The influence of domain structure on the variation of coercive field and maximum magnetization of Fe_77.5B_22.5 amorphous alloy

The magnetic hysteresis of Fe_77.5B_22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (H_c), maximum magnetization (M_m) and remanent magnetization (M_r) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (M_s) and that the interaction between two domain structures plays an important role in enhanced increase of H_c on M_m > 0.5 M_s. The frequency dependence of parameters of the hysteresis curve is briefly discussed

Utjecaj domenske strukture na ovisnost koercitivnog polja i maksimalne magnetizacije amorfne slitine Fe77.5B22.5

The magnetic hysteresis of Fe77.5B22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (Hc), maximum magnetization (Mm) and remanent magnetization (Mr) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (Ms) and that the interaction between two domain structures plays an important role in enhanced increase of Hc on Mm > 0.5 Ms. The frequency dependence of parameters of the hysteresis curve is briefly discussed.Indukcijskom metodom mjerene su krivulje magnetizacije amorfne vrpce Fe77.5B22.5. Ovisnosti koercitivnog polja (Hc ), maksimalne magnetizacije (Mm ) i remanentne magnetizacije (Mr) mogu se objasniti dvostrukom domenskom strukturom karakterističnom za ovakve uzorke. Analiza mjerenja pokazuje da su unutrašnje domene odgovorne za magnetizaciju do 65% magnetizacije zasićenja (Ms) te da interakcija između dviju domenskih struktura igra važnu ulogu pri ubrzanom rastu Hc pri Mm > 0.5 Ms. Razmatrana je i ovisnost parametara krivulje histereze o frekvenciji

Utjecaj domenske strukture na ovisnost koercitivnog polja i maksimalne magnetizacije amorfne slitine Fe77.5B22.5

The magnetic hysteresis of Fe77.5B22.5 amorphous ribbon has been studied by the induction method. The results for coercive field (Hc), maximum magnetization (Mm) and remanent magnetization (Mr) are explained by the twofold domain structure of amorphous alloys in form of ribbons. The analysis of the measurements shows that the inner domains are responsible for the magnetization up to about 65% saturation magnetization (Ms) and that the interaction between two domain structures plays an important role in enhanced increase of Hc on Mm > 0.5 Ms. The frequency dependence of parameters of the hysteresis curve is briefly discussed.Indukcijskom metodom mjerene su krivulje magnetizacije amorfne vrpce Fe77.5B22.5. Ovisnosti koercitivnog polja (Hc ), maksimalne magnetizacije (Mm ) i remanentne magnetizacije (Mr) mogu se objasniti dvostrukom domenskom strukturom karakterističnom za ovakve uzorke. Analiza mjerenja pokazuje da su unutrašnje domene odgovorne za magnetizaciju do 65% magnetizacije zasićenja (Ms) te da interakcija između dviju domenskih struktura igra važnu ulogu pri ubrzanom rastu Hc pri Mm > 0.5 Ms. Razmatrana je i ovisnost parametara krivulje histereze o frekvenciji

An improvement of automatic modulation classification based on sixth-order cumulant for QAM signals

