Special Jigs Research Articles

Upgrade of the Universal Testing Machine for the Possibilities of Fatigue Tests in a Limited Mode

The object of the upgrade presented in this paper was an older analogue-based universal testing machine preferably designed for tensile testing. The objective of the upgrade was to create a new digitized measurement chain capable of also operating in the mode of simple fatigue tests with cyclic tensile stresses. The upgrade of the equipment mainly included the processes of calibration, creation of related calibration jigs, creation of transformation dependencies and digitization, creation or completion of missing parts of chain-signal conditioning modules, A/D converters, special jigs, etc., as elements of the experimental hardware. The degree of correctness of the calibration and of the transformation dependencies created was verified by regression analysis, and this was verified by simple correlation analysis. The correctness of the proposed modifications, was verified on the basis of the fatigue tests performed for cyclic loading. Thus, it was possible to design, develop and functionally verify a new measurement chain based on an older universal testing machine. Thus, a partially digitized pulsator was created for the possibility of fatigue testing in a technically or functionally limited mode, mainly for educational purposes as a temporary replacement for the order of magnitude more expensive commercially produced test systems.

An All-Arthroscopic Technique of Repairing Foveal Tears of the Triangular Fibrocartilage Complex Using a Bone Anchor-Repair Made Simple.

Traumatic foveal tears of the triangular fibrocartilage complex lead to ulnar-sided wrist pain and instability, resulting in painful motion and loss of grip strength with a severe impact on the overall function of the upper limb. Surgical repair is nothing new and has traversed through the realm of open repair to arthroscopic assisted to all arthroscopic repair techniques over the many decades, with arthroscopic repairs showing better visualization, lesser trauma, and equally favorable patient outcomes. Techniques had varied from using trans osseous tunnels to bone anchors, with or without the usage of special jigs. Here, we describe a simple and fast 3 portal arthroscopic technique of repairing the torn foveal insertion of the triangular fibrocartilage complex using a bone anchor inserted under arthroscopic and fluoroscopic guidance into the fovea. Both the dorsal and volar limbs of the triangular fibrocartilage complex are repaired arthroscopically, resulting in a strong anatomic repair resulting in a stable and pain-free wrist.

Comparative evaluation of frictional characteristics between nano coated and non coated orthodontic brackets and arch wire configuration-An experimental in vitro study.

To compare and assess the coefficient of frictional resistance between nano-coated orthodontic brackets and orthodontic archwires with conventional orthodontic brackets and archwires. In this experimental study, 128 samples were divided into 4 groups consisting of 32 orthodontic wires and brackets in each group. The samples were randomly allocated into GROUP A- ZNO nanoparticle coated archwires and brackets, GROUP B ZNO nanoparticle coated bracket and conventional archwire, GROUP C-ZNO nanoparticle coated archwire and conventional bracket, and GROUP D- conventional archwire and bracket after positioning them on special jigs frictional resistance was studied and evaluated. Bon - Ferroni test was used for inter group comparison and one way ANOVA was used for intr-group comparison. The lowest mean frictional resistance is seen with Group A (nanocoated archwire with nanocoated bracket) N = 0.3401 ± 0.420; and highest with Group D (conventional brackets with conventional archwires) N = 0.8413 ± 0.60. a significant difference in mean frictional resistance was observed between the groups (P ≤ 0.01). The frictional resistance for the groups was in the following order from lowest to highest: group A < B < C < D. The study showed decreased friction in ZNO nanoparticle coated archwires and brackets than conventional archwires and brackets.

Choosing the Adhesive for Microtensile Bond Strength Tests

Abstract Dental fillings are one of the most widespread minimal invasive procedures in modern restorative dentistry. Thanks to the advantages of recently developed filling materials, adhesive systems, and filling techniques, it is possible to create high strength, long-lasting dental fillings. Qualifying these structures is a complicated procedure; the most common method is the use of a microtensile bond strength test, for which specimens need to be formed and stabilised with adhesives in special jigs. During our research, three different cyanoacrylates were examined to find the ideal adhesive for bonding the metal and dentin and the metal and EverX short fibre composite, respectively.

