Special Drill Research Articles

A Modified Technique for Anterior Cruciate Ligament (ACL) Surgery Using a New Drill Guide for Isometric Positioning of the ACL

In reconstructing the anterior cruciate ligament (ACL) it is important to place the inner ends of the drill channels correctly, to get the ACL into an isometric position. Anatomic studies demonstrate the value of a modified surgical technique using a special drill guide for standardized positioning of the anterior cruciate substitute. The drill guide consists of a metal frame with one adjustable and one fixed guide tube. Drilling is done from the anteromedial aspect of the tibia, upwards, through the joint space and the femur in a straight line, both channels being drilled in a single procedure. The precision of guided drilling was superior to that of free-hand drilling in positioning the ligament in the correct anatomic place.

Drilling with Twist Drills of Different Cross Section Profiles

Summary First a short analysis and description is given about the profile geometry of special twist drill. Different groups of profiles are defined. The influence of the cross section profile to the torsional stiffness was determined and related to the drilling process. Torque and thrust were measured under variation of speed, feed, depth and point geometry. Testing the different dynamic behaviour of the twist drills is included.

On the Drilling of Metallic and Nonmetallic Sheets

The drilling conditions to obtain a good shape and fine accuracy in dimension of drilled holes in metallic sheets of mild steel (S35C), brass (6/4 brass) and duralumin (2017) as well as in nonmetallic sheets of bakelite, vinyl and acryl with conventional standard twist drills or a fishtail point special drill were examined. The results obtained are as follows:In the case of drilling metallic sheets with conventional standard drills of different point angles, the drillled hole shows more enlarged hole diameter, more distorted shape and larger pile-up at the hole-inlet as the drill point angle becomes wider.In the case of drilling nonmetallic sheets, the influence of the point angle is little and a circular hole is easily obtainable. And if the point angle is obtuse, the burr at the hole-outlet is little even in metallic sheets, but the cracks tend to appear at the hole-outlet in nonmetallic sheets.In the case of drilling with a special drill, the enlargement of hole diameter is smaller compared with the case with a standard drill and a circular hole is obtainable. But, in drilling nonmetallic sheets, large cracks tend to appear at the hole-outlet and the burr at the hole-outlet is smaller compared with the case of standard drill.For the drilling of bakelite, it has been proved that a good drilled holes is obtainable by drilling after placing bakelite on top of aluminium sheet. The drilled hole shows no cracks, little enlargement of hole diameter and little pile-up or burr.

The Teaching of a Foreign Language in a Modular System of Instruction

A further difficulty is the heavy demand made on the instructor throughout the semester. At least thirty hours per week in teaching, preparations, and examination marking are required of him. Invaluable would be an assistant, who could correct quizzes, prepare supplementary class material, and conduct special afternoon drill sessions for students having difficulty with any phase of the daily work.

The Teaching of a Foreign Language in a Modular System of Instruction

A further difficulty is the heavy demand made on the instructor throughout the semester. At least thirty hours per week in teaching, preparations, and examination marking are required of him. Invaluable would be an assistant, who could correct quizzes, prepare supplementary class material, and conduct special afternoon drill sessions for students having difficulty with any phase of the daily work.

Use Of Cylindrical Specimens In Evaluation Of SomeMechanical Properties Of In-situ Wood Members

Method of testing compressive strength of wood using small diameter cores was developed. Special core drill was used to cut 5mm-diameter cores from wood members. Cores were drilled in the direction perpendicular to the fibers and were tested in concave jaws which applied the force in the direction along the fibers. Correlation between strength of cores and the strength of ASTM specimens in compression and tension was established.

