Kinds Of Threads Research Articles

A novel ultrashort dental implant design for the reduction of the bone stress/strain: A comparative numerical investigation

Nowadays dental implant surgery is a very diffused technique with a high probability of success. Nevertheless, undesirable events such as the failure of the implant, and in many cases, the loss of the prosthesis can occur, due to the external imposed conditions. The design, the shape and geometry of the implant, the material, the kind of thread and so on, become therefore crucial variables for a longer prosthesis life cycle. This paper aims to investigate in terms of stress/strain by using Finite Element Method (FEM) a novel implant design, with thick shape, length<5 mm and diameter/length ratio>1, in comparison with a classical design implant, characterized by a narrow shape, length >5 mm and diameter/length ratio<1. Both the systems are made of titanium grade V -Ti-6Al-4V- and are coupled with dental bone which was modeled by a cortical and cancellous parts with specific mechanical properties. Results in terms of pressure field were presented for various boundary conditions imposed, and for different zones of the bone, implant and sectioned regions. The results allowed us to demonstrate the improved mechanical behavior of the biomechanical coupling implant/bone when the proposed design is adopted. Indeed, the stress/strain distribution of the implant, together with the deformations, resulted more uniform with lower peaks for all the considered boundary conditions. Analogously, the strain and the deformations followed the same trend.

On-site testing of sutured organs: An experimental set up to cyclically tighten sutures

A number of surgical practices are aimed to compensate for tissue relaxation or weakened/atrophied muscles by means of suture prostheses/thread lifts. The success rate of these procedures is often very good in the short term, while it is quite variable among subjects and techniques in the middle-long term. Middle-long term failures are mostly related to suture distraction, loosening or wear, coming from repeated loading cycles.In this work, an experimental device to perform ex vivo tests on prosthetic sutures has been set up. An equine laryngoplasty has been used as a benchmark, being representative of sutures aimed to compensate for atrophied muscles. The peculiarity of this experimental set up is that the suture is on-site and it has been tightened with known, repeated loads, which do not depend on thread deformation at different load levels. Preliminary tests have been performed applying over 3000 load cycles and finally a tensile test up to rupture.Force/displacement curves obtained with this experimental set up have been reported and parameters useful to classify the biomechanical performance of sutures versus time (mainly its creep behaviour), have been outlined.Results have outlined that the organ-suture system undergoes significant creep over 3000 cycles, and this should be taken into account in order to foresee its long-term behaviour; in addition, the suture anchorage to cartilage should be improved.The experimental set up can be used to perform on-site testing of sutures, taking into account the compliance and creep response at both suture anchorage ends, in order to compare different surgeries and different kinds of thread.

Study on Change of Chromium Plating Thickness of Threads of Control Rod Drive Mechanism of Nuclear Power

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.

Design Principles for Knitted Items with Bicomponent Cloths

The properties defining the target purpose of functional clothing in addition to the construction and external appearance requirements are dominant factors in its fabrication. For example, sports apparel should even out temperature drops of the body and wick water away from it well. An analysis showed that such attire could be produced if the sides of the item were made of a different kind of thread or yarn. Items made of bicomponent cloths can economize raw material by combining different cloths in a single item. The material outlays for the items could be reduced by using bicomponent cloths in several of their parts.

The Analysis on Wall Effect After Expansion and Expandable With Threaded Performance of Single Wellbore Diameter Expandable Casing

Single wellbore diameter expandable casing technology is an important development direction of the expandable casing technology. The development and maturity of this technology will cause a revolution in drilling technology. Elastic-plastic finite element analysis of frictional contact is used to analyze the effect of geometrical deviation before expansion on casing thickness after expansion; the expansion casing thread connections expandability is analyzed, the connection status of the expanded general casing thread is simulated, then based on the study above, one kind of thread which is suitable for the single wellbore diameter expandable Casing connection is designed. The results for this paper provide the basis for the standardization of the expansion casing’s machining precision and the selection of connecting thread, which promote the development of single wellbore diameter expandable casing.

On selves, forms, and forces

Comment on Kohn, Eduardo. 2013. How forests think: Toward an anthropology beyond the human . Berkeley: University of California Press.

STUDY ON TUBE SHELL TRANSVERSE DISPLACEMENTS UNDER ITS MACHINING BASED ON COMPUTER SIMULATION

The possibility to increase parameter accuracy (pitch of thread, pressure angle, external and internal thread diam eter) for various kinds of thread on the seamless casing is studied. As a means of achieving the targ et goal, the v ibration amplitude contraction arising in the system ‘machine — widget — tool — part’ is considered (MWTP). To solve the problem, a model which describes tube shell oscillations in the course of its processing a nd allows defining the impact on the work end of shell oscillations arising in its loose part is offered. The study is resulted in a math ematical model b ased on the initial parameters method. The calculations found the best (of the considered in the paper) support location diagram under which the arising oscillations are the lowest. The obtained re sults can be used at any enterprise dealing with thread cut ting on the casing tubes. The investigation results in the following: — optimum quantity of supports for the considered equipment is five; — expansion in the number of supports by no means always leads to the vibration amplitude contraction; — changing in the relative position of supports is an effective means of the vi bration amplitude contraction that acts to increa se thread parameters accuracy.

