Wyniki wyszukiwania - BazTech

1

Sound wave diffraction difference index for noise barrier with added device

Piechowicz Janusz

Vibrations in Physical Systems

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2023

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Vol. 34, nr 2

art. no. 2023207

EN

The diffraction phenomenon at the edge of the acoustic screen is of fundamental importance for forming the acoustic shadow area in the space outside the screen. The so-called added devices construction solutions are increasingly used on plane sound barriers, often used as anti-noise solutions on roads and railway lines. Added devices with various geometric shapes; aim to change the diffraction conditions at the noise-reducing devices' top edge. Adrienne method was developed in a European research project, the aim of which was the measurement on site of sound absorption and sound transmission of any road noise barrier. The European Adrienne project has developed a diffraction difference index at the top edge of an acoustic screen and a method for its determination to compare the effectiveness of the screen with and without the added device. The diffraction difference index is a single-number rating of the design solution mentioned. Measurements for index calculations are made by comparing the impulse response of screens with and without the added device using MLS (Maximum Length Sequence) signals.

2

Aggregated indices in quality assessment of selected geoinformation websites

Król Karol

Geomatics, Landmanagement and Landscape

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2023

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no. 3

47--59

EN

Map portals can facilitate the work of public administration units and improve access to information, although they have to present high material and technical quality. Not without significance are also measures supporting these websites. This paper aims to assess the quality of selected geoinformation websites. The study was carried out in the form of a quality audit with the use of selected web applications provided in a freeware, thin-client model. A comparative analysis was performed on three versions of the geoservice functioning for the Tomice municipality (accessed on 5th July 2023): 1) eMPZP website (https://www.tomice.pl/mpzp/), 2) municipal geoportal (http://www.mpzp.tomice.pl), and 3) municipal map portal (https://sip.gison. pl/tomice). The measurements were taken only once and in an ad hoc manner. The tests were performed in selected quality dimensions: responsiveness, performance, content and hyperlink quality, accessibility for people with disabilities, syntactic code correctness, search engine optimisation (SEO), and usage indicators, with special emphasis on overall quality. The conclusion was that each of the geoportals evaluated presents good quality. However, it would be wrong to compare them in absolute terms, as the quality of these services should be assessed through the lens of the different times in which they operate.

PL

Podmioty, które dostrzegają potencjał analityki internetowej coraz częściej monitorują witryny i aplikacje internetowe, odnotowując wzorce zachowań użytkowników, analizując jakość serwisów oraz poszukując obszarów wymagających optymalizacji. Dojrzała kultura analityczna pozwala skutecznie wykorzystywać dane w procesie decyzyjnym [Röglinger i in. 2012]. Sektor prywatny korzysta z analityki internetowej znacznie częściej i w stopniu bardziej zaawansowanym, w porównaniu do jednostek administracji publicznej, w tym samorządów terytorialnych. Ponadto znacznie częściej wykonuje audyty, których celem jest poprawa jakości posiadanych serwisów internetowych [Alghenaim i in. 2023]. Portal mapowy może wpłynąć na usprawnienie pracy jednostek administracji publicznej oraz zwiększenie dostępu do informacji, jednak musi być on wysokiej jakości merytorycznej i technicznej. Nie bez znaczenia są też działania podejmowane w otoczeniu portalu. Celem pracy jest ocena jakości wybranych serwisów geoinformacyjnych. Badania wykonano w formie audytu jakości, z zastosowaniem wybranych aplikacji internetowych udostępnianych w modelu freeware, thin-client. Analizie porównawczej poddano trzy wersje geoserwisu gminy Tomice (dostęp z dnia 05.07.2023): 1) serwis eMPZP (https://www.tomice.pl/mpzp/), 2) geoportal gminy (http://www.mpzp.tomice.pl) oraz 3) gminny portal mapowy (https://sip.gison.pl/tomice). Pomiary miały charakter jednostkowy typu ad-hoc. Testy wykonano w wybranych płaszczyznach jakości: responsywności, wydajności, jakości treści i hiperłączy, dostępności dla osób z niepełnosprawnościami, poprawności składniowej kodu, stopnia optymalizacji dla wyszukiwarek (SEO) oraz wskaźników użytkowania, ze szczególnym uwzględnieniem jakości globalnej. W konkluzji zwrócono uwagę, że każdy z ocenianych geoserwisów jest dobrej jakości. Błędem jest porównywanie ich w sposób bezwzględny, ponieważ jakość tych serwisów powinna być oceniana przez pryzmat ery w jakiej funkcjonowały.