Drilling of aluminum alloy plates with special type point drill

Drilling of aluminum alloy plates with special type point drill

Drilling of aluminum 2S plate with special type point drill

The effects of shape and dimensions of drill on the figure and accuracy in dimensions of drilled hole, drilling resistance, etc. are discussed for drilling of aluminum alloy plates with a fishtail point drill.The results obtained were as follows.Some heaps at the hole inlet and burrs at the hole outlet were produced in drilling of soft plates such as 2S and 3S, but they were not so large in height as those produced by the conventional drills. However, the worked hole surface obtained by the point drill was superior to that by the conventional drills. The drilling machinability with respect to drilling resistance, enlargement of hole diameter, heaps and burrs, etc. of hard plates such as G4 and 52S by the fishtail point drill was superior to that of soft plates such as 2S and 3S, and the machinability of 14S, 61S, etc. was arranged in medium order. Of course, there is no trouble in drilling of hard plates such as G4 and 52S with the fishtail point drill, but the conventional drills can be used for this purpose. Then, it is concluded that the fishtail point drill is not so favorable for these hard materials.

A new intraoral parallelometer

A new parallelometer and a technique for its use have been described. This precision instrument is rigid, and has proved to be very accurate. No play in the instrument is allowed, and parts that wear out are easily replaced. It is used when preparing teeth for pinledges, inlays; for making grooves and ☐es for 3/4 crowns; and to check the alignment of multiple preparations. The instrument requires the use of special drills and stones. Paramax-drills are used for making the postholes, slightly conical fissure-burs, and diamond stones with the Paramax grib, and when preparing teeth for three-quarter crowns and full veneer crowns.

Tight Hole and Closed Chamber Testing - A New Technique for Formation Evaluation

Abstract The closed chamber and tight hole methods of well testing described in this paper are designed to overcome some special drill stem test problems existingat the surface. The primary purpose for conducting this type of drill stem testis to utilize a system that offers maximum secrecy and/or maximum control of fluid recovery; therefore, maximum safety. The problem of secrecy commonly occurs in Canada, and the tight hole technique was developed so that only authorized personnel would be able to determine the type of recovery and the pressure involved. The closed chamber method has application wherever a high degree of controlof the recovery is desired, such as in townsite and night-time testing, neither of which can be accomplished safely by the conventional drill stem test method.This method also permits a high degree of safety when testing high-pressure gassands. Experience with closed chamber testing has indicated that the fluid recovery data may be applicable for empirical analysis to determine reservoir fluid properties provided that certain problems are recognized. Static reservoir pressure can be determined by employing the initial shut-in-flow-period method described in the text of the paper. However, problems are encountered when attempting to utilize the pressure buildup curveto determine transmissibility and permeability with the degree of accuracy obtainable from a conventional drill stem test. Examples of pressure curves from tight hole and closed chamber systems are included and discussed. Introduction Tight hole testing was developed to provide maximum secrecy of drill stem test results in Canada. In order to maximize secrecy, it was necessary to provide a testing system that would not allow fluid recovery to be exposed to unauthorized personnel on or off the rig floor. The tight hole assembly consists of a closed chamber which allows the standsof drill pipe forming the chamber to be separated, drained and set aside in the derrick without revealing any recovery, even in the tool joints, to unauthorized personnel. Secrecy requires the elimination of surface indications during the test and the bringing of the recovery to the surface in such a manner that it will not flow freely from tool joints onto the floor or into the derrick. The recovery has to be removed from the chamber with maximum controlin order to provide secrecy. The conditions required for secrecy result in an increase in the safety of testing.

Stored energy in the graphite stack of the IR reactor

Storage of Wigner energy and the nature of stored energy release were investigated in the graphite stacks of the IR reactor. The investigations were carried out on graphite bricks removed from the reactor stack as the latter was being dismantled. Other samples were cut out from the reactor stack with the aid of a special drill cutter during the two years after the stack was dismantled, when an additional integral flux of thermal neutrons 2.2 ·1021 neutrons/cm2 developed. The samples were so chosen that the pattern of stored-energy distribution throughout the stack might be obtained. Stored Wigner energy was determined by the technique of two successive heatings of the samples to temperatures of 600–650 ° C in vacuum calorimeters, making possible an energy release during the anneal. The total quantity of stored energy was determined by combustion of the graphite in a standard solid fuel testing calorimeter.

