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1
Content available remote CYKL – sposoby na zrównoważone wykorzystanie materiałów stosowanych na wydziałach architektury
Strojny Rafał, Małys Dominika, Wachowska Marta
Teka Komisji Architektury, Urbanistyki i Studiów Krajobrazowych
|
2023
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T. 19, nr 1
54--66
PL
Artykuł dotyczy papieru i tektury jako materiałów będących podstawowym elementem pracy studentów architektury. W dobie cyfryzacji oraz zmian klimatycznych ważne jest zrównoważone podejście do zarządzania materiałami – w tym przypadku wykorzystywanymi na wydziałach architektury. Celem badań była próba znalezienia zrównoważonych metod wykorzystania papieru i tektury przez studentów architektury, a także zwiększenie świadomości od najmłodszych lat. W badaniach wykorzystano technikę wywiadu pogłębionego, metodę badań ilościowych i statystycznych, heurystyczną oraz eksperymentalną. Na podstawie badań oszacowano, iż przez okres pięciu lat studiów architektonicznych zużywa się papier i tekturę w ilości wymagającej do ich produkcji wycięcia ponad 600 drzew. Podejście eksperymentalne obejmowało warsztaty i „burzę mózgów” podczas których studenci rozpatrywali sposoby bardziej zrównoważonego wykorzystania danych materiałów. Efektem tych rozważań jest wystawa CYKL otwarta 10 stycznia 2023 roku na Wydziale Budownictwa i Architektury Politechniki Lubelskiej przez Koło Naukowe Architektury i Budownictwa Ekologicznego „Archinature”. Obejmuje ona instalacje inżynierskie, architektoniczne i artystyczne przedstawiające w nieszablonowy sposób cykl produkcji papieru, cykl jego „życia” oraz przejście do ery cyfrowej w projektowaniu architektonicznym. Wystawę poprzedzały warsztaty dla dzieci ze szkoły podstawowej, które miały czynny wkład w budowę części instalacji. W związku z tym zaproponowano metody na zrównoważone podejście do materiałów wykorzystywanych na wydziałach architektury.
EN
In an era of digitization and climate change, it is important to have a sustainable approach to managing materials – in this case, those used in architecture departments. The aim of the research was to find sustainable methods of using paper and cardboard by architecture students, and to raise awareness from an early age. The research used an in-depth interview technique, a quantitative and statistical research method, a heuristic and an experimental method. Based on the research, it was estimated that during the five years of architectural studies, an amount of paper and cardboard consumed requires more than 600 trees to be cut down for their production. The experimental approach included workshops and “brainstorming” during which students considered ways to use the materials in question more sustainably. The result of these considerations is the “CYKL” exhibition opened on January 10, 2023 at the Faculty of Building and Architecture of Lublin University of Technology by the Koło Naukowe Architektury i Budownictwa Ekologicznego “Archinature”. It includes engineering, architectural and artistic installations depicting in an unconventional way the cycle of paper production, the cycle of its “life” and the transition to the digital era in architectural design. The exhibition was preceded by a workshop for elementary school children, who had active input into the construction of some of the installations.
2
Content available Analysis of the effects of recycling on process control
Silva Cássio R.A., Panuci Victor C., Coutinho Monica R., Conceição Wagner A.S., Andrade Cid M.G.
Polish Journal of Chemical Technology
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2023
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Vol. 25, nr 2
43--55
EN
The union of different devices in order to obtain a specific response for a process is commonly called a control system. For a control system, it is necessary to have one or more controllers. Among the most used in the industrial sector are the PID and PI controllers. Next to these controllers is the control software. Scilab is a good example of control software. It is characterized as free code software, with no cost for its acquisition, in addition to having a large computational power and integrated tools, such as Xcos, intended for modeling and simulation. For the union with Scilab, there is Arduino. Such a mixture can be used, for example, to control liquid levels in tanks. In this context, the present work aims to study the tank-level control system based on PID and PI controllers through the union between Scilab and Arduino. Phenomenological models were developed based on closed-loop control (feedback control system) of the process with two tanks not coupled with recycle. Furthermore, for comparison purposes, two approaches were used for each process: one considering the saturation of the manipulated variable and the other without the presence of such saturation. At first, there was a need to implement an anti-windup system. For tuning the controller parameters, the ISE method was used, executed through a programming code developed in Scilab. The parameters found for the two systems were tested on a made-up experimental bench. Therefore, using the block diagrams and the method here called “ISE method”, satisfactory values were obtained for the control parameters. These were ratified in the tests carried out in the experimental module. Level control was achieved with greater prominence for the PI controller since there is one less parameter to be tuned and processed by the system. This controller provided results close to the PID controller for cycles up to 50%. In general, the PI controller showed maximum response deviations smaller than the PID, such as deviations of 1.55 cm and 2.40 cm, respectively, for the case with 75% recycle. It was also clear the influence of the saturation of the manipulated variable on the system response, but not on the tuning of the controller parameterseters.
