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Wyszukujesz frazę "Costa, A." wg kryterium: Autor


Tytuł:
Using symbolic computation in the characterization of frictional instabilities involving orthotropic materials
Autorzy:
Agwa, M. A.
Pinto da Costa, A.
Powiązania:
https://bibliotekanauki.pl/articles/330798.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
Coulomb friction
dynamic instabilities
surface solutions
orthotropic material
tarcie Coulomba
niestabilność dynamiczna
roztwór powierzchniowy
materiał ortotropowy
Opis:
The present work addresses the problem of determining under what conditions the impending slip state or the steady sliding of a linear elastic orthotropic layer or half space with respect to a rigid flat obstacle is dynamically unstable. In other words, we search the conditions for the occurrence of smooth exponentially growing dynamic solutions with perturbed initial conditions arbitrarily close to the steady sliding state, taking the system away from the equilibrium state or the steady sliding state. Previously authors have shown that a linear elastic isotropic half space compressed against and sliding with respect to a rigid flat surface may get unstable by flutter when the coefficient of friction μ and Poisson's ratio ν are sufficiently large. In the isotropic case they have been able to derive closed form analytic expressions for the exponentially growing unstable solutions as well as for the borders of the stability regions in the space of parameters, because in the isotropic case there are only two dimensionless parameters (μ and ν). Already for the simplest version of orthotropy (an orthotropic transversally isotropic material) there are seven governing parameters (μ, five independent material constants and the orientation of the principal directions of orthotropy) and the expressions become very lengthy and literally impossible to manipulate manually. The orthotropic case addressed here is impossible to solve with simple closed form expressions, and therefore the use of computer algebra software is required, the main commands being indicated in the text.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 2; 259-267
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seroprevalence of SARS-CoV-2 and assessment of epidemiologic determinants in Portuguese municipal workers
Autorzy:
Barros Ferreira, Nuno
Pereira, Helena
Pereira, Ana M.
Azevedo, Luís F.
Santos, Mariana
Maranhão, Priscila
Correia, Ricardo
Fonseca, João A.
Canedo, Paulo
da Costa Pereira, Altamiro
Sousa-Pinto, Bernardo
Powiązania:
https://bibliotekanauki.pl/articles/2084912.pdf
Data publikacji:
2022-06-08
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
SARS-CoV-2 infection
COVID-19 pandemic
COVID-19 virus
COVID-19 serodiagnosis
COVID-19 antibody testing
SARS-CoV-2 infection serological testing
Opis:
ObjectivesTo assess the seroprevalence of SARS-CoV-2 antibodies in municipal employees of Northern Portugal during the first pandemic wave (May–June 2020) and its association with potentially related risk factors for infection.Material and MethodsThe authors assessed municipal employees of 2 cities in Northern Portugal, in whom serological tests to SARS-CoV-2 and an epidemiological survey were applied. The authors assessed the proportion of individuals presenting IgM and/or IgG antibodies to SARS-CoV-2, and evaluated the association between having positive serological test results, epidemiologic variables and clinical presentations. Reported symptoms were evaluated on their sensitivity, specificity, and predictive values.ResultsThe authors assessed 1696 employees, of whom 22.0% were firefighters, 10.4% were police officers, 10.3% were maintenance workers, and 8.1% were administrative assistants. The seroprevalence of SARS-CoV-2 infection was 2.9% (95% CI: 2.1–3.7%). Administrative assistants comprised the professional group with highest seroprevalence of SARS-CoV-2 (OR = 1.9 in the comparison with other occupational groups, 95% CI: 0.8–4.3, p = 0.126). The seroprevalence of SARS-CoV-2 infection among those who were in direct contact with COVID-19 patients in their professional activity was 3.9%, compared to 2.7% among those who were not in direct contact with such patients (OR = 1.5, 95% CI: 0.8–2.8, p = 0.222). The highest risk of infection was associated with the presence of a confirmed SARS-CoV-2 infection in the household (OR = 17.4, 95% CI: 8.3–36.8, p < 0.001). Living with a healthcare professional was not associated with a higher risk of infection (OR = 1.0, 95% CI: 0.4–2.5, p = 0.934). Anosmia/dysgeusia was the symptom with the highest positive predictive value (52.2%, 95% CI: 31.8–72.6, p < 0.001) and specificity (99.3%, 95% CI: 98.9–99.7, p < 0.001), while cough was the most prevalent symptom among SARS-CoV-2 seropositive participants (36%).ConclusionsThe authors observed a SARS-CoV-2 seroprevalence of 2.9% among assessed municipal employees. Anosmia/dysgeusia was the COVID-19 symptom which displayed the highest positive predictive value and specificity.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2022, 35, 3; 297-307
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Winter Cover Crop Biomass on Summer Weed Emergence and Biomass Production
Autorzy:
Bittencourt, H.H.
