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Journal ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA

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37 articles
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Opeyemi Shoaga, Folorunso Ajasa, Sesan Olatunde Mabekoje
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 3, pp 28-39; doi:10.29114/ajtuv.vol3.iss1.115

Abstract:This study investigated the effect of three play strategies on academic performance of low achiev-ing Basic 1 pupils in primary schools in Oyo State, Nigeria. A quasi-experimental research design using pretest, posttest, control group was adopted where pupils screened to have low achievement scores were selected from schools randomly assigned to treatment groups. Participants met on dif-ferent treatment strategies for eight weeks of two contact hours each. Academic performance was assessed before and after treatment with data analysed using Analysis of Covariance. Results in-dicated that the three play strategies are effective in improving pupils’ academic performance (F (3 124) = 310.566; p
Iliyan Velichkov Iliev
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 3, pp 40-53; doi:10.29114/ajtuv.vol3.iss1.121

Abstract:< p align="justify">The current study presents the results from the experimental research conducted on the influence of the regime parameters on the process for a five-dimensional Ball Burnishing (BB) finishing process with the help of a CNC milling machine on the Regular Reliefs (RR) obtained on complex functional surfaces. The elements of the technological system, necessary for the formation of RR of type IV on the complex surfaces, are presented. A planned factorial experiment is realized, through which the significantly affecting parameters of the BB process on the size and shape of the RR cells, are determined. The results obtained are statistically confirmed by a dispersion analysis (ANOVA) carried out. Conclusions, regarding the possibilities of obtaining RRs of type IV on complex surfaces through a process of five-axis simultaneous BB, are made.
Opeyemi Olumayowa Shoaga, Simidele Rasheed
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 3, pp 21-27; doi:10.29114/ajtuv.vol3.iss1.120

Abstract:The study examined the influence of socio-economic variables (parents’ income and parents’ educational background) and parental involvement on academic performance of pupils. The survey research design was adopted for the purpose of this study. A sample of 200 pupils in primary four was randomly selected from 10 basic schools for the study. Three research questions were raised and tested for the study. Data were collected using Questionnaire. Data were analysed using Analysis of Variance and Pearson Product Moment Correlation statistics. Significant difference existed in the academic performance of pupils based on their parents’ income while no significant difference existed in the academic performance of pupils based on their parents’ educational background. Furthermore, significant positive relationship was observed between parental involvement and academic performance of pupils. Findings of this study recommends among others that schools managers should develop intervention programmes aimed at addressing the strategies that will help the improvement of the quality and consistency of parental involvement in their children’s education activities if they anticipate better academic performance.
Abolaji Olugbenga Bukki, Yekinni Abiodun Oguntimehin, 'Muyiwa Adeyemi
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 3, pp 1-10; doi:10.29114/ajtuv.vol3.iss1.109

Abstract:This study examined resource mobilisation and innovative culture of small and medium-scale enterprises (SMEs) owners in South-West, Nigeria. Five research questions were raised. The study adopted the descriptive survey research design. The sample comprised one thousand, four hundred and seventeen (1417) SME owners / managers out of which one thousand, three hundred and eighty-two (1382) responded appropriately, this showed 97% response rate. Data were collected using two instruments; these are Resource Mobilisation Questionnaire (r = 0.85) and Innovative Culture Scale (r = 0.68). Data were analysed using descriptive statistics, Pearson Product Moment Correlation and Independent t test.The results showed that SME owners possessed high level of resource mobilisation and innovative culturein South-West, Nigeria. Significant relationship existed between resource mobilisation and innovative culture of SME Owners’ in South-West, Nigeria. Furthermore, there was significant difference in the score on resource mobilisation of SME Owners while no significant difference existed in the score on innovative culture of SME Owners in South-West, Nigeria. Based on the findings, it was recommended among others that Government agencies should create strategies to improve resource mobilisation. This, in turn, will upgrade and enhance innovation among SMEs.
Razaq Olugbenga Azeez
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 3, pp 11-20; doi:10.29114/ajtuv.vol3.iss1.113

