Прогнозирование и вероятностная оценка долговечности технических объектов

На основе методологии марковского анализа надежности предложен вероятностный подход к прогнозированию и оценке долговечности технических объектов. Разработана математическая модель прогнозирования долговечности с использованием статистических данных, характеризующих начальное и конечное распределение продолжительности срока службы технических объектов.На основі методології марківського аналізу надійності запропоновано ймовірнісний підхід до прогнозування та оцінки довговічності технічних об’єктів. Розроблено математичну модель прогнозування довговічності з використанням статистичних даних, що характеризують початковий та кінцевий розподіл тривалості терміну служби технічних об’єктів.Based on the methodology of the Markov analysis, a probabilistic approach to forecast and estimation of the longevity of technical objects is offered. A mathematical model of the longevity forecast is developed with the use of statistical data characterizing the initial and final distribution of the service term of technical objects

Theoretical basis for the formation of damaging factors during the coal aerosol explosion

Purpose. Assessing the process of damaging factors formation during the coal aerosol explosion in mine workings on the basis of theoretical research of the explosion of coal dust deposits in order to substantiate promising methods of protecting miners from their impact. Methods. An integrated approach is used, which includes a critical analysis of literature data on the occurrence and development of coal aerosol explosions in mine workings; theoretical research into the state of the gaseous medium at the characteristic points of the development diagram of the coal dust deposits explosion as a result of mining operations based on the laws of classical physics and chemistry. Findings. The main aspects of the explosion mechanism of dust in a powdery state, accumulated on the surfaces along the mine working perimeter, and the formation of such negative factors as the effect of gaseous medium accelerated movement, have been revealed; high temperature formed during coal and methane detonative combustion; increased gas pressure. The revealed aspects of the dust explosion mechanism make it possible to determine the main directions for protection of miners caught in the explosion. The diagram of the development of settled coal dust explosion along the mine working with normal ventilation conditions, taking into account the influence of seismic waves, has been improved. Originality. Analytical dependences, reflecting the value of gas energy at characteristic points of the diagram, have been determined, and the dynamics of the formation of negative factors caused by the explosion have been revealed. Practical implications. Possible ways of protecting miners from the impact of negative factors caused by the coal aerosol explosion and reducing the severe consequences of such accidents are proposed.Мета. Оцінка процесу утворення вражаючих факторів під час вибуху вугільного аерозолю в гірничій виробці на основі теоретичних досліджень вибуху вугільних пилових відкладень для обґрунтування перспективних шляхів захисту гірників від їх впливу. Методика. Використано комплексний підхід, що включає критичний аналіз літературних даних щодо виникнення та розвитку вибухів вугільного аерозолю в гірничих виробках; теоретичні дослідження стану газового середовища в характерних точках схеми розвитку виробкою вибуху вугільних пилових відкладень на основі законів класичних фізики і хімії. Результати. Розкрито основні аспекти механізму вибуху пилу, який знаходиться у порошкоподібному стані у вигляді скупчень на поверхнях по периметру гірничої виробки, і утворення негативних факторів, таких як дії прискореного руху газового середовища; високої температури що утворюється при детонаційному згорянні вугілля і метану; підвищеного газового тиску. Виявлення аспекти механізму вибуху пилу дали можливість встановити основні напрямки захисту гірників, захоплених вибухом. Удосконалено схему розвитку вибуху осілого вугільного пилу у виробці з нормальними умовами провітрювання з урахуванням впливу сейсмічних хвиль. Наукова новизна. Встановлено аналітичні залежності, що відображають величину енергії газів у характерних точках схеми, розкрито динаміку утворення негативних факторів вибуху. Практична значимість. Запропоновано можливі шляхи захисту гірників від дії негативних факторів вибуху вугільного аерозолю та зменшення важких наслідків такого роду аварій.Цель. Оценка процесса образования поражающих факторов при взрыве угольного аэрозоля в горной выработке на основе теоретических исследований взрыва угольных пылевых отложений для обоснования перспективных путей защиты горняков от их влияния. Методика. Использован комплексный подход, включающий критический анализ литературных данных о возникновении и раз-витии взрывов угольного аэрозоля в горных выработках; теоретические исследования состояния газовой среды в характерных точках схемы развития выработкой взрыва угольных пылевых отложений на основе законов классической физики и химии. Результаты. Раскрыты основные аспекты механизма взрыва пыли, находящейся в порошкообразном состоянии в виде скоплений на поверхностях по периметру горной выработки, и образования негативных факторов, таких как действия ускоренного движения газовой среды; высокой температуры образующегося при детонационном сгорании угля и метана; повышенного газового давления. Выявленные аспекты механизма взрыва пыли позволили установить основные направления защиты горняков, застигнутых взрывом. Усовершенствована схема развития взрыва отложившейся угольной пыли в выработке с нормальными условиями проветривания с учетом влияния сейсмических волн. Научная новизна. Установлены аналитические зависимости, отражающие величину энергии газов в характерных точках схемы, раскрыта динамика образования негативных факторов взрыва. Практическая значимость. Предложены возможные пути защиты горняков от действия негативных факторов взрыва угольного аэрозоля и уменьшения тяжелых последствий такого рода аварий.The authors express their gratitude to the management of the Donetsk National Technical University of the Ministry of Education and Science of Ukraine for their support during conducting the research and presenting the results