Automatska klasifikacija modulacija (AKM) predstavlja proces prepoznavanja tipa modulacije nepoznatog primljenog signala, veoma bitan za savremene telekomunikacione sisteme, i ključan za veliki broj kako vojnih tako i civilnih primena. U poslednjih nekoliko decenija razvijen je veliki broj različitih algoritama za AKM. Savremena rešenja uobičajeno pretpostavljaju kompleksne strukture kao što su neuralne mreže, ili druge adaptivne mehanizme za postizanje bolje preciznosti. Međutim, još uvek je, sa tačke gledišta implementacije u praksi, veoma poželjno da se za AKM koriste algoritmi male kompleksnosti koji se brzo izvršavaju i koji ekonomično koriste resurse. Ove poželjne osobine mogu se prepoznati u algoritmima za AKM zasnovanim na kumulantima višeg reda kao statističkim klasifikacionim obeležjima. U ovoj disertaciji je prikazan novi pristup zasnovan na kumulantima šestog reda, koji poboljšava tačnost klasifikacionog procesa QAM signala u odnosu na postojeće algoritme. Predloženi pristup koristi dvokoračnu strukturu za izdvajanje obeležja, tako što primenjuje nov metod za redukciju reda modulacije opserviranog signala, praćen pragovskim odlučivanjem. Predložen je i odgovarajući rekurzivni algoritam, usmeren ka uspešnoj klasifikaciji signala visokog reda modulacije. Prilikom testiranja pomoću sveobuhvatnih računarskih simulacija, predložena rešenja pokazuju izvanredne performanse klasifikacije ‑ u nekim slučajevima bolje i od sofisticiranih modela dubokog učenja koji zahtevaju znatno veće procesorske i memorijske resurse; takođe, predloženi metod zadržava dobre statističke osobine kumulanata, tako da se može primeniti udružen i sa drugim algoritmima za AKM. Pokazane prednosti predloženih rešenja otvaraju nekoliko smerova za dalja istraživanja, bilo kroz dalje usavršavanje algoritama zasnovanih na obeležjima, ili kroz uparivanje sa savremenim metodama koje koriste veće računarske resurse

Clonal persistence of Salmonella enterica serovars Montevideo, Tennessee, and Infantis in feed factories

Introduction: Novel molecular techniques applied in biotechnology research have provided sound evidence on clonal persistence of distinct serovars of Salmonella in feed factory environments, over long periods of time (months, even years), which can be responsible for repeated in-house contamination of final products. In this study, we examined the possibility of clonal persistence of isolates of three Salmonella serovars that have been repeatedly identified in animal feed samples from three feed factories throughout a two-year period. Methodology: The isolates Salmonella enterica serovars Tennessee (n = 7), Montevideo (n = 8), and Infantis (n = 4) were tested for genetic diversity using pulsed-field gel electrophoresis (PFGE) and multicellular behavior patterns by applying the Congo red agar test. Results: SpeI and XbaI macro-restriction profiles indicated that isolates S. Montevideo and S. Infantis were identical, whereas isolates of S. Tennessee demonstrated greater genetic diversity, although the genetic differences did not exceed 10%. All Salmonella serovars demonstrated the ability to produce predominant matrix compounds essential for biofilm formation, curli fimbriae and cellulose. Conclusions: The identification of identical clones of S. Montevideo and S. Infantis, as well as the minor genetic diversity of S. Tennessee, which have been repeatedly isolated from animal feed in three production plants throughout a two-year period, indirectly suggests the possibility of their persistence in feed factory environments. Their ability to express the key biofilm matrix components further supports this hypothesis

Maligni tumori kod Labrador retrivera koji se koriste za pronalaženje narkotika

The two corpses of police dogs, of Labrador retriever breed used for fi nding narcotics, were sent to the Scientific Veterinary Institute 'Novi Sad', and examined post-mortem, in order to determine the cause of death. Post-mortem examination revealed the presence of neoplastic changes in the mandibular region, pulmonary parenchyma and axillary region. The samples of neoplastic changes were sent to the Laboratory of Patohistology within the Faculty of Veterinary Medicine, University of Belgrade, in order to specify the diagnosis. Histopathology examination revealed an adenocarcinoma in lungs and haemangioendothelioma in axillary region. Is there any role of drug sniffing on the occurrence of neoplasia in Labrador retriever breed is still unknown, but it could be an important factor in the development of neoplasia in these dogs.Dva leša policijskih službenih pasa, rase Labrador retriver koji se koriste za pronalaženje narkotika, dostavljeni su u Naučni institut za veterinarstvo 'Novi Sad', kako bi se na osnovu patomorfološkog pregleda utvrdio uzrok smrti. Tokom obdukcije utvrđeno je prisustvo neoplastičnih promena u mandibularnoj regiji, plućnom parenhimu i aksilarnoj regiji. Uzorci promenjenog tkiva dostavljeni su na Fakultet veterinarske medicine, Univerziteta u Beogradu, u laboratoriju za patohistologiju kako bi se odredila tačna dijagnoza. Patohistološkim nalazom utvrđeno je prisustvo adenokarcinoma u plućima i hemangioendotelioma u predelu aksilarne regije. Kakvu ulogu može imati udisanje narkotika na pojavu neoplazmi kod Labrador retrivera još uvek nije poznato, ali se pretpostavlja da to može biti jedan od faktora u nastanku neoplastičnih promena kod ovih službenih pasa

