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Tytuł:
The influence of aging on the isometric torque sharing patterns among the plantar flexor muscles
Autorzy:
Oliveira, L. F.
Verneque, D.
Menegaldo, L. L.
Powiązania:
https://bibliotekanauki.pl/articles/306726.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
starzenie się
EMG
zgięcie podeszwowe
mięsień trójgłowy łydki
aging
triceps surae
plantar flexion
torque sharing
Opis:
Purpose: Physiological cross-sectional area (PCSA) reduction of the triceps surae (TS) muscles during aging suggests a proportional loss of torque among its components: soleus, medial and lateral gastrocnemii. However, direct measurements of muscle forces in vivo are not feasible. The purpose of this paper was to compare, between older and young women, isometric ankle joint torque sharing patterns among TS muscles and tibialis anterior (TA). Methods: An EMG-driven model was used for estimating individual muscle torque contributions to the total plantar flexor torque, during sustained contractions of 10% and 40% of maximum voluntary contraction (MVC). Results: Relative individual muscle contributions to the total plantar flexion torque were similar between older and young women groups, for both intensities, increasing from LG, MG to SOL. Muscle strength (muscle torque/body mass) was significantly greater for all TS components in 40% MVC contractions. Increased TA activation was observed in 10% of MVC for older people. Conclusions: Despite the reduced maximum isometric torque and muscle strength, the results suggest small variations of ankle muscle synergies during the aging process.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 41-45
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and design of a MOSFET-only wideband balun LNA
Autorzy:
Bastos, I.
Oliveira, L. B.
Goes, J.
Silva, M.
Powiązania:
https://bibliotekanauki.pl/articles/397861.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
tranzystor polowy MOS-tylko obwody
redukcja hałasu
CMOS LNAs
MOSFET-only circuits
noise cancelling
wideband LNA
Opis:
In this paper we present a MOSFET-only implementation of a balun LNA. This LNA is based on the combination of a common-gate and a common-source stage with cancellation of the noise of the common-gate stage. In this circuit, we replace resistors by transistors, to reduce area and cost, and to minimize the effect of process and supply variations and mismatches. In addition, we obtain a higher gain for the same voltage drop. Thus, the LNA gain is optimized and the noise figure (NF) is reduced. We derive equations for the gain, input matching and NF. The performance of this new topology is compared with that of a conventional LNA with resistors. Simulation results with a 130 nm CMOS technology show that we obtain a balun LNA with a peak gain of 20.2 dB (about 2 dB improvement), and a spot NF lower than 2.4 dB. The total power consumption is only 4.8 mW for a bandwidth higher than 6 GHz.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 3; 241-248
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Co-design of a low-power RF receiver and piezoelectric energy harvesting power supply for a Wireless Sensor Node
Autorzy:
Mancelos, N
Correia, J
Oliveira, J. P.
Oliveira, L. B.
Powiązania:
https://bibliotekanauki.pl/articles/398018.pdf
Data publikacji:
2014
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
CMOS RF analog front-end
low-voltage wideband balun LNA
passive mixer
piezoelectric energy harvesting
active full bridge rectifier
LDO regulator
układ analogowy CMOS
balun szerokopasmowy
mikser pasywny
energia piezoelektryczna
prostownik aktywny
prostownik mostkowy
regulator LDO
Opis:
A low-voltage RF CMOS receiver front-end and an energy harvesting power circuit for a piezoelectric source are presented as a co-designed solution for a Wireless Sensor Node. A MOSFET-only Wideband balun LNA with noise cancelling and a 0.6 V supply voltage is designed in conjunction with a passive mixer. The passive mixer operates in current mode, allowing a minimal introduction of voltage noise and a good linearity. The receiver front-end reaches a total voltage conversion gain of 31 dB, a 0.1-5.2 GHZ bandwidth, an IIP3 value of -1.35 dBm, and a noise figure inferior to 9 dB. The total power consumption is 1.95 mW. The energy harvesting power circuit consists of an active full bridge cross-coupled rectifier followed by a low-dropout (LDO) regulator, and it is able to guarantee a power output of 6 mW with a regulated output voltage of 0.6 V, for typical vibration patterns.
