The Finite Basis Problem for Kiselman Monoids

In an earlier paper, the second-named author has described the identities holding in the so-called Catalan monoids. Here we extend this description to a certain family of Hecke--Kiselman monoids including the Kiselman monoids $\mathcal{K}_n$. As a consequence, we conclude that the identities of $\mathcal{K}_n$ are nonfinitely based for every $n\ge 4$ and exhibit a finite identity basis for the identities of each of the monoids $\mathcal{K}_2$ and $\mathcal{K}_3$. In the third version a question left open in the initial submission has beed answered.Comment: 16 pages, 1 table, 1 figur

Dimensional analysis in the machining of housing components with cast holes

When cast housing components are machined, the displacement of the hole axis in reaming must be taken into account, because it produces pronounced nonuniformity of the margin. Means of reducing the machining error are analyzed. © 2013 Allerton Press, Inc

Secondary atomization of a biodiesel micro-emulsion fuel droplet colliding with a heated wall

Using high-speed video recording, we establish the following regimes of hydrodynami

Закономерности изменения адсорбционных свойств глин, активированных давлением и ионами железа

The purpose of the work is to consider the patterns of adsorption of water vapor by clay soils that have been treated with pressure and saturated with iron ions, and also to study the processes of adsorption and desorption of Fe3+ ions by bentonite and kaolin clays. The study of changes in the adsorption properties of clay soils is necessary to understand the processes occurring in soils, both in natural and anthropogenic conditions, especially in the case of soil contamination. As a result of the experiment, it was found that the adsorption capacity of clays in relation to water vapor increases when they are treated with pressure. When clay is treated with pressure and subsequently saturated with iron ions in bentonite clay, the adsorption activity decreases in the range of 0-150 MPa, at higher pressures it changes irregularly. In kaolin, adsorption increases at pressures up to 200 MPa, but it decreases at pressures from 200 to 800 MPa.Цель работы: рассмотреть закономерности адсорбции водяного пара глинистыми грунтами, которые были обработаны под разными давлениями и насыщены ионами железа, а также изучить процессы адсорбции и десорбции ионов Fe3+ бентонитовой и каолиновой глинами. Изучение изменений адсорбционных свойств глинистых грунтов необходимо для понимания процессов, происходящих в грунтах как в природных, так и в антропогенных условиях, особенно в случае загрязнения грунтов. В результате эксперимента было установлено, что адсорбционная способность глин по отношению к водяному пару возрастает при обработке их давлением. При обработке глин давлением и при последующем насыщении их ионами железа в бентонитовой глине адсорбционная активность снижается в диапазоне 0–150 МПа, при более высоких давлениях изменяется незакономерно. В каолине происходит рост адсорбции при давлениях до 200 МПа, но она уменьшается при давлениях от 200 до 800 МПа

Study of the activity of bifunctional catalyzers on the transformation of n-hexane

The production of various motor fuels is carried out by processing light fractions of oil with an initial temperature of boiling to 350°С. The current trend shows that oil in new fi elds has more weight than before. New oil reservoirs are deeper with a greater proportion of dark fraction with a boiling point of 350°С. This situation stimulates to fi nd new ways of increasing the processing depth light fractions for synthesis target product. One of the main solution path for the problem is creation of new catalytic systems or modernization of existing ones. Motor fuels must meet the necessary operational and environmental characteristics, which is determined by their chemical composition. This article is devoted to the study of bifunctional catalyzers for the conversion of n-hexane. High molecular zeolite CVM (ZSM-5) was used as a carrier, which has functionality due to the presence of various active centers. Platinum (Pt/CVM), praseodymium (Pr/CVM) were also applied to the carrier, and praseodymium and platinum (Pt,Pr/CVM) were successively applied by impregnation. Normal hexane was used as a raw material. The choice of this raw material is associated with the ability to aromatization reaction, as well as the presence of n-hexane in the raw materials of the process of obtaining motor fuels-catalytic reforming. As a result of the transformation of raw materials, liquid fuel of multicomponent composition with the number of carbon atoms in the chain from 3 to 14, as well as gases containing C1 – C5 hydrocarbons, was obtained. When n-hexane is converted on the catalyzers under study, both the octane number and the content of aromatic hydrocarbons increase with increasing temperature. It has been found that when the process is carried out at a temperature of 450°C, the highest yield of the catalysate is (33.8% by weight.) on a Pt,Pr/CVM catalyzer. With an increase in temperature, the yield of benzene increases. Minimum benzene yield (0.6 wt. %) is achieved at 450°C marked by a bimetallic catalyzer, which corresponds to the EURO-5 gasoline standard. The highest degree of conversion was observed during the conversion of n-hexane on the Pt,Pr/CMC catalytic system at a temperature of 450° C, which was (97%)

