Journal articles on the topic 'Threads'
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1
Pošta, J., P. Veselý, and T. Hladík. "Properties of threads created by thread inserts." Research in Agricultural Engineering 49, No. 1 (February 8, 2012): 27–31. http://dx.doi.org/10.17221/4948-rae.
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Several techniques are at disposal for production or repair of internal threads. The repair of threads by means of flexible thread inserts and the repair of threads by means of sold thin walled thread inserts belong to the most important ways. The properties of threads repaired using flexible and solid thin-walled thread inserts were experimentally verified and compared. Laboratory comparison of loading capacity of the threads according to observance of specified technological procedures was carried out. Durability and reliability of the repaired threads were verified in operation, while the threads endured long-time variable mechanical and temperature load.
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Grewal, A. S., and M. Sabbaghian. "Load Distribution Between Threads in Threaded Connections." Journal of Pressure Vessel Technology 119, no. 1 (February 1, 1997): 91–95. http://dx.doi.org/10.1115/1.2842272.
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Threaded connections are commonly employed in axial load-bearing equipment and pressure vessel components. There are a number of parameters that affect the load distribution between the threads and the stress concentration at the thread roots. These include the thread form, the thickness of walls supporting the threads, the pitch of threads, number of threads engaged, and the boundary conditions. In this paper, the influence of these parameters on the load distribution between threads is reported. Load distribution analyses in threaded connections is performed by analytical and by finite element methods. Square and buttress-type threads have been considered. Three-dimensional nonlinear finite element analyses on threaded connections have been performed using MSC/NASTRAN finite element code. The effect of clearance between the nonmating faces of threads as well as the presence of a flexible media between the mating faces of threads are investigated.
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Arun, C. P. "A Bedside Schizophrenia thought Disorder Scale." European Psychiatry 24, S1 (January 2009): 1. http://dx.doi.org/10.1016/s0924-9338(09)71349-5.
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Present classification systems for thought disorder lack consistency and require one to remember long-winded definitions limiting their use to research settings. as an extension of recent work in this area (World Congress, 2008), we classify the characteristic thought disorder patterns seen in schizophrenia according to the location of the lesion in notional "threads" of mental computational processes that string speech together. These threads must take both semantics and syntax into consideration in performing their function. When we speak - just as when we write - there is a natural hierarchy topic thread (the topic of the ‘essay’) and multiples of paragraph threads, sentence threads, clause threads, word threads and phoneme threads. Intuitively, we grade the severity of thought disorder depending upon whether a particular thread gets stuck (S), reconnects abnormally (R) or is absent altogether:I.paragraph thread R: Disjointed sentences S: Circumstantiality;II.topic threadR: Tangentiality S: Preoccupatory thinking;III.sentence threads R: Knight's move thinking S: Clause perseveration;IV.clause threads R: Word salad S: Word perseveration, fusion;V.word threads R: Incoherent sounds/ neologisms/ paraphasias S: Phoneme/syllable perseveration;VI.phoneme threads - Failure of production: Mutism.Of course, one must record all the lesions that are present at any given time. This scale incorporates a intuitive progression from mild to severe thought disorder in Schizophrenia. Using the STDS would allow the straightforward ‘bedside’ quantification of the severity of thought disorder and enforce discipline into the thought assessment section of the Mental State Examination.
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Takano, Atsushi, Ryuta Kitamura, Takuma Masai, and Sayaka Nishino. "Development of pre-molded internal thread on composite tubes." Composites and Advanced Materials 30 (January 1, 2021): 263498332110007. http://dx.doi.org/10.1177/26349833211000756.
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Premolded internal threads on composite tubes were developed. The composite tubes with threads on both ends were made using a mandrel with a male thread. The threads can be applied to struts with adjustable end fits and composite pressure vessels with threaded caps that enable disassembly for inspection and repair. Carbon fiber-reinforced plastic (CFRP) prepregs were laid up on a mandrel, wrapped with shrink tape, and cured in an oven. The threads were built-in, without using machine cutting, and the fibers on the thread were continuous through the thread and tubes for high strength. The thread was alternately rounded, convex, and concave in shape to enable CFRP prepregs to be laid up. Two types of specimen were made and tested. The layup sequence of specimen A was [0/h/90/h/0/h(1/2)]s, and that of specimen B was [0/h/90/h/90/h/0/h/90/h/90/h/90/h/90/h/0/h/90/90/0], where “h” denotes a helical layer along the concave part of the threads. The relation between load and strain is nonlinear because of the rounded shape of the threads; however, a simple and closed form analytical model was able to predict the strength of the threads and design of the threads. The model was compared with the experimental results. In addition, an application of threads for the pressure vessel of the hybrid rocket motor is also reported. The combustion test proceeded without failure. Visual inspection after the test indicated that the threads and tubes were not damaged, and thus, they can be applied to high-pressure and high-temperature rocket motors.
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Baragetti, Ph.D., S. "Effects of Taper Variation on Conical Threaded Connections Load Distribution." Journal of Mechanical Design 124, no. 2 (May 16, 2002): 320–29. http://dx.doi.org/10.1115/1.1456459.
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Threaded connections are used in a lot of mechanical and civil engineering applications and, nowadays, are perhaps the most developed and economical way to join two elements made of any kind of material. It is well known that when a bolt is screwed into a threaded hole, the first threads engaged bear more than half of the axial load induced by the make-up torque. This overload in correspondence with the first threads engaged, together with the steep stress gradient induced by the notch effect at the thread root, is the cause of dramatic fatigue failures. Moreover, it is on the first threads engaged, because of the presence of high contact loads on the flanks of the threads, that galling can arise and promote surface damage if the threaded connection has to be screwed and unscrewed many times. The object of this paper is to propose a numerical finite element procedure, confirmed by means of full-scale experimental tests, which makes it possible to quantify the effects induced by varying the taper of rotary shouldered connections (RSCs), in terms of stress state, loads carried by the threads and pressure on the thread flanks. RSCs are conical threaded connections used in the oil industry and the aim of the procedure is to provide the designer with a useful tool able to minimize the dangerous effects of galling and overload.
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Naila Gasanova, Naila Gasanova, Nijat Gaytaranov Nijat Gaytaranov, and Nijat Gojayev Nijat Gojayev. "RESEARCH ON THE TECHNOLOGY OF PREPARING PLASTIC AND THREADED COMPONENTS USING 3D PRINTING OR ADDITIVE MANUFACTURING." ETM - Equipment, Technologies, Materials 14, no. 02 (April 18, 2023): 154–59. http://dx.doi.org/10.36962/etm14022023-154.
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Threaded components play a crucial role in ensuring the safety and reliability of systems by joining components together. Proper selection of thread type and size, ensuring proper machining and storage of components, and addressing potential issues such as leakage, vibration, and misalignment all play a special role. It is known that there is a big difference in the nature of the destruction of metal and plastic threaded connections, in particular, when the nut is made of plastics, and the bolt is made of steel, or vice versa. In this regard, at present there is no consensus in assessing the strength of plastic threaded connections. On the one hand, it is recognized that, due to a more uniform distribution of the load, plastic threaded connections have a significant load capacity. Numerous examples of the use of plastic threaded connections in pressure pipelines, in large plastic parts subjected to dynamic loads, various loaded fasteners - all these examples confirm that plastic threaded connections can withstand very high loads. Production of a thread of plastic details is rather difficult, than on metals. It is connected with the physical-mechanical processes coming in the course of production of concrete thread details from plastic by method of pressing and casting under pressure. Also mechanics of formation of plastic threads on details of the oil-field equipment on the specific properties differ from the threads received by a machining method on metals. As thread surfaces on plastic details are formed in compression molds depending on materials and the modes: temperatures, pressure and time of production. These regime parameters and guided parameters play a part at a guaranty of physicalmechanical properties of details in the course of production. The use of plastic or polymer threads in the oil and gas industry is increasing due to their unique characteristics and advantages over traditional metal threads. Recently, 3D printing (additive manufacturing) has become more widely used for the preparation of plastic threads. The article will discuss the methods and characteristics of preparing plastic threaded components, as well as their advantages and certain incompatibilities. Keywords: threaded components, plastic threaded components, preparation methods, 3D and 4D printing.
