Wire Fiber Research Articles

Solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles as ionophore

A novel solid-contact potentiometric sensor for ascorbic acid based on cobalt phthalocyanine nanoparticles (NanoCoPc) as ionophore was fabricated without any need of auxiliary materials (such as membrane matrix, plasticizer, and other additives). The electrode was prepared by simple drop-coating NanoCoPc colloid on the surface of a glassy carbon electrode. A smooth, bright and blue thin film was strongly attached on the surface of the glassy carbon electrode. The electrode showed high selectivity for ascorbic acid, as compared with many common anions. The influences of the amount of NanoCoPc at the electrode surface and pH on the response characteristics of the electrode were investigated. To overcome the instability of the formal potential of the coated wire electrode, a novel electrochemical pretreatment method was proposed for the potentiometric sensor based on redox mechanism. This resulting sensor demonstrates potentiometric response over a wide linear range of ascorbic acid concentration (5.5 × 10 −7 to 5.5 × 10 −2 M) with a fast response (<15 s), lower detection limit (ca. 1.0 × 10 −7 M), and a long-term stability. Furthermore, microsensors based on different conductors (carbon fiber and Cu wire) were also successfully fabricated for the determination of practical samples.

Adhesion of epoxy-thermoplastic and polysulfone-LCP matrices to fibres

This work investigated the adhesion strength τ of the joints of polymer blends with fibres. Blends of polysulfone with LC-polyether and epoxy resin (based on DGEBA) with polysulfone, polyetherimide and poly(arylene ether ketone) were taken as matrices. Steel wire, polyamide (nylon-6) and glass fibres were used as substrates. The adhesion strength was determined by the 'pull-out' technique. It was found that incorporation of LCP into polysulfone and incorporation of thermoplastics into epoxy matrix resulted in non-additive relationships between the adhesion strength and modifier (LCP or thermoplastic) content C. In the case of epoxy-polysulfone, epoxy-polyetherimide and polysulfone-LCP matrices, such τ-C dependencies were described by curves showing a maximum. Optimal (maximal) adhesion strength of the blend/fibre joints was obtained at 10 wt% of polysulfone, 15 wt% of polyetherimide and poly(arylene ether ketone) in epoxy resin and 2–5 wt% of LC-polyether in polysulfone. Possible mechanisms of the interface strength enhancement are discussed.

Clinical Validation of a Structural Porous Tantalum Biomaterial for Adult Reconstruction

Various porous coatings—most notably, those manufactured by the sintering of cobalt-chrome or titanium beads and the diffusion bonding of titanium fiber wires—have been utilized for the biologic attachment of orthopaedic implants during the past three decades1. About ten years ago, a novel porous biomaterial made from commercially pure tantalum2-5 with a unique set of physical and mechanical properties was developed. Compared with conventional porous coatings, this material possesses higher volume porosity, more freely communicating pores, a higher coefficient of friction against bone, and a lower bulk stiffness (Fig. 1). In addition, the material is structural in that it has sufficient strength to enable the manufacture of implants without the need for a supportive solid metal substrate. Fig. 1 Top, Scanning electron micrograph illustrating the three-dimensional, open-pored structure of the porous tantalum biomaterial. The inset highlights the slight microtexture on the tantalum struts that results from the manufacturing process. Bottom, Monoblock cups manufactured by partial infiltration of polyethylene into the porous tantalum shell by direct compression-molding. Previous studies have characterized the physical and mechanical properties of porous tantalum6,7. Histologic analyses of the bone and fibrous ingrowth responses to various implants in animals have indicated a propensity for rapid infiltration of porous tantalum with healing tissue and relatively rapid rates of mechanical attachment8-14. Recent cell-culture studies have characterized the osteoblastic response to commercially pure tantalum, adding further confirmation to its long history as a biocompatible elemental metal2-5,15. Porous tantalum has been utilized for a wide variety of clinical applications since 1997, including joint replacement, reconstruction following tumor resection, the treatment of avascular necrosis of the femoral head, and spine fusion. The purpose of the present study was to document the clinical results obtained with porous …

Non-linear rheology of tension structural element under single and variable loading history Part I: Theoretical derivations

The present paper concerns the macroscopic overall description of rheologic properties for steel wire and synthetic fibre cables under variable loading actions according to non-linear creep and/or relaxation theory. The general constitutive equations of non-linear creep and/or relaxation of tension elements - cables under one-step and the variable stress or strain inputs using the product and two types of additive approximations of the kernel functions are presented in the paper. The derived non-linear constitutive equations describe a non-linear rheologic behaviour of the cables for a variable stress or strain history using the kernel functions determined only by one-step - constant creep or relaxation tests. The developed constitutive equations enable to simulate and to predict in a general way non-linear rheologic behaviour of the cables under an arbitrary loading or straining history. The derived constitutive equations can be used for the various tension structural elements with the non-linear rheologic properties under uniaxial variable stressing or straining.

