Wyniki wyszukiwania - BazTech

1

Investigation of asymmetric twin-rudder load behaviour through free-running model tests

Efremov Dobrin, Milanov Evgeni

Polish Maritime Research

|

2023

|

nr 3

4--11

EN

During tight manoeuvres, twin-screw ships equipped with two rudders located in the propeller slip stream experience a fairly large imbalance in the hydrodynamic loads on the propeller and rudders. To investigate the phenomenon of rudder asymmetric load in some depth, manoeuvring experiments based on a free-running model were set up in which the kinematics of the model, the forces on the rudder and the stock moment were recorded. In parallel, with the aim of obtaining an exact estimation of free-stream characteristics of the rudder blade, corresponding wind tunnel experiments were also performed. Based on the results of this investigation, an analysis of the interaction effects within the hull-propeller-rudder system was performed and some conclusions were drawn.

2

Development of an Adaptive Genetic Algorithm to Optimize the Problem of Unequal Facility Location

Budi Hendrik Setia, Elveny Marischa, Zhuravlev Pavel, Jalil Abduladheem Turki, Al-Janabi Samaher, Alkaim Ayad F., Saleh Marwan Mahmood, Shichiyakh Rustem Adamovich, Sutarto

Foundations of Computing and Decision Sciences

|

2022

|

Vol. 47, No. 2

111--125

EN

The problem of unequal facility location involves determining the location of a set of production equipment whose dimensions are different, as well as the interrelationships between each of them. This paper presents an efficient method for optimizing the problem of unequal facility layouts. In this method, the genetic algorithm is improved and developed into an adaptive genetic algorithm. In this algorithm, the mutation operator is applied only when the similarity of chromosomes in each population reaches a certain level. This intelligence prevents jumps in situations where they are not needed and reduces computational time. In order to measure the performance of the proposed algorithm, its performance is compared with the performance of conventional genetic algorithms and refrigeration simulators. Computational results show that the adaptive genetic algorithm is able to achieve higher-quality solutions.

3

Functionalization of carbon biomaterials surfaces: functional groups and nanoparticles

Pajerski Wojciech, Chytrosz Paulina, Golda-Cepa Monika, Pawlyta Mirosława, Reczyński Witold, Ochonska Dorota, Brzychczy-Wloch Monika, Kotarba Andrzej

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 163

40

4

Framework of machine criticality assessment with criteria interactions

Jasiulewicz–Kaczmarek Małgorzata, Antosz Katarzyna, Żywica Patryk, Mazurkiewicz Dariusz, Sun Bo, Ren Yi

Eksploatacja i Niezawodność

|

2021

|

Vol. 23, no. 2

207--220

EN

Criticality is considered as a fundamental category of production planning, maintenance process planning and management. The criticality assessment of machines and devices can be a structured set of activities allowing to identify failures which have the greatest potential impact on the company’s business goals. It can be also used to define maintenance strategies, investment strategies and development plans, assisting the company in prioritizing their allocations of financial resources to those machines and devices that are critical in accordance with the predefined business criteria. In a criticality assessment process many different and interacting criteria have to be taken into consideration, despite the fact that there is a high level of uncertainty related to various parameters. In addition, not all assessment criteria are equally important. Therefore, it is necessary to determine the weight of each criterion taking into account different requirements of machine criticality process stakeholders. That is why a novel model of a machine criticality assessment is proposed in this paper. The model extends the existing methods of assessing machines criticality, taking into account not only the importance of machine criticality assessment criteria, but also possible interactions between them.

