26 research outputs found
The dominant effect of temperature on the fatigue behaviour of polymer gears
No full textThe testing procedures and reported tribological performance of polymer gears, which are seeing ever-increasing use by industry, still lack consistency and detail. One of the key parameters that affect a polymer\u27s mechanical properties, interface contact conditions and, consequently, the wear and fatigue behaviour, is the temperature. Temperature is well known to have a critical influence on all polymers, much more so than on metals or other materials. However, the temperatures - even for the same load and velocity - vary greatly with testing devices, gear sizes and shapes, surrounding environment, as do the cooling and heating rates. Moreover, the temperature, either root, flank or bulk, also varies with the operating conditions, meaning that even in the same S-N curve data at different stresses we actually obtain different temperatures. This suggests that the results from different tests and even different load levels, which are not temperature controlled, cannot be directly compared due to the important influence of the temperature on the polymers. This work presents the results of POM gears tested against steel gears under well-controlled temperature conditions, providing various S-N curves obtained at 30 °C, 50 °C and 70 °C that were kept constant at the gear root for three torque values (1.0 N m, 1.2 N m and 1.4 N m), and these are compared to data obtained under conditions that are typically considered to be "room temperature", which is in fact an uncontrolled temperature. The results confirm the important effect of the temperature on the fatigue life of POM gears, i.e., when kept at low temperature (30 °C), the fatigue life of POM gears is greatly improved
Tribological properties of polyamide (PA6) in self-mated contacts and against steel as a stationary and moving body
No full textThe time for which each contacting body is exposed to a tribological contact affects its interface temperature, third-body and tribofilm formation, and, as a result, the overall tribological behaviour, which may be particularly relevant with very dissimilar material pairs. This work focuses on the tribological properties of unreinforced polyamide (PA6) in self-mated contacts or against steel (SS) as a stationary (SS/PA6) or a moving contact (PA6/SS) body under dry-sliding conditions. Moreover, the effects of the contact pressure and the sliding velocity were investigated for these contacts. In addition, the contact conditions were carefully controlled with measurements of the specimen\u27s surface temperature using an infrared camera. The results show that the tribological behaviour indeed depends significantly on the contact configuration. The tribological properties of the stationary steel pin sliding against a rotating polymer disc (SS/PA6), as well as of a self-mated PA6/PA6 contact, depended substantially on the contact conditions used. In contrast, the contact configuration of a stationary PA6 pin sliding against a rotating steel disc (PA6/SS) showed only a negligible effect on changes in the sliding speed and the load. Moreover, this was clearly the best-performing contact in the study and the beneficial effect is explained by the ability of a rotating disc to remove the heat from the contact zone and, consequently, to lower the temperatures generated in the tribological contact
Analysis of growth in the case of company in the wholesale and retail trade
No full textDiplomski projekt obsega analizo rasti podjetja na primeru slovenskega podjetja Tehnoles d.o.o. Gre za podjetje, ki se ukvarja z suhomontažno gradnjo ter prodajo barv ter gradbenega materiala. Svoje proizvodne in storitve ponujajo tako domačim kot tudi tujim uporabnikom.
V teoretičnem delu diplomskega projekta smo opredelili pojem kaj je rast podjetja, zakaj naj bi podjetje rastlo, kakšni so vzroki za rast podjetja. Osredotočili smo se tudi podbrobneje na oblike rasti podjetja in značilnosti teh oblik rasti.
V aplikativnem delu diplomskega projekta sem izvedla analizo rasti podjetja od leta 2014- 2016 za 5 kazalnikov: sredstva, število zaposlenih za 3 leta, dodana vrednost na zaposlenega, čisti poslovni izzid za 3 leta ter čiste prihodke od prodaje. Na podlagi teh kazalnikov sem ugotovila, da je podjetje rastlo po številu zaposlenih, kar je vidno tudi po indeksu povprečne rasti podjetja, ki je najvišji od vseh. Pri ostalih kazalnikih pa se je pokazalo sorazmerno nihanje.In the thesis the author presents an analysis of a company\u27s growth on the example of the Slovenian company Tehnoles d.o.o. Tehnoles is a company that deals with dry construction and sale of paints and construction material. They offer their products and services to both, domestic and foreign customers.