Species of the water-fern megaspore genus Molaspora from a Cenomanian deposit in western France::occurrence, sporoderm ultrastructure and evolutionary relationships

The partially reticulate sculpture of Molaspora aspera sp. nov., a marsileaceous megaspore from a Cenomanian deposit in western France, distinguishes it from other species of Molaspora. An acrolamella entirely surrounds and obscures a small tetrad scar, a feature that has been demonstrated hitherto within members of the genus only in M. fibrosa. It was also encountered for the first time in M. lobata, with which the new species is associated in the same French mesofossil assemblage. The ultrastructure of the sporoderm of M. aspera is similar to that of M. lobata, but differs particularly in that the inner epispore is markedly thicker and may also contain numerous large, homogeneous spherules or, alternatively, holes of comparable dimensions and only a few small spherules. It is possible that these are a response to some hostile bacterial or other activity when the developing sporoderm was partially permeable. The cavity replacing part of the epispore in one of the specimens, and in the specimen of M. lobata examined, may be a preservational feature or have served to increase buoyancy of the spore in water. Molaspora lobata is very similar to megaspores of fossil and extant Regnellidium, but M. aspera bears some resemblance to other members of extant Marsileaceae and certain species of Cretaceous Arcellites, although there are significant differences between them. This suggests that Molaspora is a heterogeneous taxon embracing megaspores produced by water ferns of more than one natural genus, of which only Regnellidium has survived to the present dayPeer reviewe

The exine ultrastructure of the Permian pollen genus Plicatipollenites Lele 1964

The fine morphology of Plicatipollenites malabarensis (Potonié and Sah) Foster, 1975 from the Early Permian Al Khlata Formation, Oman was studied using light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). A ‘crochet-like’ sculpture is visible on both sides of the corpus in SEM. On ultramicrographs, this sculpture is distinguishable as a thin undulating ectexinal layer. The darkened area around the proximal trilete scar visible in transmitted light reflects a slight endexinal thickening in that area. The reticulate ornament of the saccus seen in LM is a result of superimposed superficial folds and inner ectexinal partitions. The saccus is filled with ectexinal partitions, many of which are radially orientated; its protosaccate appearance might be due to compression. The endexine is prominent and homogeneous. However, the presence of several indistinct lamellae in a less compressed region implies the originally lamellate form of the endexine. Morphological data on Plicatipollenites gondwanensis (Balme and Hennelly) Lele 1964 from the same deposits and Cordaitina Samoilovich, 1953 from the Permian of Russia (Kungurian of Cis-Urals and Kazanian of Siberia) are used for comparison. These taxa are similar in the corpus sculpture, thick, apparently homogenous but ontogenetically lamellate endexine. Differences between Plicatipollenites and Cordaitina include the presence of an endexinal fold encircling the corpus in the former genus and certain dissimilarity in the ultrastructure of the proximal scar. Nonetheless, both genera show a complicated ultrastructure of the proximal scar region implying that the scars might have served as apertures

