Oblikovanje robotske stanice za rezanje čeličnih profila

U sklopu diplomskog rada potrebno je projektirati robotsku stanicu za rezanje profila. Sama inicijativa za takvim diplomskim radom potekla je od strane brodogradilišta Uljanik d.d., stoga će se i robotska stanica projektirati na način da zadovoljava potrebe brodogradnje. Pod projektiranje robotske stanice podrazumijeva se izrada detaljnog odabira i rasporeda svih potrebnih uređaja u prostoru, te u konačnici i idejno povezivanje svih uređaja u jednu cijelinu, kako bi se primjenom nekih od upravljačkih mogućnosti, pomoću industrijskih računala ili kontrolera, dobio i funkcionalan rad takve stanice. Oblikovanje sustava bit će u cijelosti izveden na računalu, odnosno prostorni raspored uređaja bit će ugrađen u CAD programskom paketu za 3D modeliranje (CATIA) sa detaljnim opisom pojedinih elemenata sustava, dok će se upravljački dio vezan za diplomski rad izvesti u sklopu jednog programa za simuliranje robotiziranih proizvodnih sustava. Simulacija će se izvoditi u programu ROBOGUIDE, japanskog proizvođača robota FANUC. Ono što omogućuje ovaj program jest: stavaranje radne okoline uređaja i strojeva (u ovom slučaju robotske ruke), programiranje robotskih kontrolera, mogućnost off-line simulacije sustava (bez da su elementi sustava spojeni na računalo), lakša provjera i promjena korištenih elemenata sustava. Pomoću navedenih programskih paketa bit će virtualno oblikovana robotska stanica za rezanje profila. Unatoč tome što se jedna takva stanica već nalazi u sklopu poduzeća naglasak ovog diplomskog rada bit će upravo na tome da se dobiveni simulacijski rezultati iskoriste u usporedbi s postojećim sustavom kako bi se ukazali mogući nedostaci postojeće stanice ili eventualna ekonomska iskoristivost jedne takve robotske stanice. Dakako će se pri tome pokušat primjenjivati što naprednije tehnologije kako bi se dobili što bolji rezultati, te na taj način usporediti i trenutačnu učinkovitost postojeće stanice

Changes in nutrition type between generations influence on bone structural changes in rat female offspring

Background and Purpose: It is believed that changes in feeding protocol between generations have influence on the balance of the whole organism. Epidemiological studies suggest that skeletal growth is programmed during intrauterine and early postnatal life. The aim of the study was to determinate impact of maternal dietary fat excess and nutrition of female offspring on the bone structural changes in latter. Materials and Methods: Ten female Sprague Dawley rats were randomly divided in two groups. One group was fed with high content of saturated fatty acid food (HFD) and the other with standard laboratory chow (CD). Offspring from both groups were randomly divided in two subgroups after coupling and lactation period, subsequently there were four groups of offspring (n=6 each) with different feeding protocol: a) CD-CD – control diet mothers and offspring, b) CD-HFD – control diet mothers and high fat diet offspring, c) HFD-CD – high fat diet mothers and control diet offspring and d) HFD-HFD – high fat diet mothers and offspring. At the age of 18 weeks in female offspring bone microstructure was analyzed in fifth lumbar vertebra using digital photographic images. Results and Conclusions: The control diet female offspring of high fat fed mothers showed the highest values of trabecular thickness and trabecular number, while the CD-HFD offspring group had the highest values of trabecular separation and cortical thickness. Maternal nutritional status affects the future development of offspring

Osseous tools and personal ornaments from the Epigravettian sequence at Badanj

The Late Upper Palaeolithic (Epigravettian) sequence at Badanj has yielded an important dataset about the occupation of the hinterland of the Eastern Adriatic catchment zone in the late Pleniglacial. The site also harbors one of the rare occurrences of Upper Palaeolithic parietal “art” in southeastern Europe in the form of a large rock engraving. Another notable aspect of the site is the presence of engravings on portable objects made from bone. The first excavations at Badanj, conducted in 1976–1979 in the zone around the engraved rock, yielded a surprisingly large number of personal ornaments (over 1000 specimens) from a variety of primarily marine gastropods, scaphopods, and bivalves, and red deer canines. Here we review what is currently known about the site and report our preliminary findings from the study of the collection of personal ornaments as well as osseous tools, some of which were marked by regular incisions forming decorative motifs. We also report two new direct accelerator mass spectrometry (AMS) dates on antler barbed points

