Polaganje podmorskih cjevovoda u obalnom području

Hidrodinamičko opterećenje valova i morske struje te savijanje uslijed zakrivljenosti morskog dna dva su bitna problema kojima u projektu podmorskih cjevovoda za transport nafte i plina treba posvetiti nužnu pažnju u obalnom području. U članku je opisan metodološki postupak dimenzioniranja i provjere stabilnosti čeličnog, betonom obloženog podmorskog cjevovoda, slobodno položenog na zakrivljeno morsko dno. Ravnotežni položaj savinutog cjevovoda koji je izložen radnom, gravitacijskom i hidrodinamičkom opterećenju, određen je na nelinearnom strukturnom modelu konačnih elemenata. Model uključuje geometrijsku nelinearnost uslijed velikih pomaka i nelinearnost uslijed kontaktnog problem između cjevovoda i morskog dna. Ilustrativnim primjerom prikazan je način definiranja projektnog stanja mora i dana je usporedba bitnih rezultata dobivenih vremenskom simulacijom s rezultatima važećih propisa

An Improved Stiffness Model for Polyester Mooring Lines

The stiffness model of highly extensible polyester mooring lines is studied. Mooring lines are considered within coupled dynamic model of a moored fl oating object. In more detail, deepwater mooring with taut polyester mooring lines is observed. In this case mooring line is modelled as an extensible cable without bending and torsional stiffness. Movements are assumed to be three-dimensional, so it is necessary to examine large displacement model. In longitudinal strain calculation the material of the mooring line is considered as nonlinear. A large elongation value is examined within the stiffness model. Inertial forces of the mooring line are also considered. Hydrodynamic loads due to surrounding fl uid are taken into account with the Morison equation. Due to nonlinear properties of mooring lines calculations have to be done in time domain. On these assumptions, derivation of a mooring line fi nite element is presented for static and dynamic analysis. A fl oating object is modelled as a rigid body with six degrees of freedom and with small displacements assumption. Hydrodynamic coeffi cients are calculated in a specifi ed frequency domain; therefore, mapping from the frequency to the time domain is necessary. Comparison between the improved model developed in this paper and current equivalent model is done. A simple mooring line that can be analytically described was the base for comparison. The improved model achieved better agreement with the analytical result

Pregled gamma funkcija kod akumuliranog proračuna zamora brodskih konstrukcija

Palmgren-Miner (P-M) pristup je najstarija, najjednostavnija i najčešće korištena metoda za proračun zamornog oštećenja brodskih konstrukcija. Pod pretpostavkom Weibullove distribucije raspona naprezanja, klasifikacijska društva su usvojila P-M analitičke izraze za proračun akumuliranog oštećenja. U upotrebi postoji više verzija sličnih izraza te svaki od njih uključuje neki oblik Gamma funkcija. Stoga, točna procjena Gamma funkcija predstavlja jedan od ključnih parametara za pouzdan proračun zamornog oštećenja. Primijećeno je da pravila za proračun zamora kod brodskih konstrukcija ne posvećuju dovoljno pažnje preciznoj definiciji Gamma funkcija, uzrokujući tako gubitak vremena i eventualne greške u proračunu. Ovaj članak predstavlja pregled izraza za proračun akumuliranog oštećenja važnijih klasifikacijskih društava, nastojeći rasvijetliti kako i koji tip Gamma funkcije efikasno odrediti

Methods of detection and typing of methicillin resistant Staphylococcus aureus isolated from animals

In this work there was evaluated the method of detection of methicillin resistant Staphylococcus aureus (MRSA) by using two molecular and three phenotypic tests in investigation procedure of 70 strains of S.aureus isolated from animals. Recent findings of the new mecA homologue, mecALGA251, minimise the significance of mecA gene presence detection as a confirmation method of methicillin resistant Staphylococcus aureus identification. For this reason, along with multiplex PCR set of primers(165rDNK, nuc, mecA) for detection mecA gene, there was also used multiplex PCR set of primers (spa, mecA, pvl, mecALGA251) for differentiation mecALGA251 from mecA, with simultaneous detection of luk-PV and spa gene fragments. In all 70 investigated isolates there was detected the presence of specific 16 SrDNK fragment and nuc gene which encodes a thermostable S. aureus nuclease, while in 5 out of 70 S. aureus isolates, there was proven mecA gene presence using two multiplex PCR tests. In the investigated strains there was determined neither mecC (mecALGA251)gene presence, nor Panton Valentine Leukocidin encoding gene. By application cefoxitin disk-diffusion, latex-agglutination and two multiplex PCR tests, the identical results in identification 5 methicillin resistant out of 70 investigated S. aureus strains were obtained. In our investigation there was determined a complete correlation between the results of phenotypic and genotypic identification of methicillin resistant S. aureus. [Projekat Ministarstva nauke Republike Srbije, br. TR 31079

