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EN
Due to the fierce international competition in today’s clothing market, businesses have started to pay more attention to marketing activities. One of the most popular of these marketing activities is Instagram marketing. For this reason, the aim of this study was to identify the problems faced by clothing businesses that perform garment marketing on Instagram, to rank them in order of importance and to develop solutions to the most important problems. Within the scope of the research, firstly, the problems encountered by businesses while marketing clothing on Instagram were determined through data obtained from 14 businesses through a designed questionnaire. The problems identified are technical problems, cargo-related problems, difficulty in increasing the number of followers, and various other issues. Secondly, all the problems identified in the research were ranked by the Pythagoras Fuzzy AHP Method according to the degree of importance; increasing the number of followers, technical problems, lack of trust and others. In the last stage of the research, expert opinion from Instagram marketing experts of 14 businesses was used to develop solutions to the three most important problems previously identified. The solution suggestions developed are as follows: to increase the number of followers of businesses, to increase the number and variety of advertisements and to make advertising campaigns continuous; for technical problems - to share purchase links to customers, to keep the programs used constantly updated, to get professional support and to focus more on story ads instead of post ads; and for the problem of lack of trust - honesty, phenomenon support, product photo shoots within the business.
EN
The potential of Georgian natural Mordenite has been studied as a low-cost, eco-friendly adsorbent for the removal of lead (II) ions from aqueous solutions in various experimental environments. The natural and modified Mordenite structural characterization was carried out using XRD, SEM-EDS, XRF, methods. The following parameters were studied for adsorption: dependence of solution pH, adsorbent dose, and initial concentration of lead (II) ions. The results of the optimization study showed that a high dose of adsorbent and a low concentration of Pb (II) ion increase the sorption. The optimum pH was found to be 6-8. Sorption capacity increased along with pH. Langmuir and Freundlich isotherms were used to model the adsorption data. Correlation coefficient values (R2) were 0.975 and 0.922, respectively. Isotherm studies showed that the uptake equilibrium is best described by the Langmuir adsorption isotherm. The maximum sorption capacity was found to be 11.439 mg/g. The research results showed that natural Georgian Mordenite can be used to remove Pb (II) ions from aqueous solutions.
PL
Artykuł przedstawia przygotowany algorytm na bazie połączenia idei znanych metod numerycznych z metodami opartymi na idei roju. Algorytm został przygotowany z inspiracji polem walki podczas którego w równych odstępach żołnierze przeczesują siły wroga z różnymi prędkościami zależnie od posiadanego orężu a następnie ograniczają zakres pola bitwy. Zaproponowane rozwiązanie wywodzi się właśnie ze zbliżonych założeń. Głównym założeniem pracy było przedstawienie potencjalnego zysku z połączenia metod optymalizacji oraz porównanie metody mieszanej z metodami bazującymi na idei roju pod względem prędkości działania oraz skuteczności odnajdowania optimum globalnego.Algorytm został porównany z dwoma algorytmami metaheurystycznymi pod kątem dokładności odnalezionych rozwiązań oraz prędkości. Zgodnie z wynikami eksperymentów posiada wydajność podobną w porównaniu z innymi algorytmami oraz daje zadowalające efekty w wykorzystaniu.
EN
he article presents prepared algorithm based on the combination of the ideas of known numericalmethods with methods based on the idea of a swarm. The algorithm was prepared inspired by the battlefield,during which, at equal intervals, soldiers scour enemy forces at different speeds depending on the weapon theyhave, and then limit the scope of the battlefield. The proposed solution is based on similar assumptions. Themain assumption of the work was to present the potential profit from the combination of optimization methodsand to compare the mixed method with methods based on the idea of a swarm in terms of operating speed andthe effectiveness of finding the global optimum. The algorithm was compared with two metaheuristic algorithmsin terms of the accuracy of the solutions found and speed. According to the results of the experiments, it hasa similar performance compared to other algorithms and gives satisfactory results in use.
