Buckling and post-buckling of prestressed stainless steel stayed columns

Prestressed stayed compression members are frequently required as very slender load-bearing structural components by both investors and architects. Behavior of these members depends on their geometrical and material properties, prestressing and boundary conditions. In the paper are discussed respective critical buckling loads and post-buckling paths with regards to 2D and 3D GMNIA (geometrically and materially nonlinear analysis with imperfections) using ANSYS software. Former tests and recent detailed analyses of other authors are commented with respect to the 3D analysis, level of imperfections, boundary conditions at central crossarm (fixed or sliding stays) and nonlinear stainless steel material

The conversation workshop: a tool to practice SL Oral production

"This thesis reports on a qualitative study concerning the conversation workshop as a tool to practice SL oral production. This study was carried out at a public university in a faculty of modern languages, which has a conversation workshop for SL learners. The primary objectives of this study were to investigate what motivates students to attend the conversation workshop, analyze students’ behavior in an autonomous environment as well as to analyze the features that make the conversation workshop a good alternative to practice the oral production. The research data was collect via observations and interviews that were applied to five students who attended the conversation workshop and that had different language levels. The research findings reveal that students that had attended the workshop had several personal and linguistic changes. In some cases, they became more confident when participating or speaking in front an audience. Others gained more vocabulary even they became more fluent. It was also found that students who attended the conversation workshop were more skilled to work in an autonomous environment and make decisions about their learning development"

Single-Crossarm Stainless Steel Stayed Columns

Stability and strength of imperfect stayed columns are studied in 3D using ANSYS software. Following three tests of stayed columns with a reasonable geometry, the numerical modelling is validated and subsequently compared with available analytical and numerical 2D results. Arrangement and values of prestressing of ties and initial deflections of the columns affecting the nonlinear stability problem are discussed in a detail. The effect of nonlinear stress-strain relationship corresponding to common stainless steel material is shown, with respect to loading level corresponding to loss of the column stability. The assembly technique of the stayed columns is taken into account, comparing the method and stability/strengths of columns with fixed or sliding stays in the connection to the central crossarm. Finally some recommendations concerning the analysis and use of such stayed columns are given

Single-Crossarm Stainless Steel Stayed Columns

Stability and strength of imperfect stayed columns are studied in 3D using ANSYS software. Following three tests of stayed columns with a reasonable geometry, the numerical modelling is validated and subsequently compared with available analytical and numerical 2D results. Arrangement and values of prestressing of ties and initial deflections of the columns affecting the nonlinear stability problem are discussed in a detail. The effect of nonlinear stress-strain relationship corresponding to common stainless steel material is shown, with respect to loading level corresponding to loss of the column stability. The assembly technique of the stayed columns is taken into account, comparing the method and stability/strengths of columns with fixed or sliding stays in the connection to the central crossarm. Finally some recommendations concerning the analysis and use of such stayed columns are given

Atmospheric DBD discharge modification of polyester fabric

This paper is focused on a study of treatment of polyester fabric by an atmospheric dielectric barrier discharge (DBD). The experiment has been done in air pumping regime. Modification efficiency was analyzed by a drop test measurement. A time dependent modification was observed. The positive effect of the plasma treatment is more prominent in the case of 360 s modification time. Stability of modification effect in time is also discussed.Внимание сосредоточено на изучении обработки полиэстерной ткани атмосферным диэлектрическим барьерным разрядом. Эксперимент был проведен в режиме с воздушной откачкой. Эффективность модификации была проанализирована капельным тестом. Предметом наблюдения являлась зависимость модификации от времени. Положительный эффект плазменной обработки наиболее заметен в случае времени модификации 360 с. Также обсуждается стабильность эффекта модификации.Увага зосереджена на дослiдженнi обробки полiестерної тканини атмосферним дiелектричним бар’єрним рoзрядом. Експеримент був проведений у режимi з повiтряною вiдкачкою. Эфективнiсть модифiкацiї була проаналiзована краплинним тестом. Предметом спостережень була залежнiсть модифікацiї вiд часу. Позитивний ефект плазмової обробки найбiльш помiтний у випадку з часом модифiкацiї 360 с. Також обговорюється стабiльнiсть ефекту модифікацiї

