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1

Effect of Karanja biodiesel blends on the characteristics of diesel engine

Yadav Sandeep, Kumar Amit, Chaudhary Abhilasha

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 115

249--264

EN

Extensive research is being conducted to create and use a wide range of alternative fuels to accommodate the world's growing energy needs. The objective of this experimental investigation was to analyze the effects of Karanja biodiesel blends on the performance, combustion, and emission characteristics of a compression ignition (CI) engine vis-a-vis neat diesel. Important physical parameters of Karanja oil were examined experimentally after transesterification and determined to be within acceptable limits. BTE of Karanja biodiesel blends was about 3-8% lower than diesel. For Karanja biodiesel blends, BSFC was about 2-9% higher than diesel but exhaust gas temperature and volumetric efficiency were lower. Emissions characteristics such as nitrogen oxides, hydrocarbons, and carbon monoxide were also analyzed for various tested fuels. Karanja biodiesel blends resulted in lesser CO and HC formation. Nonetheless, NOx emissions were around 10% greater than diesel. Peak cylinder pressure, heat release rate, and maximum rate of pressure rise versus crank angle were among the combustion characteristics parameters considered in this study. Combustion analysis revealed that for Karanja biodiesel blends heat release rate and peak cylinder pressure were lower than for neat diesel. Findings indicate that Karanja biodiesel can be considered a viable diesel engine fuel.

2

Cost efficiency of administrative service in public higher education in Poland

Brzezicki Łukasz, Łącka Irena

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

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2022

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z. 156

81--98

EN

Purpose: The aim of the study is to determine changes in the cost efficiency of the administration of public higher education in Poland. Design/methodology/approach: The biennial cost Malmquist productivity index was used to study changes in cost efficiency of 58 public higher education institutions in 2014-2016. The results were presented for 6 groups of universities, according to the Ministry of Science and Higher Education in Poland classification. Findings: The research shows that out of 6 groups of institutions accepted for the study, 2 achieved an increase and 1 a decrease in the Malmquist cost index in both study periods. Changes in the Malmquist cost index in the analyzed period are small as the index ranged from 0.98 to 1.06. Both component overall efficiency change and cost-technical change contributed to the change in the Malmquist index level. Research limitations/implications: The main limitation of the study are the analysis of changes in cost efficiency only. Additionally, only public universities supervised by the ministry responsible for higher education were studied. Future research should include changes in allocative efficiency using the Malmquist index. In addition, a larger research sample should be considered, taking into account other public universities, including medical, arts, etc., and non-public universities. Practical implications: The considerations presented are relevant to public university authorities. The article indicates the need to assess cost effectiveness in evaluating the functioning of a higher education institution. This belongs to the responsibilities of management control in terms of effectiveness and efficiency of HEIs and spending of public funds. Information on the variation of cost efficiency between HEIs, assigned to 6 groups, may become a stimulus to conduct an assessment of this economic category in a given unit and strive to improve it. Originality/value: The added value of the article is the use for the first time of the cost Malmquist index to examine higher education. Also, the use of a modified version of the cost Malmquist index to estimate efficiency assuming variable returns-to-scale.

3

Sortowniki wibracyjne wiszące. Część 2

Reczulski Mariusz

Przegląd Papierniczy

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2022

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R. 78, nr 2

90--93

PL

Kontynuując prezentacje sortowników wibracyjnych wiszących, światowych producentów maszyn i urządzeń branży celulozowo-papierniczej [5], opisano wiele ciekawych rozwiązań pozwalających wydłużyć okres eksploatacji sortowników. Dotyczy to głównie sposobu samooczyszczania sit, zespołu napędowego sortowników oraz konstrukcji kosza sitowego i ramy nośnej. Nowoczesne rozwiązania sortowników wibracyjnych wiszących zapewniają odpowiednią amplitudę i częstotliwość pracy sit na całej ich powierzchni, uzyskując lepszą efektywność sortowania materiału i większą wydajność urządzeń.

