Unit Element Research Articles

The Effect of Post-Weld Heat Treatment Temperature on the Structure and Hardness of Joints Made in Steel 10CrMoVNb9-1

The article discusses the effect of annealing temperature applied during heat treatment as well as the suitability of preheating before the welding of butt joints in pipes (having a diameter of 33.7 mm and a wall thickness of 4.5 mm) made of steel X10CrMoVNb9-1 (P91). In the article, the structure and properties of a joint subjected to heat treatment performed in accordance with manufacturing standards concerning power unit elements are compared with those of a joint not subjected to heat treatment. The welding process discussed in the paper was based on the TIG method and involved the use of filler metal Thermanit MTS 3 (W Cr Mo 91). The material of steel X10CrMoVNb9-1 after welding and not subjected to heat treatment is both very hard and brittle. Because of the fact that the power engineering steel of the above-presented characteristics cannot be exposed to the effect of a high-pressure and high-temperature medium (due to possible crack formation), the welding of such steel should be followed by appropriate post-weld heat treatment.

Scientific method of creation of ecologically clean capillary-porous systems of cooling of power equipment elements of power plants on the example of gas turbines

The novelty of the work is the development and research of a new highly accelerated capillary-porous cooling system for elements of gas turbine units, operating in the field of mass and capillary forces. Original models were created and a mechanism for the heat and mass transfer process in a capillary-porous cooling system was developed. First, equations were obtained for calculating the limiting heat fluxes and stresses for a poorly heat-conducting capillary-porous structure. Experimental setups and research methods using various porous structures have been developed. The experimental data for the vaporization processes in the studied porous system with boiling in a larger volume, thin-film evaporators and heat pipes is generalized. Newly developed systems make it possible to achieve savings in fuel, air, water and heat, whilst increasing the reliability of cooling and fire safety of the equipment concerned, as well as to obtain great economic and social effects in the field of ecology and health and safety.

The number of t-norms on some special lattices

We estimate the number of triangular norms on some classes of finite lattices. One of them is obtained from two chains by identifying their zero elements, unit elements and an atom. Another one is the set of the dual lattices of the previous one. The obtained formulas involve the number of triangular norms on the corresponding chains. We derive several properties of a triangular norm for this kind of lattices, that enable us to obtain better estimates. Moreover, we obtain the number of t-norms in another class of lattices, which includes the so-called Chinese lantern. Finally, we estimate the number of Archimedean t-norms and divisible t-norms on these lattices.

Optimization and Experimental Validation of a Modular Thermoelectric Heat Pump System for a Premature Baby Incubator

In this paper, a modular thermoelectric heat pump system (MTEHPS)-driven premature baby incubator is optimized, constructed and tested. The input parameters used in the optimization were experimentally determined from a commercial resistance incubator. In the theoretical part, mathematical modeling of the MTEHPS including a thermoelectric cooler module, heatsinks and fans for premature infant incubators has been created by using the basic laws of physics. Then, in order to improve the MTEHPS, two-step limited optimization was performed using the volume obtained by removing the control unit and heating element of the commercial incubator. In the first optimization step, the optimum geometric configurations of the heatsinks were determined based on the fin thickness and spacing to maximize the heat transfer rate for the limited volume. In the second step, using the optimum heatsink parameters as input, the total MTEHPS was optimized for the maximum coefficient of performance (COPheating) around the maximum heating power by using dimensional analysis method with developed MATLABR software, and optimum parameters of the system were determined. For the experimental part of the study, the MTEHPS was manufactured based on thermal and hydraulic parameters obtained as a result of the optimization and tested for thermal and electrical output parameters during steady-state operation of the incubator for a hood temperature of 36°C and ambient temperature of 25°C. It is found that the output parameters obtained from the optimization are in good agreement with the experimentally measured values. With an optimized MTEHPS, a COPheating of around 1.4 is reached, and the proposed system is economically feasible.