Źródło:
International Journal of Microelectronics and Computer Science; 2014, 5, 4; 136-143
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cascode amplifiers with low-gain variability and gain enhancement using a body-biasing technique
Autorzy:
Pereira, N
Oliveira, L. B.
Goes, J.
Oliveira, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/398063.pdf
Data publikacji:
2013
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
amplifier
body-biasing
cascode
CMOS analog circuits
PVT compensation
wzmacniacz
kaskoda
układy analogowe CMOS
kompensacja PVT
Opis:
This paper presents a simple circuit technique to reduce gain variability with PVT variations in cascode amplifiers using a body-biasing scheme, while enhancing the overall gain of the amplifier. Simulation results of a standard telescopic-cascode amplifier, in two different nanoscale CMOS technologies (130 nm and 65 nm) show that the proposed compensated circuit amplifier exhibits a (DC) gain variability smaller (below ± 0.5 dB) than the original (uncompensated) circuit, while reaching a gain enhancement of about 3 dB. The required auxiliary biasing circuit dissipates around 5% of the main amplifier circuit.
Źródło:
International Journal of Microelectronics and Computer Science; 2013, 4, 3; 98-102
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lower Toarcian organic-rich sediments from the Tuscan Succession (Northern Apennines, Italy): preliminary results
Autorzy:
Perilli, N.
Rodrigues, R.
Veiga de Oliveira, L.
Catanzariti, R.
Powiązania:
https://bibliotekanauki.pl/articles/2061357.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
black shales
Early Toarcian
calcareous nannofossils
Tuscan Nappe
Northern Apennines
Italy
Opis:
For the first time is here documented the presence of Lower Toarcian black shales in the lower portion of the Calcari e marne a Posidonia (Posidonia Marls auctt.) belonging to the Tuscan Nappe. It consists of alternations of 30 cm to 5 m thick black laminated marlstone and marly claystone, with TOC values ranging from 0.43% to 2.49%. Based on calcareous nannofossils, the basal portion of the Calcari e marne a Posidonia spans the Lotharingius hauffii to Carinolithus superbus zones, and the organic-rich interval lies within the Carinolithus superbus Zone.
Źródło:
Volumina Jurassica; 2009, 7, 1; 55-65
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and design of CMOS coupled multivibrators
Autorzy:
Casaleiro, J.
Lopes, H. F.
Oliveira, L. B.
Filanovsky, I.
Powiązania:
https://bibliotekanauki.pl/articles/397859.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
multiwibrator
CMOS oscillator
multivibrator
quadrature outputs
van der Pol oscillator
WMTS appications
Opis:
In this paper a wideband MOS quadrature oscillator constituted by two multivibrators is presented. Two different forms of coupling, named here as soft and hard, are investigated. Simulations are performed in a 0.13 žm CMOS technology to obtain the tuning range, the synchronization transients, and the influence of mismatches in timing capacitors and charging currents on synchronization. It is found that hard coupling reduces the quadrature error (about 1°, with 5% mismatches in timing capacitors and charging currents) and results in a low phase-noise (about 2 dB improvement) with respect to soft coupling. Either a single multivibrator or coupled multivibrators can be locked to an external synchronizing harmonic frequency, and the locking range is investigated by simulations. The simulations are done for oscillators covering the WTMS frequency bands.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 3; 249-256
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Simplified Design Methodology for MOSFET-Only Wideband Mixer
Autorzy:
Ortigueira, E.
Bastos, I.
Oliveira, L. B.
Oliveira, J. P.
Goes, J.
Powiązania:
https://bibliotekanauki.pl/articles/227194.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CMOS mixers
MOSFET-only circuits
Gilbert cell
active mixers
wideband mixers
Opis:
In this paper we present a MOSFET-only implementation of a wideband Gilbert Cell. The circuit uses a commongate topology for a wideband input match, capable to cover the Wireless Medical Telemetry Service (WMTS) frequency bands of 600 MHz and 1.4 GHz. In this circuit the load resistors are replaced by transistors in triode region, to reduce area and cost, and minimize the effects of process and supply variations and mismatches. In addition, we obtain a higher gain for the same DC voltage drop, with a reduced impact on the noise figure (NF). The performance of this topology is compared with that of a conventional mixer with load resistors. Simulation results show that a peak gain of 20.6 dB (about 6 dB improvement) and a NF about of 11 dB for the 600 MHz band. The total power consumption is 3.6 mW from a 1.2 V supply.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 4; 503-509
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultra-low-voltage LNA with high gain and low noise figure
Autorzy:
Bastos, I.
