Flexible Cord Research Articles

INCREASING THE RESOURCE OF VEHICLE PARTS BY COMPOSITE MATERIALS DURING THEIR RESTORATION REPAIR

To restore machine parts used quite a large range of materials in the form of wire, powders, flexible cords, etc. However, it is not always possible to provide the required resource for the restoration of parts working in abrasive and corrosive environments. One of the modern directions of increasing the wear resistance and other properties of reducing coatings is the use of composite materials. This paper presents the results of research on the development of a composite modifying material to control the properties of reducing coatings based on commercially available powder material PG- 10N-01. It is shown that the developed composite material obtained using the SHS process from a powder mixture of Ti+C+SiO2+Al2O3+Fe2O3+Al+PT-NA-01 provides a higher (1.65 times) abrasive resistance of the deposited alloy coating PG-10N-01 when modifying its composite material in the amount of 20%.

Smart Plug 2.0: A Solid-State Smart Plug Device Preventing Fire and Shock Hazards

Electrical faults cause fire or shock hazards in homes and offices. Flexible power cords are particularly susceptible to metal or insulation degradation that may lead to a variety of electrical faults. This article introduces a new Smart Plug 2.0 device which offers all-in-one protection against short-circuit, overload, arc, and ground faults in addition to the wireless power control and monitor function of conventional smart plug devices. It offers microsecond-scale time resolution to detect and respond to a fault condition, and significantly reduces the electrothermal stress on household electrical wires and loads. A new arc fault detection method is developed using machine learning models based on load current <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">di/dt</i> events. Comparing to other solid-state circuit breaker designs which typically respond to overcurrent conditions only, Smart Plug 2.0 integrates additional protective functions into the same hardware structure with minimal cost penalty. A 120 V/10 A solid-state Smart Plug 2.0 prototype using power <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">moseft</small> s is designed and tested. It has experimentally demonstrated the comprehensive protection features against all types of electrical faults.

Biomechanical Comparison between Isobar and Dynamic-Transitional Optima (DTO) Hybrid Lumbar Fixators: A Lumbosacral Finite Element and Intersegmental Motion Analysis.

Biomechanical performance of longitudinal component in dynamic hybrid devices was evaluated to display the load-transfer effects of Dynesys cord spacer or Isobar damper-joint dynamic stabilizer on junctional problem based on various disc degenerations. The dynamic component was adapted at the mildly degenerative L3–L4 segment, and the static component was fixed at the moderately degenerative L4–L5 segment under a displacement-controlled mode for the finite element study. Furthermore, an intersegmental motion behavior was analyzed experimentally on the synthetic model under a load-controlled mode. Isobar or DTO hybrid fixator could reduce stress/motion at transition segment, but compensation was affected at the cephalic adjacent segment more than the caudal one. Within the trade-off region (as a motion-preserving balance between the transition and adjacent segments), the stiffness-related problem was reduced mostly in flexion by a flexible Dynesys cord. In contrast, Isobar damper afforded the effect of maximal allowable displacement (more than peak axial stiffness) to reduce stress within the pedicle and at facet joint. Pedicle-screw travel at transition level was related to the extent of disc degeneration in Isobar damper-joint (more than Dynesys cord spacer) attributing to the design effect of axial displacement and angular rotation under motion. In biomechanical characteristics relevant to clinical use, longitudinal cord/damper of dynamic hybrid lumbar fixators should be designed with less interface stress occurring at the screw-vertebral junction and facet joint to decrease pedicle screw loosening/breakage under various disc degenerations.

