Wyniki wyszukiwania - BazTech

1

Multi-fragmental and multi-phase availability models of the safety-critical I&C systems with two-cascade redundancy

Kharchenko Vyacheslav, Ponochovnyi Yuriy, Babeshko Ievgen

International Journal of Electronics and Telecommunications

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2024

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Vol. 70, No. 1

211--218

EN

Traditional availability, reliability, and safety models face the dimension problem due to a huge number of components in modern systems, motivating further research in this field. This paper focuses on multi-fragmental and multiphase models for availability and functional safety assessment of the information and control (I&C) systems with two-cascade redundancy considering design faults manifestation during operation. The methodology of the research is based on Markov and semi-Markov chains with the utilization of multi-phase modeling. Several multi-phase models are developed and investigated considering different conditions of operation and failures caused by version faults. The case study of the research is based on the analysis of safety-critical nuclear power plant I&C systems such as the reactor trip systems developed using the programmable platform RadICS.

2

Evaluation of the Efficacy of Effective Microorganisms in the Reclamation of Degraded Soils

Żukowska Grażyna, Myszura-Dymek Magdalena, Durczyńska Zofia, Bik-Małodzińska Marta, Roszkowski Szymon

Advances in Science and Technology. Research Journal

|

2024

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Vol. 18, no 1

360--369

EN

The article assesses the suitability of effective microorganisms (EM) for the reclamation of degraded soils. The aim of the research was to determine the reclamation effectiveness of the use of EM against the background of mineral wool used together with sewage sludge or mineral fertilization with nitrogen, phosphorus, potassium (NPK) on soils degraded as a result of sulfur extraction. The effectiveness of reclamation was assessed on the basis of changes in the total organic carbon (TOC) content and the properties of humic compounds. The obtained results showed that the use of effective microorganisms in relation to mineral wool and wool used in combination with sewage sludge or NPK causes significant changes in the content and quality of soil organic matter. The observed decrease in the content of TOC, humins and an increase in the share of carbon of labile fractions and free and loosely bound with silicate-free (R2O3) and calcium (Ca) humus forms indicate, that in the soils in which effective microorganisms were used, mineralization processes dominated in the transformation of soil organic matter. The humification process resulted in more durable humic compounds with a higher content of humic acids and humic acids to fulvic acids ratio (C-HA:C-FA). Supplementing commonly used materials in soil reclamation with the introduction of effective microorganisms is a promising technology. Further research is necessary to determine the composition of these biofertilisers and the optimal doses at which they should be used.

3

Using the Pulsed Eddy Current Techniques for Monitoring the Aircraft Structure Condition

Lysenko Iuliia, Kuts Yurii, Uchanin Valentyn, Protasov Anatoliy, Petryk Valentyn, Alexiev Alexander

Transactions on Aerospace Research

|

2023

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Nr 1 (270)

22--31

EN

It is known that during operation, the aircraft construction materials are exposed to significant mechanical loads and changes in temperature for a very short period of time. All this leads to various defects and damages in the aircraft assemblies and units that need to be inspected for the safe operation of the aircraft, their assemblies, and units. In some cases, the implementation of inspection or diagnostic is accompanied by the emergence of technical difficulties caused by the large size of the aircraft assemblies or units and limited access to their local places. Under such conditions, ensuring the possibility of diagnosis in hard-to-reach places of the object becomes especially important. The problem can be solved by applying wireless technologies. It allows spatial separation of the probes and the signal processing units, which simplifies the scanning of the surfaces of the large assemblies and units in hard-to-reach places. In this article, the description of the developed wireless system of eddy current inspection for aircraft structural materials is given. Experimental results of object scanning are given in the form of a distribution of the values of probe signal informative parameters (amplitude, frequency and decrement) along the object coordinates.