Oliveira, L. B.
Oliveira, J. P.
Goes, J.
Silva, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/397785.pdf
Data publikacji:
2013
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
LNA
CMOS
noise cancellation
redukcja szumów
Opis:
We present a balun LNA with noise and distortion cancellation using double feedforward. A common-gate and a common-source stage are combined, and their resistive loads are replaced by transistors biased close to saturation to allows low supply voltage, without gain degradation. The proposed feedforward boosts the LNA gain and reduces the noise figure (NF). Simulation results with a 130 nm CMOS technology show that the gain is up to 24 dB and the NF is below 3.2 dB. The total power dissipation is 2.25 mW, leading to an FoM of 6.4 mW-1 with 0.6 V supply.
Źródło:
International Journal of Microelectronics and Computer Science; 2013, 4, 3; 124-128
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal assisted switching magnetic tunnel junctions as FPGA memory elements
Autorzy:
Silva, V.
Fernandes, J. R.
Oliveira, L. B.
Neto, H. C.
Ferreira, R.
Freitas, S.
Freitas, P. P.
Powiązania:
https://bibliotekanauki.pl/articles/397855.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
MRAM (oporność magnetyczna pamięci o dostępie swobodnym)
MTJ (magnetyczny tunel połączeń)
pisanie projektów (programów)
FIMS (pole indukowane magnetycznym przełącznikiem)
MRAM (magnetoresistive random access memory)
MTJ (magnetic tunnel junction)
writing schemes
FIMS (field induced magnetic switching)
TAS (thermal assisted switching)
STT
Opis:
This paper presents our research and development work on new circuits and topologies based on Magnetic RAM for use as configuration memory elements of reconfigurable arrays. MRAM provides non volatility with cell areas and with access speeds comparable to those of SRAM and with lower process complexity than FLASH memories. The new memory cells take advantage of the Thermal Assisted Switching (TAS) writing technique to solve the drawbacks of the more common Field Induced Magnetic Switching writing technique. The CMOS circuit structures to implement the main components for reading and writing the MTJ cells have been developed, characterized and evaluated. A scaled down prototype of a coarse grain reconfigurable array that employs the TAS-MRAM elements as configuration memory has been designed and electrically simulated pre- and post- layout. The results obtained for all the circuit elements, namely the storage cells and the current generators, indicate that the new configuration memory cells can provide a very promising technological solution for run-time reconfigurable hardware devices. The prototype has been manufactured using a standard process 0.35μm 4-Metal CMOS process technology and should be under test in the foreseeable future.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 1; 31-36
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hypertonic saline solution (NaCl 7.2%) enhances renal excretion of acids in cattle with acute ruminal lactic acidosis
Autorzy:
Rodrigues, F.A.M.L.
Minervino, A.H.H.
Barrêto Júnior, R.A.
Reis, L.F.
Ferreira, R.N.F.
Mori, C.S.
Oliveira, F.L.C.
Sousa, R.S.
Powiązania:
https://bibliotekanauki.pl/articles/2087583.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steers
ruminal lactic acidosis
hypertonic saline solution
Źródło:
Polish Journal of Veterinary Sciences; 2019, 1; 37-42
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tanystropheid archosauromorphs in the Lower Triassic of Gondwana
Autorzy:
De Oliveira, T.M.
Oliveira, D.
Schultz, C.L.
Kerber, L.
Pinheiro, F.L.
Powiązania:
https://bibliotekanauki.pl/articles/23531.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Tanystropheidae is a clade of early archosauromorphs with a reported distribution ranging from the Early to the Late Triassic of Asia, Europe, and North America. Although some specimens with possible tanystropheid affinities from the Lower Triassic beds of Brazil have been previously attributed to “Protorosauria”, little is known about the tanystropheid record in Gondwana. Here, two new and one previously reported specimen from the Sanga do Cabral Formation (Induan–Olenekian) of Brazil are described and interpreted as ?Tanystropheidae. These records, together with other tetrapods previously reported for the Sanga do Cabral Formation, increase the knowledge of the biotic diversification during the beginning of the Triassic. This contribution reinforces that the archosauromorph diversification occurred shortly after the Permo-Triassic extinction, making the Sanga do Cabral Formation an important unit for the study of early Mesozoic faunas.