Instruments for Use with Flexible Steel Wire in Bone Surgery

A wire tightener has been developed which tightens and then twists the ends of wire loops in a manner which is reproducible from loop to loop, and which does not place excessive strain on the basic twist where loops are liable to be weakened so that they subsequently break. Fifteen years of surgical experience have proved the dependability of this instrument and the value of its unique features. It provides strong and reliable fixation of bone fragments in a diversity of surgical procedures in which wire loops have the virtues of introducing a minimum of foreign material and of holding bone fragments in constant contact. The tightener is designed for use with 18-gauge and 20-gauge surgical stainless- steel wire, which sizes have been found most suitable for internal fixation of the major bones of the upper and lower extremities. Two devices have also been developed which expand the field of usefulness of the tightener. The wire-washer set provides strong longitudinal fixation through a single drill hole in bone. The C clamp, with removable drill guide and special drill, aids in reducing certain fractures about major joints, and in holding the fragments securely during appropriate internal fixation. These two devices are of limited application but of great usefulness in specific situations.

Dermabrasion technique with diamond fraises.

After considerable experiment with the various methods of dermabrasion—steel burs, the stainless steel wire brushes, the hochtouriges Schleifen of Schreus, and our own method with dental diamond and ruby fraises—we found none of these methods efficient. A firm which specializes in diamond instruments made a number of special fraises and drills for us. As regards the type of drill, a cylindrical fraise with edges rounded off and a somewhat globular surface like a barrel proved to be the most suitable. As regards the diamond particles and the setting of the surface, it soon appeared that the dental fraises were too fine for our purpose, both as regards the size of the particles and the closeness of the setting of the surface. The coarser the diamond particles and the more widely they are separated, up to a certain point, the sharper the fraises become and the less quickly the surface

時計用特細密錐の切削の研究(第3報)

時計用特細密錐の切削の研究(第3報)

NOTES ON AKLAVIK RELOCATION PROJECT, 1954

ABSTRACTDuring the summer of 1954 rather more scientific field studies than usual were sponsored by the Canadian Government in the comparatively little known Mackenzie River Delta. One of these studies was the site survey for Akhrvik.Following the Government's proposal to relocate Aklavik, a small but growing settlement built on low, unstable ground, in the delta, a team of scientists spent the period from April to August 1954, investigating possible sites for a new town. Much of the material presented in this paper was obtained by the author while serving as a member of the Aklavik Relocation Survey Team. Personnel on the survey team consisted of five engineers and three specialists in geography and geology representing the following federal departments: Department of Northern Affairs and National Resources, Division of Building Research of the National Research Council, Department of Mines and Technical Surveys, Department of Public Works, Department of Transport, Department of National Health and Welfare. The use of this material has been possible by the kind permission of Colonel F.G.H. Cunningham, Director of the Northern Administration and Lands Branch. A number of social, economic, and physical factors, which defined the site requirements, limited the search to places where a navigable channel approached high ground along the delta flanks. The best place available was a location 33 air miles east of Aklavik. In November 1954, a decision was made to relocate Aklavik at this place. Site development work will be done this year with the new construction and moving operations extending over a four year period.The survey was carried out from a series of base camps under canvas, at or near the potential sites. The early start, two months before break‐up, permitted the examination of each location during winter, break‐up, and summer conditions. Aerial reconnaissance was made by helicopter, and as the seasons progressed, tractor, dog team, outboard craft, scow and barge, provided surface transportation. Soils data were obtained from frozen cores secured with a special drill developed by National Research Council engineers for use in permafrost, and from test pits. Rough surveys were made to indicate the availability of materials for roads and aggregate, the area and drainage of the surface, and the availability of a site for an airstrip. Hydrographic and related surveys were made to establish the navigability of the access channel, the location for the wharf, and the most suitable provision for a domestic water supply.Several additional studies, primarily of scientific interest, were carried out by members of the survey as opportunity was presented in the course of the primary work. It is gratifying to note that Mr. Roger Brown and Mr. Keith Fraser will present papers today recording work of this nature, carried out while participating in the Aklavik survey. A sharing of ideas in the form of the work mentioned above, and in contacts with other scientific parties in our area, was most beneficial in maintaining an interest and awareness in our work, through a long field season.