4

The Efficiency of Health Systems in Response to the Covid-19 Pandemic: Evidence from the EU Countries

Rađenović Tamara, Radivojević Vladimir, Krstić Bojan, Stanišić Tanja, Živković Snežana

Problemy Ekorozwoju

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2022

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Vol. 17, nr 1

7--15

EN

The COVID-19 pandemic has revealed the insufficient capacities and capabilities of countries around the world to deal with global infectious diseases and stressed the need to improve the international health security framework. An efficient and comprehensive health system that is able to cope with public health emergencies is an essential prerequisite for strengthening health security. The paper analyzes the efficiency of health systems in the European Union (EU) countries and their responsiveness to the COVID-19 pandemic. The research covers 27 EU countries and it is based on the secondary data contained in the 2019 Global Health Security Index Report. The aim of the paper is to identify key determinants for improving the efficiency of health systems in the EU, as well as to examine the interdependence between health expenditures and the efficiency of health system in this sample of countries. The research is conducted through descriptive statistics and correlation and regression analysis. The conclusions can be useful for the EU policy makers in formulating a strategy to improve the efficiency of Member States’ health systems and preparedness for possible new pandemics.

PL

Pandemia COVID-19 ujawniła niewystarczające zasoby krajów na całym świecie do radzenia sobie z globalnymi chorobami zakaźnymi i podkreśliła potrzebę poprawy międzynarodowych ram bezpieczeństwa zdrowotnego. Wydajny i kompleksowy system opieki zdrowotnej, który jest w stanie poradzić sobie z sytuacjami kryzysowymi dotyczącymi zdrowia publicznego, jest niezbędnym warunkiem wzmocnienia bezpieczeństwa zdrowotnego. Artykuł analizuje efektywność systemów opieki zdrowotnej w krajach Unii Europejskiej (UE) i ich reakcję na pandemię COVID-19. Badanie obejmuje 27 krajów UE i opiera się na danych wtórnych zawartych w raporcie Global Health Security Index 2019. Celem artykułu jest identyfikacja kluczowych determinant poprawy efektywności systemów ochrony zdrowia w UE oraz zbadanie współzależności między wydatkami na zdrowie a efektywnością systemu ochrony zdrowia w tej grupie krajów. Badania uwzględniają statystyki opisowe oraz analizę korelacji i regresji. Wnioski mogą być przydatne dla decydentów UE przy formułowaniu strategii poprawy efektywności systemów opieki zdrowotnej państw członkowskich oraz gotowości na ewentualne nowe pandemie.

5

Peculiarities of assessing the possibilities of increasing the yield of biofuels from agricultural crops on the example of Ukraine

Pryshliak Natalia, Sakhno Andrii, Tokarchuk Dina, Shevchuk Hanna

Polityka Energetyczna

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2022

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T. 25, z. 1

155--174

EN

The development of the modern economic system is becoming increasingly dependent on the sufficient provision of quality energy resources due to the intensification and transformation of the mechanization and automation of all industries. The growth of the energy needs of society is parallel to the awareness of the need to ensure the environmentally friendly development of society. There are a number of reasons for the search for new energy sources, including the limited reserves of traditional sources, dependence on oil-exporting countries, the greenhouse effect due to the entry of carbon dioxide into the atmosphere and air pollution by harmful gases. The biofuel sector offers the potential for both the development of national agriculture and for increasing its energy independence. Global trends in the rapid development of bioenergy in combination with the systemic crisis of the energy sector in Ukraine have necessitated a detailed study on the possibility of increasing the yield of biofuels from crops. The economic and mathematical modeling of the possibility of increasing the yield of bioethanol and vegetable oil from agricultural crops has been carried out. An economic optimization model has been formed, which made it possible to study an increase in the yield of bioethanol from sugar-containing and starch-containing crops and vegetable oil from oil crops from 1 ton per 1 hectare of area. Also, an assessment of the lost yield for the investigated crops has been carried out using the method of analysis of the functioning environment (Farrell’s method).