Corrected Mathematical Models for Motions of the Gyroscope with one Side Free Support

Abstract: The recent publications about gyroscope effects explained their physics and described them by mathematical models based on the action of forces and inertial torques of classical mechanics. This new analytical approach finally solved the old problem of the dynamic of rotating objects and showed their kinetic energy is the base of gyroscopic effects. Gyroscopic effects result from the action of the two sets of interrelated inertial torques acting about two axes. Each set contains torques generated by the centrifugal, Coriolis forces, and the change in the angular momentum. Detailed study of the inertial torque of the centrifugal force showed its expression derived with an error of mathematical processing. This error gives a less value for the angular velocity of the slow rotation of the gyroscope about one axis that cannot be measured. The angular velocity of the fast rotation of the gyroscope about the other axis is measured but remains of the same value that gives the expression of the torque with error. This manuscript presents the corrected mathematical model for the motion of the gyroscope suspended from the flexible cord.

Age-related type I collagen modifications reveal tissue-defining differences between ligament and tendon

Tendons and ligaments tend to be pooled into a single category as dense elastic bands of collagenous connective tissue. They do have many similar properties, for example both tissues are flexible cords of fibrous tissue that join bone to either muscle or bone. Tendons and ligaments are both prone to degenerate and rupture with only limited capacity to heal, although tendons tend to heal faster than ligaments. Type I collagen constitutes about 80% of the dry weight of tendons and ligaments and is principally responsible for the core strength of each tissue. Collagen synthesis is a complex process with multiple steps and numerous post-translational modifications including proline and lysine hydroxylation, hydroxylysine glycosylation and covalent cross-linking. The chemistry, placement and quantity of intramolecular and intermolecular cross-links are believed to be key contributors to the tissue-specific variations in material strength and biological properties of collagens. As tendons and ligaments grow and develop, the collagen cross-links are known to chemically mature, strengthen and change in profile. Accordingly, changes in cross-linking and other post-translational modifications are likely associated with tissue development and degeneration. Using mass spectrometry, we have compared tendon and ligaments from fetal and adult bovine knee joints to investigate changes in collagen post-translational properties. Although hydroxylation levels at the type I collagen helical cross-linking lysine residues were similar in all adult tissues, ligaments had significantly higher levels of glycosylation at these sites compared to tendon. Differences in lysine hydroxylation were also found between the tissues at the telopeptide cross-linking sites. Total collagen cross-linking analysis, including mature trivalent cross-links and immature divalent cross-links, revealed unique cross-linking profiles between tendon and ligament tissues. Tendons were found to have a significantly higher frequency of smaller diameter collagen fibrils compared with ligament, which we suspect is functionally associated with the unique cross-linking profile of each tissue. Understanding the specific molecular characteristics that define and distinguish these specialized tissues will be important to improving the design of orthopedic treatment approaches.

Flame sprayed and plasma sprayed Al2O3-TiO2 coatings

Al2O3–TiO2 coatings were received by flame sprayed of flexible cord and plasma sprayed using powder. Shown higher mechanical and tribological properties of flame sprayed coating compared plasma sprayed coating.

CHAD: Compact Hand-Assistive Device for enhancement of function in hand impairments

Hand-assistive devices are used to help post-stroke victims encumbered with hand impairments perform activities of daily living (ADL). Unlike robotic rehabilitation devices used in restricted medical conditions for designated periods, hand-assistive devices are designed to be portable and to be used for extended periods by individuals engaging in ADL. Several hand-assistive device designs have been proposed. With these, designers have focused on key elements, such as size, weight, motion profile of the fingers, and generated grip/pinch force. In this paper, we propose a unique compact hand-assistive device (CHAD) that incorporates most of these design parameters, but with less trade-offs. CHAD consists of a single unit worn on the patient’s forearm, which includes all necessary components. It is compact and does not compromise functionality. The novelty of this design can be found in the use of a unique cable-driven mechanism. This mechanism uses dual linear actuators to achieve the flexion of both the index and the middle fingers via the pull of tendon-like structures originating in two selected interphalangeal joints. This permits the numerous necessary sequences in the motion profiles of the digits. The thumb is also made able to flex with a single linear actuator. Finger extensions, in contrast, are achieved passively via adjustable flexible rubber cords joined to the dorsal side of the glove. Experimental results demonstrate that CHAD generates sufficient force and motion profiles for the comfortable execution of ADL. Additionally, CHAD produces a grip and pinch motion profile similar to that of a natural hand and does not force unwanted muscle activities.