Recent advances in fertilizer placement. I. Fertilizer placement for swedes and turnips in Scotland

AbstractDuring 1947‐52 over 40 field experiments were carried out to compare broadcast and band applications of sulphate of ammonia, superphosphate, muriate of potash, 40% potash salts and two granular NPK fertilizers. Placement positions at distances up to 3 in. to the side of the row and up to 3.5 in. below the soil surface were examined by using a special drill machine developed by the National Institute of Agricultural Engineering. Placing superphosphate directly below the seed at a depth of about 3.3.5 in. from the soil surface has consistently given higher yields than placing it in other positions or broadcasting. The results show that there is no advantage in placing sulphate of ammonia, and that placing it directly below the seed may be harmful to early growth. There is no benefit or disadvantage from placing muriate of potash (60% of K2O), but with 40% potash salts broadcasting is likely to be better than placing below the seed. With NPK fertilizer mixtures there does not appear to be any benefit from placing, and this seems to be due to the positive effect from superphosphate being counterbalanced by the negative effect from a mixture of nitrogen and potash.

Placement of fertilizers for row crops

In experiments on peas, beans, carrots, kale, beetroot and spinach appropriate dressings of fertilizers placed in one band 3 in. below the soil surface and 2 in. to the side of the seed did not damage germination. Peas and beans are likely to be injured when even small dressings of soluble fertilizers are drilled in contact with or below the seed.In sixteen experiments on peas and nineteen experiments on beans in 1949–51 broadcast fertilizer gave small increases in yield of beans and peas in dry years and larger increases in wet years. In about one-quarter of all the experiments fertilizer broadcast early and either ploughed or cultivated deeply into the soils gave significantly higher yields than late dressings worked into the seed-beds. In roughly one-third of all the experiments on each crop there were significant increases in yield from placing as compared with broadcasting fertilizer. The average extra yields produced by placing fertilizer were 1·8 cwt. per acre of threshed peas, 9·3 cwt. per acre of green peas, 1·0 cwt. per acre of winter beans and 1·3 cwt. per acre of spring beans. For spring-sown crops extra yields from placement were greater than the increases from broadcasting fertilizer. There was little advantage from splitting the fertilizer dressing, broadcasting half and placing the remainder beside the seed.In most experiments on peas and beans, yields given by a single dressing of placed fertilizer were equal to, or greater than, the yields given by double dressings of broadcast fertilizer. When placed in the correct position quite small quantities of fertilizer are sufficient for maximum yields of such crops. The use of suitable drills should be profitable to farmers growing appreciable acreages of peas, beans and rapidly maturing horticultural crops. Where special placement drills are not available, fertilizers for peas and beans should be broadcast before cultivating to prepare the seed-bed and, when possible, the dressings should be ploughed-in. There was no advantage from placing fertilizer at the side of the seed for carrots, kale or beet. Placed fertilizer gave a higher yield of spinach than broadcast fertilizer.Placing fertilizer at the side and below the level of the seed is likely to give better yields than broadcast fertilizer for crops having short growing seasons or poorly developed roots and when broadcast nutrients are immobilized in the surface soil by drought.

