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Tytuł:
A eutherian mammal in the latest Cretaceous of Vitrolles, Southern France
Autorzy:
Tabuce, R
Vianey-Liaud, M.
Garcia, G.
Powiązania:
https://bibliotekanauki.pl/articles/22800.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
eutherian mammal
Eutheria
mammal
Cretaceous
Mammalia
Vitrolles
France
paleontology
Opis:
In Europe, the fossil record of the eutherian mammals is very scanty for the Late Cretaceous, as only two genera, documented by isolated teeth, are presently recorded in France and in Spain. Both genera, Labes and Lainodon, are considered to be representatives of the “zhelestids”, a paraphyletic unit regarded as being at the origin of Cenozoic ungulates within the Ungulatomorpha clade. We here describe Valentinella vitrollense gen. et sp. nov. from Vitrolles la Plaine (Maastrichtian, southern France). This species, represented by fragmentary remains of lower and upper dentitions, is tentatively assigned to the “zhelestids” according to the hypoconulid−entoconid twinning and the antero−posteriorly short trigonid on m1–3. The occlusal surfaces are obliterated by dental attrition, but Valentinella could be an evolved “zhelestid”, more derived than Labes and Lainodon by its fully compressed trigonid. Valentinella is similar to Gallolestes by other derived characters such as a crushing specialization of the teeth, associated with a probably molariform p4 (or dp4) and slightly reduced m3. The enamel microstructure, showing a radial prismatic pattern combined with a reduced interprismatic matrix, in which cristallites are oriented at about 45° to the prisms axes, appears compatible with the ancestral morphotype for all ungulates; although no synapomorphy can be proposed for the ungulatomorphs.
Źródło:
Acta Palaeontologica Polonica; 2004, 49, 3
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Earliest laurasian sauropod eggshells
Autorzy:
Garcia, G
Marivaux, L.
Pelissie, T.
Vianey-Liaud, M.
Powiązania:
https://bibliotekanauki.pl/articles/22561.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
megaloolithid egg shell
Middle Jurassic
Bajocian
Quercy area
France
Sauropoda
fossil egg
paleontology
Opis:
Megaloolithid eggshells, known from many Cretaceous deposits since 19th century, are now recognized as remnants of sauropod dinosaurs. Our paper reports the discovery of megaloolithid egg remains from the Middle Jurassic (Bajocian) of the Quercy area (southwestern France). The new Jurassic ootaxon differs from related Cretaceous oospecies in having unusually thin shells. Even Megaloolithus aureliensis, the thinnest Cretaceous megaloolithid from France is three times thicker than the Jurassic eggshells. The cladistic analysis of ootaxa reveals a peculiar point in contradiction with the phylogenetic results based on skeletal remains: the Megaloolithidae belonged to sauropod dinosaurs, which appear to be the sister group of the hadrosaur eggs (Spheroolithidae oofamilly). This result could indicate a significant amount of homoplasy in the evolution of eggshell structures, depending strongly on the incubation environment (particularly for some characters as ornamentation, pore openings and pore canals), the reproductive physiology and the oviduct function. The Bajocian eggshells might represent the earliest offshoot of the Megaloolithidae oofamily and represent the earliest sauropod eggshell record known from the deposits of Laurasia supercontinent.
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 1
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Secondary electron interactions in materials with environmental and radiological interest
Autorzy:
García, G.
Blanco, F.
de Pablos, J.
Pérez, J.
Williart, A.
Powiązania:
https://bibliotekanauki.pl/articles/148529.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron scattering
energy deposition
Opis:
Important environmental and radiological applications require energy deposition models including the interactions between the secondary electrons and the atoms or molecules of the medium. In this work we propose a method to obtain reliable cross-section data to be used in these models by combining total and ionisation cross-section measurements with simple calculations of the differential and integral elastic cross sections. The energy loss spectra obtained in this experiment have been also used to derive the stopping power of the considered materials for electrons. Some examples of results for atomic (Xe) and molecular (CF4) targets are presented and discussed in this paper.