Lovato, P.E.
Comin, J.J.
Lana, M.A.
Altieri, M.A.
Costa, M.D.
Gomes, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/65024.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
A greenhouse assay was carried out to evaluate the effect of winter cover crop residues on spontaneous plants that commonly occur on summer annual fields in Southern Brazil. Dry shoot residues of rye (Secale cereale), vetch (Vicia villosa), fodder radish (Raphanus sativus), and a mix of the three species, were applied over pots that had been seeded with alexandergrass (Brachiaria plantaginea), hairy beggarticks (Bidens pilosa), wild poinsettia (Euphorbia heterophylla), and morning glory (Ipomoea grandifolia) at four different depths (0, 1, 2, or 4 cm). Plant emergence and biomass production were measured. Residues of rye reduced the emergence of B. plantaginea, while vetch diminished I. grandifolia and B. plantaginea emergence. Fodder radish reduced emergence of I. grandifolia. The mix of cover crops reduced emergence of I. grandifolia, B. plantaginea, and B. pilosa. None of the cover crops differed from the control on E. heterophylla emergence. The lowest yields in spontaneous plant shoot biomass were obtained from the cover with rye + vetch + fodder radish. The lowest values of root biomass occurred under cover with rye, fodder radish or the mix. Use of vetch residues decreased emergence of B. plantaginea and I. grandifolia, but enhanced biomass accumulation by the latter.
Źródło:
Journal of Plant Protection Research; 2013, 53, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust control of depth of anesthesia based on H∞ design
Autorzy:
Caiado, D. V.
Lemos, J. M.
Costa, B. A.
Powiązania:
https://bibliotekanauki.pl/articles/229439.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
depth of anesthesia
model uncertainty
robust control feedback
H∞ design
μ-synthesis
Opis:
This paper presents a case study on the design of a robust controller for the depth of anesthesia (DoA) induced by the drug propofol. This process is represented by a linear model together with a non-parametric uncertainty description that is evaluated using a patient model bank with 20 patients undergoing sedation. By using H∞ methods, the controller is aimed to comply with robust stability and performance specifications for the class of patient models considered. A minimization problem of sensitivity and complementary sensitivity is made to design the controller. The controller that results from this procedure is approximated by a controller with a lower order, that in turn is redesigned in discrete time for computer control application. The resulting controller is evaluated in simulations using a realistic nonlinear model of DoA.
Źródło:
Archives of Control Sciences; 2013, 23, 1; 41-59
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between clinical efficacy on pruritus and serum interleukin-31 levels in dogs with atopic dermatitis treated with lokivetmab
Autorzy:
Calesso, J.R.
Marques, V.S.
de Carvalho, O.V.
Costa-Val, A.P.
