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1
Content available remote Influence of Tensile Stress on Woven Compression Bandage Structure and Porosity
EN
Woven compression bandage (CB) is one of the elastic textiles that exert pressure on muscles. With a defined tensile strength, it is possible to create the required compression on the given body parts. This work aims to investigate the relationship between woven fabric deformation, porosity, and tensile stress properties of three main types of woven CBs. All bandage samples are applied on human leg using two- and three-layer bandaging techniques. Bandage porosity is calculated for all frames at different weave angles using NIS software. Woven bandage construction parameters which are given by the preparation of warp and weft yarns, twist, count, and density along with woven fabric weave, type of weaving, and finishing process are the main factors that influence the bandage properties. Several methods considering thread distributions have been developed to determine the woven fabric's porosity during the tensile stress. Experimental results confirm that bandage porosity is directly proportional to the bandage extension and weave angle that ranges from 44° to 90°. The novelty of candidate study is to introduce practical remarks to the patient for optimizing the required bandage pressure by suitable extension or applied tension or weave angle for two- and three-layer bandaging systems.
PL
W artykule przedstawiono dwie realizacje filtru Gaussa 1D. Pierwsza oparta jest na bezpośredniej implementacji splotu, druga bazuje na filtrze ortogonalnym realizowanym za pomocą rotatorów Givensa. Obie realizacje został przeanalizowane pod kątem wrażliwości na kwantowanie współczynników dla 8-, 16- i 24-bitowych rejestrów. Wyznaczono i porównano błędy średniokwadratowe charakterystyki amplitudowej oraz błędy dla odpowiedzi systemu na pobudzenie losowym szumem i deltą Kroneckera.
EN
In the paper, two realizations of 1D Gauss filter are presented. The first realization is based on direct structure with convolution, in the second orthogonal filter with use Givens rotations is realized. Both systems are analyzed of sensitivity on coefficient quantization for 8-, 16- and 24- bits length of register. Also determined mean squared errors for amplitude characteristics, impulse responses and responses on noise excitation.
PL
Rozwój materiałów w oceanotechnice otwiera nowe możliwości w budowie jachtów. Poniższy artykuł porusza kwestie wplatania nowoczesnych lin typu HMPE (ang. high-modulus polyethylene) w konstrukcje takielunku jachtu, a dokładniej w część olinowania ruchomego. Dzięki specjalnej konstrukcji liny bez oplotu zbudowanej z 12 splotek utworzonej przez ich przeplatanie, możliwe jest konstruowanie drobnych elementów nośnych, takich jak miękkie oczka, zawiesia bezkońcowe i pojedyncze lub miękkie szekle zaledwie w kilka minut. Celem pracy jest sprawdzenie nośności poszczególnych technik plecenia w statycznej próbie rozciągania. Przebadano trzy grupy splotów, porównano ich wyniki pod względem wytrzymałościowym i statystycznym. Po analizie rezultatów wyznaczono najbardziej niezawodne techniki sporządzania węzłów i splotów na linie wyprodukowanej przez firmę Lancelin, model PURE DYNEEMA Racing Braid o średnicy 5 mm.
EN
The development of materials in ocean engineering opens new possibilities in the field of yachts construction. The following article discusses the issue of placing modern high-modulus polyethylene (HMPE) ropes in the construction of the rigging of the yacht, and more specifically in the part of running rigging. Thanks to the special no cover construction of the 12 strands rope, created by their interlacing, it is possible to construct small load-bearing elements such as loops, slings or soft shackles in just a few minutes. The purpose of my work is to check the carrying capacity of individual plaiting techniques in a static tensile test. Three groups of spliced elements were tested, their results were compared in terms of strength and statistics. After analyzing the results, the most reliable techniques for making knots and splices on a rope manufactured by Lancelin, the PURE DYNEEMA Racing Braid model with a diameter of 5 mm, were determined.
EN
In this paper, we investigate and study the existence of solutions for perturbed functional integral equations of convolution type using Darbo's fixed point theorem, which is associated with the measure of noncompactness in the space of Lebesgue integrable functions on R+. Finally, we offer an example to demonstrate that our abstract result is applicable.