Źródło:
Acta Palaeontologica Polonica; 2018, 63, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional morphology and biomechanics of the cynodont Trucidocynodon riograndensis from the Triassic of Southern Brazil: Pectoral girdle and forelimb
Autorzy:
de Oliveira, T.V.
Schultz, C.L.
Powiązania:
https://bibliotekanauki.pl/articles/20204.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
functional morphology
biomechanics
cynodont
Trucidocynodon riograndensis
Cynodontia
Trucidocynodon
limb posture
Carnian
Triassic
Brazil
pectoral girdle
forelimb
Opis:
Non-mammalian cynodonts provide insights on several points about mammalian evolution, such as the postural change and locomotory advances within the group. Unfortunately, complete skeletons of Triassic cynodonts are rather uncommon and where more complete specimens are found they can offer a global vision on some traits not available from partial specimens. This is the case of the cynodont Trucidocynodon riograndensis, from the Triassic of Brazil, that has preserved its forelimbs providing some insights into locomotory properties. The movements between interclavicle and clavicle must have been limited, as such as those occurring between the latter and the scapulocoracoid although the long acromion process of this should have permitted a greater degree of freedom. Some of the more significant movements were those on the shoulder joint, in which the maximum adduction should have been ca. 35º relative to the parasagittal plane and the greater abduction ca. 55º. The maximum adduction occurred when the humerus was in the more retracted position during stride and the variation in the adduction/abduction should have been significant to the limb posture during its recovery stroke. The long olecranon and the distal overlapping between radius and ulna suggest the predominance of simple flexion/extension on the forearm without significant pronation/supination. The poorly preserved hand suggests that Trucidocynodon could have evolved a slight semidigitigrad condition in its forelimbs. All these features give to this cynodont an important role in the evolution of the mammalian locomotory properties indicating that some features, such as the possibility of greater humeral adduction, evolved early in cynodont lineage.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monogenoidea parasites of Cichla monoculus and Cichla pinima (Osteichthyes: Cichlidae), sympatric fish in lower Tapajós River, Northern Brazil
Autorzy:
Oliveira, M.S.B.
Adriano, E.A.
Tavares-Dias, M.
Correa, L.L.
Powiązania:
https://bibliotekanauki.pl/articles/6677.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Parazytologiczne
Źródło:
Annals of Parasitology; 2019, 65, 4
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biofilm - formation by Staphylococcus aureus and Staphylococcus epidermidis isolates from subclinical mastitis in conditions mimicking the udder environment
Autorzy:
Seixas, R.
Varanda, D.
Bexiga, R.
Tavares, L.
Oliveira, M.
Powiązania:
https://bibliotekanauki.pl/articles/30529.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Staphylococcus is the genus most commonly isolated from bovine mastitis in many countries. It may express several virulence factors including biofilm formation, which may protect the bacterial community from antimicrobials’ action, preventing these compounds from reaching its interior, where they reach subinhibitory concentrations (subMIC). Most biofilm production assays are performed in static conditions, while studies regarding antimicrobial resistance usually do not resemble the udder environment because they are performed at high concentrations. In this study we evaluated the influence of dynamic conditions and media, including Mueller Hinton Broth (MHB) and UHT whole milk (WM), as well as the effect of subMIC concentrations of five different antimicrobial agents on biofilm formation by staphylococci isolated from subclinical mastitis. Results suggest that dynamic conditions and media may influence biofilm formation and revealed that milking simulation may significantly increase biofilm production. Sub- MIC concentrations decrease biofilm formation in MHB but increase in WM, suggesting a protective role of milk against antimicrobial compounds’ action. Therefore, in vitro conditions that simulate the udder environment and in vivo conditions should be included as one of the parameters in evaluation of biofilm producing strains, in order to provide more reliable results.
Źródło:
Polish Journal of Veterinary Sciences; 2015, 18, 4
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrospinning of polymeric fibres: an unconventional view on the influence of surface tension on fibre diameter
Elektroprzędzenie włókien polimerowych – niekonwencjonalny pogląd na wpływ naprężenia powierzchniowego na średnice włókien
Autorzy:
Araújo, E. S.
