387 research outputs found

    DIFFERENCES IN KINEMATIC PARAMETERS OF ATHLETES OF DIFFERENT RUNNING QUALITY

    Get PDF
    The aim of the study was to determine the differences among subjects of different sprinting quality in the variables of running dynamics in the 100 m sprint event and in the variables of kinematic indicators (stride frequency, stride length, foot-ground contact duration, airborne phase duration). The research was conducted on a sample of 133 physical education teacher male students, aged 19 to 24 years (age 21.7 ± 1.08 yrs; body height 180.8 ± 6.98 cm; body mass 76.6 ± 7.62 kg), first year students at the Faculty of Kinesiology, University of Zagreb, who regularly attended their athletics classes. Basic descriptive statistical parameters were computed. Cluster analysis was used to determine sprinting-quality-based homogeneous groups of subjects. The qualitative differences among the subjects pertaining to the defined groups were established by canonical discriminant analysis. One significant discriminant function was obtained differentiating the group of students who performed well from all the other groups of students with poorer sprint performance. The best performance group demonstrated running technique characterised by the shortest foot-ground contact time in the phases of starting acceleration and maximum speed running, and a larger stride length in the phase of maximum speed running

    Nonlocal vs local vortex dynamics in the transversal flux transformer effect

    Get PDF
    In this follow-up to our recent Letter [F. Otto et al., Phys. Rev. Lett. 104, 027005 (2010)], we present a more detailed account of the superconducting transversal flux transformer effect (TFTE) in amorphous (a-)NbGe nanostructures in the regime of strong nonequilibrium in local vortex motion. Emphasis is put on the relation between the TFTE and local vortex dynamics, as the former turns out to be a reliable tool for determining the microscopic mechanisms behind the latter. By this method, a progression from electron heating at low temperatures T to the Larkin-Ovchinnikov effect close to the transition temperature Tc is traced over a range 0.26 < T/Tc < 0.95. This is represented by a number of relevant parameters such as the vortex transport entropy related to the Nernst-like effect at low T, and a nonequilibrium magnetization enhancement close to Tc. At intermediate T, the Larkin-Ovchinnikov effect is at high currents modified by electron heating, which is clearly observed only in the TFTE

    Periodic Orbit Quantization beyond Semiclassics

    Full text link
    A quantum generalization of the semiclassical theory of Gutzwiller is given. The new formulation leads to systematic orbit-by-orbit inclusion of higher \hbar contributions to the spectral determinant. We apply the theory to billiard systems, and compare the periodic orbit quantization including the first \hbar contribution to the exact quantum mechanical results.Comment: revte

    Received formal support in the eyes of the refugees: experiences of refugee parents in exile

    Get PDF
    The humanitarian crises triggered by different events and processes will always create common and different movements and protection needs regardless of the nature of events and reason for its occurrence. Refugee crisis as one of the humanitarian crisis examples has taken a broad place and received attention in society today. The aim of this survey was to research experiences of refugee parents regarding formal support they or their family have received. The qualitative survey was conducted in 2016 in Bulgaria, the host country for many refugees for decades, and a country continually criticised for instances of brutal and inhuman treatment of refugees, as well as for inadequate protection of refugees who have been granted asylum in the country. Research has shown that refugee parents lack support in both ways: receiving psychosocial, financial, material or practical support and in help to enrol their children in school. The participants claimed that one of the biggest challenges they face in Bulgaria is insufficient support from public authorities which caused anxiety, anger and frustration for parents and difficulties in coping with their present life circumstances. Those challenges together with a high sense of responsibility and anxiety over the future prospects of their children represent the key factors of stress for refugee parents. Refugees who lack social support often feel less motivated to engage in activities that would facilitate their integration and they are prone to social isolation, because of which further investigation is needed to understand what is happening with the families who did not receive social support and how to reach them. Whereas social support represents an effective mechanism for coping with the stress and the challenges of displacement, these findings suggest the need for continuous professional support and implementation of psychosocial interventions. Next, the refugee parents expressed their anger and frustration over denied opportunities for inclusion of their children in the educational system. It is thus equally important to conduct further investigation on the resulting outcomes for children who have been excluded from the educational system for longer periods of time. Furthermore, there is need to investigate who supports children once they are involved in the educational system in a host country and what kind of support is provided to them and to their families. This research study has shown many challenges and issues faced by refugee parents in Bulgaria, and emphasises the need for Bulgarian authorities to act responsibly and in accordance with international and national law