The pollen ultrastructure of Williamsoniella coronata Thomas (Bennettitales) from the Bajocian of Yorkshire

The exine ultrastructure of Williamsoniella coronata Thomas from the Bajocian of Yorkshire (United Kingdom) was investigated with light, scanning electron, and transmission electron microscopy. The pollen averages 16.5 μm alongitsshort axisand24.5μmalongitslongaxis andismonosulcate, and thenonapertural sculpturingisdistinctly verrucate. The pollen wallishomogeneous, and the sulcus membraneiscomposedofthin exine withscattered small granules. The pollen grains differ in exine sculpturing and pollen wall ultrastructure from pollen grains of the bennettitalean taxa Cycadeoidea dacotensis (MacBride) Ward and Leguminanthus siliquosis (Leuthardt) Kraeusel. They are similar todispersed pollen grainsof Granamonocolpites luisae Herbst from the Triassic Chinle Formation of the United States, supporting the bennettitalean affinity of these dispersed pollen grains. The Bennettitales are palynologically characterized by monosulcate boat-shaped pollen with a homogeneous or granular pollen wall ultrastructure

The exine ultrastructure of Pretricolpipollenites bharadwajii from the Permian of Jordan

Dispersed trisulcate pollen grains of Pretricolpipollenites bharadwajii from the ?latest Permian of Jordan were studied with light, scanning, and transmission electron microscopy. The three sulci are located on the disal side. The median sulcus is usually longer, wider than the other two sulci, and has rounded aperture ends. The exine sculpturing and aperture membrane are scabrate. The ectexine includes a thick tectum, granular infratectum, and thin foot layer. The endexine is lamellate. A comparison with the closest similar genus Eucommiidites suggests overlapping characters; though the position of the three sulci on the distal side in Pretricolpipollenites bharadwajii and sulci on different sides in Eucommiidites indicates a possible distinguishing feature. Studies of exine ultrastructure of the other two Pretricolpipollenites species are needed to support or discard the distinction of Pretricolpipollenites and Eucommiidites

Blood Plasma Markers in Depressed Mice under Chronic Social Defeat Stress

It has previously been shown that, in mice, chronic social defeat stress in daily agonistic interactions leads to a depression-like state similar to that in depressive patients. With this model, it has become obvious that it is possible to study peripheral markers of the depression-like state in an experiment. This paper was aimed at searching for protein markers in the blood plasma of depressed mice in the chronic social conflict model, which allows for us to obtain male mice with repeated experiences of defeat. Proteomic analysis of blood plasma samples was conducted to identify proteins differentially expressed in this state. There were changes in the expression levels of the amyloid proteins SAA1, SAA4, and SAMP and apolipoproteins APOC3, APOD, and ADIPO in the blood plasma of depressed mice compared with controls (unstressed mice). Changes in the expression of serine protease inhibitors and/or proteins associated with lipid metabolism, inflammation, or immune function [ITIH4, SPA3, A1AT5, HTP (HP), CO9, and A2MG] were also found. Here, we showed that chronic social stress is accompanied by increased levels of amyloid proteins and apolipoproteins in blood plasma. A similarity was noted between the marker protein expression changes in the depressed mice and those in patients with Alzheimer’s disease. These data indicate a psychopathogenic role of chronic social stress, which can form a predisposition to neurodegenerative and/or psychoemotional disorders