168 research outputs found
FEA modeling of orthogonal cutting of steel: a review
Orthogonal cutting is probably the most studied machining operation for metals. Its simulation with the Finite Element Analysis (FEA) method is of paramount academic interest. 2D models, and to a lesser extent 3D models, have been developed to predict cutting forces, chip formation, heat generation and temperature fields, residual stress distribution and tool wear. This paper first presents a brief review of scientific literature with focus on FEA modelling of the orthogonal cutting process for steels. Following, emphasis is put on the building blocks of the simulation model, such as the formulation of the mechanical problem, the material constitutive model, the friction models and damage laws
Biological and taxonomical investigations of some oak species
Hermaphroditic flowers blooming unseasonably on an oak tree (»the green oak«) of uncertain hybrid origin prompted a detailed investigation into the biology of the flowering, and the morphology of various traits of the tree, which is growing in an urban area near
Zadar, northern Dalmatia, Croatia. Hermaphroditic flowers were also detected on one holm oak tree from Weihenstephan, Germany. Since the first oak tree was described as a hybrid between Q. cerris f. austriaca Q. ilex, scanning electron microscope investigations
of pollen and hairs on the leaves of three species were made, on: Q. ilex L., Q. cerris L. and the »green oak«. Oak pollen is of elliptical shape and tricolpate. The ornamentation of the pollen grains of Q. cerris and the »green oak« were similar concerning the ornamentation of the exine – warty and rough and with small rounded protrusions – as well as the size of the pollen grain. Q. ilex pollen was much smaller and the surface lacked the small irregularly shaped protrusions typical of the other oaks.Within samples of holm oak
pollen, significant difference in the surface structures was observed. Concerning the different types and number of hairs on the leaf surfaces, Q. ilex revealed a much greater number of stellate hairs on the upper leaf side as compared to Q. cerris and the »green oak«. Simple uniseriate hairs and simple unicellular hairs were missing on the leaves of Q. ilex, but were present on both the other oaks. To sum up the results, the »green oak« and Q. cerris reveal some similarities whereas Q. ilex does not
ECONOMIC AND SOCIAL RESPONSIBILITY OF FINANCIAL AUDIT - IN NEW DIMENSION
We think that financial institutions have a greater social responsibility to develop theircustomers’ financial culture than to support a football team. We assert that nowadaysfinancial institutions have a responsibility to be able to continue to operate banks withoutauxiliary state support. We believe that auditors, who for decades certified the financialreports of banks whose balance sheets were fictitious and whose depositors’ andshareholders' money was not safe, played no small role in the development of the recentfinancial crisis. Consequently we hold that the auditors’ greater social responsibility isunavoidable. On the other hand, after the crisis, due to the fact that social responsibility hascome to the fore, auditors also have to prepare for the challenge that corporate reports areincreasingly integrated reports which, in addition to mandatory economic information, alsovoluntarily impart data on social and environmental impact and activities
Pollen traits of some American ashes investigated by a scanning electron microscope
Over last 130 years the American assh was often used for afforestation of Croatian lowland areas where the native narrow leafed ash (Fraxinus angustifolia Vahl) did not grow well. Due to unequivocal species identification of the American ash F. americana L. or F. pennsylvanica Marshall, pollen samples of concerned specimens were collected. Based on species pollen samples of F. americana and F. pennsylvanica, collected from trees growing at the Royal Botanical Gardens Hamilton in Canada, and on their distinctive morphological features, pollen samples of American ash trees from a plantation Črnovščak in Dugo Selo near Zagreb and from arboricultures in Zagreb were determined as Fraxinus pennsylvanica
NOVA METODA BORBE PROTIV EPIDEMIJE KOLERE U REDOVIMA RUMUNJSKE VOJSKE TIJEKOM BALKANSKOG RATA 1913
The history of cholera, a specific infection caused by Vibrio Cholerae, starts in ancient times.
The sixth pandemic that began in 1899 and lasted until 1923, started in India and came to Eastern Europe through Russia. The expansion of the epidemic in the Balkans was facilitated both by the 2 Balkan Wars and the First World War.
Romania, as a participant in these wars was affected by cholera, which was especially common among the army during the Balkan War. If the original source of the cholera issue is still controversial, both Romanians and Bulgarians accusing each other of being the basis of
the outbreaks south of the Danube, it is widely recognized that the extent of the disease was facilitated by the sanitary conditions of food preparation and drinking water sources among both Romanian soldiers and in the civilian population.
Under these conditions, in addition to numerous measures against cholera taken by the Ministry of War, Prof. I. Cantacuzino successfully experiments outbreak vaccination for the first time in the world with a vaccine prepared by himself and his collaborators.
The vaccine containing 25 breeds of vibriones was a success in terms of rapid development of a preparation, the application of which was achieved through a quick campaign and proved extremely efficient, imposing the Romanian method as an effective way to combat a disease
in full outbreak.Povijest kolere, bolesti uzrokovane bakterijom Vibrio Cholerae, seže do antičkih vremena.
Šesta pandemija kolere (1899-1923) započelaje u Indiji te je dosegla Istočnu Europu preko Rusije. Rasapu epidemije na balkanskom području pogodovala su dva balkanska rata i Prvi svjetski rat.