Simplification of High Temperature High Pressure Equipment and Technique for Advanced Materials Processing

Combining pressure and temperature for material processing remains a challenge; if combined and applied, the potential is high for advanced material processing. In addition to advanced powder materials processing and syntheses, complicated fabrications such as joining of dissimilar materials for aerospace, pressure assisted sintering are possible with combined high pressure high temperature technique. In this study, a simplified version of high pressure high temperature equipment is designed and built. The new system eliminates/simplifies complicated and costly equipment such as hot isostatic press. The system has capacity to apply maximum gas pressure of 100 MPa and attain temperature up to 1050 °C. In addition, different processing atmospheres (inert, reducing and vacuum) are possible in the system. Special purpose jigs and fixture are designed to accommodate various processes of synthesis, sintering, joining, hot isostatic pressing and densification etc. Sintering of powder compacts and loose powder were carried out to prove the system.

Discoloration and force degradation of orthodontic elastomeric ligatures.

ABSTRACTOBJECTIVE: The aim of the present study was to evaluate color changes and force degradation of orthodontic elastomeric ligatures in different stretching patterns during a 8-weeks period. METHODS: Two elastomers with the minimum and two with the maximum color changing, and gray elastomers of two brands (American Orthodontics and Ortho Technology) were selected according to an opinion poll with clinicians and color changes after 4 weeks of intraoral use were evaluated. These elastomers were mounted on special jigs fabricated using a CAD-CAM technique, underwent different stretching patterns and the force was measured in 0, 24 hours, 2, 4 and 8 weeks. During in vivo part of the study, force levels of elastomers were measured after 4 weeks on a material testing machine. Data were analyzed with four-way ANOVA and Tukey post hoc tests.RESULTS: All the elastomers showed color changing but the degree of color stability was significantly different. The mean force degradation was higher in 1-mm stretch groups. After 8 weeks, the average residual force of elastomers was 1.45 ± 0.18 N and the maximum force decay was seen in the elastomers that exhibited the maximum initial force.CONCLUSION: There is significant relationship between the stretching pattern and the amount of residual force of elastomers. Elastomers with higher initial forces exhibited higher percentages of force loss after 8 weeks. It seems that there is a relationship between initial color and color changing of elastomers.

Long-Term Outcome of Step-Cut Ulnar Shortening Osteotomy for Ulnar Impaction Syndrome.

Extra-articular ulnar shortening osteotomy is a common procedure for the surgical treatment of ulnar impaction syndrome. Several techniques for this osteotomy have been developed to avoid the morbidity associated with a standard transverse osteotomy. However, these techniques require special instrumentation and are expensive. The purpose of this study was to evaluate the outcome of step-cut ulnar shortening osteotomy without special jigs for ulnar impaction syndrome. A retrospective study of 164 consecutive patients who underwent step-cut ulnar shortening osteotomy between 2000 and 2010 was performed. The long arm of the step-cut osteotomy was oriented in the coronal plane parallel to the long axis of the ulna. The short arms of the osteotomy were perpendicular to the long axis in the axial plane. Fixation was performed with a palmar 3.5-mm standard neutralization plate and a lag screw. The goal of the osteotomy was to reduce ulnar variance, which was assessed in all patients with pronated grip-view radiographs preoperatively and postoperatively. Preoperative ulnar variance ranged from +1 to +6 mm. All patients were followed for at least 24 months. Union of the osteotomy site was achieved at a mean of 8.2 weeks. The union rate was 98.8%. There were 2 cases of nonunion, which required additional surgery. The mean postoperative ulnar variance was +0.2 mm (range, -1 to +1.5 mm) after a mean overall ulnar shortening of 2.5 mm. All patients returned to their previous work, in a mean of 4 months. The plate was removed from 12 patients because of plate-related symptoms. No other complications were encountered. The step-cut ulnar shortening osteotomy provides ample bone-to-bone contact and simplifies control of rotation. Stable internal fixation with standard techniques allowed an early return to functional activities. Palmar placement of the plate diminishes the need for plate removal. This is a simple and less expensive technique for ulnar shortening that does not require the use of special instrumentation in patients with ulnar impaction syndrome. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Long-Term Outcome of Step-Cut Ulnar-Shortening Osteotomy for Ulnar Impaction Syndrome