3
Content available The crossing numbers of join products of four graphs of order five with paths and cycles
Staš Michal, Timková Mária
Opuscula Mathematica
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2023
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Vol. 43, no. 6
865--883
EN
The crossing number cr(G) of a graph G is the minimum number of edge crossings over all drawings of G in the plane. In the paper, we extend known results concerning crossing numbers of join products of four small graphs with paths and cycles. The crossing numbers of the join products G∗ + Pn and G∗ + Cn for the disconnected graph G∗ consisting of the complete tripartite graph K1,1,2 and one isolated vertex are given, where Pn and Cn are the path and the cycle on n vertices, respectively. In the paper also the crossing numbers of H∗ + Pn and H∗ + Cn are determined, where H∗ is isomorphic to the complete tripartite graph K1,1,3. Finally, by adding new edges to the graphs G∗ and H∗, we are able to obtain crossing numbers of join products of two other graphs G1 and H1 with paths and cycles.
4
Content available On the crossing numbers of join products of W4 + Pn and W4 + Cn
Stas Michal, Valiska Juraj
Opuscula Mathematica
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2021
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Vol. 41, no. 1
95-112
EN
The crossing number cr(G) of a graph G is the minimum number of edge crossings over all drawings of G in the plane. The main aim of the paper is to give the crossing number of the join product W4 + Pn and W4 + Cn for the wheel W4 on five vertices, where Pn and Cn are the path and the cycle on n vertices, respectively. Yue et al. conjectured that the crossing number of Wm + Cn is equal to [formula], for all m,n ≥ 3, and where the Zarankiewicz’s number[formula] is defined for n ≥ 1. Recently, this conjecture was proved for W3 + Cn by Klesc. We establish the validity of this conjecture for W4 + Cn and we also offer a new conjecture for the crossing number of the join product Wm + Pn for m ≥ 3 and n ≥ 2.
5
Content available Review of mechanical vapour compression refrigeration system part 2: performance challenge
Mahmood R. A., Ali O. M., Al-Janabi A., Al-Doori G., Noor M. M.
International Journal of Applied Mechanics and Engineering
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2021
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Vol. 26, no. 3
119--130
EN
Reducing energy consumption and providing high performance for a vapour compression refrigeration system are big challenges that need more attention and investigation. This paper provides an extensive review of experimental and theoretical studies to present the vapour compression refrigeration system and its modifications that can be used to improve system’s performance and reduce its energy consumption. This paper also presents the challenges that can be considered as a gab of research for the future works and investigations. Cooling capacity, refrigerant effect, energy consumption can be improved by using vapour injection technique, natural working fluid, and heat exchanger. Based on the outcome of this paper, vapour injection technique using natural refrigerant such as water can provide ultimate friendly refrigeration system. Future vision for the vapour compression refrigeration system and its new design technique using Computational Fluid Dynamic (CFD) is also considered and presented.