Study on the Wool-Solospun Spinning Technology

Solospun spinning is a new type of wool-spinning methods, Solospun spinning technology principles and characteristics were introduced in the paper, the domestic-manufacture fluted Roller was used on the existing equipment and the production was carried on,In addition to comparing with the traditional ring spinning production ,the structure and performance of two kinds of threads had been tested ， the yarn comprehensive performance judgement was also given.it was proofed that the solospun-spinning yarns was better than the ring spinning yarns.

Load Distribution Balance Principle of Petroleum Buttress Casing Thread and its NC Machining Method

The force of each API standard buttress casing thread teeth under axial tension is uneven, so the bearing capacity of this kind of thread is seriously restricted. On the basis of structural characteristics, mechanical model of the casing thread under axial tension is established and the loading and deforming features of thread teeth are analyzed. Based on this, to improve force distribution of casing thread, the designing method of multi-segment variable pitch thread is put forward and NC machining method of variable pitch thread with equal tooth thickness is presented.

Lagrangian modeling and analysis of the dynamics of frictional winding mechanisms

This paper investigates the dynamics of frictional-type winding mechanisms widely used in textile industry. The mechanism under study is used to wind various kinds of thread onto bobbins of cylindrical form. The system essentially consists of a motor-driven cylinder which is pressed to a cylindrical bobbin hence bringing the latter into rotation through friction between the two surfaces. A textile thread is supplied into the contact zone and winds around the bobbin. For the winding operation to proceed accurately, the winding mechanism must be free of vibrations to ensure a constant and reliable contact zone.

Thread as a Matrix for Biomedical Assays

This paper describes the use of thread as a matrix for the fabrication of diagnostic assay systems. The kinds of thread used for this study are inexpensive, broadly available, and lightweight; some of them are already familiar materials in healthcare. Fluids wick along these threads by capillary action; no external power source is necessary for pumping. This paper demonstrates three designs for diagnostic assays that use different characteristics of the thread. The first two designs-the "woven array" and the "branching design"-take advantage of the ease with which thread can be woven on a loom to generate fluidic pathways that enable multiple assays to be performed in parallel. The third design-the "sewn array"-takes advantage of the ease with which thread can be sewn through a hydrophobic polymer sheet to incorporate assays into bandages, diapers and similar systems. These designs lead to microfluidic devices that may be useful in performing simple colorimetric assays that require qualitative results. We demonstrate the function of thread-based microfluidic devices in the context of five different colorimetric assays: detection of ketones, nitrite, protein, and glucose in artificial urine, and detection of alkaline phosphatase in artificial plasma.

水中を動く網地が受ける水の抵抗-IV

Since synthetic fiber was adopted for fishing nets, many problems have given rise due to its different properties from natural fiber. Among them there is configuration of the nets which is affected by currents more than that of natural fiber nets because threads of synthetic fiber such as Amilan or Vinylon are smaller in specific gravity. For a preparatory study of the configuration of nets, tests have been carried out to clarify different inclinations of various threads in a current. In addition, experiments have been conducted on dyeing treatments of synthetic fiber threads for the purpose of decreasing the inclination, using dyeing materials such as coal-tar or its mixtures prepared with a commercial stone-powder, 15-, 30-, 45-percent in weight of the coal-tar base. Specification of the threads used for experi-ment is shown in Table 1. Keeping one end of the threads, each 130 centimeters long, on the water level, the vertical distance h from level to the other end was measured under current speed v. From Fig. 1 showing the relationship between v and h, it is noticed that the thread inclination denoted by h becomes larger as the diameter of thread d increased or coal-tar dyeing is used. Fig. 2 shows the comparison of h of various kinds of threads within almost the same value of d, and Fig. 3 the relationship between d and h by kind of threads, when current flows at 15 centimeter per second. From these figures, the thread inclination are obtained, in increasing order as Saran, cotton, manila- twine, Amiran, Vinylon; and in case of no dyeing, h of Vinylon is 40 to 60 percent, and Amilan 60 to 75 percent, of the inclination of cotton hc. However, in coal-tar dyeing, the difference decrease nearly to 10 percent. Different inclinations of threads due to dyeing treatments are given in Figs. 4 and 5. By coaltar dyeing, Vinylon is most effectively decreased in the thread inclination. -From Fig. 6 indicating the forces acting on thread in a current, next formula may be led Pθ=ω•cos θ. Taking the resistance coefficient Cp, the resistance Pθ is expressed by Pθ=σ/2g• d•Cp•v2 Where σ is the specific gravity of water, and g the acceleration of gravity. Hence, Cp=cosθ/v2 bull;2g/σ•ω/d. In order to decrease the inclination of thread, i.e., to increase the value of θ, it is desirable to make values of Cp as small and ω/d as large as possible. On the base of the values of Cp for tested threads (Figs. 8, 9), it is obvious that Vinylon is the largest in the value, and Amilan the least, in case of no dyeing. Whereas, in coal-tar dyed threads, Cp of Vinylon thread decreases almost to the same as of Amilan. On the other hand, in regared with the increasing ratio of ω/d by dyeing, Amilan is the largest followed by Vinylon (Table 2). Thus, the fact that Vinylon is remarkable for decreasing Cp, and Amilan for increasing ω/d, in coal tar dyeing, has led to a conclusion that the dyeing applied to these two kinds of threads is efficient for decreasing the thread inclination by current.