Źródło:
Nukleonika; 2003, 48, 2; 103-107
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular identification of Buxtonella sulcata from associated-diarrhea in water buffaloes (Bubalus bubalis) in the Philippines
Autorzy:
Dianso, J.A.
Garcia, G.G.
Belotindos, L.P.
Mingala, C.N.
Powiązania:
https://bibliotekanauki.pl/articles/5920.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Parazytologiczne
Źródło:
Annals of Parasitology; 2018, 64, 2
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using visual and force information in robot-robot cooperation to build metallic structures
Autorzy:
Pomares, J.
Gil, P.
Corrales, J. A.
Garcia, G. J.
Puente, S. T.
Torres, F.
Powiązania:
https://bibliotekanauki.pl/articles/384655.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Opis:
In this paper, a cooperative robot-robot approach to construct metallic structures is presented. In order to develop this task, a visual-force control system is proposed. The visual information is composed of an eye-in-hand camera, and a time of flight 3D camera. Both robots are equipped by a force sensor at the end-effector. In order to allow a human cooperate with both robots, an inertial motion capture system and an indoor localization system are em ployed. This multisensorial approach allows the robots to cooperatively construct the metallic structure in a flexible way and sharing the workspace with a human operator.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2009, 3, 3; 96-101
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enterprise logistics, indicators and physical distribution manager
Autorzy:
Hernández, J. R.
García, M. G.
Hernández, G. G.
Powiązania:
https://bibliotekanauki.pl/articles/409334.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
enterprise logistics
indicators
logistics models
physical distribution
Opis:
Four models were created to study enterprise logistics. From the first one of them, the Logistic Model Based on Positions (LoMoBaP), one of its forty-four charges, the Physical Distribution Manager will be taken, and indicators will be generated to measure its performance, following, the third one of the models, the Logistic Model Based on Indicators of Positions (LoMoBaIPo). The objective of this work is to show how indicators of management can be used in enterprise logistics, following the LoMoBaIPo to apply to the Physical Distribution Manager of the LoMoBaP. To obtain this objective it will be followed the Integrated-Adaptable Methodology for the development of Decision Support System [IAMDSS], which for their flexibility is very useful in other works of investigation, that not necessarily generate a Decision Support System (DSS). As result a set of tables are obtained, that allows to evaluate the Physical distribution Manager across indicators.
Źródło:
Research in Logistics & Production; 2013, 3, 1; 5-20
2083-4942
2083-4950
Pojawia się w:
Research in Logistics & Production
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a methodology for improving the tribological properties in die processing using laser surface texturing
Metoda polepszenia własności tribologicznych narzędzi do wykrawania przez zastosowanie laserowej obróbki powierzchni
Autorzy:
García, G. T. G.
Garza, M. T. V.
Garza, A. Q.
Zuazua, D. V.
Cortés, D. M.
Tellez, A. M.
Zamarrón, R. B.
Powiązania:
https://bibliotekanauki.pl/articles/971354.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
laser surface texturing
laser ablation
microcavities
lubrication
friction
die wear
deep drawing tool
teksturowanie laserowe
ablacja laserowa
mikrowgłębienia
smarowanie
tarcie
zużycie narzędzi
narzędzia do ciągnięcia
Opis:
The purposes of this investigation were to measure the positive effects in the lubrication through the application of micro textures made by laser (Laser Surface Texturing). Different types of micro textured patterns were studied, which vary in the quantity of micro cavities, micro cavity diameters, depths of micro cavities, and surface density attacked by micro cavities. It was found that, compared with plain steel surfaces, laser texturing significantly reduces friction and wear.
Propozycją niniejszej pracy jest zbadanie pozytywnego efektu smarowania poprzez wykonanie za pomocą obróbki laserowej mikrowgłębień na powierzchniach kontaktowych. Przestudiowano różne typy mikrowgłębień i różne wzory tekstury, liczbę mikrowgłębień oraz ich wymiary, jak również ich dystrybucję na powierzchni. Efektem tej obróbki było zredukowanie tarcia i zużycia w porównaniu z płaskimi powierzchniami stali.