3

Deposition effect of carbon deposits on charge flow in EGR valve equipped CI engine

Woźniak Marek, Siczek Krzysztof, Zakrzewski Sergiusz, Just Paweł, Ozuna Gustavo, Onescu Constantin

Combustion Engines

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2023

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R. 62, nr 1

26--35

EN

The exhaust gas recirculation (EGR) valve regulates the exhaust gas flow between the engine exhaust manifold and the inlet one. This allows the inlet air to warm up, improving fuel evaporation and reducing the combustion temperature of the charge. Such a valve reduces the number of harmful substances in the exhaust gases. The valve tends to stick when too much sediment builds on the walls of the exhaust system, especially during driving in urban conditions or when leaks in the vacuum or exhaust pipes occur. A faulty valve causes the engine to run unevenly at idle speed and under light loads. The defective EGR valve weakens the inlet manifold capacity, increases combustion, causes clogging of the particulate filter and damage to the lambda probe. Blocked EGR valve may lead to engine immobilization as a result of its computerized control system operations. A model of an EGR valve for a selected diesel engine was developed to determine velocity distribution of the load flowing in it for different values of the degree of valve opening and the volume of deposits on the valve walls. The volume of accumulated carbon deposits on the walls of the EGR valve was measured using a real engine. Based on the recorded mileage of the vehicle, the assumed average speed of the car and the driving style of the driver and the intensity of deposition of carbon particles on the walls was estimated.

4

Multi-objective optimization of PCM-fin structure for staggered Li-ion battery packs

Qiu Chenghui, Wu Chongtian, Yuan Xiaolu, Wu Linxu, Yang Jiaming, Shi Hong

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e145677

EN

Endurance capability is a key indicator to evaluate the performance of electric vehicles. Improving the energy density of battery packs in a limited space while ensuring the safety of the vehicle is one of the currently used technological solutions. Accordingly, a small space and high energy density battery arrangement scheme is proposed in this paper. The comprehensive performance of two battery packs based on the same volume and different space arrangements is compared. Further, based on the same thermal management system (PCM-fin system), the thermal performance of staggered battery packs with high energy density is numerically simulated with different fin structures, and the optimal fin structure parameters for staggered battery packs at a 3C discharge rate are determined using the entropy weight-TOPSIS method. The result reveals that increasing the contact thickness between the fin and the battery (X) can reduce the maximum temperature, but weaken temperature homogeneity. Moreover, the change of fin width (A) has no significant effect on the heat dissipation performance of the battery pack. Entropy weight-TOPSIS method objectively assigns weights to both maximum temperature (Tmax) and temperature difference (DT) and determines the optimal solution for the cooling system fin parameters. It is found that when X = 0:67 mm, A = 0:6 mm, the staggered battery pack holds the best comprehensive performance.

5

Determining parameters to optimize the pulling force for the luffing jib tower cranes by Taguchi method

Duong Truong Giang

Archive of Mechanical Engineering

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2023

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LXX, nr 3

387--407

EN

The presented problem consists in optimizing the pulling force of the luffing jib tower cranes, in order to reduce power and save energy by determining reasonable geometrical parameters such as placement of pulley assemblies, position of jib pin, and jib length. To determine the optimal parameters, a mechanical model was developed to calculate the pulling force of the research object. Then, the Taguchi method and Minitab software were applied to evaluate the influence of the parameters. The objective function was the minimum pulling force of the luffing jib. The calculation results show that the position of the pulley assembly used to pull the jib is the most influential factor on the objective function accounting for 81.15%, the less significant factors are the jib length, the pin position of the jib, and the pulley assembly that changes the direction of the load lifting cable. The result of the test presented in the article allowed for determining the rational parameters, and the optimal position of the pulley assemblies on the top of the crane. In the case of the pulley assembly located at the top of the crane, one obtains the optimal height of the crane head H≈0.4 L c.

6

Application of the OpenCV library in indoor hydroponic plantations for automatic height assessment of plants

Pietrzykowski Sławomir Krzysztof, Wymysłowski Artur

Journal of Automation Mobile Robotics and Intelligent Systems

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2022

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Vol. 16, No. 2

55--63

EN

This paper presents a method for automatically measuring plants’ heights in indoor hydroponic plantations using the OpenCV library and the Python programming language. Using the elaborated algorithm and Raspberry Pi-driven system with an external camera, the growth process of multiple pak choi cabbages (Brassica rapa L. subsp. Chinensis) was observed. The main aim and novelty of the presented research is the elaborated algorithm, which allows for observing the plants’ height in hydroponic stations, where reflective foil is used. Based on the pictures of the hydroponic plantation, the bases of the plants, their reflections, and plants themselves were separated. Finally, the algorithm was used for estimating the plants’ heights. The achieved results were then compared to the results obtained manually. With the help of a ML (Machine Learning) approach, the algorithm will be used in future research to optimize the plants’ growth in indoor hydroponic plantations.

