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Analysis of the influence of the spark plug on exhaust gas composition
No full textThis paper analyses the influence of the type of electrode in a spark plug on exhaust gas emission. The objects of the research were the following vehicles of different years of production: the Volkswagen Beetle 1300, the Honda Nighthawk 650, the BMW e46 318i, the Hyundai i10, and the Audi A4 B6. The vehicles were powered by petrol and LPG. Spark plugs were selected for the vehicles, with different kinds of construction for the main electrodes and different numbers of poles but with similar heat values. A comparative analysis of the composition of the exhaust gas mixture was performed, depending on the set of spark plugs used. The amount of CO, HC, CO2, and O2 emissions was analysed. The results were compared with the applicable exhaust gas emission standards. Both in the case of E5 95 petrol and LPG gas, lower exhaust gas emissions were observed when iridium spark plugs were used.iss. 11vol. 1
Dome Skylights Implementation and Feasibility Analysis
No full textBaigiamajame magistro darbe analizuojamos kupolinių stoglangių panaudojimo galimybės. Remiantis mokslinės literatūros teorine apžvalga išnagrinėtos kupolinių stoglangių rūšys, įvertintas teisinis stoglangių reglamentavimas ir įstatyminė bazė – statybos techninis reglamentas, standartai, sertifikavimas ir patentai. Darbe apžvelgtos naujausios stoglangių panaudojimo tendencijos ir perspektyvos. Atvejų analizės dalyje palygintas kupolinių stoglangių taikymas švietimo įstaigose, prekybos centruose, gamyklose ir sandėliuose bei įvertinta stoglangių įtaka žmogui. Praktinėje dalyje atlikta ekspertinė apklausa ir daugiakriteris kupolinių stoglangių sluoksnių vertinimas SAW, COPRAS ir TOPSIS metodais. Remiantis gautais teorinių ir empirinių tyrimų rezultatais, nustatyti prioritetiniai stoglangių efektyvumo rodikliai ir parengtas kupolinių stoglangių panaudojimo galimybių modelis su grafiniu dvimačiu brėžiniu. Trisluoksnio kupolo stoglangio modelis tarpusavyje sujungia stoglangio charakteristikų rinkinį ir integruojamų technologinių sprendinių kompleksą. Apibendrinus, pateikti pasiūlymai, skirti statybos sektoriaus atstovams, t. y. verslo subjektams, pastatų vystytojams, projektuotojams ir architektams bei stoglangių gamintojams. Darbą sudaro šios dalys: įvadas, literatūros apžvalga, atvejų taikymo analizė, daugiakriteris vertinimas, projektinė dalis – modelis, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis 84 p. teksto be priedų, 37 paveikslai, 22 lentelės, 93 literatūros šaltiniai. Atskirai pridedami darbo priedai.The master thesis examines dome skylights implementation and feasibility. Based on the theory overview of scientific literature there were dome skylights types analyzed, legal regulation and framework evaluated – construction technical regulation, standards, certification and patents. The final thesis reviews the latest trends and perspectives in the use of skylights. Related with case study part, implementation of skylights in educational institutions, shopping centres, industrial buildings and warehouses were analyzed as well as the impact of skylights to humans have been evaluated. In the practical part, there were survey of experts conducted and multi-criteria evaluation of dome skylights layers performed by SAW, COPRAS and TOPSIS methods. Based on the results of theoretical and empirical research, the priority indicators of the efficiency of skylights were determined and a model of the possibilities of using dome skylights with a graphical two-dimensional drawing was developed. The three-layer dome skylight model interconnects a set of skylight characteristics and a complex of integrated technological solutions. In the conclusion, proposals have been provided for the representatives of the construction sector, including business entities, building developers, designers, architects and skylight manufacturers. Thesis consists of: 84 p. text without appendixes, 37 pictures, 22 tables, 93 literature entries. Appendixes included
Analysis of gardeners' communities conversion into residential areas
No full textŠiame darbe nagrinėjama sodininkų bendrijų konversijos į gyvenamąsias teritorijas procesai. Šiam darbui atlikti nagrinėjamos sodininkų bendrijos, esančios Vilniaus rajono teritorijoje. Darbo tikslas yra išanalizuoti, ar sodininkų bendrijos, esančios Vilniaus rajone, funkcionuoja kaip savarankiškos gyvenvietės. Iš visų 261 Vilniaus rajone esančių sodininkų bendrijų buvo pasirinktos dvi, remiantis atlikta esamos būklės analize, tinkamiausios nagrinėti sodininkų bendrijos: „Girios–7“, esanti Bezdonių sen., Zamečkavo k., ir „Kloniai“, esanti Nemėžio sen., Pakalniškių k. Siekiant įvertinti išrinktų sodininkų bendrijų funkcines ir socialines reikmes, buvo apklausti sodininkų bendrijų pirmininkai. Atsižvelgiant į atliktą interviu sodininkų bendrijoms pasiūti sprendimo variantai jų darnaus vystymosi link: pirmajai sodininkų bendrijai („Girios–7“) pritaikyta gyventojų sutankinimo koncepcija, antrajai sodininkų bendrijai („Kloniai“) – kelių ir inžinerinės infrastruktūros