Nascimento, M. L. F.
de Oliveira, H. P.
Powiązania:
https://bibliotekanauki.pl/articles/232610.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electrospinning
polymeric fibres
Taylor-cone
surfactant
surface tension
elektroprzędzenie
włókna polimerowe
napięcie powierzchniowe
Opis:
The production of regular and bead-free electrospun polymeric fibres requires an adequate combination of different parameters applied in the experimental setup viz. voltage for electrodeposition, viscosity of the solution, density of the polymeric support, the distance between electrodes and the geometry of the spinneret. Determination of the physical balance of forces on the droplet during fibre production was explored and provides relevant theoretical information about the surface tension and radius of polymeric fibres. Based on these predictions, we prepared polymeric electropun fibres of poly (vinyl alcohol), poly (vinyl pyrrolidone) and Eudragit® L100 in order to analyse non-conventional physical properties of experimental systems such as droplet stiffness and their influence on the diameter of resulting fibres.
Produkcja za pomocą elektroprzędzenia regularnych włókien polimerowych, wolnych od zgrubień wymaga dobrania odpowiedniej kombinacji różnych parametrów stanowiska przędącego takich jak np. napięcie między elektrodami, lepkość roztworu przędzalniczego, gęstość, odległość pomiędzy elektrodami i geometria układu przędącego. Badano fizycznie określony balans sił działający na wypychaną kroplę roztworu podczas tworzenia włókna. Badania eksperymentalne dostarczyły odpowiednich teoretycznych informacji o naprężeniu powierzchniowym i średnicy tworzonych włókien polimerowych. W oparciu o uzyskane informacje przygotowano elektroprzędzenie włókien z alkoholu poliwinylowego, alkoholu poliwinylopirolidowego i preparatu Eudragit® L100. Następnie na podstawie wcześniejszych rozważań i uzyskanych wyników eksperymentalnych przeprowadzono analizę wpływu poszczególnych czynników na średnicę otrzymywanych włókien.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 1 (115); 22-29
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Triton X-100 on PVA Fibres Production by the Electrospinning Technique
Wpływ Triton X-100 na produkcję włókien PVA metodą elektroprzędzenia
Autorzy:
Araújo, E. S.
Nascimento, M. L. F.
de Oliveira, H. P.
Powiązania:
https://bibliotekanauki.pl/articles/233825.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
electrospinning
poly(vinyl alcohol) fibres
surfactant
beads
fibre production
elektroprzędzenia
alkohol poliwinylowy
włókna
środki powierzchniowo czynne
zgrubienia w produkcji włókien
Opis:
Electrospinning represents a low cost technique applied in the production of micro- and nano-fibres. The use of poly(vinyl alcohol) as supporting matrix in aqueous solution for fibre deposition introduces important advantages related with drug release (based on the low toxicity of polymer). On the other side, imperfections of resulting fibres (bead formation) represents an impediment to be circumvented. The introduction of non ionic surfactant (triton X-100) circumvents bead formation and improves the homogeneity of fibre, as verified in the analysis of thermal, structural and morphological properties of PVA net. The results indicate that minimal dispersion of triton X-100 in solution (in the order of 1 wt%) affects the circularity of beads, while at 10 wt% a reduction in the defect concentration in the order of five times is verified with a reasonable reduction in the diameter of the remaining defects and improvement in the regularity of fibres.
Elektroprzędzenie jest techniką o niskich kosztach dla produkcji mikro i nano włókien. Zastosowanie PVA dla odkładania się włókien w wodnym roztworze posiada istotne zalety związane z uwalnianiem się leków i niską toksycznością polimeru. Niedoskonałości otrzymanych włókien w postaci zgrubień skłaniają do poszukiwania środków zaradczych. Badania wykazały, że małe ilości Triton X-100 zdyspergowanego w roztworze w ilości ok. 1% wpływają na zaokrąglenie zgrubień, podczas gdy przy 10% uzyskuje się pięciokrotną redukcję ilości defektów i ich zmniejszenie.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 4 (100); 39-43
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parasites community of Astronotus crassipinnis (Cichlidae), a fish from the Brazilian Amazon
Autorzy:
Santos, G.G.
Oliveira, M.S.B.
Neves, L.R.
Tavares-Dias, M.
