FLASH free-electron laser single-shot temporal diagnostic: terahertz-field-driven streaking

We report on the commissioning of a terahertz (THz) field driven streak camera installed at the free-electron laser FLASH at DESY in Hamburg, being able to deliver the photon pulse duration as well as the arrival time information with around 10 fs resolution for each single XUV FEL pulse. Pulse durations between 300 fs and <15 fs have been measured for different FLASH FEL settings. A comparison between the XUV pulse arrival time and the FEL electron bunch arrival time measured at the FLASH linac section - exhibit a correlation width of 20 fs rms, thus demonstrating the excellent operation stability of FLASH. In addition, the THz streaking setup was operated simultaneously to an alternative method to determine the FEL pulse duration based on spectral analysis. FLASH pulse duration, derived from simple spectral analysis, are in good agreement with that from THz streaking measurement

Non-invasive online wavelength measurements at FLASH2 and present benchmark

At FLASH2, the free-electron laser radiation wavelength is routinely measured by an online spectrometer based on photoionization of gas targets. Photoelectrons are detected with time-of-flight spectrometers and the wavelength is determined by means of well known binding energies of the target species. The wavelength measurement is non-invasive and transparent with respect to running user experiments due to the low gas pressure applied. Sophisticated controls for setting the OPIS operation parameters have been created and integrated into the distributed object-oriented control system at FLASH2. Raw and processed data can be stored on request in the FLASH data acquisition system for later correlation with data from user experiments or re-analysis. In this paper, the commissioning of the instrument at FLASH2 and the challenges of space charge effects on wavelength determination are reported. Furthermore, strategies for fast data reduction and online data processing are presented

A biominősítés hatása a fogyasztók érzékelésére és attitűdjére csokoládék esetén

The time–energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modu- lations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science

Matter manipulation with extreme terahertz light: Progress in the enabling THz technology

Terahertz (THz) light has proven to be a fine tool to probe and control quasi-particles and collective excitations in solids, to drive phase transitions and associated changes in material properties, and to study rotations and vibrations in molecular systems. In contrast to visible light, which usually carries excessive photon energy for collective excitations in condensed matter systems, THz light allows for direct coupling to low-energy (meV scale) excitations of interest, The development of light sources of strong-field few-cycle THz pulses in the 2000s opened the door to controlled manipulation of reactions and processes. Such THz pulses can drive new dynamic states of matter, in which materials exhibit properties entirely different from that of the equilibrium. In this review, we first systematically analyze known studies on matter manipulation with strong-field few-cycle THz light and outline some anticipated new results. We focus on how properties of materials can be manipulated by driving the dynamics of different excitations and how molecules and particles can be controlled in useful ways by extreme THz light. Around 200 studies are examined, most of which were done during the last five years. Secondly, we discuss available and proposed sources of strong-field few-cycle THz pulses and their state-of-the-art operation parameters. Finally, we review current approaches to guiding, focusing, reshaping and diagnostics of THz pulses. (C) 2019 The Author(s). Published by Elsevier B.V

Budget analysis of Bosiljevo Municipality

Proračun predstavlja glavni financijski instrument države kojim se planiraju prihodi i primici te utvrđuju rashodi izdaci za proračunsku godinu. Osim što je ključan dokument za državu, proračun je neophodan i za jedinice lokalne i regionalne (područne) samouprave. U diplomskom radu predmet istraživanja je analiza proračuna jedinica lokalne samouprave, a za analizu je odabran primjer proračuna općine Bosiljevo. Cilj diplomskog rada je analizirati i dati detaljniji pregled proračuna općine Bosiljevo za 2019. godinu. Analiziran je opći dio proračuna za 2019. godinu koji sadrži račun prihoda i rashoda raspoređen prema ekonomskoj klasifikaciji, isto tako analiziran je posebni dio proračuna prema organizacijskoj i programskoj klasifikaciji. Razmotren je i analiziran plan razvojnih programa općine za 2019. godinu s projekcijama za 2020. i 2021. godinu. U radu su također grafički prikazani struktura prihoda i rashoda proračuna iz 2019. godine nakon izmjene i dopune proračuna. Temeljem provedene analize zaključuje se da je proračun općine Bosiljevo planiran prema zakonskim odredbama i propisima uz provedeni rebalans. Općina Bosiljevo utrošena sredstva koristi za razvoj gospodarstva te kako bi unaprijedila kvalitetu stanovanja i života građana u općini