4

Unusual regioselectivity in [3+2] cycloaddition reactions between (E)-3-nitroacrylic acid derivatives and (Z)-C,N-diphenylimine N-oxide

Kras Jowita, Wróblewska Aneta, Kącka-Zych Agnieszka

Scientiae Radices

|

2023

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Vol. 2, Iss. 2

112-117

EN

[3+2] cycloaddition reactions of -COOMe and -CN trans-substituted nitroethenes with (Z)-C,N-diphenylimine N-oxide were tested. For the contrast to most known nitroalkene/nitrone cycloaditions, the reactions studied realized with the formation of 5-nitroisoxazolidines.

5

Wpływ metody suszenia na zawartość polifenoli ogółem, chlorofili i witaminy C w kolendrze siewnej (Coriandrum sativum L.)

Kwaśniewska-Karolak Izabela

Przemysł Spożywczy

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2023

|

T. 77, nr 1

15--18

PL

Przyprawy i zioła stanowią ważny element w diecie człowieka. Charakteryzują się wysokimi walorami smakowo-aromatycznymi oraz właściwościami leczniczymi. Zbadano wpływu metod suszenia (suszenie sublimacyjne oraz konwekcyjne) na zawartość związków aktywnych (kwasu askorbinowego, polifenoli oraz chlorofili) w kolendrze. Zakres pracy obejmował analizę ziela w trzech postaciach (świeżej, suszonej konwekcyjnie oraz sublimacyjnie) pod kątem zawartości suchej masy, zawartości barwników chlorofilowych, zawartości sumy związków polifenolowych oraz aktywności przeciwutleniającej metodą z rodnikiem DPPH. W wyniku prowadzonych analiz stwierdzono, że procesy suszenia spowodowały wzrost zawartości polifenoli w porównaniu do ziół świeżych oraz znaczne obniżenie dawki powodującej 50% redukcję rodnika DPPH w porównaniu do świeżego surowca. Największą zawartością barwnika chlorofilowego i kwasu askorbinowego charakteryzowała się świeża kolendra. Suszenie ziół spowodowało znaczny spadek zawartości barwników i witaminy C, przy czym większe ubytki zaobserwowano w przypadku ziół suszonych metodą konwekcyjną w porównaniu z sublimacyjną. Tym samym stwierdzono, że bardziej korzystną metodą utrwalania ziół jest metoda suszenia sublimacyjnego.

EN

Spices and herbs are important elements in the human diet. They are characterized by strong, taste aromatic values and therapeutic properties. The aim of the study was to investigate the effect of drying methods (freeze-drying and convection drying) on the content of active compounds such as ascorbic acid, polyphenols, and chlorophylls in coriander herb. The scope of the work included the analysis of herbs in three forms (fresh, dried, and freeze-dried) in terms of dry matter content, chlorophyll dyes content, total polyphenolic compounds content and antioxidant activity using the DPPH radical method. As a result of the conducted analyzes, it was found that applied drying processes caused an increase in the content of polyphenols compared to fresh herbs and a significant reduction in the dose resulting in a 50% reduction of the DPPH radical compared to the fresh raw material. Fresh coriander herb was characterized by the highest content of chlorophyll dye and ascorbic acid. Drying of herbs resulted in a significant decrease in the content of dyes and vitamin C, with greater losses observed in the case of herbs dried using the convection method. Thus, it was found that the freeze-drying is a more advantageous method of herb preservation.

6

System zwalniania wątków VRTS jako alternatywa dla RTOS

Świtalski Emilian, Górecki Krzysztof

Przegląd Elektrotechniczny

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2023

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R. 99, nr 9

258--261

PL

Artykuł opisuje implementację systemu zwalniania wątków VRTS, dostępnego na platformie GitHub pod adresem https://github.com/Xaeian/VRTS. Jest to alternatywa dla systemów czasu rzeczywistego RTOS w systemach wbudowanych. Przedstawiono różne koncepcje programowania mikrokontrolerów, zwracając uwagę na różnice między nimi. Omówiono funkcjonalności biblioteki VRTS, przedstawiając jej wykorzystanie w układzie zasilającym elektrolizer alkaliczny.