5

Działanie łączne substancji chemicznych wpływających szkodliwie na rozrodczość - charakterystyka problemu

Miranowicz-Dzierżawska Katarzyna

Bezpieczeństwo Pracy : nauka i praktyka

|

2021

|

nr 1

14-17

PL

Substancje wpływające szkodliwie na rozrodczość (również te, które działają poprzez zaburzanie gospodarki hormonalnej organizmu) są klasyfikowane zgodnie z rozporządzeniem Parlamentu Europejskiego i Rady (WE) nr 1272/2008. W tym rozporządzeniu zostały ustalone zasady, na jakich klasyfikuje się również mieszaniny takich substancji, jednak w dalszym ciągu problemem pozostaje ocena skutków łącznego narażenia na substancje pochodzące z wielu różnych źródeł bądź rozprzestrzeniających się różnymi drogami. W artykule omówiono zagadnienia związane z oddziaływaniem na organizm mieszanin substancji chemicznych, wśród których istnieje możliwość wzajemnych interakcji, co powoduje, że mieszaniny mogą stwarzać nieoczekiwanie duże zagrożenie dla zdrowia narażonego na ich działanie człowieka.

EN

Substances toxic to ability to propagate (including those acting by disrupting the endocrine system) are classified in accordance with Regulation (EC) No 1272/2008 of the European Parliament and of the Council. Pursuant to this regulation, the rules on classification mixtures of such substances are also established, however, the assessment of the effects of combined exposure to substances from many different sources or spread through different routes remains are still a problem. This article discusses the problem of exposure to chemical substances mixtures, among which there is a possibility of mutual interaction, causing that mixtures may pose unexpectedly high hazards to human health.

6

Reconsidering Land System Changes in Borderlands: Insights from the China-ASEAN Borderland

Hua Xiaobo, Kono Yasuyuki

Problemy Ekorozwoju

|

2020

|

Vol. 15, nr 1

179--187

EN

This study contributes to the literature on how to explicitly describe, track, and interpret the structure and dynamics of land systems in borderlands. The shift in land system science analytics from place-based toward larger-scale analysis of interactions and connections in a globalized context provides an opportunity to synthesize the knowledge about borderlands. This paper argues that studies on land system changes in borderlands need to thoroughly link the features of borderland regions with multiple interactions – on either or both sides of a border – rather than simply focusing on shifts within closed national boundaries. Furthermore, this paper provides important insights that can advance existing approaches to track and interpret changes in the land systems of borderlands.

PL

Niniejsze opracowanie przyczynia się do jednoznacznego opisu, śledzenia i interpretacji struktury i dynamiki systemów lądowych na obszarach przygranicznych. Przejście w analizie nauk o systemie lądowym z analizy opartej na miejscu na analizę interakcji i połączeń na większą skalę w zglobalizowanym kontekście daje możliwość nowej syntezy wiedzy na temat pogranicza. W niniejszym artykule wykazuje się, że badania zmian w systemie lądowym na obszarach przygranicznych muszą dokładnie wiązać cechy regionów przygranicznych z wieloma interakcjami – po jednej lub po obu stronach granicy – zamiast koncentrować się wyłącznie na przesunięciach w obrębie zamkniętych granic krajowych. Ponadto niniejszy artykuł zawiera ważne informacje, które mogą usprawnić istniejące podejścia do śledzenia i interpretacji zmian w systemach lądowych pogranicza.

7

Odpowiedź immunologiczna organizmów wyższych na obecność nanocząstek w środowisku

