RHEOLOGICAL PROPERTIES AND THE ENERGETIC VALUE OF WHEAT FLOUR SUBSTITUTED BY DIFFERENT SHARES OF WHITE AND BROWN RICE FLOUR

In order to produce dough with a lower gluten content, more enriched with rice components and satisfactory rheological properties, the rheological properties, energetic value and cake baking properties of wheat and white or brown rice flour in shares from 3 to 30% (w/w) were investigated in this paper. The water absorption in wheat-rice flour mixtures was lower and decreased to 53.5% and 54.0% along with the increase of the white and the brown rice flour share, respectively, than in wheat flour, where it was 58.8%. In the dough made from rice flour, a gluten network had thinner filaments, about 2 and 1 μm in width for white and brown rice flour, respectively, compared to those in the dough from wheat flour only, where it was about 7 μm. The dough from rice flour had almost twice higher gelatinization maximum than the gelatinization maximum of the wheat flour only. The energetic values of the dough from rice flour were smaller than the energetic value of the wheat flour, for only 1.32%. Based on Cluster analysis, the white or brown rice flour share of 20% was pointed out

Mechanical properties of welded pipes produced by high frequency welding of the steel API J55

Izbor čelika, dimenzija i načina proizvodnje zaštitnih zavarenih cevi je deo procesa konstruisanja, jer je u uskoj vezi sa funkcijom cevi kao konstrukcijske celine u određenim uslovima eksploatacije za predviđeni vek trajanja. Kvalitet zavarenih spojeva u procesu proizvodnje cevi definiše se karakteristikama koje one moraju posedovati da bi zadovoljile određene zahteve, što se postiže izborom odgovarajućih postupaka i parametara zavarivanja, sprovođenjem programa kontrole svih tehnoloških operacija u njihovoj izradi i mehaničkim i tehnološkim ispitivanjima otpornosti i deformacije osnovnog materijala i zavarenih spojeva cevi. U radu su prikazani rezultati ispitivanja mehaničkih osobina uzdužno zavarenih cevi, izrađenih visokofrekventnim kontaktnim zavarivanjem od čelika povećane čvrstoće API J55.Selection of the steel, dimensions and manufacturing methods for protective welded pipes is part of the design process, because it is closely related to the function of tube construction as a whole under certain conditions, for a calculated service life. The quality of welded joints in the process of tubes production is defined by characteristics that they must have to meet certain requirements, which are achieved by choosing appropriate procedures and welding parameters, by controlling all unit operations in their preparation and mechanical and engineering stress and strain tests and base material of welded joints. This paper presents the results of the mechanical properties of longitudinally welded pipes. Casing welded pipe intended for oil and gas wells are made by high frequency contact welding of steel API J55, with increased strength

Native Non-Saccharomyces Yeasts as a Tool to Produce Distinctive and Diverse Tamjanika Grape Wines

The enological potential of two previously characterized indigenous yeast isolates, Hanseniaspora uvarum S-2 and Candida famata WB-1, in pure and sequential inoculation with commercial yeast Saccharomyces cerevisiae QA23 were analyzed in industrial-scale vinification of the grape variety Tamjanika. Their contribution to the quality and aroma profile was investigated by quantifying volatile compounds and wine sensory evaluation. Both yeast isolates were able to complete alcoholic fermentation, to reduce ethanol concentration up to 1.06% v/v (in monoculture) in comparation to S. cerevisiae QA23, and to enhance aroma and sensory profile. Based on calculated odor activity values (OAV), p-cymene, ethyl hexanoate, ethyl octanoate, and ethyl decanoate were the major aroma volatile compounds in all Tamjanika wine samples. Analyzed yeast strains significantly affected relative contribution of volatile compounds and can be considered responsible for the differences and uniqueness of the obtained wine samples. Besides confirmation of good enological and fermentative characteristics, selected isolates can be characterized as high ester-producing strains with potential to enhance the floral and fruity aromas of wine. The present study represents a further step toward the use of indigenous yeast isolates at industrial-scale fermentation in order to ensure the regional signature of Tamjanika wine

Metodologija dizajniranja simulacijskih sustava temeljenih na metodi diskretnih događaja u proizvodnom ambijentu