Źródło:
Tribologia; 2014, 3; 47-58
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quality management and customer satisfaction in a tourist destination, a structural equation analysis
Zarządzanie jakością i satysfakcja klienta w miejscu przeznaczenia turystycznego, analiza równoważenia strukturalnego
Autorzy:
Perez, C. R.
Garcia, V. G.
Sanchez, R. A.
Martinez, V. R.
Powiązania:
https://bibliotekanauki.pl/articles/405510.pdf
Data publikacji:
2017
Wydawca:
Politechnika Częstochowska
Tematy:
quality management
customer satisfaction
tourist destination
tourism
structural equation analysis
zarządzanie jakością
zadowolenie klienta
destynacja turystyczna
turystyka
analiza równania strukturalnego
Opis:
The paper is based on the premise that customers aspire to achieve maximum satisfaction of the products or services they buy so that knowledge of customer satisfaction enables an organization organized according to provide quality services assuming that levels higher quality leads to higher levels of customer satisfaction. Its empirical research was carried out in the tourist destination Holguín, northeastern Cuba, including more than 2,000 tourists and 70 tourism service providers, and was designed to provide information on the relationship between the level of tourist satisfaction and the variables of quality assurance in the destination. By means of the compilation and analysis of the obtained data a model of structural equations was constructed to visualize the nature of the relations that they were intended to demonstrate. The obtained results indicate that there are relations between the variables that assure the quality and the satisfaction of the customer leaving identified the possibilities of improvement.
Artykuł opiera się na założeniu, że klienci dążą do osiągnięcia maksymalnej satysfakcji z kupowanych produktów lub usług, dzięki czemu wiedza o zadowoleniu klienta pozwala zorganizować organizację zgodnie z dostarczaniem wysokiej jakości usług, zakładając, że wyższa jakość prowadzi do wyższego zadowolenia klienta. Niniejsze badanie empiryczne przeprowadzono w miejscowości turystycznej Holguín w północno-wschodniej Kubie, wzięło w nich udział ponad 2000 turystów i 70 usługodawców turystycznych, a jego celem było dostarczenie informacji na temat związku między poziomem zadowolenia turystów a poziomem jakości świadczonych usług za pomocą kompilacji i analizy uzyskanych danych skonstruowano model równań strukturalnych, celem zwizualizowania charakteru relacji, które zamierzano zademonstrować. Uzyskane wyniki wskazują, że istnieją powiązania między zmiennymi, które zapewniają jakość i satysfakcję klienta, pozostawiając zidentyfikowane możliwości poprawy.
Źródło:
Polish Journal of Management Studies; 2017, 16, 1; 175-186
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stable or not stable? Recognizing surge based on the pressure signal
Autorzy:
Garcia, D.
Liśkiewicz, G.
Powiązania:
https://bibliotekanauki.pl/articles/175253.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
singular spectrum analysis
nonlinear dynamics
statistical pattern recognition
compressor
surge
Opis:
The surge protection may be worth millions of dollars. This is typical price of a centrifugal compressor repair combined with additional cost of nonfunctionality of an industry employing it. This threat is normally secured by application of an antisurge systems. Typically they are activated at predefined working conditions when compressor mass flow rate approaches region affected by the surge. As a result those systems are vastly limiting its operational range usually by a desirable region where compressor attains large pressure ratio. Therefore, a modern antisurge systems are aiming at diminishing this tradeoff by reacting to the real pressure signal gathered at high frequency. This paper presents one of those methods employing singular spectrum analysis. This algorithm has not been widely used for this application, while it was shown herein that it may bring clear distinction between stable and nonstable working condition, even at presurge conditions. Hence in further perspective it may bring anti-surge protection quality, that was not met with another methods.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 133; 55-68
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet-based Entropy Measure for Rate-Distortion Optimization in Image Coding
Autorzy:
Garcia-Alvarez, J.