Towards a Harmonized Accelerated Stress Test Protocol for Fuel Starvation Induced Cell Reversal Events in PEM Fuel Cells: The Effect of Pulse Duration

Global fuel starvation is an undesired event during fuel cell operation that results in serious degradations at the anode catalyst layer caused by the concomitant reversal of the cell potentials. Several groups have therefore intensified their research efforts towards the implementation of suitable diagnostic tools and accelerated stress test (AST) protocols that mimic cell reversal events. However, the current number of different test protocols requires consolidation and harmonization to define durability targets towards cell reversal tolerance and to benchmark newly developed materials. To create a basis for harmonization, this study examines the difference between pulsed and quasi-continuous AST protocols at the catalyst-coated membrane level. Utilizing a single-cell setup combined with an on-line mass spectrometer, a 2.5-fold increase in the carbon corrosion rates were found for short-pulsed compared to long-lasting cell reversal events. The enhanced corrosion was associated with a 2.2-fold higher loss of electrochemically active surface area and a 15% higher reduction in anode catalyst layer thickness. By contrast, the overall cell performance decreased additionally by 40–50 mV for samples under long-lasting cell reversal events. The decay is mainly driven by an increased ohmic resistance, presumably originating from a more pronounced surface oxide formation on the carbon support

The Oral Status of Adult Population in the Croatian Town of Knin: a Cross Sectional Study

Svrha: Epidemiološka istraživanja u mnogim zemljama pokazuju neravnomjernu raspodjelu oralnih bolesti u populaciji – primarno karijesa, te je zato glavna svrha ovoga presječnog istraživanja bila dobiti relevantne podatke oralnog statusa populacije u Kninu i okolici određene prema smjernicama SZO-a. Ispitanici i metode: U istraživanje je bilo uključeno 414 ispitanika u dobi od 18 do 65 godina. Zabilježeni podatci uključivali su opću anamnezu, ekstraoralni status, status oralne sluznice, status temporpomandibularnih zglobova, zubni, parodontni i protetski status, te jesu li potrebni restaurativni zahvati. Obavljena je i usporedba među različitim grupama, ovisno o dobi, spolu, stupnju obrazovanja i podrijetlu. Rezultati: Prosječno je KEP indeks bio 17,3, zatim 1,7 – karijes, 6,2 – ispuni i 9,4 – ekstrahirani zubi. SIC indeks iznosio je 26,4. Razlika je bila značajna u grupama prema dobi i stupnju obrazovanja (p < 0,001). Postotak osoba s najvišim zbrojem CPI-a od 0 do 4 bio je 27,3, 16,9, 36,5, 16,4, i 2, 2,9 posto. Razlika između dobnih grupa u CPI vrijednostima bila je statistički značajna, a razlika ovisno o spolu i podrijetlu nije bila značajna (p = 0,001). Zaključak: Populacija u Kninu i okolici ima vrlo loš oralni status, najvjerojatnije zbog posljedica rata 1990-ih godina i ekonomske tranzicije te zato što nema nacionalnog programa za promicanje oralnoga zdravlja.The aim: Epidemiologic studies in many countries show uneven distribution of oral diseases (primarily caries) within the population. This is why more studies are oriented towards specific regions or subpopulations instead of large scale national surveys. The major purpose of this cross sectional study was to obtain relevant data about the oral status of the population of Knin and its surroundings according to the WHO criteria. Subjects and methods: The study included 414 participants aged between 18 and 65. The recorded variables included general anamnestic data, extraoral status, oral mucosa status, temporomandibular joint status, dental, periodontal and prosthetic status, and the need for dental restoration. The comparison between different groups regarding age, gender, educational level and origin was made. Results: DMFT index was 17.3 – with on average 1.7 caries, 6.2 fillings, and 9.4 teeth extracted. SiC index equaled 26.4. The difference was significant regarding the level of education and age (p<0.001). The percentages of individuals with the highest CPI scores from 0-4 were 27.3, 16.9, 36.5, 16.4 and 2.9%, respectively. The difference between the age groups in CPI scores was statistically significant, while the differences according to the gender and origin were not significant (p=0.001). Conclusion: The population of Knin and the surrounding area exhibited very bad oral status which can be attributed to the consequences of the war in the 1990-ies, the economic transition, and the lack of national program for oral health promotion