EN
Expanded polystyrene is widely used as a material for packaging, in modern construction as a heat and sound insulation layer, in thermal insulation systems for buildings, as well as tanks and pipelines. It is additionally used in foundry engineering for the production of models which are gasified during the production of castings from ferrous and non-ferrous alloys under the contact with liquid metal. The use of expanded polystyrene products is associated with waste generation, both in production and in consumption. About 40–50 kg/person of polystyrene waste is generated per year. The peculiarity of polymeric wastes is their resistance to aggressive environments. They do not rot and the destruction processes in natural conditions proceed rather slowly, with the formation of harmful substances that poison the environment. Therefore, the problem of the processing of waste from polymeric materials is of great importance, not only from the standpoint of environmental protection, but also due to the fact that in conditions of a shortage of polymer raw materials, this waste becomes a powerful raw material resource. This article describes the prospects for recycling expanded polystyrene wastes in foundry engineering. In this work, the properties of molding and core sands containing a combined binder, consisting of a solution of expanded polystyrene wastes in turpentine and clay were investigated, and their main characteristics (weight during stretching and crumbling) were determined. Molding and core mixtures, which contain only a binder in the form of a solution of expanded polystyrene in turpentine, have a crude strength of not more than 0.01 MPa. The introduction of a mixture of clay in the amount of 2–3% allows a crude strength of the mixture of up to 0.05 MPa to be obtained. After drying, the investigated mixtures containing a solution of expanded polystyrene wastes and clay have a tensile strength of up to 2.1 MPa. Mixtures into which a solution of polystyrene wastes and clay was introduced have an insignificant gas capacity and satisfactory gas permeability.
EN
The Lagrange-Sylvester formula is applied to the computation of the solutions of state equations of fractional continuous-time and discrete-time linear systems. The solutions are given as finite sums with their numbers of components equal to the degrees of the minimal characteristics polynomials of state matrices of the systems. Procedures for computations of the solutions are given and illustrated by numerical examples of continuous-time and discrete-time fractional linear systems.
6
Content available remote Warunki powstawania thaumasytu i metody im zapobiegania
PL
W pracy wykorzystano dwie metody powstawania thaumasytu: 1) poprzez poddanie zaczynu z portlandzkiego cementu wapiennego, z 30% dodatkiem kamienia wapiennego, na działanie 4% roztworu siarczanu magnezu przez 3 miesiące, w temperaturze 7°C, 2) w wyniku karbonatyzacji mieszaniny ettringitu z krzemianem sodu w temperaturze 7°C, a następnie zwiększenie pH na skutek dodatku wapna. Uzyskany skład fazowy próbek oznaczono rentgenograficznie i za pomocą spektroskopii w podczerwieni, a mikrostrukturę stosując elektronowy mikroskop skaningowy. Thaumasyt powstawał po 2 miesiącach przechowywania próbek zaczynu z portlandzkiego cementu wapiennego, w roztworze siarczanu magnezu. Można temu procesowi zapobiegać stosując dodatek związków chemicznych zmniejszających stężenie jonów wapniowych i siarczanowych. Potwierdzeniem skuteczności tych metod są wyniki badań mikrostruktury oraz wytrzymałości na ściskanie. Powstawanie thaumasytu tłumaczy się tworzeniem fazy przejściowej składającej się z żelu krzemionkowego zawierającego pozostałości ettringitu, który w większości uległ rozkładowi. Faza ta przechodzi w thaumasyt na skutek wzrostu pH, wywołanego dodatkiem wapna. Uzyskane wyniki są zgodne z pracą opublikowaną już w 2003 roku, w której stwierdzono powstawanie thaumasytu z fazy przejściowej, stanowiącej szczególny przypadek korozji siarczanowej zaczynu cementowego. W pracy opisano właściwości tej fazy. Thaumasyt początkowo nie powstawał w próbkach portlandzkiego cementu wapiennego, z powodu szybkiego przechodzenia do roztworu jonów wapniowych pochodzących z hydrolizy alitu.
EN
The thaumasite was obtained using two routes: 1) from the exposure of Portland limestone cement pastes, with 30% limestone, to 4% magnesium sulfate solution for 3 months at 7°C, 2) through the carbonation of an ettringite-sodium silicate mix at 7°C, followed by the rise of pH with lime. The phases formed were examined by XRD, infrared spectroscopy, and scanning electron microscopy. The thaumasite after 2 months of exposure of the limestone cement to sulfate solution was formed. It is prevented by the addition of specific chemicals that reduce calcium and sulfate ions. The prevention is confirmed by microstructure analysis and compressive strength measurement. The mechanism of thaumasite formation is explained by the formation of an intermediate phase composed of a carbonated silica gel, which incorporates relicts of the decomposed ettringite. This phase transforms to thaumasite through the liquid phase pH rise by lime. The results support previous literature published as early as 2003 and suggested the formation of an intermediate phase which was the thaumasite, the product of sulfate attack. The present work was defining the nature of this phase. This phase was not detected in the first route of the Portland limestone cement system because of the rapid rate of lime supply, from the alite hydrolysis.