Powiązania:
https://bibliotekanauki.pl/articles/16647579.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
atopic dermatitis
interleukin-31
lokivetmab
monoclonal antibody
pruritus
Opis:
Studies on serum interleukin (IL)-31 levels in dogs with atopic dermatitis (AD) and their correlation with disease severity are limited. To the author’s knowledge, there are no studies that measured serum IL-31 in dogs treated with lokivetmab injections, a selective inhibitor of this key cytokine in pruritus. The aim of the study was to evaluate serum IL-31 levels in dogs treated with lokivetmab and correlate it with the severity of canine atopic dermatitis using the pruritus visual analog scale (pVAS) and canine atopic dermatitis extent and severity index (CADESI-04). Ten client-owned dogs diagnosed with AD received two injections of lokivetmab four weeks apart. Disease severity was assessed using the pVAS and CADESI-04 scores before and after both injections. In addition, canine serum IL-31 levels were measured at the same moments. Serum IL-31 was detected in all dogs in the study. There was a significant reduction in pVAS scores and serum IL-31 after administrations. However, there was no difference in CADESI-04 scores, and there was no significant correlation between CADESI-04 scores and serum IL-31 in dogs diagnosed with AD. Nonetheless, a significant positive correlation was observed between the pVAS scores and serum IL-31 levels with lokivetmab therapy, which reinforces the role of IL-31 in the pathogenesis of pruritus in dogs with AD. The data presented here provide further evidence that IL-31 is directly involved in pruritus pathogenesis in dogs with AD. In addition, blocking IL-31 has a significant antipruritic effect, but has no influence on skin lesion severity and extension.
Źródło:
Polish Journal of Veterinary Sciences; 2023, 26, 2; 231-238
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an irradiation system for a small size continuous run multipurpose gamma irradiator
Autorzy:
Calvo, W. A. P.
Rela, P. R.
Napolitano, C. M.
Kodama, Y.
Omi, N. M.
da Costa, F.
de Andrade e Silva, L. G.
Powiązania:
https://bibliotekanauki.pl/articles/148041.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
multipurpose irradiator
gamma irradiator
compact irradiator
cobalt-60 irradiator
gamma facility
Opis:
The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is a product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 PBq. The performed qualification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process qualification. The initial load of the multipurpose irradiator was 3.4 PBq with 13 cobalt-60 sources model C-188, supplied by MDS Nordion – Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The polymethylmetacrylate (PMMA) dosimeter system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning with dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma irradiators available on the market.
Źródło:
Nukleonika; 2009, 54, 2; 93-97
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, characterization and catalytic properties of SAPO-11 molecular sieve synthesized in hydrothermal media using di-isopropylamine as template
Autorzy:
Chellappa, T.
Costa, M. J. F.
Nascimento, W. A.
Ferreira De Lima, L.
Bassan, I. A.
Tavares, M.
Fernandes, V. J.
Menezes, A.
Guilherme Meira, L.
Telesforo Nóbrega De Medeiros, J.
Maribondo Do Nascimento, R.
Powiązania:
https://bibliotekanauki.pl/articles/200372.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microporous materials
SAPO-11
characterization
catalytic activity
molecular sieves
Opis:
A microporous SAPO-11 Molecular sieve was successfully synthesized by the hydrothermal method, using a single agent, as an organic template: di-isopropylamine (DIPA). The obtained solid was calcined at 550C for three hours, after which the flow of nitrogen was exchanged for that of synthetic air and submitted for another ten hours of calcination, so as to remove the single agent: di-isopropylamine, which after the removal of the template could be observed by the high crystallization of the sample. Furthermore, the molecular sieve was characterized by XRD, SEM, TG-DTG and N2 adsorption desorption (BET analysis). The obtained catalyst proved to have a high potential catalytic activity and selectivity, through the obtained characterization results, exhibiting good hydrothermal stability. The catalytic performance of SAPO-11 was tested by the deactivation/regenerability of the coked sample, furthered by cracking of n-hexane reaction and high olefins selectivity was obtained.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 3; 481-488
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of isometric strength of the shoulder rotators in swimmers using a handheld dynamometer : a reliability study
Autorzy:
Coinceicao, A.
