Alkalni bipolarni elektrolizator

Uslijed stalnog povećanja cijena goriva, koje je potaknuto smanjenjem naftnih rezervi, smanjenjem proizvodnje i opskrbe gorivom, strahom od globalnog zatopljenja i promjene klime uslijed izgaranja fosilnih goriva, vodik je u posljednjih nekoliko godina postao vrlo zanimljiv. Zahvaljujući svojim mnogobrojnim prednostima vodik odnosno "gospodarstvo zasnovano na vodiku" bi u budućnosti moglo postati jedno od rješenja u ostvarivanju energetske održivosti. Ovaj diplomski rad prikazuje dobivanje elementarno čistog vodika elektrolizom vode . U radu je dan detaljan pregled elektrolize s kemijskog i termodinamičkog aspekta, također je sklopu kinetike elektroda i otpora u procesu elektrolize dan uvid u osnove elektrokemije. Svu navedenu teoriju je bilo važno usvojiti kako bi se mogao razumjeti princip rada elektrolizatora. Osim teoretskog dijela ovaj rad daje pregled povijesnog razvoja elektrolize odnosno elektrolizatora, kao i opise poznatih tehničkih koncepata njihove izvedbe . Tema ovog rada je proračun i konstrukcija elektrolizatora, konkretno alkalnog bipolarnog tipa. U petom poglavlju ( 5. Konstrukcija ) prikazana je izvedba bipolarnog elektrolizatora s tri elektrolitička članka u serijskoj vezi s obzirom na električnu struju i paralelnoj vezi s obzirom na protok elektrolita s pripadajućom tehničkom dokumentacijom. Osim konstrukcije proračunata je i potencijalna proizvodnja vodika elektrolizatora pod pretpostavkom da pojedini članak radi s padom napona od 2,3 V.

Integral Wheat Flour Based Biscuits as Sources of Phosphorus in Everyday Nutrition

Eight experimental integral wheat fl our based biscuits were prepared and investigated for total and bioavailable phosphorus content. Results were compared to the values obtained for classic white wheat fl our based biscuits in order to asses the impact of implantation of bran, different integral raw materials and fibers on the total phosphorus content and its availability. Since a study was conducted in the view of current trends of the excessive intake of this element in most of the developed countries, we expressed results obtained for total phosphorus content as percentages of allocated RDA values. Total phosphorus was determined by an offi cial AOAC method (AOAC 2001) and its bioavailability by an in vitro enzymatic method (Schwedt et al. 1998). Total phosphorus content of investigated samples ranged from 1.093 g kg-1 (biscuit based on type 500 wheat fl our) to 2.987 g kg-1 (biscuit enriched with integral wheat fl our and amaranth). Phosphorus availability was the highest in biscuit based on type 500 wheat fl our, as expected (86.1 %), and the lowest in the sample enriched with amaranth fl our (53.0 %), due to a very high phytic acid content. Considering revealed values of total phosphorus content and its bioavailability, we concluded that the richest source of this important macroelement was the sample enriched with soy flour providing 1.671 g kg-1 of available phosphorus

Raw Materials in Fibre Enriched Biscuits Production as Source of Total Phenols

Due to scientifically well documented health beneficial effects of dietary fibres and recommendations for an every day intake on an average of 30 g by food (DRI 2005), the confectionery industry has been increasingly engaged in the production of fibre enriched biscuits with the aim to offer such a product as a valuable constituent of proper nutrition and dietetic functional food intended for risky populations. Thereby, commercially available pure fibres or fibre-rich raw materials have been used for the enrichment of biscuits, prevalently pure fibres. To evaluate such products as functional food it is of interest to know how the choice of raw material for biscuit fibre enrichment influences the content of other health protecting compounds which commonly accompany fibres in plant material. With the aim of evaluating fibre rich biscuits as a source of total phenols depending on the origin of fibres, total phenols were determined spectrophotometrically by a modified Folin-Ciocalteau method (Gao et al. 2002) in ten experimentally baked biscuits based on wheat flour type 500 and type 1700 with or without different dietary fibres or fibre rich raw materials added instead of definite amount of white fl our. Results show that shares of total phenols and fibres in biscuits based on the wheat fl our depend on the type of the fl our. Biscuits with pure wheat and oats fibres added were the lowest in phenol content regardless on the highest amount of fibres (0.96 g kg-1 and 1.09 g kg-1, respectively); inulin and amaranth do not change essentially phenol content; apple fibres, soya fl our, and carob fl our enhance phenol content thereby carob fl our being the most effective giving biscuits 5.53 g total phenols kg-1