EN
Information Technology (IT) is a complex domain. In order to properly manage IT related processes, several frameworks including ITIL (Information Technologies Infrastructure Library), COBIT (Control OBjectives for Information and related Technologies), IT Service CMMI (IT Service Capability Maturity Model) and many others have emerged in recent decades. Meanwhile, the prevalence of Agile methods has increased, posing the coexistence of Agile approach with different IT frameworks already adopted in organizations. More specifically, the pursuit of being agile in the area of digitalization pushes organizations to go for agile transformation while preserving full compliance to IT frameworks for the sake of their survival. The necessity for this coexistence, however, brings its own challenges and solutions for harmonizing the requirements of both parties. In this paper, we focus on harmonizing the requirements of COBIT and Scrum in a same organization, which is especially challenging when a full compliance to COBIT is expected. Therefore, this study aims to identifying the challenges of and possible solutions for the coexistence of Scrum and COBIT (version 4.1 in this case) in an organization, by considering two case studies: one from the literature and the case of Akbank delivered in this study. Thus, it extends the corresponding previous case study from two points: adds one more case study to enrich the results from the previous case study and provides more opportunity to make generalization by considering two independent cases.
EN
The positivity of fractional descriptor linear discrete-time systems is investigated. The solution to the state equation of the systems is derived. Necessary and sufficient conditions for the positivity of fractional descriptor linear discrete-time systems are established. The discussion is illustrated with numerical examples.
EN
The positivity of fractional descriptor linear continuous-time systems is investigated. The solution to the state equation of the systems is derived. Necessary and sufficient conditions for the positivity of fractional descriptor linear continuous-time systems are established. The considerations are illustrated by numerical examples.
EN
In this paper, we first study a composite relaxed resolvent operator and prove some of its properties. After that, we introduce a Yosida approximation operator based on the composite relaxed resolvent operator and demonstrate some properties of the Yosida approximation operator. Finally, we obtain the solution of a system of Yosida inclusions by applying these concepts.We construct a conjoin example in support of many concepts derived in this paper. Our concepts and results are new in the literature and can be used for further research.
EN
In this paper, we present some results concerning the existence and the attractivity of solutions for some functional integral equations of Hadamard fractional order. We use an extension of the Burton-Kirk fixed point theorem in Fréchet spaces.
EN
In the paper we found the coefficient relations for which the differential system of the special case of the Stewart-Levin model has a two-parameter family of solutions and the general solution in an analytical form. This model describes the dynamics of the unstable strains of two micro-organisms when the specific consumption rate of a substrate by both the plasmid-bearing and the plasmid-free organisms are given by the Mono function, and the half-saturation constants are equal. The example shows the procedure for finding concrete relations connecting the unknown functions and time. Also, a relation between the functions of the microorganisms’ densities was built. The visualization of all three functions is presented. The coincidence in the graphs of the functions built by analytical and numerical methods is shown.
PL
W artykule określono relacje współczynników, dla których układ różniczkowy specjalnego modelu Stewart-Levina ma dwuparametryczne rozwiązanie i ogólne rozwiązanie w postaci analitycznej. Model ten opisuje dynamikę niestabilnych szczepów dwóch mikroorganizmów, gdy stopień zużycia substratu zarówno przez mikroorganizm posiadający wektor nośnikowy, jak i wektor pusty jest określony za pomocą funkcji Mono przy założeniu, że stałe połowicznego wysycenia są równe. Przykład ten prezentuje procedurę odkrywania specyficznych powiązań łączących nieznane dotąd funkcje w danym przedziale czasowym. Dodatkowo w artykule przedstawiono związek między gęstością mikroorganizmów, a pełnioną przez nie funkcją. Zależności przedstawione na wykresach otrzymano przy użyciu metod analitycznych i numerycznych.
EN
Metathesis ionic exchange reaction process was used to synthesize a novel nonlinear optical material: 4-N,N-dimethylamino-4′- N′-methylstilbazolium 2,4-dimethylbenzenesulfonate (DSDMS). The growth of DSDMS single crystals was carried out by adopting the solution growth technique. The crystal perfection and lattice parameters were elucidated from single XRD and powder XRD, respectively and its morphology was interpreted by WinXMorph program. FT-IR and Raman spectral analyses confirmed the existence of functional groups and their corresponding vibrational modes. UV-Vis spectral studies revealed the optical transmission region. Mechanical stability of the crystal was determined from Vickers microhardness number Hv, Meyer’s index n and elastic stiffness constant C11. Dielectric and thermal behavior of the grown crystal were elucidated by using impedance analyser and thermogravimetric analysis.