A novel cryogenic machining concept based on a lubricated liquid carbon dioxide

A novel single-channel supply of pre-mixed (a) liquid carbon dioxide (LCO2) and (b) oil – delivered via minimum quantity lubrication (MQL) – represents a significant advancement in cryogenic-machining technology. In this proof-of-concept study, an attempt is made to advance the understanding of the oil solubility in LCO2 and to analyze the oil-droplets and their impact on machining performance. The results indicate that the physical and chemical properties of oil distinctively affect its solubility in LCO2. The achieved solubility further influences the achievable oil-droplet size and distribution and tool life

Lease Accounting on the example of Hypo Alpe-Adria-Leasing Ltd.

Poslovanje leasing društava često se u praksi poistovjećuje s poslovanjem banaka, dok se poslovanje navedenih institucija značajno razlikuje. Za razliku od financiranja putem kredita kojem je na prvom mjestu stjecanje vlasništva, u financiranju putem leasinga na prvom je mjestu korištenje. Tako se razlikuje financijski leasing kojem je osnovni smisao korištenje objekta leasinga sa stjecanjem vlasništva na kraju otplate, dok kod operativnog leasinga objekt leasinga se koristi bez stjecanja vlasništva na kraju. Oba, financijski i operativni leasing, su godinama prisutna na hrvatskom tržištu. Stoga ovaj završni rad obuhvaća karakterizaciju leasinga i primjere računovodstvenog evidentiranja financijskog i operativnog leasinga u leasing društvu Hypo Alpe-Adria-Leasing d.o.o

Film as a way of children`s verbal expression

U današnjem društvu mediji su sastavni dio naših života te upravo zbog toga imaju veliki utjecaj na djecu, odnosno na njihov razvoj te odgoj i obrazovanje. Masovni mediji, film i televizija, mogu biti poticajni model djetetu ako se koriste na pozitivan i ispravan način. Kroz film i televiziju dijete usvaja različita znanja o govoru i izražavanju te razvija komunikacijske, intelektualne i logičke sposobnosti, izgrađuje estetsku kulturu, vizualnu i auditivnu percepciju, a pritom također usvaja moralne i emocionalne vrijednosti. Ovaj završni rad istražuje utjecaje televizije i filma na dijete predškolske dobi. U radu se ukratko obrađuju masovni mediji, konkretno film i televizija te različite vrstefilmova. Naglasak je pritom na animiranom filmu koji je prvenstveno namijenjen djeci. Rad donosi i kratki pregled povijesti hrvatskog animiranog filma. Također se govori o konkretnim animiranim sadržajima koje današnja televizija nudi djeci kao i mogućim utjecajima tih sadržaja na ciljanu dobnu skupinu. Detaljnije se obrađuje odnos djeteta i filma te se govori o tome što film i televizija omogućuju djetetu i koju ulogu u tome imaju roditelji i odgojitelji djeteta. Postoje različiti odnosi djeteta i televizije te različito razumijevanje onoga što se prikazuje na televiziji, što ovisi o djetetovoj dobi. Različiti autori navode mnoge pozitivne, ali i negativne utjecaje filma i televizije na djecu predškolske dobi. Jedan od glavnih pozitivnih utjecaja je onaj na djetetov govor i njegovo govorno izražavanje, kao i mogućnost izražavanja kroz glazbenu, likovnu i dramsku umjetnost.In today's society, the media are an integral part of our lives and that is why they have a great impact on children, and their development and upbringing and education. Mass media, film and television, can be a stimulating model for a child if used in a positive and correct way. Through film and television, the child acquires different knowledge of speech and expression and develops different abilities: communication, intellectual, logical, emotional, moral and aesthetic, as well as his visual and auditory perception. This final paper explores the influences of television and film on the preschool child. The paper briefly deals with the mass media, specifically film and television, and various types of films. It also deals with animated film that is primarily intended for children and the history of Croatian animated film are also covered in order to get an insight into the first animated films. It also talks about what today’s television specifically offers children from animated series and how those series can affect children. The relationship between the child and the film is discussed in more detail, where it is discussed what film and television enable the child and what role the child's parents and educators play in all this. There are different relationships between a child and television and a different understanding of what is shown on television depending on the child's age. Various authors cite a lot of positive, but also a lot of negative influences of film and television on preschool children. One of the main positive influences is the one on the child's speech and his speech expression, as well as the possibility of expression through music, fine and dramatic arts

