231 research outputs found

    Correlation between the Quality of Attention and Cognitive Competence with Motor Action in Stroke Patients

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    It is considered that cognitive function and attention could affect walking, motion control, and proper conduct during the walk. To determine whether there is a difference in the quality of attention and cognitive ability in stroke patients and patients without neurological damage of similar age and education and to determine whether the connection of attention and cognition affects motor skills, the sample consisted of 50 stroke patients tested with hemiparesis, involved in the process of rehabilitation, and 50 persons, randomly chosen, without neurological damage. The survey used the following tests: Trail Making (TMT A B) test for assessing the flexibility of attention; Mini-Mental State Examination (MMSE) for cognitive status; Functional Ambulation Category (FAC) test to assess the functional status and parameters of walk: speed, frequency, and length of stride; STEP test for assessing the precision of movement and balance. With stroke patients, relationship between age and performance on the MMSE test was marginally significant. The ratio of performance to TMT A B test and years does not indicate statistical significance, while statistical significance between the MMSE test performance and education exists. In stroke patients, performance on MMSE test is correlated with the frequency and length of stride walk. The quality of cognitive function and attention is associated with motor skills but differs in stroke patients and people without neurological damage of similar age. The significance of this correlation can supplement research in neurorehabilitation, improve the quality of medical rehabilitation, and contribute to efficient recovery of these patients

    Analysis of welding of the rear bridge semi-housing assembly of a firefighter truck by the semi-automatic procedure in gas protection

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    The problem considered in this paper is the welding technology of the steel assembly of a firefighter truck rear bridge semi-housing. Since in this procedure the welding is done of the two dissimilar steels, it is necessary to analyze effects of welding on mechanical properties and microstructure of individual joint's zones. The weldability of the base metal was considered first (semi-housing tube and flange), then the welding method and the filler metal were selected and, finally, the technological parameters of welding were calculated. The computational and experimental methods were used for the base metal weldability estimate, based on the hardness measurements in the joint's critical zones and analysis of their structures. Experimental investigations performed were aimed for verification and/or eventual correction of the proposed welding technology

    Analysis of welding of the rear bridge semi-housing assembly of a firefighter truck by the semi-automatic procedure in gas protection

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    The problem considered in this paper is the welding technology of the steel assembly of a firefighter truck rear bridge semi-housing. Since in this procedure the welding is done of the two dissimilar steels, it is necessary to analyze effects of welding on mechanical properties and microstructure of individual joint's zones. The weldability of the base metal was considered first (semi-housing tube and flange), then the welding method and the filler metal were selected and, finally, the technological parameters of welding were calculated. The computational and experimental methods were used for the base metal weldability estimate, based on the hardness measurements in the joint's critical zones and analysis of their structures. Experimental investigations performed were aimed for verification and/or eventual correction of the proposed welding technology

    Effect of variable load on crack initiation microalloyed steel S 690-QL

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    The accumulation of damage in the form of initiation and growth of micro-cracks is the first stage of destruction that ends when the merger microcracks form macro cracks. Cracks formed in the cycle number N =104 - 105 are the result of low cycle fatigue. From the need to evaluate low cycle fatigue life was carried out to investigate the low cycle fatigue microalloyed high-strength steel S690QL in the heat-treated

    Systematic evaluation of the effects of incubator and media type on pregnancy outcomes following in vitro fertilization

