Numerical and Experimental Vibration Analysis of a Steam Turbine Rotor Blade

Damage to the rotor blade of a steam turbine is a relatively common problem and is one of the leading causes of sudden and unplanned shutdowns of a steam turbine. Therefore, the high reliability of the rotor blades is very important for the safe and economical operation of the steam turbine. To ensure high reliability, it is necessary to perform a vibration analysis of the rotor blades experimentally and in a computer environment. In this paper, a modal analysis was performed on the twisted blade of the last stage of the turbine in the Ansys software. The results of the modal analysis of the stationary rotor blade were compared with the results obtained by the bump test, which confirmed the numerical model of the blade. A modal analysis of a rotating rotor blade was performed on the same numerical model, and Campbell diagrams were plotted to determine the critical speed

PRISTUP KUPCU I PREZENTACIJA PROIZVODA NA POSLOVNOM TRŽIŠTU : završni rad

Rad ne sadrži sažetak

PRISTUP KUPCU I PREZENTACIJA PROIZVODA NA POSLOVNOM TRŽIŠTU : završni rad

Rad ne sadrži sažetak

Uloga standardne video-kromokolonoskopije u razlikovanju adenomatoznih od neadenomatoznih sitnih kolorektalnih polipa

To date, there are no reliable endoscopic criteria to discriminate a diminutive (<5 mm) colorectal adenomatous from nonadenomatous polyps. Studies have demonstrated the usefulness of high-resolution chromoendoscopy (high-resolution colonoscopy with topically applied indigo carmine dye) in discrimination of adenomatous from nonadenomatous colorectal polyps. However, the clinical utility of standard videocolonoscopy and chromoscopy with indigo carmine dye in differentiating diminutive colorectal polyps has not yet been completely defined. The aim of this study was to determine whether a combination of standard videocolonoscopy and staining with indigo carmine dye could differentiate between adenomatous and nonadenomatous colorectal polyps smaller than 5 mm. Colonoscopy by use of an Olympus EVIS 140 video system was performed in 42 patients in whom colorectal polyps smaller than 5 mm were found. Polyps were sprayed with up to 40 ml of 0.5% indigo carmine dye, and polypectomy was performed, and the material was referred for histology. In 42 patients included in the study, 48 polyps sized <5 mm were detected. Histologic analysis showed 14 of them to be adenomatous and 34 nonadenomatous polyps. Endoscopist\u27s diagnosis was confirmed by histology in 12 of 14 (85.7%) adenomatous and 31 of 34 (91.2%) nonadenomatous colorectal diminutive polyps. The sensitivity, specificity, positive predictive value and negative predictive value of standard videochromocolonoscopy in distinguishing between adenomatous and nonadenomatous polyps sized <5 mm were 85.7%, 91.2%, 80% and 93.9%, respectively. The likelihood ratios (LR) were 0.157 (LR-) and 9.74 (LR+). In conclusion, standard videocolonoscopy combined with indigo carmine dye is a reliable method to differentiate adenomatous from nonadenomatous colorectal polyps sized <5 mm. Such a technique could limit the requests for unnecessary biopsies and repeat colonoscopy, thus significantly reducing the cost of colorectal cancer screening.Danas ne postoje pouzdani endoskopski kriteriji koji bi razlikovali sitne (<5 mm) kolorektalne adenomatozne od neadenomatoznih polipa. Ranije su studije pokazale korisnu uporabu visoko-rezolucijske kromoendoskopije (visoko-rezolucijska kolonoskopija s topičkom primjenom indigo crvene boje) u razlikovanju adenomatoznih od neadenomatoznih kolorektalnih polipa. Ipak, klinička upotreba standardne video-kolonoskopije i kromoskopije s indigo crvenom bojom u razlikovanju sitnih kolorektalnih polipa nije još potpuno utvrđena. Namjera ovoga ispitivanja bila je utvrditi može li se kombinacijom standardne video-kolonoskopije i bojanja indigo crvenom bojom razlikovati adenomatozne od neadenomatoznih kolorektalnih polipa manjih od 5 mm. Kolonoskopija uz primjenu video sustava Olympus EVIS 140 izvedena je u 42 bolesnika u kojih su nađeni kolorektalni polipi manji od 5 mm. Polipi su poprskani 0,5%-tnom indigo crvenom bojom u količini do 40 mL, izvedena je polipektomija i provedena histološka analiza. U 42 bolesnika uključenih u ispitivanje nađeno je 48 polipa manjih od 5 mm. Histološka analiza pokazala je postojanje 14 adenomatoznih i 34 neadenomatoznih polipa. Endoskopist je ispravno predvidio histološki nalaz u 12 od 14 (85,7%) adenomatoznih, te u 31 od 34 (91,2%) neadenomatoznih kolorektalnih sitnih polipa.Osjetljivost, specifičnost, pozitivna prediktivna vrijednost i negativna prediktivna vrijednost standardne video-kromokolonoskopije u razlikovanju adenomatoznih od neadenomatoznih polipa manjih od 5 mm bile su 85,7%, 91,2%, 80%, odnosno 93,9%. Omjer vjerojatnosti (LR) iznosio je 0,157 (LR-) i 9,74 (LR+). Standardna video-kolonoskopija u kombinaciji s indigo crvenom bojom pouzdana je metoda za razlikovanje adenomatoznih od neadenomatoznih kolorektalnih polipa manjih od 5 mm. Ovakvom bi se tehnikom mogli smanjiti zahtjevi za nepotrebnim biopsijama i opetovanim kolonoskopijama, te tako značajno sniziti troškovi probiranja na kolorektalni karcinom