EN

The article presents VRTS - cooperative multitasking, searchable on GitHub at https://github.com/Xaeian/VRTS. It is an alternative to real-time operating systems (RTOS) in embedded systems. Various concepts of programming microcontrollers were presented, paying attention to the differences between them. The functionalities of the VRTS library were discussed, presenting its use in the supply system of alkaline electrolyzer.

7

Design and optimization of the construction of a mobile disinfection chamber for small communication devices and small objects

Galík Jan, Varecha Daniel, Drbúl Mário, Madaj Rudolf, Konstantová Viera

Production Engineering Archives

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2023

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Vol. 29, Iss. 2

201-215

EN

This manuscript aims to familiarise readers with the development of a device for the construction of a mobile disinfection chamber for small communication devices and small objects. The conceptual design and the material of the new device play essential roles in the design process of a new device. The manuscript presents concepts based primarily on previous experience and different perspectives. The concept design is created in the 3D modelling program CREO Parametric 8.0. A multi-criteria team evaluation determined the most suitable version of the idea. For dimensioning and shape adaptation of the device was used EinScan SP device (3D scanning method). The article's aim was also to establish a suitable way of producing a prototype using tribological research in available production methods and materials within rapid prototyping. Using the ALICONA Infinite Focus G5 device, experimentally investigated the parameters characterising the surface of the parts. The end of the manuscript focused on the mechanical structure and subjecting them to FEM analysis in the program ANSYS Workbench. The design of the concept disinfection device was also for extreme cases of use. Within this issue was optimising shapes, wall thicknesses, reinforcement design and other necessary modifications using the FEM analysis. From the results, the most suitable material to produce a more significant number of parts may not be the most suitable material to create prototype devices. Tools such as 3D scanning, rapid prototyping, and FEM analysis can "significantly" help reduce mistakes before testing the device.

8

Efficient solidification of Pb2+ by activated tungsten tailings and cement

Cheng Hao, Kuang Jingzhong, Zhu Luping, Yuan Weiquan, Huang Zheyu, Yang Yiqiang

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 2

art. no. 162618

EN

The preparation of cementing admixture from tailings and co-solidification of Pb2+ with cement is a green way to realize the resource utilization of tailings and treatment of the lead-containing wastewater. In this paper, the tungsten tailings were activated in different ways, and the mechanical properties of the tungsten tailings-cement solidified body with different activation systems and the solidification behavior of Pb2+ were studied. The phase and microstructure of the hydrated product were characterized by XRD, FT-IR, SEM and EDS. The results showed that the curing effect of Pb2+ was obviously different of different activation systems, and the curing effect of the solidified body of the ternary composite activation system (TCAS) was the best, second only to the pure cement system (PCS). Different activation methods have a significant impact on the mechanical properties of the solidified body. With the increase of the Pb2+ content, the compressive strength of the solidified body gradually decreased, the Pb2+ leaching concentration gradually increased; with the extension of the curing age, the compressive strength gradually increased, and the Pb2+ leaching concentration gradually decreased. In particular, the compressive strength of the 28d solidified body was 31.43 MPa and the leaching concentration of Pb2+ was only 0.38 mg/L when the Pb2+ content was 5%. The phase, microstructure and EDS results of the hydration products showed that Pb2+ was mainly solidified in the C-S-H gel.

9

Expectations for renewable energy, and its impacts on quality of life in European Union countries

Rosak-Szyrocka Joanna, Allahham Almuhannad, Żywiołek Justyna, Turi Jamshid Ali, Das Anupam

Management Systems in Production Engineering

|

2023

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nr 2 (31)

128--137

EN

The primary goals of the study are to present a qualitative examination of household awareness of renewable energy sources and to ascertain their requirements, as well as their expectations for an improvement in quality of life as a consequence of using renewable energy to reduce greenhouse gas emissions and air pollution while improving public health. There are no empirical studies examining the level of household awareness of renewable energy in EU countries, so this gap is also considered a further area of empirical research. Seven European nations were selected for the study: the Czech Republic, Slovenia, France, Portugal, Spain, Austria, and Germany. The survey was conducted from April 2021 to June 2022 with over 17030 respondents. Additionally, it was given a statistical analysis by using the C-Pearson coefficient. Results of our study showed that households’ awareness is low and they also expect that they will not pay more for tourist services that use renewable energy sources. Moreover, results showed that when renewable energy sources are used, in households’ opinions, levels of CO2 will decrease and that this will have a favorable effect on the environment, but they still think that this will have a detrimental influence on their health.