Bone Anchors or Interference Screws?

Background Autograft stabilization uses free semitendinosus tendon grafts to anatomically reconstruct the anterior talofibular ligament. Study aims were to evaluate the biomechanical properties of Mitek GII anchors compared with the Arthrex Bio-Tenodesis Screw for free tendon reconstruction of the anterior talofibular ligament. Null Hypothesis There are no differences in load to failure and percentage specimen elongation at failure between the 2 methods. Study Design Controlled laboratory study using porcine models. Methods Sixty porcine tendon constructs were failure tested. Re-creating the pull of the anterior talofibular ligament, loads were applied at 70° to the bones. Thirty-six tendons were fixed to porcine tali and tested using a single pull to failure; 10 were secured with anchors and No. 2 Ethibond, 10 with anchors and Fiber Wire, 10 with screws and Fiberwire, and 6 with partially gripped screws. Cyclic preloading was conducted on 6 tendons fixed by anchors and on 6 tendons fixed by screws before failure testing. Two groups of 6 components fixed to the fibula were also tested. Results The talus single-pull anchor group produced a mean load of 114 N and elongation of 37% at failure. The talus single-pull screw group produced a mean load of 227 N and elongation of 22% at failure (P < .05). Cyclic preloading at 65% failure load before failure testing produced increases in load and decreases in elongation at failure. Partially gripped screws produced a load of 133 N and elongation of 30% at failure. The fibula model produced significant increases in load to failure for both. The human anterior talofibular ligament has loads of 139 N at failure with instability occurring at 20% elongation. Conclusions Interference screw fixation produced significantly greater failure strength and less elongation at failure than bone anchors. Clinical Relevance The improved biomechanics of interference screws suggests that these may be more suited to in vivo reconstruction of the anterior talofibular ligament than are bone anchors.

Frontiers of Pulsed Magnet Design

At the K.U. Leuven Pulsed Field Laboratory, high performance coils with optimized internal reinforcement by fiber composites have been pioneered and continuously further developed. Coils made with soft copper wire and Zylon-epoxy composite have sustained fields up to 75 T. For extended service life, 75 T user coils are made with an inner section of strong micro-composite wire and an outer section of soft copper, with additional outer reinforcement. A system of axial compression has been designed that increased peak field significantly. Based on the results obtained with these coils, an outlook to possible future developments are given. This includes a discussion of new materials such as the multi-composite wire and high strength M5 fibers developed by Magellan.

Shoulder Injury ??? Football

0413 HISTORY: A 20-year-old Division 1 football tight end sustained a left shoulder injury while being tackled after a completed pass. Midway through practice, during football preseason, after catching a pass he was tackled by the defensive end. With his arms holding the ball, his shoulder adducted and his elbow at 90 degrees flexion, he sustained direct trauma to the superior-anterior aspect of the left shoulder upon impact to the grass field. He experienced severe left shoulder pain and immediately reported his symptoms to the athletic trainer. PHYSICAL EXAMINATION: Examination of the left shoulder on the sidelines revealed a dramatic prominence of the distal tip of the clavicle, and a significant shoulder droop. There was obvious tenting of the skin. There was significant tenderness over the acromio-clavicular (AC) joint area, and along the deltoid and trapezius. He was unable to perform cross-arm adduction secondary to pain. The distal end of the clavicle was strikingly hypermobile, and did not reduce with shoulder shrugging. There was a decrease in range of motion noted in all planes secondary to pain. Sensation was intact and peripheral pulses were normal. DIFFERENTIAL DIAGNOSIS: Acromioclavicular Dislocation – Type 3 Acromioclavicular Dislocation – Type 4 Acromioclavicular Dislocation – Type 5 Clavicular fracture TEST AND RESULTS: Left shoulder anterior-posterior (AP) radiograph: superiorly displaced clavicle coracoclavicular distance = 4.0 cm no fracture Left Shoulder axillary radiograph: Clavicle displaced posteriorly 2.0 cm FINAL/WORKING DIAGNOSIS: Acromioclavicular Dislocation – Type 5 TREATMENT AND OUTCOMES: Iced and immobilized with sling immediately post-injury. Surgical repair 5 days post-injury revealed that the clavicle was embedded into the trapezius muscle. The AC joint was reduced and the coracoclavicular ligaments were reconstructed with a gracilis tendon autograft from the left leg and reinforced with fiber wire. Supine rehab began 2 days post-op with left upper extremity isometrics through week 1, rhythmic stabilization added in week 2, and manual resistance within his range of motion added in week 3. Standing rehab began in week 4 with dynamic range of motion and strengthening exercises, followed by the addition of plyometrics and light weight room training in week 5. Follow-up AP radiograph 6 weeks post-repair showed a coracoclavicular distance of 1.3 cm. Light contact football practice began 6 weeks post-repair. Returned to full contact football 7 weeks post injury when he had full, painless ROM, and normal strength.