Uloga standardne video-kromokolonoskopije u razlikovanju adenomatoznih od neadenomatoznih sitnih kolorektalnih polipa

To date, there are no reliable endoscopic criteria to discriminate a diminutive (<5 mm) colorectal adenomatous from nonadenomatous polyps. Studies have demonstrated the usefulness of high-resolution chromoendoscopy (high-resolution colonoscopy with topically applied indigo carmine dye) in discrimination of adenomatous from nonadenomatous colorectal polyps. However, the clinical utility of standard videocolonoscopy and chromoscopy with indigo carmine dye in differentiating diminutive colorectal polyps has not yet been completely defined. The aim of this study was to determine whether a combination of standard videocolonoscopy and staining with indigo carmine dye could differentiate between adenomatous and nonadenomatous colorectal polyps smaller than 5 mm. Colonoscopy by use of an Olympus EVIS 140 video system was performed in 42 patients in whom colorectal polyps smaller than 5 mm were found. Polyps were sprayed with up to 40 ml of 0.5% indigo carmine dye, and polypectomy was performed, and the material was referred for histology. In 42 patients included in the study, 48 polyps sized <5 mm were detected. Histologic analysis showed 14 of them to be adenomatous and 34 nonadenomatous polyps. Endoscopist\u27s diagnosis was confirmed by histology in 12 of 14 (85.7%) adenomatous and 31 of 34 (91.2%) nonadenomatous colorectal diminutive polyps. The sensitivity, specificity, positive predictive value and negative predictive value of standard videochromocolonoscopy in distinguishing between adenomatous and nonadenomatous polyps sized <5 mm were 85.7%, 91.2%, 80% and 93.9%, respectively. The likelihood ratios (LR) were 0.157 (LR-) and 9.74 (LR+). In conclusion, standard videocolonoscopy combined with indigo carmine dye is a reliable method to differentiate adenomatous from nonadenomatous colorectal polyps sized <5 mm. Such a technique could limit the requests for unnecessary biopsies and repeat colonoscopy, thus significantly reducing the cost of colorectal cancer screening.Danas ne postoje pouzdani endoskopski kriteriji koji bi razlikovali sitne (<5 mm) kolorektalne adenomatozne od neadenomatoznih polipa. Ranije su studije pokazale korisnu uporabu visoko-rezolucijske kromoendoskopije (visoko-rezolucijska kolonoskopija s topičkom primjenom indigo crvene boje) u razlikovanju adenomatoznih od neadenomatoznih kolorektalnih polipa. Ipak, klinička upotreba standardne video-kolonoskopije i kromoskopije s indigo crvenom bojom u razlikovanju sitnih kolorektalnih polipa nije još potpuno utvrđena. Namjera ovoga ispitivanja bila je utvrditi može li se kombinacijom standardne video-kolonoskopije i bojanja indigo crvenom bojom razlikovati adenomatozne od neadenomatoznih kolorektalnih polipa manjih od 5 mm. Kolonoskopija uz primjenu video sustava Olympus EVIS 140 izvedena je u 42 bolesnika u kojih su nađeni kolorektalni polipi manji od 5 mm. Polipi su poprskani 0,5%-tnom indigo crvenom bojom u količini do 40 mL, izvedena