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Rauf, Sakandar, Miguel A. Andrés, Olivier Roubeau, Ignacio Gascón, Christian Serre, Mohamed Eddaoudi, and Khaled N. Salama. "Coating of Conducting and Insulating Threads with Porous MOF Particles through Langmuir-Blodgett Technique." Nanomaterials 11, no. 1 (January 10, 2021): 160. http://dx.doi.org/10.3390/nano11010160.
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The Langmuir-Blodgett (LB) method is a well-known deposition technique for the fabrication of ordered monolayer and multilayer thin films of nanomaterials onto different substrates that plays a critical role in the development of functional devices for various applications. This paper describes detailed studies about the best coating configuration for nanoparticles of a porous metal-organic framework (MOF) onto both insulating or conductive threads and nylon fiber. We design and fabricate customized polymethylmethacrylate sheets (PMMA) holders to deposit MOF layers onto the threads or fiber using the LB technique. Two different orientations, namely, horizontal and vertical, are used to deposit MIL-96(Al) monolayer films onto five different types of threads and nylon fiber. These studies show that LB film formation strongly depends on deposition orientation and the type of threads or fiber. Among all the samples tested, cotton thread and nylon fiber with vertical deposition show more homogenous monolayer coverage. In the case of conductive threads, the MOF particles tend to aggregate between the conductive thread’s fibers instead of forming a continuous monolayer coating. Our results show a significant contribution in terms of MOF monolayer deposition onto single fiber and threads that will contribute to the fabrication of single fiber or thread-based devices in the future.
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Rauf, Sakandar, Miguel A. Andrés, Olivier Roubeau, Ignacio Gascón, Christian Serre, Mohamed Eddaoudi, and Khaled N. Salama. "Coating of Conducting and Insulating Threads with Porous MOF Particles through Langmuir-Blodgett Technique." Nanomaterials 11, no. 1 (January 10, 2021): 160. http://dx.doi.org/10.3390/nano11010160.
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The Langmuir-Blodgett (LB) method is a well-known deposition technique for the fabrication of ordered monolayer and multilayer thin films of nanomaterials onto different substrates that plays a critical role in the development of functional devices for various applications. This paper describes detailed studies about the best coating configuration for nanoparticles of a porous metal-organic framework (MOF) onto both insulating or conductive threads and nylon fiber. We design and fabricate customized polymethylmethacrylate sheets (PMMA) holders to deposit MOF layers onto the threads or fiber using the LB technique. Two different orientations, namely, horizontal and vertical, are used to deposit MIL-96(Al) monolayer films onto five different types of threads and nylon fiber. These studies show that LB film formation strongly depends on deposition orientation and the type of threads or fiber. Among all the samples tested, cotton thread and nylon fiber with vertical deposition show more homogenous monolayer coverage. In the case of conductive threads, the MOF particles tend to aggregate between the conductive thread’s fibers instead of forming a continuous monolayer coating. Our results show a significant contribution in terms of MOF monolayer deposition onto single fiber and threads that will contribute to the fabrication of single fiber or thread-based devices in the future.
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M, Moulyashree,, and Mahantesha, S. "Configurations of implant threads: A Review." Scholars Journal of Dental Sciences 10, no. 05 (May 3, 2023): 86–90. http://dx.doi.org/10.36347/sjds.2023.v10i05.002.
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The dental implants are used for replacement of missing teeth, and it’s have been widely used for restore the function, esthetic, speech, and patient confidence. It forms the contact between the implant and the bone. The implant threads are altered to improve the initial contact, primary stability, increase the surface area, and facilitate dissipation of loads at the implant and bone surface. Implant thread design is one of the key factors it determines the primary stability and stress distribution during osseointegration, the threaded implants are reduced both stress on bone and sliding distance between the implant and bone. The primary stability is play a important role in less bone quality, double and triple threaded implant increases the primary stability than single threaded implant, the implant threads distribute mechanical stress equally at bone implant interface, lead to stability of dental implants and less bone resorption and also higher thread profile improve the primary stability, the success or failure of implants depend on the thread designs and quality of bone.
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Midha, VIinay Kumar, Shailja Sharma, and Vaibhav Gupta. "Predicting sewing thread consumption for lockstitch using regression model." Research Journal of Textile and Apparel 20, no. 3 (September 12, 2016): 155–63. http://dx.doi.org/10.1108/rjta-08-2016-0019.
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Purpose This paper aims to develop a single regression model (instead of developing models separately for each thread type) to predict the sewing thread consumption for cotton and polyester staple spun threads. Design/methodology/approach A single regression model is developed for predicting sewing thread consumption for cotton and polyester threads. The polyester sewing threads have lower sewing thread consumption as compared to cotton threads because of their higher elongation behaviour. The model differentiates between the cotton and polyester sewing threads using their elongation values at peak levels of tensions experienced by the sewing threads during stitch tightening. By comparing the estimated thread consumption values with actual values, the effectiveness of model is evaluated with root mean square error and coefficient of determination (R2). Findings During the sewing process, by understanding the behaviour of different types of sewing threads, it is possible to develop a single regression model for all types of threads. Practical implications The sewing thread consumption can be easily calculated for cotton and polyester sewing threads using a single regression equation using the sewing assembly thickness, stitch density and elongation of thread at peak tension. The garment manufacturers need not depend on different charts for sewing thread consumption for stock management. Originality/value The sewing thread consumption is different for different types of threads, and garment manufacturers have to depend on different charts given by sewing thread manufacturers or use different equations for each type of threads. Using this single regression equation, sewing thread consumption for cotton and polyester sewing thread can be estimated accurately.
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Chauhan, P. S., C. M. Agrawal, and R. K. Dwivedi. "Effect of Material and Process Parameter on Dimensions of Rolled External Threads." Applied Mechanics and Materials 493 (January 2014): 453–60. http://dx.doi.org/10.4028/www.scientific.net/amm.493.453.
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The work in this paper presents the effect of material and blank dimension on the dimensions ofexternal rolled threads. This paper will be helpful for the auto industry, one of the largest fastenersmarkets, that typically consumes between 2800 to 3100 fasteners in the assembly of an average familyvehicle. Externally threaded fasteners comprise the bulk of fasteners used in these applications withover 90% of being produced by thread rolling. The thread rolling process is now widelyacknowledged as the fastest and most efficient method of producing accurate external threads, withsurface finish and mechanical properties. The typical production rates are around one piece persecond. In order to ensure a perfect thread rolling process, it is important for blank of work piece to beproperly pre-machined. The size of the blank is dependent on material, surface finish, type of threadsetc. This paper describes the effect of blank material and dimensions on nominal diameter of externalrolled threads. The work has been carried out at M/s Gayatri Auto Industries on Master ReciprocatingDies Thread Rolling Machine using HSS die. Mild Steel (C 15), EN-8 (C40), and EN-47 (SpringSteel) materials have been taken as blank material for the analysis to produce M8x1.25 6g threads.The result indicates that the variation on surface roughness, carbon percentage and dimension of blankaffects significantly the nominal diameter and PCD of threads. This paper is helpful for theprofessionals to determine the accurate dimension of thread rolling blank for desired threads tominimize rejections.
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Studenikin, R. V., A. V. Sushchenko, and A. A. Mamedov. "Influence of geometrical parameters of dental implants on secondary stability and osseointegration process depending on the type of bone." Endodontics Today 21, no. 2 (July 20, 2023): 148–53. http://dx.doi.org/10.36377/1683-2981-2023-21-2-148-153.
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Aim. Comparison of the secondary stability and osseointegration rate of dental implants with fine and coarse threads placed in bones of various types.Materials and Methods. The study considered the data of 60 implants with fine and coarse threads, installed in the bone types I-III. After two and six months, an analysis of the loss of marginal bone, micromotion tests were carried out, changes in the stability coefficients were determined by the method of frequency magnetic resonance.Results. The 30 coarse threaded implants showed higher secondary stability compared to the finely threaded implants in all three bone types. Marginal bone loss was observed for both types of implants only in type III bone – but when comparing the absolute values, it is noticeable that they are smaller with large threads. Micromotion was absent in all cases for bone types I and II. For implants with large threads in type III bone, micromotion was less than 30 μm, and for implants with fine threads, it was 150-160 μm.Conclusions. High secondary stability is typical for implants installed in type I-II bone, regardless of the thread pitch, but the value of the stability coefficient is higher for specimens with coarse threads. In addition, there is no loss of marginal bone in these cases. Finely threaded implants placed in Type III bone are subject to micromovement.