10

Potato with Colored Flesh Valuable and Attractive to the Consumer

Zarzecka Krystyna, Ginter Agnieszka, Gugała Marek, Mystkowska Iwona, Rymuza Katarzyna

Journal of Ecological Engineering

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2023

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Vol. 24, nr 6

166--172

EN

The purpose of this paper was to determine the vitamin C content and the selected consumption features (tastiness and cooking type) in edible potato tubers with colored flesh. The research material consisted of tubers of eight edible potato cultivars collected from a field experiment conducted in 2021 and 2022 at the Agricultural Experimental Station in Zawady of Siedlce University of Natural Sciences and Humanities (52°03’N; 22°33’E). The following cultivars were grown: two cultivars with red flesh – Rote Emma and Herbie 26, five cultivars with purple flesh – Blaue Annelise, Provita, Salad Blue, Vitelotte and Bora Valley, as well as one traditional cultivar, light yellow fleshed – Eurostar. The cultivar features of the potato tubers significantly modified the content of vitamin C and they determined cooking properties of the potato. The cultivars with red and purple flesh accumulated more vitamin C than the traditional cultivar. The cultivar Rote Emma and Salad Blue had the best tastiness, while the cultivar Herbie 26 and Bora Valley proved to be the least tasty. The red and purple-fleshed cultivars were dominated by the salad cooking type A and they differed significantly from the traditional cultivar Eurostar. Potato tubers with colored flesh are a valuable and attractive offer to the consumer.

11

Analiza porównawcza języków C oraz Python na podstawie czasu wykonania aplikacji realizujących wybrane algorytmy

Rysak Paweł

Journal of Computer Sciences Institute

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2023

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Vol. 26

93--99

PL

Artykuł dotyczy analizy porównawczej szybkości wykonywania kodu przez język C oraz Python. Jej podstawowym celem nie było szukanie prostej odpowiedzi na pytanie, który z języków będzie wydajniejszy, tylko jaka jest skala różnic w wydajności tych języków. W celu określenia wydajności języka kompilowanego oraz skryptowego dokonano zestawienia języków na przykładzie następujących algorytmów: algorytm rozwiązujący problem wieży Hanoi, algorytm kodowania Huffmana oraz algorytm zamiany liczb na tekst. Każdy z wymienionych algorytmów został zaimplementowany w obydwu językach. Następnie dokonano pomiaru czasu realizacji programów, którego wyniki pozwoliły na określenie skali różnic w szybkości ich wykonania. W języku C aplikacje wykonywałysię od 6 do 188 razy szybciej niż aplikacje w języku Python

EN

The article deals with a comparative analysis of the speed of code execution written in the C language and Python. In order to determine whether a scripting language can match the performance of a compiled language, a comparison of the languages was made using the following algorithms: the algorithm for solving the Hanoi tower problem, the Huffman encoding algorithm and the algorithm for converting numbers into text. Each of the listed algorithms was implemented in both languages. Then the execution time of the programs was measured and the results were obtained, which prove that the C language achieves better performance in most cases.

12

Node Localization based on Anchor Placement using Fuzzy C-Means in a Wireless Sensor Network

Irid Sidi Mohammed Hadj, Hadjila Mourad, Hachemi Mohammed Hicham, Souiki Sihem, Mosteghanemi Reda, Mostefai Chaima

International Journal of Electronics and Telecommunications

|

2023

|

Vol. 69, No. 1

99--104

EN

Localization is one of the oldest mathematical and technical problems that have been at the forefront of research and development for decades. In a wireless sensor network (WSN), nodes are not able to recognize their position. To solve this problem, studies have been done on algorithms to achieve accurate estimation of nodes in WSNs. In this paper, we present an improvement of a localization algorithm namely Gaussian mixture semi-definite programming (GM-SDP-2). GMSDP is based on the received signal strength (RSS) to achieve a maximum likelihood location estimator. The improvement lies in the placement of anchors through the Fuzzy C-Means clustering method where the cluster centers represent the anchors’ positions. The simulation of the algorithm is done in Matlab and is based on two evaluation metrics, namely normalized root-mean-squared error (RMSE) and cumulative distribution function (CDF). Simulation results show that our improved algorithm achieves better performance compared to those using a predetermined placement of anchors.

