Liviu Lazar
University of Oradea
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Featured researches published by Liviu Lazar.
ASME 2016 International Mechanical Engineering Congress and Exposition | 2016
Petru A. Pop; Liviu Lazar; Florin M. Marcu
The mechanical vibrations’ therapy is widely used as a non-conservative and safe physical method for patients diagnosed with osteoporosis, postmenopausal women and sportsmen training, also during athletes’ recovery and rehabilitation phase.This paper has the main goal in assessing the benefic effects of whole-body-vibration (WBV) therapy applied to professional sportsmen as a complementary alternative of training that can improve their sport performance and quality life. The experiment applied on a group of ten volunteers’ athletes from our university, with the ages between of 19 to 29 years and appropriate weight and height, which signed a statement on by self-agreement to participate in this study. The WBV trial performed via a proper dynamic vibration installation during of two months, where the subjects were sitting in a bed with upper limbs on their thighs and inferior limbs extended to provide support for the spine in a fixed support. The installation comprised a vibration bed with direct control of vibration signal and an electronic analyzing system for acquisition and interpretation of vibration data, which allowing an automat control of rotation frequency, alarm and safety system, and visualization on-line the measurement process. The electric motor of vibrating bed can generate predictable vibration values on three axes that used two types of tri-axial vibration sensors, one accelerometer fixed on bed and the second that is an implant accelerometer on the anterior face of the thigh of evaluated subject. Each mechanical vibration training session has performed with a frequency of 45 Hz during of 16 minutes, consisted in eight series with 60 seconds, and one-minute breaks in between. The evaluation of data has made by assessing the values of subjects recorded at the initial stage and at final therapy, which supposed to control the objective parameters, as standing long jump, standing high jump and intensity of exercise performed during of physical efforts.The results of vibration trial stressed that the subjects had a significant increase of sport performances after vibration training at each parameter assessing, which means that WBV can be a viable alternative method used of sportsmen to improve their athletic performance and quality life.Copyright
ASME 2013 International Mechanical Engineering Congress and Exposition | 2013
Petru A. Pop; Liviu Lazar; Florin M. Marcu
Osteoporosis is a systemic skeleton disease, characterized by a low bone mass and micro-architectural deterioration of bone tissue with consecutive increasing of fragile bones and susceptibility of fractures. Risk facture, advanced ages, family history, rheumatoid arthritis, low calcium intake, physical inactivity, and low body weight can lead to this condition. The aim of treatment in osteoporosis is to grow-up the bone mineral density of the skeleton and to increase resorption of formed bone, used diverse methods as medications, conservative measures, weight reduction, physical and occupational therapy, mechanical support devices and surgery. This paper presents a balneal-conservative treatment applied to 82 patients diagnosed with osteoporosis from Rehabilitation Clinical Hospital of Felix Spa in 2011–2012, which has combined with a kinetotherapy and medication treatment. The complex rehabilitation treatment involves balneal-physical-kinetic recovery treatment that must be periodical repeated every six months, while the subjects themselves at home followed the kinetotherapy with drugs between balneal-treatments at hospital. The significance of rehabilitation treatment for the osteoporosis patients is to rise both functional and independence level, and improving their quality life. DEXA, Qualeffo-41 Test, fragility fractures, difference of height patients, using the statistical analysis have performed the evaluation of trial. These results emphasized the efficiency of balneal-rehabilitation treatment with main accent on respect the kinetotherapy applied the osteoporosis patients. The future research will be focused upon the implementation of vibration therapy with balneal-conservative treatment on patients with osteoporosis to reduce the therapy time and improving the quality patients life.Copyright
ASME 2012 International Mechanical Engineering Congress and Exposition | 2012
Petru A. Pop; Liviu Lazar; Florin M. Marcu
