Advanced Engineering Forum Vol. 34

Abstract: In this paper, we propose to use a spectrometer (SCIO) manipulated by a robotic arm to determine the carbohydrates content in fruits and vegetables. The vegetable products are moved on a conveyor belt according to the robotic process. In order to increase the economic efficiency, the robotic system can be placed in a detachable module that can be easily transported in various places for spectrometric analysis. After the analysis, the robotic system will place on the fruit / vegetable packaging a label containing information regarding the carbohydrates concentration in fruits / vegetables.

Abstract: The basic concepts of Kuntscher's centromedular osteosynthesis remain largely valid today: centromedular osteosynthesis must be conducted under fluoroscopic control and without fracture outbreak exposure to avoid contamination, the rod must be strong enough to withstand stress caused by muscle contraction, joint movement and body weight load, this to avoid twisting and tearing the rod, the rod must exhibit sufficient elasticity to compress during insertion into the canal and then re-expand for firmly fix the fracture fragments and prevent their rotation. On the other hand, osteosynthesis with flexible centromedullary rods is mainly used in pediatric surgery where elastic rods in secant arch are used applying the principles of stable elastic osteosynthesis. Starting from the research done worldwide, we examined the orthopedic implants used in the long bones as a whole and some inconsistencies were found between the osteosynthesis material and the bone tissue. The necessary materials used in the study are orthopedic implants, different in structure, elasticity, dimensions, which were tested on bone virtual models, according to the CT scan sections. With the help of normal bone virtual models, both bone strength, various orthopedic implants, and the resistance of the osteosynthesis material used were taken into account. On these complete virtual models various simulations were made using FEM. The potential for FEM use in orthopedics and biomechanics has often been overestimated. In many situations, inappropriate use of the method on complicated biological structures can become costly, inefficient or prone to errors. Also, nonlinear soft tissue material has created new difficulties. But these disadvantages and limitations have been diminished successively through new results of biomechanical researches, but also by improving the method by using new types of finite elements. From this results database obtained through various virtual experiments, account will be taken of the most common accidents and incidents occurring in the implanted bone, and solutions will be sought to improve post-implant bone quality.

Abstract: Prosthetic alignment is one of the most important factors, both in terms of the correct functioning of neoarticulation and the survival duration of knee arthroplasty. Significant changes in the alignment of prosthetic components affect the distribution of stress in the knee joint. These changes may also affect the distribution of stresses on the contact surface, soft knee joints, and the subjacent bone remodeling under these forces. The malposition of the components and, in particular, the tibial component in the varus, which in practice is the most common situation alongside the malrotation of the femoral component, leads to the excessive intimal tension of the internal tibial plate by the summing of the additional stresses at this level with its physiological loading from during the unipodal support phase during the walk. Although valuable, all of these studies have no capacity to assess these changes in the kinetics of in vivo knee arthroplasty. Two methods are used for this: telemetry and mathematical models. Traditionally, telemetry has been used to determine the forces acting on the hip, and more recently, on the knee. It values ​​very precisely the value of the axial rotation forces as well as the moments of bending; however, this method is little used, because the necessary equipment is very expensive. Taking this into account, the most used method is the finite element method. The objective of this study was to investigate the effect of malpositioning in the valgus and varus of the tibial component on tension developed in polyethylene as well as in the subjacent bone. Obviously, other situations have also been analyzed. In this direction a series of original numerical models of the anatomical elements (tibia, fibula, femur) of the knee were constructed to simulate the biomechanical phenomena occurring in the normal and prosthetic joint during physical activities, in order to evaluate the factors that influence the duration operation of total knee prostheses.