13

Effect of 1-methylcyclopropene and ULO conditions on bioactive composition and organoleptic properties of apples during storage

Wichrowska Dorota

Infrastruktura i Ekologia Terenów Wiejskich

|

2023

|

nr I/1

221--239

EN

The aim of this study was to analyze the effect of the use of an agent inhibiting ethylene release - 1-Methylcyclopropene in the storage of selected apple varieties ‘Szampion’, ‘Gloster’, ‘Elstar’, ‘Ligol’, ‘Idared’, ‘Jonagold’, and ‘Honeygold’ originating from orchards of the Fruit Plant in Wtelno and stored in chambers with a controlled atmosphere. Laboratory analyzes were performed immediately after harvest and after 6 months of storage in chambers under ULO conditions (<2% O2, <2%CO2) at a temperature of 1.5-2.0°C and relative air humidity of 95-96%. Fruits treated with 1-MCP were characterized by significantly lower losses of bioactive compounds, especially vitamin C, compared to untreated apples. The contents of total polyphenols and chlorogenic acid remained at a similar level as after harvest in untreated apple samples. After the storage period, the ‘Szampion’ variety contained significantly the most polyphenolic compounds, and the least - the ‘Honeygold’ variety, where the highest decrease was also recorded during storage (26.7%) in fruits not treated with 1-MCP. After storage, the ‘Ligol’ and ‘Elstar’ cultivars had the significantly highest content of chlorogenic acid. The highest losses of chlorogenic acid during apple storage (32.4%) were observed in the ‘Honeygold’ variety. The lowest loss of ascorbic acid during apple storage ((34.9%) was observed in the ‘Idared’ variety, and the highest loss in the ‘Honeygold’ variety (66.8%).

14

Evaluation of Insulation against Contact Heat, Radiant Heat and Sensory Comfort of Basalt Fabric-Based Composites with Parylene C Coating

Tokarska Magdalena, Miśkiewicz Pamela, Puszkarz Adam K., Nosal Andrzej

Fibres & Textiles in Eastern Europe

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2023

|

Vol. 31, no. 5

99--108

EN

The article concerns research on using Parylene C coating on basalt fabric-based composites with potential use in protective clothing to improve their insulation against contact heat and radiant heat, as well as the sensory comfort of the user. The outcomes of the contact heat method showed that applying Parylene C coating improved the thermal insulation of all tested composites. Two of them achieved the first efficiency level of protection. The results of the radiant heat method presented that using the Parylene C coating did not cause changes in the thermal insulation against heat radiation of all tested materials; the radiant heat transfer index reached values in the range of 12.4 - 12.9 s. X-ray tomography (micro-CT) allowed for identifying breaks/snaps in basalt fibers irritating the user’s skin in direct contact with the composite. Micro-CT results also showed that using Parylene C coating eliminated the effect of skin irritation and increased the usability of basalt fabrics in clothing.

15

Nowa wysokochromowa stal martenzytyczna na elementy kotłów energetycznych do pracy w warunkach pełzania powyżej 600oC

Purzyńska Hanna, Dobrzański Janusz, Zieliński Adam

Energetyka

|

2023

|

nr 11

665--666

PL

Zaproponowano nową stal wysokochromową na wężownice wyższych stopni przegrzewacza pary o odporności na pełzanie porównywalnej ze austenityczną stalą TP347HFG oraz o pozostałych właściwościach mechanicznych odpowiadających stali P92.

