When is Containment Decidable for Probabilistic Automata?

The containment problem for quantitative automata is the natural quantitative generalisation of the classical language inclusion problem for Boolean automata. We study it for probabilistic automata, where it is known to be undecidable in general. We restrict our study to the class of probabilistic automata with bounded ambiguity. There, we show decidability (subject to Schanuel's conjecture) when one of the automata is assumed to be unambiguous while the other one is allowed to be finitely ambiguous. Furthermore, we show that this is close to the most general decidable fragment of this problem by proving that it is already undecidable if one of the automata is allowed to be linearly ambiguous

Optimizacija vremena zamjene vatrostalne obloge na segmentnim pećima

The goal of the study is to establish the influence of temporal wearing of refractory lining on energy losses of the furnaces by conducting heat through the furnaces walls. Object of the study were sectional furnaces, type SELAS, situated in the seam tubes production line in Željezara Sisak, Croatia. In order to reduce production costs, it was attempted to define the timely replacement of refractory lining by the criteria of comparing the costs resulted by heat loss through the furnace lining with the costs of refractory lining replacement. Data for the calculation of heat losses was obtained by use of the infrared camera.Rad je izrađen s ciljem da se utvrdi utjecaj vremenskog trošenja vatrostalne obloge na energetske gubitke provođenjem topline kroz ziđe peći. Kao objekt istraživanja odabrane su segmentne peći tipa SELAS, koje se nalaze u valjaonici šavnih cijevi Željezare Sisak. U cilju smanjenja proizvodnih troškova pokušala se odrediti pravovremena zamjena vatrostalne obloge pojedinog segmenta prema kriteriju usporedbe povećanih proizvodnih troškova, nastalih povećanjem energetskih gubitaka provođenjem topline kroz ziđe peći, s troškovima zamjene vatrostalne obloge. Za proračun gubitaka topline koristili su se podaci dobiveni snimanjem infracrvenom kamerom

Analiza procesa izgaranja u peći za taljenje aluminija

The composition of gaseous combustion product leaving the chamber of aluminium melting furnace in TLM Šibenik was investigated by measurements and numerical analysis in order to reduce the fuel consumption and increase the capacity of the existing furnace. Investigations were motivated by the fact that the actual specific fuel consumption was considerably higher and the actual furnace production was considerably lower than the design values according to the furnace technical documentation and the previous reached values in practice.Sastav plinovitih produkata izgaranja koji napuštaju radni prostor peći za taljenje aluminija u TLM Šibenik je istraživan mjerenjima i numeričkom analizom u cilju da se smanji potrošnja goriva i poveća kapacitet postojeće peći. Istraživanja su bila motivirana činjenicom da je stvarna specifična potrošnja goriva znatno veća, a kapacitet peći znatno manji od projektiranih vrijednosti prema tehničkoj dokumentaciji peći i prethodno u praksi postignutih vrijednosti

Termofizička svojstva serpentinita

In this article serpentinite from Banovina, Croatia, was studied. The antigorite is main mineral constituent of that rock. The dilatation curve shows that the first contraction of sample is coursed by dehydratation of antigorite at nearly 660°C. In spite of this, the second contraction of sample, which begines at nearly 860°C, is incident with olivine phase formation. The morphology of the serpentinite before and after thermal treatment was observed with the optical microscope. Image of serpentinite before thermal treatment is characterized by inclusions of olivine as primary mineral left as residue in process of serpentinization. Image of serpentinite after thermal treatment was changed by water disappear. The first thermal treated and than milled serpentinite has better properties than the first milled and than thermally treated serpentinite.U ovom radu istraživan je serpentinit s nalazišta na Banovini u Hrvatskoj. U toj mineralnoj sirovini prevladavajući mineral je antigorit. Dilatacijska krivulja ukazuje da je prva kontrakcija uzorka uzrokovana dehidratacijom antigorita na približno 660°C. Nasuprot tome, na drugu kontrakciju uzorka koja počinje pri približno 860°C utječe stvaranje olivina. Morfologija serpentinita prije i poslije termičke obradbe promatrana je optičkim mikroskopom. Izgled serpentinita prije termičke obradbe karakteriziran je uključcima olivina kao primarnog minerala zaostalog u procesu serpentinizacije. Izgled serpentinita poslije termičke obradbe promijenio se uslijed eliminacije vode. Prvo termički obrađen te potom mljeven serpentinit ima bolje karakteristike od prvo mljevenog, a potom termički obrađenog serpentinita

Utjecaj brzine hlađenja na svojstva kalibrirnog valjka od legiranog željeznog lijeva