6
Content available The cooling rate of the heated vapor compression cycle in case of using refrigerants R134a, R22, and R600a
Abd-Elhady Mohamed Salama, Melad Emmanoueil Bishara, Abd-Elhalim Mohamed, Seif Alnasr Ahmed
Archives of Thermodynamics
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2021
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Vol. 42, no 2
11--30
EN
The most power consuming part in the vapor compression cycle (VCC) is the gas compressor. Heating the refrigerant under constant volume after the compressor increases the condenser pressure, which consequently increases the cooling rate of the VCC. This study examined the influence of heating different refrigerants, i.e. R143a, R22, and R600a on the cooling rate of the VCC. Four experiments have been performed: the first experiment is a normal VCC, i.e. without heating, while in the second, third, and fourth experiments were carried out to raise the temperature of the refrigerant to 50°C, 100°C, and 150°C. It has been found that heating raises the refrigerant pressure in VCC and thereby improves the refrigerant’s mass flow rate resulting in an improvement in the cooling power for the same compressor power. Heating the refrigerant after the mechanical compressor increases the temperature of the condenser as well as the temperature of the evaporator when using refrigerant R134a, which prevents the refrigeration cycle to be used in freezing applications, however using refrigerant R22 or refrigerant R600a promotes the heated VCC to be used in freezing applications. Refrigerant R600a has the lowest operating pressure compared to R134a and R22, which promotes R600a to be used rather than R134a and R22 from a leakage point of view.
7
Content available Some Ideas about Connected Graphs Isomorphism
Marchenko L., Podgornaya V.
Advances in Computer Science Research
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2018
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Nr 14
105--123
EN
In the paper we investigate the existence of graphs isomorphism and the search for invariants of connected graphs. A new graph invariant is formulated. It can be used to detect isomorphism of connected graphs. The vector space of all simple cycles of the graph and their edge-disjoint unions (cycle space) and the vector space of all cutting sets of the graph and their edge-disjoint unions (cut space) are constructed in the article for finding a new graph invariant. The authors investigate the method of constructing these vector spaces: cycle space and cut space. A new estimate of the dimensions of these vector spaces of the graph is given. The obtained invariant is demonstrated on a concrete example. A counterexample is constructed to confirm the fact that the proposed invariant can be used as a necessary but not sufficient condition for graphs isomorphism. A heuristic algorithm is proposed for constructing a one-to-one correspondence between sets of vertices of isomorphic graphs.
PL
W artykule badamy istnienie izomorfizmów między grafami oraz poszukujemy niezmienników grafów spójnych. Tworzony jest nowy niezmienniczy graf. Metoda może służyć do wykrywania izomorfizmów między grafami spójnymi. W pracy użyto pojęcia przestrzeni wektorowej wszystkich prostych cykli grafu i ich sum względem rozłącznych krawędzi oraz przestrzeni wektorowej wszystkich zbiorów grafów uciętych i ich rozłącznych krawędziowo sum. Zbadano metodę konstruowania takich przestrzeni wektorowych: przestrzeni cyklicznej i przestrzeni cięcia. Podano nowe oszacowanie wymiarów tych tego typu przestrzeni wektorowych grafów. Otrzymany niezmiennik jest pokazany na konkretnym przykładzie. W pracy podano kontrprzykład, aby potwierdzić fakt, że zaproponowany niezmiennik może być użyty jako warunek konieczny, ale niewystarczający dla izomorfizmu grafów.
8
Content available On the structure of compact graphs
Nikandish R., Shaveisi F.
Opuscula Mathematica
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2017
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Vol. 37, no. 6
875--886
EN
A simple graph G is called a compact graph if G contains no isolated vertices and for each pair x, y of non-adjacent vertices of G, there is a vertex z with N(x) ∪ N(y) ⊆ N(z), where N(v) is the neighborhood of v, for every vertex v of G. In this paper, compact graphs with sufficient number of edges are studied. Also, it is proved that every regular compact graph is strongly regular. Some results about cycles in compact graphs are proved, too. Among other results, it is proved that if the ascending chain condition holds for the set of neighbors of a compact graph G, then the descending chain condition holds for the set of neighbors of G.
9
Content available remote Graphs with every path of length k in a hamiltonian cycle
Gancarzewicz G.
Czasopismo Techniczne. Nauki Podstawowe
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2014
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R. 111, z. 2-NP
45--58
EN
brak
10
Content available remote Cycles containing specified edges in a graph
Gancarzewicz G.
Czasopismo Techniczne. Nauki Podstawowe
|
2014
|
R. 111, z. 2-NP
37--43
EN
brak
11
Content available remote Pętla czy koło?
Skalski J.
