Computer simulations in the ventilation network of the Vulcan Mine

Maintaining safety and health conditions underground, especially where potentially explosive atmospheres are possible, depends mainly on how the ventilation system is built, applied and operated in the ventilation network. The ventilation networks of a mining unit for the exploitation of the useful mineral substance are mining works that aim to ensure optimal microclimate conditions in the underground. An ventilation network is built of nodes and branches, in order to establish its structure. In order to establish the optimal air flows at branch level, specialized programs are used, with the help of which the modeling, solving and optimization of the ventilation networks can be performed. Optimizing the management of the ventilation system involves in-depth and complex analyzes on the ventilation network that require a huge volume of data that can be processed only with the help of computing technology. The paper presents an analysis of the ventilation network of the Vulcan mine using the calculation technique to simulate situations that may occur in the ventilation system.

Serviceability of Post-fire RC Rafters with Openings of Different Sizes and Shapes

This study deals with the serviceability of reinforced concrete solid and perforated rafters with openings of different shapes and sizes based on an experimental study that includes 12 post-fire non-prismatic reinforced concrete beams (solid and perforated). Three groups were formed based on heating temperature (room temperature, 400 °C, and 700 °C), each group consisting of four rafters (solid, rafters with 6 and 8 trapezoidal openings, and rafter with eight circular openings) under static loading. A developed unified calculation technique for deflection and crack widths under static loading at the service stage has been provided, which comprises non-prismatic beams with or without opening exposed to flexure concentrated force. Two approaches were used to compute the deflection: The first attempt was conducted by using the moment of inertia for solid non-prismatic beam and reduced for those with openings by the ratio of residual rafter self-weight. The second was performed by using the moment of inertia of transformed cracked sections depending on the segmental rafter method. The crack width was determined using the ACI code's equation. The analytical and experimental results were evaluated and found to be in good agreement.

COMPUTER SIMULATION OF INTERACTIONS OF TETRATHIOPHENE MOLECULES

Надмолекулярная организация сопряженных полимеров сильно влияет на подвижность носителей заряда и, следовательно, на свойства производимых электронных устройств на их основе. Поэтому является важным научится строить вычислительные модели способные воспроизводить структуру таких полимеров с максимально возможной точностью. Одной из главных движущих сил процесса самосборки надмолекулярных структур в сопряженных полимерах является п - п взаимодействие. Его учет является достаточно трудной задачей, особенно при построении мезомасштабных моделей. В данной работе мы используем теорию функционала электронной плотности для отработки методики расчета сопряженных полимеров с учетом п - п взаимодействия. Были изучены геометрические характеристики пачек из четырех молекул тетратиофена. Выполненные расчеты показывают, что использование функционала M06-2X-D3 позволяет корректно моделировать взаимодействия молекул олиготиофенов и структуру образующихся агрегатов, в то время как полуэмпирические расчёты методом PM7 сопряженных полимеров пригодны лишь для быстрой предварительной оптимизации моделей. Разработанная методика расчетов имеет важное значение для параметризации мезомасштабных схем моделирования. The properties of the supramolecular organization of conjugated polymers strongly affect the mobility of charge carriers and, consequently, the properties of produced electronic devices based on them. Therefore, it is important to learn how to build computational models capable of reproducing the structure of such polymers with the highest possible accuracy. One of the main driving forces of the self-assembly of supramolecular structures in conjugated polymers is п-п interaction. Taking it into account is a rather difficult task, especially when constructing mesoscale models. In this work, we use the electron density functional theory to develop a methodology for calculating conjugated polymers taking into account п-п interaction. The geometric characteristics of stacks of four tetra thiophene molecules were studied. The performed calculations show that the use of the M06-2X-D3 functional makes it possible to correctly model the interactions of oligothiophene molecules and the structure of the resulting aggregates, while semiempirical calculations by the PM7 method of conjugated polymers are suitable only for rapid preliminary optimization of models. The tested calculation technique is of great importance for the parametrization of mesoscale modeling schemes. Keywords: organic solar cells, organic polymers, thiophenes, quantum chemical calculations, п-п stacking interaction.