je polipektomija i provedena histološka analiza. U 42 bolesnika uključenih u ispitivanje nađeno je 48 polipa manjih od 5 mm. Histološka analiza pokazala je postojanje 14 adenomatoznih i 34 neadenomatoznih polipa. Endoskopist je ispravno predvidio histološki nalaz u 12 od 14 (85,7%) adenomatoznih, te u 31 od 34 (91,2%) neadenomatoznih kolorektalnih sitnih polipa.Osjetljivost, specifičnost, pozitivna prediktivna vrijednost i negativna prediktivna vrijednost standardne video-kromokolonoskopije u razlikovanju adenomatoznih od neadenomatoznih polipa manjih od 5 mm bile su 85,7%, 91,2%, 80%, odnosno 93,9%. Omjer vjerojatnosti (LR) iznosio je 0,157 (LR-) i 9,74 (LR+). Standardna video-kolonoskopija u kombinaciji s indigo crvenom bojom pouzdana je metoda za razlikovanje adenomatoznih od neadenomatoznih kolorektalnih polipa manjih od 5 mm. Ovakvom bi se tehnikom mogli smanjiti zahtjevi za nepotrebnim biopsijama i opetovanim kolonoskopijama, te tako značajno sniziti troškovi probiranja na kolorektalni karcinom

STUDENT SUCCESS PREDICTION USING ARTIFICIAL NEURAL NETWORKS

Višegodišnja elektronička obrada podataka omogućila je pohranu velike količine podataka koja se danas može iskoristiti za poboljšanje procesa u obrazovanju putem algoritama strojnog učenja. Koristeći se podacima iz sustava Moodle za učenje na daljinu, stvoren je model umjetne neuronske mreže s ciljem predviđanja konačnog ishoda studenta na kraju studija na temelju njegovih zaključnih ocjena prve godine studija. Kroz ukupno tri modela umjetne neuronske mreže pokazana je snaga ovog algoritma, gdje su svi modeli ostvarili vrlo nisku pogrešku, a najbolji rezultati postignuti su modelom umjetne neuronske mreže s dva skrivena sloja od devet neurona, čija je apsolutna greška iznosila 0,1920, a kvadratna pogreška 0,0562. Istraživanje pokazuje da su umjetne neuronske mreže vrlo učinkovite u predikciji konačnog ishoda studenata na temelju ocjena s prve godine studija te da takvi modeli imaju potencijal postati pomoćni alat i sredstvo donošenja odluka u obrazovnim institucijama.Many years of electronic data processing have enabled the storage of a large amount of data that can be used today to improve educational processes through machine learning algorithms. Using data from the Moodle distance learning system, an artificial neural network model was created to predict the final outcome of students at the end of their studies based on their final grades of the first year of study. In three artificial neural network models, the power of this algorithm was demonstrated, where all models achieved a very low error, and the artificial neural network model achieved the best results with two hidden layers of nine neurons, whose absolute error was 0.1920, and the squared error 0.0562. The research shows that artificial neural networks are very effective in predicting the final outcome of students based on the grade from the first year of study and that such models have the potential to become an auxiliary tool and means of decision-making in educational institutions