EN
The influence of weave on woven fabric tear strength is analysed in this paper. Brierlay’s factor Fm, Milašius’ factor P and P’ and modification ofparameter P made by the authors (P’weft) were used in the investigations presented. Woven fabrics of 100 % viscose multifilament yarn manufactured from the same yarns and with the same density but with seven different weaves (plain weave, weft rib 2/2, warp rib 2/2, twill 2/2, twill 3/1, basket weave 2/2 and 4 healds sateen) were used for the investigations. It was stated that the well-known weave parameters of Brierley Fm and Milašius P and P’ cannot be used for the prediction of the tear strength of all kinds of weaves without any limitations. All parameters presented can be used for the strength prediction of a weave when they are divided into two groups – a rib-based group andtwill-based group. Prediction of the tear strength for rib-based weaves in the weft has to be carried out usingparameter P’weft , where the influence of parameters P1 and P is varied.
PL
W artykule omówiono wpływ splotu na wytrzymałość na rozdarcie tkanin. W przedstawionych badaniach wykorzystano współczynnik FmBrierlay’a, współczynnik P i P’ Milašius’a oraz modyfikację parametru P dokonaną przez autorów (P'weft). Do badań zostały wykorzystane tkaniny z przędzy wielowłókienkowej 100% wiskozowej, wytworzone z tej samej przędzy i o tej samej gęstości, ale różnymi splotami. Stwierdzono, że znane parametry splotu Brierley’a Fm i Milašius’a P i P' nie mogą być wykorzystywane bez ograniczeń do przewidywania siły rozrywania wszelkiego rodzaju splotów. Poszczególne parametry mogą być wykorzystane do prognozowania siły splotu w stosunku do konkretnych rodzajów splotów.
EN
This paper presents the experimental and numerical analysis of the potential of a braided fabric for flexor tendon repair. Numerical models of tubular braided fabrics were generated using a python script interface and imported into ABAQUS® while Flexor tendon models were represented as silicone rubber rods. Experimental tests and Finite Element Modelling (FEM) of the flexor tendon repair was undertaken by deploying two tendon ends from opposite sides of a tubular braided fabric. This was done such that the tendon ends meet at the midpoint within the fabric. The tendons were tightly held to emulate a realistic repaired tendon. A displacement driven uniaxial loading was induced on the tendon-fabric assembly sufficient to cause a 2mm gap between the tendon ends. Numerical analysis of the repair potential of a braided fabric in tendon repair was done by analyzing selected fabric parameters that were crucial in tendon repair applications. The results show that changing the parameters of the braided fabrics significantly affected the potential of the fabrics during tendon repair.
7
Content available remote Digital filters: hermitian, antihermitian, unitary and their applications
EN
The paper presents the relation between the three types of noncausal digital filters: unitary, Hermitian and antihermitian filters. A decomposition has been made of a causal filter into a Hermitian and unitary filter cascade, and the use of this decomposition to calculate the electric power quality of receivers has been highlighted. Reference has also been made to the analogy between the set of unitary filters and the unit circle in the Gaussian plane.
PL
W artykule podano związek między trzema typami nieprzyczynowych filtrów cyfrowych: filtrami unitarnymi, hermitowskimi i antyhermitowskimi. Dokonano też rozkładu filtru przyczynowego na kaskadę filtru hermitowskiego i unitarnego, oraz zwrócono uwagę na zastosowanie tego rozkładu do jakościowo-energetycznej oceny odbiorników energii elektrycznej. Nawiązano też do analogii zbioru filtrów unitarnych i okręgu jednostkowego na płaszczyźnie Gaussa.
EN
Drape is a very important utility parameter of fabrics, especially applied in clothing. It influences the aesthetic effect of clothing, in particular its fitting to the user’s body. Fabric draping is the result of interaction between gravitation and various fabric characteristics. In the work presented, cotton woven fabrics of different structure were measured in the range of their drapeability. The fabrics differed from each other in the range of their weave and linear density of weft yarn. Measurement of the fabrics was made by means of a fabric drape tester. Results of the measurement were analysed in the aspect of the relationships between the drape of the fabrics and their parameters, such as the kind of weft yarn, weave, weft density and stiffness. Results confirmed that for the group of fabrics investigated, their stiffness is the most significant property influencing the drapeability of fabrics. Additionally different weaves result in different values of the drape coefficient and shape factor.
PL
Układalność jest bardzo ważnym parametrem użytkowym tkanin, zwłaszcza stosowanych w odzieży. Wpływa ona na walory estetyczne odzieży, w szczególności jej dopasowanie do sylwetki użytkownika. Układalność tkanin jest efektem wzajemnego oddziaływania sztywności zginania i masy powierzchniowej. W artykule przedstawiono badania układalności tkanin o zróżnicowanej strukturze, wynikającej z zastosowania różnych splotów oraz masy liniowej przędzy wątkowej. Wyniki przeanalizowano pod kątem zależności pomiędzy układalnością tkanin, a ich parametrami strukturalnymi, takimi jak: masa powierzchniowa, splot, grubość i liczność wątku.
