Tehnologije polaganja podmorskih cjevovoda u priobalnom području

Nafta je znana ljudima već više od 5000 godina te je korištena prvenstveno kao mast ili kao lijek, ali ne kao gorivo. U Bibliji se spominje korištenje katrana u svrhu cementiranja zidova u Babilonu. Prvi izvor zemnog plina probušen je 1820 godine u Fredonii, NY, USA, na dubini od 10 metara. Prva je plinska lampa bila postavljena na gradsku vjećnicu. Uvidjevši prednosti građani toga grada više nisu htjeli biti u mraku i izgradili su cijelu infrastrukturu i osvjetlili Fredoniu plinskim lampama putem olovnih cijevi. Nedugo zatim svi su veći gradovi u SADu imali uličnu rasvjetu. Prvi je moderni, bušeni izvor nafte nastao u Poljskoj 1854. godine od strane Poljskog apotekara Ignacyja Lukasiewicza. Na to ga je nagnala potreba za čistim kerozinom. Naime, do tada se kerozin dobivao iz skupog kitovog ulja. Kako je vrijeme prolazilo, naftaši su uočili da što su bliže obali, to su nalazišta bila bogatija. H.L. Williams je došao 1887. godine na ideju da sagradi gat te na njega stavi opremu za bušenje. U prvim bušenjima udaljenost od obale je bila 90 metara, dok se najdulji gat protezao do dužine od 400 metara. Zbog tehnološke revolucije, potreba za ugljikovodicima je rasla pa je tako i ideja o širenju industrije na more imala sve više smisla. Tako je 1947.g. sagrađena prva offshore platforma pod Kerr-McCgee korporacijom te je taj događaj označio novu eru u naftnoj industriji. Do 1949.g. u Meksičkom zaljevu je nađeno 11 rezervoara nafte i zemnog plina sa 44 istraživačke bušotine. Osnovne namjene podmorskih cjevovoda su: - transport ugljikohidrata (nafta i plinovi) - transport vode - transport ispusta u priobalnom područj

Robust Stability of Singularly Impulsive Dynamical Systems

In this paper, we present results of the robust stability analysis for the class of nonlinear uncertain singularly impulsive dynamical systems. We present sufficient conditions for the robust stability of a class of nonlinear uncertain singularly impulsive dynamical systems. The problem of evaluating performance bounds for a nonlinear-nonquadratic hybrid cost functional depending upon a class of nonlinear uncertain singularly impulsive dynamical systems is considered. It turns out that the cost bound can be evaluated in closed form as long as the hybrid cost functional is related in a specific way to an underlying Lyapunov function that guarantees robust stability over a prescribed uncertainty set. Then, results for the case of uncertain singularly impulsive dynamical systems are presented. The results obtained for the nonlinear case are further specialized to linear singularly impulsive dynamical systems

137Cs activity concentrations in mussels Mytilus galloprovincialis from the Northen Adriatic Sea

