Assembly features of threaded fastenings having various sizes when using shear ultrasonic vibrations

2021 ◽  
Vol 2021 (12) ◽  
pp. 26-30
Author(s):  
Ravil Nigmetzyanov ◽  
Sergey Sundukov ◽  
Alexandr Sukhov ◽  
Dmitriy Fatyukhin

The problems that arise from threaded fastenings assembly have been considered. A promising direction for solving emerging problems has been found. Research results of the effect of shear polarization ultrasonic vibrations on the parameters of the threaded fastenings are presented.

Author(s):  
Е.Г. Соколова

В настоящее время к производству плитной продукции и фанеры предъявлены ужесточенные требования, которые регулируются законодательством. Одной из проблем фанерного производства является уменьшение токсичности фанеры повышенной водостойкости до уровня, определяемого современными мировыми требованиями. Снижение содержания свободного формальдегида в фанере можно достичь с помощью применения специализированных связующих, модифицированных меламином. Использование меламина признано перспективным направлением развития современного фанерного производства. Изложены результаты исследования меламинокарбамидноформальдегидных смол с со- держанием меламина от 20 до 25%, а также результаты исследования влияния содержания меламина в меламинокарбамидноформальдегидной смоле на проч- ность и токсичность фанеры, изготовленной с применением этих смол. Даль- нейшие исследования направлены на совершенствование эксплуатационных свойств (прочность склеивания и токсичность продукции) и технологии фанеры повышенной водостойкости с применением МКФС с содержанием меламина 20%. Одним из эффективных способов повышения прочности клеевого соедине- ния и снижения токсичности фанеры является применение аэросила технического в качестве модификатора для синтетических смол. Разработан рациональный состав клея на основе меламинокарбамидоформальдегидной смолы для склеива- ния шпона. Приведены технологические параметры склеивания фанеры, изго- товленной с применением меламинокарбамидноформальдегидных смол, показатели ее прочности и токсичности. Currently, tightened requirements to production of particleboard and plywood products are presented which are regulated by law. One of the problems in plywood production is the reduction of the toxicity of plywood increased water resistance to the level determined by the modern world requirements. The decrease in the content of free formaldehyde in the plywood can be achieved through the use of special binders modified with melamine. The use of melamine is recognized as a promising direction of development of modern plywood production. The research results of melamine-carbamide-formaldehyde resins containing melamine from 20 to 25% and also results of research of influence of melamine in the melamine-carbamide-formaldehyde resin strength and current-sicnosti plywood, manufactured using these resins. Further research aimed at improving the operational properties (bonding strength and toxicity of products) and technologies of plywood increased water resistance with the use of MKFS resins containing 20% of melamine. One effective way of increasing the bonding strength and reduce the toxicity of the plywood is the use of Aerosil technical as a modifier for synthetic resins. Developed rational adhesive composition based on melamineformaldehyde resin for bonding veneers. The technological parameters of the bonding of plywood, manufactured melamine-carbamide-formaldehyde resins, indicators of its strength and toxicity.


Author(s):  
I. Brent Heath

Detailed ultrastructural analysis of fungal mitotic systems and cytoplasmic microtubules might be expected to contribute to a number of areas of general interest in addition to the direct application to the organisms of study. These areas include possibly fundamental general mechanisms of mitosis; evolution of mitosis; phylogeny of organisms; mechanisms of organelle motility and positioning; characterization of cellular aspects of microtubule properties and polymerization control features. This communication is intended to outline our current research results relating to selected parts of the above questions.Mitosis in the oomycetes Saprolegnia and Thraustotheca has been described previously. These papers described simple kinetochores and showed that the kineto- chores could probably be used as markers for the poorly defined chromosomes. Kineto- chore counts from serially sectioned prophase mitotic nuclei show that kinetochore replication precedes centriole replication to yield a single hemispherical array containing approximately the 4 n number of kinetochore microtubules diverging from the centriole associated "pocket" region of the nuclear envelope (Fig. 1).


2008 ◽  
Vol 17 (2) ◽  
pp. 62-68 ◽  
Author(s):  
Cathy Binger

Abstract Many children who use AAC experience difficulties with acquiring grammar. At the 9th Annual Conference of ASHA's Special Interest Division 12, Augmentative and Alternative Communication, Binger presented recent research results from an intervention program designed to facilitate the bound morpheme acquisition of three school-aged children who used augmentative and alternative communication (AAC). Results indicated that the children quickly began to use the bound morphemes that were taught; however, the morphemes were not maintained until a contrastive approach to intervention was introduced. After the research results were presented, the conference participants discussed a wide variety of issues relating to grammar acquisition for children who use AAC. Some of the main topics of discussion included the following: provision of supports for grammar comprehension and expression, intervention techniques to support grammatical morpheme acquisition, and issues relating to AAC device use when teaching grammatical morpheme use.


1981 ◽  
Vol 24 (4) ◽  
pp. 520-525 ◽  
Author(s):  
Bruce L. Plakke ◽  
Daniel J. Orchik ◽  
Daniel S. Beasley

Binaural auditory fusion of 108 children (4, 6, and 8 years old) was studied using three lists of monosyllabic words (WIPI) presented at two sensation levels (30 and 40 dB). The words were processed to produce three bandwidth conditions (100, 300, 600 Hz) and were administered via three presentation modes (binaural fusion 1, diotic, binaural fusion 2). Results showed improved discrimination scores with increasing age, sensation level, and filter bandwidth. Diotic scores were better than binaural fusion scores for the narrower bandwidth conditions, but the diotic enhancement effect was seriously compromised in the widest bandwidth (600 Hz) condition. The results confirmed the contention that prior research results were equivocal due, in large measure, to procedural variability. Methods for reducing such variability and enhancing the clinical viability of binaural fusion tasks are suggested.


2002 ◽  
Vol 7 (3) ◽  
pp. 221-224 ◽  
Author(s):  
Bernhard Wilpert

The paper presents an inside evaluation of the EuroPsyT project, funded by the EU Leonardo Program in 1999-2001. While standard research usually neglects to reflect on the internal and external constraints and opportunities under which research results are achieved, the paper stresses exactly those aspects: starting from a brief description of the overall objectives of the 11 countries project, the paper proceeds to describe the macro-context and the internal strengths and weaknesses of the project team, the internal procedures of cooperation,. and obstacles encountered during the research process. It winds up in noting some of the project's achievements and with a look towards future research.


1999 ◽  
Vol 15 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Rosario Martínez-Arias ◽  
Fernando Silva ◽  
Ma Teresa Díaz-Hidalgo ◽  
Generós Ortet ◽  
Micaela Moro

Summary: This paper presents the results obtained in Spain with The Interpersonal Adjective Scales of J.S. Wiggins (1995) concerning the variables' structure. There are two Spanish versions of IAS, developed by two independent research groups who were not aware of each other's work. One of these versions was published as an assessment test in 1996. Results from the other group have remained unpublished to date. The set of results presented here compares three sources of data: the original American manual (from Wiggins and collaborators), the Spanish manual (already published), and the new IAS (our own research). Results can be considered satisfactory since, broadly speaking, the inner structure of the original instrument is well replicated in the Spanish version.


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