EN
Factional Discrete-time linear systems with fractional different orders are addressed. The Weierstrass-Kronecker decomposition theorem of the regular pencil is extended to the descriptor fractional discrete-time linear system with different fractional orders. Using the extension, method for finding the solution of the state equation is derived. Effectiveness of the method is demonstrated on a numerical example.
EN
A transient analytical model is worked out for predicting seepage from a ponded field of infinite extent to a network of equally spaced ditch drains in a homogeneous and anisotropic soil underlain by an impervious barrier at a finite distance from the surface of the soil. The solution can account for finite width and finite level of water in the ditches, finite penetration of the drains in the soil, and also a variable ponding field at the surface of the soil. The study highlights the fact that the transient state duration of a partially penetrating ponded drainage scenario may be considerable should the drains be dug in a lowly conductive soil with a high storage coefficient, particularly if the underlying impervious layer lies at a large distance from the bottom of the ditches and the separation between the adjacent ditches is also large at the same time.
EN
The possibility of producing nano-sized coatings by thermal spray processes seems to be very interesting for many industrial applications. Due to the small size of the grains, it is possible to achieve the properties which are not observed in the micrometric scale on the same kind of material. The aim of the current work is to present the alternative methods for conventional powder plasma spraying (APS) which is well known technology for deposition of micron-sized coatings using powder feedstock. Two plasma spraying processes with liquid feedstock were used – suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS) using aqueous solution directly from wet chemical precipitation process. All experiments were performed based on hydroxyapatite, which is a very important material for biomedical applications. Coatings were produced by three mentioned methods but the deposition process was realized using only one spray set-up equipped with SG-100 plasma torch. Short background of the three different processes performed followed by a short description of liquid feedstock preparation is presented. Microstructure investigation and phase composition analysis of the prepared coatings were carefully characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. Finally, the analysis and comparison of coatings deposited by different plasma spray processes were discussed.
PL
Możliwość wytwarzania powłok o budowie nanometrycznej wydaje się być bardzo interesująca pod kątem ich zastosowania w wielu gałęziach przemysłu. Dzięki bardzo drobnoziarnistej strukturze możliwe jest osiągnięcie właściwości powłok, które nie są możliwe do zaobserwowania w tych samych materiałach lecz w skali mikro. Celem niniejszej pracy jest przedstawienie alternatywnych metod dla konwencjonalnego natryskiwania plazmowego (APS), które jest dobrze poznanym procesem wytwarzania powłok charakteryzująch się budową mikrometryczną. Zaprezentowano dwa nowe procesy natryskiwania plazmowego z fazy ciekłej – natryskiwanie plazmowe zawieisn (SPS) oraz natryskiwanie plazmowe roztworów (SPPS). Wszystkie eksperymenty przeprowadzono z wykorzystaniem hydroksyapatytu, który jest bardzo istotnym materiałem dla zastosowań biomedycznych. Powłoki zostały wytworzone z użyciem trzech wymienionych technologii, jednak proces natryskiwania realizowany był za pomocą jednego stanowiska wyposażonego w palnik plazmowy SG-100. W pracy przedstawiono zarys teoretyczny wykorzystanych metod natryskiwania wraz z opisem procedury przygotowania materiału wejściowego (proszku, zawiesiny oraz roztworu). Następnie przedstawiono badania mikrostruktury i analizę składu fazowego przygotowanych powłok, które zostały wykonane z wykorzystaniem skaningowej mikroskopii elektronowej (SEM) i dyfrakcji promieni rentgenowskich (XRD). Przeprowadzono również analizę i porównanie powłok wykonanych z użyciem różnych procesów natryskiwania plazmowego.
PL
W artykule przedstawiono wyniki badań derywatograficznych roztworów SnCl4·5H2O+IPA używanych do wytwarzania cienkich sensorycznych warstw dwutlenku cyny. Istotnym etapem procesu formowania ostatecznych właściwości warstwy SnO2 jest wygrzewanie w temperaturze do 1000°C żelowej warstwy pozostającej na podłożu po etapie rozwirowania. Przemiany, jakim podlega roztwór w trakcie procesu wirowania, a następnie wygrzewania mają decydujący wpływ na ostateczne właściwości warstwy. Przemiany, jakie zachodzą w strukturze warstwy SnO2 porównywano z morfologią powierzchni warstwy badaną przy wykorzystaniu skaningowej mikroskopii elektronowej.