Führ, H.
Castellanos-Dominguez, G.
Powiązania:
https://bibliotekanauki.pl/articles/226142.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
entropy
wavelet transform
information measure
rate distortion
Opis:
A novel method for calculation of the entropy measure in wavelet space is proposed. This perceived-based entropy measure uses a Second Order Model entropy estimator, in which the occurrence of neighbors is considered in formulation. It has the intention to allow the implementation of a more suitable measure in coding processes and a relationship between the metric and the description of perceptual features. This method is used for the Rate-Distortion optimization in order to improve the bit-allocation coding algorithm, demonstrating that the wavelet-based entropy estimates a truncation step close to the target rate. The hypothesis is founded in the effect of distortion on the coefficient allocation. Because entropy measure is a close approximation of the conditional probability of image in multiresolution space, it provides an adequate representation for the information of a Detail feature. A definition of Detail-based homogeneity variance criteria is used for the information quantity - wavelet representation space, in order to find the image that fits a given Quality Level criteria. Experimental results are obtained for artificial and natural databases.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 1; 25-31
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On roughness measurement by angular speckle correlation
Autorzy:
Salazar, F.
Belenguer, T.
García, J.
Ramos, G.
Powiązania:
https://bibliotekanauki.pl/articles/220643.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
roughness
speckle
non-destructive testing
Opis:
In this work, the influence of both characteristics of the lens and misalignment of the incident beams on roughness measurement is presented. To investigate how the focal length and diameter affect the degree of correlation between the speckle patterns, a set of experiments with different lenses is performed. On the other hand, the roughness when the beams separated by an amount are non-coincident at the same point on the sample is measured. To conclude the study, the uncertainty of the method is calculated.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 373-380
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new leanchoiliid megacheiran arthropod from the lower Cambrian Emu Bay Shale, South Australia
Autorzy:
Edgecombe, G.D.
Garcia-Bellido, D.C.
Paterson, J.R.
Powiązania:
https://bibliotekanauki.pl/articles/21269.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new arthropod
arthropod
leanchoiliid megacheiran arthropod
Lower Cambrian
Cambrian
South Australia
paleontology
Arthropoda
Megacheira
Leanchoiliidae
Oestokerkus
Leanchoilia
Alalcomenaeus
midgut gland
phylogenesis
Opis:
The Leanchoiliidae is well−known from abundant material of Leanchoilia, from the Burgess Shale and Chengjiang Konservat−Lagerstätten. The first Australian member of the group is Oestokerkus megacholix gen. et sp. nov., described from the Emu Bay Shale (Cambrian Series 2, Stage 4), at Buck Quarry, Kangaroo Island, South Australia, and is intermediate in age between the well known leanchoiliid species from the Burgess Shale and Chengjiang. Phylogenetic analysis of “short great appendage” arthropods (Megacheira) in the context of the chelicerate stem group resolves the Australian species as sister to Burgess Shale, Utah, and Chengjiang Leanchoilia species, but most readily distinguished from Leanchoilia and Alalcomenaeus by a different telson shape, interpreted as being forked, widening distally, and with a few dorsally curved spines at the posterior angle. Leanchoiliid interrelationships are stable to alternative character weights, and Megacheira corresponds to a clade in most analyses.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on centrifugation for improving freshwater invertebrate sample conservation
Autorzy:
Valdecasas, Antonio G.