Hierarchically structured polydimethylsiloxane films for ultra-soft neural interfaces

Abstract Long-term interfacing with neural tissue is key for the diagnosis and therapy of neurological disorder. Coatings with dedicated micro- and nanostructures have been proposed, such as gold nanowires, platinum nanostructured by electrochemical roughening, columnar and porous titanium nitride, carbon nanotubes, and conductive polymers. The performance of these coatings, however, is limited because of the mechanical mismatch between implant and neural tissue. Herein, we show that micro- and nanostructured, soft and conductive elastomer films can be obtained by depositing gold on nanometer-thin thiol-functionalized polydimethylsiloxane (PDMS) films. Additionally, microstructured polyether ether ketone (PEEK) films enable directional ordering in topology. The formation of soft and conductive PDMS films with oriented wrinkles on the macroscopic scale was controlled by the ratio between the metal/elastomter thicknesses and the depth of thermally imprinted trenches. Four-point probe measurements revealed that the electrical conductivity is one order of magnitude higher than that of recently presented hydrogel formulations. Nano-indentations proved that the submicrometer-thin conductive elastomer exhibit an average elastic modulus well below 10 MPa. This material system can be made tens of micrometers thin, and, therefore, has the potential to address several challenges of current implantable neural interfaces for the central nervous system, e.g. fabrication of softer and more flexible micrometer-thin spinal cord arrays.

Corrosion resistance of composite material deposited by tig method using flexible cord TeroCote 7888T

Corrosion resistance of composite material deposited by tig method using flexible cord TeroCote 7888T

Корозійна стійкість композиційного матеріалу, наплавленого TIG способом з використанням гнучкого шнура TeroCote 7888Т

Корозійна стійкість композиційного матеріалу, наплавленого TIG способом з використанням гнучкого шнура TeroCote 7888Т

Dynamic Scoliosis Correction as Alternative Treatment for Patients with Adolescent Idiopathic Scoliosis: a Non-Fusion Surgical Technique

Anterior dynamic scoliosis correction is an innovative non-fusion option in the treatment of patients with severe adolescent scoliosis. Growth modulation and sometimes intraoperative curve correction is achieved by convex insertion of segmental screws and a flexible polyethylene cord. The present review analyses and discusses the current literature and proposes a new treatment algorithm that is based on our own experience. Short term results are published for approximately 100 patients from different institutions. Fusion could be prevented in the vast majority of patients. Perioperative complication rate is very low but a few cases of cord rupture and overcorrection are reported. Anterior dynamic scoliosis correction has promising short term results but there is a paucity of literature and optimal criteria for the best candidate has yet to be defined.

Flexible bronchoscopy-guided vocal cord biopsy under conscious sedation : An option to surgical biopsy in special situations.

Flexible bronchoscopy-guided vocal cord biopsy under conscious sedation : An option to surgical biopsy in special situations.

Flexible bronchoscopy-guided vocal cord biopsy under conscious sedation: An option to surgical biopsy in special situations.

Introduction:Vocal cord (VC) biopsies are usually performed with rigid laryngoscopy under general anesthesia (GA). In patients with comorbidities such as cardiovascular or pulmonary disease, the risk of GA is high, with morbidity and potential mortality. We describe VC biopsy (VCB) in such a high-risk cohort, done safely and successfully with flexible bronchoscopy-VCB (FB-VCB) and conscious sedation.Methods:FB-VCB was done in two groups of patients – the first at high risk for GA due to comorbidities and the second group where VC lesions were found incidentally in the course of FB done for other reasons. FB was done with local anesthesia and conscious sedation, and the VC lesion was identified. Flexible forceps were introduced through the working channel of the bronchoscope, and the lesions were carefully sampled.Results:FB-VCB was performed in 15 patients (14 males and 1 female) with a mean age of 60.7 ± 12.1 years. Of these 15 patients, 6 patients were poor candidates for GA due to comorbidities and 9 patients had incidental VC lesions found during bronchoscopy. A diagnosis was made in 14/15 (93.3%) patients. Complications included a mild ooze and hoarseness of voice for a few days, which did not require any intervention.Conclusion:We report one of the few series of patients with VC biopsies done with FB (FB-VCB) under conscious sedation, without significant complications. It is safe and useful in high-risk patients who are poor candidates for GA, with a good diagnostic yield.