    The Croatian Health Survey – SF-36: I. General Quality of Life Assessment

    Get PDF
    The objective of the Croatian Health Survey was the assessment of population health related quality of life in the transitional enviroment of Croatia. Health status measures incorporate dimensions such as physical, psychological, and social functioning, role performance and perception of wellbeing. In order to assess health status, »The medical outcome study 36-item short-form health survey (SF-36) model« was used. A total sample of 5048 inhabitants (1983 males and 3065 females), 18 years and over, represents approximately 1‰ of the general population of Croatia. Mean scores were as follows: physical functioning (PF) 69.94, role-physical (RP)63.01, bodily pain (BP) 64.51, general health (GH) 53.40, vitality (VT) 51.85, social functioning (SF) 72.96, role-emotional (RE) 72.42, mental health (MH) 61.71 and health transition (HT) 44.79. Results of the SF-36 health survey in Croatia are very much like the results in other European countries with indication that general quality of life is lower in Croatia

    Aportes desde la gestión integral del recurso hídrico para la determinación de la capacidad de carga turística en destinos insulares. caso de estudio Islas de Providencia y Santa Catalina

    Get PDF
    Los procesos turísticos que no son adecuadamente planificados generan presión sobre los sistemas ambientales, generando conflictos, problemas y decisiones difíciles de abordar por su complejidad enmarcada en la relación sociedad-naturaleza. Es evidente que estos procesos además de atentar contra el patrimonio natural, representan una gran amenaza para el patrimonio social y cultural. De acuerdo con la Organización Mundial del Turismo, este sector presenta un crecimiento importante en los últimos años y se prevé, que siga creciendo en los próximos. Es necesario entonces, estudiar de qué manera se pueden gestionar los destinos turísticos para ofrecer servicios de calidad garantizando la sostenibilidad. Los Estudios de Capacidad de Carga Turística representan uno de los instrumentos de mayor importancia para lograr estos propósitos, donde a través de un proceso sistemático se analizan variables que tienen influencia directa sobre el territorio y la prestación de servicios turísticos, con el fin de determinar la cantidad de visitantes que puede recibir y/o atender un destino sin alterar de manera significativa sus dinámicas naturales, sociales y culturales

    Electrochemical oxidation of methanol on Pt/(RuxSn1-x)O2 nanocatalyst

    Get PDF
    The Ru-doped SnO2 powder, (RuxSn1-x)O2, with the Sn:Ru atomic ratio of 9:1 was synthesized and used as a support for Pt nanoparticles (30 mass% loading). The (RuxSn1-x)O2 support and Pt/(RuxSn1-x)O2 catalyst were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy (TEM). (RuxSn1-x)O2 was found to be two-phase material consisting of probably solid solution of RuO2 in SnO2 and pure RuO2. The average Pt particle size determined by TEM was 5.3 nm. Cyclic voltammetry of Pt/(RuxSn1-x)O2 indicated good conductivity of the sup-port and displayed usual features of Pt. The results of the electrochemical oxidation of COads and methanol on Pt/(RuxSn1-x)O2 were compared with those on commercial Pt/C and PtRu/C catalysts. Oxidation of COads on Pt/(RuxSn1-x)O2 starts at less positive potentials than on PtRu/C and Pt/C. Potentiodynamic polarization curves and chronoamperometric curves of methanol oxidation indicated higher initial activity of Pt/(RuxSn1-x)O2 catalyst compared to PtRu/C, but also a greater loss in the current density over time. Potentiodynamic stability test of the catalysts revealed that deactivation of the Pt/(RuxSn1-x)O2 and Pt/C was primarily caused by the poisoning of Pt surface by the methanol oxidation residues, which mostly occurred during the first potential cycle. In the case of PtRu/C the poisoning of the surface was minor and deactivation was caused by the PtRu surface area loss. [Projekat Ministarstva nauke Republike Srbije, br. ON-172054

    Konzervirana morska riba na srpskome tržištu: razine cinka, bakra i željeza i njihov doprinos dnevnom unosu ovih esencijalnih metala