García-Jiménez, Ricardo
Marín F.-Campoamor, Mercedes
Powiązania:
https://bibliotekanauki.pl/articles/1386435.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
live sorting
sampling trips
optimal sample conservation
benthos
streams
sortowanie przeżyciowe
wyprawy badawcze
optymalna ochrona próbek
bentos
strumienie
Opis:
Sorting of freshwater invertebrate samples is best done while the animals are still alive. However, sorting in the field generally means less overall sampling can be done in the allotted time. Placing samples under cold conditions has been the traditional way to extend the life of the organisms contained within them. In this work, we evaluated whether the addition of a centrifugation step extends the survival time of organisms post-sampling, thus providing more time for sorting. Three salad spinners were tested for their capacity to extract water from samples. Additional observations were made on the compaction of samples due to excessive centrifugation. We conclude that adding a short centrifugation step of 30 seconds prolongs the life of several freshwater invertebrate taxa, including Hydrachnidia, Nematoda and Ostracoda. Furthermore, when fixation of samples in the field is necessary, centrifugation reduces the amount of fixative to be added to the samples to reach a certain concentration. Fixed samples can also be centrifuged, which may be particularly relevant when sampling abroad as inflam-mable liquids are often prohibited on planes. In our experience, centrifuging fixed samples does not compromise the fixed organisms, or their genetic material.
Sortowanie prób bezkręgowców słodkowodnych najlepiej wykonywać przeżyciowo, jednak sortowanie w terenie prowadzi na ogół do ograniczenia liczby wybieranych taksonów w wy-znaczonym czasie. Umieszczanie próbek w niskich temperaturach jest tradycyjnym sposobem przedłużania życia zawartych w nich organizmów. W tej pracy oceniliśmy, czy dodanie etapu wirowania wydłuża czas przeżycia organizmów po pobraniu próbek, zapewniając tym samym więcej czasu na sortowanie. Trzy odsączarki do warzyw przetestowano pod kątem ich zdolności do ekstrakcji wody z próbek. Dodatkowe obserwacje dotyczyły zagęszczenia próbek w wyniku nadmiernego wirowania. Doszliśmy do wniosku, że dodanie krótkiego, 30-sekundowego etapu wirowania przedłuża życie kilku taksonów bezkręgowców słodko-wodnych, w tym Hydrachnidia, Nematoda i Ostracoda. Ponadto, gdy konieczne jest utrwalenie próbek w terenie, wirowanie zmniejsza ilość środka utrwalającego dodawanego do próbek, aby osiągnąć określone stężenie. Utrwalone próbki można również odwirować, co może być szczególnie istotne w przypadku pobierania próbek za granicą, ponieważ płyny łatwopalne są często zabronione w samolotach. Z naszego doświadczenia wynika, że wirowanie utrwalonych próbek nie zagraża utrwalonym organizmom ani ich materiałowi genetycznemu.
Źródło:
Acta Biologica; 2020, 27; 21-29
2450-8330
2353-3013
Pojawia się w:
Acta Biologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The OAE1a in Cuchía (Early Aptian, Spain): C and O geochemistry and global correlation
Autorzy:
García-Mondéjar, J.
Fernández-Mendiola, P. A.
Owen, H. G.
Powiązania:
https://bibliotekanauki.pl/articles/139445.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cretaceous
Aptian
Basque-Cantabrian Basin
C-O isotopes
TOC
kreda
apt
izotopy
Opis:
C-isotopes, TOC and O geochemical data from the lower Aptian Cuchía section in the western Basque-Cantabrian basin (BCB) allow an accurate delimitation of the OAE1a-equivalent and its geochemical Menegatti´s segments, a detailed δ13Ccarb correlation with regional and interregional sections, and a high-resolution construction of TOC and bulk-rock δ18Ocarb curves and their interpretation. The δ13Ccarb values range from -2‰ and +4‰ (VPDB). They agree with previous data from the eastern BCB sections (Aralar) confirming the ammonite age of the OAE1a in the Basque-Cantabrian basin: Deshayesites forbesi, Deshayesites deshayesi, and Deshayesites deshayesi-Dufrenoyia furcata transition Zones. Interregional δ13Ccarb correlation with pelagic (Cismon, Italy, and Mid-Pacific Mountains, DSDP Site 463) and neritic (Roquefort-La Bédoule, France) core sections, reveals a common profile of a wide negative excursion characteristic of the OAE1a. It consists of a double trough separated by a flat relative maximum, with two negative spikes in the upper trough of neritic sections. TOC absolute values range from 0.12% to 1.37%. Segments of the TOC curve with persistent low values closely correspond with descending segments of the δ13Ccarb curve, and are attributed to lesser organic productivity in the BCB. Detailed bulk-rock δ18Ocarb data (-5.71‰ to -1.05 ‰ PDB) and variation curve show two main positive O-isotope shifts and three minor positive inflections, within a general negative trend characteristic of the OAE1a. The two major positive shifts correspond to both shallowing upwards sequences and the lowermost can be related to a eustatic sea level fall. Independent interregional correlation of the O-isotope shifts with C-isotopes supports their interpretation as punctuating colder events within a general warming trend.