The paper considers Discrete Event Simulation design methodology. Primary objective is proposal of comprehensive, scientifically established design methodology to structure, guide, and improve manufacturing processes modeling efforts. Proposed approach replicate structure and behavior of original system at desired level of abstraction, incorporates specific academic knowledge in simulation solution and results in object oriented application architecture completely consistent with production planning and scheduling ontology. The paper begins pointing out importance of modeling and equality between knowledge and models from viewpoint of modern cybernetic science and referenced cybernetics theory relocates in manufacturing systems and discrete event simulation domain. Paper then proceeds to discuss a structure and main steps of proposed methodology with a more detailed discussion of simulation based production planning and scheduling. Finally, an example of successfully designed simulation solution is given. Proposed approach gives verbal and mathematical problem description, builds ontology of problem domain, uses Extended Petri Nets, event graphs and activity cycle diagrams as modeling tools, in order to obtain faithful model which easily can be replicated in object oriented class and object hierarchy. Methodology highlights inevitability of knowledge transfer between business processes, software development and academic research experts. Integration and overlapping of mentioned fields of knowledge result in object oriented application architecture fully consistent with ontology derived from conceptual phase of design methodology. Proposed methodology enables convergence of comprehensive but static MIS knowledge in dynamic simulation model in order to fully utilize its prediction power for effective integration of strategic and tactical decision making.U radu se razmatra metodologija dizajniranja računalnih simulacijskih sustava temeljenih na metodi diskretnih događaja. Primarni cilj je prijedlog sveobuhvatne, znanstveno utemeljene metodologije dizajniranja koja formulira, usmjerava te poboljšava nastojanja modeliranja proizvodnih procesa. Predloženi pristup replicira strukturu i ponašanje originalnih sustava na željenoj razini apstrakcije, inkorporira specifična akademska znanja u simulacijski sustav te rezultira u objektno orijentiranoj arhitekturi aplikacije koja je u potpunosti konzistentna sa ontologijom planiranja i terminiranja proizvodnje. Rad započinje naglašavanjem značaja modeliranja stavljajući znak jednakosti između znanja i modela iz perspektive moderne kibernetičke znanosti te pomenutu kibernetičku teoriju relocira u domene proizvodnih sustava i simulacije diskretnih događaja. U radu se potom daju osnovni podaci o strukturi i glavnim koracima predložene metodologije uz detaljnije objašnjenje planiranja i terminiranja proizvodnje uz pomoć simulacije. Na kraju se opisuje primjer uspješno dizajniranog simulacijskog sustava. Predloženi pristup daje verbalni i matematički opis problema, gradi ontologiju domene problema, koristi proširene Petrijeve mreže, graf događaje i cikluse dijagrama aktivnosti kao alate modeliranja, sa svrhom dobijanja vjernog modela koji se lako može replicirati u objektno orijentiranu hijerarhiju klasa i objekata. Metodologija ističe neizbježnost transfera znanja između stručnjaka za poslovne procese, te eksperata iz oblasti razvoja softvera i akademskih istraživanja. Integracija i preklapanje navedenih polja znanja rezultuje u objektno orijentiranoj arhitekturi aplikacije koja je potpuno u skladu s ontologijom koja slijedi iz konceptualne faze metodologije dizajniranja. Predložena metodologija omogućava konvergenciju sveobuhvatnog ali statičkog znanja sadržanog u informacijskom sustavu upravljanja u dinamički simulacijski model, sa ciljem potpunijeg iskorišćenja mogućnosti predviđanja te učinkovito integriranje strateškog i taktičkog odlučivanja

Microbial fertilizers: A comprehensive review of current findings and future perspectives

Plant growth promoting microorganisms (PGPM) are an important group of microbial inoculants, which exist in rhizosphere and have the ability to inhabit the root of the plants and improve their development. Their positive influence is achieved through solubilization of phosphorus, nitrogen fixation, production of plant nutrients and phytohormones, protection from pathogens and recovery from stressful environmental conditions. This is the main reason for the increasing usage of many PGPMs which formulations are commonly known as microbial fertilizers. Microbial fertilizers represent an attractive replacement for chemical fertilizers that are polluting the environment. They are used to increase the crop yield in an eco-friendly way while relying on sustainable agriculture principles. The biggest problem nowadays is the very poor quality of such products, which results in the lack of confidence and makes commercialization much more difficult. In order to increase production and hence the commercialization of microbial fertilizers, desired quality and stability should be achieved. For this reason, many researches are done in this particular field. In order to develop an optimal product, it is important to know and understand the process, including the physiology of bacteria and plants, mass multiplication technological processes as well as the existing formulation and the specific effect on the desired plant. For this purpose, the aim of this review is to indicate the significance of microbial fertilizers and their beneficial effects on the plants, as well as to give a brief survey of the different aspects of production processes with a special emphasis on mass multiplication

Comparison of antioxidant and antimicrobial activities of extracts obtained from Salvia glutinosa L. and Salvia officinalis L.

Antioxidant and antimicrobial activities as well as total phenols and flavonoids contents of Salvia glutinosa L. (glutinous sage) and Salvia officinalis L. (sage) extracts were studied. Methanol and aqueous ethanol (70% v/v) were used for extraction of bioactive compounds, both in the presence and the absence of ultrasound, from herb and the spent plant material remaining after the essential oil hydrodistillation. The ratio of plant material to extracting solvent was 1:10 g/ml. Antioxidant and antimicrobial activities of the extracts were found to depend on the type of plant material and the extraction conditions. The plant materials from which essential oil had been recovered were proven to be valuable raw materials for making various herbal preparations