    Get PDF
    The aim of this study was to determine the levels of Zn, Cu, and Fe in three canned fish species marketed Serbia to see if they meet recommended daily intake requirements or exceed safety limits. We collected a total of 207 samples of canned tuna, sardine, and mackerel, in oil or tomato sauce and analysed them with inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. The highest levels were obtained for Zn (15.1 mg kg-1) and Cu (1.37 mg kg-1) in sardine in oil and tomato sauce, respectively, and for Fe (18.98 mg kg-1) in mackerel in tomato sauce. Our results keep within the ranges reported by several national food databases and available literature data, with a few exceptions. Our findings also single out canned sardines as the richest source of the three essential elements combined. The estimated daily intake (EDI) of the three essential elements, however, was subpar, and ranged between 0.14 % and 0.72 % of the recommended dietary allowance (RDA) for Zn, Cu, and Fe.Cilj ovoga rada bio je utvrditi razinu cinka, bakra i željeza u trima vrstama ribljih konzervi sa srpskoga tržišta kako bi se ustanovilo zadovoljavaju li zahtjeve za preporučenim dnevnim unosom, ili pak prekoračuju sigurnosne granice. Sadržaj esencijalnih elemenata utvrđen je u ukupno 207 uzoraka konzerve tune, sardine i skuše primjenom masene spektrometrije s induktivno spregnutom plazmom (ICP-MS) nakon kisele digestije uzoraka. Najveći sadržaj cinka (15,1 mg kg-1) utvrđen je u sardini u ulju, bakra (1,37 mg kg-1) u sardini u umaku od rajčice, a željeza (18,98 mg kg-1) u skuši u umaku od rajčice. Dobiveni rezultati su u opsegu vrijednosti za analizirane elemente koje je objavilo nekoliko nacionalnih baza podataka o hrani, kao i u opsegu dostupnih literaturnih podataka, s nekoliko iznimaka. Rezultati istraživanja izdvajaju sardinu u konzervi kao najbogatiji izvor proučavanih esencijalnih elementa. Procijenjeni dnevni unos (EDI) bio je između 0,14 % i 0,72 % preporučenih dnevnih unosa cinka, bakra i željeza. Iako sardina u konzervi, u odnosu na tunu i skušu, doprinosi oko 1,5 puta više preporučenom dnevnom unosu (RDI) esencijalnih elemenata, konzervirana morska riba ne može se smatrati značajnim izvorom cinka, bakra i željeza u prehrani srpskoga stanovništva

    SATURN D6.5 - Final Report

    Get PDF
    The objective of the SATURN (Strategic Allocation of Traffic Using Redistribution in the Network) project is to make novel and credible use of market-based demand-management mechanisms to redistribute air traffic in the European airspace. This reduces congestion and saves the airspace users operational costs. The project is motivated by frequent demand and capacity imbalances in the European airspace network, which are forecast to continue in the near future. The present and foreseen ways of dealing with such imbalances mainly concern strategic and tactical capacity-side interventions, such as resectorisation and opening of more sectors to deal with excess demand. These are followed by tactical demand management measures, if needed. As a result, not only do substantial costs arise, but airspace users are also typically left with no choice but to comply with imposed air traffic flow management measures. The project shows how economic signals could be given to airspace users and air navigation service providers (ANSPs) to improve capacity-demand balancing, airspace design and usage, and what the benefits would be of a centralised planner compared with those of decentralised maximisation of self interests (by the ANSPs and/or airspace users)

    Priprava taložnog kalcijeva karbonata šaržnim i semikontinuiranim postupkom

    Get PDF
    A comparison of the physical-chemical properties of precipitated calcium carbonate (PCC), prepared by batch and semicontinuous processes, is presented. In both processes, PCC, was synthesized by carbonation of slaked lime. In the batch process the experiments were performed by varying the initial mass concentration and temperature, and the semicontinuous process was conducted by varying the initial supersaturation and temperature. Calcite was the only calcium carbonate polymorph that appeared under the experimental conditions investigated. It was found, that in the batch experiments the specific surface area and the average size of calcite particles decreased with the increase of temperature. At the same time, the increase of the initial mass concentration of slaked lime enhanced the degree of precipitate aggregation. PCC prepared by the semicontinuous process, conducted at low temperatures and high supersaturations, was of high specific surface area. By careful tuning of the semicontinuous process parameters, calcite in the form of rhombohedral, scalenohedral or nanosized spherical particles can be producedU ovom su radu uspoređena fizičko-kemijska svojstva taložnog kalcijeva karbonata (TKK) pripravljenog karbonatizacijom vapnenog mlijeka u šaržnom i semikontinuiranom reaktoru. U šaržnom su postupku varirane temperatura i početna masena koncentracija vapnenog mlijeka, dok su u semikontinuiranom mijenjani temperatura i prezasićenost sustava. Pri svim je istraživanim uvjetima nastao kalcit. Utvrđeno je da se specifična površina i prosječni promjer čestica kalcita, pripravljenog šaržnim postupkom, smanjuju s povećanjem temperature, dok se s povišenjem početne masene koncentracije poboljšava stupanj agregiranosti taloga. TKK pripravljen semikontinuiranim postupkom, vođenim pri niskim temperaturama ili visokim prezasićenostima, velike je specifične površine. Odabirom procesnih parametara semikontinuiranog postupka moguće je pripraviti kalcit u obliku romboedarskih, skalenoedarskih ili kuglastih čestica nanometarskih dimenzija
    corecore