batteries inserted into the simulation scheme can be modified by constructive parametric values. Software solution developed can be extended to numerous applications with efficient electronic conversion. Implemented electronic converter has high efficiency as an integrated electronic structure.

A Comparative Study Regarding a Memory Hierarchy with the CDLR SPEC 2000 Simulator

We have built a simulator named, CDLR SPEC 2000. This simulator is based on traces for systems with cache memories. With CDLR SPEC 2000 program we can study, for a memory hierarcy, the next parameters: maping function, block size, writing strategies, replacement algoritm, size of cache memory, number of cache sets (for the set associative caches), number of words form a block. The simulator can be used for the study of cache memory behaviour. Also the CDLR SPEC 2000 program, introduce the calculus of CDLR of a memory hierarchy. A common metric used for the assessment of overall reliability, in a memory hierarchy is the Mean Time To Failure (MTTF), but it doesn’t take into account for the time of data storage in each level. We propose another metric, Cache Data Loss Rate (CDLR), for this reason. We will derive a recurrent formula for computing CDLR, and we will validate it by computer simulation.

Numerical Modeling of Electromagnetic Induction Heating Process Using an Inductor with Constant Step Between Turns

This paper presents a numerical modeling for an induction heating system with axial symmetry. Our induction heating system use cylindrical pieces and one particular property of the inductor is the constant step between the turns of coils. We use a simulation program that will give us a lot of information that are experimentaly inaccesible. To obtain a high precision numerical modeling we use a performant software (Flux2D).

Testing of Sonic-Absorbent Panels’ Behavior in Open-Air Environment

One wildly used method to reduce and control the noise pollution in green city’s buildings is using sonic-absorbent panels. Their applications can be multiple, such as the insulation of buildings, acoustic barriers and fences along the highway or in front of supermarkets, hospitals and other public buildings. This paper presents a method for testing the behavior of sonic-absorbent panels in open-air environment. The work represents a carrying on of previous research about absorbent materials from gypsum family, tested in lab conditions. The experiment setup used a dynamic installation and as a sample a stand formed by six sonic-absorbent panels from special modeling alpha-gypsum plaster. This installation has been composed of two loudspeakers for emitting the sound at a well-defined frequency by the first laptop, the microphone for detecting and transmitting the signal to the second laptop for analyzing and processing the data. All operations were performed using MATLAB Programs, while a Data Logger Sound Level Meter type CENTER 332 was put on near the microphone to compare both results. The first experiment of acoustic stand has been realized by setting up the installation at a frequency from 50 Hz to 1250 Hz and altering the distance between loudspeakers and stand at 0.5m to 1m and 1.5m, respectively. The second experiment kept the same test’s conditions, while two and three layers of sonic-absorbent panels formed the stand, respectively, but at same distance from source of 0.5 m. In both tests, the results underlined the good sonic-absorbent properties of these panels, especially at medium and high frequency, which can recommend using the panels for multiple outside applications.Copyright

The Application of Horizontal Rotational Forming Process in Fabrication of Thermoplastic Sliding Bearings

The paper is presented an application of horizontal rotational-forming in fabrication of thermoplastic sliding bearings for machine tools. In addition, general aspects regarding the flow process of thermoplastics by used rotational-forming of revolution parts are described. The heat of plastic material at melt-temperature point is realized by High Frequency Current Induction (HFCI) on a centrifugal molding installation of bimetallic bushes. From the experiment tests has observed that between melt-temperature point of thermoplastic material, revolution speed and size molding a synchronism is required, which depends of material density and whirl form of melting. The predictable revolution speed of metallic mold has achievement by technological attempts, in function of workpiece size and type of material. The charge weight is experimental determined in dependence of part’s thickness walls. This process leads to obtain the workpieces at high quality level and constant thickness walls. The new bearings have been made from polyamide-PA.6, which changed with success the bronze bearings used at drilling machine tools.© 2010 ASME

Aspects About Sonic Pollution and Vibrations Sources in Urban Area and Solutions for Them Suppressing

This paper presents some aspects about sonic pollution and vibrations sources in urban area, respectively in Oradea town with its metropolitan zone, and suppressing solutions. The noise and vibration pollution in urban area represents an actual theme of environment protection in Europe and other world’s zone. In last time, Oradea Town has known a large urban and economical development, which due to including inside of urban zone two metallic railway bridges “Oradea East” and “Oradea West”, over “Crisul Repede” River. This ambient noise level and vibration loads produced by railway bridges on passing trains must be reduce, increasing of working bridge’s age and population’s comfort. The experiments about of automotive and tram traffic influence of historical monuments and public Oradea’s buildings have been extended, such as church and hospital. The tests have emphasized the necessity of suppressing noise and vibration pollution by mounting of sonic absorbent panels near buildings from railway bridges, phonic insulation of buildings walls, hour’s restriction program of traffic in these areas, and other solutions.Copyright

Rational Using of Small Frontal Rigid Gear Couplings Type Gleason at Simple Direct and Differential Dividing and Geometrical Development of Smaller Size

This paper has presented two constructive solutions of rational using of frontal rigid gear couplings with spherical gear in circle arc type Gleason, knowing as curved frontal gear coupling, on small dimensions, ones for simple direct dividing and second for simple differential dividing, and geometrical development possibility of new family of frontal coupling and small size. The frontal gear coupling type Gleason are formed from two rings, one with concave gear and other with convex gear, being characterized by great twist moments of capacity transmission, realizing a precision angular position, fast central connection and assuring of optimal conditions for manufacturing of mass production and low cost. One new application of small frontal gear couplings was external diameter of O100mm and O120mm, assured a higher accuracy of angular location of ±2″ and a great carrying capacity for couplings by using of compound rest of lathe with ultra precision location. A second application has presented a new landing of simple direct and differential dividing using one or more pair of Gleason’s gear coupling due to construction of new indexing tables with ultra precision in metal cutting.Copyright

Optimal Construction of a Hydraulic Pump With Elliptic Rotated Piston by Kakeya-Besicovitch Application

The paper has presented an application of Kakeya-Besicovitch, third example about commutation of finite element beam endpoints inside of arbitrary small zone. This area is a hypocycloid with three cusped points at that inner tangent has a constant length independent by the point position of its inner tangent, which being rotated in clock-way it’s came back to its original position with its endpoints reversed. The application is a hydraulic pump compound by one rotated piston with elliptical section which is rolling in a fixed chamber with hypocycloid form and three cusped rounded tips after a curvature equal with major axe ellipse endpoints curvatures. The rolling motion is imposed by eccentric exterior source that acting inside of cylindrical pocket located in the center of elliptic piston, which divided the hypocycloid in three equal parts at 120° from each other. The pump could be working as a hydraulic motor which is endowed with rotating distributor that can feed each chamber with variable volume one by one due to moving the piston. The pump’s relevance is given by its efficiency, allowing a large flow capacity to a lower spindle speed, ensured a constant ratio spindle speed which working silence and a large stability.Copyright