7

Air bottoming combined cycle performance analyses by the combined effect of variable parameters

Khan Mohammad N, Alzafiri Dhare

Archive of Mechanical Engineering

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2022

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LXIX, nr 3

497--517

EN

To meet the continuous demand for energy of industrial as well as commercial sectors, researchers focus on increasing the power generating capacity of gas turbine power plants. In this regard, the combined cycle is a better solution in terms of environmental aspects and power generation as compared to a simple gas turbine power plant. The present study is the thermodynamic investigation of five possible air bottoming combined cycles in which the topping cycle is a simple gas turbine cycle, regenerative gas turbine cycle, inter-cool gas turbine cycle, reheat gas turbine cycle, and intercool-reheat gas turbine cycle. The effect of pressure ratio of the topping cycle, the turbine inlet temperature of topping cycle, and ambient temperature on net power output, thermal efficiency, total exergy destruction, and exergetic efficiency of the combined cycle have been analyzed. The ratio of the net power output of the combined cycle to that of the topping cycle is maximal in the case when the topping cycle is a simple gas turbine cycle. The ratio of net power output and the total exergy destruction of the combined cycle to those of the topping cycle decrease with pressure ratio for all the combinations under study except for the case when the topping cycle is the regenerative gas turbine cycle.

8

An assessment of applicability of the two-dimensional wavelet transform to assess the minimum chip thickness determination accuracy

Gogolewski Damian, Makieła Włodzimierz, Nowakowski Łukasz

Metrology and Measurement Systems

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2020

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Vol. 27, nr 4

659--672

EN

The objective of the study was to assess the potential use of optical measuring instruments to determine the minimum chip thickness in face milling. Images of scanned surfaces were analyzed using mother wavelets. Filtration of optical signals helped identify the characteristic zones observed on the workpiece surface at the beginning of the cutting process. The measurement data were analyzed statistically. The results were then used to estimate how accurate each measuring system was to determine the minimum uncut chip thickness. Also, experimental verification was carried out for each mother wavelet to assess their suitability for analyzing surface images.

9

Development of real gas model operating in gas turbine system in Python programming environment

Trawiński Paweł

Archives of Thermodynamics

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2020

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Vol. 41, no 4

23--61

EN

Identification of working fluids and development of their mathematical models should always precede construction of a proper model of the analysed thermodynamic system. This paper presents method of development of a mathematical model of working fluids in a gas turbine system and its implementation in Python programming environment. Among the thermodynamic parameters of the quantitative analysis of systems, the following were selected: specific volume, specific isobaric and isochoric heat capacity and their ratio, specific enthalpy and specific entropy. The development of the model began with implementation of dependencies describing the semi-ideal gas. The model was then extended to the real gas model using correction factors reflecting the impact of pressure. The real gas equations of state were chosen, namely due to Redlich–Kwong, Peng–Robinson, Soave– Redlich–Kwong, and Lee–Kesler. All the correction functions were derived analytically from the mentioned equations of real gas behaviour. The philosophy of construction of computational algorithms was presented and relevant calculation and numerical algorithms were discussed. Created software allowed to obtain results which were analysed and partially validated.

10

Acoustic Characterization of a Room : Study Case Between Simulation and a Portable Method

Ibarra-Zarate David, Padilla-Ortiz Ana Laura

Archives of Acoustics

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2020

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Vol. 45, No. 1

153--163

EN

Large venues and auditoriums are commonly associated with their astounding architecture. Their acoustic quality is an essential factor in its qualification as a great and functional, or a badly designed place. However, acoustics is often overlooked during the design stage of a building due to the complexity and high cost of the measurements involved. For this reason, it is important to explore more accessible ways to implement acoustics evaluations. The aim of this work is to compare typical experimental measuring methods and the use of mobile devices to assess the acoustic quality of a room. These measurements are contrasted with the software simulation of the same acoustical space. The results show that the mobile system can be used for professional measurements with low restrictions in the frequency range of interest of this study (90 Hz to 4000 Hz).