ANALISIS MAQASID AL-TASARRUFAT AL-MALIYYAH MUHAMMAD AL-TAHIR IBN ASHUR TERHADAP AKAD AL-IJARAH AL-MUNTAHIYAH BI AL-TAMLIK (STUDI PADA PT. BRI SYARIAH KCP PONOROGO)

The writing aims: (1) find an assessment to measure the level of bank compliance with the contract al-Ijarah al-Muntahiya bi al-Tamlik (IMBT) based on maqasid al-tasarrufat al-maliyyah the idea of al-Tahir ibn 'Ashu r, (2) reveals the phenomenon of BRI Syariah KCP Ponorogo compliance with the IMBT contract. The research method used is a qualitative method with a case study type. The type of data in this research is qualitative data on the words and actions of the research subject. Data collection techniques used documentation and unstructured planned interviews. Technique of checking data through credibility test and dependability test. The data analysis technique used Miles and Huberman's analysis with data reduction, data presentation, and conclusion drawing. To make an assessment of the suitability of Islamic banks using the Sekaran method to operationalize maqasid al-tasarrufat al-maliyyah the idea of al-Tahir ibn 'Ashur into dimensions and elements. To develop measurement indicators using the DSN-MUI fatwa. Meanwhile, to obtain a score of compliance with Islamic banks using the balanced scorecard method calculation technique. The findings of this research are BRI Syariah KCP Ponorogo complies with the sharia provisions in the IMBT contract based on maqasid al-tasarrufat al-maliyyah ideas al-Tahir ibn 'Ashur. The level of compliance is 72.5% with the fulfillment of circulation goals of 70%, transparency 68.75%, strength of law 80%, preservation of 75%, and justice 68.75%. This study contributes to a qualitative assessment of sharia compliance based on maqasid al-tasarrufat al-maliyyah ideas al-Tahir ibn 'Ashur as a standard or parameter to assess adherence. Islamic banks in channeling IMBT financing.Penelitian ini bertujuan: (1) menemukan assesmen untuk mengukur tingkat kepatuhan bank terhadap akad al-Ijarah al-Muntahiya bi al-Tamlik (IMBT) berdasarkan maqasid al-tasarrufat al-maliyyah gagasan al-Tahir ibn ‘Ashur, (2) mengungkap fenomena kepatuhan BRI Syariah KCP Ponorogo terhadap akad IMBT. Metode penelitian yang digunakan adalah metode kualitatif dengan tipe studi kasus. Jenis data penelitian ini adalah data kualitatif kata-kata dan tindakan subjek penelitian. Teknik pengumpulan data menggunakan dokumentasi dan wawancara terencana tidak terstruktur. Teknik pemeriksaan data melalui uji kredibilitas dan uji dependibilitas. Teknik analisis data menggunakan analisis Miles dan Huberman dengan reduksi data, penyajian data, dan pengambilan kesimpulan. Untuk membuat assesmen kesesuaian bank syariah menggunakan metode Sekaran untuk mengoperasionalisasi maqasid al-tasarrufat al-maliyyah gagasan al-Tahir ibn ‘Ashur menjadi dimensi dan elemen. Untuk mengembangkan indikator pengukuran menggunakan fatwa DSN-MUI. Sedangkan untuk memperoleh skor kepatuhan bank syariah menggunakan Teknik perhitungan metode balanced scorecard. Temuan penelitian ini adalah BRI Syariah KCP Ponorogo patuh terhadap ketentuan syariah dalam akad IMBT berdasarkan maqasid al-tasarrufat al-maliyyah gagasan al-Tahir ibn ‘Ashur. Tingkat kepatuhannya sebesar 72.5% dengan pemenuhan tujuan sirkulasi 70%, transparansi 68.75%, kekuatan hukum 80%, preservasi 75%, dan keadilan 68.75%. Penelitian ini berkontribusi pada assesmen kepatuhan syariah secara kualitatif berdasarkan maqasid al-tasarrufat al-maliyyah gagasan al-Tahir ibn ‘Ashur sebagai standar atau parameter untuk menilai kepatuhan Bank syariah dalam menyalurkan pembiayaan IMBT.

Application of the Fractal Dimension Calculation Technique to Determine the Shape of Selected Monchepluton Intrusion Crystals (NE Fennoscandia)

Thirty-eight samples of minerals from Paleoproterozoic Layered PGE Intrusion Monchepluton, located in NE Fennoscandia, were tested. An automated computational technique was used which involved counting the sides superimposed on vectorized graphics using separated crystal boundaries. The results were obtained for olivine, orthopyroxene, clinopyroxene, and plagioclase. On this basis, an interpretation of the mineral box fractal dimension was made, along with an interpretation of its nature in the rock in which it was found. The performed calculations were applied to the sampling positions, and maps of changes in fractal dimensions were prepared. The nature of the minerals studied was correlated with the type of rocks present in Monchepluton. Then, the fractal dimensions were scaled to a percentage scale determining the mean value for the euhedral crystal as 100%, and a map was obtained representing the advancement of secondary processes after summing these data for all four investigated minerals. This method was analyzed and its advantages and limitations shown.