Mathematical Modelling and Parameter Estimation for the Design of Constructed Wetlands

Efficiency of waste water treatment in a subsurface constructed wetland depends on influent water quality, quality water effluent demand, climate conditions, substrate type and plants used. Therefore, the efficiency of the constructed wetlands that are designed and constructed according to the literature design parameters can be different then expected. The results of waste water treatment using a subsurface constructed wetland that is designed according to the literature data are presented. Experimental results and a mathematical model are described, and parameter estimation was conducted in order to determinate the reaction rate constant necessary for design of the constructed subsurface wetland that could be implemented in the continental area of Croatia. Achieved results indicate that a decrease of the constructed wetland area from 10 to 30% is possible

Nitrogen and Phosphorus Content, Hectoliter Weight and Yield Variations of Wheat Grain as Aff ected by Cropping Intensity

Public concerns over the potential environmental hazards of intensive agriculture have renewed an interest in the low-input nitrogen (N) fertilization practices for wheat (Triticum aestivum L.). A two-year study (2001 and 2002) was conducted to determine the infl uence of cropping intensity, namely the low-N (67 kg N ha-1) and high-N (194 kg N ha-1) input levels on the grain N and phosphorus (P) content, phytate-P (phytic acid and its salts), hectoliter weight and grain yield of three bread wheat cultivars widely grown in Croatia. Growing conditions significantly affected grain yields averaging 6641 kg ha-1 in the fi rst growing season and 8295 kg ha-1 in the following year. Despite an associated increase in the 1000-grain weights, the use of the low-N fertilization brought about a significant decrease in grain yield, hectoliter weight and grain N content in all cultivars by an average of 18.1%, 1.5% and 22.6%, respectively, when compared to the high-N fertilization level. The reductions in grain N content were consistent in both years regardless of variations in grain yields among three tested cultivars. Grain N content under the low-N fertilization averaged 17.1 g kg-1 only, which may limit its use for breadmaking. In contrast, grain P content was not affected by N fertilization or growing season and averaged 4.70 g kg-1 across all treatments. Absolutely small, but significant differences existed among cultivars for total grain P content, of which about 80% was in the form of phytate-P. A negative correlation between the 1000-grain weight and P content was found because of tendency toward lower P content in heavier grains. When compared to the high-N input, the low-N fertilization practices for wheat crop were associated with a significant decrease in grain yield and grain N content in all cultivars, but had no effect on grain P content regardless of cultivar