Sieradzki Marek

Laboratorium - Przegląd Ogólnopolski

|

2020

|

nr 1

24--30

PL

Nanocząstki są niezwykle małymi składnikami materii o rozmiarze nieprzekraczającym wielkości 100 nm w jednym z trzech wymiarów. Powszechnie występują w środowisku w sposób naturalny lub jako produkt celowej albo niezamierzonej działalności człowieka. Kontakt kręgowców z nimi jest więc nieunikniony. Okazuje się, że nanocząstki oddziałują ze składnikami układu immunologicznego tych organizmów. Mogą pobudzać albo hamować składowe wrodzonej i nabytej odporności u kręgowców w zależności od swoich właściwości fizyczno-chemicznych i strukturalnych. Coraz większa jest wiedza dotycząca oddziaływania nanocząstek z białkami układu dopełniacza (komplementu). Nanocząstki mogą oddziaływać ze składnikami kaskady komplementu na różnych etapach aktywacji, tj. od etapu rozpoznania patogenów, przez działanie jego składników, po utworzenie kompleksu atakującego błonę. W tym zakresie oddziałują na komplement hamująco bądź aktywująco, w zależności od właściwości fizyczno-chemicznych. Wpływają również na komórki układu immunologicznego, takie jak makrofagi. Obserwuje się także udział nanocząstek w rozwoju i przebiegu alergii. Dokładne poznanie powyższych oddziaływań daje możliwości zrozumienia wpływu nanocząstek znajdujących się w środowisku na organizmy zwierząt kręgowych i poznania korzyści oraz konsekwencji jakie mogą z tego wynikać.

EN

Nanoparticles are extremely small components of matter not exceeding 100 nm in one of the three dimensions. They commonly occur in the environment naturally or as a product of intentional or unintentional human activity. The contact of vertebrates with them is therefore inevitable. lt turns out that nanoparticles interact with the components of the immune system of these organisms. They can stimulate or inhibit the components of innate and acquired immunity in vertebrates depending on their physicochemical and structural properties. Knowledge about the interaction of nanoparticles with complement proteins is increasing. Nanoparticles can interact with the components of the complement cascade of various stages of activation, i.e. from the pathogen recognition stage, to the action of its components, to the formation of the membrane attack complex. In this regard, they inhibit or stimulate the complement depending on the physicochemical properties. They also affect immune cells such as microphages. The participation of nanoparticles in the development and course of allergies is also observed. A thorough understanding of the above interactions gives the opportunity to understand the impact of nanoparticles in the environment on vertebrate animals and to know the consequences and benefits that may result from this.

8

Interaction of selected pesticides with mineral and organic soil components

Barchańska Hanna, Czaplicka Marianna, Kyzioł-Komosińska Joanna

Archives of Environmental Protection

|

2020

|

Vol. 46, no. 3

80--91

EN

The pesticide persistence, in particular in soils, often significantly exceeding the declarations of their manufacturers is surprising. There are many publications devoted to the explanation of this phenomenon in the fi eld literature, but the diverse research methodologies used may lead to the ambiguous conclusions. On the basis of the collected literature, the attempt was made to systematize the available information on the interactions of commonly used groups of pesticides with individual soil components. The complex mechanisms of interactions between pesticides and soil based on van der Waals forces, ionic and covalent bonding, ligand exchange and charge transfer complexes formation were demonstrated. It was also proved that the nature of interactions is strictly dependent on the structure of the pesticide molecule. The conclusion of the review may contribute to the choice of plant protection products that, in addition to their effectiveness, are as little ballast for the environment as possible.

9

Propozycja zastosowania wybranych elementów teorii wymiany w celu identyfikacji procesów integracji społecznej w kontekście kształtowania bezpieczeństwa

Szykuła-Piec B.

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

|

2018

|

Nr 68 (tom 4)

277--290

PL

Celem artykułu jest zwrócenie uwagi na możliwość wykorzystania wybranych konstruktów teorii wymiany, do modelowania interakcji społecznych. Nie byłoby nic nowego w tym ujęciu, gdyby nie fakt zakotwiczenia rozważań w kontekście potrzeb, a ściślej mówiąc, dostarczania bezpieczeństwa i wzajemnym udziale w jego kreowaniu. Autorka zakłada, że bezpieczeństwo − zdefiniowane jako usługa dostarczana przez państwo w sposób kolegialny − może być istotnym przedmiotem wymiany społecznej. Przez prześledzenie wybranych teorii potrzeb, hierarchizujących konieczność ich zaspokajania oraz przywołanie głównych tez twórców teorii wymiany, podjęto próbę ukierunkowania rozważań na rodzaje interakcji oraz na to, co warunkuje ich istnienie.