PL

Rozwój nowoczesnego systemu gospodarczego staje się coraz bardziej uzależniony od zapewnienia wystarczających zasobów energetycznych wysokiej jakości w związku z intensyfikacją i transformacją mechanizacji i automatyzacji wszystkich gałęzi przemysłu. Wzrost potrzeb energetycznych społeczeństwa idzie w parze ze świadomością konieczności zapewnienia przyjaznego środowisku rozwoju. Powodów poszukiwania nowych źródeł energii jest wiele, m.in. ograniczone zasoby źródeł tradycyjnych, uzależnienie od krajów-eksporterów ropy naftowej, efekt cieplarniany spowodowany emisją dwutlenku węgla do atmosfery, a także zanieczyszczenie powietrza szkodliwymi gazami. Sektor biopaliw oferuje potencjał zarówno dla rozwoju krajowego rolnictwa, jak i zwiększenia niezależności energetycznej kraju. Światowe trendy w szybkim rozwoju bioenergii w połączeniu z systemowym kryzysem sektora energetycznego w Ukrainie wymusiły konieczność szczegółowego zbadania możliwości zwiększenia wydajności biopaliw z upraw. Przeprowadzono modelowanie ekonomiczne i matematyczne, w którym zbadano możliwości zwiększenia wydajności bioetanolu i oleju roślinnego z upraw rolniczych. Powstał model optymalizacji ekonomicznej, który umożliwił zbadanie wzrostu uzysku bioetanolu z upraw cukrowych i skrobiowych oraz oleju roślinnego z roślin oleistych z 1 tony na 1 ha powierzchni.

6

Tendencje rozwojowe w działalności inżynierskiej na przełomie wieków

Styp-Rekowski Michał

Obróbka Metalu

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2022

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nr 2

22--30

PL

W artykule przedstawiono dwie charakterystyczne dla początków XXI wieku tendencje, jakie obserwuje się przemyśle. Pierwsza z nich to zasada projektowania i wytwarzania maszyn dla ściśle określonych warunków i rodzaju ich pracy. Korzyści z jej stosowania są zarówno w kategoriach technicznych jak i ekonomicznych. Druga opisana tendencja to szersze niż dotąd uwzględnienie pro-ekologicznych aspektów produkcji. W tym przypadku obserwuje się korzyści przede wszystkim w kategoriach ekologicznych, lecz także i ekonomicznych. Przedstawiono przykład realizacji takiego postępowania, który potwierdził poczynione spostrzeżenia.

EN

In the paper two trends in industry that are characteristic of the 21st century beginning were presented. The first is the principle of designing and manufacturing machines for precisely defined conditions and the conditions of their work. Their advantages are both: technical and economic. The second trend described is to take more account of environmental aspects of production than hitherto. There are above all environmental benefits, but also economic ones. An example of the implementation of such a procedure was given, which confirmed the findings made.

7

Czas jako wartość w budownictwie

Sitek Magdalena

Nowoczesne Budownictwo Inżynieryjne

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2022

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Nr 4

24--35

PL

Czas to jeden ze strategicznych aspektów w budowlanym procesie inwestycyjnym, gdyż – jak powszechnie wiadomo – czas to pieniądz. Odniesienie do czasu znajdziemy praktycznie na każdym etapie realizacji, m.in. w kontrakcie, pracach projektowych, harmonogramie robót, procesie zakupowym czy w procedurach administracyjnych. Czas tworzy ramy całego przedsięwzięcia, a jego wartość stanowi o sukcesie bądź niepowodzeniu. Terminowość realizacji inwestycji to swego rodzaju wskaźnik, który może wiele powiedzieć o produktywności, wydajności czy jakości. Budownictwo XXI w. dysponuje szeroką gamą narzędzi do walki z marnotrawstwem czasu, a rozwój nowoczesnych technologii przynosi kolejne rozwiązania.

8

Flexible Formwork Flow 4.0 - usprawnienie modelu zarządzania deskowaniami na budowie w myśl zasad Przemysłu 4.0

Majkowski Łukasz, Pasławski Jerzy

Materiały Budowlane

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2022

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nr 12

67--72

PL

W wyniku badań opisywana koncepcja 3F4 została uzupełniona o system geolokalizacji i monitoring dostępny w trybie rzeczywistym. Jednocześnie należy pamiętać, iż bieżące nakłady kosztów ulegają ciągłym zmianom i są na bieżąco aktualizowane w systemie 3F4. Dzięki wprowadzeniu metodologii Lean i/lub Agile uzyskujemy pewność, że budowa działa w sposób zapewniający stabilizację procesów budowlanych oraz możliwość dostosowania do zmian. Chociaż te dwie koncepcje wymagają podjęcia innych kroków w kierunku osiągnięcia różnych celów, jednak właściwe ich połączenie z uwzględnieniem metod klasycznych i idei Przemysłu 4.0 pozwala w efekcie osiągnąć efekt synergii - usprawnienie analizowanego procesu.

