The Doppler effect in an accelerated system and determining the acceleration of a sound source

Tijekom studija i u srednjoj školi Dopplerov efekt se obraduje i matematički opisuje za specifičan slučaj kad se izvor zvuka i opažač gibaju konstantnim relativnim brzinama. U ovom diplomskom radu će se pokušati opisati slučaj kad ta brzina nije konstantna, već se mijenja u vremenu. Konkretnije; razmotrit će se slučaj kad izvor zvuka jednoliko ubrzava, a opažač miruje. U skladu s tim pokušat će se teorijski predvidjeti kako se frekvencija koju registrira opažač mijenja za vrijeme ubrzavanja izvora zvuka, a zatim isto i eksperimentalno provjeriti te usporediti teorijsko predviđanje s dobivenim eksperimentalnim podacima. Pri eksperimentalnoj realizaciji je za uzrok jednoliko ubrzanog gibanja odabrana isključivo jedna sila, naime, gravitacijska sila. Budući da neke sile poput otpora zraka i sl. nisu mogle biti eksperimentalno eliminirane, akceleracija izvora zvuka nije mogla biti jednaka akceleraciji slobodnog pada, odnosno 9,81 m/s2, već je neizbježno morala biti nešto manja. Iz tog razloga se uz analizu zvuka provodila i analiza videozapisa akcelerirajućeg izvora zvuka, a iz koje je potom određena najvjerojatnija stvarna akceleracija izvora zvuka. Konačno, u ovom će se radu usporediti dobivene akceleracije izvora zvuka kao rezultati analiza videozapisa te zvučnog zapisa s pretpostavkom veće točnosti rezultata dobivenog analizom videozapisa te ocijeniti kakvoća analize Dopplerovog efekta za određivanje akceleracije jednoliko ubrzanog tijela.In secondary school and college physics courses the Doppler effect is studied and calculated in a specific case in which a sound source and observer are moving at a constant relative velocity. This thesis will try to describe the case in which the velocity is not constant but changes with time. More precisely, it will analyze the case of a uniformly accelerated sound source and a stationary observer. In accordance with that, the thesis will try to theoretically predict the changes in frequency measured by the observer during the acceleration of the sound source. This prediction will then be experimentally verified and the obtained data will be compared to the theoretical prediction. There is only one cause of uniformly accelerated motion of the sound source in our experimental setup: gravity. Considering the fact that air resistance and other disturbances could not be experimentally eliminated, inevitably the sound source acceleration had to be below the free fall acceleration of 9; 81 m/s2. For that reason, the video material with the falling sound source was examined alongside sound analysis to determine the most likely actual acceleration. Finally, this paper will compare the sound source accelerations obtained by both sound and video analyses, which accounts for greater accuracy of results, and evaluate the quality of the Doppler effect analysis for determining the acceleration of a uniformly accelerated body

NEPRUŽANJE LIJEČNIČKE POMOĆI

Liječničke greške moguće klasificirati prema različitim kriterijima s tim da osnovna podjela kreće od onih koji su nastali činjenjem i onih koji su nastali nečinjenjem. Liječničke pogreške možemo još podijeliti i na grube ili teže i lakše; na greške po stadijima medicinske intervencije, dijagnostičke, terapijske, profilaktičke; na tehničke i taktičke; na opće, elementarne, u organizaciji rada, u informiranju itd. Jedno od oblika liječničke pogreške nastale nečinjenjem (propuštanjem) je i nepružanje medicinske pomoći. Kod ove vrste liječničke greške ključno je pitanje: kada nastaje obveza liječnika da ukaže liječničku pomoć? Radi se o nepružanju neodgodive medicinske pomoći osobi kojoj je takva pomoć potrebna zbog izravne opasnosti za njezin život. Liječnička radnja u danoj situaciji nameće se kao hitna, neizostavna, neizbježna, čije propuštanje može dovesti do ugrožavanja pacijentovog života. Autori ovog rada nastoje prikazati koji su elementi ovog oblika liječničke pogreške i način njihova ostvarivanja, budući je to od izuzetne važnosti zbog velikog broja dvojbi o postojanju ili nepostojanju liječničke pogreške u praksi.Medical malpractice can be classified according to different criteria, provided by that the basic divisions ranging from those that were created by acts and those incurred by omission. Medical errors can still divide and on rough or difficult and easier; on-error stages of medical intervention, diagnostic, therapeutic, prophylactic; the technical and tactical; in general, elementary, organized labor, the information and so on. One of the forms of medical errors caused by omission (failing) is lack of medical care. Key issue is: when the doctors obligation to take care of pacient starts. It is the failure to provide immediate medical care the person from whom such care is required because of direct threats to her life. Medical action in a given situation imposed as urgent, indispensable, unavoidable, whose failure can lead to compromising the patient\u27s life. The authors seek to show that the elements of this form of medical malpractice and way of their realization, as it is of the utmost importance because of the large number of doubts about the existence or non-existence of medical malpractice in practice

Wavefunction Embedding for Molecular Polaritons

Polaritonic chemistry relies on the strong light-matter interaction phenomena for altering the chemical reaction rates inside optical cavities. To explain and to understand these processes, the development of reliable theoretical models is essential. While computationally efficient quantum electrodynamics self-consistent field (QED-SCF) methods, such as quantum electrodynamics density functional theory (QEDFT) needs accurate functionals, quantum electrodynamics coupled cluster (QED-CC) methods provide a systematic increase in accuracy but at much greater cost. To overcome this computational bottleneck, herein we introduce and develop the QED-CC-in-QED-SCF projection-based embedding method that inherits all the favorable properties from the two worlds, computational efficiency and accuracy. The performance of the embedding method is assessed by studying some prototypical but relevant reactions, such as methyl transfer reaction, proton transfer reaction, as well as protonation reaction in a complex environment. The results obtained with the new embedding method are in excellent agreement with more expensive QED-CC results. The analysis performed on these reactions indicate that the strong light-matter interaction is very local in nature and that only a small region should be treated at the QED-CC level for capturing important effects due to cavity. This work sets the stage for future developments of polaritonic quantum chemistry methods and it will serve as a guideline for development of other polaritonic embedding models