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Shilko, S. V., N. P. Glazyrin, P. N. Grakovich, V. V. Anichkin, and D. N. Bontsevich. "CHARACTERIZATION OF SURGICAL THREADS HANDLING PROPERTIES." Health and Ecology Issues 1, no. 2 (February 15, 2004): 145–50. http://dx.doi.org/10.51523/2708-6011.2004-1-2-28.
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The quality problem of surgical threads is discussed with account of their handling properties. With this aim, the mechanical characteristics of surgical threads based on natural (silk) and synthetic (polyamide, polyethylene terephthalate) fibres have been studied prior and after modification by inert in biological respect polymer coatings. The practical recommendations to estimation and controlling of handling properties of surgical threads have been proposed. The generalized deformational criteria have been proposed concerning bending stiffness, the force needed to form a node and relaxation rate of the deformed thread after unloading. These characteristics are the functions of elasticity modulus, viscosity, plasticity, hardness and friction coefficient of thread’s material, which may be measured by the standard mechanical tests. It’s shown that along with improved compatibility with biotissues soft coatings made of bioinert low-modular polymers are also capable of optimising handling parameters of threads.
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Prochor, Piotr, and Eugeniusz Sajewicz. "A Comparative Analysis of Standardised Threads for Use in Implants for Direct Skeletal Attachment of Limb Prosthesis: A Finite Element Analysis." Applied Bionics and Biomechanics 2019 (February 7, 2019): 1–10. http://dx.doi.org/10.1155/2019/8027064.
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The aim of the research was to determine the optimal thread’s shape to be used in implants for direct skeletal attachment of limb prosthesis. In addition, by testing appropriate parameters’ modification of the suitable thread, an attempt was made to maximise its effectiveness. The analyses included three thread types described in the ISO standards: shallow, symmetrical, and asymmetrical. The obtained results suggest that shallow thread ensures the lowest equivalent and directional stress peaks generated in the bone as well as favourable stress patterns and profiles during implant loading in relation to symmetrical and asymmetrical threads. Moreover, shallow thread ensured the generation of single equivalent and directional stress peaks, while symmetrical and asymmetrical threads provided additional stress peak for equivalent as well as for each of directional peaks. Subsequently, optimisation of the shallow thread’s shape was conducted by changing two relevant thread’s parameters (flank angle and rounding arc) which influence the generated stress distribution. The highest reduction of stress peaks was obtained while reducing the rounding arc by 0.2 mm. Therefore, it can be stated that the proposed modification of the HA thread can lead to obtaining a higher biomechanical effectiveness of implants for direct skeletal attachment of limb prosthesis.
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Prokofiev, Alexander, and Aleksandr Steshkov. "ADVANCED METHODS OF MACHINING INTERNAL THREADS." Transport engineering 2022, no. 6 (June 9, 2022): 4–10. http://dx.doi.org/10.30987/2782-5957-2022-6-4-10.
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The paper deals with the problems of machining internal threads by deformation with the use of burnishers and combined taps. Internal threads were cut with taps until recently, which is accompanied by a number of significant drawbacks, and they are most evident when obtaining threaded holes in highly plastic materials. In these cases, it is advisable to machine threads by plastic deformation with forming taps. Some variants of tool structures for improving the quality of the internal thread by deformation and combined machining are considered, and even dependencies for defining the parameters of tools and hole preparation are given. The novelty of the work is the features of the structure and geometry of the burnishers and combined taps for machining by the deformation of internal threads.
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Karasik, O. N., and A. A. Prihozhy. "ADVANCED SCHEDULER FOR COOPERATIVE EXECUTION OF THREADS ON MULTI-CORE SYSTEM." «System analysis and applied information science», no. 1 (May 4, 2017): 4–11. http://dx.doi.org/10.21122/2309-4923-2017-1-4-11.
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Three architectures of the cooperative thread scheduler in a multithreaded application that is executed on a multi-core system are considered. Architecture A0 is based on the synchronization and scheduling facilities, which are provided by the operating system. Architecture A1 introduces a new synchronization primitive and a single queue of the blocked threads in the scheduler, which reduces the interaction activity between the threads and operating system, and significantly speed up the processes of blocking and unblocking the threads. Architecture A2 replaces the single queue of blocked threads with dedicated queues, one for each of the synchronizing primitives, extends the number of internal states of the primitive, reduces the inter- dependence of the scheduling threads, and further significantly speeds up the processes of blocking and unblocking the threads. All scheduler architectures are implemented on Windows operating systems and based on the User Mode Scheduling. Important experimental results are obtained for multithreaded applications that implement two blocked parallel algorithms of solving the linear algebraic equation systems by the Gaussian elimination. The algorithms differ in the way of the data distribution among threads and by the thread synchronization models. The number of threads varied from 32 to 7936. Architecture A1 shows the acceleration of up to 8.65% and the architecture A2 shows the acceleration of up to 11.98% compared to A0 architecture for the blocked parallel algorithms computing the triangular form and performing the back substitution. On the back substitution stage of the algorithms, architecture A1 gives the acceleration of up to 125%, and architecture A2 gives the acceleration of up to 413% compared to architecture A0. The experiments clearly show that the proposed architectures, A1 and A2 outperform A0 depending on the number of thread blocking and unblocking operations, which happen during the execution of multi-threaded applications. The conducted computational experiments demonstrate the improvement of parameters of multithreaded applications on a heterogeneous multi-core system due the proposed advanced versions of the thread scheduler.
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Malkov, O. V., and M. A. Pandurov. "Comparative Analysis of the Accuracy of Milling Threads with Various Profiles." Proceedings of Higher Educational Institutions. Маchine Building, no. 7 (748) (June 2022): 3–15. http://dx.doi.org/10.18698/0536-1044-2022-7-3-15.
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The article considers the types of threads to be milled, as well as threads for which milling is not used, based on the analysis of the catalogs of manufacturers of thread cutters. To expand the scope of thread milling, a study of the accuracy of geometric shaping of internal threads of various profiles was made using a kinematic scheme with a parallel arrangement of thread and tool axes. On the basis of the geometric model of thread milling, a design scheme is presented and a program for shaping internal threads of various profiles is developed. Using the developed design experiment plan, a comparative analysis of metric, buttress, round threads and threads for connecting casing pipes was carried out, which allows obtaining the shape of the thread profile, assessing its errors, the straightness of the sides and the possibility of threading according to the accepted degree of accuracy. The results of the study can be useful to designers in designing thread mills and technologists to assessing the possibility of using thread milling in the processing threads of various profiles.
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Antonova, M. V., A. R. Ibatullina, A. S. Parsanov, and I. V. Krasina. "Study of the Effect of Plasma Treatment on the Mechanical Properties of Mineral Fiber Threads." Journal of Physics: Conference Series 2270, no. 1 (May 1, 2022): 012009. http://dx.doi.org/10.1088/1742-6596/2270/1/012009.
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Abstract The article describes methods for modifying glass and basalt fibers and threads, and composite materials from them. Special attention is paid to plasma methods. Twisted glass thread and basalt twisted thread are investigated in the work. Plasma treatment was used to modify the threads. The type of plasma is nonequilibrium, low-temperature; the type of discharge is high-frequency capacitive. The results of research of thread properties, such as morphological changes and breaking load of threads. The plasma-treated and non-treated samples of threads were compared. The modes of plasma modification of threads in which the increase of breaking load strength of glass threads up to 23 % and of basalt threads up to 10 % is achieved have been established.
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Mascenik, J. "Determination of the coefficient of friction in a screw joint loaded with a controlled torque." IOP Conference Series: Materials Science and Engineering 1199, no. 1 (November 1, 2021): 012073. http://dx.doi.org/10.1088/1757-899x/1199/1/012073.