所謂楔状欠損の観察とその成因に関する実驗的研究 (3)

1. Generally speaking the rubbing is an indispensable factor to cause a so-called cuneiform defect. This defect occuring on the enamel, however, is caused not only by rubbing but by acquired decalcification, process of dental caries and congenital reduction of resistance, such as less calcification. On the other hand, that on the cervical area is mainly due to rubbing and decalcification by acid or dental caries plays a smaller part in this case.2. Principal cause of the cuneiform defect is the use of tooth-bruch and tooth-powder, especially being concerned in the quality of the latter.3. So-called cuneiform defect occurs by all sorts of movement of tooth-brush, such as vertical, horizontal and round movement, but above all the effect of horizontal movement is important.4. Furthermore it can be noticed by the other causes: fingertip and tooth-powder, salt, toothpick, the margin of dental plate, clasp of dental plate, raw vegetables, fruits, and all kinds of thread.5. The degree and the form of so-called cuneiform defect have some connection with force, direction and working period of rubbing, quantity of applied tooth-powder, size and strength of the brush, width of the exposed root surface, hardness of the tooth-root and speed of the gingival atrophy.

水中を動く網地が受ける水の抵抗 (I)

Since synthetic fiber was adopted for fishing nets, many problems have given rise due to its different properties from natural fiber. Among them there is configuration of the nets which is affected by currents more than that of natural fiber nets because threads of synthetic fiber such as Amilan or Vinylon are smaller in specific gravity. For a preparatory study of the configuration of nets, tests have been carried out to clarify different inclinations of various threads in a current. In addition, experiments have been conducted on dyeing treatments of synthetic fiber threads for the purpose of decreasing the inclination, using dyeing materials such as coal-tar or its mixtures prepared with a commercial stone-powder, 15-, 30-, 45-percent in weight of the coal-tar base. Specification of the threads used for experi-ment is shown in Table 1. Keeping one end of the threads, each 130 centimeters long, on the water level, the vertical distance h from level to the other end was measured under current speed v. From Fig. 1 showing the relationship between v and h, it is noticed that the thread inclination denoted by h becomes larger as the diameter of thread d increased or coal-tar dyeing is used. Fig. 2 shows the comparison of h of various kinds of threads within almost the same value of d, and Fig. 3 the relationship between d and h by kind of threads, when current flows at 15 centimeter per second. From these figures, the thread inclination are obtained, in increasing order as Saran, cotton, manila- twine, Amiran, Vinylon; and in case of no dyeing, h of Vinylon is 40 to 60 percent, and Amilan 60 to 75 percent, of the inclination of cotton hc. However, in coal-tar dyeing, the difference decrease nearly to 10 percent. Different inclinations of threads due to dyeing treatments are given in Figs. 4 and 5. By coaltar dyeing, Vinylon is most effectively decreased in the thread inclination. -From Fig. 6 indicating the forces acting on thread in a current, next formula may be led Pθ=ω•cos θ. Taking the resistance coefficient Cp, the resistance Pθ is expressed by Pθ=σ/2g• d•Cp•v2 Where σ is the specific gravity of water, and g the acceleration of gravity. Hence, Cp=cosθ/v2 bull;2g/σ•ω/d. In order to decrease the inclination of thread, i.e., to increase the value of θ, it is desirable to make values of Cp as small and ω/d as large as possible. On the base of the values of Cp for tested threads (Figs. 8, 9), it is obvious that Vinylon is the largest in the value, and Amilan the least, in case of no dyeing. Whereas, in coal-tar dyed threads, Cp of Vinylon thread decreases almost to the same as of Amilan. On the other hand, in regared with the increasing ratio of ω/d by dyeing, Amilan is the largest followed by Vinylon (Table 2). Thus, the fact that Vinylon is remarkable for decreasing Cp, and Amilan for increasing ω/d, in coal tar dyeing, has led to a conclusion that the dyeing applied to these two kinds of threads is efficient for decreasing the thread inclination by current.