Computer supported interferogam evaluation

Paper presents a method of phase shift calculation and interpretation of complicated interferograms taken in the cylindrically symmetrical medium. Method is applicable for any finite–width interferogram, incl. those with individual closed interference fringes causes by abrupt changes of the refractive index. Phase shift calculation were performed in the MATLAB computing environment.Представлено метод обчислення й інтерпретації фазового зсуву складних інтерферограм, взятих в вісесиметричному проміжку. Метод може бути застосовано для будь-яких інтерферограм, включаючи ті, що мають особливості інтерференційних смуг, викликані раптовими змінами коефіцієнта переломлення. Обчислення фазового зсуву здійснювалося в комп'ютерному середовищі MATLAB.Представлен метод вычисления и интерпретации фазового сдвига сложных интерферограмм, взятых в осесимметричном промежутке. Метод применим для любых интерферограмм, включая те, что имеют особенности интерференционных полос, вызванные внезапными изменениями коэффициента преломления. Вычисление фазового сдвига осуществлялось в компьютерной среде MATLAB

PES fabric modification with a corona discharge

Paper presents results of experiments with polyethylene terephtalate (PET) focused on the applicability of atmospheric corona discharge for polyester fabric (PES) modification, mainly on the relation between corona discharge input power and the fabric’s hydrophobicity and modification efficiency. Modification effect strongly grew according to the discharge input power, but the growth was limited by the corona discharge conversion into the spark discharge. Modification effect aging expressed in the feathering spot size time changes sharply diminished in time. Results of corona discharge modification were compared with those of the RF discharge modificationВ роботі подаються результати експериментів з поліетилен-терфталатом (РЕТ), метою яких було виявлення можливості вживання атмосферного коронного розряду для модифікації поліефірного матеріалів (PES), головним чином, залежності гідрофобності матеріалів та ефективності їх модифікації від споживаної потужності коронного розряду. Ефект модифікації помітно зростав з споживаною потужністю, проте цей зріст обмежувався переходом коронного розряду в іскровий. Результати модифікації коронним розрядом порівнюються з результатами, які були одержані з застосуванням ВЧ розряду.В работе представлены результаты экспериментов с полиэтилен-терфталатом (РЕТ), целью которых было выяснение возможности применения атмосферного коронного разряда для модификации полиэфирного материалов (PES), главным образом, зависимости гидрофобности материалов и эффективности их модификации от потребляемой мощности коронного разряда. Эффект модификации заметно возрастал с потребляемой мощностью, но это возрастание ограничивалось переходом коронного разряда в искровой разряд. Результаты модификации коронным разрядом сравниваются с результатами, полученными при использовании ВЧ разряда

Plasma treatment in textile industry

Plasma technology applied to textiles is a dry, environmentally- and worker-friendly method to achieve surface alteration without modifying the bulk properties of different materials. In particular, atmospheric non-thermal plasmas are suited because most textile materials are heat sensitive polymers and applicable in a continuous processes. In the last years plasma technology has become a very active, high growth research field, assuming a great importance among all available material surface modifications in textile industry. The main objective of this review is to provide a critical update on the current state of art relating plasma technologies applied to textile industryFernando Oliveira (SFRH/BD/65254/2009) acknowledges Fundacao para a Cioncia e Tecnologia, Portugal, for its doctoral grant financial support. Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Cioncia 2008, Portugal

P. Buyse et W. Penninckx, Verzorgd Taalgebruik, 1977

Pichal William. P. Buyse et W. Penninckx, Verzorgd Taalgebruik, 1977. In: Équivalences, 9e année-n°2-3, 1978. pp. 87-88

Multilingual Vocabulary of Educational Radio and Television Terms, (English, French, German, Italian, Dutch, Spanish, Swedish) , 1971

Pichal William. Multilingual Vocabulary of Educational Radio and Television Terms, (English, French, German, Italian, Dutch, Spanish, Swedish) , 1971. In: Équivalences, 4e année-n°1, 1973. pp. 42-44