Neposredni izvor radionuklida u Jadranskom moru je atmosfersko zagađivanje (fallout), pogotovo nakon Černobilske nesreće 1986. godine, a posredni izvori su donosi rijekama. Program praćenja radioaktivnosti u morskim indikatorskim organizmima se temelji na praćenju koncentracije aktivnosti radionuklida 137Cs, 40K, 232Th (228Ra), 226Ra, 238U i 7Be u tkivu dagnji Mytilus galloprovincialis. Dagnje su uzorkovane u travnju i listopadu od 2008. do 2014. godine na postajama u Limskom kanalu, Raškom i Bakarskom zaljev. Sve postaje istraživanja su veliki zaljevi pod izrazitim utjecajem dotoka slatkih voda, što se vidi iz vrijednosti saliniteta koji su ispod prosjeka za sjeverni Jadran, a naročito u Bakarskom zaljevu. U Limskom kanalu koncentracije aktivnosti umjetnog radionuklida 137Cs u dagnji su bile ispod granica detekcije (<0,3 Bq kg-1 suhe mase tkiva), što je povezano s niskom koncentracijskom aktivnosti 137Cs u morskoj vodi (1.83 Bq m-3). Na svim postajama koncentracije aktivnosti 137Cs u dagnji su se kretale ispod granica detekcije, izuzev četiri puta u Trgetu i u Bakru. Utjecaj dotoka slatke vode na svim postajama dokazuju povećane koncentracije aktivnosti 7Be u dagnji tijekom proljeća u odnosu na jesen. Obrnuto koncentracije aktivnosti 40K u dagnji su više u jesenskom dijelu godine u odnosu na proljetni. Koncentracije aktivnosti prirodnih radionuklida 232Th (228Ra), 238U i 226Ra u tkivima dagnji su izrazito niske i bitno se sezonski ne razlikuju na svim postajama. Povišene koncentracije aktivnosti pojedinih radionuklida u tkivu dagnji dokazuju iznimnu sposobnost filtracije morske vode i indikatorski potencijal ovih organizama. Radioekološko stanje sjevernog Jadrana je zadovoljavajuće i nema značajnijeg unosa radionuklida falloutom i donosom rijekamaThe source of radionuclides in the Adriatic Sea is global fallout primarily from the Chernobyl accident in 1986 and indirectly from the rivers discharges. A monitoring program for radioactivity in the northern Adriatic Sea was conducted by determination 137Cs, 40K, 232Th (228Ra), 226Ra, 238U and 7Be in the tissues of mussels Mytilus galloprovincialis, in spring and autumn periods from 2008 to 2014. A comparison of radioactive contamination was made between three locations of the northern Adriatic Sea (Lim Bay, Raša bay and Bakar bay) under significant fresh water discharges. These are evident from the salinitys which were below average for the northern Adriatic Sea, especially in the Bakar bay. In Lim Bay 137Cs activity concentrations in surface seawater were low (1.83 Bq m-3). In mussels 137Cs activity concentrations (< 0.3 Bq kg-1 dry weight) were below the detection limit in all locations, except four times in Trget and Bakar. The impact of the fresh water influx at all locations proves increased activity concentration of 7Be in mussels during the spring compared to autumn. Conversely the activity concentrations of 40K in mussels were higher in autumn compared to spring. Activity concentrations of primordial radionuclides 232Th (228Ra), 238U and 226Ra in mussels were mostly below the detection limit with no seasonal changes. Increased activity concentrations of individual radionuclides in the mussel tissues proved the exceptional ability of seawater filtration and indicator potential of these organisms. Radioecological condition of the northern Adriatic is satisfactory and there are not significant intake of radionuclides from fallout and the rivers discharge

Prebrajanje razapinjućih stabala grafa

Ovaj se članak bavi tehnikama za prebrojavanje razapinjućih stabala grafa. Predstavljen je Kirchoffov matrični teorem o stablima koji povezuje broj razapinjućih stabala grafa i determinantu matrice čije vrijednosti ovise o grafu. Primjenom teorema izračunat je broj razapinjućih stabala od potpunog grafa Kn, potpunog bipartitnog grafa Krs i grafa kotača Wn

SINGULARLY IMPULSIVE DYNAMICAL SYSTEMS WITH TIME DELAY: MATHEMATICAL MODEL AND STABILITY

In this paper we introduce a new class of systems, the so-called singularly impulsive or generalized impulsive dynamical systems with time delay. Dynamics of these systems is characterized by a set of differential and difference equations with time delay, and by algebraic equations. They represent a class of hybrid systems where algebraic equations represent constraints that differential and difference equations with time delay need to satisfy. In this paper we present a model, assumptions about the model, and two classes of singularly impulsive dynamical systems with delay – time-dependent and state-dependent. Further, we present the Lyapunov and asymptotic stability theorems for nonlinear time-dependent and state-dependent singularly impulsive dynamical systems with time delay

Protection of Karst Springs Used for Water Supply in Istria by Building Sewage Systems for Small Rural Settlements

