Method of forming shrink-fit compression seal

A method for making a glass-to-metal seal is described. A domed metal enclosure having a machined seal ring is fitted to a glass post machined to a slight taper and to a desired surface finish. The metal part is then heated by induction in a vacuum. As the metal part heats and expands relative to the glass post, the metal seal ring, possessing a higher coefficient of expansion than the glass post, slides down the tapered post. Upon cooling, the seal ring crushes against the glass post forming the seal. The method results in a glass-to-metal seal possessing extremely good leak resistance, while the parts are kept clean and free of the contaminants

Three-dimensional time domain model of lightning including corona effects

A new 3-D lightning model that incorporates the effect of corona is described for the first time. The new model is based on a Thin Wire Time Domain Lightning (TWTDL) Code developed previously. The TWTDL Code was verified during the 1985 and 1986 lightning seasons by the measurements conducted at the 553 m CN Tower in Toronto, Ontario. The inclusion of corona in the TWTDL code allowed study of the corona effects on the lightning current parameters and the associated electric field parameters

Efficiency of size-dependent particle separation by pinched flow fractionation

Pinched flow fractionation is shown to be an efficient and selective way to quickly separate particles by size in a very polydisperse semi-concentrated suspension. In an effort to optimize the method, we discuss the quantitative influence of the pinching intensity in the balance between the requirements of selectivity and minimal dilution.Comment: 5 pages, 3 figures, accepted in Microfluidics and Nanofluidic

Lethal alleles in evolution

Letalni aleli uzrokuju smrt organizma koji ih nosi, no ponekad smrt nije trenutačna - mogu proći i godine prije nego smrt nastupi, ovisno o utjecaju letalnog gena na organizam odnosno njegovoj funkciji. Ako mutacija završava trenutnom smrću, tada je zahvaćeni gen esencijalan za rast, razvoj i preživljavanje organizma. Prvi koji je primijetio letalne alele 1905. godine bio je Lucien Cuénot, a nakon njega su mnogi istraživači započeli rad u tom području. Letalni aleli ne izazivaju smrt uvijek u istim uvjetima, pa stoga postoji nekoliko vrsta letalnih alela (dominantni, recesivni, subletalni, uvjetni i sintetički letalni aleli). Najopsežnija istraživanja broja i učinka letalnih alela su napravljena u prirodnim populacijama vrsta Drosophila melanogaster M. i Mus musculus L., te u novije vrijeme u vrsta riba Lucania goodei G. i Danio rerio H. Usporedbama rezultata dobivenih na tim vrstama dobivene su bitne činjenice o evoluciji letalnih alela, no još je uvijek vrlo teško sa sigurnošću zaključiti što sve utječe na njihovu distribuciju u različitim populacijama. Otkriven je i učinak nekih letalnih alela na spolne kromosome koji uzrokuju brojne bolesti i mutacije. Saznanja o učestalosti letalnih alela u populaciji su važna za razumijevanje populacijske genetike i evolucije. Letalne mutacije mogu objasniti mnoge fenomene u evolucijskoj biologiji, poput usrođenosti i njezinog utjecaja na populacije, ili pak uzroka nekih nasljednih bolesti koje imaju letalan učinak, a povezane su s letalnim alelima. Stoga je vrlo važno nastaviti s istraživanjem letalnih alela kako bi se eventualno otkrio njihov utjecaj na razvoj i život jedinki.Lethal alleles cause the death of an organism that carry them, but sometimes, death is not immediate - it may take years before death occures, depending on the function of a lethal gene and its impact on an organism. If the mutation results in lethality then the affected gene is essential for growth, development, and survival of an organism. Lucien Cuénot was the first researcher who noticed the effects of lethal genes on mice in 1905, thereafter many researchers started to explore lethal genes. There are several types of lethal alleles due to the fact that they cause death under the different conditions (dominant, recessive, sublethal, conditionally lethal and synthetic lethal alleles). The most aboundant research of the number and the effect of lethal alleles was done on Drosophila melanogaster M. and Mus musculus L., as well as on fish species Lucania goodei G. and Danio rerio H. Comparisons of the data obtained on the different species have provided important conceptions about evolution of lethal alleles, neverthelles the mechanisms of their distribution in different wild populations are still vaguely understood. Effect of some lethal alleles on sex chromosomes, which causes numerous diseases and mutations, was also discovered. Informations about the frequency of lethal alleles in populations are important for understanding population genetics and evolution. Lethal mutations could explain a number of phenomens in evolutionary biology, such as inbreeding and it`s effect on populations. Also, determination of frequency of lethal alleles would enable certain lethal alleles to be correlated with some common hereditary diseases which have a lethal effect. It is therefore very important to continue researching in the area of lethal alleles, in order to get a better insight in their impact on development and life of organisms

Tournament decision theory

The dispute in philosophical decision theory between causalists and evidentialists remains unsettled. Many are attracted to the causal view’s endorsement of a species of dominance reasoning, and to the intuitive verdicts it gets on a range of cases with the structure of the infamous Newcomb’s Problem. But it also faces a rising wave of purported counterexamples and theoretical challenges. In this paper I will describe a novel decision theory which saves what is appealing about the causal view while avoiding its most worrying objections, and which promises to generalize to solve a set of related problems in other normative domains

Market reactions to unexpected political changes: evidence from advance emerging markets

The main aim of this article is to assess the influence of change in Prime Minister on Polish stock market. Prime Minister Szydło resigned shortly after she survived the second vote of no confidence on December 8, 2017, and was replaced by Morawiecki, the Vice-Prime Minister and Minister of Finance, and a former CEO of a large bank.1 Considering the aforementioned context, this study tests four hypotheses regarding the market reaction in terms of companies’ shareholder structure. An event study analysis was performed to calculate cumulative abnormal returns, and regression models were estimated to test the hypotheses. The author finds significant negative price changes only for stateowned enterprises (SOEs) both directly and indirectly controlled by the government. I assume that this reaction in the case of SOEs was caused by the uncertainty related to the likely changes in the management

Pairwise hydrodynamic interactions and diffusion in a vesicle suspension

The hydrodynamic interaction of two deformable vesicles in shear flow induces a net displacement, in most cases an increase of their distance in the transverse direction. The statistical average of these interactions leads to shear-induced diffusion in the suspension, both at the level of individual particles which experience a random walk made of successive interactions, and at the level of suspension where a non-linear down-gradient diffusion takes place, an important ingredient in the structuring of suspension flows. We make an experimental and computational study of the interaction of a pair of lipid vesicles in shear flow by varying physical parameters, and investigate the decay of the net lateral displacement with the distance between the streamlines on which the vesicles are initially located. This decay and its dependency upon vesicle properties can be accounted for by a simple model based on the well established law for the lateral drift of a vesicle in the vicinity of a wall. In the semi-dilute regime, a determination of self-diffusion coefficients is presented