sutvarkymo koncepcija. Baigiamojo magistro darbo aiškinamojo rašto apimtis – 74 puslapių. Tekste panaudota 25 iliustracijos, 4 lentelės. Prieduose pateikiami Lietuvos statistikos departamento duomenys apie esamą Vilniaus rajono gyventojų skaičių ir sudėtį. Grafinę dalį sudaro du A1 formato brėžiniai – esamos būklės analizė ir pasiūlymai esamai būklei pagerinti.In this work the processes of gardeners’ communities converting into residential areas are investigated. This work focuses on communities located at Vilnius region. The goal of this work is to determinate if these communities function as independent settlements. Out of 261 gardeners’ communities, located in Vilnius region, two were selected (using the current state analysis): “Girios–7”, located in Bezdonių district, Zamečkavo village, and “Kloniai“, located in Nemėžio district, Pakalniškių village. In order to evaluate the functional and social needs of these communities, the chairmen were interviewed. According to the results of the interview, the suggestions to improve towards sustainable development were made: for the first gardeners’ community (“Girios–7”) population compacting concept was adapted; for the second gardeners’ community (“Kloniai“) - road and engineering infrastructure improvement concept. Size of explanatory notes of this Master thesis is X pages. 25 figures and 4 tables were used in the text. The data from department of statistics of Lithuania about current size and composition of the population in Vilnius region were given in appendixes. Graphic part of this work consists of two A1 format drawings: current state analysis and suggestions to improve the situation
Traffic safety analysis based on geospatial classification of streets
No full text“Traffic safety analysis based on geospatial classification of streets” is the solution proposed and developed by the Author to show that it is possible to analyse road and traffic safety by using geospatial and open source data as well as tools offered by ArcGIS software. The result of the Master’s thesis is a WEB based application created in the ArcGIS Online platform. The application is available under the link: https://ej.uz/on69 The developed application contains a published map of road accidents, which includes and displays the classification of road sections depending on the analysis of road accident points. Several traffic safety strategies that are implemented in other countries ha ve been studied as well, and some of the points the Author is recommending to consider for Latvian safe roads policy. Authors have developed this work with the vision Safe Roads, by offering this solut ion to the authorities responsible for road safety as a daily work tool, therefore supporting decision making on road safety improvement. The tool is designed to enable the relevant authorities to make decisions by following the principle “value for money” Structure: introduction, theory practical part, results, conclusions and suggestions, references Theses consist of: 86 p. text without appendixes, 47 pictures, 6 tables, 39 bibliographical entries. Appendixes included.“Traffic safety analysis based on geospatial classification of streets” is the solution proposed and developed by the Author to show that it is possible to analyse road and traffic safety by using geospatial and open source data as well as tools offered by ArcGIS software. The result of the Master’s thesis is a WEB based application created in the ArcGIS Online platform. The application is available under the link: https://ej.uz/on69 The developed application contains a published map of road accidents, which includes and displays the classification of road sections depending on the analysis of road accident points. Several traffic safety strategies that are implemented in other countries ha ve been studied as well, and some of the points the Author is recommending to consider for Latvian safe roads policy. Authors have developed this work with the vision Safe Roads, by offering this solut ion to the authorities responsible for road safety as a daily work tool, therefore supporting decision making on road safety improvement. The tool is designed to enable the relevant authorities to make decisions by following the principle “value for money” Structure: introduction, theory practical part, results, conclusions and suggestions, references Theses consist of: 86 p. text without appendixes, 47 pictures, 6 tables, 39 bibliographical entries. Appendixes included
Biblioteka informuoja, 2023 Nr. 36 (628)
No full textNaujai į Web of Science ir Scopus įtrauktų Vilnius Gedimino technikos darbuotojų publikacijų sąrašai ir kitos bibliotekos aktualijos.36 (628)202
Rod-shaped linear inertial type piezoelectric actuator