Machining conditions of cryogenic milling using liquid CO2

V doktorskem delu je predstavljeno kriogeno frezanje (ang. cryogenic milling) z uporabo tekočega ogljikovega dioksida (ang. Liquid Carbon Dioxide – LCO2). Način enokanalnega dovoda (ang. single-channel supply) kriogenega medija, t.j. mešanice (a) LCO2 in (b) olja v obliki oljne megle – MQL (ang. Minimum Quantity Lubrication – MQL) predstavlja pomemben napredek pri kriogenem odrezavanju (ang. cryogenic machining). Hladilna in mazalna sposobnost mešanice LCO2 + olje (MQL), ki neposredno vplivata na odrezovalne razmere, do sedaj nista bili individualno analizirani. V tem delu je zato hladilna sposobnost (ang. cooling capability) kriogenega medija določena s pomočjo nadzorovanega vira toplote za simulacijo procesa odrezavanja. Mazalna sposobnost (ang. lubrication capability) kriogenega medija pa je določena preko detajlne analize toka kriogenega medija. Rezultati kažejo, da ima kriogeni medij nižjo hladilno sposobnost, kot konvencionalna emulzija na bazi olja (ang. oil based emulsion). To se odraža v višji temperaturi odrezavanja (ang. cutting temperature) pri uporabi kriogenega medija. Kljub temu, najdaljšo obstojnost orodja dosežemo pri kriogenem odrezavanju, kar nakazuje na pomembnost zadostnega hlajenja. Hkrati je pomembno tudi mazanje, ki je najustreznejše ob uporabi nepolarnega olja v mešanici LCO2 + olje (MQL). Nadalje, ugotovljeno je, da uporaba mešanice LCO2 + olje (MQL) ne vpliva negativno na obliko odrezkov. Zaradi značilno daljše obstojnosti orodja pa je kriogeno odrezavanje stroškovno ugodnejše od konvencionalnega odrezavanja. Predstavlja tudi varno tehnologijo odrezavanja, saj koncentracija CO2 v zraku v bližini CNC stroja, ne presega dovoljenih vrednosti.In the following doctoral thesis, cryogenic milling using liquid carbon dioxide (LCO2) is presented. A novel single-channel supply of pre-mixed (a) LCO2 and (b) oil – delivered as a minimum quantity lubrication (MQL) – represents a significant advancement of cryogenic-machining technology. Cooling and lubrication capability of the mixture LCO2 + oil (MQL), which directly affects the machining conditions, have not been individually analyzed so far. Therefore, in this thesis, cooling capability of the cryogenic media was determined utilizing a controlled heat source for simulating the machining process. Lubrication capability of the cryogenic media was determined by advanced cryogenic media streamflow analysis. Results are showing that cryogenic media offers lower cooling capability than conventional oil based emulsion. This is further reflected in a higher cutting temperature, when the cryogenic media is employed. Nevertheless, the longest tool life is achieved in cryogenic machining, which indicates the importance of sufficient cooling. In addition, lubrication plays an important rolethe most suitable lubrication provides nonpolar oil in the mixture of LCO2 + oil (MQL). Furthermore, the use of mixture LCO2 + oil (MQL) was found not to adversely affect the chip shapes. Moreover, due to the significantly longer tool life, cryogenic machining is more cost-effective than conventional machining. It is also a safe machining technology, since the CO2 concentration in the air near the CNC machine, does not exceed the permitted values