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Abstract The aim of this article is mechanism description for the measuring the friction coefficient in the threads of threaded joint and consecutive experimental measuring of friction coefficient. The coefficient of friction in the threads of a bolt and nut depends on a number of factors, in particular the roughness of the surfaces, the properties of the lubricating film and the angle of the side of the thread. The coefficient is a function of the heat treatment, the quality of the surface protection substance, the size of the screw load and the pitch angle of the thread. The principal parameters of the measuring was fastening torque, which was choose by the torque wrench, axial strength, measured by axial force sensor, and calculated friction coefficient. The friction coefficient was calculated through the use of exponential equation of the torque balance in the screw. The value of the friction coefficient was examined on the threaded joint of size M20 without the plastic lubricants and with the plastic lubricants. Measured values of friction coefficient was close to values listed in the norm and makes argument that plastic lubricants can decrease the friction coefficient in the threads of threaded joint.
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Rickaby, Rachel, and Jeanine Sinclair. "Native versus invasive crab effluent effects on byssal thread production in the mussel, Mytilus trossulus (Gould, 1950)." Arbutus Review 9, no. 1 (September 25, 2018): 20–31. http://dx.doi.org/10.18357/tar91201818384.
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Mussels have evolved many adaptations to protect themselves, including the production of byssal threads. These are strong, proteinaceous fibres that mussels secrete to adhere themselves to rocks, preventing detachment by waves and predators. These byssal threads may be strengthened if mussels can recognize potential threats, such as native crabs, as their populations have a long history of coevolution. Unfortunately, the introduction of invasive predators poses a challenge for prey, which may not be capable of recognizing them. In this study, byssal thread production in the Pacific blue mussel (Mytilus trossulus ) was observed when exposed to effluent from the native red rock crab (Cancer productus) or the invasive European Green crab (Carcinus maenas). M. trossulus were placed in closed systems with effluent from either C. productus , C. maenas or control (no predator), over a 24-hour time period. Final measurements of number, length and diameter of byssal threads were recorded. M. trossulus exposed to effluent from C. productus produced byssal threads at a statistically significantly faster rate than in the control group over the first 7.5 hours. M. trossulus exposed to effluent from C. maenas produced byssal threads at a statistically significantly faster rate than both the C. productus and control groups. However, after 24 hours, there was no statistically significant difference between the mean number of byssal threads for any treatment. Additionally, we found no statistically significant difference between the mean diameter of byssal threads produced or length of byssal threads produced for any treatment.
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Šimić, Kristina, Ivo Soljačić, Domagoj Mudronja, and Tihana Petrović Leš. "Metal Content and Structure of Textiles in Textile Metal Threads in Croatia from 17th to 20th Century." Materials 15, no. 1 (December 29, 2021): 251. http://dx.doi.org/10.3390/ma15010251.
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Textile metal threads were used to decorate historical Croatian textiles. There are three basic types of metal threads usually used on historical textiles in Croatia. These are narrow stripes, wires, and combined metal textile yarn called “srma”, made of metal thread spirally wrapped around the nonmetal textile yarn. Textile yarns were made of silk, linen, wool, or cotton. Metal threads were primarily made of gold, silver, and copper, and different alloys of these metals or threads are layered in the structure. Analysis of metal threads with three different methods was made and the most adequate method for the analysis of metal threads from historical textiles was established. Metal thread analysis was performed with scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDX), which was determined to be the most suitable for the analysis of historical textiles if cross-section analysis of metal threads is also performed. Textile threads from combined metal textile threads were analysed with a light microscope. This information of the metal threads’ content and structure as well as the composition of textile thread can lead to an understanding of the technology of production threads and also temporal and spatial dating of textile objects which is helpful to conservators and restorers of valuable historical textiles.
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Cojocaru, Vasile, Calin Octavian Miclosina, and Zoltan Iosif Korka. "Fatigue Analysis of Large Diameter Threaded Connections Subjected to Dynamic Axial Loads." Applied Mechanics and Materials 658 (October 2014): 177–82. http://dx.doi.org/10.4028/www.scientific.net/amm.658.177.
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The large diameter threaded connections are components with high importance in the heavy mechanical systems. At the threaded elements subjected to variable loads one of the main causes of failure is represented by fatigue. This phenomenon is accentuated by the occurrence of high local stresses on the thread root. In this context, the correct evaluation of the local stresses and their correlation with the fatigue behaviour has a major importance in the correct assessment of remaining life of large diameter threaded connections.The paper is focused on the finite element analysis of the large diameter threaded bolts with two types of threads profiles: trapezoidal and square. For the two types of threads the simulations were performed using four nominal diameter and two different loading setups. The bolts were summited to static analysis in order to determine the local stresses distribution in the threaded area. The maximum values of Von Mises stresses obtained in the static analysis were exported to fatigue studies. The differences between the results obtained for the two types of threads are outlined.
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Lewandowska, Karina, Izabela Staniszewska, Milena Baran, Magda Turczynowicz, and Patrycja Retman. "Complications after polydioxanone threads (PDO) for facial lifting - a literature review." Journal of Education, Health and Sport 66 (April 19, 2024): 50072. http://dx.doi.org/10.12775/jehs.2024.66.010.
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Introduction: The popularity of cosmetic treatments is increasing, including treatments using polydioxanone (PDO) threads. Among the various complications that PDO threads can cause are swelling, skin dimpling, paresthesia, thread visibility/palpability, infection, and thread extrusion. On the other hand, it is an alternative to surgical facelift.
Purpose of work: To collect information on the complications after PDO threads for facial lifting.
Summary: In the literature review, there were reported complications after PDO threads for facial lifting as edema, allergy, inflammation, infection, skin dimpling, contour irregularity, visible threads, hematoma, thread extrusion, and incomplete facial paralysis. Knowledge of complications after face lifting with PDO threads allows us to prepare for these side effects and act appropriately in the event of their occurrence, thus avoiding the long-term effects of the cosmetic procedure.
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Hong, Gi-Woong, Hyewon Hu, Soo-Yeon Park, Jovian Wan, and Kyu-Ho Yi. "What Are the Factors That Enable Thread Lifting to Last Longer?" Cosmetics 11, no. 2 (March 12, 2024): 42. http://dx.doi.org/10.3390/cosmetics11020042.
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Thread-lifting traditionally addressed aging-related skin laxity by leveraging precise thread placement and traction. However, recent advancements, notably cog threads, expanded its application to younger patients seeking facial contour refinement. These newer threads effectively lift sagging areas and refine facial contours, broadening the procedure’s appeal. Challenges arise in selecting threads due to variable physician preferences and patient needs. Clear indications for thread efficacy are vital for credibility and tailored selection. Thread choice depends on tissue laxity, necessitating lighter threads for minimal laxity and stronger ones for significant sagging. However, no single thread universally suits all cases. Combining different threads is favored for optimal outcomes and minimizing side effects. Excessive traction post-procedure may lead to prolonged discomfort and skin irregularities. Post-procedural tension adjustments through massage remain debated, potentially conflicting with minimally invasive principles. Understanding thread characteristics guides tailored selection, considering patient conditions and procedural goals. This comprehensive understanding extends beyond specific products, aiming for optimal outcomes in thread-lifting procedures. Key factors influencing outcomes encompass thread materials, thickness, cog shapes, insertion depth, lifting vectors, and absorbable thread expiration dates.
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Tokarchuk, Oleksіі. "ANALYSIS OF THE INFLUENCE OF THE FORM AND DIMENSIONS OF THE CROSS-SECTION OF CLEANLESS TAPERS ON THE PROCESS OF EXTRACTING THREADS." Vibrations in engineering and technology, no. 2(97) (August 27, 2020): 108–22. http://dx.doi.org/10.37128/2306-8744-2020-2-12.