Liječenje polipa žučnoga mjehura: prijedlog optimalne strategije

Polypoid lesions of the gallbladder can be divided into benign and malignant lesions. Benign polypoid lesions of the gallbladder are divided into tumors and pseudotumors. Pseudotumors make up the majority of polypoid lesions of the gallbladder. They can occur in the form of polyps, hyperplasia or other miscellaneous lesions. Adenomas are the most common benign neoplasms of the gallbladder. Ultrasound has been demonstrated to be significantly better in detecting polypoid lesions of the gallbladder as compared with computed tomography and cholecystography. Recommendations for an optimal strategy in the management of gallbladder polyps are presented. Generally, no treatment is required in a young patient with very small gallbladder polyps, who is completely free from symptoms. In patients with unequivocal recurrent biliary colic, elective cholecystotomy is warranted, especially in case of coexistence of stones and polyps. Cholecystectomy is also indicated in patients with gallbladder polyps greater than 10 mm, irrespective of symptomatology. In patients with gallbladder polypoid lesions smaller than 10 mm, cholecystectomy is only indicated if complicating factors are present, e.g., age ³ 50 and coexistence of gallstones. If a gallbladder polyp is smaller than 10 mm and if complicating factors are absent, the “watch-and-wait” strategy seems to be recommendable.Polipoidne lezije žučnoga mjehura mogu se podijeliti u benigne i maligne. Benigne polipoidne lezije dijele se na prave tumore i pseudotumore. Pseudotumori čine većinu polipoidnih lezija žučnoga mjehura, a mogu se očitovati kao polipi, hiperplazija ili druge različite lezije. Adenomi predstavljaju najčešće benigne neoplazme žučnoga mjehura. Pokazalo se da je ultrazvuk značajno bolji u otkrivanju polipoidnih lezija žučnoga mjehura u usporedbi s kompjutoriziranom tomografijom i kolecistografijom. U ovom su radu prikazane preporuke za optimalnu strategiju praćenja i obrade polipa žučnoga mjehura. Općenito, u mladog bolesnika s polipima žučnoga mjehura manjim od 10 mm i bez simptoma nije potrebna nikakva terapija. U bolesnika s jasnim kolikama elektivna kolecistektomija je opravdana, poglavito ako su uz polipe prisutni i žučni kamenci. Kolecistektomija je također indicirana u bolesnika s polipima većim od 10 mm, bez obzira na simptomatologiju. U bolesnika s polipima manjim od 10 mm kolecistektomija je indicirana samo ako se radi o bolesnicima starijim od 50 godina i/ili ako su istodobno prisutni i žučni kamenci. Kad su polipi žučnoga mjehura manji od 10 mm i ako se radi o bolesnicima mlađim od 50 godina u kojih nije moguće dokazati žučne kamence, preporučujemo strategiju ‘pratiti i čekati’

Quality Management: Patients Reflections on Health Care at Outpatient Clinic of Internal Medicine Department

Middle and older age group relative share in the community permanently grows. Those are commonly burdened with several chronic health conditions or elevated incidence of acute ones and in more frequent need for consulting health services. In the era of modern technical medicine, it is important to increase quality of services particularly patients orientated. Department of Internal medicine developed questionnaire to assess reflections on medical care from the receiver of medical services point of view. Sample was formed from individuals that visited outpatient triage Unit (OTU) and voluntary enrolled, during period April 1 – August 31 2008 for any medical reason. Study population structure had similarly equally of both genders, socio-economical background, and was in age range 18–87. Questionnaire was developed by team of experienced personnel covering satisfaction on received medical care. There were 279 returned formulary in a sample of 6700 patients (4.18%). Patients visited OTU chiefly on behalf medical condition secondary to address of residency, followed by personal choice, on advice given by general practitioner, by emergency transportation services, or just due to earlier experiences. Regarding provided medical care extent, 4/5 of patients were examined in lesser than 2 hours, while total workup lasted mostly for 2–4, followed by over four. Over half of patients were moderate toward highly satisfied with provided medical information, personnel communication style and general reflection on all services while being in the Department premises. Astonishing proportion of patients (93%) was satisfied with positive personnel communication. Integration of patients’ self-perceived reports about medical services in organizing process is inevitable for augmenting content and at the same time valuable for developing overall quality of treatment. Communication excellence is of premier importance and unavoidable for giving additional positive effect to remain health status or to ease the healing process of individual and their families

