Mihai Roman

The paper presents a comparison study based on the simulation by the finite element method (using the Ls-Dyna software) on three different incremental sheet metal forming process alternatives for medical implants used for the partial resurfacing of the femoral condylar surface of the knee. The paper also studies the influence of the material thickness and the punch diameters about the stress and strain distribution, the thinning of the material, the force variation and the springback of the material. 1 INTRODUCTION The patellofemoral resurfacing system combines intra-operative, condylar surface, off-the-shelf and contoured articular inlay components. Of these undoubtedly the most important is the condylar surface. This component is obtained in this moment from titanium alloys or Co-Cr-Mo alloys obtained by casting and then coating the undersurface of Cp-Ti as a better quality of condylar surface. There are several different types of surfaces such as the geometrical shape and dimensi...

The autologous osteochondral transplantation is a procedure which transfers osteochondral plugs harvested from a nonweight bearing area of the knee in the area of the chondral defect. The purpose of this study is to analyse the behaviour at compression of a bovine femur from whose trochlea were harvested osteochondral plugs. It has been used a bovine femur with 8 osteochondral plugs harvested from the trochlea. The prepared femur was positioned at the Instron 5587 Machine, then loaded with forces up to 5.000 N, with concomitant aquisition of data with the Aramis 2M System. The acquired data allow the analysis of the principal deformations and tensions at different pressure levels. The values obtained shows that harvesting the osteochondral plugs from the femoral trochlea does not modify the biomechanical behaviour of the femur. Then, It has been realised a transverse section at the trochlear articular surface, allowing the analysis of the behaviour on compression of all points of th...

During history, an aggressive country seeks to force non-aggressive countries to made many concessions based on military force. In our paper we discuss the situation that one aggressive country is dissatisfied with its current position and try to obtain more concessions from a rival country. To analyze this situation we use a game theory dynamic model in complete and incomplete

Time plays a proeminent role in development of a knowledge based society, in a context of changing rhythms of work, ageing of the European population, changing family structures and greater sensitiveness to time issues among European citizens. In this contribution we highlight the manner time is used for economic activities in Romania and situate it in the context of European

Human behavior, rational or irrational one, influences one of the most complex markets worldwide: the insurance market. In most situations, insurance markets are not competitive and risk neutral insurers negotiate under asymmetric information with actors who exhibit risk aversion. In this paper we develop a game theory model that analyzes the negotiation of an insurance contract under risk aversion conditions

Time use survey examines how people allocate their time to different kind of activities. The purpose of the paper is to determine whether significant differences exist between the eight statistical regions observed in Romania. In order to analyze this, we first present the time use patterns in respect with work time, leisure time and with gender. We use the factorial

The debt level in contemporary world is arising dramatically. This paper presents a signaling model that offers a new perspective about government deviation from optimal taxation and delay debt stabilization. The result indicates that we have different types of government (week or tough ) theses will implement a fiscal regime that depends on its reputation. Also, the fiscal regime is

In this paper the authors intend to examine by numerical simulation one of the newest methods for obtaining the knee condylar surface, namely by incremental forming starting from a commercially pure titanium (CP Ti) sheet. In order to study the influence of the geometrical parameters, ...

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The labour market in Romania is facing some imbalances arising from the negative demographic trends, legislative instability, poor correlation between the educational programs with the labour market, low labour productivity. The European Union labour market strategy aims at achieving 75% employment rate by 2020, for Romania the objective being 70% (Europe 2020). Although Romania has enjoyed robust economic growth for the most part of the 2000s, the labour market was experiencing large and increasing shortages of labour and skills, which coexisted with low participation rates, as well as excess supply of labour in declining sectors (mainly agriculture). The negative growth rate of the Romanian population, which has started in the early 1990s has already reduced the population. On top of this, there is the migration of the work force - most of the migrants are still included in the labour market statistics, as inactive, but are absent from the Romania’s labour market and might be part...

This paper is focused on potential GDP and output gap estimation in Romania using a univariate method – HP filter and a multivariate method – production function method that are applied on annual time series covering years 1990-2008. The production function we use is Cobb-...