Experimental and Analytical Study on Local Buckling Behavior of the Concrete-filled Thin-walled Welded Steel Columns

This paper presents an experimental investigation of the concrete filled thin-walled welded steel tubes. Square and rectangular columns are tested with and without the bond between the steel profile and concrete. In order to remove the bond in the latter columns a polyethylene (PE) film is placed inside of the steel profiles. Experimental results are verified via the finite element analysis and compared to the results obtained using the analytical calculation methods. The significance of the steel–concrete bond is evaluated, referring to the differences of the critical loads, ultimate loads and effective cross-sectional areas of the columns with and without the PE film inside and the differences are found to be considerable. It is found that the columns without the film had an up to 47 % higher effective cross-sectional area to full cross-sectional area ratio. The average reduction of the effective cross-sectional area of the column having a poor bond is found to be 12 %. It is also found that the resistance is often overestimated when using the analytical formulas, especially for the columns with the PE film inside

Studijų kokybės užtikrinimas fakultete: universitetinių ekonomikos studijų patirtis

The purpose of studies is to provide sufficient application fundamentals of theoretical and practical knowledge, cultivate certain future specialist abilities to ensure the preparation level needed at work. Measurements on quality of studies as well as the study quality assurance are commendable and encouraged, such as the strive towards the ideal study process, superb education, good and prestigious studies, etc. The students’ level of knowledge and professional preparation adequacy to the international requirements, conversely, remarks on quality of studies can always be proclaimed.The internal quality of study evaluation and securitization systems implemented or in the process of implementation in the number of Lithuanian higher education institutions or universities, have gained recognition. These systems are based on standard application of ISO 9001 quality management system, main advantage is recognition of management ability for quality of study process in the division.The Quality management system was designed and the process of implementation in the Faculty of Economics proceeded including different aspects. Main consideration is given to the description of quality of studies at Vilnius University Faculty of Economics, assessed by means of abundant students’ survey data.The survey result processing system gives an opportunity to obtain a thorough view of the study process in respect to teaching and subject quality, popularity, discipline, the level of the taught subjects and obtained useful information on relevant study questions.The obtained results for the quality of studies and quality management system utilization in Vilnius University Faculty of Economics are presented in more details, and the perspectives of the process are foreseen.Profesorė socialinių mokslų daktarė (HP)Vilniaus universitetoEkonominės politikos katedraSaulėtekio al. 9, II rūmai, 411 k.LTLT-10222 VilniusEl. paštas: [email protected] socialinių mokslų daktarasVilniaus universitetoKiekybinių metodų ir modeliavimo katedraSaulėtekio al. 9, II rūmai, 404 k.LTLT-10222VilniusEl. paštas: [email protected] nagrinėjami studijų proceso vertinimo ir palaikymo metodiniai ir praktiniai aspektai. Pagrindinis dėmesys skiriamas Vilniaus universiteto Ekonomikos fakulteto studijų kokybei apibūdinti naudojant studentų apklausas apie dėstymo, studijų programų kokybę. Aptariama kokybės vadybos sistemos diegimo šiame fakultete patirtis ir perspektyvos

NATIONAL WEALTH ASSESSMENT AND UTILIZATION IN TRANSITION ECONOMIES

The economy’s power and capacities could be measured using different methodologies and numerous macroindicators. The national wealth definition provides an opportunity to reveal not only accumulated resources, but also exposes a real potential of the country and the path for sustainable development. Wealth measurements for transition countries could show the long term development rationality, comparing national wealth structure and its components for different countries. The two methodologies – National Accounts System and World Bank Measuring of wealth, and the obtained comparison results are discussed in the paper

Structural and transport property changes in austenitic stainless steel induced by nitrogen incorporation