Equivalent circuit model for analysis of frequency selective surfaces with ring and double concentric ring apertures

In this study, the authors present two new proposals for representation by the equivalent circuit model for aperture-type circular ring geometries, not yet studied in the literature. The study consists of the frequency response representation of frequency selective surfaces (FSSs) formed by circular ring aperture and concentric circular ring apertures. At first, the authors performed an equivalent circuit analysis for a single cell formed by a single circular ring. Then, they extend the analysis to concentric circular rings, which when used as FSS unit elements, present two passband responses. They compare results of the proposed method with results obtained with the commercial software ANSYS HFSS, showing a good agreement between the results. They built four prototypes and compared measured results with simulated results obtained with the suggested method and it completes the proposed equivalent circuit validation.

Hepcidin-to-Ferritin Ratio Is Decreased in Astrocytes With Extracellular Alpha-Synuclein and Iron Exposure.

Astrocytes are the most abundant glial cells in the central nervous system (CNS). As indispensable elements of the neurovascular unit, they are involved in the inflammatory response and disease-associated processes. Alpha-synuclein (α-syn) is released into the extracellular space by neurons and can be internalized by adjacent astrocytes, which activates glial cells to induce neuroinflammation. We were interested in whether astrocyte-mediated neuroinflammation is modulated by intracellular iron status and extracellular α-syn. Our results showed that recombinant α-syn (1 μg/ml and 5 μg/ml) treatment for 24 h did not affect the expression of the iron transporters divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1), nor those of iron regulatory protein (IRP) 1 or IRP2. Several proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 exhibited up-regulated mRNA levels in 5 μg/ml α-syn-treated astrocytes. TNF-α release was increased, indicating that inflammatory responses were triggered in these cells. Pretreatment with the iron-overload reagent ferric ammonium citrate (FAC, 100 μmol/L) for 24 h had no effects on mRNA levels and release of proinflammatory cytokines. Inflammatory responses triggered by α-syn were not affected by iron overload. The iron chelator desferrioxamine (DFO, 100 μmol/L) exerted suppressive effects on TNF-α mRNA levels, although no change was observed for TNF-α release. Hepcidin mRNA levels were down-regulated significantly in astrocytes co-treated with FAC and α-syn, although independent treatment with either FAC or α-syn did not alter hepcidin levels. In contrast, hepcidin mRNA levels were up-regulated in DFO and α-syn co-treated cells. As expected, ferritin protein levels were up-regulated or down-regulated with FAC or DFO treatment, respectively. Following the up-regulation of ferritin mediated by α-syn, hepcidin-to-ferritin levels were indicative of modulatory effects in α-syn-treated astrocytes with altered iron status. Therefore, we propose that the hepcidin-to-ferritin ratio is indicative of a detrimental response in primary cultured astrocytes experiencing iron and extracellular α-syn.

Regulation of the frictional characteristics disc brake

The article presents the results of an experimental study of the influence of external vibration disturbances on the working elements of the friction unit, which simulate the power circuit of the disc brake: brake pad and brake disc. The studies were carried out on the original friction machine reproducing the interaction conditions of the disc brake elements on a scale of 1:100. Vibration impact on the working elements of the friction unit was carried out by means of a drive, which allowed to implement a sequence of power pulses in the frequency range 5–100 Hz. It is shown that due to the vibration disturbances of the working elements it is possible to influence the friction characteristics within 20–25%.

When the Range of Every Orthomorphism is an Order Ideal

In this paper, it is proven that a uniformly complete vector lattice A is normal if and only if the range of every extended orthomorphism in A is an order ideal of A. As an application, it is shown that a vector lattice A is hyper-Archimedean if and only if the range of every extended orthomorphism in A is a uniformly closed order ideal of A. Moreover, a complete description of Archimedean f-algebras with unit elements such that the range of every orthomorphism is an order ideal is given in terms of order, algebraic and topological properties.