Odvodnja otpadnih voda u Republici Hrvatskoj s ukupno 6.762 naselja grupirana je u 736 aglomeracija, od čega 468 aglomeracija ima opterećenje do 2.000 ekvivalent stanovnika (ES). Iako se zahtjevi Direktive o pročišćavanju komunalnih otpadnih voda odnose provenstveno na aglomeracije veće od 2.000 ES, neophodno je adekvatno zbrinjavati otpadne vode i manjih aglomeracija, pogotovo u osjetljivim područjima kao što su zone sanitarne zaštite izvorišta vode za piće. U cilju zaštite izvorišta vode u Istarskoj županiji izrađena je studija „Organizacija, izgradnja i održavanje sustava odvodnje i pročišćavanja otpadnih voda za mala naselja u obuhvatu vodozaštitnih područja u Istarskoj županiji" te je osnovano trgovačko društvo IVS – Istarski vodozaštitni sustav d.o.o., koje je u vlasništvu svih gradova i općina Istarske županije čiji je zadatak realizacija navedene Studije. Studija obuhvaća 173 naselja u zonama sanitarne zaštite izvorišta vode za piće na području Istre, u kojima živi oko 38.000 stanovnika. U ovom radu će se prikazati rješenja dvaju sustava odvodnje otpadnih voda za mala naselja u Istri koja su izrađena u okviru dvaju diplomskih radova: sustav za naselje Loborika i sustav za naselja Rapavel, Anžići i Smolići. Cilj rada je istaknuti problematiku zaštite izvorišta vode za piće u kršu, mogućnosti zaštite izvorišta izgradnjom odgovarajućih sustava odvodnje i uređaja za pročišćavanje otpadnih voda, probleme koji se javljaju pri projektiranju razdjelnih sustava odvodnje otpadnih voda za aglomeracije manje od 2.000 ES kao i probleme koji se mogu očekivati u budućnosti pri korištenju sustava.Wastewater drainage for 6.762 settlements in the Republic of Croatia is grouped in 736 agglomerations, of which 468 agglomerations have loads of up to 2.000 population eqivalent (PE). Although the requirements of the Urban Wastewater Treatment Directive apply to agglomerations of more than 2.000 PE, it is necessary to adequately dispose wastewater of these smaller agglomerations, particularly in sensitive areas such as drinking water protection zones. In order to protect drinking water sources in the Istrian County, the study "Organization, construction and maintenance of drainage and wastewater treatment systems for small settlements in drinking water protection areas of the Istrian County" was prepared and the Istrian Water Protection System Ltd., whose task is the realization of the above mentioned Study, was established. The Study included 173 settlements in the areas of drinking water protection zones, where about 38.000 inhabitants live. This paper presents the designs of two wastewater drainage systems for small settlements in Istria, which were developed within two graduation theses: for the settlement Loborika and for settlements Rapavel, Anžići and Smolići. The aim of this paper is to highlight the problem of drinking water sources protection in karst areas, the possibility of protection by construction of appropriate sewage systems and wastewater treatment plants, problems encountered in the design of separate systems for agglomerations less than 2.000 PE as well as problems that can be expected in the future when these systems will be in use

