Computational and experimental studies of the strength of full-scale samples of pipes with defects "metal loss" and "dent with groove"

Author(s):  
Dmitry A. Neganov ◽  
◽  
Victor M. Varshitsky ◽  
Andrey A. Belkin ◽  
◽  
...  

The article contains the comparative results of the experimental and calculated research of the strength of a pipeline with such defects as “metal loss” and “dent with groove”. Two coils with diameter of 820 mm and the thickness of 9 mm of 19G steel were used for full-scale pipe sample production. One of the coils was intentionally damaged by machining, which resulted in “metal loss” defect, the other one was dented (by press machine) and got groove mark (by chisel). The testing of pipe samples was performed by applying static internal pressure to the moment of collapse. The calculation of deterioration pressure was carried out with the use of national and foreign methodical approaches. The calculated values of collapsing pressure for the pipe with loss of metal mainly coincided with the calculation experiment results based on Russian method and ASME B31G. In case of pipe with dent and groove the calculated value of collapsing pressure demonstrated greater coincidence with Russian method and to a lesser extent with API 579/ASME FFS-1. In whole, all calculation methods demonstrate sufficient stability of results, which provides reliable operation of pipelines with defects.


2021 ◽  
Vol 2021 (10) ◽  
pp. 45-52
Author(s):  
Denis D'yakov ◽  
Iskander Valiulin ◽  
Dmitriy Lihovidov ◽  
Aleksey Velikanov

The purpose of the research in this paper is to develop a promising airfield driverless tow truck to increase the economic efficiency of aircraft towing facilities, including unmanned aircrafts as well as to ensure reliable operation in various climatic conditions. The research methods include the analysis of the experience of using such driverless airfield tow trucks abroad, the theory of calculating traction and speed indicators and experimental studies conducted during the creation and study of field tests of devices used to load the driving wheels of a tractor. To achieve the goal, the configuration of the structure being designed and its intended composition are determined analytically. The operation of the designed device in the traction mode is considered, and the characteristic of calculating its indicators when moving along the support surface is presented. The presented material briefly illustrates the process from creating a model of a driverless airfield tow truck to the created design of an existing sample, which will later be used to conduct its full-scale tests and a comprehensive assessment of its strength traction and speed characteristics.



Author(s):  
Ina Grau ◽  
Jörg Doll

Abstract. Employing one correlational and two experimental studies, this paper examines the influence of attachment styles (secure, anxious, avoidant) on a person’s experience of equity in intimate relationships. While one experimental study employed a priming technique to stimulate the different attachment styles, the other involved vignettes describing fictitious characters with typical attachment styles. As the specific hypotheses about the single equity components have been developed on the basis of the attachment theory, the equity ratio itself and the four equity components (own outcome, own input, partner’s outcome, partner’s input) are analyzed as dependent variables. While partners with a secure attachment style tend to describe their relationship as equitable (i.e., they give and take extensively), partners who feel anxious about their relationship generally see themselves as being in an inequitable, disadvantaged position (i.e., they receive little from their partner). The hypothesis that avoidant partners would feel advantaged as they were less committed was only supported by the correlational study. Against expectations, the results of both experiments indicate that avoidant partners generally see themselves (or see avoidant vignettes) as being treated equitably, but that there is less emotional exchange than is the case with secure partners. Avoidant partners give and take less than secure ones.



Derrida Today ◽  
2010 ◽  
Vol 3 (1) ◽  
pp. 21-36
Author(s):  
Grant Farred

‘The Final “Thank You”’ uses the work of Jacques Derrida and Friedrich Nietzsche to think the occasion of the 1995 rugby World Cup, hosted by the newly democratic South Africa. This paper deploys Nietzsche's Zarathustra to critique how a figure such as Nelson Mandela is understood as a ‘Superman’ or an ‘Overhuman’ in the moment of political transition. The philosophical focus of the paper, however, turns on the ‘thank yous’ exchanged by the white South African rugby captain, François Pienaar, and the black president at the event of the Springbok victory. It is the value, and the proximity and negation, of the ‘thank yous’ – the relation of one to the other – that constitutes the core of the article. 1