EN
In this research, thermal and water vapor resistance, components of thermal comfort of 65/35 and 33/67% polyester/ cotton (PES/CO) blend fabrics woven with 2/2 twill, matt twill, cellular and diced weaves, which are commonly used for clothing, were determined. The results indicate that both the fabric construction and the constituent fiber properties affect thermal comfort properties of clothing woven fabrics. Cellular weave, which is derivative of sateen weave and diced weave, which is compound weave, has the highest thermal resistance appropriating for cold climatic conditions. On the other hand, the 2/2 twill weave and matt twill weave, which is derivative of sateen weave, depicted the lowest water vapor thermal resistance, making it convenient for hot climatic conditions. Besides, fabrics woven with 65/35% PES/CO blend yarns have higher thermal resistance, so they are suitable for cold climatic conditions. Fabrics woven with 33/67% PES/CO blend yarns have lower water vapor resistance, so they are convenient for hot climatic conditions.
10
EN
In the literature analyzed there are no interdisciplinary researches that could combine both ethnographic and technological investigations of Lithuanian folk home textiles. Therefore, the goal of this article is to make a complex investigation of Lithuanian ethnographic home textiles analyzing its patterns, weaves, colour repeats and weave symmetry groups. 849 multipurpose ethnographic home textile fabrics (bedspreads, pillow-slips, slip-covers, towels, tablecloths, pieces of different purposes, curtains, bed sheets) from 5 Lithuanian museums were analyzed. In Lithuanian ethnographic home textiles six different types of patterns were distinguished, of which fancy, motley, checked and plane fabrics were the most popular. In the home textiles analyzed there were found 22 different types of weaves. Checked twill, plane and overshot four-harness weaves were the most popular. While analyzing symmetry groups of colour repeats and weaves according to classical principles of ornamentation, six symmetry groups were distinguished. Although patterns and weaves have the same symmetry groups, their distribution is different in both cases.
PL
W analizowanej literaturze nie stwierdzono interdyscyplinarnych badań, które łączyłyby aspekty etnograficzne i technologiczne dotyczące litewskich tekstyliów ludowych. Celem badań była kompleksowa analiza tych zagadnień. Badano wzory, kolory, sploty. Przebadano 849 próbek tkanin (bielizna pościelowa, ręczniki, obrusy, zasłony itp.) pochodzących z 5 litewskich muzeów. Stwierdzono istnienie 6 różnych typów wzorów najbardziej popularnych. Z domowych wyrobów tekstylnych wyróżniono 22 typy splotów. Najbardziej popularne sploty to sploty skośne, lniany, z górnym wątkiem oraz cztero–nicielnicowe.
EN
The paper presents a construction of Sylow 2-subgroups of symmetric and alternating groups, which bases contains only an involutions. Polynomial representation of Sylow 2-subgroups was used.
PL
W artykule przedstawiono konstrukcję takich 2-podgrup Sylowa grup symetrycznych i alternujących, których bazy zawierają wyłącznie inwolucje. Zastosowano reprezentację 2-podgrup Sylowa za pomocą zredukowanych wielomianów wielu zmiennych nad ciałem Z2.
EN
We define two new general integral operators for certain analytic functions in the unit disc U and give some sufficient conditions for these integral operators on some subclasses of analytic functions.
EN
In the present paper we define some classes of meromorphic functions with fixed argument of coefficients. Next we obtain coefficient estimates, distortion theorems, integral means inequalities, the radii of convexity and starlikeness and convolution properties for the defined class of functions.
14
Content available remote Effect of Weave Structure on Thermo-Physiological Properties of Cotton Fabrics
EN
This paper aims to investigate the relationship between fabric weave structure and its comfort properties. The two basic weave structures and four derivatives for each selected weave structure were studied. Comfort properties, porosity, air permeability and thermal resistance of all the fabric samples were determined. In our research the 1/1 plain weave structure showed the highest thermal resistance making it suitable for cold climatic conditions. The 2/2 matt weave depicted the lowest thermal resistance which makes it appropriate for hot climatic conditions.
