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Analysis of adaptive and robust control of a modern fighter aircraft
No full textPredmet ovog rada je izrada sustava stabilizacije za borbeni zrakoplov nalik na Dassault Rafale u podzvučnom režimu leta korištenjem optimalne LQR metode. Dinamički model zrakoplova promatran je kao model sa šest stupnjeva slobode i zatim je lineariziran u više radnih točaka te je korišten zapis u prostoru stanja, odvojen za uzdužno i bočno gibanje. Za svaku kombinaciju Machovog broja i visine izvedena je sinteza LQ regulatora, a rezultati su objedinjeni strategijom promjenjivih pojačanja. U svrhu ocjene kvalitete upravljanja analizirani su odzivi sustava stabilizacije na poremećaje i primijenjeni kriteriji iz vojnog standarda MIL 8785C. Rezultati pokazuju da LQ regulatori uz interpolirana pojačanja osiguravaju stabilizaciju sustava i zadovoljavaju postavljene zahtjeve odziva sustava i ocjene kvalitete upravljanja.The subject of this thesis is the development of a stabilization system for a fighter aircraft resembling the Dassault Rafale, operating in the subsonic flight regime, using the optimal LQR method. The aircraft’s dynamic model was considered as a six degrees-of-freedom system and subsequently linearized at multiple operating points, using the state-space representation, separately for longitudinal and lateral-directional motion. For each combination of Mach number and altitude, an LQ regulator was synthesized, and the results were combined using a variable gain strategy. To evaluate the control quality, the stabilization system’s response to disturbances was analyzed using the criteria defined by the MIL-8785C military standard. The results demonstrate that LQ regulators with interpolated gains ensure system stabilization and meet the prescribed response and handling quality requirements
Zadovoljstvo učenika dvojezičnom nastavom na francuskom jeziku u hrvatskim školama
No full textCette recherche examine la satisfaction des élèves envers le programme bilingue en français dans les écoles croates, en se concentrant sur leurs progrès et compétences linguistiques. Une approche mixte, utilisant des questionnaires quantitatifs et qualitatifs, a été adoptée. Les résultats montrent que la principale motivation des élèves était d'améliorer leur niveau de français. À la fin du programme, la majorité des élèves étaient satisfaits de leurs compétences linguistiques. Bien que des critiques aient été émises, telles que le manque de communication orale et de matériel pédagogique en français, les élèves ont rapporté un enrichissement de leur vocabulaire et une meilleure compréhension de la culture française. Cependant, les notes finales n'ont pas montré une amélioration significative. En somme, la recherche a permis de mettre en lumière les réussites et les défis du programme.Ovo istraživanje ispituje zadovoljstvo učenika francuskim dvojezičnim programom u hrvatskim školama te njihov jezični napredak i vještine. Korišten je mješoviti pristup putem kvantitativnih i kvalitativnih upitnika. Rezultati pokazuju da je glavna motivacija učenika bila poboljšati razinu francuskog jezika te da su na kraju programa većinom bili zadovoljni svojim znanjem jezika. Iako je bilo kritika, poput nedostatka usmene komunikacije i nastavnih materijala na francuskom, učenici su istaknuli napredak u vokabularu i boljem razumijevanju francuske kulture. Međutim, konačne ocjene nisu pokazale značajno poboljšanje. Ukratko, istraživanje je uspješno prikazalo uspjehe i izazove programa
Anaysis of healthy food availability and product placement in different retail formats
No full textNačin na koji je zdrava hrana dostupna i pozicionirana u prodavaonicama može značajno utjecati na prehrambene izbore potrošača. Ovaj rad istražuje ulogu maloprodajne ponude kao čimbenika koji pridonosi oblikovanju prehrambenih navika, s naglaskom na dostupnost i pozicioniranje zdrave hrane. Istraživanje je provedeno metodom promatranja u odabranim maloprodajnim oblicima u Zagrebu. Istraživanje je uključivalo bilježenje fizičkog rasporeda proizvoda, omjera zdrave i nezdrave hrane, cijena te jasnoće označavanja proizvoda. Rezultati pokazuju da zdrava hrana često nije dovoljno vidljiva, zauzima manji udio prostora i često je skuplja u usporedbi s nezdravim proizvodima. Rad ukazuje na izazove u maloprodaji te mogućnosti za poboljšanje dostupnosti zdravijih prehrambenih izbora.The availability and positioning of healthy food in stores can significantly influence consumers dietary choices and thereby shape their eating habits. This paper investigates the role of retail offerings as a factor contributing to the formation of dietary habits, with a focus on the availability and positioning of healthy food. The research was conducted using an observational method in selected retail formats in Zagreb. The study involved recording the physical arrangement of products, the ratio of healthy to unhealthy food, prices, and the clarity of product labeling. The results show that healthy food is often not sufficiently visible, occupies a smaller share of shelf space, and is often more expensive compared to unhealthy products. The paper highlights challenges in retail and suggests possibilities for improving the availability of healthier food choices
Die casting mould design for an aluminium alloy engine mount
No full textVisokotlačno lijevanje je značajan proizvodni postupak koji se primjenjuje u raznim industrijama. Bitna komponenta postupka visokotlačnog lijevanja je kalup. Oblik i karakteristike kalupa utječu na značajke konačnog proizvoda.