Influence of CD2 fiber on the compression in the PF-1000 facility

The paper presents the results of observations of the visible radiation, x-rays and neutrons produced during the implosion of the plasma sheath upon the deuterated fiber placed at thez-axis. The discharges were carried out in the PF-1000 facility with current amplitudes ranging 2 MA. The plasma was detected with a PIN silicon detector, two soft x-ray detectors using microchannel plates, four frame cameras operating in the visible spectral range, a visible streak camera, a time-resolved optical spectrometer, three scintillation probes for time-resolved measurements of the hard x-ray and neutron emission in the downstream, upstream and side-on directions. The neutron yield was measured with five silver-activation counters. Experiments were carried out with the implosion of the hydrogen- or deuterium-plasma current-sheath upon the CD2 fiber. Considerable decrees of the soft and hard x-rays was observed in comparison to shots without fiber. The neutron yield was zero during the implosion of the hydrogen-plasma current-sheath and it was considerably decreased (by one order) during the implosion of the deuterium-plasma current-sheath. The temperature of ≈5 eV and the electron density of ≈1025 m−3 were evaluated from intensities of the CIII- and CIV-lines. These results were different from those obtained during the experiments with implosion of deuterium-plasma current sheath on the C fiber or Al wire, which were performed earlier. At the similar conditions the decrease of the x-rays and neutrons was not observed.

Modification of epoxy resin by polysulfone to improve the interfacial and mechanical properties in glass fibre composites. II. Adhesion of the epoxy-polysulfone matrices to glass fibres

Adhesion of epoxy-polysulfone (PSF) matrices to glass fibres of 12–30 μm in diameter was studied under both quasi-static and cyclic loadings. A pull-out technique was used for adhesion measurement. It was shown that incorporation of PSF into epoxy resin changed its adhesion to fibres. A maximum was observed in the adhesion strength vs. PSF content dependence at 10 wt% thermoplastic concentration. The results obtained were compared with the data on the epoxy-PSF matrices adhesion to thick steel wire (d = 150 μm) and Nylon-6 fibres (d = 250 μm). Similar values of the adhesion strength increase (22–25%) confirmed that all the changes at the interface were connected primarily with the matrix. A new preferably non-destructive cyclic loading technique was used to test the systems under cyclic loading at varying force amplitudes, frequencies and displacement amplitudes. In this technique the interphase behaviour is characterised by two variables: by the phase angle between the deformation applied to the matrix and the force transferred by the matrix to the fibre, and also by the amplitude of this force. Minimal force amplitudes were observed for the joints with 10 wt% polysulfone. Moreover, phase-angle values for epoxy-10% polysulfone joints were minimal among all the systems investigated. Increase in the number of loading cycles caused much more damage to unmodified epoxy matrix than that to epoxy-polysulfone matrices. Thus, modification of epoxy resin by polysulfone enhanced its adhesion to fibres under both quasistatic and cyclic loadings, especially for epoxy-10% polysulfone matrix. The possible mechanism of the phenomenon observed is discussed.