EN

As a result of studies, the concept 3F4 has been supplemented by a new geolocation system and real-time monitoring. At the same time, it should be remembered that the current cost outlays are constantly changing and are constantly updated in the 3F4 system. Thanks to the introduction of Lean and/or Agile methodologies, we can be sure that the construction works in a way that ensures the stabilization of construction processes and the possibility of adapting to the following changes. Although these two concepts require taking other steps towards achieving different goals, the proper combination of them, taking into account classic methods and the idea of Industry 4.0, allows, as a result, to achieve a synergy effect - improvement the analyzed process.

9

Analiza energetyczna wydajności stropu grzewczego na przykładzie budynku mieszkalnego w Niemczech, Polsce i Ukrainie

Dudkiewicz Edyta, Fidorów-Kaprawy Natalia

Materiały Budowlane

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2022

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nr 9

84--87

PL

Ocena wydajności systemu ogrzewania stropowego w budynku wymaga uwzględnienia temperatury zewnętrznej obliczeniowej i średniorocznej w pomieszczeniach oraz współczynników przenikania ciepła przegród. Przeanalizowano właściwości grzejne stropu DX-Therm na przykładzie budynku mieszkalnego zlokalizowanego w trzech sąsiadujących krajach europejskich. Rozwiązanie okazuje się energooszczędne i komfortowe we wszystkich mieszkaniach w Polsce i Niemczech. Poddano dyskusji możliwość dostosowania go do warunków ukraińskich. Scharakteryzowano cechy termoaktywnego stropu prefabrykowanego.

EN

The assessment of the performance of a ceiling heating system in a building requires the consideration of room, external design and average annual temperature values and building envelope heat transfer coefficients. The DX-Therm ceiling heating properties have been analysed for three neighbouring European countries using an apartment building as an example. The solution proves to be energy efficient and comfortable in all apartments in Poland and Germany. The possibility of adapting it to the Ukrainian conditions is discussed. The features of the thermoactive prefabricated ceiling are characterised.

10

The effects of information technologies on automotive supply chain and firm performance. A PLS-SEM approach

Boubker Omar

LogForum

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2022

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Vol. 18, no. 1

61--75

EN

Background: In today's context, information technology is increasingly taking a great interest for academics and practitioners. IT plays a critical role in supply chain readiness to meet market changes by lowering costs and enhancing quality. Hence, the objective of this article is to explore the effect of information technology integration (ITI) and supply chain information management (SCIM) on supply chain integration (SCI) and its association with supply chain performance (SCP) and firm performance in the automotive supply chain. Methods: The research data were collected from 177 middle and top-level managers of automotive firms installed in Morocco. The structural equation modelling under the partial least squares approach was used in testing the hypotheses and proposed model. Results: The study findings show that ITI and SCIM positively and significantly affect the level of SCI. In addition, SCI positively and significantly affects SCP and firm performance. Furthermore, SCP plays a direct and positive role in improving firm performance. Conclusions: The study results provide direction on how automotive SC managers might enhance automotive SCP and firm performance.

11

Supply chain maturity models: a comparative review

Hansali Oumaima, Elrhanimi Samah, Elabbadi Laila

LogForum

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2022

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Vol. 18, no. 4

435--450

EN

Background: Due to the high potential to gain competitive advantage in today's global market, supply chains play a critical role in the current industry. Understanding maturity and its features in the context of the supply chain can help companies achieve higher levels of performance. To assess and measure supply chains, a wide variety of supply chain maturity models have been developed to help companies analyze the existing state in the supply chain, allowing for the achievement of higher levels of maturity and providing guidance in the development of an improvement roadmap. Methods: The review spans from the early 1990s to 2021 and examines research carried out and published in the literature, including papers on conference proceedings, articles in journals, and technical reports. The previous models, stages, dimensions (areas/elements), and methods are included in this review. Research gaps are also noted, analyzed, and discussed. Results: The purpose of this study is to perform a comparative analysis of supply chain maturity models to explore the special characteristics of the studied models, which help to identify the differences and similarities between each other, and also to present the various focus areas related to the supply chain. The results show the existence of a large variety of models with a trend to the customs of models for specific area of supply chain. We also identified that most of the models have similar maturity level names and number since they are developed based on previously existing maturity models. The results of this paper are meant to serve as a reference guide for a detailed understanding of documented supply chain maturity models and help practitioners to seek better alignment in regards to supply chain maturity models characteristics. Conclusions: Supply chains play an important role in the market rivalry nowadays. Understanding maturity and its components in the context of supply chain management can help companies perform at higher levels. Despite the high number of maturity models developed in the field of supply chain, the result of this review shows that there is a need for new studies to fill the gaps in the existing work and to take into consideration the complexity faced in the management of supply chain networks.