Powiązania:
https://bibliotekanauki.pl/articles/972319.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
aggregation
parasites
Amazon
Astronotus crassipinnis
Cichlidae
Opis:
We provide the first study on the diversity and community of parasites in Astronotus crassipinnis from the lower Amazon River, in Brazil. Of 35 hosts examined, 100% were infected with one or more species of parasites, such as Gussevia asota, Gussevia astronoti, Gussevia rogersi, Posthodiplostomum sp., Contracaecum sp., Gorytocephalus sp. and Dolops longicauda. Gussevia asota, G. astronoti and G. rogersi were dominant, and, in total, 9788 parasites were collected. The richness of parasite species (4.9±0.7), Brillouin diversity (0.46±0.28) and evenness (0.29±0.17) were low. Parasites had aggregated dispersion, parasitism did not affect the host condition factor, and host size did not influence abundance, species richness and parasite diversity. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and low abundance, specifically the endoparasites, besides dominance of ectoparasites. The presence of endoparasites indicates that the diet of A. crassipinnis consists mostly of mollusks and microcrustaceans. This fish species is an intermediate host for Posthodiplostomum sp., Contracaecum sp. and Gorytocephalus sp., parasites found in larval stage. Finally, the behavior and availability of infective stages, which are intermediate hosts for endoparasites, were factors structuring the communities of endoparasites.
Źródło:
Annals of Parasitology; 2018, 64, 2; 121-128
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Definition of mooring plans for vessels at port terminals using physical models
Autorzy:
Bernardino, J.C.M
Pion, L.M.
Esferra, R.
de Oliveira Bezerra, R.
Powiązania:
https://bibliotekanauki.pl/articles/117411.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
port operations
mooring plan
port terminals
hydraulic works
Ponta da Madeira Port (PMP)
physical scale modelling
ship's mooring
mooring lines
Opis:
Physical scale models have a large range of application in studies of hydraulic works. In port engineering, they can be used to optimize the general layout of terminals, evaluation of protection structures, simulation of vessel maneuvers and investigation of mooring plans for vessels, among several subjects. Once physical modeling allows a high accuracy in the waves and currents representation as well as their interaction with the bottom and the vessels, the studies of mooring systems in coastal and estuarine ports based on physical modeling tests provide greater reliability in comparison with those grounded on distinct types of models. To highlight the importance of this kind of application, this article presents the case study of the Ponta da Madeira Port (PMP), located in the State of Maranhao, Brazil, developed with the support of the 1:170 scale reduced physical model conceived and calibrated for this area. This study analyzed several alternatives to improve the availability of the northern berth of the Pier III of PMP, including new mooring strategies and the construction of a new improvement structure. The results, which concerned on preliminary tests of the mooring lines tensions, evidenced structural intervention could substantially reduce the risk of mooring lines break, indicating that further investigations concerning different layouts for the improvement structure are promising in order to provide an increase of this berth availability.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2019, 13, 1; 107-114
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Relationship Between the Levels of Stress and the Age and Years of Service of Military Firefighters From the Fire Rescue Corps of the Metropolitan Area of the State of Sao Paulo
Autorzy:
de Oliveira, R. S.
de Barros Neto, T. L.
da Silva, A. A.
Grandi, J. L.
Menezes, I. B. S.
Powiązania:
https://bibliotekanauki.pl/articles/89950.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
burnout
professional
age effect
work hours
firefighters
Opis:
Purpose. To verify the relationship between stress indicators and the age and years of service of military firefighters from the fire rescue corps of the metropolitan area of the state of Sao Paulo. Methods. Forty military firefighters with the mean age of 37.9 ± 5.4 years, from the 1st, 2nd and 8th fire brigades of the metropolitan area of Sao Paulo participated in this study. All underwent clinical, physical and psychological evaluations to verify the relationship between the age and years of service with the variables of levels of stress (tension, depression, anger, vigor, fatigue, confusion and total stress) on workdays and on days off. Results. On workdays, the mean scores for tension, depression, fatigue and stress were overall higher compared to those on days off. The older the firefighter, the higher the levels of stress, depression, anger and total stress. The more years of service, the greater the depression and anger. Conclusions. The levels of stress were high on workdays. Chronological age and years of service influenced the increase in the scores of stress.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 4; 579-586
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of dosimetric peaks of MgB4O7:Dy (40% Tefl on) versus LiF:Mg,Ti TL detectors
Autorzy:
Paluch-Ferszt, M.