Parraca, J.
Marinho, D.
Costa, M.
Louro, H.
Silva, A.
Batalha, N.
Powiązania:
https://bibliotekanauki.pl/articles/306193.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
siłomierz
pływanie
młodzi pływacy
handheld dynamometer
prone position
young swimmers
swimming
Opis:
The purpose of this study was to determine the reliability of shoulder isometric strength assessment using the microfet 2™ dynamometer in adolescent swimmers. Methods: Twenty-nine participants (16.2 ± 1.2 years old; 59.05 ± 6.98 kg of body mass) were tested using the microfet 2™ dynamometer. Swimmers performed an isometric strength test (IST) in two distinct occasions with 7 days apart in order to calculate the reliability. All participants were asked to perform a maximal isometric contraction from the external and internal shoulder rotators in a prone body position. Results: The external and internal shoulder rotators showed an excellent intraclass correlation coefficients for both shoulders, with more than 0.90 and a low percentage of method error variation. The external/internal ratios reliability was good in dominant (ICC 0.80) and non-dominant (ICC 0.81) shoulders. The reliability using Bland–Altman method showed that systematic errors (mean difference between test-retest) were nearly zero and the 95% limits of agreement narrow, indicating a good reliability. Conclusions: It can be concluded that microfet 2™ is a reliable apparatus for measuring the strength of the external and internal rotation of the shoulder in swimmers. Its light weight and easy portable characteristics can help swimming coaches monitoring specific dry-land strength training programs for their swimmers.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 113-119
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Involvement of carbohydrates and antioxidant enzymes in the oxidative balance during drought and recovery: the eucalyptus case
Autorzy:
Correia, B.
Silva, S.
Jesus, C.
Valledor, L.
Dias, M.
Costa, A.
Santos, C.
Pinto, G.
Powiązania:
https://bibliotekanauki.pl/articles/79853.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
carbohydrate
antioxidative enzyme
oxidative balance
drought
recovery
cellular function
abiotic stress
reactive oxygen species
eucalyptus
Eucalyptus globulus
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of disinfectant fogging procedure on dust, ammonia concentration, aerobic bacteria and fungal spores in a farrowing-weaning room
Autorzy:
Costa, A.
Colosio, C.
Gusmara, C.
Sala, V.
Guarino, M.
Powiązania:
https://bibliotekanauki.pl/articles/50123.pdf
Data publikacji:
2014
Wydawca:
Instytut Medycyny Wsi
Opis:
Introduction and Objective. In the last decades, large-scale swine production has led to intensive rearing systems in which air quality can be easily degraded by aerial contaminants that can pose a health risk to the pigs and farm workers. This study evaluated the effects of fogging disinfectant procedure on productive performance, ammonia and dust concentration, aerobic bacteria and fungal spores spreading in the farrowing–weaning room. Materials and Method. This trial was conducted in 2 identical farrowing-weaning rooms of a piggery. In both rooms, 30 pregnant sows were lodged in individual cages. At 75 days of age, the piglets were moved to the fattening room. In the treated room, with the birth of the first suckling-pig, the fogging disinfection with diluted Virkon S was applied once a day in the experimental room per 15 minutes at 11:00. The fogging disinfectant treatment was switched between rooms at the end of the first trial period. Temperature, relative humidity, dust (TSP-RF fractions and number of particles), ammonia concentration and aerial contaminants (enterococci, Micrococcaeae and fungal spores) were monitored in both rooms. Results. Ammonia concentration reduction induced by fogging disinfection was estimated 18%, total suspended particles and the respirable fraction were significantly lower in the experimental room. Fungal spores resulted in a significant reduction by the fogging procedure, together with dust respirable fraction and fine particulate matter abatement. Conclusions. The fogging disinfection procedure improved air quality in the piggery, thereby enhancing workers and animals health.