12

Comparative study of the performance of an internal combustion engine and its emission working on conventional fuel (Diesel) and alternative fuel (Bio-CNG)

Ingawale Shrikant M., Bagi J. S., Nikam L. S.

Journal of Mechanical and Energy Engineering

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2022

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Vol. 6, No 1

67--76

EN

Currently, the world is facing problems regarding environmental pollution due to the combustion of fossil fuels. Generally, the combustion of fossil fuels takes place in the Internal Combustion engine for power or electricity generation. The combustion of fossil fuels emits greenhouse gases that lead to the greenhouse effect. The main symptom of the greenhouse effect is increased earth surface temperature. Also, the resources of fossil fuels are depleting rapidly and can take thousands of years to reproduce, so the time has come to go for lesser polluting renewable fuels. In this research, Bio-CNG is considered as an alternative fuel to conventional fuel, i.e. Diesel. The performance test on four-stroke IC Engines working on Bio-CNG and Diesel fuel is conducted simultaneously. The performance parameters such as Brake Power, Indicated Power, Thermal Efficiencies, Mechanical, Volumetric efficiency for both fuels are compared. Along with the performance, the emission is also recorded and compared. The results have shown that Bio-CNG has slightly less performance ability for similar engines working on Diesel fuel. Yet, this study also shows that Bio-CNG possesses the ability to replace the conventional fuel with some engine and exhaust system modifications. The higher calorific value (47000 kJ/kg) and lower or negligible carbon emission make it the best sustainable fuel substitute to conventional fuel, i.e. Diesel.

13

Wydajność języków C++ oraz Java na platformie Android

Wlazło Paweł, Smołka Jakub

Journal of Computer Sciences Institute

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2022

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Vol. 23

135--139

PL

W artykule przedstawiono analizę porównawczą technologii Java i C++ w kontekście wydajności na platformie Andro-id. Celem tej pracy było wskazanie wydajniejszego języka do tworzenia aplikacji mobilnych. Badania przeprowadzono na autorskich aplikacjach. Testy dotyczyły sortowania danych, wyznaczania liczb pierwszych, modyfikacji bitmapy, zapisu do bazy danych i odczytu z pliku tekstowego. Serie powtórzeń każdego testu wykonane zostały na urządzeniach marki Samsung oraz Xiaomi. Kryteria, którymi się posłużono to: czas wykonania testu, obciążenie procesora, wykorzy-stanie pamięci RAM. Wydajność wwiększości przeprowadzonych testów była na korzyść języka C++. Cechą wykazu-jącą największe różnice między badanymi technologiami był czas wykonania, gdzie C++ uzyskał 18punktów, a Java 3 punkty. Dla wykorzystania procesora wynik był taki sam, jednak różnice wartości mniejsze. Parametrem niewskazu-jącym faworyta było wykorzystanie pamięci RAM. Uzyskano 11punktów dla języka C++ i10 punktów dla Javy.

EN

The article presents a comparative analysis of Java and C ++ technologies in terms of performance on the Android plat-form. The purpose of this work was to point to a more efficient language for developing mobile applications. The study was carried out on custom applications. The tests concerned data sorting, prime numbers determination, bitmap modifi-cation, saving to the database and reading from a text file. The series of repetitions of each test were performed on Sam-sung and Xiaomi devices. The following criteria were used: test execution time, CPU load, and RAM usage. The per-formance, in most of the carried out tests, was in favor of the C++ language, and the main difference and with the great-est discrepancy between the technologies tested was the execution time, where C++ scored 18 points, and Java 3 points. For the CPU usage, the result was the same, but value differences were smaller. A nondiscerning parameter that was the use of RAM. C++ received 11 points and Java 10.