EN

A new high-chromium steel was proposed for the coils of higher stages of the steam superheater, with creep resistance comparable to the austenitic TP347HFG steel and other mechanical properties corresponding to P92 steel.

16

Bezpieczniki topikowe instalacyjne małogabarytowe typu D0

Trzebiatowski Konrad

Elektro Info

|

2023

|

nr 5

50--54

PL

Celem niniejszego artykułu jest przedstawienie systemu bezpieczników topikowych małogabarytowych DO przeznaczonych do obsługi (w zakresie wymiany po ich przepaleniu) przez osoby niewykwalifikowane/niepoinstruowane. Opisano dokładnie wszystkie części składowe: gniazdo bezpiecznikowe, wkładkę topikową, wstawkę ograniczającą, główkę bezpiecznikową i wstawkę redukcyjną. Podano ich parametry elektryczne oraz przywołano normę PN-HD 60269-3, według której zostały zaprojektowane i wykonane. Przedstawiono również wkładki topikowe cylindryczne, ich parametry elektryczne oraz jako wyposażenie dodatkowe – rozłącznik z bezpiecznikami na szyny prądowe i rozłącznik bezpiecznikowy do wkładek topikowych cylindrycznych.

17

Handling dimensionality of ambiguity using ensemble classification in social networks to detect multi-label sentiment polarity

Sonawane Sudarshan S., Kolhe Satish R.

Computer Assisted Methods in Engineering and Science

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2023

|

Vol. 30, no. 1

7--26

EN

With ever-increasing demand, social media platforms are rapidly developing to enable users to express and share their opinions on a variety of topics. Twitter is one such social media site. This platform enables a comprehensive view of the social media target setting, which may include products, social events, political scenarios, and administrative resolutions. The accessible tweets expressing the target audience’s perspective are frequently impacted by ambiguity caused by natural language processing (NLP) limitations. By classifying tweets according to their sentiment polarity, we can determine whether they express a good or negative point of view, a neutral opinion, or an input tweet that is irrelevant to the sentiment polarity context. Categorizing tweets according to their sentiment can assist future activities within the target domain in constructively evaluating the sentiment polarity and enabling improved decision-making based on the observed sentiment polarity. In this study, tweets that were previously categorized with one of the sentiment polarities were used to conduct predictive analytics of the new tweet to determine its sentiment polarity. The ambiguity of the tweets corpus utilized in the training phase is a critical limitation of the sentiment categorization procedure. While several recent models proposed sentiment classification algorithms, they confined themselves to two labels: positive and negative opinion, oblivious to the plague of ambiguity in the training corpus. In this regard, a novel multi-label classification of sentiment polarity called handling dimensionality of ambiguity using ensemble classification (HAD-EC) method, which diffuses ambiguity and thus minimizes false alerts, is proposed. The experimental assessment validates the HAD-EC approach by comparing the suggested model’s performance to other two existing models.

18

Strength analysis of eccentrically loaded thin-walled steel lipped C-profile columns

Czechowski Leszek, Kotełko Maria, Jankowski Jacek, Ungureanu Viorel, Sanduly Annabella

Archives of Civil Engineering

|

2023

|

Vol. 69, nr 3

301--316

EN

The work includes the results of numerical, analytical-numerical and experimental study into the influence of load eccentricities with regard to major axis on post-buckling behaviour and load-carrying capacity of thin-walled cold-formed steel lipped channel section columns. The study was solved by using the finite element method (code Ansys) with taking into consideration a full material characteristics in logarithmic strain system and geometric nonlinearities. The analytical-numerical solution was based on Koiter’s theory with an application of finite difference method (FDM). Some chosen results of numerical simulations have been compared to experimental results. The deformations of columns were registered by means of Digital Image Correlation Aramis System (DICAS) to observe the maps and the magnitude of displacements for adequate point of a load. The analyses showed that the decrease in maximum load in a dependency on the eccentricity value can be even 3 times minor in a comparison to the load-carrying capacity of axially loaded column.