Classification of two-dimensional left(right) unital algebras over algebraically closed fields and ℝ

In this paper we describe all left, right unital and unital algebra structures on two-dimensional vector space over any algebraically closed field and ℝ. We tabulate the algebras and provide their unit elements.

Analytic method of structural analysis of modular buildings

The paper presents an analytical method of modular buildings calculation. It focuses upon basic design assumptions that are accepted for modular buildings calculation. The authors introduce their classification of loads and impacts, which are basic for modular buildings. They also describe a method of determining inertial forces from seismic action designed on the basis of a cantilever analytical model. Analytical and numerical methods for determining the forces in the elements of modular units are further compared. It is revealed that the analytical method strongly agrees with FEM (that is the finite elements method) with the error being 2-6%. The analytical method is sufficiently accurate for engineering calculations.

ON THE USE OF TERMS «RING» AND «PAD» FOR THE IDENTIFICATION OF SEPARATE KNOTS OF STRUCTURES IN THE OIL AND GAS INDUSTRY

Scientific knowledge and the emergence of new concepts are components of the development of the potential of science and technology. Systematization and assignment of a clear function to each term are important tasks in conducting any scientific research and study of the material. Strengthening the holes in the pressure vessels and strengthening the branches of pipeline T-joints with reinforcing elements are similar processes in their technological principle. The work analyzes such generally accepted terms of these reinforcing elements as: «patch ring» and «reinforcement ring» related to pressure vessels and «reinforcement pad», «pad», «strengthening pad» and «collar» relating to the pipeline transportation system. These parts are similar in design, assembly technology, and welding and technical purpose. In regulatory documents and scientific literature, these terms often replace each other. The analysis was carried out not only for domestic sources but also for English regulatory documents. After analyzing various sources, it was found out that the term «ring» was entrenched behind the branch of vessels and devices operating under pressure, and «pad» - in the pipeline transportation system. In the scientific community, there is no clear answer to the question of why such similar reinforcing elements of units for the technological process of welding and assembling have adopted different names. The analysis of terminology showed that the term «patch ring» has a clear fixed content, most accurately describes the purpose of the reinforcing element and its geometric shape, meets all the norms and rules of the Russian language and has all the necessary and sufficient features.

On clean and regular elements of near-ring of skew polynomials

In this paper, we are interested to investigate some properties of the zero-symmetric near-ring of skew polynomials We first show that if R is an -compatible ring and Nil(R) is a locally nilpotent ideal of R, then the set of all nilpotent elements of the near-ring forms an ideal and Then we characterize the unit elements, the regular elements, the π-regular elements and the clean elements of where the base ring R is a semicommutative ring with Also, we prove that the set of all π-regular elements of forms a semigroup. These results are somewhat surprising since, in contrast to the skew polynomial ring case, the near-ring of skew polynomials has substitution for its “multiplication” operation.

Morphological structure of the aortic wall in three Delphinid species with shallow or intermediate diving habits: Evidence for diving adaptation.

Some modifications in the vascular system of marine mammals provide adaptive advantages for diving. This study analyses the organisation of the aortic wall in dolphins, observing artery changes in volume and blood pressure for diving behaviour. Samples of three aortic segments (ascending, thoracic and abdominal) of three dolphin species were processed for histological and morphometric studies. The three dolphin species used, striped dolphin (Stenella coeruleoalba), Atlantic spotted dolphin (Stenella frontalis) and common dolphin (Delphinus delphis), have shallow or intermediate diving habits. Our results indicated that the components of the aortic wall of the dolphins had different dispositions in the three selected segments. The aortic wall decreased in thickness along its length due to a loss of the lamellar units in the tunica media and a thinning of the main elements of the lamellar units along the artery. The life stage had little influence on the thickness of the aortic wall except for the ascending aorta. The weight, body length, species or sex of the specimen did not significantly influence the thickness of the wall or the lamellar units. In summary, the histological and morphometric aortic structure in dolphins, in relation to the studied parameters, seems to be similar to that previously described of terrestrial mammals such as pigs, except for a larger difference in the proportion of lamellar units between the ascending and thoracic segments.