14

Porównanie wydajności aplikacji internetowych na przykładzie szkieletów programistycznych Laravel i Vaadin

Radomski Jakub

Journal of Computer Sciences Institute

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2022

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Vol. 22

35--39

PL

Artykuł przedstawia wyniki porównania wydajności aplikacji internetowych napisanych przy użyciu szkieletów aplikacji Laravel oraz Vaadin. Celem badania było wskazanie, który szkielet oferuje lepszą wydajnośćczasową oraz zweryfikowanie postawionej tezy brzmiącej “Aplikacja internetowa stworzona przy użyciu platformy programistycznej Vaadin jest bardziej wydajna niż aplikacja stworzona za pomocą platformy Laravel”. Do przeprowadzenia badania wykorzystano metodę badawczą opartą na analizie porównawczej i przy pomocy dwóch aplikacji zbadano między innymi pręd-kość generowania zasobów, czy czasy uzyskane w pracy pod obciążeniem. Przeprowadzono próby według 13 scenariuszy badań a otrzymane wyniki pozwoliły jednoznacznie zweryfikować, że postawiona teza została udowodniona.

EN

The article presents the result of comparing the performance of web applications written with the use of Laravel and Vaadin frameworks. The aim of the study was to identify which framework offers better time efficiency and to verify the thesis: "A web application created using the Vaadin framework is more efficient than an application created using the Laravel framework". A research method based on a comparative analysis was used to conduct the study and with the help of two applications was tested the speed of resource generation, or the times obtained in work under load. Tests were carried out according to 13 research scenarios and the obtained results allowed to clearly verify the thesis was proven.

15

Analysis of mining accident levels against the background of changes in productivity and employment in the hard coal mining industry

Wyganowska Małgorzata, Tobór-Osadnik Katarzyna

Inżynieria Mineralna

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2022

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no. 1

117--121

EN

Occupational safety is an extremely important area of concern in every company. In mining companies, it occupies a particularly high position in the hierarchy of tasks and objectives. An accident at work is defined as a sudden event, caused by an external cause, resulting in injury or death of a worker and which occurred in connection with work. An accidental event consists of a number of interrelated adverse technical, organisational, environmental and human events. However, it is recognised that human error (interference) is usually the initiating factor of an accident at work. Among the causes of errors can be distinguished primarily: human failure, characteristics of the tasks performed, the conditions of the physical environment and the impact of the social environment, technical conditions. Therefore, within the framework of accident prevention, apart from the technical sphere, attention is also paid to the sphere of management – motivation, proper training, information flow, as well as assessment of psychophysical features of employees and their adaptation to the workplace. It is even more justified in the situation, where as it results from many years' data of the Central Statistical Office (GUS), the so-called human factor is responsible for about 60% of accidents at work in Poland. €e level of accidents can be analysed from several angles. Interesting is correlation of level of accidents from factors, which have influence on management. €en it is possible by controlling these elements to influence the number of accidents at work. It is especially important in such branch as mining, in which according to GUS data the highest number of accidents was registered in Poland. Intuitively, most causes of accidents, according to the literature, are caused by human factors. A fall in the accident rate should be a natural consequence of a reduction in the workforce. However, a reduction in employment must not result in a decrease in labour productivity. In this article, the authors present the results of a study of correlation between these three indicators: employment level, productivity and accident rate, in Polish coal mines over the period 2003–2020.