Comparative pathomorphological, mycological and molecular examination of turkey poults with different immunological status experimentally infected with aspergillus fumigatus

The aim of this study was to determine the pathological, mycological and molecular findings in turkey poults with different immunological status experimentally infected with Aspergillus fumigatus. The investigation was carried out 1, 3, 7, 14 and 21 days after intratracheal inoculation of 5.056x10(7) spores of A. fumigatus to 14-day-old turkey poults in group G-1, as well as to turkey poults in group G-2 which were treated prior to infection with dexamethasone. A. fumigatus was isolated on day 1 p.i. in both groups, but the number of positive samples was bigger in group G-1. A. fumigatus was isolated from the respiratory organs of group G-1as early as on day 1 and 3 p.i. in 4 out of 12 examined specimens (33%). On day 7 p.i. A. fumigatus was possible to isolate from the respiratory organs of 50% of infected birds, on day 14 in 83.33% and on day 21 p.i. A. fumigatus was isolated in 6 out of 6 sacrificed turkey poults (100%). In dexamethasone-treated group A. fumigatus isolates from the respiratory organs on day 1 and 3 p.i. were same as in group G-1, whereas on days 7 and 14 p.i. the number of turkey poults positive to A. fumigatus increased in comparison with the untreated G-1 group. The histopathological lesions in turkey poults treated with dexamethasone developed earlier, were more intensive and extensive. The mycological and nested PCR results revealed a higher number of samples positive for the presence of A. fumigatus DNA in the group G-2, pretreated with dexamethasone

Psychoneurotic disorders and behavioural disturbances in primary school children whose parents are employed abroad

Svrha ispitivanja je da se utvrdi postoji li veća učestalost psihoneurotičnih poremećaja i poremećaja ponašanja u djece koja žive odvojeno od roditelja zbog njihova rada u inozemstvu, u odnosu na njihove vršnjake. Obrađeno je 26 djece, uzrasta od 6—15 godina, čiji su roditelji u inozemstvu, i 26 djece kontrolne grupe istog uzrasta, koja žive sa roditeljima. Prisutnost psihoneurotičnih poremećaja zastupljena je u visokom postotku u obje grupe: u eksperimentalnoj sa 76,92%, a u kontrolnoj sa 61,54%. Statistički je značajna psihološkom obradom utvrđena razlika učestalosti ispoljavanja neurotič­ nih reakcija eksperimentalne (53,85%) i kontrolne grupe (26,92%). Značajne razlike utvrđene su u učestalosti ispoljavanja osjećaja odbačenosti između eksperimentalne grupe (53,85%) i kontrolne grupe (11,54%). Razlika je također u intelektualnoj nezrelosti eksperimentalne grupe (38,46%) u odnosu na kontrolnu (0%), kao i u učestalosti poremećaja ponašanja eksperimentalne grupe (61,54%) u odnosu na kontrolnu (23,08%). Sve to ukazuje na povećanu psihičku vulnerabilnost djece koja žive u nekompletnom porodičnom sastavu. Relativno visok postotak poremećaja u kontrolnoj grupi povlači pitanje kvaliteta odnosa unutar kompletnih porodica i njihov utjecaj na formiranje psihoneuroza razvojnog doba.The purpose of this study was to determine whether psychoneurotic disorders and behavioural disturbances are more frequent in schoolchildren whose parents work abroad than in their peers living with their parents. We examined 26 children aged 6 to 15 years, whose parents work abroad and 26 children of the same age who live with their parents. Both groups of children attended »B. Maslarić« primary school in Borovo. Psychoneurotic disorders were frequent in both groups of schoolchildren. They were found in 76.92% of children in the experimental group and in 61.54% of children in the control group. Psychological treatment revealed statistically significant differences in the frequency of neurotic reactions between the experimental group (53.85%) and the control group (26.92%). The differences between the experimental and control groups in the manifestations of the feeling of rejection, intellectual immaturity and the frequency of behavioural disturbances were highly significant. The respective proportions of these disorders were: 53.85%, 38.46% and 61.54% in the experimental group as compared to 11.54%, 0.0% and 23.08% in the control group. These facts show that children living in incomplete families are psychologically more vulnerable than their peers. The relatively high frequency of disorders in the control group raises the question of the nature of relationships in complete families and of their influence on the development of childhood psychoneuroses

Psychoneurotic disorders and behavioural disturbances in primary school children whose parents are employed abroad