U uvodnom dijelu ovog rada dan je kratak pregled povijesnog razvoja postupka lijevanja, a zatim su ukratko pojašnjeni sami postupci lijevanja.
Nakon pokrivenog teorijskog dijela lijevanja, prikazani su interni standardi konstrukcijskih rješenja komponenata kalupa. Za sve bitne komponente objašnjena je njihova uloga u kalupu te u samom procesu lijevanja. Za sve zahtjevnije komponente te za komponente kalupa za koje se smatralo potrebnim, dat je primjer konstrukcijskog rješenja.
U nastavku prikazani su zahtjevi procesa lijevanja, zahtjevi za odljevak te zahtjevi za stroj. U ovom dijelu je također verificiran sam model te izrađeni su ulijevna grana i preljevni džepovi s odzračnicima. Provedeni su svi neophodni proračuni za ovaj korak.
Na kraju ovog rada prikazane su standardne komponente koje su se koristile u projektiranju ovog kalupa. Također, prikazani su problemi koji su se javili u probnom lijevanju te način na koji su otklonjeni.
Sveukupnu nacrtnu dokumentaciju ovog kalupa moguće je pronaći na kraju ovog rada.Die casting is an important manufacturing process used in various industries. An essential component of the high-pressure die casting process is the mold. The shape and characteristics of the mold affect the characteristics of the final product.
In the introductory part of this paper, a brief overview of the historical development of the casting process is given, and then the casting processes themselves are briefly explained.
After the theoretical part of casting has been covered, the internal standards of the structural solutions of the mold components are presented. For all important components, their role in the mold and in the casting process itself is explained. For all the more complex components, and for the mold components for which it was necessary, an example of the design solution is given.
Below are the casting process requirements, casting requirements, and machine requirements. In this part, the model itself was also verified; runner, gate and overflow with vents were made. All necessary calculations for this step were performed.
At the end of this paper, the standard components used in the design of this mold are shown. Also, the problems that occurred in the test casting and the way in which they were eliminated are presented.
The entire documentation of this mold can be found at the end of this thesis
Effect of artificial sweeteners on the insulin signaling pathway of human neuroblastoma cells SH-SY5Y
No full textUvod: Neurodegenerativne bolesti predstavljaju sve veći zdravstveni problem u populacijama zemalja razvijenog svijeta. Nekoliko istraživanja ukazuje na povezanost inzulinske rezistencije s razvojem Alzheimerove i Parkinsonove bolesti. Sukraloza podiže razinu glukoze i inzulina kod pretilih ženama. Vrlo male doze natrijeva ciklamata mogu poremetiti diferencijaciju i proliferaciju osteoblasta.
Ciljevi: Ciljevi ovog istraživanja su bili ispitati učinke tretmana triju koncentracija natrijeva ciklamata (1 mM, 10 mM, 100 mM) i sukraloze (0,2 mM, 2 mM, 20 mM) samostalno, te u kombinacijama s inzulinom i levodopom na preživljenje, inzulinski signalni put i metabolički odgovor diferenciranih stanica ljudskog neuroblastoma.
Materijali i metode: Diferencirane SH-SY5Y stanice su tretirane sladilima i dodatnim tretmanima. Citotoksičan učinak tretmana određen je MTT testom. Aktivnost inzulinskog signalnog puta ispitala se Western blot metodom. Ukupni učinak tretmana na metabolički odgovor tretiranih stanica ispitan je MALDI-TOF MS metodom.
