Optical timing receiver for the NASA laser ranging system. Part 2: High precision time interval digitizer

The development of a high precision time interval digitizer is described. The time digitizer is a 10 psec resolution stop watch covering a range of up to 340 msec. The measured time interval is determined as a separation between leading edges of a pair of pulses applied externally to the start input and the stop input of the digitizer. Employing an interpolation techniques and a 50 MHz high precision master oscillator, the equivalent of a 100 GHz clock frequency standard is achieved. Absolute accuracy and stability of the digitizer are determined by the external 50 MHz master oscillator, which serves as a standard time marker. The start and stop pulses are fast 1 nsec rise time signals, according to the Nuclear Instrument means of tunnel diode discriminators. Firing level of the discriminator define start and stop points between which the time interval is digitized

Evaluation of the amperex 56 TVP photomultiplier

Characteristics were measured for the Amperex 56 TVP 42 mm-diameter photomultiplier. Some typical photomultiplier characteristics-such as gain, dark current, transit and rise times-are compared with data provided. Photomultiplier characteristics generally not available such as the single photoelectron time spread, the relative collection efficiency, the relative anode pulse amplitude as a function of the voltage between the photocathode and focusing electrode, and the position of the photocathode sensing area were measured and are discussed for two 56 TVP's. The single photoelectron time spread, the relative collection efficiency, and the transit time difference as a function of the voltage between photocathode and focusing electrode were also measured and are discussed, particularly with respect to the optimization of photomultiplier operating conditions for timing applications

The Setauket Gang: The American Revolutionary Spy Ring you\u27ve never heard about

Why would some people choose to overlook their apparent differences, ethnicity, religion, gender, and race, and risked being hung to participate in something (spying) where the outcome was not certain? Could they have sensed a moment in history was larger than they were and felt premonition of the new country before it was born? Due to the complex and vibrant environment, a single answer is not possible. The Anglo-American conflict was not as French nor Russian Revolution; instead, it was a gradual transformation of individual social and political views, as Bernard Bailyn argues. The British aggressive imperial policies had a significant impact on the colonial routine. The quasi-independent political environment and accustomed economic dealings were suddenly coming under stricter control of the Westminster. These actions were the antithesis to the constitutional rights of the British subjects and personal want, and people started wondering whether they held the same status as the residents of the British Isles. In good faith, the colonial legislatures, acting for the whole dominion, sent numerous grievances to the Crown, but the ignorance, stubbornness, and want for mastery prevented London from grasping and accepting colonial reasoning. In this environment, the radical ideas, championed by a small group of people, were slowly gaining momentum and becoming a refuge from, and shortly an alternative to, British imperialistic policies. This process would not stop when the new American life was conceptualized in 1776; instead, the British atrocities on the battlefield and conditions in the occupied territory would keep it alive. The Revolution and War for Independence were ideological, but, at the same time, interwoven with personal motivations and experience. Almost all colonials were driven to consider joining the cause by the dominant psychological adjustments, but their own internal motivations pushed them to cut their ties with the Crown permanently. Therefore, if we must distill a single factor for spying during the Revolution, the traditional motives—money, ideology, coercion, and ego (“MICE”)—would be the most accurate. With the ideological motivation more dominant on the side of George Washington and fellow Patriots, and monetary on the British. However, these factors should not be seen as singular motivators. They were entwined with spies’ personal experiences, desires, and grievances

On Negative Silver Iodide Sols in Sodium n-Laurylate Solutions

This paper describes a ·physico-chemical •study of the interaction between the anionic surfactant sodium n-laurylate NaL and the negative stable silver iodide prepared »in statu nascendi«, with emphasis on the colloid properties of the system in aqueous media. Negative stable silver iodide sols of 0.001 M contained NaL solutions from 0.0000001 M to 0.01 M with 0.001 M Na! at 20 °c. Turbidity measurements show the formation of two pronounced Tyndall maxima; eleatmn microscopy and X-ray diffraction analysis data show the dependence of crystallite sizes and sol dens·tties on the concentration of NaL. For the systems examined under ageing the results obtained indicate, as a reasonable possibility, that different effects of NaL on negative silver iodide sol in statu nascendi for systems with NaL below and above the critical micellar concentration can be proposed

Simulacija s celičnimi avtomati – širjenje elektronskega poslovanja v malih organizacijah