Essential Oils as Feed AdditivesFuture Perspectives

The inconsistency of phytogenic feed additives' (PFA) effects on the livestock industry poses a risk for their use as a replacement for antibiotic growth promoters. The livestock market is being encouraged to use natural growth promotors, but information is limited about the PFA mode of action. The aim of this paper is to present the complexity of compounds present in essential oils (EOs) and factors that influence biological effects of PFA. In this paper, we highlight various controls and optimization parameters that influence the processes for the standardization of these products. The chemical composition of EOs depends on plant genetics, growth conditions, development stage at harvest, and processes of extracting active compounds. Their biological effects are further influenced by the interaction of phytochemicals and their bioavailability in the gastrointestinal tract of animals. PFA effects on animal health and production are also complex due to various EO antibiotic, antioxidant, anti-quorum sensing, anti-inflammatory, and digestive fluids stimulating activities. Research must focus on reliable methods to identify and control the quality and effects of EOs. In this study, we focused on available microencapsulation techniques of EOs to increase the bioavailability of active compounds, as well as their application in the animal feed additive industry

Mikrobiološka kontaminacija prostirke tokom tova brojlera

The results of the research into the microbiological contamination of litter used by broiler chickens are presented. Litter samples were taken prior to the introduction of chicks (day 0) and in 7-day intervals until the end of the fattening period. The total numbers of aerobic mesophilic microorganisms, yeasts, moulds and Clostridium perfringens spores, and the presence of bacteria of the Salmonella genus were determined. The total microbial count in newly laid litter was 7 log10 CFU/g, which increased to 9 log10 CFU/g by the 4th week. However, at the end of the 5th week, it was at the same level as in newly laid litter. C. perfringens spores, presumably originating from chicks' faeces, were first detected on day 7. In the next 7 days their number increased, reaching 3-4 log10 CFU/g, and remained at approximately same levels until the end of the research. The initial mould contamination was 5-6 log10 CFU/g. However, from day 21 moulds were not isolated, but only yeasts of the Saccharomyces genus. It is supposed that these were deposited with chicks' faeces, due to their presence in complete broiler feed. No bacteria of the Salmonella genus were ever isolated from the litter. In conclusion, the total numbers of microorganisms in deep litter reach their peak in approximately a month, which is followed by their decrease. Deep litter is a favourable environment for probiotic yeast cultures. Added to feed intended for broilers, they can positively influence the microbial composition of litter, providing healthier environment to fattening broilers.U radu su prikazani rezultati ispitivanja mikrobiološke kontaminacije prostirke korišćene u tovu pilića. Prostirka je uzorkovana pre naseljavanja objekata i u nedeljnim intervalima tokom 35 dana tova pilića. Uzorci su ispitani na ukupan broj aerobnih mezofilnih mikroorganizama, kvasaca, plesni i spora Clostridium perfringens, kao i prisustvo bakterija roda Salmonella. Ukupan broj mikroorganizama u svežoj prostirci iznosio je 7 log10 CFU/g, a do 4 nedelje tova pilića povećao se do 9 log10 CFU/g. Međutim, na kraju pete nedelje tova, ukupan broj mikroorganizama u prostirci bio je na nivou vrednosti ustanovljenih u svežoj prostirci. Spore C. perfringens su ustanovljene tek sedmog dana od naseljavanja objekta, što ukazuje da u prostirku dospevaju fecesom pilića. Za 14 dana broj spora C. perfringens se povećao do 3-4 log10 CFU/g i na približno istim vrednostima zadržao do kraja ispitivanja. Sveža prostirka bila je kontaminirana plesnima u nivou od 5-6 log10 CFU/g, ali od 21. dana iz uzoraka prostirke nisu izolovane plesni, već samo kvasci roda Saccharomyces. Pretpostavka je da su kvasci u prostirku dospeli fecesom pilića, jer se koriste kao probiotske kulture u smešama za njihov tov. Bakterije roda Salmonella nisu izolovane iz prostirke. Rezultati ispitivanja pokazuju da ukupan broj mikroorganizama u prostirci dostiže svoj pik za oko mesec dana, nakon čega se smanjuje. Prostirka je pogodna sredina za život probiotskih kultura kvasaca i njihovo dodavanje u smeše za tov brojlera može imati povoljan uticaj na sastav mikroorganizama u prostirci, a time i obezbeđenje zdravije životne sredine u podnom sistemu uzgoja brojlera