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    Ispitati da li se razlikuju ishodi vantelesne oplodnje zavisno od vrste korišćenog inkubatora, vrste medijuma i njihovih kombinacija u toku postupka vantelesne oplodnje. Ispitati da li se razlikuju telesne mase novorođenčadi zavisno od korišćenog inkubatora, vrste medijuma i njihovih kombinacija u toku postupka vantelesnog oplođenja. Ukoliko se pokaže značajnost razlike u telesnoj masi novorođenčadi i u ishodima vantelesne oplodnje u odnosu na korišćene medijume i inkubatore, ispitati koji medijumi, inkubatori ili koja njihova kombinacija daje najbolji ishod VTO i optimalnu telesnu masu novorođenčadi. Metodologija: u ovu studiju su bile uključene sve pacijentkinje lečene na Odeljenju za arteficijelne reproduktivne tehnologije (ART) Ginekološko-akušerske klinike “Narodni front” u okviru Nacionalnog programa vantelesne oplodnje u vremenskom periodu od devet godina. Studija je obuhvatila ukupno 2617 ciklusa vantelesne oplodnje, od kojih je kod 74 pacijentkinje obustavljena terapija zbog neadekvatnog odgovora na stimulaciju, kod 16 pacijentkina aspiracijom nisu dobijene jajne ćelije, 8 pacijentkina je imalo neupotrebljive jajne ćelije za oplodnju, a 21 muškarac nije dao uzorak sperme. Tako da je analizirano 2498 ciklusa vantelesnog oplođenja. Na osnovu vrste inkubatora i korišćenog medijuma pacijentkinje su podeljene u tri grupe. Prva grupa ispitivanih pacjentkinja u čijoj procedure su korišćeni Cook medijumi i Heracell inkubator (N=1134). Druga grupa ispitivanih pacjentkinja u čijoj proceduri su korišćeni Medicult medijumi i Heracell inkubator (N=697). Treća grupa ispitivanih pacjentkinja u čijoj proceduri su korišćeni Cook medijumi i K-Minc (Cook) inkubatori (N=667). Analizirani su sledeći podaci o pacijentkinjama: godine života, BMI, pušački status, etiologija infertiliteta, broj prethodno uradjenih vantelesnih oplodnji. Analizirani su sledeći podaci vazani za postupak VTO: vrste protokola stimulacije, ukupna količina datih gonadotropina, dužina stimulacije, serumske vrednosti estradiola na dan završne injekcije, broj dobijenih jajnih ćelija, procenat oplodjenih jajnih ćelija, ukupan broj embriona, broj visoko kvalitetnih embriona, broj transferisanih embriona, dan embrio transfera...To assess the effect of incubator and media type and their combinations on outcomes following in vitro fertilisation (IVF) treatment. More specifically, we aim to determine whether newborn birth weight following assisted human conception is affected by different combinations of incubator and media type. Finally, if a significant difference in birthweight and IVF outcomes is revealed depending on incubator and medium used, we aim to determine which incubator/medium combination provides the most optimal IVF outcomes, including newborn birthweight. Methodology: This study initially included all patients treated at the Department of Artificial Reproductive Technologies (ART), Gynecology-Obstetrics Clinic “Narodni Front”, who took part in the National program for artificial conception, within a timeframe of nine years. Primarily, the study included a total of 2617 IVF cycles, while the following cases were excluded: 74 patients who discontinued treatment, due to poor stimulation response, 16 patients who had no oocytes collected following ovarian puncture, 8 patients who had unsuitable oocytes for further fertilization and 21 cases in which a sperm sample was not obtained. Therefore, a total of 2498 IVF cases were analyzed. Based on the type of incubator and medium used, patients were divided in three groups. The first group, consisted of patients for which CooK medium and the HeraCell incubator was used (n=1134). The second group comprised of patients for culture was performed in Medicult medium and the Heracell incubator (n=697). CooK medium in combination with the K-Minc (CooK) incubator was used for the third group of patients (n=667). The following patient data were analyzed: patient age, body mass index (BMI), smoker status, cause of infertility and number of previous IVF cycles. The IVF data analyzed included the following parameters: type of stimulation protocol, total administered dose of gonadotropins, duration of stimulation, total serum concentration of estradiol on the final day of injections, number of oocytes collected, number of oocytes fertilized, total number of embryos, total number of good quality embryos, number of embryos transferred and day of embryo transfer..

    An integral model for management support in family businesses

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    Upravljanje porodičnim kompanijama sastoji se iz upravljačkih, organizacionih, finansijsko-poslovnih, strateških izazova i specifičnih međuljudskih odnosa, koji ne krase nijednu drugu poslovnu organizaciju. Na sve to, kada se uzmu u obzir vrlo kompleksni uslovi današnjeg poslovanja i tržišne prilike, dolazi se do zaključka da vlasnik porodične kompanije razmatra čitav niz parametara pri donošenju strateških odluka. Uspešnost poslovanja porodične kompanije i njen potencijal za rast, može da se adekvatno utvrdi i uz pomoć postojećih metoda i tehnika finansijske analize. Ali, trenutni modeli ne sadrže komponentu pozicioniranja kompanije u pripadajuću fazu životnog ciklusa, jer trenutna literatura ne podržava pretpostavku da se porodične kompanije mogu adekvatno porediti između sebe. Uslovi u kojima posluju porodične i ostale kompanije deluju identično na prvi pogled, ali da se dubljom analizom, poslovanje porodičnih kompanija razlikuje značajno od ostalih kompanija. Kroz izradu istraživanja u okviru disertacije, realizovano je nekoliko zamišljenih ciljeva, a to su: ideja o definisanju integralnog modela za podršku upravljanju u porodičnim kompanijama, zatim mogućnost svrstavanja kompanije u fazu životnog ciklusa i prognoze buduće faze životnog ciklusa, kao i definisanje postavke alata za analizu trenda, koji se oslanja na prethodno navedeno. Model je kreiran uz pomoć metoda i tehnika mašinskog učenja, na osnovu kojih je skup parametara o poslovanju jedne porodične kompanije empirijski proveren na uzorku porodičnih kompanija. Upotreba savremenih metoda i tehnika je kroz softversku obradu doprinela da se definišu sasvim novi parametri, na osnovu kombinacije postojećih parametara poslovanja, a koji doprinose objašnjavanju raznolikosti u pojavi ključnih parametara poslovanja.Family business management consists of managerial, organizational, financial-business, strategic challenges and specific interpersonal relationships which is not similar to any other business organization. Taking into account complex conditions for doing business and market relations, it is concluded that the owner of a family company considers a whole range of parameters, when making strategic decisions. The success of a family business and its potential for growth can be adequately determined with existing methods and techniques of financial analysis. But, current models do not contain a component of positioning the family company into the appropriate life cycle stage, as current literature does not support the assumption where family companies can be adequately compared among themselves. The conditions, where family and other companies operate, are identical at first glance, but following a deeper analysis, business of family companies differ significantly from other companies. Through the development process of the dissertation research, several ideas were realized, namely: the idea of defining an integral model to support management in family companies, then, the possibility of classifying a company in the life cycle phase and forecasting the future phase of the life cycle, as well as defining a tool for trend analysis, which relies on all of the foregoing. The model was created using machine learning methods and techniques, based on which a set of family business parameters was empirically tested, on a sample of family companies. Application of modern methods and techniques through software processing has helped to define completely new parameters, based on a combination of existing business parameters, which contribute to explaining the diversity of measured key business parameters