PL

Bezpieczeństwo pracy jest niezwykle istotnym obszarem troski w każdym przedsiębiorstwie. W przedsiębiorstwach wydobywczych zajmuje wyjątkowo wysoka pozycję w hierarchii zadań i celów. Wypadek przy pracy definiuje się jako zdarzenie nagłe, wywołane przyczyną zewnętrzną, powodujące uraz lub śmierć pracownika, a które nastąpiło w związku z pracą. Na zdarzenie wypadkowe składa się wiele powiązanych ze sobą niekorzystnych zdarzeń technicznych, organizacyjnych, środowiskowych i ludzkich. Uznaje się jednak, że zazwyczaj czynnikiem inicjującym wypadek przy pracy jest błąd (zakłócenie) człowieka. Pośród przyczyn popełniania błędów można wyróżnić przede wszystkim: niesprawność człowieka, cechy realizowanych zadań, warunki fizycznego środowiska oraz wpływ środowiska społecznego, uwarunkowania techniczne. Dlatego w ramach profilaktyki wypadkowości oprócz sfery technicznej zwraca się uwagę również na sferę zarządzania – motywację, prawidłowe szkolenie, przepływ informacji, a także ocena cech psychofizycznych pracowników i ich dopasowania do stanowiska pracy. Jest to tym bardziej uzasadnione w sytuacji, gdzie jak wynika z wieloletnich danych GUS, za około 60% wypadków przy pracy w Polsce odpowiedzialny jest tzw. czynnik ludzki. Poziom wypadkowości można rozpatrywać w kilku ujęciach. Interesująca jest korelacja poziomu wypadkowości od czynników, na które ma wpływ kierownictwo. Wtedy można sterując tymi elementami wpływać na liczbę wypadków przy pracy. Jest to szczególnie ważne w takiej branży jak górnictwo, w którym według danych GUS odnotowano ich najwięcej w Polsce. Intuicyjnie naturalnym następstwem zmniejszenia zatrudnienia powinien być spadek poziomu wypadkowości. Jednakże zmniejszenie stanu zatrudnienia nie może powodować spadku wydajności pracy. W artykule autorki zaprezentowały wyniki badania korelacji między tymi trzema wskaźnikamiwskaźnikami: poziomem zatrudnienia,wydajnością i wypadkowością, w polskich kopalniach węgla kamiennego na przestrzeni lat 2003–2020.

16

Optimisation of biochar yield from sorted wood wastes as sustainable alternatives to burning to ash

Adeodun Similade A., Sangodoyin Abimbola Y., Ogundiran Mary B.

Ecological Chemistry and Engineering. S

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2022

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Vol. 29, nr 1

15--26

EN

Wood wastes are one of the leading contributors of greenhouse gases cum climate change. While the burning of wood wastes results in CO2 emission, decomposition generates methane. In place of these emissions, wood wastes can be converted into biochars which have a lot of novel applications. However, low biochar yield was the common limitation of wood wastes, essentially, due to a mixture of different classifications of trees that pyrolyse at different conditions. In this study, biochar yield from sorted wood wastes was optimised by varying pyrolysis temperature and time. Power consumption, cost, and carbon footprint of the optimised biochar and ash were compared for both hydropower grid and diesel generator scenarios. Optimal pyrolysis yields were 33.6 % (400 °C), 29.4 % (350 °C) and 18.5 % (400 °C) respectively for hardwood sawdust char (HSC), softwood sawdust char (SSC), and mixed sawdust char (MSC) at 2 hours duration for all materials. The CO2 emissions from ash were 2.49 kg and 19.0 kg respectively for grid and diesel power supply. The diesel generator power was 17 times more expensive than grid power for wood wastes pyrolysis. Wood wastes have better biochar yield when charred homogenously; they have a smaller carbon footprint and are cheaper when produced with power from the grid. Wood wastes in place of being burnt can be processed as inexpensive and environment-friendly biochar.

17

Automated lung nodule detection in CT images by optimized CNN: impact of improved whale optimization algorithm

Kumar M. Kiran, Amalanathan Anthoniraj

Computer Assisted Methods in Engineering and Science

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2022

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Vol. 29, no. 1-2 spec.

7--31

EN

Lung cancer is one of the leading causes of cancer-related deaths among individuals.It should be diagnosed at the early stages, otherwise it may lead to fatality due to itsmalicious nature. Early detection of the disease is very significant for patients’ survival, andit is a challenging issue. Therefore, a new model including the following stages: (1) imagepre-processing, (2) segmentation, (3) proposed feature extraction and (4) classificationis proposed. Initially, pre-processing takes place, where the input image undergoes specificpre-processing. The pre-processed images are then subjected to segmentation, which iscarried out using the Otsu thresholding model. The third phase is feature extraction, wherethe major contribution is obtained. Specifically, 4D global local binary pattern (LBP)features are extracted. After their extracting, the features are subjected to classification,where the optimized convolutional neural network (CNN) model is exploited. For a moreprecise detection of a lung nodule, the filter size of a convolution layer, hidden unit inthe fully connected layer and the activation function in CNN are tuned optimally byan improved whale optimization algorithm (WOA) called the whale with tri-level enhancedencircling behavior (WTEEB) model.

