Development of weld interpass temperature control system for Wire and Arc Additive Manufacturing

Pri aditivnih tehnologijah na osnovi oblikovnega obločnega navarjanja s klasičnimi MIG/MAG postopki, je varilna šoba pritrjena na industrijskega robota ali na CNC stroj, ki jo med navarjanjem po programu premika v 3D prostoru. Za doseganje ustrezne geometrije depozita, mora biti medvarkovna temperatura ustrezno nizka. S tem namenom je razvit krmilnik temperature, ki temelji na IR temperaturnem senzorju. CNC krmilnik je povezan z varilnim virom in krmilnikom temperature. Razvito je krmiljenje celotnega sistema. Za hitrejše ohlajanje objekta je dodan tudi elektromagnetni pnevmatski ventil, s katerim se avtomatsko vklaplja prisilno hlajenje s komprimiranim zrakom. Učinek hlajenja s komprimiranim zrakom je testiran z navarjevanjem ravnih sten. Učinkovit je predvsem pri izdelavi višjih objektov s kratkimi zvari oz. pri manjših izdelkih. Sistem je bil testiran tudi z izdelavo lupinskih objektov. Pri tem velik izziv predstavlja predvsem doseganje konsistentnih vžigov varilnega obloka. Izkaže se, da so nekonsistentni vžigi eden od glavnih dejavnikov za pojav napak na izdelku in za posledično odstopanje geometrije izdelka od predpisane.Wire and Arc Additive Manufacturing is a manufacturing process where welding torch is used together with a robot arm or other CNC manipulator to produce parts. During weld cladding, the torch is moved in 3D space according to the CNC program. To achieve a desired geometry of the weld bead when making small size parts, previously deposited weld has to be cooled down beneath a certain temperature. For that reason, temperature controller based on an IR thermometer was developed. Temperature controller and welding source communicate with the CNC controller, which is responsible for coordinated operation of the system. Custom control programs had to be developed. To remove excess heat from the welded part faster, automated cooling with compressed air was added to the system. Cooling effectiveness was evaluated by manufacturing multiple vertical walls. The results show that such cooling is especially effective when welding high parts with short welding trajectories. Welding system was also tested by welding different shell objects. It turns out that inconsistent ignitions of the welding arc can drastically effect the quality of the welded part. They are one of the main reasons for surface defects that also lead to deviations in the welded part geometry from the programmed geometry

Use of cold plasma for treatment of fruit juices

Uporaba različnih načinov pasterizacije sadnih sokov različno vpliva na kakovost sadnih sokov. S toplotno obdelavo se kakovost proizvodov lahko močno zmanjša, zato so poleg termične pasterizacije začeli uporabljati netermične metode. Eden izmed teh je uporaba hladne plazme s katero lahko zmanjšamo negativne posledice toplotne obdelave, kot so zmanjšanje hranilne vrednosti in poslabšanje senzoričnih lastnosti. Tretiranje s hladno plazmo v kratkem času (5 s) ne zmanjša vsebnosti vitamina C, lahko pa pride do zmanjšanja, ko čas obdelave podaljšamo (npr. 20 s). Vsebnost antocianinov v sadnem soku se po tretiranju le-tega s hladno plazmo spreminja glede na vrsto sadnega soka, npr. v soku granatnega jabolka so antocianini stabilni, v borovničevem soku se vsebnost močno zmanjša. Vsebnost polifenolov in flavonoidov se lahko poveča, pri predolgi izpostavljenosti pa lahko začnejo razpadati. Barva sadnih sokov se po obdelavi s hladno plazmo ne spreminja tako kot pri toplotni obdelavi, ko lahko nastanejo nezaželjeni rjavo obarvani pigmenti. Mikroorganizme lahko s hladno plazmo popolnoma inaktiviramo, vendar moramo pri tem upoštevati tudi kakovost sadnega soka in empirično določiti optimalne parametre obdelave. Pri obdelavi sadnega soka s hladno plazmo moramo upoštevati tlak, napetost, čas obdelave in vrsto plina ter te parametre prilagajati sadnim sokovom in željenim rezultatom.Application of different ways of fruit juice pasteurization might impact differently the quality of the products. As thermal processing can drastically diminish the quality of the product, alternative non-thermal means of pasteurization are being tested. One of them is cold plasma, which has no negative consequences on product nutritional and sensory quality. Cold plasma treatment used in a short period of time (5 s) does not diminish the content of vitamin C, although with an increase of the processing time (20 s) quality deterioration might take place. The stability of anthocyanins after the application of cold plasma depends on the type of fruit juice. The content of anthocyanins in pomegranate juice remains stable, while their content in blueberry juice diminishes considerably. The content of polyphenols and flavonoids can increase with the use of cold plasma, but might decompose if the exposure time is too long. The colour of fruit juices does not change after the application of cold plasma as it happens with thermal processing, where unwanted brown pigments form. Microorganisms can be completely inactivated with cold plasma but we also have to consider the quality of the product and empirically set optimal parameters. Pressure, tension, processing time and gas type are the parameters that must be taken into consideration and adjusted according to the type of juice and required results