Paragraph ◽  
2015 ◽  
Vol 38 (2) ◽  
pp. 214-230
Author(s):  
Haun Saussy

‘Translation’ is one of our all-purpose metaphors for almost any kind of mediation or connection: we ask of a principle how it ‘translates’ into practice, we announce initiatives to ‘translate’ the genome into predictions, and so forth. But the metaphor of translation — of the discovery of equivalents and their mutual substitution — so attracts our attention that we forget the other kinds of inter-linguistic contact, such as transcription, mimicry, borrowing or calque. In a curious echo of the macaronic writings of the era of the dawn of print, the twentieth century's avant-garde, already foreseeing the end of print culture, experimented with hybrid languages. Their untranslatability under the usual definitions of ‘translation’ suggests a revival of this avant-garde practice, as the mainstream aesthetic of the moment invests in ‘convergence’ and the subsumption of all media into digital code.



Author(s):  
M. A. Danilov ◽  
◽  
M. V. Drobysh ◽  
A. N. Dubovitsky ◽  
F. G. Markov ◽  
...  

Restrictions of emissions for civil aircraft engines, on the one hand, and the need in increasing the engine efficiency, on the other hand, cause difficulties during development of low-emission combustors for such engines.



2021 ◽  
Vol 45 (2) ◽  
pp. 186-196
Author(s):  
Paulina Szwed ◽  
Małgorzata Kossowska ◽  
Marcin Bukowski

AbstractAccording to the principle of energy-conservation principle, effort investment is usually reduced in situations that are perceived as uncontrollable. This is because when success is recognized as impossible, any effortful actions are no longer justified. However, we predicted that individual differences in uncertainty tolerance, i.e., the need for closure (NFC), may moderate effort investment in uncontrollable situations. We tested this prediction in two experimental studies in which we exposed participants with differing levels of NFC to uncontrollable events, and indexed effort through the assessment of systolic blood pressure (SBP) responses. As predicted, in the uncontrollability (vs. controllability) condition, effort investment decreased significantly among low- but not high-NFC participants. Since gaining certainty and achieving closure is not a critical epistemic goal for low-NFC individuals, exerting extra effort to gain certainty is therefore no longer justified. On the other hand, high-NFC participants do not withhold their efforts, as they are highly motivated to obtain certainty. These results may help to account for contradictory findings in effort-investment behaviour and add substantively to the literature concerning motivation toward closure.



Author(s):  
N.B. Afonina ◽  
A.V. Otrokov ◽  
G.Sh. Khazanovich

Most modern roadheaders of selective action are equipped with loading devices with gathering-stars, which have a simpler drive design and increased reliability. As a result of the experimental studies carried out at SRSPU (NPI), it was found that under certain conditions, it is possible to transfer large lump material of a pile into a fluidized state, which reduces the energy consumption of material loading. An increase in the number of beams of the gathering-stars reduces the influence of the other parameters of the loader. Analysis of the process of interaction of the gathering-star’s beam with the receiving conveyor’s side edge to avoid jamming of the picking gathering-star by a lump of material with the implementation of high dynamic loads, it is necessary to set the gathering-beams at an angle of at least 60 degrees against rotation.



2019 ◽  
Author(s):  
Hanna Gekle

The history of mental development on the one and the history of his writings on the other hand form the two separate but essentially intertwined strands of an archeology of Ernst Bloch´s thought undertaken in this book. Bloch as a philosopher is peculiar in that his initial access to thought rose from the depths of early, painful experience. To give expression to this experience, he not only needed to develop new categories, but first and foremost had to find words for it: the experience of the uncanny and the abysmal, of which he tells in Spuren, is on the level of philosophical theory juxtaposed by the “Dunkel des gerade gelebten Augenblicks” (darkness of the moment just lived) and his discovery of a “Noch-nicht-Bewusstes” (not-yet-conscious), thus metaphysically undermining the classical Oedipus complex in the succession of Freud. In this book, psyche, work and the history of the 20th century appear concentrated in Ernst Bloch the philosopher and contemporary witness, who paid tribute to these supra-individual powers in his work as much as he hoped to transgress them.