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The method of manufacturing internal threads with chipless taps, including mutual pumping of the tool and the workpiece, as in the manufacture of external thread profiles, so it cannot be entered into the knurling methods. Due to the specific features of the thread extrusion process, the study of the operational characteristics of rubber manufactured by chipless taps is of practical interest. The extrusion of threads occurs at a temperature not reaching the temperature of recrystallization of the metal of the workpiece, however, the physic mechanical properties of the surface layer of the metal of the threaded profile change. As a result of cold displacement of the threaded profile, the metal flows in the threaded contour. Extrusion of internal threads by chipless taps is a method of plastic deformation of a metal, in which a special tapping rod with a profile of the necessary thread is screwed into a workpiece opening, which has a diameter equal to approximately the average diameter of the thread. Under the action of torque, the tops of the turns of the tapered intake part of the tap penetrate the surface of the billet hole, the displaced metal moves in the radial direction, gradually increasing the height of the threaded profile. The actual geometry of the vertices of the tool cross-section contour has a significant effect on the thread extrusion process. Depending on the ratio of the contact planes of the tool and the workpiece, depending on the permissible amount of backing, the greatest torque is observed in hexagonal taps, and the smallest in trihedral taps. Depending on the accepted backing value, the ratio between the lengths and areas of the contacting sections, and accordingly, the ratio between the torques for taps with a different number of faces, also changes. It should be noted that in addition to the magnitude of the torque, the second parameter characterizing the process of extruding threads is the stability of the taps, which is not directly related to the magnitude of the torque, then the optimal number of faces is n = 3. If the optimal number of faces simultaneously satisfies two criteria (minimum torque and maximum tool life), then the optimal number of faces is determined experimentally in a specific case
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Threlfall, J., A. W. Hood, and P. K. Browning. "Flare particle acceleration in the interaction of twisted coronal flux ropes." Astronomy & Astrophysics 611 (March 2018): A40. http://dx.doi.org/10.1051/0004-6361/201731915.
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Aim. The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops.Methods. We have used a numerical scheme which solves the relativistic guiding centre approximation to study the motion of electrons and protons. The scheme uses snapshots from high resolution numerical MHD simulations of coronal loops containing two threads, where a single thread becomes unstable and (in one case) destabilises and merges with an additional thread.Results. The particle responses to the reconnection and fragmentation in MHD simulations of two loop threads are examined in detail. We illustrate the role played by uniform background resistivity and distinguish this from the role of anomalous resistivity using orbits in an MHD simulation where only one thread becomes unstable without destabilising further loop threads. We examine the (scalable) orbit energy gains and final positions recovered at different stages of a second MHD simulation wherein a secondary loop thread is destabilised by (and merges with) the first thread. We compare these results with other theoretical particle acceleration models in the context of observed energetic particle populations during solar flares.
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Lee, Jang-Jon, Boyeon An, Kiok Han, Ryangmi Lee, Ji Hyun Yoo, and Ji A. Yu. "A Scientific Analysis of Gold Threads Used in Donggungbi-Wonsam(Ceremonial Robe Worn by a Crown Princess, National Folklore Cultural Heritage No.48)." Journal of Conservation Science 37, no. 5 (October 31, 2021): 525–35. http://dx.doi.org/10.12654/jcs.2021.37.5.10.
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This study identified material properties through scientific analysis on Jikgeumdan(satin with gold threads) from Donggungbi-Wonsam and the gold threads used in the embroidery. The Donggungbi-Wonsam’s base of gold threads were estimated to have used mulberry fiber’s Korean paper(Hanji) because non-wood-based fibers were observed. The X-ray spectrometer showed that the Tongsuseulan of Donggungbi-Wonsam was a flat gold thread of pure gold and Jikgeumdan of flat silver thread of its Saekdong and Hansam. High sulfur levels were detected in the flat silver thread, which appeared to have formed silver sulfide by either manufacturing process using sulfur or conservation environment. he dragon insignia’s embroidery is also described as two types twisted gold threads; pure gold and alloying-gold and silver. while dragon insignia’s border line is decorated with a twisted gold thread of pure gold. In particular, it was investigated that adhesives such as an animal glue, a protein-based compound by gas chromatography mass spectrometry. Additionally, XRF and Raman spectroscopy analysis on the mixture substances between the metal surface and the base paper of gold threads identified talc and quartz in the gold threads and Seokganju(hematite) in the flat silver threads.
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Cai, Bai Song. "Study on Threaded Connection’s Strength in Gas Storage Well Using Finite Element Analysis." Advanced Materials Research 1021 (August 2014): 111–14. http://dx.doi.org/10.4028/www.scientific.net/amr.1021.111.
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Sealing property of threaded connection in gas storage wells is of great importance to the safety operation condition of CNG filling station. Indoor leakage tests of threaded-connect pipes are conducted and mathematical models to calculate the axial and thread contact stresses are established. Moreover, finite element analysis is used to figure out the maximum equivalent Von Mises stress in threaded connection. The results show that strain and stress of tested pipes have the linear distribution regularity. Also, it can be seen from the stress nephogram that the first to fourth pairs of threads bear 40% of the whole load and if the first pair has slip phenomena, other pairs of threads would be affected easily which leads to the possibility of gas storage well leakage.
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Istranov, A. L., and A. A. Chopikyan. "Thread lifting as a modern method of non-radical face rejuvenation." Issues of Reconstructive and Plastic Surgery 26, no. 3 (October 30, 2023): 15–25. http://dx.doi.org/10.52581/1814-1471/86/02.
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Purpose of the study: The purpose of this review of scientific literature is to collect, systematize and update modern ideas about the types, methods and principles of thread lifting, taking into account the basic requirements for efficiency and safety.In this paper, we reviewed publications presented in scientific databases: Web of Science, Scopus, PubMed, Cochran library, Medline, and PubMed Central. The keywords for searching for materials were: thread lift, thread lift history, thread lift sutures, face thread lift, polylactic threads, polydioxanone threads.The earliest approach to the effective use of thread rejuvenation techniques was the use of non-absorbable threads based on polypropylene, which are still successfully used along with modern threads, among which a special place is occupied by absorbable threads and new modifications of non-absorbable ones, complemented by various fixing design features (notches, cones).A large selection of threads, techniques and principles of correction allows specialists to create an individual management plan for each patient, and continuity and synergy between the sequential use of different modifications of threads allows one to prolong the results obtained and delay or refuse more radical anti-aging surgeries on the face.At the same time, as a result of the review of the scientific literature, no published studies were found on the comparative analysis of thread and surgical methods of rejuvenation, which requires further study.
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Mohammed, Maysoon A. "An Improved Dynamic Slicing Algorithm to Prioritize a Concurrent Multi-threading in Operating System." Iraqi Journal of Industrial Research 10, no. 3 (December 14, 2023): 11–21. http://dx.doi.org/10.53523/ijoirvol10i3id331.
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One of the issues with multi-threading in operating systems is the concurrency of operations or threads. In a multithreaded process on a single processor, the processor can switch execution resources between threads, enabling concurrent execution. Concurrency indicates that more than one thread is making progress, but the threads are not actually running simultaneously. The switching between threads occurs rapidly enough that the threads might appear to run simultaneously. In this paper, three related strategies for prioritizing multi-threading are presented: ACE-thread, Semaphore coprocessor, and the Concurrent Priority Threads Algorithm. The aim of this work is to enhance an existing prioritization algorithm, specifically the Concurrent Priority Threads Algorithm, by extending a dynamic slicing algorithm to prioritize multi-threading concurrently. The algorithm is designed to compute correct slices in multi-threading prioritization scenarios. Threads with the same highest priority can perform in a synchronized manner without encountering deadlocks. The C++ programming language is used to implement the extended algorithms. The improved algorithm achieved results that were 3% more accurate than the existing one. The outcomes of this work would facilitate the simultaneous execution of threads with the same priority, ultimately reducing waiting and processing times.
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Bontsevitch, D. N., and M. L. Kaplan. "THE CHARACTERISTICS OF FRICTION OF WATTLED SURGICAL THREADS MADE FROM OF THE TRADITIONAL SUTURAL MATERIAL." Health and Ecology Issues, no. 3 (September 28, 2013): 110–14. http://dx.doi.org/10.51523/2708-6011.2013-10-3-23.
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Purpose: to study the characteristics of friction of wattled surgical threads made from traditional sutural material. Materials and methods . The friction of dry and wet threads was studied on the apparatus «ComTen 94C» by the original developed technique. We fixed a cylindrical mandrel with a diameter of 40 mm, wrapped up with a rag of suede skin 18 cm long between the captures in horizontal position. After fixing the end of the thread in a mobile capture of the test car we made one turn round the mandrel and suspended weight of 50 g to the second end of the thread. The speed of the mobile capture movements made up 100 mm/min. Results. The experimental tests revealed the best sample in the group - the surgical thread of Ethibond firm covered with polibutilate. The polymeric covering of the surgical threads «Supramid Ergon sutramed» makes it possible to achieve the optimum indicators of friction in the group of the threads made from caprone. The best sample among the surgical threads made from silk is a thread by Silkam B/Braun firm with a covering made from wax and silicone. Conclusion. The modification of surgical threads by drawing a covering makes it possible to achieve optimum indicators of friction, to improve the handling qualities and gives threads the quality of autraumatics.