Rezultati: Stanice tretirane sukralozom u sve tri koncentracije gdje je kao dodatni tretman korištena i levodopa imale su značajno veće preživljenje u odnosu na netretiranu ili inzulinom tretiranu kontrolnu skupinu. Natrijev ciklamat je na preživljenje stanica imao o koncentraciji ovisan učinak. Najmanja koncentracija značajno je povećala preživljenje stanice neovisno o dodatnom tretmanu inzulinom ili levodopom.
Zaključak: Sukraloza i natrijev ciklamat u kombinaciji s inzulinom i levodopom sprječavaju apoptozu diferenciranih stanica ljudskog neuroblastoma u određenim koncentracijama putem inzulinskog signalnog puta. Međutim, potrebno je istražiti učinak ovih sladila na ostale metaboličke puteve.Introduction: Neurodegenerative diseases represent an increasing health problem in the populations of countries in the Western world. Several studies indicate a connection between insulin resistance and the development of Alzheimer's and Parkinson's diseases. Sucralose raises glucose and insulin levels in obese women. Very small doses of sodium cyclamate can disrupt the differentiation and proliferation of osteoblasts.
Objectives: The objectives of this research were to examine the effects of three concentrations of sodium cyclamate (1 mM, 10 mM, 100 mM) and sucralose (0,2 mM, 2 mM, 20 mM) independently and in combination with insulin and levodopa on survival, insulin signaling pathway and metabolic response of differentiated human neuroblastoma cells.
Material and methods: Differentiated SH-SY5Y cells were treated with sweeteners and additional treatments. The cytotoxic effect of the treatment was determined by the MTT test. The activity of the insulin signaling pathway was examined using the Western blot method. The overall effect on the metabolic response of the treated cells was determined by the MALDI-TOF MS method.
Results: Cells treated with sucralose in all three concentrations, where levodopa was also used as an additional treatment, had significantly higher survival compared to the untreated or insulin-treated control group. Sodium cyclamate had a concentration-dependent effect on SH-SY5Y cells survival. The lowest concentration significantly increased cell survival independent of additional treatment with insulin or levodopa.
Conclusion: Sucralose and sodium cyclamate in combination with insulin and levodopa prevent apoptosis of differentiated human neuroblastoma cells in certain concentrations via the insulin signaling pathway. However, it is necessary to investigate the effect of these sweeteners on other metabolic pathways
Impeller type impact on wastewater treatment using the hybrid process of electrocoagulation and zeolite : diploma thesis
No full textU ovom radu provedena su ispitivanja hibridnog procesa obrade otpadne vode elektrokoagulacijom uz dodatak sintetskog zeolita granulacije < 40 µm uz primjenu operacije miješanja korištenjem različitog tipa miješala, odnosno turbinskog tipa miješala s ravnim lopaticama SBT (engl. straight blade turbine) i turbinskog tipa miješala s lopaticama pod nagibom PBT (engl. pitched blade turbine) miješala pri različitim vremenima kontakta od 30, 20 i 10 minuta. Eksperimenti su izvedeni u elektrokemijskoj ćeliji s Al i Fe elektrodama, pri konstantnoj gustoći struje od 0,0182 A/cm 2 , udaljenosti elektroda od 3 cm, dodatkom elektrolita (0,5 g/L) i zeolita (15 g/L). Tijekom eksperimenta pratila se pH vrijednosti, temperatura i električna vodljivost, dok su kemijska potrošnja kisika, mutnoća i ukupni isparni ostatak određeni na početku i na kraju procesa. Nakon provedbe hibridnog procesa ispitane su promjene mase elektroda te je proveden test taloženja suspenzija. Rezultati su pokazali da je za obradu otpadne vode najbolje upotrijebiti elektrokoagulaciju bez dodatka zeolita uz primjenu Fe elektroda te uz primjenu PBT miješala. Izračun operativnih troškova pokazao je da dodatak zeolita i duže vrijeme provedbe procesa pridonosi boljem otapanju elektroda, neovisno o tipu miješala.This study examined a hybrid wastewater treatment process through electrocoagulation using synthetic zeolite with a particle size of < 40 µm by applying mixing operations using different impeller types: SBT (straight blade turbine) and PBT (pitched blade turbine). The experiments involved varying contact times of 30, 20, and 10 minutes. They were conducted in an electrochemical cell with aluminum and iron electrodes, at a constant current density of 0,0182 A/cm², an electrode spacing of 3 cm, and the addition of electrolyte (0,5 g/L) and zeolite (15 g/L). During the experiments pH values, temperature, as well as electrical conductivity were monitored. Chemical oxygen demand, turbidity, and total solids were determined at the beginning and at the end of the process. After the hybrid process was completed, changes in electrode mass and the sedimentation of suspensions were examined. The results indicated that the most effective wastewater treatment was achieved through electrocoagulation without the addition of zeolite, using iron electrodes and PBT impeller. The operational cost calculations showed that the addition of zeolite and longer processing time enhances electrode dissolution, regardless of the impeller type