Rumunjska, kao jedan od sudionika ratova, bila je zahvaćena kolerom, koja je pogodila prvenstveno redove rumunjske vojske u vrijeme balkanskog rata. Iako je pitanje izvora bolesti još dan danas kontroverzno, pri čemu se Rumunji i Bugari međusobno optužuju da su uzrokom izbijanja epidemije južno od Dunava, jasno je da su rasapu bolesti doprinijeli sanitarni uvjeti pripreme hrane i izvori pitke vode kojima su se koristili kako rumunjski vojnici tako i
civilno stanovništvo.
U tim je uvjetima, uz brojne mjere zaštite protiv kolere pokrenute od strane Ministarstva rata, prof. I. Cantacuzino po prvi puta u svijetu uspješno testirao cijepljenje cjepivom kojeg je pripremio zajedno sa svojim suradnicima. Cjepivo je sadržavalo 25 vrsta vibriona i pokazao se uspješnim kako u brzini pripreme tako i u širokoj primjeni, čiju je uspješnost potpomogla brza zdravstvena kampanja. Cjepivo je pokazalo iznimnu učinkovitost, namečući rumunjsku metodu kao efikasni način borbe protiv bolesti u punom jeku epidemije
KRIZNI MENADŽMENT U SPORTU ZA VRIJEME PANDEMIJE COVID-19
Svjetski „lockdown“ uzrokovao je globalno zatvaranje cijelog gospodarstva. S posljedicama se suočavaju svi: od trgovina, uslužnih objekata, turističko-ugostiteljskih objekata, prijevoza pa sve do sporta kako profesionalnog, tako i rekreativnog. Krizni menadžment, kao novo područje menadžmenta bavi se predviđanjem događaja i definiranjem mogućih optimalnih odgovora na krizu te se odnosi na aktivnosti koje su usmjerene na ovladavanje situacija opasne po opstanak poduzeća. Osnova kriznog menadžmenta je korištenje mjera i metoda kako bi se kriza predvidjela i u ranoj fazi zaustavio njezin razvoj, no pandemiju je cijeli svijet dočekao nespreman. Posljedice su prvenstveno vidljive na ekonomskoj razini, ali i na društvenom i socijalnom aspektu života ljudi: od svjetskog zdravlja, obrazovnog sustava, financijskih institucija pa sve do sportske industrije. U radu se istražuju izazovi i posljedice koje su sportska događanja i sport općenito pretrpjeli u doba pandemije COVID-19
TREATMENT OF FISTULIZING CROHN’S DISEASE
Liječenje fistulirajućeg oblika Crohnove bolesti zahtijeva tijesnu suradnju gastroenterologa i kirurga te se temelji na striktnom individualnom pristupu koji uvijek uključuje adekvatnu nutricijsku potporu. Danas još uvijek ne postoje kontrolirane randomizirane studije koje bi adekvatno evaluirale učinkovitostt medikamentne kao niti biološke terapije u liječenju neperianalne fistulirajuće Crohnove bolesti. Retroperitonealne fistule sa slijepim završetkom kao i enterovezikalne fistule apsolutna su indikacija za kiruršku intervenciju. Kirurška intervencija je neophodna i u slučaju gastrokoličnih i duodenokoličnih fistula. U većini slučajeva simptomatske enterovaginalne fistule zahtijevaju kirurški tretman. Imunosupresivna terapija (azatioprin ili merkaptopurin) uz antibiotsku terapiju (ciprofloksacin + metronidazol) u kombinaciji s drenažnim kirurškim postupcima danas je prva medikamentna linija terapije kompleksne perianalne Crohnove bolesti. Svakako treba naglasiti potrebu za dugotrajnom terapijom održavanja kliničke remisije koja u selekcioniranih bolesnika uključuje postavljanje setona uz imunosupresivnu terapiju u razdoblju od najmanje godinu dana. Sukladno dostupnim studijama, anti TNF-terapija (infliksimab ili adalimumab) danas je druga medikamentna terapijska linija u liječenju kompleksnog perianalnog oblika Crohnove bolesti.The treatment of fistulating Crohn’s disease should include a combined medical and surgical approach and should be defined on an individual basis. Asymptomatic enteroenteric fistulas usually require no treatment, but internal fistulas (gastrocolic, duodenocolic, enterovesical) that cause severe or persistent symptoms require surgical intervention. While low asymptomatic analintroital fistula may not need surgical treatment, in case of a symptomatic enterovaginal fistula surgery is usually required. There are no controlled-randomized trials to assess the effect of medical treatment for non-perianal fistulating Crohn’s disease. The incidence of perianal fistulae varies according to the location of the disease, with its occurrence varying between 21-23%. The diagnostic approach should include an examination under anesthesia, endoscopy, and either MRI or EUS before the treatment begins. Asymptomatic simple perianal fistulas require no treatment. The presence of a perianal abscess should be ascertained and if present should be drained urgently. In case of a complex perianal disease, seton placement should also be recommended. Antibiotics (metronidazole and ciprofloxacine) are useful for treating complex perianal disease, however, when discontinued, most of the fistulas relapse. The current consensus suggests that azathioprine/6-mercaptopurine is the first line medical therapy for complex perianal disease, which is always given in combination with surgical therapy (seton, fistulotomy/fistulectomy). Anti TNF-αagents (infliximab and adalimumab) should be used as a second choice medical treatment. In refractory and extensive complex perianal disease a diverting stoma or proctectomy should be performed
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