In the theoretical part of the thesis, the author defined what there is to understand about the term company growth and what it embraces, why a company should grow, what the reasons for the growth of a company are. The author also focused on the forms of company growth and the characteristics of these forms.
In the applicable part of the thesis, the author carried out an analysis of the company\u27s growth from 2014 to 2016 based on five indicators: assets, number of employees for 3 years, added value per employee, net profit for 3 years and net sales revenue. On the basis of these indicators, the author came to the conclusion that the company grew according to the number of employees and also to the average growth index of the company, which was the highest of all indicators. However, the other indicators showed a proportionate fluctuation
Smrt in posmrtje v trilogiji Gartha Nixa Staro kraljestvo na ozadju grštva, judovstva in krščanstva
No full textDiplomsko delo obravnava smrt, dušo in posmrtje v trilogiji avstralskega pisatelja Gartha Nixa Staro kraljestvo, in sicer v primerjavi s starogrškim, judovskim in katoliškim pogledom na to temo. V prvem delu so na kratko predstavljeni življenje in delo avtorja ter njegova trilogija, ki je osrednji predmet obravnave, drugi del naloge pa je posvečen predstavam pekla, nebes, vic, limba, duše in posmrtnega življenja tako v trilogiji kot v omenjenih treh verstvih.The bachelor\u27s thesis discusses soul, death and the afterworld in The Old Kingdom trilogy by the Australian author Garth Nix in comparison to old Greek, Jewish and Christian views on the topics. In the first part of the work, the author\u27s life and work are briefly discussed, and the trilogy on which this thesis focuses is introduced. The second part focuses on themes of hell, heaven, purgatory, limbo, soul and after life in the trilogy and in comparison to the three belief systems mentioned
Mačke in literatura od 19. stoletja naprej
No full textOsrednja ideja pričujoče diplomske naloge je raziskovanje vpliva mačk na določene književnike na področju svetovne književnosti. V prvem delu na splošno in kratko predstavim vključenost mačk v človeško kulturo, izpostavim dela, v katerih je mačke možno zaslediti ali pa navedem avtorje, ki so bili znani ljubitelji mačk. V nadaljevanju sledi oris štirih izbranih del različnih piscev, ki prihajajo iz različnih časovnih obdobij. Izbrani avtorji si sledijo po časovnem sosledju, začenši z najstarejšim, ki prihaja iz obdobja romantike - E. T. A. Hoffmannom, nato sledi avtorica iz preloma 19. v 20. stoletje - gre namreč za Colette in nazadnje sodobnika Charles Bukowski ter Doris Lessing. Vsak segment je sestavljen iz kratke predstavitve avtorja samega, po potrebi pospremljen s predstavitvijo obdobja, v katerem je ustvarjal. Nato sledi predstavitev izbranega dela in podrobnejša analiza, pri kateri sem se zanesla tako na lastno interpretacijo kot tudi na že objavljene raziskave. Zaključek strni ugotovitve in poskuša najti skupne točke predstavljenim delom.This thesis\u27 main idea is to discover the influence of cats on certain writers of world literature. The first part briefly and generally presents the inclusion of cats in human cultureeither the literary works where this can be observed or the authors which shared an affection towards cats. The following part centres around four works by different writers who are all representatives of different literary periodsstarting with E. T. A. Hoffmann from Romanticism, continuing with a female author from the 19th and the 20th centuries - Collette and finishing with two modern writers Charles Bukowski and Doris Lessing. Each part consists of a brief presentation of the author and, if needed, also of a presentation of the period he or she belongs to. Then follows a presentation of the chosen work and a more detailed analysis based on additional literature or personal interpretation. The conclusion sums up the findings of the thesis and tries to find a common ground of the presented literary works