INULIN AND OLIGOFRUCTOSE IN DIET AND DISEASE PREVENTION

Inulin i oligofruktoza ubrajaju se u skupinu β (2-1)-fruktana te se međusobno razlikuju uglavnom prema stupnju polimerizacije. Inulin proizveden iz korijena cikorije obično ima stupanj polimerizacije 3-60. Kemijskom degradacijom ili kontroliranom enzimatskom hidrolizom inulina endoglikozidazama dobija se oligofruktoza sa stupnjem polimerizacije 2-20. Zbog dokazanog utjecaja inulina i oligofruktoze na brojne fiziološke i biokemijske procese danas se smatraju funkcionalnim sastavnicama namirnica čija konzumacija može bitno doprinjeti smanjenju rizika od pojave brojnih bolesti. Inulin i oligofruktoza su primarno prebiotici zbog svoje selektivne stimulacije rasta crijevnih bifidobakterija. Uz promjenu sastava crijevne mikroflore, fermentacijom inulina i oligofruktoze u kolonu ostvaruju se i dodatni učinci na epitel kao što su proliferacija kripti, promjena sastava mucina te modulacija nekih endokrinih i imunoloških funkcija epitela. U okvirima navedenih djelovanja, inulin i oligofruktoza također smanjuju incidenciju polipa i karcinoma debelog crijeva. Osim navedenog, bitno je naglasiti povoljan utjecaj inulina i oligofruktoze na apsorpciju nekih nutritivno važnih minerala, osobito Ca i Mg, čime se ostvaruje protektivan učinak kod osteoporoze te utjecaj inulina na smanjenje serumskih koncentracija triglicerida kod umjerene hipertrigliceridemije, vjerojatno mehanizmom inhibicije jetrene sinteze masnih kiselina. Zbog svega navedenog, inulin i oligofruktoza danas imaju široku primjenu u industriji funkcionalne hrane i dijetetskih proizvoda čemu dodatno pridonosi i činjenica da se zbog svojih tehnoloških karakteristika inulin (I) i oligofruktoza (OF) mogu koristititi kao zamjene za masti ili šećere i na taj način dodatno doprinjeti nutritivnoj vrijednosti i poboljšanim organoleptičkim svojstvima finalnog proizvoda.Inulin (I) and oligofructose (OF) are (2-1)-fructans with different degrees of polymerization (DP). Oligofructose (DP 2-20) is usually produced from chicory inulin (DP 3-60) using chemical degradation or controlled enzymatic hydrolysis with endoglycosidase enzymes. Nowadays they are being recognized as important functional food ingredients due to their ability to affect numerous physiological and biochemical processes resulting in maintaining health and reduction of the risk of certain diseases. They primarily act as prebiotics by stimulating the growth of intestinal bifidobacteria. In addition, they also induce changes in colonic epithelium stimulating proliferation in the crypts, changing the profile of mucine and modulating endocrine and immune functions reducing in such ways colon cancer incidence. Depending on their DP and daily dose, I and OF also promote the absorption of certain nutritionally important minerals to various extent, especially Ca and Mg, acting as antiosteoporotic agents. Animal studies demonstrate that inulin-type fructans affect the metabolism of lipids, primarily by decreasing hypertriglyceridaemia probably by decreasing the synthesis of triglycerides and fatty acids in liver. In addition to their beneficial health protecting properties, I and OF also possess very specific technological characteristics that enable their use in food industry as fat or sugar replacers in development of novel functional food products with improved nutritional and organoleptic characteristics

Legal Protection of Design Rights

U članku su objašnjeni osnovni pojmovi vezani uz Zakon o industrijskom vlasništvu, te prava autora dizajnerskog stvaralaštva i postupci stjecanja i zaštite tih prava u Republici Hrvatskoj putem Državnog zavoda za intelektualno vlasništvo.The paper explains some of the basic terms from the Croatian Industrial Property Law, and the rights of the author. It also describes the procedure for acquiring industrial design rights in Croatia through the Croatian Intellectual Property Office

Integracija elektroničkih dokumenata u spisovodstvo Državnog zavoda za intelektualno vlasništvo

Državni zavod za intelektualno vlasništvo svoje je uredsko poslovanje (spisovodstvo) prilagodio suvremenim tehnološkim dostignućima, te većinu svojih evidencija vodi u elektroničkom obliku. Također je u sustav evidentiranja ulazne i izlazne upravne i neupravne pošte uključio i skeniranje svih ulaznih i izlaznih akata, što je omogućilo potpunu integraciju elektroničih dokumenata u spisovodstvo Zavoda. Pri izradi ovog sustava evidentiranja korištene su metode i standardi koje je preporučila Svjetska organizacija za zaštitu intelektualnog vlasništva, pa će time biti omogućen i budući prihvat elektroničkih dokumenata u uspostavljenom sustavu za zaštitu intelektualnog vlasništva, te lakša adaptacija na zahtjeve koje postavljaju suvremeni uvjeti razvoja elektroničke trgovine i razmjene