PL

Praca dotyczy analiz numerycznych, numeryczno-analitycznych i eksperymentalnych wpływu obciążeń mimośrodowych względem osi centralnej Imax na pokrytyczne zachowanie i nośność cienkościennych zimno formowanych stalowych słupów o przekroju otwartym z żebrami końcowymi w pasach. Problem został rozwiązany stosując metodę elementów skończonych (program Ansys) z uwzględnieniem pełnych charakterystyk materiałowych w układnie logarytmicznym oraz nieliniowości geometrycznych. Rozwiązanie analityczno-numeryczne zostało oparte o teorię Koitera z zastosowaniem metody różnic skończonych. Wybrane wyniki symulacji zostały porównane z wynikami empirycznymi. Deformacje słupów podczas wykonywania badań doświadczalnych były rejestrowane optyczną metodą cyfrowej korelacji obrazów za pomocą systemu Aramis w celu określenia map deformacji i wielkości przemieszczeń punktów dla określonego obciążenia. Wyniki analizy pokazały, iż spadek w maksymalnych siłach w zależności od przesunięcia siły ściskającej względem osi centralnej słupa, może być nawet trzykrotny w odniesieniu do nośności ceowników ściskanych osiowo.

19

Influence of Composite Lay-Up on the Stability of Channel-Section Profiles Weakened by Cut-Outs – A Numerical Investigation

Falkowicz Katarzyna, Valvo Paolo Sebastiano

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 1

108--115

EN

This paper presents a numerical study on the stability of composite channel-section profiles weakened by cut-outs. Profiles were made from carbon fibre-reinforced polymer (CFRP) laminates and subjected to compression load. Numerical analysis carried out in the Abaqus software allowed us to determine the value of the buckling load and the corresponding buckling form. Four different laminate lay-ups were chosen to study their effects on the buckling behaviour of the profiles. Obtained results help identify the best laminate lay-up to get the highest critical buckling load for perforated columns. The performed analysis shows that [45/-45/90/0]s and [90/-45/45/0]s composite lay-ups have the greatest impact on the buckling load. Moreover, the introduced perforation caused a change in the buckling form and a decrease in the critical load value.

20

Porosity prediction using Fuzzy SVR and FCM SVR from well logs of an oil field in south of Iran

Moosavi Nastaran, Bagheri Majid, Nabi-Bidhendi Majid, Heidari Reza

Acta Geophysica

|

2023

|

Vol. 71, no. 2

769--782

EN

Identification of petrophysical parameters including porosity plays an important role to evaluate hydrocarbon reservoirs. A precise prediction of porosity in oil and gas reservoirs may prevent lots of costs before drilling operations. Porosity obtained from core analysis in laboratory is the most reliable one, while they are very expensive and not always accessible. Inappropriate or missing data in under-survey locations are a key challenge for reservoir engineers. In this paper, support vector regression (SVR) is used to estimate porosity in one of the oil fields in south of Iran. SVR creates models due to structural risk minimization methods which help us to produce models with better generalization and less risk of overfitting. Definitely, measured data are always contaminated with noise. One of the common methods to reduce noise and outliers in data is to process them before using them to train the algorithm; during processing, outliers and some noisy data can be suppressed from data, while it is not always easy to distinguish real data from noise. In this paper, we modified SVR to Fuzzy SVR and Fuzzy C Means (FCM) SVR, which are used to decrease effect of noise on model, and then by adding artificial noise including random noise and outliers to data we investigated how these two methods respond to presence of noise. The results show the presence of noise and outliers in data can alter the center locations and distribution of data points in clusters in FCM SVR. Similarly, it can change the variance of Gaussian membership function we used for Fuzzy SVR, but overall, the results show Fuzzy SVR model is notably more robust against noise compared to FCM SVR. Correlation coefficient (CC) calculated between model and core data decreased from 78 to 67% after noise added to data in FCM SVR model, however, calculated CC for Fuzzy SVR remained almost steady altering from 87 to 86%. Subsequently, calculated root mean square error (RMSE) between models and core data increased from 0.0376 to 0.03827 for Fuzzy SVR, while RMSE jumped from 0.0448 to 0.0517 for FCM SVR.