18

The tests of micro-CHP prototype with SI engine powered by LPG and natural gas

Przybyła Grzegorz, Ziółkowski Łukasz, Buczak Mateusz, Żmudka Zbigniew

Combustion Engines

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2022

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R. 61, nr 2

47--53

EN

This paper presents the experimental results of a Combined Heat and Power (CHP) prototype based on a SI V-twin internal combustion engine driving a synchronous generator. The paper presents the criteria that were used to select the combustion engine and the electrical generator for the prototype. The internal combustion engine has been adapted to be fuelled by natural gas or LPG, with the possibility of controlling the load in two ways, i.e. by changing the throttle position (quantitatively) and/or the value of the excess air ratio by changing the fuel dose at a constant throttle position (qualitatively). The applied method of control allows to improve the efficiency of the engine especially in the range of partial loads. The experimental tests were carried out at a constant speed of 1500 rpm. During the tests, the fuel consumption of the internal combustion engine, the composition of the exhaust gas at the outlet of the exhaust system, the electrical parameters of the synchronous generator and the temperature at selected locations of the CHP system instance were measured. According to the obtained results, there was a slight increase in the efficiency of electricity generation with the application of the developed method of control of the combustion engine. The maximum power generation efficiency for Natural Gas (NG) was higher compared to LPG by more than 2 percentage points. The exhaust gas emission level confirm that the prototype cogeneration system meets the Stage II emission standard (in accordance with Directive 2002/08/EC for small SI engines with a power below 19 kW. D2 ISO 8178).

19

Investigation of thermal decomposition and gases release from pre-drying municipal solid waste (PMSW) via pyrolysis technology

Jamro Imtiaz Ali, Khoso Salim, Shah Syyed Adnan Raheel, Ali Sadaquat, Ali Fahmeed, Hassane Haseeb Ul

Architecture Civil Engineering Environment

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2022

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Vol. 15, no. 4

119--131

EN

Present study investigates the thermal decomposition and syngas potential of pre-drying municipal solid waste (PMSW) via pyrolysis using thermo-gravimetric (TGA) analyzer coupled with the mass spectrometer (MS). The experiments were performed at the heating rates 5 and 15°C/min. Differential thermo-gravimetric (DTG) curves exposed four conversion phases at lower heating rate and two conversion phases at higher heating rate. MS analysis of the evolved gases H2, CO, and CH4 revealed that the devolatilization phase played a major role during the processes. Higher H2 generation was observed at a lower heating rate due to more contact among PMSW and process temperature. Higher CO and CH4 were also favored at lower heating rate. Total yield of gases was found higher due to higher CO generation. For the estimation of activation energy (Ea), Flynn-Wall-Ozawa (FWO) kinetic model was applied at the conversion rates (αα) ranged from 5-35. In overall, the lower heating rate supported the higher WMSW conversion as well as higher gas released during the process. Hence, this study will help to evaluate the H2 potential of the PMSW using pyrolysis thermal technology.

20

Analysis of teff market chain: evidence from South Gondar Zone, Ethiopia

Negussie Mengistu, Woldeamanuel Teshale, Tefera Tewodros

Acta Innovations

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2022

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no. 43

15--35

EN

Dera is one of the potential districts in teff production. Nonetheless, there are some restraints and prospects in teff commercialization still unaccustomed. This study initiates to examine the teff market chain in the Dera district. It concentrates to synthesize the behavior, transparency, and effectiveness of teff market expending data from different sources. It involved teff producers, wholesalers, retailers, rural assemblers, cooperatives, urban assemblers and processors. The data investigation engaged expressive inferential statics & SCP model. Concerning marketing, the result indicates that producers supplied to the market via rural retailers, wholesalers and directly to consumers 57.7% of teff produced in 2017 cropping season. There are eleven marketing channels in transferring 2268 Quintals of teff from farmers to different intermediaries until reaching end buyers. The market structure of teff is weakly oligopolistic, implying that the market is not competitive. The producers' share of margin for the teff market accounts 68.96% associated with a 31.04% total gross margin. The marketing channel with more teff supplied can have a high or low marketing margin depending on the presence of value-adding market agents in the track. It implies that the channel with more teff supplied is not necessarily the channel in which the highest market margin. The marketing agents in the study area incur primary transaction costs like packing, loading and unloading, storage, transportation, communication and other personal costs. Therefore, improved bargaining power, access to accurate market information and infrastructural development are essential for a better performing teff market.