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Taras, І. P., and T. O. Pryhorovska. "Study on geometric features of conical threads." Scientific Bulletin of Ivano-Frankivsk National Technical University of Oil and Gas, no. 1(48) (June 29, 2020): 16–22. http://dx.doi.org/10.31471/1993-9965-2020-1(48)-16-22.
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The article studies the problem of oil/gas pipe conical thread reinforcement; in particular, the geometrical fundamentals for tool design for reinforcement. The article considers the main types of conical threads for pipes used in oil/gas industry. It was determined, that to obtain initial data for tools, used to reinforce thread crest and flank, it is necessary to consider conical threads not only as helical lines, but also as helicoid surfaces, to determine what helicoid parameters make the thread conical and obtain relations for the calculation of these geometric parameters. The authors determined geometrical parameters of conical threads and design parameters to develop rollers with deformed protrusions for simultaneous reinforcement of aforementioned thread crests and flank to improve tools for their frictional reinforcement. It was stated, that contrary to cylindrical threads, helicoid’s angles of inclination, which form conical threads, differ not only by the angle of inclination to the plane normal to their axes, but also by the values. The study of conical thread geometrical features refers to a cylindrical one allows to use these features in the design or improvement of tools for its manufacture and/or reinforcement. This approach allows improving the tools for frictional reinforcement of conical locking threads by modifying the lateral deforming elements. It makes possible to simplify tool manufacture, increase tool durability, reinforce the conical thread surface, and improve the quality, performance and economy of the conical thread frictional reinforcement.
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Chaaban, A., and M. Jutras. "Static Analysis of Buttress Threads Using the Finite Element Method." Journal of Pressure Vessel Technology 114, no. 2 (May 1, 1992): 209–12. http://dx.doi.org/10.1115/1.2929031.
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The finite element method has been used to investigate the stress field in threaded end closures of thick-walled high pressure vessels. A set of elastic analyses of vessels with 5, 8, 11, 15, 20 and 25 standard Buttress threads was used to propose a method for predicting the load distribution along the length of the thread. Root stress index factors in the region of the first three active threads are also included. The results of the present work contribute to the development of the new division of the ASME Pressure Vessel Code which is related to thick-walled high pressure vessels.
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Smith, Carol A., Rachel C. Skvirsky, and Ann M. Hirsch. "Histochemical evidence for the presence of a suberinlike compound in Rhizobium-induced nodules of the nonlegume Parasponia rigida." Canadian Journal of Botany 64, no. 7 (July 1, 1986): 1474–83. http://dx.doi.org/10.1139/b86-200.
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Parasponia rigida (Ulmaceae) nodules, like nodules of pea and alfalfa, are elongate and cylindrical and of indeterminate morphology. However, unlike other indeterminate nodules, the Rhizobium (Rp501) endosymbiont is not released into the host cell cytoplasm and remains confined to threads. Two types of threads are found: invasive infection threads that traverse the nodule tissue intracellularly and intercellularly; and threads confined to the nodule cell, proliferating intracellularly, which are the presumed sites of nitrogen fixation. The thread walls contain pectic and cellulosic components as evidenced by periodic acid – Schiff’s staining and digestion with pectinase and cellulase. Using histochemical analyses coupled with enzymatic and chemical extraction, we determined that the walls of the intracellularly confined threads also contain a suberinlike compound. The thread walls stain positively with Sudan black B and other lipid stains. In contrast, the invasive infection threads appear to be lignified as well as suberized.
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Rybak, Alexander, Besarion Meskhi, Dmitry Rudoy, Anastasiya Olshevskaya, Alexey Pelipenko, Yuliya Serdyukova, Svetlana Teplyakova, and Pavel Batura. "Analysis of multithreaded choke dividers and flow dividers-adders." BIO Web of Conferences 84 (2024): 02027. http://dx.doi.org/10.1051/bioconf/20248402027.
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Hydraulic drives, which for the most part is multi-circuit and branched, are widely used in hydraulic drives of modern mobile equipment and technological equipment. The analysis of the conducted studies has shown that throttle flow dividers, as well as flow dividers-adders, are the most suitable for providing automatic control of multi-circuit systems. Dividers are used to separate one working fluid flow entering the divided into two independent streams with an arbitrary flow ratio independent of loads. If it is necessary to organize a larger number of threads, two-threaded DP and DSP are switched on sequentially, and then one additional thread divider must be installed to receive each subsequent stream. Thus, in order to obtain n threads, it is necessary to have (n-1) two-threaded thread dividers, which is quite expensive and technically unjustified. The article describes the designs of multithreaded choke dividers and flow dividers-adders and a comparative analysis of their basic properties is carried out.
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Rengasamy, R. S., and D. Samuel Wesley. "EFFECT OF THREAD STRUCTURE ON TENSION PEAKS DURING LOCK STITCH SEWING." AUTEX Research Journal 11, no. 1 (March 1, 2011): 1–5. http://dx.doi.org/10.1515/aut-2011-110101.
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Abstract A dynamic sewing tension study was carried out with a tension probe on sewing threads with different structures, physical and tensile characteristics in a single needle lock stitch sewing machine. The needle thread recorded four major tension peaks corresponding to events occurring during sewing; bobbin thread withdrawal, stitch tightening, needle piercing the fabric and tightening of the needle thread around the shuttle, among which stitch tightening caused the maximum tension for all threads. Polyester filament and spun polyester threads exhibited the highest and lowest tightening tension, respectively. Multiple regression analysis showed that pre-tension and elastic modulus show positive influences while tex, bending, rigidity and compressibility of threads show negative effects on tension peaks during tightening and needle piercing. Sewing speed shows a positive impact only on the tension peak due to needle piercing. Pre-tension showed a prominent influence on tension peaks on all threads while the number of fabric layers failed to show any effect.
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Zhao, Yan, Xing Hua Qu, Yong Tian, Rui Jun Lu, and Hong Guang Liu. "Investigation on the Metrology of Conical Thread Gauge." Key Engineering Materials 693 (May 2016): 150–54. http://dx.doi.org/10.4028/www.scientific.net/kem.693.150.
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This paper presents a new method for the calibration of conical thread gauges. The procedure involves scanning of conical thread profiles, extracting all the thread main parameters, reconstructing the conical thread model. The metrologies model compared to the Standard one that is established on the basis of theoretical data. Thereby, the actual state of the threads can be fully identified by means of Screwing into the threaded length, which is good for control of the thread quality
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Wang, Fang, Song Xue, and En Jiang. "Study on Change of Chromium Plating Thickness of Threads of Control Rod Drive Mechanism of Nuclear Power." Materials Science Forum 956 (June 2019): 125–34. http://dx.doi.org/10.4028/www.scientific.net/msf.956.125.
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Control rod drive mechanism is one of the key main components in nuclear power plants and serves in harsh environments such as high temperature, high pressure and nuclear radiation. In order to ensure the service life and to prevent biting when assembling, some of the threads of control rod drive mechanism need to be chromium plated. In view of the high demands of the same chromium plating thickness on all surfaces of the threads of control rod drive mechanism of nuclear power and non-uniformity in chromium plating thickness of threads due to poor throwing power of chromium plating solution, five representative kinds of threads of control rod drive mechanism were selected and the plating thickness change of the root diameter, pitch diameter and crest diameter of threads was studied in this paper by means of depositing different thickness chromium coating on the surface of threads. The experimental results show that thicker coating is deposited on the crest of thread because of high current density and thinner coating is deposited on the root of thread because of low current density, which can provide reference for specification of chromium plating thickness of thread products of control rod drive mechanism.
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Heiler, Roland. "Cold thread Forming – the chipless alternative for high resistant internal threads." MATEC Web of Conferences 251 (2018): 02046. http://dx.doi.org/10.1051/matecconf/201825102046.