EN

The aim of this study is to draw the attention to the possibility of using selected constructs of the exchange theory to the model of social interactions. There would be nothing new in this approach, if not the fact anchor considerations in the context of the needs, and more specifically the provision of the security and mutual participation in its creation. The author assumes that security defined as a service provided by the state in a collegial way can be an important subject of the social exchange. Through selected theory of needs which hierarchies and also recalls the main founders of the exchange theory an attempt to focus discussion on the forms of the interaction, and on the factors which determine their existence was made.

10

Wpływ nałogu palenia na interakcje pierwiastków fizjologicznych z Mo, Li, Ti, Sr w strukturze mineralnej złogów pęcherzyka żółciowego

Musielińska R., Kwapuliński J., Szady B., Szady A.

Chemistry, Environment, Biotechnology

|

2018

|

Vol. 21

30--37

PL

Celem badań było określenie kierunku zmian zawartości Ti, Li, Mo, Sr w nawiązaniu do zmian zawartości czterech podstawowych pierwiastków fizjologicznych (Mg, K, Ca, Na) w strukturze mineralnej hydroksyapatytów złogów pęcherzyka żółciowego, na podstawie analizy zmian ilorazów przeciętnej zawartości badanych pierwiastków w hydroksyapatytach złogów pęcherzyka żółciowego i zawartości poszczególnych metali traktowanych jako odnośnikowe. Zawartość pierwiastków w złogach pęcherzyka żółciowego pozyskanych podczas cholecystektomii oznaczano metodą emisyjnej spektrometrii z plazmą wzbudzoną indukcyjnie (ICP-AES) z wykrywalnością 0,01µg/g. Obecność i kierunek zmian badanych pierwiastków w złogach pęcherzyka żółciowego obrazowana ilorazem przeciętnej zawartości danego pierwiastka Me+n i przeciętnej zawartości pierwiastków odnośnikowych Me+k jest determinowana płcią, nałogiem palenia oraz miejscem zamieszkania w zależności od stopnia zanieczyszczenia powietrza tymi pierwiastkami. Graficzny obraz zmian ilorazu Me+n/Me+k w odniesieniu do przeciętnej zawartości pozostałych pierwiastków odnośnikowych - Me+k wchodzących w skład struktury mineralnej złogów pęcherzyka żółciowego pozwala wskazać na znaczenie fizjologiczne danego pierwiastka w procesie jego złożonej kumulacji w patogenie.

EN

The aim of this study was to determine the direction of changes in the content of Ti, Li, Mo, Sr in relation to changes in the content of four basic physiological elements (Mg, K, Ca, Na) in the mineral structure of hydroxyapatites of gallbladder deposits, on the basis of the analysis of changes in the quotient of the average content of the tested elements in hydroxyapatites of gallbladder deposits and the content of individual metals treated as references. The content of elements in gallstones deposits obtained during cholecystectomy was determined by inductively induced plasma emission spectrometry (ICP-AES) with a detection rate of 0,01µg/g. The presence and direction of changes in the examined elements in the gallbladder deposits, illustrated by the quotient of the average content of a given Me+n element and the average content of the Me+k reference elements, is determined by sex, smoking addiction and place of residence depending on the degree of air pollution with these elements. The graphical picture of changes in the Me+n/Me+k ratio in relation to the average content of other reference elements - Me+k, which are part of the mineral structure of gallstones deposits - allows to indicate the physiological significance of a given element in the process of its complex accumulation in pathogenesisethods.

11

Colloidal quantum dots conjugated with human serum albumin : interactions and bioimaging properties

Wojnarowska-Nowak R., Polit J., Zięba A., Stolyarchuk I. D., Nowak S., Romerowicz-Misielak M., Sheregii E. M.