Objective/Hypothesis: Extra-articular ulnar-shortening osteotomy is a common procedure for the surgical treatment of ulnar impaction syndrome. Several techniques for this osteotomy have been developed to avoid the morbidity associated with a standard transverse osteotomy. However, these techniques require special instrumentation and are expensive. The purpose of this study was to evaluate the outcome of step-cut ulnar-shortening osteotomy without special jigs for ulnar impaction syndrome. Materials and Methods: A retrospective review was performed of 164 consecutive patients who underwent step-cut ulnar-shortening osteotomy between 2000 and 2010. Eighty-eight patients were female and 76 were male with a mean age of 36.8 years. Idiopathic ulnar impaction syndrome was diagnosed in 116 patients, while a posttraumatic etiology was seen in 48 patients. The step-cut osteotomy had its long arm oriented in the coronal plane parallel to the long axis of the ulna. The short arms of the osteotomy were perpendicular to the long axis in the axial plane. Fixation was performed with a palmar 3.5 mm standard neutralization plate and a lag screw. The goal of the osteotomy was to reduce ulnar variance by shortening the ulna 2 to 3 mm and not to create neutral variance. Ulnar variance was assessed radiographically preoperatively and postoperatively with the pronated grip view in all patients. The preoperative ulnar variance ranged from +1 mm to +6 mm. Results: Mean follow-up was 62.4 months (24-86 months). Union of the osteotomy was achieved with a mean of 8.2 weeks. The union rate was 98.78%. There were 2 cases of nonunion, which required additional surgery. The mean postoperative ulnar variance was +0.2 mm (range, −1 mm to +1.5 mm) after a mean overall shortening of 2.5 mm. Modified Mayo Wrist Scores improved significantly from a mean of 47.3 (25-65) preoperatively to 88.8 (60-100) postoperatively. All patients returned to their work in a mean of 4 months. Hardware removal was performed in 12 patients (7.3%) due to plate-related symptoms. No other complications were encountered. Conclusions: The step-cut ulnar-shortening osteotomy provides ample bone-to-bone contact and simplifies control of rotation. Stable internal fixation with standard techniques allowed early return to functional activities. Palmar placement of the plate diminishes the need for plate removal caused by irritation. The step-cut ulnar-shortening osteotomy is a simple and cost-effective technique for ulnar-shortening without the use of special instrumentation in patients with ulnar impaction syndrome.

The Design and Analysis of the Hydraulic Workpiece Clamping System in the Milling Machining Process

The increasingly higher requirements of the contemporary industry contribute to the development of machining technologies, and also to the use of special jigs. The paper discusses, on the selected example, the process of designing and analyzing a special system for hydraulic clamping of simultaneously four castings to be machined on a modern CNC milling machine tool. Taking into account the possibility of a different solution to the formulated problem, two clamping system concepts are presented for making their comparison.

Mechanical Behavior of the KSTAR Central Solenoid Coil Structure During Thermal Cycles

The central solenoid (CS) coil system of the KSTAR device consists of four pairs of coils with up-down symmetry and a set of support structure. The CS coil system should endure various loads including thermal and electromagnetic load during operation. One of the most important roles of support structure is to preserve the structural stability of coil system from vertical forces by applying the pre-compression on the coil stack. The main assembly procedure of the coil stack is as follows: 1) coil subassembly and stacking, 2) structure assembly, 3) preloading process by heating shells in the support structure, and 4) measurement on the final dimension. The special jigs and heating system for the preloading were designed to apply pre-compression on the coil stack during the assembly at room temperature. Moreover, a few tens of thermocouples and strain gauges were installed for measuring temperature and thermal expansion of preloading structures. Since the final assembly of the CS coil was successfully completed with about 7.3 MN of preloading in 2006, the CS coil system has been experienced four thermal cycles from 300 K to 5 K until 2011. This paper describes the main results of applying the pre-compression on the coil stack and mechanical behaviors of preloading structures during thermal cycles.

The effect of erbium family laser on tensile bond strength of composite to dentin in comparison with conventional method

The purpose of this study was to evaluate the effect of Er:YAG and Er,Cr:YSGG laser on tensile bond strength of composite resin to dentine in comparison with bur-prepared cavities. Fifteen extracted caries-free human third molars were selected. The teeth were cut at a level below the occlusal pit and fissure plan and randomly divided into three groups. Five cavities were prepared by diamond bur, five cavities prepared by Er:YAG laser, and the other group prepared by Er,Cr:YSGG laser. Then, all the cavities were restored by composite resin. The teeth were sectioned longitudinally with Isomet and the specimens prepared in dumbbelled shape (n = 36). The samples were attached to special jigs, and the tensile bond strength of the three groups was measured by universal testing machine at a speed of 0.5 mm/min. The results of the three groups were analyzed with one-way ANOVA and Tamhane test. The means and standard deviations of tensile bond strength of bur-cut, Er:YAG laser-ablated, and Er,Cr:YSGG laser-ablated dentine were 5.04 ± 0.93, 13.37 ± 3.87, and 4.85 ± 0.93 MPa, respectively. There is little difference in tensile bond strength of composite resin in Er,Cr:YSGG lased-prepared cavities in comparison with bur-prepared cavities, but the Er:YAG laser group showed higher bond strength than the other groups.