The saturation of the near surface layers of metals with different elements is a powerful tool to change their surface properties. In this work, structure and transport changes induced by incorporation of large amounts of nitrogen at moderate temperatures (∼370−430°C) in austenitic stainless steel are investigated. The structural study of the plasma nitrided ASS has been carried out using a combination of global (X-ray diffraction, nuclear reaction analysis) and local probe techniques (Mossbauer, X-ray absorption near edge structure, extended X-ray absorption fine structure spectroscopies). It reveals that nitriding at moderate temperatures (∼400°C) results in the nitrided layer with Fe, Cr and Ni being in different local chemical environments: Cr in the CrN-like state, Fe in the Fe4N-like state, Ni in the metallic state. The results demonstrate that the incorporation of interstitial nitrogen destabilizes homogeneous distribution of the ASS constituents, which leads to the segregation of the elements into small zones rich in Cr and Ni and provide strong evidence that the decomposition is of a spinodal nature. These experimental findings contradict the widely accepted view that the phase formed during nitriding at moderate temperatures is a homogeneous supersaturated nitrogen solid solution. The nitrogen atomic transport study has been carried out by using ion beam nitriding of single-crystalline stainless steel, and the issues of the influence of the crystalline orientation, nitriding temperature, ion flux and ion energy are addressed. The diffusion coefficients have been extracted from the fitting of the nitrogen depth profiles by using the trapping-detrapping model. It is shown that the crystalline orientation plays a significant role in nitrogen diffusion: the penetration depth is largest, intermediate and lowest for the (001), (110) and (111) orientation, respectively. The pre-exponential factor D0 varies by two orders of magnitude depending on the orientation, while the activation energy E is similar (∼1.1 eV) for the (111) and (110) orientations and higher for the (001) orientation (∼1.4 eV). It is found that the nitrogen ion energy and the flux have the effect on the nitrogen transport in the bulk with higher energies (or fluxes) showing larger diffusion coefficients. The ion energy effect is more pronounced for the (001) than for the (111) orientation, while the flux effect is similar in both orientations. In addition, the diffusivity during post-nitriding thermal annealing without ion irradiation is found to be independent of the crystalline orientation. The observed radiation enhanced diffusion and anisotropy are discussed on the basis of nitrogen incorporation induced changes in the matrix structure (ASS decomposition and formation heterogeneous structure), ion bombardment induced effects (defects, localized vibrations) and correlated diffusion

Prekybos srities specialistų VU Ekonomikos fakultete rengimas ir jų atitikimas rinkos poreikiams

This research is dedicated to analysing the development of preparation process of trade specialists at Vilnius University. Highest focus is laid on the period after the restoration of Lithuanian’s independence. Statistical analysis covering dynamics and scope of trade graduates from Trade faculty and later Economics faculty is performed. While revealing aims of study programmes and their achievement through development of generic and subject specific competencies, peculiarities of preparing trade specialists at bachelor and master levels are presented. Qualitative valuation of study programmes aimed at preparing trade specialists, their development and correspondence to market needs is performed employing massive survey data.Straipsnis skirtas prekybos specialistų rengimo Vilniaus universitete raidos analizei, pagrindinį dėmesį skiriant jų rengimui, atkūrus Lietuvos nepriklausomybę. Atlikta prekybos specialistų Ekonomikos fakultete išleidimo statistinė analizė, įvertinama specialistų rengimo dinamika ir apimtys per nagrinėjamą laikotarpį. Pateikiami prekybos specialistų rengimo bakalauro ir magistro pakopose ypatumai, išryškinami studijų programų tikslai bei jų siekimo keliai per bendrųjų ir specialiųjų kompetencijų ugdymą. Prekybos srities studijų programų vykdymas, šios srities specialistų rengimas bei rinkos poreikių atitikimas kiekybiškai vertinami, naudojant gausių anketinių apklausų duomenis bei atitinkamai apdorotą informaciją