Opto-Electronics Review

|

2017

|

Vol. 25, No. 2

137--147

EN

Quantum dots, due to their unique optical properties, constitute significant materials for many areas of nanotechnology and bionanotechnology. This work presents a review of researches dedicated to the interaction between quantum dots (QDs) with human serum albumin (HSA) and human cell culture as important for nanomedicine applications. The optical properties of bio-nanocomplexes formed by nanoparticles including colloidal QDs (e.g., CdTe, CdS, CdCoS) and albumin are displayed. The absorption spectra show that adding HSA to colloidal QDs leads to a gradual decrease of absorption and broadening of the exciton structure. The photoluminescence quenching results indicate that the quenching effect of QDs on HSA fluorescence depends on the size and temperature. The nature of quenching is rather static, resulting in forming QD-HSA complexes. The CdTe QD-HSA complexes show chemical stability in a PBS buffer. Furthermore, it is stable in cytoplasm and suitable for cell labeling, tracking, and other bioimaging applications.

12

Bronchial Mucus as a Complex Fluid: Molecular Interactions and Influence of Nanostructured Particles on Rheological and Transport Properties

Odziomek M., Kalinowska M., Płuzińska A., Rożeń A., Sosnowski T. R.

Chemical and Process Engineering

|

2017

|

Vol. 38, nr 2

217--229

EN

Transport properties of bronchial mucus are investigated by two-stage experimental approach focused on: (a) rheological properties and (b) mass transfer rate through the stagnant layer of solutions of mucus components (mucine, DNA, proteins) and simulated multi-component mucus. Studies were done using thermostated horizontal diffusion cells with sodium cromoglycate and carminic acid as transferred solutes. Rheological properties of tested liquids was studied by a rotational viscometer and a cone-plate rheometer (dynamic method). First part of the studies demonstrated that inter-molecular interactions in these complex liquids influence both rheological and permeability characteristics. Transfer rate is governed not only by mucus composition and concentration but also by hydrophobic/hydrophilic properties of transported molecules. Second part was focused on the properties of such a layer in presence of selected nanostructured particles (different nanoclays and graphene oxide) which may be present in lungs after inhalation. It was shown that most of such particles increase visco-elasticity of the mucus and reduce the rate of mass transfer of model drugs. Measured effects may have adverse impact on health, since they will reduce mucociliary clearance in vivo and slow down drug penetration to the bronchial epithelium during inhalation therapy.

13

An Influence of Parameters of Micro-electrical Discharge Machining on Wear of Tool Electrode

Puthumana G.

Archive of Mechanical Engineering

|

2017

|

Vol. LXIV, nr 2

149--163

EN

To achieve better precision of features generated using the micro-electrical discharge machining (micro-EDM), there is a necessity to minimize the wear of the tool electrode, because a change in the dimensions of the electrode is reflected directly or indirectly on the feature. This paper presents a novel modeling and analysis approach of the tool wear in micro-EDM using a systematic statistical method exemplifying the influences of capacitance, feed rate and voltage on the tool wear ratio. The association between tool wear ratio and the input factors is comprehended by using main effect plots, interaction effects and regression analysis. A maximum variation of four-fold in the tool wear ratio have been observed which indicated that the tool wear ratio varies significantly over the trials. As the capacitance increases from 1 to 10 nF, the increase in tool wear ratio is by 33%. An increase in voltage as well as capacitance would lead to an increase in the number of charged particles, the number of collisions among them, which further enhances the transfer of the proportion of heat energy to the tool surface. Furthermore, to model the tool wear phenomenon, a regression relationship between tool wear ratio and the process inputs has been developed.

14

Application of a linked stress release model in Corinth Gulf and Central Ionian Islands (Greece)

Mangira O., Vasiliadis G., Papadimitriou E.