Abstract TP468: Differential Effect of Ischemia and Thrombin Mediated Toxicity on Neurovascular Unit

Objectives: Brain is a complex structure during ischemia along with neurons; components of vascular unit astrocytes, pericytes and endothelial cells play a major role in hypoxic and blood brain barrier leakage mediated injury. Thrombin acts via protease activated receptor-1 (PAR-1) and leads to neuronal survival or death, PAR-1 knockout cells survive ischemia. We hypothesize that different elements of the Brain vascular unit play different roles in responding to injury. The present study aimed to establish a correlation between astrocytes, pericytes and endothelial cells vulnerability via OGD model of ischemia and Thrombin mediated toxicity. Methods: Using highly reproducible oxygen glucose deprivation (OGD) model Primary cultured cells were exposed to OGD for various durations and Thombin doses to determine the optimum time point for 80 % cell death or cell viability measured using LDH release assay MTT assay. LD50 dose of OGD and Thrombin was used to determine the effect of various drugs mediating PAR-1 receptor pathway Results: The viability assay using MTT showed that the three elements of vascular unit respond differentially to longer durations of ischemia, with pericytes being the most vulnerable, followed by endothelial cells, followed by astrocytes. Our thrombin dose effect shows that Pericytes and endothelial respond to thrombin similarly whereas, astrocytes on lower concentration proliferate, but don’t survive the higher concentrations. Conclusion: An exciting, novel finding in our data is that different elements of the vascular unit—astrocytes, pericytes and endothelial cells—all exhibit effect of ischemia and reperfusion at different time scales. Up until recently, studies of neuroprotection addressed the brain as a homogenous unit, with the tacit assumption that all elements responded similarly. Our data on astrocytes, endothelial cells and pericytes—allows more focused investigation.

A generalization of semiclean rings

Ye defined a ring to be semiclean if every element of it can be written as a sum of a unit element and a periodic element. In this paper we generalize the notion of a semiclean ring to an almost semiclean ring. A ring R is said to be almost semiclean if each element is a sum of a regular element and a periodic element. We discuss some basic properties of almost semiclean rings. For example, R is almost semiclean if and only if the polynomial ring over R is almost semiclean. We also discuss when the idealization is almost semiclean. Finally, we give examples which distinguish almost semiclean rings from other classes of rings.Communicated by Silvana Bazzoni

Gaseous Vapor Emission (GVE) Technique for Detection of Petrol Adulteration at Point of Sale (POS) Terminals

A one-dimensional mathematical modelling and simulation of the riser reactor in a fluid catalytic cracking unit was presented in this work. The seemingly increasing demand for lighter fractions of petroleum as source of energy has necessitated that the fluid catalytic cracking (FCC) unit be modelled with greater precision and accuracy. A more accurate model of the riser reactor that is one of the primary functional elements of the FCC unit is important in improving the performance of the entire unit. Salient issues in the presented model were the four-lump kinetic model for the cracking mechanism, slip factor consideration between the phases, exponential catalyst activity deactivation model and the instantaneous estimation of the temperature dependent specific heat capacities of reacting species during the reaction. The model exhibited the behaviour expected of a riser reactor based on comparison with some industrial plant data and previous simulations. Simulation results showed that increase in the catalyst to oil ratio (COR) led to increase in gasoline yield only to a particular limit beyond which the yield began to decline. Presented results showed reasonable set of parameters for operating the riser which could lead to better yield. Keywords: One-dimensional (1-D), FCC, riser, hydrodynamic, lump kinetic, modelling, simulation.