Vloga in pomen izobraževanja svetovalcev zaposlitve na Zavodu Republike Slovenije za zaposlovanje

The changes in an external environment, especially within the labor market,encourage continuing education, not only those who want to acquire the additional skills for advancement in their career path or passage out of an unemployment situation but also the employment advisers. The latter communicate with an unemployed person and are able to perform their function properly only if they are proffesionally and personally mature. We want to present the current required advisers work in Slovenia on the basis of the field research, which was carried out for the preparation of the particular degree thesis. It is inevitable today that each individual is trained for both the professional and the career development as well for personal growth. Employment advisers are in continuous contact with unemployed. Their knowledge, skills and ultimately personal maturity, may be helpful for unemployed people which can be therefore successfully and effectively orient to the desired field of employment. The research has pointed out that it is necessary to expand the level of training for employment advisers. It makes sense to consider different employment roles and diversity of functions of the employees in order to develop various forms and methods of education for employment advisers, which includes also e-education.Spremembe zunanjega okolja, predvsem trga dela, spodbujajo k nenehnemu izobraževanju ne le tiste, ki si želijo pridobiti dodatnih znanj za napredovanje na svoji karierni poti ali preiti iz stanja brezposelnosti v zaposlenost, temveč tudi svetovalce zaposlitve. Slednji stopajo v komunikacijo z brezposelno osebo in funkcijo svetovanja lahko opravljajo primerno le, če so sami dovolj strokovno in osebnostno zreli za delovanje na trgu dela. S prispevkom želimo predstaviti aktualna potrebna znanja svetovalcev zaposlitve v Sloveniji na podlagi raziskave, ki je bila izvedena v okviru priprave določenega diplomskega dela. Danes je neizbežno, da se vsak posameznik izobražuje tako za strokovni kot karierni razvoj in da obenem gradi osebnostni razvoj. Svetovalci zaposlitve so v neprestanem stiku z brezposelnimi ljudmi. S svojimi znanji, sposobnostmi in nenazadnje svojo osebnostno zrelostjo so lahko brezposelnemu v veliko pomoč pri vrnitvi na trg dela in ga lahko uspešno ter učinkovito usmerijo v želeno področje zaposlitve. Z raziskavo smo ugotovili, da je potrebno predvsem razširiti ponudbo izobraževanj za svetovalce zaposlitve. Pri tem je smiselno upoštevati različno strukturo zaposlenih, različnost nalog zaposlenih in temu ustrezno oblikovati različne oblike in metode izobraževanja

Spatial and climatic characterization of three glacial stages in the Upper Krnica Valley, SE European Alps

The southeastern European Alps represent the spot where mean annual precipitation is at its highest in the entire Alpine chain. Accordingly, the glacial evolution here might have a different spatial and chronological pattern if compared with other alpine areas. This paper discusses geomorphological evidence of three glacial stages from the Krnica Valley in the Julian Alps of Slovenia, and is the first step towards a comprehensive palaeoglaciological studies in this alpine sector. Very well-preserved glacial landforms in the Upper Krnica Valley allowed the reconstruction of glacier surface topographies and corresponding equilibrium line altitudes (ELAs) by means of field-based geomorphological and sedimentological data and by using geospatial analysis. The uppermost frontal moraines belong to the Little Ice Age (LIA) and the corresponding ELA is estimated at 1973 m a.s.l. Other two stages with the ELA depressed by 50 m and 161 m compared to the LIA ELA, suggest early Holocene and Younger Dryas ages of the palaeoglaciers, respectively. This assumption ensues from absolute age datings and related ELA depressions observed elsewhere in the European Alps. The presence of buried ice under the debris in the Krnica cirque, imaged through geophysical investigations, point to peculiar microclimatic conditions able to preserve relict glacier ice. This is favoured by the recursive presence of snow on the ground caused by the extreme summer shading and the significant winter snow-recharge triggered by snowblow and avalanche feeding. The possible evolution of such relict ice under the ongoing climate warming is also discussed

Towards the Evaluation of Possible Indicators for the Provision of Green Spaces in Settlements to Promote Physical Activity among the Population

Publicly accessible and usable green spaces in cities and smaller settlements are important for promoting physical activity and consequently for maintaining and improving public health. Adequate provision of such spaces is crucial for planning of a quality living environment. Research to date has identified different aspects in linking public health and green spaces. However, the problems of existing approaches and methods include inconsistencies in evaluating different aspects of public spaces for physical activity, lack of inclusion of social and health benefits of green spaces in green space indicators, and lack of integrated approaches towards defining the provision of green spaces to promote physical activity. Accordingly, a solid spatially explicit indicator for assessing the provision of settlements with green spaces for physical activity is non-existent. The purpose of this paper is to present the literature review and methodological framework developed within the Slovenian research project titled Development of indicators for the assessment of the provision of settlements with green spaces for outdoor physical activity that addresses aspects of public green spaces and related indicators for assessing the adequacy of the conditions provided by urban green spaces for different types of physical activity. We have defined three basic types of physical activity, namely: activities that are carried out in one place, activities that cover distance for leisure of recreation, and activities that cover distance to reach a goal (i.e., daily active mobility). Guided by this definition, we conducted a literature review to examine: (1) which spatial aspects of enabling or promoting physical activity are addressed by existing green space indicators, (2) to which spatial scale and to which spatial planning levels are indicators linked and, (3) whether indicators address different types of physical activity. Based on the findings, suggestions are made to develop a more spatially explicit indicator to assess the provision of green spaces in settlements for the three types of physical activity. Such an indicator can strengthen the long-term monitoring of the condition of publicly accessible green spaces for recreational use by the population