Acta Geophysica

|

2017

|

Vol. 65, no. 3

517--531

EN

Spatio-temporal stress changes and interactions between adjacent fault segments consist of the most important component in seismic hazard assessment, as they can alter the occurrence probability of strong earthquake onto these segments. The investigation of the interactions between adjacent areas by means of the linked stress release model is attempted for moderate earthquakes (M ≥ 5.2) in the Corinth Gulf and the Central Ionian Islands (Greece). The study areas were divided in two subareas, based on seismotectonic criteria. The seismicity of each subarea is investigated by means of a stochastic point process and its behavior is determined by the conditional intensity function, which usually gets an exponential form. A conditional intensity function of Weibull form is used for identifying the most appropriate among the models (simple, independent and linked stress release model) for the interpretation of the earthquake generation process. The appropriateness of the models was decided after evaluation via the Akaike information criterion. Despite the fact that the curves of the conditional intensity functions exhibit similar behavior, the use of the exponential-type conditional intensity function seems to fit better the data.

15

Molecular Dynamics Simulation Studies of the CL-20/DNB Co-crystal

Sun T., Xiao J. J., Ji G. F., Zhao F., Xiao H. M.

Central European Journal of Energetic Materials

|

2016

|

Vol. 13, no. 3

677--693

EN

Molecular dynamics (MD) simulation was conducted for a DNB (1,3-dinitrobenzene) crystal, a ε-CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane) crystal, a CL-20/DNB co-crystal and a CL-20/DNB composite. From the calculated maximum bond length (Lmax) of the N−NO2 trigger bond, the cohesive energy density (CED) and the binding energy (Ebind), it was found that the CL-20/DNB co-crystal is more insensitive than its composite. Its thermal stability is also better than that of its composite. The pair correlation function (PCF) analysis method was applied to investigate the interfaces between different molecular layers in the CL-20/DNB co-crystal, and in the composite. Additionally, the calculated mechanical data showed that the moduli of the CL-20/DNB co-crystal and its composite are smaller and their elastic elongation and ductility are better than those of the ε-CL-20 and DNB crystals.

16

Sterowanie i prowadzenie ruchu systemu elektroenergetycznego – Komitet Studiów C2

Madajewski K.

Energetyka

|

2015

|

nr 3

200--204

PL

Omówiono referaty, których treścią są nowe problemy, jakie pojawiły się w obszarze planowania i prowadzenia ruchu systemu elektroenergetycznego w czasie rzeczywistym oraz sposoby ich rozwiązania, do jakich należą: analizy, monitorowanie i sterowanie (w tym regulacja napięcia, regulacja częstotliwości, stabilność kątowa), a także wykorzystanie dynamicznej obciążalności linii czy usługi systemowe, w tym rezerwa operacyjna. Druga grupa zagadnień to interakcje między przesyłem a dystrybucją w procesie prowadzenia ruchu, a więc interfejsy: przesył, dystrybucja, odbiór, czy też prowadzenie ruchu, rynek. Do interakcji tych zalicza się również: szkolenia i treningi operatorów, świadomość zaistnienia problemów ruchowych, potrzeby w zakresie modelowania i wymiany danych, sterowalność generacji rozproszonej, zarządzanie mocą zwarciową czy odpowiedź popytu.

EN

Discussed were lectures concerning new problems that emerged in the area of a power system real-time operation and control with methods to solve them like analyses, monitoring and control (including voltage control, frequency control and angle stability) and also referring to the use of dynamic network capacity or system services (including the operating reserve). The second group of problems were interactions between transmission and distribution in the system operation process that meant interfaces like transmission, distribution and consumption together with running of the system and the energy market. These interactions also include operator trainings, awareness of operational problems existence, requirements related to modeling and data exchange, distributed generation controllability, short-circuit power management or demand response.

17

The effect of soil risk element contamination level on the element contents in Ocimum basilicum L.

Růžičková P., Száková J., Havlík J., Tlustoš P.