Micropatterning on roll surface using photo-lithography processes

A direct patterning for a barrier rib using the roll-imprinting process is getting more interests in display manufacturing fields. Master roll patterning is one of the important issues in the roll-imprinting process. In this study, a novel fabrication process of micro-patterning on a roller surface by applying the photolithography process is studied. Because the roller surface was a cylindrical shape, the designed pattern was made by using a film mask. Special jigs and roll holder were designed and used for the photolithography on the roll substrate. The roll patterning results showed a feasibility of the proposed method for the photolithography on the roll’s surface.

Development of departmental standard for traceability of measured activity for I-131 therapy capsules used in nuclear medicine.

International Basic Safety Standards (International Atomic Energy Agency, IAEA) provide guidance levels for diagnostic procedures in nuclear medicine indicating the maximum usual activity for various diagnostic tests in terms of activities of injected radioactive formulations. An accuracy of ± 10% in the activities of administered radio-pharmaceuticals is being recommended, for expected outcome in diagnostic and therapeutic nuclear medicine procedures. It is recommended that the long-term stability of isotope calibrators used in nuclear medicine is to be checked periodically for their performance using a long-lived check source, such as Cs-137, of suitable activity. In view of the un-availability of such a radioactive source, we tried to develop methods to maintain traceability of these instruments, for certifying measured activities for human use. Two re-entrant chambers [(HDR 1000 and Selectron Source Dosimetry System (SSDS)] with I-125 and Ir-192 calibration factors in the Department of Radiotherapy were used to measure Iodine-131 (I-131) therapy capsules to establish traceability to Mark V isotope calibrator of the Department of Nuclear Medicine. Special nylon jigs were fabricated to keep I-131 capsule holder in position. Measured activities in all the chambers showed good agreement. The accuracy of SSDS chamber in measuring Ir-192 activities in the last 5 years was within 0.5%, validating its role as departmental standard for measuring activity. The above method is adopted because mean energies of I-131 and Ir-192 are comparable.

Review

168 Michigan Historical Review biography of George R. Maxwell will help future historians place U.S./Mormon relations in a larger context and provide federal officials‘ view of the conflict, which has been lacking heretofore. Gerrit Dirkmaat Joseph Smith Papers Project Timothy J. O‘Callaghan. Ford in the Service of America: Mass Production for the Military during the World Wars. Jefferson, N.C.: McFarland, 2009. See www.mcfarlandpub.com. Pp. 198. Appendices. Bibliography. Illustrations. Index. Notes. Paper, $35.00. Henry Ford and the firm he founded occupy a mythic place in the history of twentieth-century America. Much of the glory that accrued to both Ford and his company resulted from the pivotal role they played in making mass motorization possible, but Ford also made major contributions to the ability of the United States to wage war effectively, a story that is well told in Ford in the Service of America. Although the United States was late to enter World War I, the Ford Motor Company compiled an impressive production record during that conflict. Despite Henry Ford‘s well-publicized pacifist stance prior to America‘s entry into the war, his firm made important contributions to the war effort through the assembly of more than 2,700,000 helmets along with the manufacture of more than 30,000 vehicles, 3,950 Liberty aircraft engines, and a few prototype tanks. Ford also undertook largescale production of the Eagle submarine chaser, the first product made at the massive River Rouge Plant, although only two were delivered to the U.S. Navy prior to the war‘s end. Ford‘s efforts during World War I were just a prologue to the dazzling feats of manufacturing the company wrought during World War II. Ford was convinced that his methods of mass production were far superior to the old-fashioned, craft-based manufacturing techniques used by large numbers of military contractors. And to a large extent he was right; through the use of special jigs, fixtures, gauges, and standardized parts production, Ford cranked out massive quantities of a wide range of products. These included aircraft radial engines, wooden gliders, tents, turbochargers, ignition systems, generators, antiaircraft gun controllers, rate-of-climb indicators, and aircraft drop tanks, along with large numbers of jeeps, trucks, armored cars, and tanks. Book Reviews 169 Ford‘s most ambitious project was the manufacture of the B-24 Liberator, a four-engine bomber that was one of the most complex airplanes of its time. The chapter covering this endeavor provides some fascinating details, such as the number of parts assembled into one airplane (152,232), the number of rivets used for each airplane (313,237 of 520 different sizes), and the number of women workers at peak employment (15,412, or 39 percent of the B-24 workforce). Although there were many start-up problems, the dream of building Liberators at the rate of one per hour was eventually realized, and Ford ultimately accounted for 8,686 B-24s, nearly half the total number produced. O‘Callaghan has made good use of the Ford Archives for the information appearing in the text, appendices, and accompanying illustrations. He notes that ―the story is obviously biased towards Ford‖ due to the sources used (p. 178), but his presentation is straightforward and objective. There are however, two issues that are not completely resolved. One is the extent of Ford‘s wartime profits, which are tallied for the First World War, but not for the Second. The other has to do with the management at Ford during the latter period. The ability of the Ford Motor Company to produce a vast array of products in massive numbers seems all the more remarkable when the sharply diminished capabilities of Henry Ford and the extent of managerial infighting at the firm are taken into account. O‘Callaghan says little about Ford‘s personal involvement in his company, but he notes that the founder‘s grandson, Henry Ford II, was released from his navy service in 1943 in the hope that he would bring a more rational managerial style to the firm. However, only a few scattered references to Henry Ford II‘s activities and decisions are provided, and...