Źródło:
Annals of Agricultural and Environmental Medicine; 2014, 21, 3
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shape memory process in resorbable polymers: effect on surface properties and cell adhesion
Autorzy:
Costa, A. M.
Ferreira, A. S.
Posadowska, U.
Krok, M.
Smola, A.
Dobrzyński, P.
Pamuła, E.
Powiązania:
https://bibliotekanauki.pl/articles/286068.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
shape memory
PLGA
tissue regeneration
foil
Opis:
The objectives of this study were to confirm the shape memory behavior of two new bioresorbable terpolymers (L-lactide, glycolide, and trimethylene carbonate: L-PLGTMC and B-PLGTMC), to follow the influence of the shape memory process on their surface properties and to test their cytocompatibility using osteoblast-like cells. For this purpose, foils of both terpolymers were prepared. The terpolymers' ability to recover up to 92-93% of the memorized shape within 10 seconds was obtained. The influence of shape memory process on the surface properties was assessed by water contact angle (WCA) measurement and atomic force microscopy (AFM) and the results suggested that both terpolymers preserved the hydrophilicity after recovery and also that B-PLGTMC polymer was rougher than L-PLGTMC (about 9 folds more). The AFM pictures showed the presence of spherical shape hills on the B-PLGTMC foil surface which after the stretching procedure became oriented toward the direction of the applied load. The terpolymers were seeded on both sides (Top and Bottom faces) with human MG63 osteoblast-like cells. Cell viability was assessed after 1, 3 and 7 days, using MTT assay. Results revealed an increasing number of metabolically active cells with the incubation time, suggesting, together with nitric oxide (NO) level determination, the cytocompatibility of both terpolymers. Cell spreading and morphology were investigated by H&E staining and obtained results corresponded well with ones of MTT and NO.
Źródło:
Engineering of Biomaterials; 2012, 15, 114; 8-11
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Full-fledged temporal processing : bridging the gap between deep linguistic processing and temporal extraction
Autorzy:
Costa, F.
Branco, A.
Powiązania:
https://bibliotekanauki.pl/articles/103861.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Podstaw Informatyki PAN
Tematy:
temporal processing
temporal extraction
tense
aspect
hybrid approaches
deep linguistic processing
shallow linguistic processing
Opis:
The full-fledged processing of temporal information presents specific challenges. These difficulties largely stem from the fact that the temporal meaning conveyed by grammatical means interacts with many extra-linguistic factors (world knowledge, causality, calendar systems, reasoning). This article proposes a novel approach to this problem, based on a hybrid strategy that explores the complementarity of the symbolic and probabilistic methods. A specialized temporal extraction system is combined with a deep linguistic processing grammar. The temporal extraction system extracts eventualities, times and dates mentioned in text, and also temporal relations between them, in line with the tasks of the recent TempEval challenges; and uses machine learning techniques to draw from different sources of information (grammatical and extra-grammatical) even if it is not explicitly known how these combine to produce the final temporal meaning being expressed. In turn, the deep computational grammar delivers richer truth-conditional meaning representations of input sentences, which include a principled representation of temporal information, on which higher level tasks, including reasoning, can be based. These deep semantic representations are extended and improved according to the output of the aforementioned temporal extraction module. The prototype implemented shows performance results that increase the quality of the temporal meaning representations and are better than the performance of each of the two components in isolation.
Źródło:
Journal of Language Modelling; 2013, 1, 1; 97-154
2299-856X
2299-8470
Pojawia się w:
Journal of Language Modelling
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can concurrent teaching promote equal biomechanical adaptations at front crawl and backstroke swimming?
Autorzy:
Costa, M. J.
Barbosa, T. M.
Morais, J. E.
Miranda, S.
Marinho, D. A.