Типология и синтаксономический состав территориальных единиц растительности: новый подход на примере изучения арктических маршей

Типология и синтаксономический состав территориальных единиц растительности: новый подход на примере изучения арктических маршей

ПЕРЕКЛАД ФРАЗЕОЛОГІЧНИХ ОДИНИЦЬ У ЗАГОЛОВКАХ ПУБЛІЦИСТИЧНОГО СТИЛЮ (НА ПРИКЛАДІ «НЬЮ-ЙОРК ТАЙМС»)

У статті проаналізовано наукову літературу з даної теми та порівняно особливості використання фразеологічних одиниць у заголовках. Виділено основні типи функціонально-стилістичних груп фразеологічних одиниць. Дослідження показало, що основними типами трансформації фразеологічних одиниць є найпростіші зміни елементів синтаксичних одиниць, які є результатом їх перестановки, заміщення, додавання та скорочення. Аналіз наукових джерел показав, що поняття «фразеологічна одиниця» розглядалося багатьма вченими і трактується як стійка фраза або вираз, що характеризується відтворюваністю, цілісністю значення, стійкістю поєднання слів та прихованим значенням. В статті авторами виділено основні типи функціонально-стилістичних груп фразеологічних одиниць. Суть семантичної трансформації фразеологізму полягає у введенні нових семантичних відтінків або грі слів у фразеологізми. Основні типи аналітичної трансформації можна визначити наступним чином: синтаксичні; лексичний; забруднення. Крім того, фразеологізми висвітлюють проблеми в більш м’якому світлі, забарвлюючи назву журналістського тексту, тим самим привертаючи до нього увагу. Аналіз заголовків у «The New York Times» показав, що в сучасній журналістській практиці використання фразеологічних одиниць є популярним метод просування тексту. Доведено, що автори у своїх роботах використовують майже всі стилі та типи фразеологічних одиниць, але найчастіше в українській мові вживаються розмовний стиль та жаргонні слова, рідше педантичний стиль та практично відсутні міжстильові фразеологізми, а в англійській мові більшість часто розмовний і педантичний стилі, рідше використовується розмовний. Фразеологічні одиниці складають ядро фразеологічного фундаменту будь-якої мови, містять історичну та культурну інформацію та відображають динаміку розвитку мовлення.

Antifriction powder bronzes with mechanically alloyed copper-based granules

New antifriction composite materials of matrix-filled type based on tin bronze powder for heavily loaded elements of friction units are presented. As their load-bearing structural component heat – and wear-resistant fillers in the form of copper-based granules with the initial composition Cu-5% Al-2% C-2% MoS2 are used, obtained in the course of the reactionary mechanical alloying of copper powder in the air of attritor by aluminum and lubricating additives in the form of graphite and molybdenum disulfide. Dynamically thermostable particles in the form of γ–Al2O3 oxides of nanodispersed level, mechanochemically synthesized in the attritor, are evenly distributed in copper-based cold-hardened granules and provide them with a high temperature of softening - up to 08…0.9 of the melting temperature of copper. The addition of such granules to powder bronze with 5 wt% tin allowed to obtain antifriction composite materials, which in terms of mechanical and tribotechnical properties significantly exceed the standard antifriction tin and aluminum bronzes and, in particular, bronze EN CuSn8 and EN CuAl10Ni5Fe4.

Notatki językowe: o jocie i komie

In Norwid’s writings, the nouns koma [comma] and jota [iota] that literally mean respectively: ‘comma’ and ‘the ninth letter of the Greek alphabet’ or ‘the Polish letter and consonant j’, in the vast majority of cases have secondary, figurative meanings – in particular, when they are elements of phraseological units, but also in some other contexts they usually refer to some small elements of a text. It is symptomatic that a large part of Norwid’s usages more or less directly refer to the well-known biblical quotation from the Gospel of Matthew, which in King James Version reads: “For verily I say unto you, till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.” Norwid’s use of comma and iota analysed in this article indirectly confirms the importance that the poet attached not only to the graphic layout and punctuation, or more generally to the formal aspects of the texts, but also to their proper, profound understanding.