Transducers for the determination of the pressure and shear stress distribution at the stump—socket interface of trans-tibial amputees

Recent developments in prosthetic socket design have created renewed interest in monitoring the stress distribution at the socket—residual limb interface. Although a few devices for measuring pressure can be found in the literature, none are capable of measuring reliably in areas of high curvature, such as the important area at the patellar tendon bar. Furthermore, few devices can record shear stress, thought to be critical in causing tissue damage. In order to address these issues two new transducers have been designed and evaluated. One design allows the simultaneous recording of the normal and shear stresses at various points of the socket walls, while the other is capable of measuring the three components of the force applied on the patellar tendon. The latter design incorporates a feature that permits displacement of the patellar tendon bar, in order to study the effect of various amounts of indentation of the tendon on the stress distribution around the residual limb. Both transducers were calibrated using dead weights and special jigs to ensure accurate loading conditions. Under laboratory bench conditions the normal—shear force transducer showed: 2.03 per cent full scale output (FSO) hysteresis error for shear stress direction, 1.65 per cent FSO for normal direction; 99.56 per cent FSO overall accuracy for shear direction, and within 99.64 per cent FSO for normal direction; and for the patellar tendon transducer 1.53 per cent FSO hysteresis error for shear direction, 1.85 per cent FSO for shear stress direction; 99.65 per cent FSO overall accuracy for shear direction, and 99.58 per cent FSO for normal direction. During an amputee walking trial the transducers showed 92 per cent to 97 per cent repeatability. The two new transducers were used in conjunction with two other types of transducers, previously designed at the University of Strathclyde, in a series of tests on ten trans-tibial amputees. Sample results for walking activities and a summary of maximum stresses recorded are presented.

Evaluation of a Tibial Torsiometer Applicable to Clinical Practice

This study evaluated a new tibial torsiometer that is universally applicable to all limb sizes and requires no special training, jigs, or radiographic equipment. To compare the reliability of measurements obtained with the torsiometer, 160 tibias were evaluated with both the torsiometer and computed tomography. Results for both methods were identical in 51 tibias, within 1 degrees in 66 tibias, and within 2 degrees in 43 tibias. The difference between the two methods was not significantly different. No significant difference was found among testers. This device should prove to be useful for the quantitation of tibial torsion.

Optimal Structure Design Methodology for Compound Multiaxis Machine Tools - I - Analysis of Requirements and Specifications -

The functionality of compound multiaxis machine tools is becoming increasingly versatile as NC lathes evolve. A single compound multiaxis machine tool functions as a 2-axis NC lathe and as a 5 axis machining center. The compound multiaxis machine tool executes machining such as inclined surface and gear cutting, conventionally executed by dedicated machines with special jigs and fixtures. A survey has shown that most machining executed by conventional compound multiaxis machine tools consists of basic drilling and milling on the orthogonal plane, indicating that compound multiaxis machine tools specifications should be designed to meet these requirements. To improve competitiveness and return investment over conventional NC lathes and machining centers, productivity required for a compound multiaxis machine tool is derived based on the machining time of typical parts on conventional machines. Here, we address systematic analysis and methodology to determine compound multiaxis machine tool specifications from the viewpoints of quality and cost.