No full textThis article presents a numerical and experimental investigation of a novel rod-shaped linear piezoelectric actuator that consists of a square cross-section-shaped rod with eight piezo ceramic plates and a cylindrical guidance rail. The rod has a hollow cut made with an offset from the longitudinal axis of the symmetry. A cylindrical guidance rail is placed on one side of the rod, while T-shaped clamping is formed on the opposite side. The slider is mounted on the rail and is moved along it. The actuator is compact, making it possible to mount it directly on a printed circuit board (PCB) or in another device with limited mounting space, restricted mass, or actuator footprint. The operation of the actuator is based on the excitation of the first longitudinal vibration mode of the rod that induces in-plane bending vibration of the nodal zone of the rod due to a hollowed cut asymmetrically placed in the central part of the actuator. The actuator is driven by two sawtooth waveform electric signals with the phase difference of π that allows exciting longitudinal deformations of the rod and controls the reverse motion of the slider. The results of numerical investigations confirmed the operation principle of the actuator at the frequency of 59.72 kHz. The maximum displacement amplitude of the guidance rail in the longitudinal direction reaches up to 152.9 µm while the voltage of 200 Vp-p was applied. An experimental investigation of the actuator was made, and a maximum linear speed of 45.6 mm/s and thrust force of 115.4 mN was achieved.iss. 10vol. 1
Scenario modeling to predict changes in land use/cover using Land Change Modeler and InVEST model: a case study of Karaj Metropolis, Iran
No full textModels for land cover/land use simulation are appropriate and important tools for decision-makers, helping them build future plausible landscape scenarios. Due to the fact that the simulation results of different models may be different, it is sometimes difficult for users to choose a suitable model. Therefore, in this study, an integrated approach is used, combining the data obtained from remote sensing and GIS with Land Change Modeler (LCM) and Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models to simulate and predict land cover/land use changes for 2028 in Karaj metropolis (Northern Iran as a poor region—in terms of data—which is under intense and rapid urbanization. In this sense, three land cover/land use maps related to the study area were primarily generated using satellite image data for the period 2006, 2011, and 2017. They were used as a basis to define two scenarios: business-as-usual (BAU) scenario and participatory plausible scenario (PPS) for 2028. Afterwards, the necessary input data used in running of both models were prepared and, then, the outputs of the models were interpreted and compared. According to the results, while human-made coverage and low-density grasslands increased by about 74% and 12%, respectively, it was from 2006 to 2017 that agricultural lands, gardens, and high-density grasslands decreased by 42%, 34%, and 7%, respectively. According to the business-as-usual scenario, which was projected using the LCM model, the increase in human-made cover will continue by about 29% by 2028, and the reduction rate of agricultural lands, gardens, and low-dense and dense grasslands will experience decrease by about 20%, 3%, 11%, and 9%, respectively. The participatory plausible scenario for 2028, which was defined using the InVEST model, confirmed the same results, but having different quantities. Accordingly, while human-made cover will increase by about 73%, the reduction rate of agricultural lands, gardens, and low-dense and dense grasslands will decrease by about 41%, 10%, 16%, and 1%, respectively. The output quantities of InVEST scenario model seem to be closer to reality with less uncertainty, because this model estimates the quantity of demand for land and its suitability for different uses, based on the views of different stakeholders, and considers landscape development future policies and plans. In contrast, the LCM model is based solely on trend extrapolation from the past to current time and changes in the landscape structure.iss. 2vol. 19
The impact of buffer tank on coagulation / flocculation of industrial wastewater
No full textGamybinių nuotekų, sudėtis ir srautas per parą labai netolygūs, dėl šios priežasties prieš flotatorius paprastai įrengiamos išlyginamosios talpos. Pasak įmonės „EKOTON“ specialistų, rekomenduojama nuotekų išbuvimo išlyginamosiose talpose, kur jos nuolat maišomos maišykle, trukmė – 2–4 valandos. Tačiau realiai pasitaiko atvejų, kai į flotatorių tiekiamos nuotekos, neišbuvusios išlyginamojoje talpoje net minimalaus rekomenduojamo laiko, dėl to pastebimai suprastėja nuotekų išvalymo efektyvumas flotatoriuje. Eksperimentų metu tam tikrais laiko intervalais imti nuotekų mėginiai iš dviejų reaktorių, imituojančių maišomą ir aeruojamą išlyginamąsias talpas. Mėginiai buvo koaguliuojami / flokuliuojami, taip imituojant pirmąjį flotacijos proceso etapą, ir po to analizuojami pagal ChDS, BDS7, NH4-N, NO2-N, NO3-N ir PO4-P koncentracijas. Organinių medžiagų koncentracijos po koaguliacijos / flokuliacijos mažėjo ilgėjant nuotekų išbuvimo reaktoriuose trukmei: po pirmos valandos ChDS koncentracija abiejuose reaktoriuose sumažėjo 75 %, o po 8 valandų pradinė ChDS koncentracija maišomame reaktoriuje sumažėjo 83 %, aeruojamame – 88 %. Azoto ir fosforo junginių atveju išbuvimo trukmė reaktoriuje ir reaktoriaus tipas neturėjo