Directional heat transfer was investigated by temperature measurements in the casting and in the mould using thermocouples. Measurements were performed in operating conditions during pouring, solidification, and cooling of the casting. Total measurement time was 35,5 hours. After cutting, specimens were extracted for metallographic and hardness testing. Test results provided confirmation of directional heat transfer (directional cooling) that would ensure acquirement of a desired casting structure and mechanical properties.Usmjereni prijenos topline u odljevku i kalupu praćen je mjerenjem temperature termoparovima tijekom ulijevanja taljevine u kalup, skrućivanja i hlađenja odljevka. Ukupno trajanje mjerenja iznosilo je 35,5 sati nakon čega je odljevak izrezan i uzeti su uzorci za metalografsku analizu i mjerenje tvrdoće. Rezultati ovih ispitivanja potvrdili su usmjereno odvođenje topline (usmjereno hlađenje) što osigurava dobivanje željene mikrostrukture i mehaničkih svojstava odljevka

Pokazatelji rada kružne peći u restriktivnim uvjetima proizvodnje

The heating operation of the rotating-hearth furnace involving semi-finished steel products was analysed, and specific heat consumption was determined as a function of furnace productivity. The aim was to find out how a change in productivity, which is not accompanied by a modification of the thermal regime, can affect the heating quality and surface oxidation of products.Analizirana je provedba zagrijavanja čeličnih poluproizvoda u kružnoj peći i određena je specifična potrošnja topline u ovisnosti o proizvodnosti peći. Istražen je utjecaj promjene proizvodnosti kružne peći pri nepromijenjenom toplinskom režimu na kvalitetu zagrijavanja čeličnih poluproizvoda i na oksidaciju njihove površine

Mogućnosti uspješnog poslovanja Valjaonice čeličnih cijevi u tržišnim uvjetima

Taking statistically-documentary basis as a starting point and applying adequate mathematical methods, numerical functional relations between total annual production and single production expenses, i.e. average total production expenses are defined. Functional relation between both of them with different number of employees compared to the average number of employees in the analysed period of time is also defined.Polazeći od statističko-dokumentacijske osnove i primjenom odgovarajuće matematičke metode određeni su numerički funkcionalni odnosi među ukupnom godišnjom proizvodnjom i pojedinačnim troškovima proizvodnje, odnosno prosječnim ukupnim troškovima proizvodnje. Također je određen funkcionalni odnos među jednim i drugim pri različitom broju zaposlenika u odnosu na prosječan broj zaposlenika u analiziranom razdoblju

Effect of glycerol content and pH value of film-forming solution on the functional properties of protein-based edible films

The work is concerned with the effects of glycerol content and pH value of film forming solution on the functional properties of protein-based films. The films were produced of chicken breast proteins, dissolved under either acidic (pH 3) or alkaline (pH 11) conditions, with different concentrations of glycerol (35%, 50% and 65% w/w of protein content). Glycerol content affected significantly mechanical properties, water vapor permeability, color at pH 3 and film solubility (p<0.05). The pH value had significant influence on light transmission, color, transparency and film solubility (p<0.05). Considering the results of mechanical properties and film solubility, the obtained films are in the acceptable range for the use as a packaging material. It was estimated that water vapor permeability, color, light transmission and transparency need to be improved for the application

Utjecaj brzine hlađenja na svojstva kalibrirnog valjka od legiranog željeznog lijeva

Directional heat transfer was investigated by temperature measurements in the casting and in the mould using thermocouples. Measurements were performed in operating conditions during pouring, solidification, and cooling of the casting. Total measurement time was 35,5 hours. After cutting, specimens were extracted for metallographic and hardness testing. Test results provided confirmation of directional heat transfer (directional cooling) that would ensure acquirement of a desired casting structure and mechanical properties.Usmjereni prijenos topline u odljevku i kalupu praćen je mjerenjem temperature termoparovima tijekom ulijevanja taljevine u kalup, skrućivanja i hlađenja odljevka. Ukupno trajanje mjerenja iznosilo je 35,5 sati nakon čega je odljevak izrezan i uzeti su uzorci za metalografsku analizu i mjerenje tvrdoće. Rezultati ovih ispitivanja potvrdili su usmjereno odvođenje topline (usmjereno hlađenje) što osigurava dobivanje željene mikrostrukture i mehaničkih svojstava odljevka

Analiza procesa izgaranja u peći za taljenje aluminija

The composition of gaseous combustion product leaving the chamber of aluminium melting furnace in TLM Šibenik was investigated by measurements and numerical analysis in order to reduce the fuel consumption and increase the capacity of the existing furnace. Investigations were motivated by the fact that the actual specific fuel consumption was considerably higher and the actual furnace production was considerably lower than the design values according to the furnace technical documentation and the previous reached values in practice.Sastav plinovitih produkata izgaranja koji napuštaju radni prostor peći za taljenje aluminija u TLM Šibenik je istraživan mjerenjima i numeričkom analizom u cilju da se smanji potrošnja goriva i poveća kapacitet postojeće peći. Istraživanja su bila motivirana činjenicom da je stvarna specifična potrošnja goriva znatno veća, a kapacitet peći znatno manji od projektiranih vrijednosti prema tehničkoj dokumentaciji peći i prethodno u praksi postignutih vrijednosti