Epizootiološki značaj Salmonella spp. izolovanih u različitim vidovima živinarske proizvodnje u Južnobačkom i Sremskom okrugu

Salmonella causes local and systemic infections of poultry, which may lead to substantial direct and indirect economic losses, presenting also significant risk to human health. The aim of this study was to monitor the occurrence of certain serotypes of Salmonella spp. isolated on poultry farms in Southern Bačka and Srem regions in the period from 2010 to 2014, as recommended by the Book of rules of early detection, diagnostic, prevention of spreading and eradication of Salmonella spp. We analyzed the results obtained from the laboratory for clinical bacteriology to determine number of salmonella cases. From all samples that have been submitted for bacteriology analysis, salmonellas were isolated from 7.3% samples. Salmonella infantis was isolated from 50.3% of all salmonella-positive samples, mostly from materials supplied from broiler farms. Salmonella enteritidis was most frequently isolated in broiler chickens at the rate of 48.2%. There is an increasing trend in the occurrence of Salmonella enteritidis and Salmonella infantis on poultry farms from year to year. Our research revealed the highest incidence of salmonella isolates in broilers that died during transportation or within the first three days upon arrival of chickens. During the five-year research period, 65 samples from parent flocks (63 from broiler breeders and 2 from parent flocks of layers) were salmonella positive, which makes 8.03% of all positive isolates. It is most likely that salmonella infection occurs due to infection of parent flocks and young chickens are infected trough both vertical and horizontal transmission. .Salmonele kod živine izazivaju infekcije lokalnog i sistemskog karaktera, dovodeći do značajnih kako direktnih tako i indirektnih ekonomskih gubitaka u industrijskom živinarstvu i predstavljaju opasnost po zdravlje ljudi. Cilj ovog rada bio je monitoring određenih sojeva Salmonella spp. propisanih Pravilnikom o utvrđivanju mera za rano otkrivanje, dijagnostiku, sprečavanje širenja, suzbijanje i iskorenjivanje infekcija živine određenim serotipovima salmonella, na teritoriji Sremskog i Južnobačkog okruga u periodu od 2010. do 2014. godine. Analizirali smo rezultate ispitivanja laboratorije za kliničku bakteriologiju. Od ukupno ispitanih bakterijskih infekcija iz kliničkog materijala u ovom petogodišnjem periodu, salmonele su izolovane u 7,3% slučajeva. Ustanovljeno je da je Salmonella infantis izolovana u 50,3% svih pozitivnih uzoraka, najčešće iz materijala dostavljenih sa farmi brojlerskih pilića. Salmonella enteritidis izolovana je u 48,2%, takođe najčešće kod brojlerskih pilića. Prisutan je trend porasta izolata Salmonella enteritidis i Salmonella infantis iz godine u godinu. Našim istraživanjem ustanovili smo da je najviše pozitivnih uzoraka bilo kod brojlera, u transportnim uginućima i uginućima iz prva tri dana starosti. Kod roditeljskih jata bilo je pozitivno 65 uzoraka u ovom petogodišnjem periodu (63 kod teške linije i 2 kod lake linije), što iznosi 8,03 % od svih pozitivnih izolata. Pretpostavlja se da je do infekcije salmonelama moglo doći usled horizontalne i vertikalne infekcije preko roditeljskih jata.

Comparative pathological findings in mute swans (Cygnus olor) naturally infected with highly pathogenic Avian influenza viruses H5N1 and H5N8 in Serbia

The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 Glade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8