Kozłowska, B.
Oliveira de Souza, S.
Freire de Souza, L.
Nascimento Souza, D.
Powiązania:
https://bibliotekanauki.pl/articles/148068.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
thermoluminescent detectors
MgB4O7:Dy
LiF:Mg,Ti
Opis:
Magnesium tetraborate doped with dysprosium (MgB4O7:Dy) is known as a good thermoluminophor for personal dosimetry of gamma ray and X-ray radiation because of its high sensitivity and close tissue equivalence. This material can be produced by different routes. The sintered pastilles of magnesium tetraborate mixed with Tefl on (40%) used in this work were manufactured at the Federal University of Sergipe, Department of Physics by the solid-state synthesis. Magnesium tetraborate was already used for high-dose dosimetry, exhibiting linearity for a wide range of doses. In this work, the authors examined its main characteristics prior to potential use of detectors in everyday dosimetry, comparing this material to a widely used LiF:Mg,Ti phosphor. The following tests infl uencing dosimetric peaks of MgB4O7:Dy were presented: (1) the shape of the glow curves, (2) annealing conditions and post-irradiation annealing and its infl uence for background of the detectors, (3) the choice of the heating rates at the read-out and (4) the threshold dose, that is, the lowest possible dose to be measured. Simil ar tests were performed with LiF:Mg,Ti detectors, produced and widely used in Poland. The results were compared and discussed.
Źródło:
Nukleonika; 2016, 61, 1; 49-52
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness of nanoatrazine in post-emergent control of the tolerant weed Digitaria insularis
Autorzy:
Sousa, B.T.
Pereira, A.E.S.
Fraceto, L.F.
De Oliveira, H.C.
Dalazen, G.
Powiązania:
https://bibliotekanauki.pl/articles/2082785.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
atrazine
chemical control
nanoherbicide
nanotechnology
sourgrass
tolerant
weed control
Opis:
Digitaria insularis (sourgrass) is a monocotyledon weed of difficult control and high in- vasive behavior. Atrazine is widely applied in the Americas to control weeds in maize cul- ture, but its efficiency against D. insularis is limited. The incorporation of atrazine into poly(epsilon-caprolactone) nanocapsules increased the herbicidal activity against suscep- tible weeds; however, the potential of this nanoformulation to control atrazine-tolerant weeds including D. insularis has not yet been tested. Here, we evaluated the post-emergent herbicidal activity of nanoatrazine against D. insularis plants during initial developmental stages. The study was carried out in a greenhouse, using pots filled with clay soil. Plants with two or four expanded leaves were treated with conventional or nanoencapsulated at- razine at 50 or 100% of the recommended dosage (1,000 or 2,000 g ∙ ha −1 ), followed by the evaluation of physiological, growth, and control parameters of the plants. Compared with conventional herbicide, both dosages of nanoatrazine induced greater and faster inhibition of D. insularis photosystem II activity at both developmental stages. Atrazine nanoencap- sulation also improved the control of D. insularis plants, especially in the stage with two expanded leaves. In addition, nanoatrazine led to higher decreases of dry weight of four- leaved plants than atrazine. The use of the half-dosage of nanoatrazine was equally or more efficient in affecting most of the evaluated parameters than the conventional formulation at full dosage. Overall, these results suggest that the nanoencapsulation of atrazine potenti- ated its post-emergent herbicidal activity against D. insularis plants at initial developmental stages, favoring the control of this atrazine-tolerant weed.
Źródło:
Journal of Plant Protection Research; 2020, 60, 2; 185-192
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Triassic eucynodont Candelariodon barberenai revisited and the early diversity of stem prozostrodontians
Autorzy:
MARTINELLI, AGUSTÍN G.
BENTO SOARES, MARINA
DE OLIVEIRA, TÉO VEIGA
RODRIGUES, PABLO G.
SCHULTZ, CESAR L.