Author(s):  
Екатерина Александровна Витоженц ◽  
Александр Викторович Кобелев

Предложен новый способ контроля введения инъекционной иглы в просвет вены на основе измерений электрического импеданса с помощью смешанной системы электродов, состоящей из биполярного и тетраполярного звеньев. Исследованы альтернативные схемы расположения электродов при проведении контроля венозной пункции биоимпедансным методом - они имеют более сложную конструкцию, используют дорогостоящие специализированные коаксиальные иглы, не позволяют однозначно определить факт прокола стенки венозного сосуда, нуждаются в дополнительной фильтрации регистрируемого сигнала с целью корректной интерпретации результата. Эффективность предложенной методики проверялась в ходе экспериментальных исследований на 5 добровольцах. Результаты экспериментов позволили идентифицировать 4 стадии нахождения инъекционной иглы относительно верхней конечности: нет касания, касание кожного покрова, нахождение под кожей коже, попадание в просвет вены. Идентификация положений инъекционной иглы происходит в реальном времени без дополнительной фильтрации регистрируемого сигнала. Метод позволяет обнаружить момент прокола стенки венозного сосуда стандартной инъекционной иглой, что в дальнейшем позволит сэкономить на изготовлении специализированных многослойных игольчатых электродов и внедрить данный способ контроля за проведением венепункции в медицинскую практику. Дальнейшее развитие предложенного подхода предполагает идентификацию двойного прокола вены, дифференцирование типа ткани в процессе введения иглы и исследование возможности определения типа кровеносного сосуда A new method for controlling the penetration of an injection needle into the vein based on measurements of electrical impedance using a mixed system of electrodes consisting of bipolar and tetrapolar parts is proposed. Alternative schemes for the arrangement of electrodes for monitoring venous puncture using the bioimpedance method have been investigated - they have a more complex design, use expensive specialized coaxial needles, do not allow to unambiguously determine the fact of a puncture of the venous vessel wall, require additional filtering of the recorded signal in order to correctly interpret the result. The effectiveness of the proposed technique was tested in experimental studies on 5 volunteers. The results of the experiments made it possible to identify 4 stages of finding the injection needle relative to the upper limb: no touching, touching the skin, being under the skin of the skin, getting into the lumen of the vein. Identification of the positions of the injection needle occurs in real time without additional filtering of the recorded signal. The method allows detecting the moment of puncture of the wall of a venous vessel with a standard injection needle, which in the future will save on the manufacture of specialized multilayer needle electrodes and introduce this method of monitoring venipuncture into medical practice. Further development of the proposed approach involves the identification of a double vein puncture, differentiation of tissue type during needle insertion, and investigation of the possibility of determining the type of blood vessel



1998 ◽  
Vol 4 (1) ◽  
pp. 121-134
Author(s):  
Vladimir Stipetić

Tourism is recognised as an important economic, social and cultural factor in modem societies. However, statisticians still face an enormous challenge when it comes to measuring the economic importance of tourism for given national economy. In his paper author examines the position of tourism in System of National Accounts (SNA-as presented in the version from 1993) and in European System of Accounts (acronym ESA, from 1995). He comes to the conclusion that is impossible to get the full answers on the importance of tourism for the given national economy within those frameworks. The main reason for such conclusion he has found in the fact that tourism is the multifacet activity, with difficult concept to define, let alone measure. He gets the proof for his conclusion comparing the different methodologies for defining who is the tourist, finding six different criterias in application at the moment. The results obtained are, of course, differing considerably, what makes them strictly incompatibles. The comparison of such data is for that reason difficult to make and the comparative results are of limited use. Author advocates a need to make on international level a Unified Tourism Economic Account (UTEA), covering the main activities of tourism sector. He regards the existing work by OECD and WTO as a good basis for further work. Only when majority countries would make UTEA, based on accepted methodology, could be the cross-country comparison made on scientific basis.



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