Powiązania:
https://bibliotekanauki.pl/articles/307054.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ekspertyza
kinematyka ruchu
pływak
expertise
kinematics
swimmer
Opis:
Purpose: The biomechanical adaptations in front crawl and backstroke swimming, as influenced by the implementation of a concurrent teaching programme were analysed. Methods: Sixteen participants (19.75 ± 1.13 years) underwent a 30 weeks intervention characterized by an increasing complexity to accomplish motor skills in the following order: (i) lower limbs propulsion; (ii) lower limbs propulsion synchronized with breathing cycle; (iii) lower limbs propulsion synchronized with one upper limb action; (iv) lower limbs propulsion synchronized with both breathing cycle and one upper limb action; (v) full swimming stroke; (vi) motor trajectory of the arms stroke. Performance and biomechanics were measured at front crawl and backstroke during three time points throughout the programme. Results: There were improvements in performance over time at front crawl (21.49 s to 19.99 s, p < 0.01) and backstroke (27.15 s to 24.60 s, p = 0.01). Significant improvements were found for velocity at front crawl (1.13 m/s to 1.22 m/s, p < 0.01) and backstroke (0.92 m/s to 1.00 m/s, p < 0.01). Stroke frequency increased at backstroke (0.64 to 0.73 Hz, p = 0.01), while the intra-cyclic variation of the velocity decreased at front crawl (0.13 to 0.12%, p = 0.02). There was also a moderate-high inter-subject variability in response to the programme. Conclusions: These findings prove that a programme of 30 weeks teaching concurrently front crawl and backstroke is effective to promote similar biomechanical adaptations in low-tier swimmers. However, each subject shows an individual response to better adapt the biomechanical actions and to reach a higher level of expertise.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 81-88
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study about the measurement method of the homogeneity of radioactivity along an iridium-192 wire used in brachytherapy
Autorzy:
Costa, O. L.
Calvo, W. A. P.
Zeituni, C. A.
Rostelato, M. E. C. M.
Moura, J. A.
Feher, A.
Souza, C. D.
Somessari, S. L.
Powiązania:
https://bibliotekanauki.pl/articles/148238.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iridium-192
iridium wire
low dose rate brachytherapy
quality control
cancer treatment
radioactive sources production
Opis:
The Nuclear and Energy Research Institute has produced, since 1998, iridium-192 wires used in low dose rate brachytherapy. In the paper the authors studied the influence of wire profile on the homogeneity distribution of radioactivity of iridium-192 along the wire. The authors propose the improvements in the quality control procedure that will provide more accurate measurement data and suggest changes in control devices.
Źródło:
Nukleonika; 2014, 59, 1; 37-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reversible electron charge transfer in single-wall carbon nanotubes
Autorzy:
Costa, S.
Bachmatiuk, A.
Borowiak-Palen, E.
Powiązania:
https://bibliotekanauki.pl/articles/779706.pdf
Data publikacji:
2008
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
nanorurki węglowe jednościenne
domieszkowanie
Raman
SWCNT
doping
Opis:
Single-wall carbon nanotubes (SWCNT) have proved to be very special materials due to their unique electronic properties. Over the last years many scientists have dedicated their research to the study of the these materials as an electronic system. Amphoteric doping effects (n-type and p-type), which can be reversed, became a very popular way of manipulating the optic and electronic properties of carbon nanotubes. In the particular case of SWCNT, the most common and widely used procedure, which changes their properties, is acid treatment applied as a purification procedure. The effect of the addition of this kind of the dopant has been widely studied but not fully understood so far. Here, we present a study, of two kinds of SWCNT, produced within different techniques: (i) chemical vapors deposition and (ii) laser ablation. The main difference between the two types is the diameter distribution of the obtained materials, which is broad in the first technique and narrow in the second. After the acid treatment it is possible to observe a diameter sensitive doping effect on both samples. Resonance Raman spectroscopy, optical absorption spectroscopy (OAS) in UV/Vis/NIR and the Fourier transform middle-infrared (FTIR) spectroscopy have been applied for the characterization of the samples.
Źródło:
Polish Journal of Chemical Technology; 2008, 10, 2; 1-4
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

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