EN
The aim of this study was to investigate the effect of knitting parameters on the moisture management and air permeability of the interlock fabrics. Samples were produced at two different knitting gauges, each with three different stitch lengths. It was found that the fabric mass per square metre increases by increasing machine gauge and decreasing the stitch length, whereas the fabric thickness and porosity increase at these settings. It was further concluded that the loosely knitted fabric samples with higher amount of entrapped air exhibit good air permeability but poor moisture management properties.
16
Content available remote Ultradźwiękowa metoda określania odległości
PL
Artykuł prezentuje innowacyjną metodę pomiaru czasu opóźnień fali ultradźwiękowej. Metody impulsowe stosowane w dotychczasowych badaniach charakteryzują się latencją, której to wady pozbawiona jest metoda splotu z sygnałem odwrotnym. Przedstawiona metoda pozwoliła uzyskać lepsze wyniki niż te uzyskane dotychczasowymi metodami. Opracowano i przetestowano algorytm pomiaru opóźnienia fali odbitej za pomocą układu mikroprocesorowego ARM CORTEX M4 sprzężonego z komputerem PC. Metoda wykorzystując sygnał z głowicy ultradźwiękowej umożliwiła precyzyjne wyznaczenie opóźnienia wywołanego czasem propagacji fali ultradźwiękowej w ośrodku. W celu weryfikacji skuteczności metody część układu pomiarowego zrealizowano w programie LabVIEW. Prezentowana metoda okazała się skuteczna, co potwierdzają zaprezentowane w pracy wyniki symulacji.
EN
This paper presents an innovative method for measuring the time delay of ultrasonic waves. Pulse methods used in the previous studies is characterized by latency, The method of inverse wave convolution, presented in the article is free from this disadvantages. The presented method allows to obtain better results than those obtained with previous methods. The algorithm of the delay measurement of reflected wave with the microprocessor ARM Cortex M4 coupled with a PC has been worked out and tested. This method use the signal from the ultrasonic probe to make precise determination of time delay caused by the propagation of the resort, possible. In order to verify the effectiveness of the method a part of the measuring system was implemented in LabVIEW. The presented method proved to be effective, as is confirmed in the presented simulation results.
17
Content available remote Some properties of generalized convolution of harmonic univalent functions
EN
The purpose of the present paper is to investigate some interesting properties on generalized convolutions of functions for the classes HP∗(α), HS(α) and HC(α). Further, an application of the convolution on certain integral operator are mentioned.
18
Content available remote Applications of convolution properties
EN
K. I. Noor (2007 Appl. Math. Comput. 188, 814–823) has defined the classes Qk(a, b, λ, γ) and Tk(a, b, λ, γ) of analytic functions by means of linear operator connected with incomplete beta function. In this paper, we have extended some of the results and have given other properties concerning these classes.
19
Content available remote A class of univalent functions involving a differentio-integral operator
EN
This paper focuses on a generalized linear operator Im which is a combination of both differential and integral operators. Involving this operator, a class Tsk(...) with respect to k-symmetric points is defined. Results based on coefficient inequalities and bounds for this class are obtained. Various integral representations and some consequent results for TS(...) class are also determined. Further, results on partial sums are discussed.
EN
It is shown [1] that even though the production of precast pre-tensioned concrete elements started more than 50 years ago, no one has ever succeeded in determining the real transmission length or in obtaining adequate measures to control it, due to the quality of the production. These arrears are confirmed by the study of existing standards. In general, it is assumed that the measurement of the magnitude of the slippage of strand at the end of hollow core prestressed slab is an indirect method of estimation and control of the value of the transmission length. One should mention that EN1168 and EN13369 that regulate requirements of designing and production of hollow-core slabs are applied as the method of control. Based on a particular bond-slip relation for strands, a nonlinear equation is developed for the transmission length and for the slippage of prestressed strand, taking into account such factors as the concrete strength at transfer, the degree of the initial prestress type and diameter of tendons. These equations have been used for the control of transmission length of the strands calculated by different methods available recently, including a code provision. Then they were compared to measured data, obtained in production control of the hollow-core slabs.
PL
Bazując na szczególnej relacji przyczepność – poślizg dla splotów, opracowano równania nieliniowe dla długości zakotwienia i dla poślizgu sprężonych splotów przy uwzględnieniu czynników: wytrzymałości betonu, efektywności początkowego sprężenia i rozmiaru splotu. Te równania zostały użyte do skontrolowania długości zakotwienia sprężonych splotów obliczonych za pomocą różnych metod dostępnych w ostatnim czasie, uwzględniając zalecenia normowe, które zostały porównane z wynikami pomiarów uzyskanych podczas kontroli procesu produkcyjnego płyt kanałowych.
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