Osteoporosis (OP) represents the most common metabolic bone disease, characterized by the shrinkage in bone mass and the destruction of bone quality, thus conferring a higher risk for micro-fractures and injuries. The goal of treatment in OP is to grow-up the bone mineral density of the skeleton and to increase resorption of formed bone, due to improving the quality life of patients. The methods are diverse, such as medications, conservative measures, weight reduction, physical and occupational therapy, mechanical support devices and surgery. This paper presents a balneal-conservative treatment of patients diagnosed with OP from Rehabilitation Clinical Hospital of Felix Spa. The treatment is complex and involves balneal-physical-kinetic therapy or balneal-physical-kinetic recovery treatment, which must be periodical repeated every six months to obtain good results. The study has been applied to two separate groups of patients with OP between 2009–2011. The first group of 100 subjects, presented clinical symptomatology, as pain of variable types like backaches, fragility fractures or deformation of bone shape that resulted from fractures or alterations of weakens bones. A second group of 80 subjects, received the balneal-rehabilitation treatment combined, or not with physical exercises. DEXA and SF-36 scores, using statistical analysis, performed the evaluation of OP treatment. The results of experiment emphasized the efficiency of balneal-rehabilitation treatment applied patients with OP. The future research will be focused upon the implementation of vibration therapy with balneal-conservative treatment on patients with osteoporosis and osteoarthritis to reduce the therapy time and improving the quality life of patients.Copyright
ASME 2012 International Mechanical Engineering Congress and Exposition | 2012
Petru A. Pop; Patricia A. Ungur; Liviu Lazar; Mircea Gordan; Florin M. Marcu
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
Volume 8: Mechanics of Solids, Structures and Fluids; Vibration, Acoustics and Wave Propagation | 2011
Petru A. Pop; Patricia A. Ungur; Liviu Lazar; Florin M. Marcu
Solving the acoustical problem and improving the impact indoor environmental quality represents a priority for many researchers and manufacturers of materials with a high noise reduction of coefficient rating. The paper presents a real solution for determination the sound-absorption coefficient of materials with acoustical properties from the gypsum family. The procedure used for test is standing wave method into a Kundt tube. The experiment setup used a complex installation of a Kundt tube containing a loudspeaker for emitting the sound waves at a well-defined frequency by a first PC, a microphone for detecting and transmitting the signal to a second PC for analyzing and processing the data. All of these were performed by using MATLAB Programs. Tests were conducted with two material samples with original receipts, one from gypsum and other from special gypsum plaster with sound-absorbent properties. The frequency was set separately for each material from 50 Hz to 1250 Hz to determine their sound-absorption coefficients. The result of experiments shows the efficiency of installation and superiority of special gypsum plaster vs. gypsum along entire frequency range of testing that can be carrying on to other materials with sound properties.Copyright
Volume 2: Biomedical and Biotechnology Engineering; Nanoengineering for Medicine and Biology | 2011
Petru A. Pop; Liviu Lazar; Florin M. Marcu
The analysis and implementation of modern treatments for the patients diagnosed with osteoporosis, degenerative rheumatic affections and peripheral circulatory disorders have become a healthy priority for the society. These treatments have the goal to raise the bone mineral density of the skeleton, reducing joints pain and inflammation while improving and maintaining joints function. This paper presents a conservative treatment of patients from Recovery Clinical Hospital of Felix Spa, diagnosed with degenerative and rheumatoid affections. The treatment is complex and involves balneal-physical-kinetic recovery therapy that must be periodical repeated at every six months to perform. Ankylosing spondylitis was been evaluated by BASFI-BASDAI scores, while the gonarthrosis with Artroflex by SF-36 of quality life scale and Lequesne index. In addition, a vibration treatment combined with balneal-conservative treatment was been proposed to reduce the therapy time and improved the quality live of patients. The vibration system comprises a vibration bed with adjusting control of signal by a digital frequency convertor, and a command panel system for measuring and processing of data. Because the vibration trial is in incipient experiment stage, it was been applied first on Wistar rats, due to increase the calcium mass of bones. The results of all treatments were emphasized the efficiency of balneal cure in rheumatic affections.Copyright
ASME 2010 International Mechanical Engineering Congress and Exposition | 2010
Petru A. Pop; Liviu Lazar; Florin M. Marcu