Źródło:
Acta Geologica Polonica; 2015, 65, 4; 525-543
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of probability density functions in modeling sample distribution of surface electromyographic (sEMG) signals
Autorzy:
Rosa, I. G.
Garcia, M. A. C.
Souza, M. N.
Powiązania:
https://bibliotekanauki.pl/articles/230062.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electromyography
EMG
surface EMG
sEMG
EMG onset detection
Opis:
The surface electromyography signal (sEMG) has been typically modeled as a Gaussian random process. However, some authors have reported that the probability density functions (pdfs) associated with the sample distribution of sEMG signal exhibits a more peaked shape than one could expected for a Gaussian pdf. This work aimed to reinvestigate the profile of the sEMG pdfs during five different load levels of isometric contractions of biceps brachii muscle, and compared the adequacy of four different pdfs (Gaussian, Logistic, Cauchy, and Laplacian) in describing the sample distribution of such signal. Experimental pdfs were estimated for each subject and load condition. The comparison between experimental pdfs obtained from sEMG data of forty volunteers and four theoretical pdfs was performed by fitting these functions to its experimental counterpart, and using a mean absolute errors in the assessment of the best fit. On average, the Logistic pdf seemed to be the best one to describe the sample distribution of sEMG signal, although the probabilistic results, considering binomial trials, were significant for both Gaussian and Logistic pdfs.
Źródło:
Archives of Control Sciences; 2013, 23, 4; 381-393
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Naturalne oczyszczanie estuariów skażonych naturalnymi izotopami promieniotwórczymi pochodzenia antropogenicznego w Hiszpani
Natural restoration of Spanish estuary historically affected by anthropogenic inputs of natural radionuclides
Autorzy:
Villa, M.
Absi, A.
Moreno, H.
Garcia-Tenorio, R.
Manjon, G.
Powiązania:
https://bibliotekanauki.pl/articles/340292.pdf
Data publikacji:
2004
Wydawca:
Główny Instytut Górnictwa
Tematy:
estuarium Odiel
ochrona środowiska w Hiszpanii
izotopy naturalne
Odiel estuary
environmental protection in Spain
natural radioisotope
Źródło:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa; 2004, 1; 36-37
1643-7608
Pojawia się w:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Hamiltonian approach to fault isolation in a planar vertical take-off and landing aircraft model
Autorzy:
Rodriguez-Alfaro, L. H.
Alcorta-Garcia, E.
Lara, D.
Romero, G.
Powiązania:
https://bibliotekanauki.pl/articles/330664.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
Hamiltonian method
observer
fault diagnosis
nonlinear system
UAVs
metoda Hamiltonowska
obserwator
diagnoza uszkodzeń
układ nieliniowy
Opis:
The problem of fault detection and isolation in a class of nonlinear systems having a Hamiltonian representation is considered. In particular, a model of a planar vertical take-off and landing aircraft with sensor and actuator faults is studied. A Hamiltonian representation is derived from an Euler–Lagrange representation of the system model considered. In this form, nonlinear decoupling is applied in order to obtain subsystems with (as much as possible) specific fault sensitivity properties. The resulting decoupled subsystem is represented as a Hamiltonian system and observer-based residual generators are designed. The results are presented through simulations to show the effectiveness of the proposed approach.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2015, 25, 1; 65-76
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vulnerabilidad socioeconomica y medioambiental: Valle de Cuautitlan-Texcoco, Estado de Mexico
Socioeconomic and environmental vulnerability: Valle de Cuautitlan-Texcoco, State of Mexico
Autorzy:
Hernandez, M.E.O.
