Nonlinear magnetic response in ruthenocuprates

We have performed an investigation of the nonlinear magnetic response in ruthenocuprates. A negative, diverging-like peak at the main magnetic transition T_N in RuSr2RECu2O8 (RE = Gd, Y) indicates a possible canted antiferromagnetic order. Another well defined feature above T_N points to a blocking of superparamagnetic particles through the T^(-3) dependence of the third harmonic at higher temperatures. Below T_N a nondiverging peak appears, which is strongly affected by the addition of 10% of Cu ions in the RuO2 planes. In RuSr2RE(2-x)Ce(x)Cu2O10 the main magnetic transition T_M is accompanied by two characteristic temperatures in the third harmonic of the ac susceptibility, in agreement with recent studies from uSR and Mossbauer spectroscopy. We find that the spin-spin correlation temperature is the same in both families of ruthenocuprates.Comment: accepted for publication in EPJ

Ispitivanje nekih funkcionalnih svojstava mesa tolstolobika (Hypophthalmichthys molitrix Val.) i šarana Cyprinus carpio Lin

Water binding ability (WBA), held water (HW) and gel-forming properties of silver carp (Hypophthalmichthys molitrix Val) and carp (Cyprinus carpio Lin) meat were examined in this paper. Two variants of fish meat gels: A with 50% of meat and B with 60% of meat were examined at temperatures: 70 75, 80, 85 and 90°C. The variant A of silver carp meat gels has shown the maximum of WBA and HW at 80 oC, and the variant B at 75°C. In both variants of carp meat gels slow increase of WBA and HW with rise of temperature to 80°C was established. Silver carp meat gels have had better WBA than control gels (beef and poultry meat), and carp meat gels have better HW, but somewhat worse WBA than control gels. In gels of variant A of silver carp meat the highest module of elasticity (6.862 N/cm2) was found at thermal treatment at 85°C, but statistically significant differences in relation to other temperatures were not established. In variant B, with the rise of temperature, the module of elasticity increases; statistically significant differences were established among gels treated at 70 oC and others. Differences between variants A and B were statistically significant at all examined temperatures. Meat gels of silver carp have significantly lower module of elasticity compared to control gels. Under conditions of our experiment the module of elasticity of carp meat was below measuring limit.Nekonvencionalni tehnološki procesi, u preradi ribe, postaju sve zastupljeniji zahvaljujući mogućnostima koje pružaju u pogledu asortimana i racionalnom (ekonomičnom) iskorišćenju sirovine, i baziraju se na usitnjenom ribljem mesu ili surimiju kao sirovini. Kvalitet finalnog proizvoda uslovljen je funkcionalnim karakteristikama sirovine, kao što su sposobnost vezivanja vode i sposobnost geliranja i/ili uslovima toplotnog procesa. U ovom radu ispitivane su sposobnost vezivanja vode (SVV) i zadržavanja vode (HW) i sposobnost geliranja mesa belog tolstolobika (Hypophthalmichthys molitrix Val) i šarana (Cyprinus carpio Lin). SVV, HW i sposobnost geliranja varijanti gelova sa 50 i 60% mesa (A i B) ispitivane su na temperaturama: 70, 75, 80, 85 i 90°C. Varijanta A gelova od mesa tolstolobika pokazuje maksimalnu SVV i HW na 80°C, a varijanta B na 75°C. Obe varijante gelova od mesa šarana pokazuju blago povećanje SVV i HW sa porastom temperature do 80oC. Gelovi od mesa tolstolobika pokazuju znatno bolju SVV od kontrolnih gelova (goveđe i pileće meso), a gelovi od mesa šarana bolju HW, ali nešto lošiju SVV od kontrolnih gelova. Kod varijante gelova A od mesa tolstolobika najveći modul elastičnosti 6.862 N/cm2 utvrđen je pri toplotnoj obradi na 85oC, međutim, nisu utvrđene i statistički značajne razlike u odnosu na ostale temperature. Kod varijante B, sa povećanjem temperature povećava se i modul elastičnosti, statistički značajne razlike utvrđene su između gelova tretiranih na 70°C, i ostalih. Razlike između varijanti A i B su statistički značajne na svim ispitivanim temperaturama. Gelovi od mesa tolstolobika imaju statisički značajno manji modul elastičnosti, u odnosu na kontrolne gelove

Nonlinear magnetic response in ruthenocuprates

Abstract.: We have performed an investigation of the nonlinear magnetic response in ruthenocuprates. A negative, diverging-like peak at the main magnetic transition TN in RuSr2 RECu2O8 (RE = Gd, Y) indicates a possible canted antiferromagnetic order. Another well defined feature above TN points to a blocking of superparamagnetic particles through the T-3 dependence of the third harmonic at higher temperatures. Below TN a nondiverging peak appears, which is strongly affected by the addition of 10% of Cu ions in the RuO2 planes. In RuSr2 RE 2-xCexCu2O10 the main magnetic transition TM is accompanied by two characteristic temperatures in the third harmonic of the ac susceptibility, in agreement with recent studies from μSR and Mössbauer spectroscopy. We find that the spin-spin correlation temperature is the same in both families of ruthenocuprate