Powiązania:
https://bibliotekanauki.pl/articles/945630.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
cynodontia
probainognathia
prozostrodontia
dinodontosaurus assemblage zone
south america
brazi
Opis:
The dental anatomy of Candelariodon barberenai from the Dino donto saurus Assemblage Zone (Pinheiros-Chiniquá Sequence, Santa Maria Supersequence, late Ladinian–early Carnian) of south Brazil, is redescribed. Candelariodon was originally classified as Eucynodontia incertae sedis and our analysis recovered this taxon deeply nested within Probainognathia, as the sister taxon of Potheriodon plus Prozostrodontia. The lower postcanine dentition of Candelariodon has several apomorphies shared with Prozostrodon, Santacruzgnathus, Brasilodon/Brasilitherium, and some basal mammaliaforms (Morganucodon, Megazostrodon), such as a lingual cingulum with discrete cusps e and g and two distinct morphologies in the tooth row. The reinterpretation of Candelariodon as a probainognatian cynodont more derived than Probainognathus and the rich Brazilian fossil record document an important adaptive radiation of non-mammaliaform prozostrodontians and closely related forms prior to the origin of the mammaliaform clade.
Źródło:
Acta Palaeontologica Polonica; 2017, 62, 3; 527-542
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation of grounding grids parameter at arbitrary geometry
Autorzy:
Silva, C. L. B.
Pires, T. G.
Calixto, W. P.
Oliveira, D. N.
Souza, L. A. P.
Filho, A. M. S.
Powiązania:
https://bibliotekanauki.pl/articles/136173.pdf
Data publikacji:
2017
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
grounding grids parameters
Heppe
soil stratified in two layers
Opis:
This paper deals with the computation of ground resistance, surface voltage, touch voltage and step voltage, to mesh with horizontal wires arranged in different angles. The computer program implemented used in the mathematical modeling is based on the method proposed by Heppe, which allows obtaining the grounding parameters for homogeneous soil and soil stratified in two layers. The results obtained with the proposed method will be compared with other methods in literature. Also will be presented the results of a grounding grid using wires at various angles.
Źródło:
Transactions on Environment and Electrical Engineering; 2017, 2, 2; 11-17
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Facies architecture of the fluvial Missão Velha Formation (Late Jurassic-Early Cretaceous), Araripe Basin, Northeast Brazil : paleogeographic and tectonic implications
Autorzy:
Fambrini, G. L.
Neumann, V. H. M. L.
Menezes-Filho, J. A. B
da Silva-Filho, W. F.
de Oliveira, É. V.
Powiązania:
https://bibliotekanauki.pl/articles/139001.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Araripe Basin
Missão Velha Formation
fluvial facies
architectural element
rift basins
basen Araripe
Missão Velha
facje rzeczne
element architektoniczny
rów tektoniczny
Opis:
Sedimentological analysis of the Missão Velha Formation (Araripe Basin, northeast Brazil) is the aim of this paper through detailed facies analysis, architectural elements, depositional systems and paleocurrent data. The main facies recognized were: (i) coarse-grained conglomeratic sandstones, locally pebbly conglomerates, with abundant silicified fossil trunks and several large-to-medium trough cross-stratifications and predominantly lenticular geometry; (ii) lenticular coarse-to-medium sandstones with some granules, abundant silicified fossil wood, and large-to-medium trough cross-stratifications, cut-and fill features and mud drapes on the foresets of cross-strata, (iii) poorly sorted medium-grained sandstones with sparse pebbles and with horizontal stratification, (iv) fine to very fine silty sandstones, laminated, interlayered with (v) decimetric muddy layers with horizontal lamination and climbing-ripple cross-lamination. Nine architectural elements were recognized: CH: Channels, GB: Gravel bars and bed forms, SB: Sand bars and bedforms, SB (p): sand bedform with planar cross-stratification, OF: Overbank flow, DA: Downstream-accretion macroforms, LS: Laminated sandsheet, LA: Lateral-accretion macroforms and FF: Floodplain fines. The lithofacies types and facies associations were interpreted as having been generated by alluvial systems characterized by (i) high energy perennial braided river systems and (ii) ephemeral river systems. Aeolian sand dunes and sand sheets generated by the reworking of braided alluvial deposits can also occur. The paleocurrent measurements show a main dispersion pattern to S, SE and SW, and another to NE/E. These features imply a paleodrainage flowing into the basins of the Recôncavo-Tucano-Jatobá.
Źródło:
Acta Geologica Polonica; 2017, 67, 4; 515-545
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 30

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