The impact of zno nanoparticles application on yield components of different wheat genotypes

The properties of zinc oxide nanoparticles (ZnO NPs) and their use have been shown as prominent for application in agriculture since it can bring certain benefits in agricultural production. The objective of this study was to estimate the impact of seed priming with ZnO NPs on yield components, plant height and spike length on wheat. In order to estimate the effects of ZnO nanoparticles on yield component, four winter wheat genotypes namely, NS Pobeda, NS Futura, NS 40S and NK Ingenio were selected. Seeds of each wheat genotypes were primed with different concentrations of ZnO NPs (0, 10, 100 and 1000 mg l-1) for 48 h in dark box by continuous aeration. Primed seeds were after sown in soil pots with 60-70% moisture contents during the till maturity. Considerable improvement was observed in plant height and spike length which increased with rates of ZnO NPs compared to the control. At rates of 10 mg l-1 ZnO NPs, the greatest increases in plant height and spike length were observed for genotypes NS Pobeda and NS Futura. At 100 mg l-1 ZnO NPs, the greatest increase for both traits was observed for genotypes NS 40S and NK Ingenio. Maximum rates of ZnO nanoparticles reduced both observed traits of wheat. The result indicated that ZnO nanoparticles can significantly increase plant height and spike length of wheat, but also plant response to ZnO nanoparticles significantly depends on concentration of application, as well as from wheat genotype

Sekundarna arterijsko-enterična fistula: prikaz slučaja i pregled literature

Arterio-enteric fistula is a rare, but potentially deadly cause of gastrointestinal bleeding. The disease occurs in two forms: primary as a result of atherosclerotic aortic aneurysm, aortitis, trauma, radiation, tumor invasion or penetrating ulcer, and secondary as a consequence of surgical aortal reconstruction. The clinical manifestation is mostly gastrointestinal bleeding, rarely back pain, fever and sepsis. Computed tomography with contrast medium is the most suitable diagnostic test, however, the diagnosis frequently requires explorative laparotomy. A case is presented of secondary arterio-enteric fistula, found two years after surgical treatment of chronic pancreatitis with pseudocystojejunostomy, which clinically manifested with gastrointestinal bleeding. Although there was strong suspicion of arterio-enteric fistula, the diagnosis was not verified by routine workup, but only on explorative laparotomy.Arterijsko-enterična fistula je rijedak, ali potencijalno smrtonosan uzrok krvarenja iz probavnog sustava. Bolest se javlja u dva oblika: kao primarna, nastala kao rezultat aterosklerotski promijenjene aneurizme aorte, aortitisa, traume, zračenja, invazije tumora ili penetrirajućeg ulkusa, te kao sekundarna, odnosno posljedica kirurške rekonstrukcije aorte. Klinički se najčešće manifestira u vidu krvarenja iz probavnog sustava, rjeđe bolovima u leđima, vrućicom i sepsom. Najprikladniji dijagnostički test je kompjutorizirana tomografija, no sama dijagnoza se često postavlja tek eksploracijskom laparotomijom. Prikazuje se slučaj sekundarne arterijsko-enterične fistule nađene dvije godine nakon kirurškog liječenja kroničnog pankreatitisa pseudocistojejunostomijom, koja se klinički manifestirala gastrointestinalnim krvarenjem. Iako je postojala velika sumnja na arterijsko-enteričnu fistulu dijagnoza se nije mogla potvrditi standardnim dijagnostičkim postupcima, nego tek na eksploracijskoj laparotomiji