Proper Tension Research Articles

Autonomy vs. Accountability in Higher Education: The Quest for a Proper Tension

(1981). Autonomy vs. Accountability in Higher Education: The Quest for a Proper Tension. The Review of Education: Vol. 7, No. 2, pp. 159-166.

Stability of the upper lumbar spine following progressive disruptions and the application of individual internal and external fixation devices.

Five fresh human cadavera were tested to determine range-of-motion measurements at the interspace of the first and second lumbar vertebrae after progressive disruption of the joint followed by internal and external stabilization. The disruption progressed from posterior to anterior, leaving the anterior longitudinal ligament and anterior part of the annulus fibrosus intact. Flexion-extension range of motion was most sensitive to progressive disruptions and was significant following disruption of the facets. The Taylor-Knight brace was effective for limiting lateral motion, fair for limiting flexion-extension, and not effective for rotation. The three-point hyperextension brace was fairly effective for flexion-extension only. The body cast was effective in limiting all motions. Wire loops partially cut through the spinous processes in all cases with extreme flexion. Harrington distraction rods were effective in limiting motion if under proper tension, but they dislodged in three of the five specimens. Data from this study show that flexion of the second lumbar vertebra on the first of 20 degrees or a lateral bend of 10 degrees seen on a routine roentgenogram without vertebral fracture indicates that all posterior ligaments and at least part of the annulus fibrosus must be disrupted. Because internal fixation failed on occasion, we strongly urge the use of external fixation and careful mobilization of the patient to prevent flexion and rotation if internal stabilization is used for disruptions of the upper lumbar spine. The body cast was the most effective in limiting motion of the external fixation devices tested.

Harnessing and exporting Antarctic icebergs

The harnessing of icebergs might be accomplished in a number of ways. The harness should be able to apply thrust to the iceberg throughout its life for acquisition in the Antarctic, for transfer to the using destination, and for mooring while being converted for fresh water and cooling. The harness must be able to handle the varying thrusts in both magnitude and direction and accommodate the shrinking iceberg as it is melted and finally completely converted (Ref. 1). The harnessing method that seems best able to satisfy all requirements is to surround each iceberg in the horizontal plane below the center of mass with a cable network or sling. Proprietary techniques can be used to maintain the harness in its proper location, under proper tension, and with appropriate distribution of stresses on the ice near “corners” of high stress. Connecting points for towing and mooring lines can be made available at each “corner” (Ref. 2). The energy required to obtain fresh water from alternative supplies is an important consideration. Previous studies (Ref. 3) indicate that for large scale transfers from the Antarctic to California in about a year-long trip, the work done is equivalent to lifting the ice about 10 meters. Most of this energy is used to overcome skin friction. The Coriolis forces offer great resistance at the extreme southern latitudes, but their average effect over the total transfer for the range of possible net Coriolis fractions from 1 to 0 is about plus or minus 20 percent about a Coriolis fraction of 0.5. Conventional large propellers are less than 5 percent efficient in providing thrust at speeds less than one knot so that the energy consumption for the iceberg transfer would be equivalent to that of an efficient water pump lift of about 200 meters. However, there are promising proprietary techniques for engaging more than a hundred times the area of water for thrust than is feasible with conventional propellers which should improve the propulsion efficiency to as high as 25 percent at speeds of one knot. Environmental factors such as currents and winds do not appear to influence greatly the energy or time required to transfer icebergs if sufficient thrust is used to make the transfer to the Northern Hemisphere in about a year or less time (Ref. 3).

The Use of a Tendon Transfer for the Treatment of a Traumatic Sciatic Nerve Paralysis in the Dog

A case of a traumatic sciatic nerve paralysis was successfully treated with the transfer of the long digital extensor tendon of origin to the vastus lateralis muscle after a portion of the latter had been separated from its insertion on the patella. A second procedure was necessary to shorten the distal tendon of the long digital extensor muscle to create the proper tension needed to fully extend the digits. Within 11 weeks after surgery the dog was successfully returned to training and field trial competition. Viability of the transfer was further demonstrated by electrical stimulation of the vastus lateralis one year later.