Abstract:This study investigated the effect of emotional intelligence training programme on emotional labour competence of social workers. The study adopted a pretest-post-test quasi-experimental design. The emotional labour scale was used to collect data from the forty-eight (48) randomly selected social workers from two Non-Governmental Organizations (NGOs). Participants of the study were randomly assigned to the treatment and the control groups for the purpose of the study. The hypothesis was tested using the Analysis of Covariant (ANCOVA). Results showed that the treatment significantly affected participants' levels of emotional labour. Based on the findings, it was advocated that the teaching of emotional intelligence in organizations and schools is highly important for optimal outcomes.
Anastas Todorov Yangyozov, Damjanka Stojanova Dimitrova, Lazar Georgiev Panayotov
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 2, pp 70-79; doi:10.29114/ajtuv.vol2.iss2.95

Abstract:A small turbine, working with air and water to generate electricity, was designed and its performance was reported in this paper. The rotor diameter is 150mm. The numerical calculations of the power coefficient, torque, and tip speed ratio of turbine were carried out for a wide range of inlet velocities. The flow passing through the turbine was investigated with commercial CFD code ANSYS CFX 18
Maciej Sulowski, Ewa Lichańska, Paweł Kulecki, Monika Tenerowicz-Żaba, Anna Staniek
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 2, pp 1-13; doi:10.29114/ajtuv.vol2.iss2.79

Abstract:Sintering behavior in high purity nitrogen and mixture of 5% H2-95% N2 of Fe-(Cr)-(Mo)-C system was investigated. The mixtures, differ from chromium, molybdenum and carbon content were prepared in Turbula mixer. Then, using single-action pressing in a rigid die at pressing pressure 400 MPa, green compacts with density level 5.9±0.17 g/cm3 were pressed. Sintering was carried out in a horizontal push rod dilatometer Netzsch 402E at 1120 and 1250°C for 60 min. Heating and cooling rates were 10 and 20°C/min., respectively. After heating, compacts were isothermal sintered at 1120 or 1250°C for 60 minutes an cooled up to 200°C, then isothermally hold for 60 minutes and definitely cooled to the room temperature. Pure nitrogen and mixture of 5% H2-95% N2 were employed as sintering atmospheres. During investigations the influence of isothermal sintering temperature, chemical composition of sintering atmosphere, chromium, molybdenum and carbon content was followed by dilatometry. The aim of investigations was to determine transformation temperatures. It was shown that the dimensional changes occurring during heating and isothermal sintering and the final density of sintered compacts are influenced by sintering parameters and the alloying elements concentration in powder mixture.
Nadezhda Ognjanova Doseva, Daniela Chakyrova
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 2, pp 62-69; doi:10.29114/ajtuv.vol2.iss2.94

Abstract:This paper considers the questions of techno-economic optimization in order to determine the thermal transmittance coefficient of the external walls of an existing residential building.The optimization procedure is conducted for the climatic and economic conditions in Bulgaria and taking into account the existing legal framework. The minimum of the building life cycle costs is determined by using genetic algorithm
Momchil Todorov Tachev, Tihomir Atanassov Dovramadjiev, Ginka Velikova Jecheva, Kremena Cankova Markova
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 2, pp 54-61; doi:10.29114/ajtuv.vol2.iss2.93

Abstract:Bulgarian female folk costume is rich in multiple characters, elements and details. One of the most characteristic is the belt buckles. As well as specially designed symbolism, the belt buckle - with their unique identity belong to the national - historical heritage of Bulgaria. In the present study a model of a belt buckle is digitized and reconstructed, and possessing grace and beauty. The realization of the completed three-dimensional computer model goes through stages of photogrammetry and computer design with special sculpting tools.
Hristina Vasileva Tacheva, Tsena Radkova Murzova
ANNUAL JOURNAL OF TECHNICAL UNIVERSITY OF VARNA, BULGARIA, Volume 2, pp 80-86; doi:10.29114/ajtuv.vol2.iss2.100

Abstract:The digital image is an integral part of the contemporary design process. Regardless of the method used to create the image of a conceptual idea /sketch, esquisse/. The result is a digital image, which permits manufacturing, modification and printing. In the design for academic purposes such cases are the majority. This research examines the possibilities for the specific application of 3D scanning in the design of specific complex forms with volume with an artistic character in the field of the award and memorabilia academic system. The application of these technologies noticeably decreases the time needed for design, which is key in such tasks. There is an increase in the precision of the manufacturing of the specific form, as well as a possibility for its printing and modification should the need of other projects, demanding the presence of the same object arise.
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