Archives of Environmental Protection

|

2015

|

Vol. 41, no. 2

47--53

EN

Red basil (Ocimum basilicum L.) cv. Red Rubin was cultivated in model pot experiment in the soil amended by arsenic, cadmium and lead solutions in stepwise concentrations representing the soil concentration levels of former mining area in the vicinity of Příbram, Czech Republic. The element levels added to the soil reached up to 40 mg Cd, 100 mg As, and 2000 mg Pb per kg of soil. Moreover, essential macro-and microelements as well as cyanidine contents were investigated to assess their potential interactions with the risk elements. The extractable element portions in soils determined at the end of vegetation period differed according to the individual elements. Whereas the plant-available (extractable with 0.11M CH3COOH) content of Cd represented 70-100% of the added Cd, the mobile portion of Pb did not exceed 1%. The risk element content in plants reflected the increasing element contents in soil. The dominant element portions remained in plant roots indicating the limited translocation ability of risk elements to the aboveground biomass of this plant species. Although the risk element contents in amended plants significantly increased, no visible symptoms of phytotoxicity occurred. However, the effect of enhanced risk element contents on the essential element uptake was assessed. Considering inter-element relationships, elevated sulphur levels were seen in amended plants, indicating its possible role of phytochelatin synthesis in the plants. Moreover, the molybdenum contents in plant biomass dropped down with increasing risk element uptake by plants confirming As-Mo and Cd-Mo antagonism. The increasing content of cyanidine in the plant biomass confirmed possible role of anthocyanins in detoxification mechanism of risk element contaminated plants and suggested the importance of anthocyanin pigments for risk element tolerance of plants growing in contaminated areas.

18

Perspectives on Uncertainty and Risk in Rough Sets and Interactive Rough-Granular Computing

Jankowski A., Skowron A., Swiniarski R. W.

Fundamenta Informaticae

|

2014

|

Vol. 129, nr 1/2

69--84

EN

We discuss an approach for dealing with uncertainty in complex systems. The approach is based on interactive computations over complex objects called here complex granules (c-granules, for short). Any c-granule consists of a physical part and a mental part linked in a special way. We begin from the rough set approach and next we move toward interactive computations on c-granules. From our considerations it follows that the fundamental issues of intelligent systems based on interactive computations are related to risk management in such systems. Our approach is a step toward realization of the Wisdom Technology (WisTech) program. The approach was developed over years of work on different real-life projects.

19

Crossed product of a C*-algebra by a semigroup of interactions

Kwaśniewski B. K.

Demonstratio Mathematica

|

2014

|

Vol. 47, nr 2

352--370

EN

The paper presents a construction of the crossed product of a C*-algebra by a commutative semigroup of bounded positive linear maps generated by partial isometries. In particular, it generalizes Antonevich, Bakhtin, Lebedev’s crossed product by an endomorphism, and is related to Exel’s interactions. One of the main goals is the Isomorphism Theorem established in the case of actions by endomorphisms.

20

Method of choosing optimal composition of biomass mixtures

Katelbach-Woźniak A., Niestrój M., Szlęk A.

Archivum Combustionis

|

2014

|

Vol. 34 nr 1

27—34

EN

Biomass has high content of volatile matter, hence devolatilization process is rapid. Necessity of supplying high fluxes of combustion air is usually one of the factor which leads to high values of air excess ratio and, as a consequence to decrease of energy efficiency. However it is possible to use mixture of different sorts of biomasses and thus obtain fuel which might equalize devolatilization rate. In this paper procedure for choosing optimal mixture of given sorts of biomasses based on their composition is presented. First, pyrolysis process of hemicellulose, cellulose and lignin was conducted using thermobalance. Based on the results and assuming that there are no interactions between pure components, optimal composition of the mixture were calculated. In the next step, according to obtained optimal composition, proportions of oak, pine, rape straw and wheat straw were calculated. Finally, pyrolysis of selected biomass mixtures was carried out. It was found that due to the presence of cellulose, which decomposes in very narrow temperature range, all of mixtures are characterized by the devolatilization with local maximum occurring at the temperature around 350°C.