11

Porównanie narzędzi do tworzenia aplikacji typu SPA na przykładzie Ember i React

Wróbel Jacek

Journal of Computer Sciences Institute

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2019

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Vol. 11

145--148

PL

W artykule przedstawiono wyniki porównania narzędzi do tworzenie aplikacji typu SPA przy użyciu platformy programistycznej Ember oraz React. Badania przeprowadzono z wykorzystaniem aplikacji testowych o takiej samej funkcjonalności, ale zaimplementowanych na obu platformach. Porównanie dotyczyło struktury projektu, wybranych metryk kodu oraz efektywności renderowania stron.

EN

The article presents the results of comparison of tools for creating SPA applications using the Ember and React framework. The research was carried out using test applications with the same functionality but implemented on both platforms. The comparison concerned the structure of the project, selected code metrics and the effectiveness of page rendering.

12

Porównanie możliwości tworzenia aplikacji PHP na przykładzie Yii2 i Laravel

Sydorchuk Olena

Journal of Computer Sciences Institute

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2019

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Vol. 11

125--130

PL

W pracy przedstawiono wyniki porównania możliwości tworzenia aplikacji internetowych w technologii PHP na przykładzie popularnych platform programistycznych Yii2 i Laravel. Badania zostały zrealizowane poprzez implementację dwóch aplikacji o takiej samej funkcjonalności, korzystającej z tej samej bazy danych. W obu technologiach porównano strukturę aplikacji, elementy tworzenia interfejsu graficznego, wybrane metryki kodu oraz efektywność pracy z bazami danych. W podsumowaniu wskazano najważniejsze wady i zalety obu rozwiązań.

EN

The paper presents the results of comparison of the possibilities of creating web applications in PHP technology on the example of popular programming platforms Yii2 and Laravel. The research was carried out by implementing two applications with the same functionality using the same database. In both technologies, the application structure, elements of creating the graphical interface, selected code metrics and efficiency of working with databases were compared. The summary indicates the most important advantages and disadvantages of both solutions..

13

Using LabVIEW and ros for planning and coordination of robot missions, the example of ERL emergency robots and university rover challenge competitions

Węgierska Agnieszka, Andrzejczak Kacper, Kujawiński Mateusz, Granosik Grzegorz

Journal of Automation Mobile Robotics and Intelligent Systems

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2019

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Vol. 13, No. 2

68--81

EN

The article presents the main functionalities and principles for operating a software for multi-robotic mission coordination developed for competitions ERL Emergency Robots 2017, as well as its adaptation during University Rover Challenge. We have started with an overview of similar software used in commercial applications or developed by other research groups. Then, our solution is thoroughly described, with its user interface made in LabVIEW and the communication layer based on ROS software. Two cases of robotic competitions proved our software to be useful both for planning and for managing the mission. The system supports the operator in teleoperation and during partial autonomy of the robots. It offers reporting on the robots’ positions, Points of Interest (POI), tasks status. Reports are generated in KML/KMZ formats, and allow us to replay the mission, and analyze it.

14

Assessment of wind energy resources using artificial neural networks – case study at Łódź Hills

Korupczyński R., Trajer J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2019

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Vol. 67, nr 1

115--124

EN

The aim of this paper is to answer the question: Are the Łódź Hills useful for electrical energy production from wind energy or not? Due to access to short-term data related to wind measurements (the period of 2008 and 2009) from a local meteorological station, the measure – correlate – predict approach have been applied. Long-term (1979‒2016) reference data were obtained from ECWMF ERA-40 Reanalysis. Artificial neural networks were used to calculate predicted wind speed. The obtained average wind speed and wind power density was 4.21 ms–1 and 70 Wm–1, respectively, at 10 m above ground level (5.51 ms–1, 170 Wm–1 at 50 m). From the point of view of Polish wind conditions, Łódź Hills may be considered useful for wind power engineering.

15

Energy efficiency analysis of railway turnout heating system with a melting snow model heated by classic and contactless heating method

Flis Mateusz

Archives of Electrical Engineering

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2019

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Vol. 68, nr 3

511--520

EN

Maintaining railway turnout operability is crucial for ensuring railway transport safety. Electric heating of railway turnouts is a significant technical and economic issue. The classical heating is characterised by high power consumption. For this reason, research is needed to optimise the current system. This paper presents results of a numerical analysis and of experimental researches. The numerical analysis was carried out using the ANSYS software. There was conducted a numerical comparative analysis of energy loss during heating performed using two different heaters. Including the classical method and a heater thermally insulated from a rail. In the first step, heating of a working space filled with a substitute snow model was considered. The snow-covered surface area was held within the working space of the turnout. It was assumed that the snow substitute material had thermal properties approximately the same as real light snow. It was also assumed that the material is in the solid state which would not undergo a phase change. In the next step, a real snow model that included the phase change process was taken into account. The energy efficiency and heat distribution in the turnout have been analysed and compared. The experimental researches were carried out in a physical model. The results showed that the use of a contactless heater results in creating a larger area over which emitted heat affected snow in the working space. Consequently, more snow was melted around the contactless heater than the classic one. This experimental observation supported the results of the numerical analyses presented previously.