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In the area of construction and mechanical engineering the designers and production engineers very often do have the task to produce high resistant connections with the possibility of assembling and de assembling parts in a wide range of different materials. Most often connection bolts and internal threads are used to fulfill this task. To produce the internal threads typically the three following internal threading technologies are used: tapping, cold thread forming and thread milling. Tapping and thread milling are metal cutting technologies but cold thread forming is a chipless alternative. Due to the cold forming of the thread this process does have several benefits in comparison to the traditional cutting technologies, but also some special features and process characteristics have to be considered, that it is possible to produce reliable internal threads. In the article the technology is presented with information about the process characteristics, the modern tools design and typical application areas. Results of pull out tests are showing the possibility for producing high resistant threads.
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Nan, Rong Li, Xin Sun, Bo Zhao Shu, Hang Wang, Shang Yu Yang, Cai Hong Lu, and Li Hong Han. "Threaded Failure Analysis for Three-Dimensional Horizontal Wells Casing." Materials Science Forum 993 (May 2020): 1155–59. http://dx.doi.org/10.4028/www.scientific.net/msf.993.1155.
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In view of the external thread fracture during casing running in a well in Xinjiang Oilfield, the failure reasons of thread fracture were analyzed by combining the theory with experiment, and the casing safe service window with harsh working conditions was given. The operation of the failed casing and determined the actual working conditions of the casing threaded joints during the running process were investigated in this paper. According to the theoretical method, the boundary conditions and load conditions of the fracture casing joint in service were determined. With the aid of full-scale physical simulation test device, as well as the above boundary conditions and load conditions, the same batch casing tensile bearing characteristics were determined. Through nondestructive testing, the metallographic observation, scanning electron microscopy, spectral analysis and up-and-down test, the main controlling factors of casing thread fracture were determined. By the finite element analysis, the casing threads service state under axial tension and bending loads was established, the safety performance of threads under ideal working conditions was studied, and the fatigue mechanism of threads was revealed. Combined with the analysis results, the corresponding relationship between the casing tensile bearing characteristics and safety factor was given, which provides technical support for the safe service selection of casing body and thread under harsh conditions, saving cost and shortening the well construction period.
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Kibirkstis, Edmundas, Svitlana Havenko, Laura Gegeckienė, Svitlana Khadzhynova, and Myroslava Kadyliak. "Influence of Structure and Physical-Mechanical Characteristics of Threads on the Strength of Binding the Books." Mechanics 25, no. 4 (August 28, 2019): 313–19. http://dx.doi.org/10.5755/j01.mech.25.4.22774.
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In this study was analyzed the physical-mechanical properties and characteristics of different type of threads (linen, polyamide, cotton, polyester, silky) for blocks sewing. Investigated the brochure block binding with reduced threads surface friction coefficient, physical-mechanical parameters analysis. An important step in calculating the strength of threads for book sections and book blocks sewing is the choice of the strength criterion. For this purpose, are analyzed the influence of the structure of cotton and polyamide threads antifriction. Here was made the book binding process optimization with different types of the thread. It has been determined that the strongest book binding is with the polyamide type thread.
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Chen, Jian Min, Meng Zhang, and Jia Deng. "Optimal Design of Triangle Fastening Screw Thread's Turn Number." Advanced Materials Research 314-316 (August 2011): 657–60. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.657.
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The paper firstly numerically simulates the coupled model of triangle fastening screw threads in the application of ANSYS software. Calculate stress intensity of the screw thread on the axial pressure of 200MPa. The fittest coupled turn number of the screw nut is designed to make sure the strength of coupled teeth and make every turn of the screw thread go on very well and also save material. The maximum equivalent stress of the screw thread changes linearly with the axial pressure. The stress of the thread's root is greater than that of the thread's top so that the root is easily damaged. The paper's research method can apply to the optimal design of the other patterns of screw thread's turn number.
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Yakhimovich, V. A., A. B. Breki, A. A. Alkhimenko, M. K. Kurakin, D. V. Lyashenko, E. V. Ageev, S. N. Kutepov, and A. E. Gvozdev. "Methodology for Studying the Wear of Drill Pipe Threads during Repeated Making up and Holding under Load." Proceedings of the Southwest State University 24, no. 3 (December 6, 2020): 8–20. http://dx.doi.org/10.21869/2223-1560-2020-24-3-8-20.
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Purpose of reseach is to develop a methodology for studying the wear of drill pipe threads during repeated making up and holding under load. Methods. For the research, stand “IRS-1” was used. This stand is a device for creating a torque of up to 80 kNm and transferring it to a made-up pipe. It is equipped with a make-up torque sensor and a control system that performs make-up until the specified tightening torque is achieved or periodically applies the torque to the made-up thread pair. The test procedure for IRS-1 stand consists of the following sequence of actions: before starting the tests, the threaded protectors are removed; the threads on the nipple and sleeve are cleaned of the preservative grease and traces of corrosion by dry wiping and subsequent degreasing; the thread on the nipple is measured according to the measurement chart using a gauge. The gauge is made on the basis of the threaded surface impression and is a plate with cutouts in the form of a cross-section of four threads. The gap between the gauge and the thread is measured using a set of probes from 0.01 to 0.09 mm in increments of 0.01 mm, over 0.1 mm to 0.45 mm in increments of 0.05 mm, over 0.5 mm to 1 mm in increments of 0.1 mm. Results. A new tribotechnical stand of IRS-1 model was designed and created, which allows implementing various techniques for studying the wear of drill pipe threads during repeated making-up and holding under load. An important feature of the designed stand is a make-up torque sensor and a control system that perform make-up until the specified tightening torque is achieved or periodically applies the torque to the made-up threaded pair. The maximum torque generated by the stand is 80 kNm. A particular technique was developed. The technique includes the requirements of the API 7G-2 standard and has shown its effectiveness in the study of thread wear of steel drill pipes. To implement the technique, a special gauge was developed on the basis of the threaded surface impression and is a plate with cutouts in the form of a cross-section of four threads. Within this technique, a measurement chart with two selected measurement areas was developed. An algorithm for making up a pipe at a uniform speed was created. The algorithm includes three stages. There was developed an algorithm of measurements using reference marks, providing measurements at four points in each selected area. Conclusion. The results obtained can be used to create resource-saving technologies for processing ingot, powder, and nanocomposite materials with different dispersion of phase and structural components that are operated under extreme conditions and states.
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Arun, C. P. "Threads, objects and the tapestry of the mind." European Psychiatry 26, S2 (March 2011): 1192. http://dx.doi.org/10.1016/s0924-9338(11)72897-8.
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The brain is essentially a multiprocessor computer employing large-scale multithreading. Extending previous work, (Arun, C.P. European Psychiatry 2009 and 2010) we examine whether process threads and objects can simulate diverse mental illnesses. We used Java 6, an object oriented programming language to simulate thread and object generation in the mind. Process threads were programmed to allow control of(1)the clock speed’ of the brain's internal clock(2)duration of thread life and efficiency of garbage collection’(3)integrity of internal objects and(4)assignment of salience.A few examples of the results are mentioned here. A fast clock speed led to the rapid generation of threads causing a rapid switch from one task/topic, manifesting among others, as a shortened attention span and flight of ideas (mania). Slow thread formation led to psychomotor agitation as well as a slow rate of speech output (depression). Failure to reign in (’garbage collect’) threads caused them to persist and led to many short and recurrent thoughts/actions (as in anxiety). Disordered weighting of threads and/or damage to objects led to the assignment of salience inappropriately (the hallmark of the psychoses). The failure to generate enough threads (’ loss of multithreading’) led to problems with complex tasks (like ability to recognise facial cues) and recurrent thread generation without variety, led to repetitive behaviour, hyperstimulation, etc (autism spectrum disorders). Studying Threads and Objects as integral parts of the computational Tapestry of the Mind provides rich insights into mental functions in health as well as illness.
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Sevost'yanov, P. A., and M. L. Tikhomirova. "FRICTION AMONG THE THREADS OF WEAVING FABRICS DURING THEIR ELONGATION." Technologies & Quality, no. 3 (2019): 22–26. http://dx.doi.org/10.34216/2587-6147-2019-3-45-22-26.