Effects of yarn constitutions and fabric specifications on electrical properties of hybrid woven fabrics

Abstract This paper reports a fabrication method for conductive open-end friction core-spun yarn (OFCY), which, as described, are constructed from open-end friction spun yarn (OFSY) and core stainless steel wire (SW) combined within the yarn twisting zone of the friction drum during the open-end friction spinning process. To facilitate weaving of SW and reduce the material cost, initially, the sheath stainless steel (SS), Kevlar (KS) or rayon (RS) staple fiber and core stainless steel wire are combined to form the OFCY yarn by using a DREF III open-end friction spinning method. The OFCY yarns were successfully woven into a variety of woven structures produced from a semi-automatic loom. The primary objects of this research are to develop new conductive yarns and fabrics, which could be suitable for shielding home electronic devices, electrical appliances from electromagnetic fields. Such fabrics could be incorporated into prepreg systems used for composite manufacture. In these fabrics, SW is used as a core component that is wrapped around a sheath SS and KS or RS to form an OFCY yarn in which OFCY yarn strength remains the same and electrical properties are better than for an equivalent OFSY yarn. Stainless steel staple fibers (SS) and wire (SW) are incorporated as conductive fillers to enhance the electromagnetic shielding properties of the woven fabric. The electromagnetic shielding effectiveness (EMSE) of various woven fabrics was obtained using a coaxial transmission line holder in the frequency range of 300 kHz–3 GHz. The variations of EMSE, the surface and volume resistivities of the woven fabric structure, and blend ratios of the OFCY yarns are also described.

434 形状記憶 TiNi ワイヤを用いたトラス橋モデルの制振効果

In this paper, the characteristics of active vibration control for the truss bridge model was investigated by using shape memory TiNi fiber wire. An experimental study was carried out to investigate the effect of compressive stress in the floor and the truss caused as well as performances of active vibration control by shape recovery of pre-strained TiNi wires when impressing direct electrical current heating. The vibration responses and damping behavior are measured by electric strain gages and an accelerometer. This demonstrates the effect in the warp decrease in the alcove slab in the diagonal part though he warp increases. It is confirmed from the measured diagonals that active vibration control for the bridge model effective in a specific frequency under the vibration load.

Transverse heated filter atomizer: the first approximation to the model of vapor transport

The transverse heated filter atomizer (THFA) provides substantial advantages in trace element determination, due to the efficient suppression of interferences. This advancement is determined by the THFA design and the properties of its components: the pyrocoated graphite tube, the sample collector (carbon fiber and refractory wire) and the graphite filter.

Practical data communications

From the Publisher: This book serves the practitioner. Its wide discussion of data network enhancements and design is built upon a thorough introduction of generic and specific data networks, focusing at length on transmission limitations, protocols and how they work, and questions of standards and related topics. The book covers local area networks (LANs) based on IEEE and ANSI standards, and wide area networks (WANs) built around TCP/IP, SNA, and OSI related protocols. It also covers VSAT (very small aperture terminal) satellite networks for data connectivity, and frame relay and SMDS for the interconnection of LANs over long distances. The reader will share the benefits of the author's extensive experience, detailing actual implementation methods for enterprise networks, considering particular corporate and government requirements, describing wiring concepts and specific models, and providing comparisons between different systems in terms of performance and complexity. Throughout, data communication is incorporated into the bigger picture of telecommunications, including the public switched digital network (PSDN), questions of high-capacity transmission media such as fiber optics, wire pair, and microwave and satellite communications. There is emphasis on the trend toward the integration of data, voice, and image into a single telecommunication system - popularly termed multimedia communications.

Design and implementation of a QoS oriented data-link control protocol for CBR traffic in wireless ATM networks

This paper presents a QoS oriented Data Link Control (DLC) framework for transporting Constant Bit Rate (CBR) traffic over wireless ATM links. Data link control is usually omitted in fixed ATM networks because cell corruption due to channel error is extremely rare for reliable media like copper wire and optical fiber. However, for wireless, higher bit error rates are quite common due to shadowing and other fading effects. The purpose of DLC in wireless is to provide error-free transport to the higher layers by recovering corrupted cells at the link layer. A selective reject (SREJ) automatic repeat request (ARQ) based DLC protocol is used for CBR error recovery. For an ARQ based scheme, higher recovery rates can be achieved with larger cell transfer delay, caused by cell retransmissions. Since cell transfer delay and DLC recovery rate both translate to user-perceivable Quality-of-Service (QoS), it is important for the DLC to strike a balance between these two, depending on the application's requirements. To achieve this in our protocol, the retransmission procedure for a CBR cell is constrained to complete within a recovery time interval which is specified by the application at call-setup time. Also, a novel jitter removal scheme that reduces the cell delay variation caused by cell loss and retransmissions, is incorporated as a part of the DLC protocol. The proposed protocol is implemented on NEC's WATMnet prototype system. The implementation and its experimental results are reported for illustrating the performance and feasibility of the presented CBR DLC protocol. The experimental results show that the DLC protocol can be successfully applied for QoS-constrained error recovery of CBR traffic on a per-connection basis. These also indicate that the DLC can be programmed to attain a desirable tradeoff between cell transfer delay and cell recovery rate.