CONTACT PROBLEM FOR ORTHOTROPIC PLATES OF VARIABLE THICKNESS WITH A SPATIALLY INHOMOGENEOUS BASE

В работе приведено численное моделирование пространственной задачи контактного взаимодействия ортотропных плит переменной жесткости с упругими основаниями. Используемая методика расчета пригодна в случае любых известных контактных моделей упругих оснований. В качестве примера приведены численные результаты для пространственно-неоднородных оснований типа упругих слоев постоянной и переменной толщины. Система интегро-дифференциальных уравнений, к которой сводится задача, решается численно, сочетанием методов конечных разностей типа сквозного счета и граничных элементов. Найдены прогибы, изгибающие моменты и распределения контактных давлений прямоугольной плиты переменной жесткости, полностью примыкающей к основанию. Приводится анализ влияния на напряженно-деформированное состояние плиты, изменения ортотропных свойств ее материала и степень неравномерной сжимаемости толщи грунта. Разработанная методика позволяет эффективно моделировать работу плитных фундаментных конструкций, когда необходим учет неоднородности грунтов сжимаемой толщи в пределах габарита зданий или сооружений. The paper presents a numerical simulation of the spatial problem of contact interaction of orthotropic slabs of variable stiffness with elastic foundations. The calculation technique used is suitable for any known contact models of elastic foundations. As an example, numerical results are given for spatially inhomogeneous foundations such as elastic layers of constant and variable thickness. The system of integrodifferential equations, to which the problem is reduced, is solved numerically by a combination of finite difference methods such as end-to-end counting and boundary elements. Deflections, bending moments and contact pressure distributions of a rectangular slab of variable stiffness, completely adjacent to the base, are found. An analysis of the influence on the stress-strain state of the slab of changes in the orthotropic properties of its material and the degree of uneven compressibility of the soil thickness is given. The developed technique makes it possible to effectively simulate the operation of slab foundation structures when it is necessary to take into account the heterogeneity of the soil of the compressible strata within the dimensions of buildings or structures.

Combinatorial aspects of the Löwenstein avoidance rule. Part I: the independence polynomial

According to Löwenstein's rule, Al–O–Al bridges are forbidden in the aluminosilicate framework of zeolites. A graph-theoretical interpretation of the rule, based on the concept of independent sets, was proposed earlier. It was shown that one can apply the vector method to the associated periodic net and define a maximal Al/(Al+Si) ratio for any aluminosilicate framework following the rule; this ratio was called the independence ratio of the net. According to this method, the determination of the independence ratio of a periodic net requires finding a subgroup of the translation group of the net for which the quotient graph and a fundamental transversal have the same independence ratio. This article and a companion paper deal with practical issues regarding the calculation of the independence ratio of mainly 2-periodic nets and the determination of site distributions realizing this ratio. The first paper describes a calculation technique based on propositional calculus and introduces a multivariate polynomial, called the independence polynomial. This polynomial can be calculated in an automatic way and provides the list of all maximal independent sets of the graph, hence also the value of its independence ratio. Some properties of this polynomial are discussed; the independence polynomials of some simple graphs, such as short paths or cycles, are determined as examples of calculation techniques. The method is also applied to the determination of the independence ratio of the 2-periodic net dhc.

Improving the accuracy of analyzing nuclear power plants operation based on calculation technique of maintenance and repair cost

Modern methods to calculate the operating (operational, maintenance and repair) component of the cost of electricity for nuclear power plants (NPPs) include the number of disparate techniques calculating the cost of materials, labor costs, machinery and equipment depreciation and amortization, overhead costs, and others. Maintenance and repair expenses (MRO) amount to approximately 20 % of the electricity cost. As a rule, they are calculated in fractions (percent) of amortization expenses. Subsequently it leads to a significant deviation of actual costs from the planned ones, making resource planning more difficult. Thus, the development of unified calculation technique of NPP MRO cost is a highly topical issue. The study is based on Russian and foreign research in the field of enterprise and industry planning and management, published in scientific periodical publications and Internet. Analytical, logical, and engineering-economic analysis are applied. This paper represents an attempt to systematize the organizational and methodological support of MRO implemented at Russian NPPs. The result of the study is the development of MRO cost calculation technique which considers the peculiarities of planning, preparation, arrangement and carrying out of NPP repair work. The technique counts rationing of labor, equipment, and materials costs; calculation of repair personnel wage including the allowances, surcharges, and bonuses for work in severe environment (high / low temperature, restricted conditions, work at height, in special clothing and with the use of personal protective equipment, etc.), in ionizing radiation environment. The method to calculate each component of the NPP MRO cost considering the fact by whom repair works are carried out (NPP staff or contractors) is given. The developed technique provides an increase of the accuracy of calculating the NPP MRO cost causing the timeliness and resource availability planning. It leads to NPP economic efficiency in the domestic and global nuclear technology market.