Indicis tendon transfer. technique and results (author's transl)

We examined 38 patients out of 41 with indicis tendon transfer, performed at the Department for Hand Surgery of the University of Munich during the past eight years; the patients had suffered a subcutaneous rupture or an open traumatic separaton of the extensor pollicis longus tendon. In five cases the function fo the operated had was found deteriorated by other causes. Of the remaining 33 patients 26 showed an excellent function and five patients a good function of the operated thumb. Deficient functional results were discovered with two patients. Almost in all cases extension of the index finger was found reduced in force; none of the patients, however become aware of it. In performing the tendon anastomosis care must be taken to apply proper tensions to the tendons joined.

Sternal wire closure by an instrumental method

Effective median sternotomy closure requires approximation of the sternum under appropriate tension in an expeditious manner. An instrument has been developed to provide tightening of applied sternal wires, allowing proper tension to be established. After tightening, the twisted wire is automatically trimmed by the instrument. The ease and reproducibility of this wire closure technic has allowed the method to be performed on a routine basis.

傾斜坑道におけるスチールテープの適正張力について

The largest personal error will be a distance one in a mine traversing survey.The almost solution of this problem will be obtained, if the reading of the steel tape can show the exact distance when the steel tape is stretched by the proper tension. The optimum tension of the steel tape changes by the inclination and the length of the steel tape.In level road it has been already solved but in the case of slope the proper method has been not established up to the present.From this point of view, the author has made the simple and effective calculating formular.

Recurrent urinary stress incontinence treated by the fascia lata sling procedure

The results and complications in treating 23 patients with 25 fascia lata sling procedures are reported. The cure rate was 88 per cent in these 23 women, who had previously undergone a total of 53 unsuccessful procedures for the treatment of stress incontinence. Uncontrollable detrusor overactivity reduced the over-all cure rate to 76 per cent. The importance of careful preoperative assessment is stressed and the value of bladder and urethral pressure studies in preoperative assessment, in achieving proper sling tension, and in postoperative assessment is indicated. Emphasis is placed on the fact that delayed voiding and problematic residual urine following are caused by hypotonic or incoordinate detrusor muscle action. A routine for managing these two problems is outlined.

The Surgical Technique of Total Hip Arthroplasty, Modified from Charnley, as Done at the Mayo Clinic

SUMMARY Using the technique described for total hip arthroplasty, we have been able to visualize the hip clearly and restore the biomechanics properly after placement of both the acetabular and femoral components. Whereas in surgery of the uncomplicated, simple osteoarthritic hip, many of the details can be omitted and a simpler exposure can be used, advantages have been gained from the clear vision afforded. The central displacement of the acetabulum stressed by Charnley, the return of the trochanter under proper physiologic tension, and the neutral or slight valgus position of the femoral component are integral parts of the surgical technique.

Operative cystic duct cholangiography.

To the Editor.— Operative cystic duct cholangiography, introduced by Mirizzi in 1937, continues to be a valuable tool and has its advocates in many quarters. Its use remains as a vexing technical pathway unless one maintains facility in performing the maneuver. Consistent good quality records are difficult to obtain and each operator has his own peculiar method of accomplishing this intraoperative roentgenogram. The intracystic duct cannula, a metal tube as originally described by Mirizzi, 1 has numerous modifications. The latest, an 18-gauge plastic catheter tipped with an expanded head, still requires that a ligature be placed about the cystic duct with just the proper tension to prevent leakage of contrast material but not occlude the tube. The Orr cystic duct clamp concept has eliminated many of our technical problems (Dittmar and Penn Corp, Philadelphia). We have modified a right angle clamp as seen in the Figure. A 2-mm groove is

Stainless Steel Plate as Spring Material

It is the aim of this paper to report on experimental study on highly effective method of annealing stainless steel plate to give it proper tension as spring material. Hereunder are summarized the results of our study.(1) The stainless steel plate is to be annealed in the following method. Its tension is to be first reduced to 30% by cold rolling, and then the plate is to be annealed at 400-650°C of temperature in non-oxidative atmosphere, under tension not exceeding 20% of tensile strength.(2) The springs made of stainless steel processed in the above mentioned method have about twice as much strength in fatigue strength and spring limit as copper alloyed springs, and the steel thus annealed, being productive of high resilient mechanism, is fit for production of all varieties of springs.(3) The passivation of stainless steel treated in the above mentioned procedure is to be made in solution of 30% HNO 3+1% HF at about 30°C temperature.