This paper describes the cellular automata- based simulation model of electronic commerce diffusion in small organizations. The model and method is verified with historical data. The focus and purpose of the research was to study long-term influences on electronic commerce caused by organisational characteristics in small organisations. Five maturity levels of electronic commerce were defined. The study found that the most influential factor of diffusion is “management support”.The dynamics of electronic commerce introduction and usage in non-innovator organisations were significantly influenced by the verbalisation process through business partners. The greatest progress toward upper maturity levels were detected when internal factors strongly predominated over external factors. The developed methodology shows new approaches for cellular automata usage in the study of organisational systems. Key words: small organization, cellular automata, electronic commerce, innovation diffusionČlanek opisuje simulacijo elektronskega poslovanja v malih organizacijah s pomočjo celičnih avtomatov. Model in metoda sta verificirana na zgodovinskih podatkih. Namen raziskave je bil preučevanje dolgoročnih vplivov na elektronsko poslovanje, ki so posledica karakteristik organizacij. Definiranih je pet stopenj zrelosti v elektronskem poslovanju. Raziskava je potrdila, da je najpomembnejši dejavnik na širjenje elektronskega poslovanja „podpora vodstva”. Na dinamiko uvajanja in uporabe elektronskega poslovanja v organizacijah, ki niso inovatorji, pomembno vpliva proces verbalizacije. Največji napredek v stopnji zrelosti elektronskega poslovanja v malih organizacijah je bil dosežen pri dominantnejšem vplivu notranjih dejavnikov pred zunanjimi. Razvita metoda je pokazala nov pristop k uporabi celičnih avtomatov za preučevanje organizacijskih sistemov. Ključne besede: mala organizacija, celični avtomat, elektronsko poslovanje, širjenje inovacij

UTJECAJ PANDEMIJE COVID-19 NA ONLINE PRODAJU IZ PERSPEKTIVE HRVATSKIH POTROŠAČA I PRODAVAČA

The popularity of online sales is growing and it is becoming an unavoidable part of people’s lives. The process of accepting this form of sales and its development was accelerated by the Covid-19 pandemic, which caused the closure of physical stores, so people were forced to buy products and to use services online. Conducted desk research enabled collection of secondary data sources, based on which (i) a theoretical framework of paper was created; (ii) research objectives and questions were set; (iii) instruments for collecting primary data were created. The main objective of this paper is to determine the impact of the Covid-19 pandemic on e-commerce. Firstly, from a consumers point of view, who had to adapt to the new situation and start buying products and services online, and secondly, from the sellers’ perspective, who had to quickly adapt to new business conditions and shift their focus from physical to online sales. The paper provides an insight into the results of primary data collected by quantitative descriptive research using questionnaires as a collection instrument. Research results show whether there has been a change in consumer buying habits during the pandemic, and what adjustment has been represented by the sellers to meet volatile consumers needs during the pandemic.Prodaja putem interneta danas je sve popularnija i postaje nezaobilazan dio ljudskih života. Proces prihvaćanja ovog oblika prodaje i njezin razvoj ubrzala je pandemija Covid-19 koja je uzrokovala zatvaranje fizičkih prodavaonica, stoga su ljudi bili primorani kupovati proizvode i koristiti usluge putem interneta. Provedeno istraživanje za stolom omogućilo je prikupljanje sekundarnih izvora podataka na temelju kojih je (i) kreiran teorijski okvir rada; (ii) su postavljeni istraživački ciljevi i pitanja; (iii) su kreirani instrumenti prikupljanja primarnih podataka. Glavni cilj ovog rada je utvrditi utjecaj pandemije Covid-19 na e-trgovinu. Prvo, sa stajališta potrošača koji su se morali prilagoditi novonastaloj situaciji i početi kupovati proizvode i usluge putem interneta, i drugo, iz perspektive prodavača koji su se morali brzo prilagoditi novim uvjetima poslovanja i preusmjeriti fokus s fizičke na online prodaju. Rad daje uvid u rezultate primarnih podataka prikupljenih kvantitativnim opisnim istraživanjima pomoću anketnih upitnika kao instrumenta prikupljanja. Rezultati provedenih istraživanja pokazuju utjecaj pandemije na moguće promjene u kupovnim navikama potrošača te kakvu su prilagodbu prodavači izvršili kako bi tijekom pandemije zadovoljili potrebe potrošača

Surrogate Model Applied for Analysis of Uncertain Parameters in Turbulent Mixing Flows

The water mixing experiment in the Generic Mixing Experiment (GEMIX) facility performed at the Paul Scherrer Institute is used as a benchmark case to investigate the influence of the main uncertain parameters on the turbulent mixing under isokinetic flow conditions. The benchmark experiment features two horizontal water streams with the same inlet velocity that merge together to form a mixing flow inside the larger horizontal square channel. The turbulence intensity and the velocity profile at the inlet were used as the main uncertain input parameters. The selected set of computational fluid dynamics (CFD) simulations based on different combinations of values for uncertain parameters has been performed with the code NEPTUNE_CFD that solves the Reynolds Averaged Navier Stokes (RANS) equations with the k-ε turbulence model. To investigate the influence of the uncertain parameters over a wide range of values, the surrogate model called optimal statistical estimator (OSE) was used to generate the response surface of the results. It has been demonstrated that the OSE method can be successfully applied to build the response surface from a limited set of simulation points. For the two-parameter problem of the current study, only a few CFD simulation points are found sufficient to construct the quality response surface