    Structural integrity assurance of casing pipes in the oil and gas industry

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    The exploitation of casing steel pipes used in oil and gas drilling rigs typically involves a corrosive atmosphere, high pressures and elevated temperatures. These conditions can affect the initiation and development of defects in the material, which can jeopardize t he s afe s ervice o f t he s ystem. I n t his work, a n assessment of the integrity of a damaged pipe, manufactured by high frequency contact welding (HF) of API J55 steel, is presented. The influence of an initial defect (machined surface crack) on the pipe structural integrity is analysed. Besides the defects at the internal surface, which is in contact with the transported fluid, casing pipes are also exposed to damage at the external surface, which is why such configuration is examined here. The analysed surface crack is in an axial direction, bearing in mind that this type of defect is the most severe for the cylindrical pressurised components. Internal pressure testing is conducted on a pipe closed by dished ends. The values of fracture parameters, crack mouth opening displacement CMOD and J integral, were tracked during the experiment. The applied procedure for J integral determination (so-called direct measurement) can be applied both on standard specimens and on structures. It includes the use of combined experimental - computational procedure. Finite element analysis is used for determining the criteria for the pipe failure, regarding both crack growth initiation and plastic collapse of the ligament. The size of the crack is varied in the finite element models, in order to determine the influence of its size on the maximum loading. Simplified 2D models are also examined, with the aim of determining the applicability of such approach. Based on the obtained results, criteria for the integrity assessment of the pipe are discussed

    Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'

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    Presented are results of non-destructive tests performed on the parent material and welded joints of structural parts of a breeches pipe (collar and anchor), and results of destructive tests performed on the parent material of the anchor. Non-destructive testing included visual (VT), mag-netic particle (MT), and ultrasonic testing (UT), while destructive tests included determination of chemical com-position, tensile properties, impact energy and hardness. Based on test results it is established that the major cause for the occurrence of damage in the carrying structure of the breeches pipe no.1 of pipeline III, or in other words, the degradation of anchor parent material and welded joints between the collar and anchor, and between the pipeline and anchor, is in the fact that the breeches pipe started to lean, not on the collar, as specified by design, but on the anchor that could not endure all loads occurring in service

    Experimental examination of fatigue life of welded joint with stress concentration

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    This paper presents results of experimental examinations of stress concentration influence to fatigue life of butt welded joints with K-groove, produced from the most frequently used structural steel S355J2+N. One group of experiments comprised examinations carried out on the K-groove specimens with stress concentrators of edged notch type. Specimens with short cracks (limited length of initial crack), defined on the basis of the experience from fracture mechanics by the three points bending examinations, have been examined according to standard for the determination of S-N curve, and aimed to determine fatigue strengths for different lengths of initial crack and Relationship between fatigue strength and crack length. Other group of experiments comprised examinations of specimens with edge notch, prepared in accordance with ASTM E 399 for three points bending, in order to establish regularity between crack growth and range of exerted stress intensity factor aimed to determine resistance of welded joint to initial crack growth, namely fatigue threshold (ΔKth)

    Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'

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    Presented are results of non-destructive tests performed on the parent material and welded joints of structural parts of a breeches pipe (collar and anchor), and results of destructive tests performed on the parent material of the anchor. Non-destructive testing included visual (VT), mag-netic particle (MT), and ultrasonic testing (UT), while destructive tests included determination of chemical com-position, tensile properties, impact energy and hardness. Based on test results it is established that the major cause for the occurrence of damage in the carrying structure of the breeches pipe no.1 of pipeline III, or in other words, the degradation of anchor parent material and welded joints between the collar and anchor, and between the pipeline and anchor, is in the fact that the breeches pipe started to lean, not on the collar, as specified by design, but on the anchor that could not endure all loads occurring in service
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