Repair of the Anterior Cruciate Ligament in Dogs

1. No transected anterior cruciate ligament healed unless the ligament ends were held in complete apposition by suture. 2. Excessive tension on the suture line of the primarily repaired anterior cruciate ligament resulted in necrosis of the ligament and failure of the repair. 3. The divided anterior cruciate ligament in thirty consecutive dogs healed when treated by surgical repair apposing the severed ends under proper tension. 4. Prompt absorption and shortening of the ligament followed section of the anterior cruciate ligament without repair to the extent that apposition was impossible as early as two weeks after section. 5. Sectioned and repaired anterior cruciate ligaments showed microscopic evidence of complete fibrous healing by ten weeks, but there was still minimum residual fibroblastic activity at this time. 6. Tensile strength of the healed repaired ligament remained substantially less than that of normal ligaments at ten weeks. 7. When the anterior cruciate ligament was replaced with a graft composed of the iliotibial tract, a fibroblastic response occurred throughout the entire graft. It may be this response that converts the graft into a ligamentous structure. 8. The grafts were shown to survive as ligamentous structure up to four years after operation. 9. In our series the reconstructed ligament did not seem to provide stability comparable with that provided by the healed primarily repaired ligament, but there were insufficient animals in this series to reach valid conclusions in this regard.

逆張力附加引抜法の研究（第3報）炭素鋼線について（その2）

Following 2nd report, we carried out the wire drawing of patented 0.6% carbon steel wire with back tension and obtained following results. (1) For the smaller reduction, the tensile strength is almost unchangeable in the case of proper back tension, but its yield strength and the twisting property increase slightly and the elastic limit considerably. (2) For the higher reduction the tensile strength of the wire drawn with proper back tension decreases, while the yield strength, the elastic limit and the twisting property increase. (3) When the wire is drawn with the same total reduction, the smaller the number of passes, the higher the tensile strength, the yield strength and elastic limit of the wire drawn with backtension. (4) In the ordinary process, the diameter of wire is larger than the diameter of die at its exit; this difference becomes smaller with the increase of the back tension. This is proved by the elastic expansion of die, and the plastic contraction and elastic expansion of drawn wire. (5) Using a die having large die angle and no bearing part, the diameter of drawn wire becomes smaller than the exit aparture of the die, as if the outflow of liquid, but using a die having small die angle and a bearing part, the diameter of drawn wire becomes larger. (6) At the entrance of a die, the wire already reduces its diameter in front of the contact point with the die wall. (7) When the same amount of wire is drawn, the amount of wear of the die having small die angle and long bearing part is larger than that of the die having large die angle and short bearing part, but the enlargement of die diameter of the former is smaller than that of the latter.

A Method for Measuring Radon Seeds

The method and the instrument about to be described have been in constant use during a period of several months and have proved to be such a rapid, safe and reliable means of measuring radon seeds that it has seemed worth while to describe them in some detail. The instrument used is a simple string electroscope, shown in Fig. 1. AB is very fine, platinum-coated quartz fiber (Diam. 2 to 5 microns) suspended at A with a fine U-shaped piece of quartz, which acts as an insulator as well as a spring to provide the proper tensions in the quartz fiber. A screw arrangement at C is provided for raising and lowering A. B is connected at the mid point of a 100,000 ohm wire wound resistance whose ends are connected to two plates E and E'. E is insulated from the case G with good bakelite and is also mounted on a screw so that it may be moved toward or away from E'. This provides a method for electrically balancing the electroscope. The resistance is also mounted on bakelite. The ion collecting grid H in the ionization chamber I, and E', are carefully insulated with amber. A contacting key J, having silver contacts, makes or breaks electrical connection with E' by releasing or pressing a key some distance from the instrument. K is a 90-volt Radio B battery and supplies the potential for both the electroscope and ionization chamber.

Railway Inclined Catenary Standardized Design

A description is given of a new method of overhead contact design, the ``ideal inclined catenary.'' This is based on an originally discovered tension and weight relation formula. A proof of the formula is given and other characteristics of the design are mathematically analyzed. A number of railroads now using inclined catenary is listed and data on the weights and tensions of their overhead constructions are given for comparison purposes with the ``ideal.'' The necessity of making a definite selection of a proper contact wire tension in any inclined catenary design is indicated and that this, together with the use of the design formula, leads to standardization of overhead systems is pointed out.