Valdez Perez, M.E.
Alvarez Arteaga, G.
Gonzalez Guerrero, G.
Garcia Fajardo, B.
Powiązania:
https://bibliotekanauki.pl/articles/2077806.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Źródło:
Prace i Studia Geograficzne; 2019, 64, 2; 49-67
0208-4589
Pojawia się w:
Prace i Studia Geograficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic Analysis of the Graphite Flake Formation of Low Manganese and Sulfur Gray Cast Iron
Autorzy:
Reyes-Castellanos, G.
Cruz-Ramírez, A.
Colin-García, E.
Gutiérrez-Pérez, V. H.
Powiązania:
https://bibliotekanauki.pl/articles/2049436.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gray iron
inoculation
cell count
thermodynamic analysis
Opis:
Low manganese and sulfur gray irons were produced by adding inoculant base Fe-Si with small amounts of Al and Ca in the ladle. The effect of the cast thickness, inoculant amount and shakeout time of the green sand molds were studied on the graphite flake formation by microscopically techniques. A thermodynamic analysis was carried out for the cast iron produced with the FactSage 7.2 software. Stability phase diagrams were obtained for both gray cast irons to different manganese (0.1 to 0.9 wt.%) and sulfur (0.01 to 0.12 wt.%) amounts to 1150°C. It was shown that lower amounts of manganese and sulfur allow forming the 3Al2O3·2SiO2, Al2O3, and ZrO2 solid compounds. The thermodynamic results match with those obtained by SEM-EDS. It is possible to form MnS particles in the liquid phase when the solubility product (%Mn) × (%S) equals 0.042 and 0.039 for heats A and B, respectively.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 1; 249-258
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Nanofeatures Induced by High-Energy Heavy Ions Irradiation
Autorzy:
García-Bórquez, A.
Camacho-Olguín, C.
Herrera-Colín, L.
Rueda-Morales, G.
Kesternich, W.
Powiązania:
https://bibliotekanauki.pl/articles/2044682.pdf
Data publikacji:
2006-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
96.35.Gt
34.50.Dy
Opis:
During neutron, ions or electron irradiation of materials, the surface morphology can be microroughened in different forms. Using a tandem accelerator with high current capability, 3.66 MeV Ni and Al ions were implanted into Ni-22at%Si alloy at 650ºC and intoα-Al$\text{}_{2}$O$\text{}_{3}$ at 1000ºC, respectively. Scanning electron microscopy observation revealed surface nanofeatures induced by the irradiations. On the Ni--Si alloy, long parallel channels are formed having a periodicity near to 2μm and a mean depth of 30 nm (atomic force microscopy measurements). Onα-Al$\text{}_{2}$O$\text{}_{3}$ nanopyramides with around 50 nm basis length and similar height were detected on some grains forming periodic chains. We assume that preferential sputtering produced both induced surface features.
Źródło:
Acta Physica Polonica A; 2006, 109, 3; 347-351
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Youngest agamid lizards from Western Europe (Sierra de Quibas, Spain, late Early Pleistocene)
Autorzy:
Blain, H.-A.
Bailon, S.
Agusti, J.
Pinero-Garcia, P.
Lozano-Fernandez, I.
Sevilla, P.
Lopez-Garcia, J.M.
Sanchez, G.R.