Efekti različitih tehnologija držanja na dobrobit prasadi u odgoju

During two consecutive years the effects of introduction of new technology i.e. boxes of new dimensions in rearing of piglets compared to conventional type of boxes, on animal welfare through production results were investigated and economical parameters relating to introduction of investigated technology in rearing piglets. Research was carried out on experimental pig farm of the Institute for Animal Husbandry, Belgrade-Zemun, Serbia. Obtained results demonstrated that introduction of new box, with 14 instead of 6 heads per box, influenced increase in gain by 7,9%, higher feed consumption by 6,7% and better feed conversion by 0,9% compared to production results in control group housed in conventional cages. In the structure of expenses, due to higher share of cost of material in total costs, also relative equal reduction of share of labour and depreciation costs for buildings and equipment, but also regardless of that, since cost of material is directly correlated to the production value, mentioned change can be characterized as positive, therefore by application of the new technology of piglet housing the amount of total cost decreased by over 7%, and in general total positive financial effect of 10,6% can be considered as very satisfactory. In general, obtained results showed that by application of new technology of piglet housing positive effects are achieved in regard to production and financial results, and also to welfare of this category of pigs.Tokom dve uzastopne godine istraživani su efekti uvođenja nove tehnologije odnosno boksa novih dimenzija u odgoju prasadi u poređenju sa klasičnim starim tipom boksa, na dobrobit životinja preko proizvodnih rezultata i ekonomske pokazatelje uvođenje ispitivane tehnologije kod prasadi u odgoju. Istraživanja su izvedena na eksperimentalnoj farmi svinja Instituta za stočarstvo, Beograd-Zemun u Srbiji. Dobijeni rezultati su pokazali da je uvođenje novog boksa, sa 14 u odnosu na 6 grla u boksu, imalo efekte izražene boljim prirastom za 7,9%, većom konzumacjom hrane za 6,7% i povoljnijom konverzijom hrane za 0,9% u poređenju proizvodnim rezultatima kod kontrolne grupe držane u klasičnim kavezima. U strukturi troškova većim udelom troškova materijala u ukupnim troškovima, zbog relativno ravnomernog smanjenja udela troškova zarada i troškova amortizacije objekata i opreme, i bez obzira na to, budući da utrošak materijala ima direktnu korelaciju sa vrednosti proizvodnje navedenu promenu je moguće okarakterisati kao pozitivnu tako da se primenom nove tehnologije držanja prasadi iznos ukupnih troškova smanjio za preko 7%, te se u celini ostvareni ukupan pozitivan finansijski rezultat od 10,6% može tumačiti kao veoma zadovoljavajući, U celini dobijeni rezultati su pokazali da se primenom nove tehnologije držanja prasadi u odgoju ostvaruju pozitivni efekti na proizvodne i finansijske rezultate a time i na dobrobit kod ove kategorije svinja

Dissipation processes in the insulating skyrmion compound Cu2OSeO3

We present a detailed study of the phase diagram surrounding the skyrmion lattice (SkL) phase of Cu2OSe2O3 using high-precision magnetic ac susceptibility measurements. An extensive investigation of transition dynamics around the SkL phase using the imaginary component of the susceptibility revealed that at the conical-to-SkL transition a broad dissipation region exists with a complex frequency dependence. The analysis of the observed behavior within the SkL phase indicates a distribution of relaxation times intrinsically related to SkL. At the SkL-to-paramagnet transition a narrow first-order peak is found that exhibits a strong frequency and magnetic field dependence. Surprisingly, very similar dependence has been discovered for the first-order transition below the SkL phase, i.e. where the system enters the helical and conical state(s), indicating similar processes across the order-disorder transition.Comment: Accepted for publication in PR