Exposure setup to study potential adverse effects at GSM 1800 and UMTS frequencies on the auditory systems of rats

To investigate possible biological effects of exposure to electromagnetic (EM) fields at the frequencies of global system for mobile communication (GSM) 1800 system and universal mobile telecommunication system (UMTS) on the auditory system of rats, an exposure setup for in vivo experiments is presented. The study was carried out in the framework of two European research projects. The target of the investigation was the cochlea. A dosimetric study was performed, both numerically and through direct measurements, to assess the interaction of the radiated fields and the dose distribution in the biological target. For the local exposure of rats, a loop antenna operating at the frequency bands of interest was designed, realised and characterised through numerical and experimental dosimetric procedures. Moreover, an exposure apparatus was set up, consisting of three arrays of four loop antennas, placed on three levels, thus allowing simultaneous exposure of 12 rats to give statistical power to the experiments. To isolate the exposure arrays, the setup was assembled by a wooden rack with EM field absorbing panels, inserted among the levels and at the four sides of the rack. Isolation was verified by direct measurements. Two exposure arrays were simultaneously supplied, whereas the third one was used for sham exposure. Blind exposure was achieved through a black box, hiding physical connections to the microwave power supply. During exposure sessions, rats were restrained in special plastic jigs for repeatable positioning, thus assuring the fixed level of dose in the target.

Two column lesions in the thoracolumbar junction: anterior, posterior or combined approach? A comparative biomechanical in vitro investigation

There are various surgical techniques for the treatment of spinal fractures in the thoracolumbar region. Several implants have been developed for anterior or posterior instrumentation. Optimal treatment of unstable thoracolumbar osseous and ligamentous injuries remains controversial. To compare the stabilizing effects of an antero-lateral, thoracoscopically implantable plate system (macsTL, Aesculap, Germany) with the stability provided by a fixateur interne (SOCON, Aesculap, Germany), this in vitro investigation examined six human bisegmental (T12-L2) spinal units. Specimens were tested intact, and with simulation of osseous lesions in the anterior and ligamentous lesions in the posterior column (combined A/B-fracture). While loaded in the main anatomical planes such as flexion/extension, left and right lateral bending and left and right axial rotation with a bending moment of 7.5 Nm in a special testing jigs, motion analysis was performed. Quantitative interpretation of the stabilizing effect was achieved using a contactless three-dimensional motion analysis system. Each specimen was tested in four different scenarios: the first step measured movements of intact spinal segments. For the second step, specimens underwent simulation of combined A/B-fracture provided with bisegmental (T12/L2) antero-lateral fixation and bone strut graft from the iliac crest. For the third step, segments were additionally stabilized by the fixateur interne. The last measurement (fourth step) was performed after removing the anterior instrumentation. Range of motion (ROM) values were compared and statistically evaluated. Compared to the intact specimens the anterior instrumentation of the combined lesion, simulated A/B-fracture, leads to a stabilizing effect in flexion/extension and lateral bending. In contrast to these findings the torsional instability increased for the upper segment and bisegmentally. A maximum rigidity, beyond intact values, was registered for each anatomical plane with the combined instrumentation: antero-lateral and fixateur interne. After removing the anterior screw plate system maximum movements, in all segments for flexion/extension and lateral bending, bisegmentally and for the upper segment in axial rotation, were less than ROM values measured with the anterior system only. With respect to these findings a combined ventro-dorsal stabilization procedure should be considered for ligamentous disruptions of the posterior column in combination with A-fractures in the thoracolumbar junction.

Influence of strain on the high-frequency magnetic properties of FeCoBSi thin films

Magnetostrictive amorphous FeCoBSi thin films for sensor applications have been investigated with regard to their magnetic properties dependent on strain. With special test jigs, allowing measurements in a vibrating sample magnetometer, Kerr-Effect microscope and high frequency permeameter, the magnetic dc and high frequency properties as a function of applied strain were investigated and correlated to the domain behavior. Under the condition that the applied strain stabilizes the magnetic easy axis in an orientation perpendicular to the high frequency magnetic field direction these magnetostrictive thin films can be used as cores of microinductors monitoring the strain via inductance changes. With FeCoBSi films a material quality factor of 10 and a high gauge factor (Δμ/μ 0 /Δe) of 2400 is obtained at 250 MHz.