Mancheno, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/21138.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Here we report a new Early Pleistocene record of agamid lizards (Agamidae indet.) from the Spanish locality of Quibas (ca. 1.3–1.0 Ma), which represents the latest evidence of the family in Western Europe. Up to now, the family Agamidae was considered to have disappeared in this region at 1.8 Ma. This new record implies the survival of agamid lizards for a large part of the Early Pleistocene in the southernmost Iberian Peninsula, probably because of favourable climatic and environmental conditions. Consequently, the formerly detected Pliocene / Pleistocene boundary is no longer recognisable in the evolution of the herpetological assemblages in Western Europe.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Short-term effects of spent coffee grounds on the physical properties of two Mediterranean agricultural soils
Autorzy:
Cervera-Mata, A.
Martin-Garcia, J.M.
Delgado, R.
Parraga, J.
Sanchez-Maranon, M.
Delgado, G.
Powiązania:
https://bibliotekanauki.pl/articles/2082515.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
organic amendment
soil aggregate stability
soil water retention
soil aggregate size
SEM images
Opis:
We investigated the short-term effects of spent coffee grounds on the physical properties of two Mediterranean agricultural soils (Calcisol and Luvisol). The in vitro assay was performed with two spent coffee grounds doses (60 and 240 Mg ha-1), two incubation times (30 and 60 days) and two modalities: with and without lettuce seedlings (Lactuca sativa var. longifolia). Spent coffee grounds addition increased water retention at -33 and -1500 kPa, and decreased bulk density and plant-available water content. With spent coffee grounds, the percentage of macroaggregates increased, the percentage of meso- and microaggregates decreased and the structural stability of all types of aggregates increased. The stereomicroscopy images showed that: the structural aggregates were rounded, the porosity increased by 316%, the structure was ordered into smaller aggregates, the incorporation of spent coffee grounds particles could occur in intraped cracks and spent coffee grounds particles could act as a binding agent. Scanning electron microscopy also showed that spent coffee grounds particles interacted with mineral particles and integrated into soil structure; moreover, fungal hyphae also developed on many spent coffee grounds particles. If spent coffee grounds effects are compared with those described in the literature for other organic amendments, the same trend was observed in most of the soil physical properties although with a different intensity, principally with regard to structural stability.
Źródło:
International Agrophysics; 2019, 33, 2; 205-216
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indirect torque observer-based sensor-less efficient control of bearingless switched reluctance motor using global sliding mode and square currents control method
Autorzy:
Rao, Pulivarthi Nageswara
Devarapalli, Ramesh
Marquez, Fausto Pedro Garcia
Kumar, G. V. Nagesh
Mohammadi-Ivatloo, Behnam
Powiązania:
https://bibliotekanauki.pl/articles/1409027.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bearingless
global sliding mode
efficient: maintenance
safety
torque ripple
Opis:
The Bearingless Switched Reluctance Motor (BSRM) is a new technology motor, which overcomes the problems of maintenances required associated with mechanical contacts and lubrication of rotor shaft effectively. In addition, it also improves the output power developed and rated speed. Hence, the BSRM can achieve high output power and super high speed with less size and cost. It has a considerable ripple in the net-torque due to its critical non-linearity and the salient pole structures of both stator and rotor poles. The resultant torque ripple, especially in these motors, causes the more vibrations and acoustic noises will affects the levitated rotor safety also. Practically at high-speed operations, the accurate measurement of the rotor position is complicated for conventional mechanical sensors. A new square currents control with global sliding mode control based sensorless torque observer is proposed to minimize the torque ripple and achieve a smooth, robust operation without using any mechanical sensors. The proposed controller is designed based on the error between the reference and measured torque values. The sliding mode torque observer measures the torque from the actual phase voltages, currents, and look-up tables. The simulation model has been modelled to validate the proposed methodology. From the simulation outputs, it is clear that the reduction of torque ripple by the proposed method shows improved than the conventional sliding mode controller. The overall system is more robust to the external disturbances, and it also gets efficient torque profile.
Źródło:
Archives of Control Sciences; 2021, 31, 1; 53-80
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 27

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