Multicriteria verbal analysis for the decision of construction problems

The paper aims to analyse the construction contracts and to determine their effectiveness by verbal methods. Contractors of international construction projects are often faced with complicated situations working in the conditions of uncertainty in construction. One of the potential risk factors is associated with the requirements of contract conditions. A simple quantitative method for evaluating the requirements defined in specifications of the contract is presented. One of the major aspects is project or contract management. Project developers need various models of managing large and complex projects. The suggested method for evaluating contract effectiveness may be widely applied at one of the stages of project management. A case study of practical use of verbal methods is presented. Santrauka Siekiama išanalizuoti statybos sutartis ir nustatyti jų efektyvumą daugiatiksliu verbaliniu metodu. Tarptautiniuose statybos projektuose rangovai dažnai susiduria su sudėtingomis situacijomis ir darbo sąlygų neapibrėžtumais. Tai yra pagrindinis rizikos veiksnys sudarant statybos rangos sutartis. Pateiktas metodas įvertina sutarties specifikacijų reikalavimus. Vienas iš svarbiausių aspektų yra projekto ar sutarties valdymas, todėl projekto valdytojams reikalingi įvairūs modeliai dideliems ir sudėtingiems projektas kontroliuoti. Siūlomas sutarties efektyvumo įvertinimo metodas gali būti plačiai taikomas visam projektui ar atskirai jo daliai. Straipsnyje yra pateiktas pavyzdys taikant daugiatikslį verbalinį metodą. First published online: 21 Oct 2010 Reikšminiai žodžiai: verbalinės analizės metodai, ekspertinės sistemos, sprendimų priėmimas, daugelio kriterijų pasirinkimo problema, kriterijų pirmenybės nepriklausomybės, kontrolės nuoseklumas

The relationship of fracture toughness coefficients and geophysical characteristics of rocks of hydrocarbon deposits

This paper contains the results of laboratory tests to determine the fracture toughness coefficient KIC of rocks for terrigenous and carbonate objects by three methods. The tests were carried out by different methods due to the lack of a standard method for determining the fracture toughness characteristics of rocks in Russia. We used the following methods for determining the KIC coefficient: the extension of core specimens with an annular fracture, the action of a concentrated load on a beam specimen with a fracture and the method of bending semi-circular samples with a fracture according to ISRM recommendations. The paper presents the relationship of the fracture toughness coefficients with the P-wave velocity and porosity. The obtained dependencies characterize the general trend of changing for the studied parameter and can be used in the design of hydraulic fracturing in the fields for which tests were conducted

The age of mineralization of Mayskoe gold ore deposit (Central Chukotka): results of Re-Os isotopic dating

The article presents the results of the sulfide mineralization dating of the Mayskoe gold ore deposit using the Re-Os isotope system and isochron age estimation method of the main sulfide minerals: arsenopyrite, pyrite, and antimonite. The complex multistage formation of the studied sulfides, as well as the close intergrowths of genetically different mineral phases, did not allow obtaining a single rhenium-osmium isochron corresponding to the formation time of sulfide mineralization. Isochrones for single minerals, collected from each sulfide sample, turned out to be the result of isotopically distinct components mixture (radiogenic crustal and non-radiogenic mantle) and do not make sense from the geochronological point of view. In terms of geology, the most significant result of the study is an age estimation of 128.8 ± 4.4 Ma, obtained for the sulfide mineralization of Mayskoe deposit using Re-Os isotope dating of single fractions of pyrite and antimonite of the ore mineralization stage. While arsenopyrite is most closely associated with gold mineralization, one of the arsenopyrite varieties corrodes framboidal pyrite of the pre-ore stage, has a maximum of the crust component in the osmium isotopic composition and forms a mixing line in the isochron diagram with an apparent formation age of 458 ± 18 Ma. The initial osmium isotopic composition of the studied sulfides indicates a mixed mantle-crust source of sulfide mineralization. The issue of simultaneous ore genesis and granitoid magmatism in the Mayskoe deposit remained unresolved (the age of granitoids according to the U-Pb zircon system is 108 Ma). However, a possible solution could be the further determination of the Re-Os isochron age of the ore mineralization sulphides from the single paragenesis of a specific sample containing both arsenopyrite and pyrite (+ antimonite) with gold