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The article analyses the role of friction between the warp and weft threads in the canvas. A mathematical model of the influence of friction forces on the elongation of the main thread and the mutual displacement of the warp and weft threads in plain weave is proposed. The features of the dynamics of the propagation of deformation along the warp threads as a result of the influence of friction forces are established. It is shown that at low friction forces between the warp and weft threads, the system behaves as a two-point quasilinear oscillator, the movement of which is a beat with oscillations at the fundamental and combined frequencies. With an increase in the friction forces, the randomness of motion in the places where the filaments overlap increases and with a further increase in their vibrations, the vibrations disappear, the fabric structure behaves as a whole. The calculation of the warp thread deformation taking into account the friction forces against the weft thread showed that the friction forces significantly affect the displacements of the thread sections when it is elongated, and the effect of chaotisation of the shift of the thread sections, which is certainly transmitted back to the weft threads, arises.
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Sadr, Katayoun, and Seyyed Mahdi Vahid Pakdel. "A 3-D finite element analysis of the effect of dental implant thread angle on stress distribution in the surrounding bone." Journal of Dental Research, Dental Clinics, Dental Prospects 16, no. 1 (May 29, 2022): 53–61. http://dx.doi.org/10.34172/joddd.2022.009.
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Background. This study aimed to evaluate the effect of an increase in fixture thread face angle on the amount and distribution of stresses in the surrounding bone of implants with four different thread shapes by three-dimensional finite element analysis. Methods. Eight different fixture designs, with v-shaped, buttress, reverse buttress, and trapezoid threads, and two face angles of 20 and 35 degrees, were modeled using a software program. Each model was affected by two static forces with different values and angles (200-N axial 0° force and 100-N 45° oblique force) to compare the distribution of stress in different fixture designs. Results. The maximum von Mises stress was detected in v-shaped threads. An increase in the angle of the threads to 35° significantly decreased maximum von Mises stress in cortical bone in v-shaped and reverse buttress threads; however, the von Mises stress in the trapezoid and buttress threads increased with an increase in the thread angle. Conclusion. Under the limitations of this study, although the shape of the thread and thread surface angle does not have a definite role in stress distribution in the bone surrounding the implant, they are effective in the amount and type of stress induced in the bone supporting the implant.
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CHAILLOUX, EMMANUEL, VIVIEN RAVET, and JULIEN VERLAGUET. "HIRONDML: FAIR THREADS MIGRATIONS FOR OBJECTIVE CAML." Parallel Processing Letters 18, no. 01 (March 2008): 55–69. http://dx.doi.org/10.1142/s0129626408003223.
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In this paper, we present HirondML, an Objective Caml library implementing migrating threads. Our library is based on a simplified implementation of the Fair Threads, a reactive threads system originally developed at INRIA. The Fair Threads scheduling policy is based on mixing cooperative and preemptive threads. We designed a thread migration system based on the cooperativeness of Fair Threads. To minimize data copying, we adopted an original rebinding policy distinguishing local variables, which are copied, from global variables, which are rebound when a migration takes place. Such a choice allows two styles of programming, by copy or by sharing. This will be illustrated by different distributed applications.
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Kang, Minsuk, Yong Seok Nam, In Jong Kim, Hae-Yeon Park, Jung Ryul Ham, and Jae Min Kim. "A Cadaveric Study of Thread Cubital Tunnel Release with Newly Developed Threads." Journal of Korean Neurosurgical Society 65, no. 2 (March 1, 2022): 307–14. http://dx.doi.org/10.3340/jkns.2021.0135.
Full textAbstract:
Objective : The percutaneous thread transection technique is a surgical dissecting method using a dissecting thread inserted through a needle under ultrasound guidance without skin incision. As the new dissecting threads were developed domestically, this cadaver study was conducted to compare the effectiveness and safety between the new threads (ultra V sswire and smartwire-01) and a pre-existing commercial dissecting thread (loop & shear) by demonstrating a modified looped thread cubital tunnel release.Methods : The percutaneous cubital tunnel release procedure was performed on 29 fresh cadaveric upper extremities. The preexisting commercial thread was used in 5 upper extremities. The two newly developed threads were used in 24 upper extremities. Two practitioners performed the procedures separately. After the modified looped thread cubital release, anatomical and histological analyses were performed by a blinded anatomist. The presence of the dissected cubital tunnel and damaged adjacent soft tissue was assessed.Results : Out of the 29 cadaveric upper extremities, 27 specimens showed complete dissection of the Osborne ligament and the proximal fascia of the flexor carpi ulnaris muscle. One specimen was incompletely dissected in each of the ultra V sswire and smartwire-01 groups. There were no injuries of adjacent structures including the ulnar nerve, ulnar artery, medial antebrachial cutaneous nerve, or flexor tendon with either the commercial thread or the newly developed threads. The anatomical analysis revealed clear and sharp incisional margins of the cubital tunnel in the Smartwire-01 and loop & shear groups. All three kinds of threads maintained proper linear elasticity for easy handling during the procedure. The smartwire-01 provided higher visibility in ultrasound than the other threads.Conclusion : The newly developed threads were effective and safe for use in the thread cubital tunnel release procedure.
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SHCHERBAN, V., A. PETKO, O. KOLISKO, Y. SHCHERBAN, and L. HALAVSKA. "SOFTWARE MODULES AND PROCEDURES OF A COMPUTER PROGRAM FOR DETERMINING THE TENSION OF A KEVLAR THREAD WHEN KNITTING USING A RECURSOR ALGORITHM." HERALD OF KHMELNYTSKYI NATIONAL UNIVERSITY 295, no. 2 (May 2021): 271–74. http://dx.doi.org/10.31891/2307-5732-2021-295-2-271-274.
Full textAbstract:
Improving the process of knitting fabrics from Kevlar complex threads on flat knitting machines is to create the minimum necessary tension in the area of formation of the knitted fabric. To ensure this, it is necessary to determine the change in relative tension in the refueling zones of Kevlar complex threads on flat knitting machines. These zones are formed by arranging the thread guides, tension compensation devices, tension devices and thread break control devices in the working area of the supply system to form a spatial filling line for each specific knitting machine. This complex task for flat knitting machines should be based on the use of specially designed computer programs. Given the specifics of processing Kevlar complex threads on flat knitting machines, when determining the relative tension in each zone, it is necessary to use a recursion algorithm, when the output tension of Kevlar complex threads from the previous zone will be the input for the next zone. When determining the tension of Kevlar complex threads, their interaction with the guides of Kevlar complex threads, tension compensation devices, tension devices and devices for controlling the breakage of Kevlar complex threads, it is necessary to take into account the value of Kevlar complex thread diameter, its physical and mechanical properties, deformation, deformation the coefficient of bending stiffness when determining the actual angle of coverage of the guide surface. Ensuring the minimum necessary tension in the area of formation of the knitted fabric will allow to obtain the parameters of the loop structure of property and tactical equipment of servicemen capable of protecting the human body from fire, cold, cutting, barbed weapons, shock and shotgun impact. Minimizing the tension in each zone of the line of Kevlar complex threads on flat knitting machines will reduce the probability of breakage, which is important for improving knitting processes from the standpoint of improving the productivity of flat knitting machines and product quality. Mathematical support of a computer program requires the development of models of thread guides, tension compensation devices, tension devices and thread break control devices, taking into account the real physical and mechanical properties of Kevlar complex threads and real geometric and structural parameters of structural elements of the feed system.
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Duan, Zhi Dong, Jun Feng Gao, and Tie Ming Su. "Investigation into the Effect of the Nut Thread Cutting on the Stress Distribution in a Bolt Using the Finite Element Method." Advanced Materials Research 148-149 (October 2010): 99–102. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.99.
Full textAbstract:
In order to abate fatigue fracture at roots of the first or the second hackle thread of bolt used for hydraulic press ,law of stress and load distribution in bolt threads suffered the axial forces were researched by using nonlinear finite element method.It was found that Peak equivalent stress in roots near axial force are abviously greater than these far away axial force when nut threads are in elastic range,but almost are equial to stress in roots far away axial force when 70% nut threads are in plastic region.Nut thread cutting to the fisrt two teeth can improve stress distribution in a bolt ,but these improvement recede quickly as plastic rigions of nut threads extend.