Svrha ispitivanja je da se utvrdi postoji li veća učestalost psihoneurotičnih poremećaja i poremećaja ponašanja u djece koja žive odvojeno od roditelja zbog njihova rada u inozemstvu, u odnosu na njihove vršnjake. Obrađeno je 26 djece, uzrasta od 6—15 godina, čiji su roditelji u inozemstvu, i 26 djece kontrolne grupe istog uzrasta, koja žive sa roditeljima. Prisutnost psihoneurotičnih poremećaja zastupljena je u visokom postotku u obje grupe: u eksperimentalnoj sa 76,92%, a u kontrolnoj sa 61,54%. Statistički je značajna psihološkom obradom utvrđena razlika učestalosti ispoljavanja neurotič­ nih reakcija eksperimentalne (53,85%) i kontrolne grupe (26,92%). Značajne razlike utvrđene su u učestalosti ispoljavanja osjećaja odbačenosti između eksperimentalne grupe (53,85%) i kontrolne grupe (11,54%). Razlika je također u intelektualnoj nezrelosti eksperimentalne grupe (38,46%) u odnosu na kontrolnu (0%), kao i u učestalosti poremećaja ponašanja eksperimentalne grupe (61,54%) u odnosu na kontrolnu (23,08%). Sve to ukazuje na povećanu psihičku vulnerabilnost djece koja žive u nekompletnom porodičnom sastavu. Relativno visok postotak poremećaja u kontrolnoj grupi povlači pitanje kvaliteta odnosa unutar kompletnih porodica i njihov utjecaj na formiranje psihoneuroza razvojnog doba.The purpose of this study was to determine whether psychoneurotic disorders and behavioural disturbances are more frequent in schoolchildren whose parents work abroad than in their peers living with their parents. We examined 26 children aged 6 to 15 years, whose parents work abroad and 26 children of the same age who live with their parents. Both groups of children attended »B. Maslarić« primary school in Borovo. Psychoneurotic disorders were frequent in both groups of schoolchildren. They were found in 76.92% of children in the experimental group and in 61.54% of children in the control group. Psychological treatment revealed statistically significant differences in the frequency of neurotic reactions between the experimental group (53.85%) and the control group (26.92%). The differences between the experimental and control groups in the manifestations of the feeling of rejection, intellectual immaturity and the frequency of behavioural disturbances were highly significant. The respective proportions of these disorders were: 53.85%, 38.46% and 61.54% in the experimental group as compared to 11.54%, 0.0% and 23.08% in the control group. These facts show that children living in incomplete families are psychologically more vulnerable than their peers. The relatively high frequency of disorders in the control group raises the question of the nature of relationships in complete families and of their influence on the development of childhood psychoneuroses

Dinamika broda u teglju

Tegljenje kao specifična vrsta pomorskog prijevoza često se koristi za instaliranje objekata za bušenje i eksploataciju podvodnih plinskih i naftnih bušotina. Za potrebe ovog istraživanja, razmatra se brod tegljen na valovima u pramac. Jedan kraj linije za tegljenje spojen je s pramcem broda, a drugi se giba pravocrtno konstantnom brzinom. Razmatranja se provode u vertikalnoj ravnini, tako da je brod modeliran kao kruto tijelo s tri stupnja slobode gibanja. Uzbune sile uslijed valova uzete su u obzir, zajedno s dodanom masom i radijacijskim prigušenjem. Za procjenu sile u užetu za tegljenje koristi se pojednostavljeni pristup. Ovaj pristup uzima u obzir aksijalnu i geometrijsku krutost užeta za tegljenje, bez inercijskih sila i prigušenja. Zbog nelinearnih svojstava problema, proračuni su provedeni u vremenskoj domeni. Dobiveni numerički rezultati uspoređeni su s objavljenim eksperimentalnim rezultatima

Root xylem anatomy of the wild and cultivated sunflower

The root functionality is affected by numerous factors. One of the main structural parameters, the most important for functionality and adaptability, is xylem organization. Taking into account that sunflower root features have not been directly selected in breeding programs the aim of this research is to determine whether different sunflower genotypes (wild annual species and cultivated genotypes) have influence (i) on the structure of the xylem anatomy and (ii) on the xylem features along the maturity gradient. For the detailed anatomical characterization of root xylem, 14 days old seedlings which were grown in rhizotrons, have been carried out on the primary root. Root cross-sections were cut in positions sampled according to the principle of systematic uniform random sampling method. Along the root maturity, three sections per roots were made using cryotechnic procedure. Observations of the root and measurements of the vessels were carried out using the light microscope with Image Analyzing System. The obtained results of the comparative root xylem anatomy revealed significant phenotypic variability among tested genotypes. The ratio of cross-section xylem area, vessel diameter and theoretical hydraulic conductance (kh), increase along the maturity gradient for all genotypes. Significant differences in vessel size and frequency were recorded between wild species and cultivated genotypes