The application of natural organic compounds in bakery industry

Investigations include the analysis of the impact of commercial products: complex additive (0.1, 0.3, and 0.5%), L-ascorbic acid (0.002, 0.004 and 0.012%), diacetyl ester of tartaric acid with monoglycerides (DATEM E472e, 0.1, 0.3, and 0.5%), α-amylase (0.002, 0.006 and 0.012%), xylanase (0.004, 0.012 and 0.024%), alcohol extract of rosemary, thyme or sage (0.5, 1.0 and 2.0%), as well as the combination of complex additive and rosemary, thyme and sage extract on rheological characteristics of dough. The study includes amylograph, farinograph and extensograph analysis of dough with and without additives (control sample). The volume of lost CO2 gas (mL) is the lowest in dough samples with an added combination of complex additive and thyme extract (0.05 and 0.5%) and rosemary extract (2.0%). In the samples with thyme extract (1.0%) added, the volume of lost gas is at a level of samples with added complex additive, DATEM, and L-ascorbic acid

Structural life assessment of oil rig pipes made of API J55 steel by high frequency welding

Predmet rada je analiza integriteta i procjena preostalog vijeka zaštitnih zavarenih cijevi izrađenih od čelika API J55 visokofrekventnim kontaktnim zavarivanjem (VF). Eksperimentalna ispitivanja mehaničkih svojstava osnovnog materijala i ispitivanja na zamor izvršena su na cijevima povučenim iz naftne bušotine nakon 70 000 sati rada. Ispitivanje brzine rasta zamorne pukotine da/dN i opsega faktora intenzivnosti naprezanja na pragu zamora, ∆Kth, izvedeno je na standardnim Charpy epruvetama sa zarezom. Broj ciklusa do loma je izračunat na osnovi početne i krajnje kritične duljine pukotine. Na osnovi broja ciklusa do loma i broja ciklusa opterećenja određen je preostali vijek cijevi s vanjskom aksijalnom površinskom pukotinom. Pokazano je da je preostali vijek osjetljiviji na promjenu opsega opterećenja nego na početnu dubinu pukotine.Structural life of welded pipes made of API J55 steel by high-frequency (HF) welding has been evaluated. Experimental tests of base metal mechanical properties, including fatigue properties, were conducted on pipes after 70 000 hours of service in an oil drilling rig. The fatigue crack growth rate and fatigue threshold is obtained using the pre-cracked Charpy specimens. The number of cycles to the final fracture is then calculated using initial and critical crack depths. Based on the number of cycles to the final fracture and the remaining fatigue lifetime of pipes with axial outer surface crack are determined. It was shown that the remaining fatigue lifetime is more sensitive to the changes in the stress range than to the initial crack depth

Ispitivanje prisustva antitela protiv goveđeg herpesvirusa-1 u krvnom serumu teladi pre ishrane kolostrumom

The paper presents the results of investigations of the presence of the bovine herpesvirus-1 (BHV-1) in samples of blood serum from 106 cows and 107 of their calves (one cow had twins). Blood was sampled from the cows immediately after parturition, and from the calves before feeding on colostrum. The examined cows and their calves originated from 5 herds in which previous investigations had shown infection with the bovine herpesvirus-1. The determination of antibodies against BHV-1 was performed using the method of virus neutralization in culture of MDBK cells with 100 TCID/50 viruses (BHV-1, TN-41 Am. Bio Research, USA). Antibodies against BHV-1 were determined in all blood serum samples of cows and in 16 samples of precolostral blood serums of calves. The antibody titer values in cows ranged from 1:4 to 1:512, and in calves the determined values were from 1:2 to 1:16. The results indicate that cows that are seropositive to BHV-1 can deliver calves seropositive to BHV-1 in about 15% cases. This must be kept in mind in selecting cows for the production of breeding material, in particular bulls for reproduction centers, as well as in making a programme for the immunoprophylaxis of calves against BHV-1. .U radu su prikazani rezultati ispitivanja prisustva antitela protiv goveđeg herpesvirusa-1 (BHV-1) u uzorcima krvnih seruma 106 krava i 107 njihove teladi (jedna krava je otelila blizance). Uzorkovanje krvi od krava je vršeno odmah nakon partusa, a od teladi pre ishrane kolostrumom. Ispitivane krave i njihova telad poticali su iz 5 zapata u kojima je ranijim ispitivanjima utvrđena infekcija goveđim herpesvirusom-1. Utvrđivanje antitela protiv BHV-1 vršeno je metodom virus neutralizacije na kulturi MDBK ćelija sa 100 TCID/50 virusa (BHV-1, TN-41 Am. Bio Research, USA). Antitela protiv BHV-1 utvrđena su u svim uzorcima krvnih seruma krava i u 16 uzoraka prekolostralnih krvnih seruma teladi. Vrednosti titra antitela iznosile su kod krava od 1:4 do 1:512, a kod teladi od 1:2 do 1:16. Rezultati ukazuju na to da krave koje su seropozitivne na BHV-1 mogu da otele telad seropozitivnu na BHV-1 u oko 15% slučajeva. Ovo se mora imati u vidu kada se vrši izbor krava za proizvodnju priplodnog materijala, a posebno bikova za reprocentre, kao i kada se pravi program imunoprofilakse teladi protiv BHV-1.