ADHESION BETWEEN EPOXY-POLYSULFONE BLENDS AND FIBERS

The adhesive strength of a fiber-polymer interface is determined, where epoxy resin blends and linear heat-resistant thermoplastics - polysulfone (PSF) and polyetherimide (Ultem) - are used as matrices. Steel wire and polyamide (nylon-6) fibers are taken as reinforcing fillers. It is shown that the addition of PSF to epoxy resin results in a maximum on the concentration curve corresponding to a 10% PSF content. It is also found that the adhesive strength of the ED-20+Ultem-steel wire interface is practically independent of the modifier content under low (up to 10%) Ultem concentrations.

Defect detection systems for enameled copper wire, cable, and optical fiber: state of the art and current trends

International competition among copper wire suppliers increased the demand for automatic surface inspection equipment. The authors critically review a range of existing surface inspection techniques and describe preliminary results on a new system.

Adhesive strength in the interaction of polyamides with aramid fibres

Wetting of organic fibres by polyamide melts was investigated. On the example of Terlon, it was shown that the contact angle of wetting increases in the order PA-610 < PA-6 < < PA-12. The polymers are also in the same order in wetting of a steel wire. Adhesion on the interface was investigated in the same systems. PA-610 in the form of powder exhibited maximum adhesion to steel wire and organic fibres. The necessity of using highly viscous matrices in the form of finely disperse systems for obtaining reliable and reproducible adhesive strength values was demonstrated. The validity of using steel wire as a model substrate was demonstrated and the qualitative characteristics of the change in the adhesive strength under the effect of factors which primarily alter the properties of the polymer matrix were found. The results obtained in studying the shear strength of the composites are correlated with the results of determining the adhesive strength in their unit cell. This allows recommending the shear method for evaluating adhesion in industrial conditions.

Smart Composite Biomaterials TiAIV/AI2O3/TiNi

ABSTRACTThe TiNi shape memory alloy wires were plasma coated by α-Al2O3 ceramics and afterwards they were cast into Ti6Al4V or Ti6Al1.5V2.5Nb (Ti-alloy) matrix. The wire fibers melt and the alumina ceramics reacts with both TiNi and Ti-alloy if cooling rate is small. The interphases which are formed are Ti2(Al, Ni) and Ti3AL-type phases, respectively. The structure of TiNi wires changes to dendritic one, Ti-alloys contain 10 to 15% of primary α and transformed β phase. The optimal conditions for rolling are 900°C with reductions of 5%. At this conditions all the constituents of composite material can be deformed plastically. The adhesive strength of TiNi/Al2O3 is 60 MPa.

Smart Structural Composites with Monofilament, Piezoelectric Sensors

Smart materials or structures have embedded sensors to monitor their own state as well as environmental stimuli. A novel sensor was developed by sputtering a piezoelectric film onto a conductive fiber or metal wire. This sensor, similar in configuration to an optical fiber, is active since an electric field is developed when strained. Several of these sensors were embedded into a cantilevered beam and a filamentwound cylinder made from AS4/ Epon 828 composites. A variety of test cases were used to demonstrate its sensing feasibility, including free and forced vibrations and acoustic emissions.

Micron-size particle filtration with dual wire artificial electret fibers

The authors present the construction, operation, and test results of a new type of electrostatic filter of very low pressure drop at usual flow-through velocities while providing excellent filtration for micron-size particles. The filter is constructed in the form of a thick mesh of dual wire fibers, electrically energized at approximately 200 V DC, and reversing the polarity at a very low frequency in the order of 5 mHz. While, in general, mechanical filters trap the particles on the air incoming surface, with subsequent rapid "blinding," the new filter collects the particles inside the mesh volume thus offering a considerably longer life.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>