Sadržaj holesterola u mesu pojedinih Cyprinidae

The aim of this paper was to examine cholesterol content in meat of five Cyprinidae species: white bream (Bllica bjoerkna L.), carp bream (Abramis brama L.), baltic vimba (Vimba vimba carinata Pallas), zope (Abramis balerus L.) and crucian carp (Carassius carassius gibelio Bloch) from the river Danube. Cholesterol content was examined in the function of season factor and individual weight. Cholesterol concentration in meat of white bream carp bream, baltic vimba, zope and crucian carp is on average level below 20 mg/100 g of meat, which makes meat of these fish species nutritively very valuable. Cholesterol content is variable during the season. Its concentration in meat and in lipids is lowest during spring, during summer it increases and during autumn decreases, except in meat of white bream. Body weight has influence on cholesterol content when its concentration is expressed as % of cholesterol in lipids. Its content in lipids decreases with increasing of individual weight, except in meat of carp bream.Jedan od najznačajnijih faktora rizika koji dovodi do razvoja ateroskleroze i bolesti srca i krvnih sudova je povišen nivo holesterola u krvi. Stoga je cilj ovog rada bio da se ispita sadržaj holesterola u mesu pet vrsta Ciprinida poreklom iz reke Dunav, u funkciji sezonskog faktora i mase jedinki. Sadržaj holesterola u mesu, svih ispitivanih vrsta riba, je na niskom nivou. Njegova prosečna vrednost tokom perioda proleće-jesen kreće se od 14.85 mg/100g u mesu špicera, do 31.40 mg/100g u mesu krupatice. Sadržaj holesterola, u mesu deverike, plavonosa, špicera i babuške je ispod 20 mg/100g mesa, što su znatno niže vrednosti no u mesu toplokrvnih životinja. Koncentracija holesterola u mesu i u masti najmanja je tokom proleća, tokom leta se povećava, a u toku jeseni smanjuje, osim u mesu krupatice. Masa trupa utiče na sadržaj holesterola u slučaju kada je njegova koncentracija iskazana kao % holesterola u masti. Njegov sadržaj u masti smanjuje se sa povećanjem mase jedinki, osim u mesu deverike

Polymerization quality testing of composite resins cured by led light source

The quality of interface between composite resin materials and hard dental tissues is highly dependent on the polymerization light source. Newly developed blue light- emitting diode units for light polymerization of dental restorative materials are the most innovative light source technology in dentistry nowadays. The aim of this work was to estimate the depth of cure of five different light-activating composite resins exposed to different irradiation times (5s, 10s, 20s and 40s) when the experimental LED light source was used. The tested materials were: Tetric Ceram (Vivadent), Point 4 (Kerr), Admira (VOCO), Filtek Z250 (3M) and Diamond Lite (DRM Lab., Inc). The depth of cure testing was determined using a penetrometer. Results after 40s curing time were as following: the deepest depth of cure was achieved after application of Filtek Z 250, Diamond Lite Point 4 and Tetric Ceram. For the restorative material Admira was found the lowest depth of cure for the light exposure of 40s. An experimental LED light source achieved a sufficient depth of cure (over 2 mm) for all tested materials after curing time of 10s. The polymerization light source spectral distribution should be considered in addition to irradiance as a depth of cure indicator

Microstructure evolution and phase transition in Er doped BaTiO3 ceramics

The Er doped BaTiO3 ceramics, with different Er2O3 content, ranging from 0.01 to 1.0 wt% Er, were investigated regarding their microstructural and dielectric characteristics in this paper. Doped BaTiO3 were prepared by using conventional method of solid state sintering at 1380 °C for four hours. SEM analysis of Er/BaTiO3 doped ceramics showed that in samples doped with a rareearth ions low level, the grain size ranged from 20-40 μm, while with the higher dopant concentration the abnormal grain growth is inhibited and the grain size ranged between 2-10μm. Dielectric measurements were carried out as a function of temperature up to180°C at different frequencies. The low doped samples sintered at 1380 °C, display the high value of dielectric permittivity at room temperature, 2160 for 0.01 Er/BaTiO3. A nearly flat permittivity-response was obtained in specimens with higher additive content. Using a Curie-Weiss low and modified Curie-Weiss low the Curie constant C, Curie temperature Tc and a critical exponent of nonlinearity γ were calculated. The Curie temperature of doped samples were ranged from 126 to 130 °C. The Curie constant for all series of samples decrease with increase of dopant concentration and the lowest values were mesured from samples doped with 0.01 wt% of aditive. The obtained value of γ pointed out that the specimens have almost sharp phase transition

Методологија за синтезу реактора заснована на концептима интензификације процеса и примени метода оптимизације