Surgical extrusion: A reliable technique for saving compromised teeth. A 5-years follow-up case report

Aim: To present a long term follow up clinical case in which a compromised anterior tooth was saved by a surgical extrusion procedure. Summary: Although different techniques have been suggested for clinical crown lengthening in the anterior zone, some of them have limitations in terms of aesthetics and procedural requirements. The current case report demonstrates how a simplified surgical extrusion procedure was successfully performed for saving a severely damaged anterior tooth; furthermore, it is possible to apply the technique described in this case using minimum and simple armamentarium like a scalpel, elevators, forceps and splinting flexible cord. Key-learning points: Saving severely compromised anterior teeth is possible by applying surgical extrusion techniques when crown-root ratio allows it. Risk of root resorption or ankylosis is minimum.

The Effect of Hand Exercise on Reducing the Symptoms in Hemodialysis Patients with Carpal Tunnel Syndrome.

Context:Carpal tunnel syndrome (CTS) is one of the most common peripheral neuropathies, and there is no consensus on the preferred method of treatment.Aims:The aim of this study is to determine the effects of hand exercise performed with a ball on symptoms and to evaluate the results in hemodialysis (HD) patients with CTS.Settings and Design:This study was conducted in patients with HD who were treated in dialysis centers and state hospitals in Turkey between 2011 and 2012.Subjects and Methods:This study included 19 patients (28 hands) that were diagnosed as CTS. For exercise treatment, a hand and finger exercise ball that consists of two parts: a foam body and flexible rubber cords was used. Patients placed their fingers through each cord, squeezed it for 1 s, and then opened their fingers against the cord for 1 s. Patients repeated this exercise for 30 s to 1 min/day.Statistical Analysis Used:The McNemar, Friedman ANOVA, and the Wilcoxon test with a Bonferroni correction were used on SPSS 20.0 software package program. P < 0.05 was considered statistically significant.Results:Results showed that recovery was performed from physical examination results, grip strength, and Boston questionnaire scores. About 21.4% of patients’ electrophysiological results were negative at the end of the 1st month and 32.1% of them at the end of the 3rd month.Conclusion:Due to the slowed progress of CTS and detection of slight improvement in evaluation parameters, this self-applicable and practical exercise can be used as an alternative treatment of mild CTS in patients with HD.

Trying out spraying modes and properties of wear-resistant flame Al2O3–TiO2 coatings fabricated using a flexible cord material

Samples of Al2O3–TiO2 coatings are fabricated by the flame spraying of a flexible cord. The influence of process parameters and composition of the sprayed material on the structure, composition, and mechanical properties of coatings is investigated. It is shown that an increase in the spraying distance and feed rate of the sprayed material leads to a decrease in their density. An increase in the concentration of the low-melting TiO2 component predetermines a decrease in the coating porosity and has no significant effect on the coating hardness. Being subjected to measuring scratching, Al2O3–TiO2 flame coatings formed with minimal porosity (Π = 3.2%) are characterized by cohesion fracture behavior and no substrate opening under an indenter load of up to 90 N. The friction factor of coatings under study varies from 0.2 to 0.78 after 2800 counterbody revolutions (44 m of the friction path). This is associated with the accumulation of fatigue cracks in the coating material and its subsequent cohesive fracture by the formation of large fragments serving as an abrasive.

