Investigating the Human Factor in Maritime Accidents: A Focus on Compass-Related Incidents

Accidents at sea can have devastating consequences, and investigating their causes is a complex and rigorous process. One of the most important factors contributing to these accidents is the human factor, which has received considerable attention from researchers in recent years. This article examines the role of the human factor in marine accidents, focusing the use and maintenance of compasses. Using data from scientific journals and safety analysis reports, the frequency and focus of research on this topic is analyzed and areas for further investigation are identified. International regulations, performance standards, and handling requirements relating to compasses are also discussed, and an analysis of compass-related accidents is presented. The survey conducted among seafarers indicates that they are satisfied with the performance of their compass, but there is a need for more advanced compass technologies and training on the proper use and maintenance of compasses. The survey shows that routine maintenance and calibration of compasses is crucial to minimize the possibility of human error and to prevent maritime accidents. In conclusion, we stress the importance of conducting further studies in this area taking into account the human factor in order to improve maritime safety measures

Northern Velebit (Croatia) karst hydrological system: results of a preliminary 2H and 18O stable isotope study

Researching the hydrogeological properties of karst systems is very challenging due to their extreme heterogeneity. A grey-box approach in karst research combines the results from classical hydrogeological methods with direct observations within the karstic underground, i.e. in the caves. Isotope research has become a widely used method in the investigation of karst systems. The results presented are of a preliminary 2H and 18O stable isotope study of the Northern Velebit karst system (Croatia) employing the grey-box approach. Groundwater samples were collected during two summer expeditions in deep caves within the karst massif. Monthly precipitation samples were also collected (at three locations between approx. 900 m and 1600 m altitude), as well as water samples at some of the most significant springs, i.e. discharge outlets of the system. For a single expedition, the stable isotope composition is almost constant, i.e. the stable isotope measurements are within the measurement error across the complete cave profile. Similar characteristics across different caves during the same year were also noted. Samples of water from the springs were taken during base-flow conditions and they have similar isotopic contents to the cave water. The results obtained indicate that homogenization of the water already occurs within the subsurface epikarst zone above the sampling locations in the caves, but a future extended sampling campaign during variable hydrologic conditions is needed to confirm this. The final research goal is to establish a conceptual grey-box model for the functioning of this complex hydrogeological system.</p

Primarni zloćudni melanom sluznice usne šupljine

Primary oral malignant melanoma usually presents as a dark brown or black lesion. It is a rare malignancy, accounting for less than 1% of all melanomas and 1.6% of all head and neck malignancies, thus forming up to 0.5% of all oral malignancies in the world literature. In general, the prognosis of oral melanoma is poor and worse than that of cutaneous melanoma. The preferred treatment is radical surgery alone or in combination with radiotherapy, chemotherapy, immunotherapy and immunomodulatory agents. A case is presented of a large malignant melanoma of oral cavity, noticed six months before initial biopsy and by history described as a rapidly growing mass.Primarni melanom sluznice usne šupljine obično je tamno smeđe ili crno pigmentirana lezija. Vrlo je rijetka zloćudna bolest koja se javlja u manje od 1% svih melanoma i čini 1,6% svih maligniteta glave i vrata tvoreći, kako navodi svjetska literatura, do 0,5% svih maligniteta u usnoj šupljini. Općenito, prognoza je lošija nego kod kožnih melanoma. Kirurška resekcija je jedan od najčešćih oblika liječenja, a pokušava se i radioterapijom, kemoterapijom, imunoterapijom i imunomodulatorima. Opisuje se slučaj velikog melanoma u usnoj šupljini ubrzani rast kojega je primijećen šest mjeseci prije biopsije i potvrđene dijagnoze

Computer representation of osteosynthesis stability in locking plates used for the treatment of osteoporotic proximal humerus fractures

Background: Proximal humerus fractures are represented as 4-5% of all fractures, with incidence notably growing with age. Since surgical internal fixation in treatment of proximal humeral fractures is used, fractures of osteoporotic bone and choice of plate for their osteosynthesis represent particular problem. The aim of the study was to test two locking plates: Philos plate with locking screws with determinated direction, and Arthrex plate with poliaxial locking screws, using the finite element method. Subjects and methods: This study used version 6.10 of Abaqus FEA software package for simulation and fine element analysis of Philos and Artrex plates attached to the osteotomy models of proximal humerus with fracture gap at 0°, 10° and 20° in four types of static load: abduction, adduction, axial compression and flexion. Simulation results of loads in abduction, adduction, axial loads and flexion, were described with the total bone displacement (U) and maximum bone displacement in the fracture gap (Uf ). Results: When examining the Philos plate in axial load on the bone with fracture gap angle from 0°, 10° and 20° no significant differences between the results for the displacements were observed. Therefore, results for other loads are related to total displacements of the bone only at the angle of 0°. Given that the results of the total bone displacement and maximum bone displacement in the fracture gap with Artrex plate were mostly higher, for comparison with the results of bone displacement in Philos plate it was taken that total bone displacement and maximum displacement in the fracture gap in Artrex plate represent 100% of the total displacement. Philos plate showed 60.71% for abduction, 76.07% for adduction, 102.24% for axial loads and 79.59% for flexion of total bone displacement in Artrex plate, and 60.48% for abduction, 76.07% for adduction, 96.05% for axial load and 79.96% for flexion of maximum displacement in the fracture gap in Artrex plate. Conclusions: Osteosynthesis for osteoporotic fractures of proximal humerus with Philos plate in computer simulation proved to be more stable than with Arthrex plate

Određivanje elektrokemijskog potencijala Mg anoda

Korozija je nezaobilazna pojava raznih vrsta materijala. Najbrojnija proučavanja i istraživanja se baziraju na koroziju ugljičnih čelika zbog toga jer se oni najviše koriste kod izgradnje raznovrsnih konstrukcija. Korozija se može smanjiti i to do vrijednosti koje su u prihvatljivim razmjerima raznim oblicima antikorozivne zaštite. Završni rad sastoji se od dvije cjeline: teorijski i eksperimentalni dio. U teorijskom dijelu obrađen je princip djelovanja katodne zaštite, tipovi katodne zaštite te anode koje se koriste kod istih. Opisan je i princip mjerenja potencijala sustava te utjecaj lutajućih struja. U eksperimentalnom dijelu ispitivao se elektrokemijski potencijal žrtvovanih anoda Mg i Zn u različitim uvjetima

Katodna zaštita odobalnih konstrukcija

Korozija je nezaobilazna pojava raznih vrsta materijala. \Najbrojnija proučavanja i istraživanja se baziraju na koroziju ugljičnih čelika zbog toga jer se oni najviše koriste kod izgradnje raznovrsnih konstrukcija. Korozija se može smanjiti i to do vrijednosti koje su u prihvatljivim razmjerima što omogućava dugogodišnje korištenje raznih konstrukcija. Diplomski rad sastoji se od dvije cjeline: teorijskog dijela i eksperimentalnog dijela. U teorijskom dijelu obrađen je princip djelovanja katodne zaštite, tipovi katodne zaštite te anode koje se koriste kod istih. Opisana je i problematika katodne zaštite odobalnih konstrukcija. U eksperimentalnom dijelu projektirala se anoda koja će se primjenjivati za katodnu zaštitu odobalnih konstrukcija u uvjetima leda. \Napravljen je laboratorijski sustav katodne zaštite s vanjskim izvorom struje i praćene su polarizacijske krivulje u morskoj vodi i zaleđenoj morskoj vodi. Također, su ispitana mehanička svojstva kompozita koji se koristi kod izrade anode