Abstract: Treatment of hip pathology has evolved over the last two centuries, ranging from rudimentary surgical procedures to modern hip arthroplasty, with an explosion marked in the last 30 years, considered to be one of the most successful surgeries to date. Hip arthroplasty is a permanent challenge due to the desire to discover the "supreme prosthesis", for which competition is still open. Hip disorders requiring prosthesis show a change in articular morphology. Among the most common medical conditions that have as final therapeutic solution hip arthroplasty are: coxarthrosis, both primary and secondary, followed by traumatic conditions: femoral neck collapse and femoral neck pseudarthrosis, aseptic head necrosis femoral stage III, as well as rheumatic coxitis from rheumatoid arthritis, ankylosing spondylitis or juvenile art. Endoprosthetic arthroplasty can be defined as an intervention of reconstructive surgery with bone sacrifice and prosthetic replacement of the articular components. It is, in the end, an operation aimed at restoring joint mobility and normal functioning of the muscles, ligaments and other periarticular structures that control joint movement. The materials initially used (glass, metal, plastic) did not have the desired bone strength and integration capacity. It followed the development of cemented implants, obtaining different types of cement with better and better quality. Problems arising from cemented arthroplasty (decimation, involving prosthetic revision) have led to a parallel development of the design and materials used for uncured prostheses with the possibility of very good integration of prosthetic material into the bone, raising them to the top of preferences in recent years. Treatment of hip pathology has evolved over the last two centuries, ranging from rudimentary surgical procedures to modern hip arthroplasty, with an explosion marked in the last 30 years, considered to be one of the most successful surgeries to date. The purpose of this study was to obtain the three-dimensional models of the hip joint and the prosthesis for the use of these models for various analyzes and virtual experiments. At the end of the paper important conclusions were drawn based on the results obtained in the simulations using the finite element method.

Abstract: The human skull and the maxillary bones have a very complicated architecture, determined by the outer walls, by the internal bone structures and their joining. In this paper CAD parametric software has been used to define complex virtual models. First, the mandible and jaw were defined using CT images. These images were imported into a CAD software using specific techniques and methods. These models have been finalized in SolidWorks where the virtual model of the studied system has been generated. Then, the virtual models were exported to a software for FEA simulation and prepared for every dentistry simulations. The structure of the maxillary bones contains spongy bone tissue, cortical bone tissue along with dental tissues. Each of these tissues have certain properties (elasticity, plasticity, density) assessed by flexibility. The analysis of the mechanical tension of the dental structures has been a subject of interest in recent years in order to determine the state of tension in the dental structures and to improve the mechanical strength of these structures. Such numerical techniques can give a better understanding of reactions and interactions of individual tissues. This involves a series of computational procedures to calculate stress in each element. Field variables can be interpolated by using form functions for scientific verification and validation of clinical assumptions. Various loadings have been applied to a personalized skull obtained from CT images using CAD techniques and procedures. On this system, FEM simulations were made and maps of stress, displacements and deformations were obtained that show the mechanical behavior of the maxillary dental system. Finally, important conclusions were highlighted.

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: Conform municipal solid waste (MSW) landfills will continue to be used, in the nearest future, in accordance with environmental protection legislation. Due to this fact, the environmental factors such as: water, air, fauna and vegetation, soil, as well as the human health will be affected. The Greenhouse Gases (GHG) emissions (CH₄, CO₂, N₂O, other nitrogen oxides, water vapor steams) are taken into consideration being responsible for a great part of the world environmental changes, 3÷5%, approximately. It is to be noted that, on the national territories, the GHG emissions should be considered due to a bad management of those. The MSW landfilling allows collecting landfill gas (LFG) in a place by collection and treatment of CH₄, CO₂ and H₂S, for economical purposes and human beings health protection. Methane (CH₄) is a strong GHG but has economical value and in the same time, is an important energetic source. Collecting this gas involves important costs. Waste disposal have to be analyzed from the point of view of its enclosed constituents, humidity kept, permeability, biodegradation rate, compacting density, temperature inside the landfill body and atmospheric pressure variations. This article is dedicated to studying the parameters of LFG collection wells, which are used as part of vertical collection systems. For this purpose, the modeling approaches to the main processes occurring in the porous medium of the landfill (MSW) are taken into account.

Abstract: Water is an irreplaceable resource for humanity. On average, 65% of the weight of the human body is water, but it is present in the structure of the whole flora and fauna of the planet. Moreover, for many plants and animals, water is their living environment. Extensive use of water in industrial processes, inadequate waste water treatment, exponential demographic growth have made water from a resource available to everyone in a depleted resource. Sustainable development is a component of integrated water resource management.

Abstract: Achieving Europe's sustainable development goals by 2030 is conditioned by the transition to the circular economy. Turning waste into resources is one of the key phases in driving this process. The paper presents the sectors in Mehedinţi County that are involved or have proposed long-term objectives in the field of waste.

Abstract: Romania was the first Eastern European country to be has joined the Partnership for Renewable Energy and Energy Efficiency. The potential of Romania in the field of green energy production is as follows: 65% biomass, 17% wind energy, 12% solar energy, 4% micro hydro power plants, 1% + 1% photovoltaic + geothermal. Maximizing the full potential on the various green energy categories require serious investment and requires facilities granted to investors in this sector. Renewable energy sources can effectively contribute to increasing internal resources, which gives them a certain priority in energy policy.