THE EFFECT OF INTRADIALYTIC EXERCISE PROGRAM ON THE QUALITY OF LIFE AND PHYSICAL PERFORMANCE IN HEMODIALYSIS PATIENTS

Cilj rada bio je istražiti učinak 16-tjednog intradijaliznog programa vježbanja, koji se sastoji od 30 minuta vježbanja u toku prva 2 sata dijalize sa učestalošću od 3 puta sedmično, na kvalitetu života, razinu depresije i anksioznosti, te na fizičke performanse pacijenata na hemodijaliznom (HD) tretmanu. Provedena je klinička, longitudinalna, prospektivna studija s dizajnom ponovljenih mjerenja u trajanju od 16 tjedana. U istraživanje je uključen namjerni uzorak od 52 HD pacijenta, koji su na HD tretmanu najmanje 6 mjeseci. Na početku i nakon 16 tjedana programa vježbanja izmjereni su kvaliteta života, stupanj depresije i anksioznosti (anketni upitnici: SF-36, Back Depression Inventory-BDI i Back Anxiety Inventory-BAI) te fizičke performanse (modificirana vizualna analogna ljestvica za subjektivnu procjenu fizičke kondicije-VAS i manualni mišićni test-MMT). Nakon 16-tjednog programa vježbanja značajno su bile poboljšane sljedeće ljestvice anketnog upitnika SF-36: uloga funkcioniranja/emocionalno (P=0,018), energija/zamor (P=0,002) i socijalno funkcioniranje (P = 0,030). Razine depresije i anksioznosti bile su značajno snižene u muškaraca (P = 0,007 i P = 0,022 i žena (P = 0,001 i P = 0,000). Ljestvice VAS i MMT imale su značajno više vrijednosti u muškaraca (P = 0,000 i P = 0,001) i žena (P = 0,019 i P = 0,001). Zaključujemo da intradijalizni program vježbanja vjerojatno dovodi do poboljšanja pojedinih aspekata kvalitete života i fizičkih performansi te sniženja razine depresije i anksioznosti u HD pacijenata.Aim: To determine the effect of a 16-week intradialytic exercise program consisting of 30 minutes of exercise during the first two hours of dialysis with three times a week frequency, on the quality of life (QoL), level of depression/anxiety and physical performance in hemodialysis (HD) patients. Methods: The clinical, longitudinal, prospective study with one-group repeated measures design was conducted during a 16-week period. A convenience sample of 52 HD patients, who had been on HD for a minimum of 6 months, were included. QoL, level of depression and anxiety (questionnaires: SF-36, Back Depression Inventory (BDI) and Back Anxiety Inventory (BAI)) and physical performance (modifying Visual Analogue Scale (VAS) and Manual Muscle Testing (MMT)) were assessed at baseline and after 4-month exercise program. Results: The following scales of SF-36 questionnaire were improved after 16-week exercise program: role functioning/emotional (P=0.018), energy/fatigue (P=0.002) and social functioning (P=0.030). Level of depression and anxiety were significantly decreased in males (P=0.007 and P=0.022, respectively) and females (P=0.001 and P=0.000, respectively). VAS scale and MMT were significantly increased in males (P=0.000 and P=0.001, respectively) and females (P=0.019 and P=0.001, respectively) after 16-week exercise program. Conclusion: Exercise program improves some aspects of QoL and physical performance, and decreases the level of depression and anxiety in HD patients

Molecular structure of the largemouth bass (Micropterus salmoides) Myf5 gene and its effect on skeletal muscle growth

Myogenic Regulatory Factors (MRFs), a family of basic helix-loop-helix (bHLH) transcription factors, play important roles in regulating skeletal muscle development and growth. Myf5, the primary factor of MRFs, initiates myogenesis. Its expression pattern during somitomyogenesis in some fish has been revealed. To further study its effect on fish muscle during postembryonic growth, characterization and function analysis of myf5 cDNA were carried out in largemouth bass. The 1,093 bp cDNA sequence was identified by RT-PCR and 3′RACE, then the ORF of Myf5 cDNA was cloned into the expression vector pcDNA3.1(−)/mycHisB. The recombinant plasmid pcDNA3.1(−)/mycHisB-Myf5 was injected into the dorsal muscle of tilapias. RT-PCR and histochemical results showed that the exogenous gene was transcribed and translated in vivo. Its effect on muscle growth focused on myofiber hypertrophy in white muscle 60 days post injection. This indicated that overexpression of Myf5 can promote myogenesis during the fish muscle postembryonic growth period

Smooth muscle fascicular reorientation is required for esophageal morphogenesis and dependent on Cdo.

Postnatal maturation of esophageal musculature involves proximal-to-distal replacement of smooth muscle with skeletal muscle by elusive mechanisms. We report that this process is impaired in mice lacking the cell surface receptor Cdo and identify the underlying developmental mechanism. A myogenic transition zone containing proliferative skeletal muscle precursor cells migrated in a proximal-distal direction, leaving differentiated myofibers in its wake. Distal to the transition zone, smooth muscle fascicles underwent a morphogenetic process whereby they changed their orientation relative to each other and to the lumen. Consequently, a path was cleared for the transition zone, and smooth muscle ultimately occupied only the distal-most esophagus; there was no loss of smooth muscle. Cdo(-/-) mice were specifically defective in fascicular reorientation, resulting in an aberrantly proximal skeletal-smooth muscle boundary. Furthermore, Cdo(-/-) mice displayed megaesophagus and achalasia, and their lower esophageal sphincter was resistant to nitric oxide-induced relaxation, suggesting a developmental linkage between patterning and sphincter function. Collectively, these results illuminate mechanisms of esophageal morphogenesis and motility disorders