Different standards: engineers’ expectations and listener adoption of digital and FM radio broadcasting

As digital radio broadcasting enters its third decade of operation, few would argue that it has met all expectations expressed at the time of its launch in the mid-1990s. Observers are now more circumspect, with views divided on the pace of transition to an all-digital future. In exploring this mismatch between expectation and actuality, this article considers the introduction of FM radio from the 1950s. It too was expected to replace its forebear (AM) but, like digital radio, its adoption by listeners was slower than anticipated. An examination of published literature, in particular engineering and technical documents, reveals a number of similarities in the development of digital radio and FM. Assumptions about listeners’ needs and preferences appear to have been based on little actual audience research and, with continual reference in the literature to the supposed deficiencies of the predecessor technology, suggest an emphasis in decision making on the technical qualities of radio broadcasting over an appreciation of actual audience preferences

Visual inspection system for anomaly detection on KTL coatings using variational autoencoders

Electric cathode metal coating (KTL) is a popular choice for surface protection of metal components in the automotive industry. Due to the complex 3D shape of the parts and the glossy black color of the coating, machine vision inspection is very sensitive to variabilities among parts and to the variabilities in their positioning during the image acquisition. In this paper a variational autoencoder model for anomaly detection is presented to make further image processing more immune to variability and to detect coating defects more reliably

Employment risk, unemployment insurance and search strategies: a disaggregated equilibrium approach with application to the Swiss labour market in the 1990-ies

The Organization of the Thesis The remainder of the thesis comprises five chapters and a conclusion. The next chapter formalizes the envisioned theory into a tractable model. Section 2.2 presents a formal description of the model economy: the individual heterogeneity, the individual objective, the UI setting, the population dynamics and the equilibrium. The welfare and efficiency criteria for qualifying various equilibrium outcomes are proposed in section 2.3. The fourth section shows how the model-generated information can be computed. Chapter 3 transposes the model from chapter 2 in conditions that enable its use in the analysis of individual labor market strategies and their implications for the labor market equilibrium. In section 3.2 the Swiss labor market data sets, stylized facts, and the UI system are presented. The third section outlines and motivates the parameterization method. In section 3.4 the model's replication ability is evaluated and some aspects of the parameter choice are discussed. Numerical solution issues can be found in the appendix. Chapter 4 examines the determinants of search-strategic behavior in the model economy and its implications for the labor market aggregates. In section 4.2, the unemployment duration distribution is examined and related to search strategies. Section 4.3 shows how the search- strategic behavior is influenced by the UI eligibility and section 4.4 how it is determined by individual heterogeneity. The composition effects generated by search strategies in labor market aggregates are examined in section 4.5. The last section evaluates the model's replication of empirical unemployment escape frequencies reported in Sheldon [67]. Chapter 5 applies the model economy to examine the effects on the labor market equilibrium of shocks to the labor market risk structure, to the deep underlying labor market structure and to the UI setting. Section 5.2 examines the effects of the labor market risk structure on the labor market equilibrium and the labor market strategic behavior. The effects of alterations in the labor market deep economic structural parameters, i.e. individual preferences and production technology, are shown in Section 5.3. Finally, the UI setting impacts on the labor market are studied in Section 5.4. This section also evaluates the role of the UI authority monitoring and the differences in the Way changes in the replacement rate and the UI benefit duration affect the labor market. In chapter 6 the model economy is applied in counterfactual experiments to assess several aspects of the Swiss labor market movements in the nineties. Section 6.2 examines the two equilibria characterizing the Swiss labor market in the nineties, the " growth" equilibrium with a "moderate" UI regime and the "recession" equilibrium with a more "generous" UI. Section 6.3 evaluates the isolated effects of the structural shocks, while the isolated effects of the UI reforms are analyzed in section 6.4. Particular dimensions of the UI reforms, the duration, replacement rate and the tax rate effects, are studied in section 6.5, while labor market equilibria without benefits are evaluated in section 6.6. In section 6.7 the structural and institutional interactions that may act as unemployment amplifiers are discussed in view of the obtained results. A welfare analysis based on individual welfare in different structural and UI settings is presented in the eighth section. Finally, the results are related to more favorable unemployment trends after 1997. The conclusion evaluates the features embodied in the model economy with respect to the resulting model dynamics to derive lessons from the model design." The thesis ends by proposing guidelines for future improvements of the model and directions for further research