The Contribution of the Analysis of Financial Statements and Non-Financial Statements – Case Study of the Company KEV d.d. Using Pivot Analysis for the Period from 2020 to 2022
No full textOvim diplomskim radom analizira se doprinos financijskih i nefinancijskih izvještaja u procjeni uspješnosti poslovanja poduzeća Končar Električna Vozila d.d. u razdoblju od 2020. do 2022. godine. Primjeno, Pivot analize i naprednih metoda poslovne inteligencije, istražena je struktura bilance, računa dobiti i gubitka te novčanog toka, uz poseban naglasak na ključne financijske pokazatelje. Osim financijskih izvještaja, analizirani su i nefinancijski aspekti poslovanja, uključujući ekološki otisak, društvenu odgovornost i upravljačke strukture, kako bi se dobila sveobuhvatna slika poslovanja. Konačni rezultati istraživanja pokazuju trendove rasta prihoda i poslovne ekspanzije poduzeća, uz određene izazove u upravljanju troškovima i likvidnošću. Zaključuje se da integrirana analiza financijskih i nefinancijskih izvještaja omogućava bolje strateško odlučivanje te povećava transparentnost i održivost poslovanjaThis graduate thesis analyzes the contribution of financial and non-financial reports in assessing the business performance of the company Končar Električna Vozila d.d. during the period from 2020 to 2022. By applying Pivot analyses and advanced business intelligence methods, the structure of the balance sheet, income statement, and cash flow statement was examined, with particular emphasis on key financial indicators. In addition to financial reports, non-financial aspects of business operations were also analyzed, including environmental footprint, social responsibility, and governance structures, in order to obtain a comprehensive view of the company's performance. The final research results indicate trends of revenue growth and business expansion, alongside certain challenges in cost management and liquidity. It is concluded that an integrated analysis of financial and non-financial reports enables better strategic decision-making and enhances transparency and business sustainability
Flow spiral freezer for food products
No full textU ovom radu proučavaju se tehnologije konzerviranja hrane zamrzavanjem s fokusom na
zamrzavanje u struji hladnog zraka. Fizikalno će se objasniti zašto su upravo IQF zamrzivači,
među koje spada i protočni spiralni tunel za duboko zamrzavanje, jedni od najkorištenijih
zamrzivača u prehrambenoj industriji. Nadalje se objašnjavaju ključne komponente spiralnog
zamrzivača te se za njega određuje toplinsko opterećenje. Naglasak rada je na osmišljavanju
rashladnog procesa za zamrzavanje 2000 kg/h piletine za postrojenje u Varaždinu. Rad sadržava
termodinamički proračun komponenata rashladnog sustava te odabir istih.This thesis examines conservation technologies with a focus on freezing in a cold air stream. It
will physically explain why IQF freezers, including the flow spiral tunnel for deep freezing, are
among the most widely used freezers in the food industry. Furthermore, the key components of
the spiral freezer are explained, and its thermal load is determined. The focus of this paper is on
designing the refrigeration process for the required production capacity of 2000 kg/h of chicken
for the facility in Varaždin. The paper includes a thermodynamic calculation of the refrigeration
system components and their selection
Must cooling of white grapes during fermentation
No full textU ovom završnom radu razrađena je tema procesa hlađenja mošta od bijelog grožđa za vrijeme fermentacije. U uvodnom dijelu opisan je proces proizvodnje vina te važnost primjene sustava hlađenja u procesu alkoholne fermentacije. U nastavku je opisan proces hlađenja te su navedene radne tvari koje se primjenjuju u tehnici hlađenja. Također su navedene vrste hlađenja kojima se kontrolira temperatura mošta pri provođenju procesa fermentacije. Zatim je proveden termodinamički proračun rashladnog uređaja za posredno hlađenje mošta u posudama od nehrđajućeg čelika, volumena 2000 litara 2 komada i 1000 litara 3 komada. Uređaj za hlađenje se sastoji od četiri osnovne komponente, to su kompresor, kondenzator, prigušni element te isparivač. Termodinamički proračun obuhvaća proračun isparivača te proračun cjevovoda. U završnom dijelu rada je proračunata cirkulacijska pumpa za