The paper presents some aspects and practical solutions of weight bearing joints treatment for patients with osteoarthritis and following by the rehabilitation process, which has realized at Recovery Clinical Hospital of Felix Spa. A model of human body under applied and conjunction forces explains the damping and shocks into synovial joints from elastic modulus of bone cartilages in contact and variation of dynamic viscosity’s synovial fluid and spine fluid. The conservative treatment of osteoarthritis involves balneal-physical-kinetic therapy or balneal-physical-kinetic recovery treatment, which must be repeated periodical, every six months to get good results. In addition, a vibration treatment of patients with osteoarthritis combines with balneal-conservative treatment is proposed. This vibration treatment system is composed of vibration bed, electrical motor to generate the vibration with direct adjustment of frequency by a digital frequency convertor, and a command panel system of measurement, analysis and interpretation of data from FFT electronic vibration gage. These combination treatments have assured an amelioration of patients with osteoarthritis and improving the bio-lubrication between cartilages of synovial joints, respectively of fluid spine.Copyright
ASME 2010 International Manufacturing Science and Engineering Conference, Volume 1 | 2010
Petru A. Pop; Patricia A. Ungur; Liviu Lazar; Florin M. Marcu
The paper is presented a dynamic installation used for determination the elastic characteristics of gypsum materials, such as elasticity modulus-E, rigidity modulus-G, etc. This dynamic installation is composed from: mechanical device for application of axial force, cylindrical gypsum samples on which are fixed 2 strain gages, 2 bridges circuit type “Switch & Balance Unite SB-10 with digital Strain Indicator-P3500, A/D board and PC. As the samples are used two cylinders with differently gypsum compositions: gypsum of dressing and light orthopedic corsets, and from gypsum with sonic absorbent and thermal isolator properties. The acquisition and the interpretation of data with MATLAB program is realized, by used two original programs: “Daquest-2m” for acquisition data, and “Evaluation-1m” for calculation and plot diagram of shock wave time. By determination of shock propagation time passing through the gypsum sample can be calculated the wave velocity and the elasticity modulus of gypsum tested. For building materials on base of gypsum with special applications in medicine, and panels with sonic absorbent and thermal isolator properties are demand to determine the elastic characteristics to enhance the manufacturing process and usefully.Copyright
THIRD MANUFACTURING ENGINEERING SOCIETY INTERNATIONAL CONFERENCE: MESIC‐09 | 2009
Petru A. Pop; Patricia A. Ungur; Liviu Lazar; Florin M. Marcu
The EU Norms about of protection environment, outside and inside ambient, and human health demands has lead at obtain of new materials on the base of airborne material, with high thermo and phonic‐absorbent properties, porous and lightweight. The α and β‐modeling gypsum plaster quality and lightweight depend on many factors as: fabrication process, granulation, roast temperature, work temperature, environment, additives used, breakage, etc. Also, the objectively appraisal of modeling gypsum quality depends of proper tests methods selection, which are legislated in norms, standards and recommendations. In Romanian Standards SR EN 13279‐1/2005 and SR EN 13279‐2/2005, adaptable from EU Norms EN 13279‐1/2004 and EN 13279‐2/2004, the characteristics gypsum family tests are well specification, as: granule‐metric analysis, determination of water/plaster ratio, setting time, mechanical characteristics, adhesions and water restrain. For plaster with special use (phonic‐absorbent and orthopedic materials, etc.) the...
ASME 2009 International Mechanical Engineering Congress and Exposition | 2009
Petru A. Pop; Petru Ungur; Liviu Lazar; Silviu Corbu; Florin M. Marcu
The paper presents some aspects and practical solutions of synovial joints treatment for the patients with hip and knee osteoarthritis, realized at Recovery Clinical Hospital of Felix Spa, Oncology Clinical Hospital of Oradea and our university. A theoretical model of human body under applied and conjunction forces, explained the vibration damping and shocks into synovial joints from elastic modulus of bone cartilages in contact and variation of dynamic viscosity’s synovial fluid. The treatment was applied to the patients with osteoarthritis that consists in combination between conservative measures with radiological treatment, by using irradiation with gamma ray, due to improving bio-lubrication into cartilages of synovial joints with severe osteoarthritis in slow evolution. The treatment is following by a recovery process of patients such as hydro-kinetotherapy, massage, etc. In addition, a study about 260 subjects with osteoarthritis using balneal-physiotherapy at Recovery Clinical Hospital of Felix Spa is presented. These combination treatments have assured an amelioration of patients with osteoarthritis and due to improving the bio-lubrication between cartilages of synovial joints.Copyright