Czasopismo Techniczne. Architektura
|
2011
|
R. 108, z. 4-A/2
381--384
PL
Los pomysłu i rzeczy architektonicznej w ciągu historii kołem się toczy. Cykl mody i teorię śmieci można adoptować do jego opisu. Co było - będzie, a co jest - było i kiedyś powróci. Wydaje się zatem, iż rzecz i pomysł architektoniczny wymykają się trójpodziałowi czasu, tracąc wprawdzie wartość utylitarną i fizyczną.
EN
The fate of the idea and the architectural thing within history with the circle goes on. The cycle of the fashion and the theory garbage one can adopt to his description. What will be , and what is was and once will come back. It seems therefore, that the thing and the architectural idea escape to the trisection of the time, losing indeed the value utilitarian and physical.
12
Content available Dominating sets and domination polynomials of certain graphs, II
Alikhani S., Yee-hock P.
Opuscula Mathematica
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2010
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Vol. 30, no. 1
37-51
EN
The domination polynomial of a graph G of order n is the polynomial [formula] where d(G, i) is the number of dominating sets of G of size i, and ϒ (G) is the domination number of G. In this paper, we obtain some properties of the coefficients of D(G, x). Also, by study of the dominating sets and the domination polynomials of specific graphs denoted by G'(m), we obtain a relationship between the domination polynomial of graphs containing an induced path of length at least three, and the domination polynomial of related graphs obtained by replacing the path by shorter path. As examples of graphs G' (m), we study the dominating sets and domination polynomials of cycles and generalized theta graphs. Finally, we show that, if n ≡ 0, 2(mod 3) and D(G, x) = D(Cn, x), then G = Cn.
13
Content available remote Siłownia hybrydowa z silnikiem parogazowym z wtryskiem pary wodnej do komory spalania i obniżonym ciśnieniem wylotowym - porównanie z obiegami H2/O2
Chodkiewicz R.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2009
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nr 136
21-32
PL
W pracy przedstawiono wyniki obliczeń obiegu silnika parogazowego z wtryskiem pary wodnej do komory spalania i obniżonym ciśnieniem wylotowym. Obliczenia dotyczyły siłowni dwupaliwowej wykorzystującej technologię węglową (zmodyfikowana siłownia węglowa Łagisza) oraz silnik parogazowy opalany gazem ziemnym
EN
In the paper are presented results of computation a new steam-gas engine cycle with steam injection into the combustor and lowered outlet pressure. The calculations are concerned of dual-fuel power plant which uses coal technology (based on the modified Łagisza power plant) and steam-gas engine fueled with natural gas.
14
Content available remote Planar packing of cycles and unicyclic graphs
Gorlich A.
Demonstratio Mathematica
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2009
|
Vol. 42, nr 4
673-679
EN
We say that a graph G is packable into a complete graph Kn if there are two edge-disjoint subgraphs of Kn both isomorphic to G. It is equivalent to the existence of a permutation a of a vertex set in G such that if an edge xy belongs to E(G), then a(x)cr(y) does not belong to E(G). In 2002 Garcia et al. have shown that a non-star tree T is planary packable into a complete graph Kn. In this paper we show that for any packable cycle Cn except of the case n = 5 and n=7 there exists a planar packing into Kn. We also generalize this result to certain classes of unicyclic graphs.
15
Czym jest czas w środowisku naturalnym
Włodek J. J.
LAB Laboratoria, Aparatura, Badania
|
2008
|
R. 13, nr 6
26-28
PL
Czas jest niezwykłym niematerialnym tworem umysłu człowieka. Istota czasu jest określona w sposób zwięzły, lecz komunikatywny listą opisową, której składnikami jest siedem własności przedmiotowych: chwila, cykl, interwał czasowy, okres, upływ czasu, tempo upływu czasu, teraźniejszość oraz cztery własności funkcjonalne: indeks temporalny, przeszłość, przyszłość i równoczesność zdarzeń. Każda z tych własności jest zdefiniowana.
16
Content available remote Cykl torowy w energetyce jądrowej
Chwaszczewski S.
Spektrum
|
2007
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nr 1-2
XXXIV-XXXVI
17
Content available Algebraic construction of a coboundary of a given cycle
Mazur M., Szybowski J.
Opuscula Mathematica
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2007
|
Vol. 27, no. 2
291-300
EN
We present an algebraic construction of the coboundary of a given cycle as a simpler alternative to the geometric one introduced in [4, 5].
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