įtakos šių junginių koaguliacijos / flokuliacijos efektyvumui.The composition and flow of industrial wastewater are very uneven, for this reason, buffer tank is usually installed before flotation unit. Recommended hydraulic retention time in a buffer tank is 2-4 hours while constantly stirring. However, in reality, sometimes fresh wastewater is fed directly to flotation unit, in this case, removal efficiency of pollutant is substantially reduced. During the experiment, samples were taken at a certain time intervals and concentrations of pollutants (COD, BOD7, NO2-N, NO3-N, NH4-N and PO4-P) were measured. After coagulation / flocculation organic material concentrations in reactors decreased with retention time: after the first hour COD concentration in both reactors decreased by 75 % and after 8 hours initial COD concentration in mixing reactor decreased by 83 %, in aerated reactor – 88 %. Retention time in reactors had no impact for nitrogen and phosphorus compounds coagulation / flocculation efficiency
Intrusion Detection by Analyzing Computer-level log Entries from the AWSCTD Dataset
No full textMagistro baigiamojo darbo tikslas – pasiūlyti įsibrovimo aptikimo būdą kompiuterio lygmenyje, paremtą žurnalinių įrašų analize. Atliekant literatūros analizę apžvelgiamos įsibrovimo aptikimo sistemos – jų tipai, naudojami metodai įsibrovimams aptikti. Detaliai analizuojamos kompiuterio lygmenyje veikiančios įsibrovimo aptikimo sistemos – nagrinėjama, kokias technikas bei kokius duomenis jos naudoja. Taip pat apžvelgiami įsibrovimo aptikimo tyrimuose, kompiuterio lygmenyje, naudojami duomenų rinkiniai ir metodai taikomi žurnalinių įrašų analizei. Tiriamojoje darbo dalyje apžvelgiamas AWSCTD duomenų rinkinys, aprašomi įžvelgti trūkumai bei apibūdinamas metodas taikomas duomenų rinkiniui papildyti. Taip pat aprašomas siūlomas metodas programų elgsenos duomenims atvaizduoti ir vektorizuoti. Galiausiai aprašomas atliktas bandymas aptinkant įsibrovimus ir apžvelgiami gauti rezultatai. Darbą sudaro 5 dalys: įvadas, susijusios literatūros analizė, siūlomo metodo aprašymas, išvados, literatūros sąrašas. Darbo apimtis – 83 p. teksto be priedų, 35 iliustr., 15 lent., 59 bibliografiniai šaltiniai.The objective of the Master's thesis is to propose an intrusion detection method at the computer level based on the analysis of logs. Through a literature analysis, the paper gives an overview of intrusion detection systems - their types and methods used to detect intrusions. A detailed analysis of host-based intrusion detection systems is performed, where the techniques and type of data used were examined. It also covers the datasets used in host-based intrusion detection research and the methods used to analyze log records. The exploratory part of the thesis gives an overview of the AWSCTD dataset, describes the shortcomings identified, and describes the method used to augment the dataset. It also describes the proposed method for representing and vectorizing behavioral data of the executed programs. Finally, the intrusion detection experiment is described, and the results obtained are summarized. The thesis consists of 5 parts: introduction, analysis of related literature, description of the proposed method, conclusions, list of references. The volume of the thesis is 83 pages of text without appendices, 35 illustrations, 15 tables, 59 references
Hydrogen or electric drive—inconvenient (omitted) aspects
No full textCurrently, hydrogen and electric drives used in various means of transport is a leading topic in many respects. This article discusses the most important aspects of the operation of vehicles with electric drives (passenger cars) and hydrogen drives. In both cases, the official reason for using both drives is the possibility of independence from fossil fuel supplies, especially oil. The desire for independence is mainly dictated by political considerations. This article discusses the acquisition of basic raw materials for the construction of lithium-ion batteries in electric cars, as well as methods for obtaining hydrogen as a fuel. The widespread use of electric passenger cars requires the construction of a network of charging stations. This article shows that, taking into account the entire production process of electric cars, including lithium-ion batteries, the argument that they are ecological cannot be used. Additionally, it was indicated that there is no concept for the use of used accumulator batteries. If hydrogen drives are used in trains, there is no need to build the traction network infrastructure and then continuously monitor its technical condition and perform the necessary repairs. Of course, the necessary hydrogen tanks must be built, but there must be similar tanks to store oil for diesel locomotives. This paper also deals with other possibilities of hydrogen application for transformational usage, e.g., the use of combustion engines driven with liquid hydrogen. Unfortunately, an optimistic approach to this issue does not allow for a critical view of the whole matter. In public discussion, there is no room for scientific arguments and emotions to dominate.iss. 11vol. 1