EN
This paper gives a result of the derivatographic investigation of SnCl4·5H2O+IPA solutions, which are used to production of tin dioxide thin sensoric films. The most important step in this process is forming the final properties of spinned SnO2 gel layer during the annealing at a temperature to 1000°C. The transformations, which occur in the solution during the process of spinning and annealing, have a decisive influence on the final properties of the layer. Transformations taking place in the structure of the SnO2 layer are in corelation with the surface morphology examined by scanning electron microscopy.
EN
Method for finding of the solution of the state equation for time-varying fractional discrete-time linear systems is proposed and computer algorithm is presented. The effectiveness of the proposed algorithm is demonstrated on numerical examples.
EN
We consider the median solution of the Newsvendor Problem. Some properties of such a solution are shown through a theoretical analysis and a numerical experiment. Sometimes, though not often, median solution may be better than solutions maximizing expected profit, or maximizing minimum possible, over distribution with the same average and standard deviation, expected profit, according to some criteria. We discuss the practical suitability of the objective function set and the solution derived, for the Newsvendor Problem, and other such random optimization problems.
EN
An industrial landscape and industrial agglomerations have a whole series of characteristic properties and features that distinguish them markedly from a natural landscape. In the beginning of the 19th century, industrial landscapes began to be formed in places of finding of some of various types of natural resources of the state concerned. Subsequently, towns with another big technical infrastructure changing the natural landscape pattern have been developed in their surroundings. At present, some industrial zones can also be regarded as industrial landscapes. A primary feature of all industrial landscapes, especially heavy industrial landscapes, is emission releases to air and gradual contamination of groundwater and surface water due to industrial activities. Although emissions remain in air for a relatively short time, then contamination, especially groundwater contamination, has long persistence and acts very frequently even after termination of source operation. With reference to the fact that water is a precondition for the life of humans, fauna, flora and the functions of infrastructure of towns and municipalities, it is necessary to cope with the effects of water contamination in a way that minimizes the given risks and maximizes the result of the solution adopted. The following article defines natural and anthropogenic threats arising in an industrial landscape, their negative influences on aquatic ecosystems and a means of minimizing their negative effects. The effects of these threats are to be reassessed with regard to the changing world climate and a gradual decrease in freshwater resources. The reassessment is necessary because the volume of inorganic contaminants in old environmental burdens remains the same, but the volume of water decreases, and thus the current quality of water for drinking, agriculture and industrial needs changes.
PL
Krajobraz oraz aglomeracje przemysłowe przedstawiają całe zestawy charakterystycznych cech i właściwości, które znacząco odróżniają je od krajobrazu naturalnego. Na początku XIX wieku krajobrazy przemysłowe zaczęły się formować w miejscach wydobywania różnego rodzaju surowców naturalnych. Następnie w okolicy rozwinęła się infrastruktura techniczna, która odmieniła elementy krajobrazu naturalnego. Obecnie niektóre strefy przemysłowe również uważane są za krajobrazy przemysłowe. Podstawową cechą krajobrazów przemysłowych, a w szczególności krajobrazu przemysłu ciężkiego, jest emisja do powietrza oraz stopniowe zanieczyszczenie wód lądowych i powierzchniowych. Jest to spowodowane aktywnością przemysłową. Choć emisja pozostaje w powietrzu w relatywnie krótkim czasie, to z kolei zanieczyszczenie wód, w szczególności lądowych, pozostaje na bardzo długo, a jego skutki zagrażają na długo po zakończeniu aktywności przemysłowej. Biorąc pod uwagę fakt, że woda to podstawowy warunek istnienia ludzkości, fauny oraz flory oraz efektywnego działania infrastruktury miejskiej i gminnej, ważne jest znalezienie takiego sposobu walki z efektami zanieczyszczeń wody, który zminimalizuje ponoszone ryzyko. Niniejszy artykuł omawia naturalne i antropogeniczne zagrożenia powstające w krajobrazie przemysłowym, ich negatywny wpływ na ekosystem wodny, oraz sposoby na minimalizację tego wpływu. Oddziaływanie tych zagrożeń należy ponownie ocenić ze względu na zmieniający się światowy klimat oraz stopniowy zanik źródeł świeżej wody pitnej. Ponowna ocena jest konieczna, ponieważ o ile ilość zanieczyszczeń nieorganicznych w dawniej obciążanych środowiskach pozostaje taka sama, to ilość wody maleje, dlatego obecna jakość wód pitnych oraz na potrzeby rolnictwa i przemysłu wymaga poprawy.
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