posredni prijenosnik energije te su prikazane sheme spajanja, automatska regulacija i dispozicijski crtež rashladnog postrojenja.This final thesis covers the cooling process of white grapes during fermentation. The introduction describes winemaking and the importance of employing cooling systems in the process of alcoholic fermentation. The paper provides a description of the cooling process, as well as a list of refrigerants that are used in the cooling technique and types of cooling systems used to control the must’s temperature during fermentation. Furthermore, a thermodynamic calculation was made for indirect cooling of must in stainless steel containers - two of which had a volume of 2000 liters and three a volume of 1000 liters. A cooling device consists of four basic components: a compressor, a condenser, an expansion valve, and an evaporator. The thermodynamic calculation includes calculations for the evaporator and the pipeline. The paper concludes with a calculation of the circulation pump for the indirect energy transporter, and it includes diagrams that show connecting parts, automatic regulation, and a technical drawing of the cooling installation
The impact of low temperatures on material toughness and the safety of structures
No full textIstraživanje utjecaja niskih temperatura na žilavost materijala od ključne je važnosti za sigurnost raznih konstrukcija izloženih ekstremnim okolišnim i klimatskim uvjetima. Neugodna iskustva iz povijesti dokaz su posljedica do kojih može doći uslijed zanemarivanja ovog bitnog svojstva materijala. U početnom dijelu rada najprije je definirana žilavost kao mehaničko svojstvo materijala, navedeni su faktori koji utječu na njenu promjenu te istaknuta temperatura kao jedan od najbitnijih faktora. Dalje je dan pregled metoda kojima se ista određuje, te kako se ispituje utjecaj temperature na nju. Dan je pregled povijesnih slučajeva nesreća uzrokovanih padom žilavosti uslijed djelovanja niskih temperatura, kao što su puknuća Liberty klase brodova, Titanika te urušavanje Silver Bridgea mosta. U eksperimentalnom dijelu rada dan je i primjer određivanja utjecaja pada temperature na konstrukcijski čelik S355 J2, koji se često koristi u raznim konstrukcijama, a u danom slučaju za izradu sprega koje se koriste pri konstrukciji i rekonstrukciji mostova i drugih građevina. Ispitivanja su provedena u rasponu temperatura od 20 do -75 °C, kako bi se utvrdila prijelazna temperatura materijala u osnovnom stanju te u zoni utjecaja topline nastalom prilikom zavarivanja konstrukcijskog elementa. Rezultati su pokazali određena odstupanja u žilavosti materijala u zoni zavara u usporedbi s osnovnim materijalom. Neovisno od toga istraživanje je potvrdilo sukladnost konstrukcijskog elementa sprege s propisanim vrijednostima u standardima. Time je potvrđeno da nema opasnosti od krhkog loma pri korištenju ovog materijala za izradu sprega u danim temperaturnim uvjetima.Research into the effects of low temperatures on the toughness of materials is of crucial importance for the safety of various structures exposed to extreme environmental and climatic conditions. Unpleasant experiences from history show the consequences of neglecting this important material property. In the first part of this graduation thesis, the toughness of materials is defined as a mechanical property of a material, the factors that influence its change are listed, and temperature is emphasized as one of the most important factors. Furthermore, an overview of the methods used to determine toughness is then given and the influence of temperature is described. Further, through work, an overview is given of historical cases of accidents caused by a decrease in toughness due to exposure to low temperatures, such as the cracking of Liberty-class ships, the Titanic, and the collapse of the Silver Bridge. The experimental part gives an example of determining the influence of a temperature drop on the structural steel S355 J2, which is commonly used in various constructions, in this case for the production of joints used in the construction and reconstruction of bridges and other buildings. The tests were conducted in the temperature range from 20 to -75 °C, to determine the material's transition temperature in the initial state and in the heat-affected zone by the heat generated during the welding of the structural element. The results showed certain deviations in material toughness in the weld zone compared to the base material. Regardless of this, the test confirmed that the structural element of the coupling complied with the values specified in the standards. This confirmed that there is no risk of brittle fracture when using this material for the manufacture of couplings under the given temperature conditions