16

Transverse vibration analysis of nonlocal beams with various slenderness ratios, undergoing thermal stress

Babaei Alireza, Rahmani Arash, Ahmadi Isa

Archive of Mechanical Engineering

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2019

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Vol. LXVI, nr 1

5--24

EN

In this paper, thermally-excited, lateral free vibration analysis of a small-sized Euler-Bernoulli beam is studied based on the nonlocal theory. Nonlocal effect is exerted into analysis utilizing differential constitutive model of Eringen. This model is suitable for design of sensors and actuators in dimensions of micron and submicron. Sudden temperature rise conducted through the thickness direction of the beam causes thermal stresses and makes thermo-mechanical properties to vary. This temperature field is supposed to be constant in the lateral direction. Temperatures of the top and bottom surfaces of the system are considered to be equal to each other. Governing equation of motion is derived using Hamilton’s principle. Numerical analysis of the system is performed by Galerkin’s approach. For verification of the present results, comparison between the obtained results and those of benchmark is reported. Numerical results demonstrate that dynamic behavior of small-sized system is been effected by temperature shift, nonlocal parameter, and slenderness ratio. As a result, taking the mentioned parameters into account leads to better and more reliable design in miniaturized-based industries.

17

Decomposition algorithm for tool path planning for wire-arc additive manufacturing

Nguyen L., Buhl J., Bambach M.

Journal of Machine Engineering

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2018

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Vol. 18, No. 1

95--106

EN

Three-axis machines are limited in the production of geometrical features in powder-bed additive manufacturing processes. In case of overhangs, support material has to be added due to the nature of the process, which causes some disadvantages. Robot-based wire-arc additive manufacturing (WAAM) is able to fabricate overhangs without adding support material. Hence, build time, waste of material, and post-processing might be reduced considerably. In order to make full use of multi-axis advantages, slicing strategies are needed. To this end, the CAD (computer-aided design) model of the part to be built is first partitioned into sub-parts, and for each sub-part, an individual build direction is identified. Path planning for these sub-parts by slicing then enables to produce the parts. This study presents a heuristic method to deal with the decomposition of CAD models and build direction identification for sub-entities. The geometric data of two adjacent slices are analyzed to construct centroidal axes. These centroidal axes are used to navigate the slicing and building processes. A case study and experiments are presented to exemplify the algorithm.

18

Methods for detection analysis in quality control system

Kania K., Rymarczyk T.

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2018

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T. 8, nr 3

35--38

EN

The article contains a description of the quality control system based on optical detection algorithms. It plays an increasingly important in the production process. The development of new systems based on the technology of optical detection methods to a large degree can improve the production process at different stages.

PL

Artykuł zawiera opis systemu kontroli jakości oparty na optycznych algorytmach detekcji. Wykrywanie uszkodzeń odgrywa coraz większą rolę w procesie produkcyjnym. Opracowanie nowych systemów opartych na technologiach optycznych metod wykrywania w dużym stopniu może usprawnić proces produkcji na różnych jego etapach.

19

BIM - Rewolucja Budownictwa Cyfrowego

Magiera J.

Builder

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2018

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R.22, nr 1

88--90, 92--94

20

Study of Fluid Flow and Solidification in Billet Caster Continuous Casting Mold with Electromagnetic Stirring

Maurya A., Kumar Jha P.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

413--424

EN

Electromagnetic stirrer generates swirling fluid flow, boosts the mixing of molten steel near the solidification front and enhances the quality of the continuously cast products. In the present investigation, attention is paid towards studying the effect of in-mold electromagnetic stirring on fluid flow and solidification. A three-dimensional coupled mathematical model of solidification and magnetohydrodynamics has been established for billet caster mold. The alternating magnetic field is applied to the solidification model where fluid flow, heat transfer, and electromagnetic equations are solved simultaneously. It has been found that an increase in field frequency decreases the length of stirring and the liquid fraction of the steel at the center of the mold exit. Tangential velocity near the solidification front increases with the magnetic field frequency or flux density, due to which, a break in solidified shell near stirrer position is predicted whose width increases accordingly.