A mathematical model for motions of gyroscope suspended from flexible cord

AbstractGyroscope devices are primary units for navigation and control systems in aviation and space engineering. The main property of the gyroscope is maintaining the axis of a spinning rotor, based on the principles of the angular momentum of the spinning rotor. However, the nature of the gyroscope’s acting forces and motions is more complex. The torque applied to the gyroscope generates the internal resistance and precession torques based on acting simultaneously and interdependently, namely, centrifugal, common inertial and Coriolis forces generated by the mass elements of the spinning rotor as well as changes in angular momentum. This system of internal torques based on new fundamental principles of the gyroscope theory that enabled deriving the mathematical model for the motions of a gyroscope suspended from the flexible cord, which was a most unsolvable problem. The test results of the gyroscope motions well validated the new analytical approach.

Experimental Investigation of Dynamics of Assembly with Typical Mechanical Joint

Mechanical joints have a significant influence on the dynamics of assembled structure due to its discontinuity, uncertainty, frictional contact and micro-slip along the interface. To study the effect of mechanical interface on vibration behavior of industrial product, it is necessary to capture vibration data and investigate modal properties. In order to study effects of typical mechanical joints, double plates coupled with bolted joint are manufactured. Corresponding welded specimen was also manufactured for comparison and reference. Specimens were suspended by two flexible nylon cords for a free–free boundary condition and series of modal tests were carried out. Experimental results reveal that the preload in bolted joint affects the vibration behavior of assembly greatly, and the dynamic stiffness and natural frequency could be enhanced by increasing preload values of specimen. Bolted joints give rise to more frictional damping capacity within lower preload range in this test and welded specimen shows up much higher frequency and similar damping ratio.

TRY-OUT OF SPRAYING MODES AND PROPERTIES OF WEAR RESISTANT Al2O3–TiO2 FLAME COATINGS OBTAINED USING FLEXIBLE CORD MATERIAL

Al 2 O 3 –TiO 2 -based coating specimens were obtained using the method of oxyfuel gas spraying of a flexible cord. The paper studies the influence of process parameters and composition of the sprayed material on the structure, composition and mechanical properties of coatings. It was shown that the increase in spraying distance and feed rate of the sprayed material leads to reduction in their density. An increased concentration of the low-melting TiO 2 component preconditions a decrease in coating porosity and has no significant effect on its hardness. During measuring scratching, the Al 2 O 3 –TiO 2 flame coatings formed with minimal porosity (porosity ~ 3,2 %) are characterized by cohesive fracture behavior and no substrate break up at the 90 N load applied to the indenter. The studied coatings show changes in their friction factor from 0,2 to 0,78 after 2800 counterbody revolutions (44 m of rubbing path). This is due to accumulated fatigue cracks in the coating material and its subsequent cohesive fracture through formation of large fragments that serve as an abrasive.

Intraoperative ultrasonography with a surgeon-manipulated microtransducer during robotic radical prostatectomy

Intraoperative transrectal ultrasonography during laparoscopic radical prostatectomy has been reported to lead to a reduction in surgical margin rates. However, the use of a surgeon-controlled ultrasound probe that allows for precise manipulation and direct interpretation of the image by a console surgeon has yet to be studied. The aim of the present study was to show initial feasibility using the microtransducer with 9-mm scan length controlled by the console surgeon during robot-assisted radical prostatectomy in 10 patients. The transducer is designed as a drop-in probe with a flexible cord for insertion through a laparoscopic port, and is controlled by a robotic arm with the ultrasonographic image shown as a console Tile-pro display. Intraoperative localization of the biopsy-proven cancerous hypoechoic lesion was feasible in four out of four cases. The microtransducer facilitated identification of the bladder neck as well as the appropriate level of neurovascular bundle release. Negative surgical margin was achieved in all 10 cases (100%), even though five of 10 patients (50%) had extraprostatic (pT3) disease. Recovery of erectile function and continence was encouraging. In conclusion, intraoperative ultrasound navigation using a drop-type microtransducer is a novel technique that could enhance the incremental value of the standard information.