Informal education organization improvement in order to meet students’ needs

Šiuolaikinės demokratinės visuomenės kūrimo vienas iš svarbiausių veiksnių – vertybių ugdymas. Neformalusis papildomas ugdymas yra neatsiejama viso ugdymo proceso dalis, nes moksleivių ugdymas apima mokymą(si), lavinimą(si), auklėjimą(si). Jis taip pat padeda atskleisti prigimtinius moksleivių gabumus, vysto kūrybines galias. Atlikto tyrimo tikslas – ištirti Utenos rajono bendrojo lavinimo mokyklų neformaliojo ugdymo ypatumus ir prielaidas šiai veiklai tobulinti. Tyrimo problema – kaip tobulinti neformalųjį ugdymą, siekiant kuo geriau patenkinti skirtingus mokinių poreikius. Tuo tikslu išanalizuota mokslinė pedagoginė, psichologinė, vadybinė literatūra ir teisiniai dokumentai, atliktas empirinis tyrimas naudojant anketinės apklausos metodą. Tyrimo imtis – 568 respondentai, iš jų: 15 mokyklų vadovų, 68 klasių auklėtojai, 394 mokiniai, 91 būrelio vadovas. Tyrimo rezultatai parodė, kad bendrojo lavinimo mokyklų vadovai, klasių auklėtojai skiria didelį dėmesį mokinių neformaliajam ugdymui: mokyklose veikia daug ir įvairių būrelių, siekiama įtraukti į jų veiklą kuo daugiau mokinių. Tačiau darbą su mokiniais apsunkina kai kurios problemos: nepakankama mokyklų materialinė bazė, mokykloms trūksta ir būrelių rėmėjų, mažai būrelių užsiėmimams skiriama valandų. Remiantis tyrimo duomenimis, parengtos išsamios išvados ir rekomendacijosOne of the key factors of modern democratic society is values education. Non-formal additional education is an integral part of total educational process because it includes (self) teaching, (self)education, (self)improvement. It also helps to reveal the inherent talents of students, to foster creativity. Objective of the research is to analyse features and assumptions of non-formal education to improve it in Utena district secondary schools. Problem of the research is how to develop non-formal education, so as to better meet the needs of different students. To this end, the scientific pedagogical, psychological, managerial literature and juridical documents were analysed, an empirical study using a questionnaire survey method was done. In a survey - 568 respondents, of whom: 15 school principals, 68 school teachers, 394 students, 91 after-school club leaders. The results showed that secondary school heads and teachers attach great importance to non-formal students' education: there are a lot of different after-school clubs, it is intended to incorporate into its activities as more students as possible. However, there are some difficult problems: lack of school material and financial resources, lack of sponsors and hours for after-school clubs. According to the survey the detailed findings and recommendations were prepared.Švietimo akademijaVytauto Didžiojo universiteta

Biudžetų kontrolės problemos Lietuvos įmonėse

Nestabilioje rinkos aplinkoje kiekvienos įmonės veikla labai priklauso nuo taikomos veiklos planavimo ir kontrolės sistemos. Svarbi sudėtinė įmonių planavimo ir valdymo sistemos dalis yra biudžetai. Biudžetas yra strateginio (ilgalaikio) plano dalies, dažniausiai vieneriems metams, detalizavimas, stengiantis tiksliai pateikti veiklos tikslus ir resursus jiems pasiekti. Grįžtamojo tyšio funkciją šioje sistemoje atlieka biudžeto vykdymo kontrolė, kuri yra įmonės veiklos ir finansinės būklės monitoringas, įgalinantis vertinti pasiektus rezultatus, koreguoti veiksmus, motyvuoti darbuotojus. Straipsnyje svarbiausias dėmesys skiriamas biudžetų kontrolės koncepcijos pagrindimui, biudžetų kontrolės privalumų analizei, biudžetų kontrolės etapo klaidų Lietuvos įmonėse analizei ir vertinimui, galimai šių klaidų prevencijai. Biudžetų kontrolės klaidų išvengimas leistų įmonėms geriau suderinti veiklos procesus, racionaliau paskirstyti finansinius, materialinius bei darbo išteklius, ryšius tarp įmonės padalinių ir jų vadybininkų. Tai ypač svarbu ekonominio nestabilumo metu, kai rinkoje išauga neapibrėžtumai ir žymiai padidėja rizika. Teoriniu požiūriu biudžeto vykdymo kontrolė nėra sudėtinga, problemos kyla metodiką realizuojant praktikoje. Metodinės problemos pakankamai gerai formalizuojamos, tačiau dažnai neaišku, kaip tai priversti dirbti realiame laike ir įmonės vertybių grandinėje. Didele dalimi biudžetų kontrolės efektyvumą lemia įmonės vadovybės ir darbuotojų organizaciniai gebėjimai bei efektyvi stimuliavimo sistema.The article deals with an important management and control tool — budgetary control - in Lithuanian enterprises. While commonly recognized and widely applied in advanced economies, this managerial accounting area is scarcely discussed in Lithuanian economic literature and faces considerable challenges and mistakes regarding attitude, acceptance and application. The main focus is brought on the concepts and advantages of budgetary control, analysis and assessment of the budgetary control errors in Lithuanian companies including potential prevention of these errors. Prevention of the budgetary control mistakes will allow companies to better align business processes, allocate financial, capital and labour resources more rationally, and improve relationships between company departments and their management. This is especially important in the period of economic instability when market uncertainty and risk significantly increases