In this Ph.D. thesis, a new methodology for Reactor Synthesis Based on Process Intensification Concepts and Application of Optimization Methods (ReSyPIO) is presented and applied to two different cases. In Chapter 1: Introduction – Motivation and Objectives, the motive for the research is presented, and Hypotheses are formulated. The ReSyPIO methodology that rests upon these Hypotheses and consists of three consecutive stages is briefly described in this Chapter. The first stage encapsulates all present phases and phenomena inside the reactor functional building block, called module. Modules come as a direct result of a conceptual representation of the analyzed system. In the second stage, modules are further segmented if needed and interconnected, creating a reactor superstructure that is mathematically described for all desirable operating regimes. In the last stage of the ReSyPIO methodology, the optimal structure, operating conditions, and the operational regime are determined with the use of rigorous optimization. All three stages of the ReSyPIO methodology have a backflow, meaning that if analysis leads to impractical, nonfunctional or inefficient results, modifications in reactor superstructure and modules can be made. The objective is to conceptually and numerically derive the most efficient reactor structure and a set of operating conditions that would be used as a starting point in the future reactor design. Chapter 2: Literature Review is used to cover and review the most important research published in the area of Process Intensification and different Process System Engineering techniques. Different approaches and studies present in academia are highlighted and their elements compared with the presented ReSyPIO methodology with the accent on its advantages and contribution to the engineering science community.Also, in this Chapter, an array of well researched analytical and numerical approaches is presented that could be used in the future to strengthen the ReSyPIO methodology further and facilitate its easier application. In Chapter 3: Description of the ReSyPIO Methodology Reactor Synthesis based on Process Intensification and Optimization of Superstructure is explained in detail, with a graphical representation of the main building block, called Phenomenological Module. A general explanation is given on how to form a reactor superstructure and mathematically describe it with sets of material and energy balance equations that correspond to a number of present phases and components in the system. The ReSyPIO methodology is first applied to a generic case of two parallel reactions in Chapter 4, called Application of the ReSyPIO Methodology on a Generic Reaction Case. The case corresponds to two parallel reactions that could be found in the fine chemical industry. The reactions are endothermic and slow with the undesired product. After the application of the ReSyPIO methodology, an optimal reactor structure consisting of a segmented module with 17 side inlets for the reactant and heat source is obtained. It is recommended for the reactor to work in a continuous steady-state mode as the dynamic operation would not lead to a sufficient increase in reactor efficiency...У овој докторској дисертацији је представљена и примењена нова методологија за синтезу реактора заснована на концептима интензификације процеса и примени различитих оптимизационих техника (Reactor Synthesis Based on Process Intensification Concepts and Application of Optimization Methods – ReSyPIO). У поглављу Увод – Мотивација и циљеви, формиране су хипотезе на којима почива ReSyPIO методологија и дата је мотивација за истраживање. ReSyPIO методологија је укратко представљена и описана кроз три узастопне етапе. Прва етапа уоквирава све присутне фазе и феномене у реактору унутар функционалних градивних јединица, названих модули. Модули представљају резултат концептуалног приказа анализираног система. У другој етапи, модули се по потреби могу даље поделити у сегменте и међусобно повезати, креирајући суперструктуру реактора. Суперструктура је математички описана за све режиме рада реактора од интереса. У последњој етапи ReSyPIO методологије, оптимална структура, услови и режим рада реактора су одређени применом ригорозне оптимизације. Све три етапе ReSyPIO методологије имају повратни ток, што значи да уколико анализа води ка непрактичним, нефункционалним или неефикасним решењима, модификација математичког модела, суперструктуре и/или модула је могућа. Циљ примене ReSyPIO методологије је да се концептуалним и нумеричким приступом дође до оптималне препоруке за структуру реактора, оперативне услове и режим рада, која би била почетна претпоставка у будућем дизајну уређаја. Преглед литературе даје опис и приказ свих истраживања од интереса, из области Интензификације процеса и Теорије и анализе процесних система. Наглашени су различити приступи и студије присутне у истраживачкојзаједници, а њихови елементи упоређени са представљеном ReSyPIO методологијом са акцентом на предностима и научном доприносу. У овом поглављу је дат и низ добро истражених аналитичких и нумеричких приступа који би могли да буду коришћени у оквиру ReSyPIO методологије и олакшају њену примену. У поглављу Опис ReSyPIO методологије, је детаљно објашњена синтеза реактора заснована на концептима интензификације процеса и оптимизацији суперструктуре. Прво је дата процедура за графичку и концептуалну репрезентацију система, преко главних градивних јединица, феноменолошких модула. Потом је објашњено како се креира суперструктура реактора. На крају је дат уопштен поступак за математички опис суперструктуре преко скупова једначина материјалног и енергетског биланса, чији број зависи од броја присутних фаза и компонената у систему. ReSyPIO методологија је први пут примењена на случају две генеричке паралелне реакције у поглављу под називом Примена ReSyPIO методологије на случају генеричке реакције. Овај случај одговара реакцијама које се могу наћи у индустрији финих хемикалија. Реакције су ендотермне и споре, при чему је кинетички фаворизовано креирање нежељеног производа. Након примене ReSyPIO методологије, добијена је оптимална структура реактора која се састоји од сегментисаног модула са 17 улаза за извор топлоте и реактант који се дозира. Предложено је да реактор ради континуално, у стационарном режиму рада, јер би динамички режим рада резултовао недовољним повећањем ефикасности реактора..