Methods of applying fertilizers for herbage crops

Phosphate-potash fertilizer was drilled in bands 20 in. apart and 3 in. below the soil surface and compared with similar dressings broadcast on the surface for established crops of sainfoin. On unmanured plots yields were not reduced by cutting grooves for the fertilizer bands. Broadcasting fertilizer on the surface produced consistently more sainfoin hay than dressings placed in bands. In similar experiments on permanent grass broadcast fertilizer also gave consistently more hay than bands of fertilizer placed 10 in.apart. Intheabsence of fertilizer small decreases in yields of grass were caused by cutting grooves. The advantages of an equal supply of nutrients to all the plants in an established sward, obtained by broadcasting fertilizers, outweighs any disadvantage from confining the application to the soil surface.Two experiments on lucerne in 1950–51 compared broadcast dressings of phosphate-potash fertilizer harrowed into the seed-bed with the same quantities of fertilizer placed in one band 2 in. to the side of the seed. Side-band placement did not give better early growth than broadcasting. Broadcast fertilizer gave higher yields of hay than placed fertilizer at one centre in the first year. There were no significant differences at either centre between yields of hay given by broadcast and placed fertilizer in the second year. When the dressings were divided, half being applied at sowing-time and the remainder in the spring of the following year, slightly lower yields were obtained than from dressings applied wholly at sowing.A further experiment on lucerne was laid down in spring 1952. Superphosphate, muriate of potash and a mixture of the two fertilizers were compared both when broadcast and ploughed in and when broadcast on the seed-bed. All the dressings of broadcast fertilizer were tested in the presence and absence of a ‘starter-dose’ of superphosphate drilled directly beneath the seed. The ‘starter-dose’ gave much better early growth and higher yields of lucerne than any of the dressings of broadcast phosphate and potash. Broadcast fertilizer ploughed in tended to give higher yields at the first cutting than seedbed dressings. At the second cutting there was little difference between yields given by ploughed-in dressings and dressings broadcast on the seed-bed.There is no case for introducing special equipment to place fertilizer in bands below the surface of established swards. For establishing lucerne and other ley crops, where fertilizers may be applied at or before sowing, there are no advantages from using special drills to place the full dressing of fertilizer at a safe distance to the side of the seed. Where combine-drills are used for sowing herbage crops they should be modified to place a small quantity of superphosphate directly beneath the seed and the remainder of the fertilizer should be broadcast before sowing.

The Iowa Language Program

IN THE FALL OF 1944 at the University of Iowa a new Liberal Arts program was introduced which also brought about an essential change in language instruction and in foreign language requirements. Under the old plan elementary (first and second) year language classes had been taught three times a week, and a total of twelve semester hours was regarded as the fulfillment of the language requirement. The new plan requires the passing of a foreign language achievement test (spoken or written) by all students who expect to receive a B.A. degree. The test is independent from any course work though ordinarily a student with one year of language training (8 sem. hrs.) under the new plan, or two years (12 sem. hrs.) under the old plan, and satisfactory class work is regarded well prepared for it. Elementary courses in foreign languages at present are offered on a one-year basis with three hours of lecture and two hours of drill per week, with a total of 8 sem. hrs. (4 plus 4 sem. hrs.) for the academic year. The reduction of the teaching time from two years to one makes it imperative to concentrate very definitely on one goal only, reading or speaking. Whereas in our department of Romance languages the reading method has been well established for years, in German up to 1944 a mixed course had been offered with the stress on oral work in the first year and on reading in the second. Now two types of elementary courses are taught in the modern language departments, reading and speaking, the choice between the two being left to the student (who selects his courses with the help of his personal advisor). During 1944-45 the ratio of enrollment in the spoken and reading classes was about 1:3 in German, 2:1 in Spanish and 1:1 in French respectively. In either course the main classes (about 20 students in speaking, 25 in reading) are taught by experienced instructors, whereas the drill group (15 in reading, 10 in speaking) are conducted by younger staff members or by special drill masters who for the speaking groups must be native speakers. Main (lecture) classes are scheduled on Mondays, Wednesdays and Fridays; drill hours essentially on Tuesdays and Thursdays (Two German reading drill groups had

Colombian Students at the University of Pennsylvania

N THE summer of 1941 the Institute of International Education, cooperating with the Office of the Coordinator of Inter-American Affairs in Washington, requested the University of Pennsylvania to receive a group of some thirty visiting students from the Republic of Colombia, and to prepare for them a program of studies and activities extending from December 4, 1941, to January 26, 1942.x This the University of Pennsylvania consented to do. The preparation of a suitable program was a serious responsibility. It was recognized from the first that the objectives were to be not only academic, but also political, in the sense that the plan was intended to contribute its part to the success of the Good Neighbor Policy, and, through that success, to the building of a better Greater America. At no time did we think in terms of courses for which academic credit could be given.2 We sought, rather, to provide intellectual stimulus, to broaden horizons, to make known American techniques, to provide a view of what we North Americans plan to accomplish as we move forward into the future; and we hoped also that our guests could obtain, in addition to such a view of what we do, a conception of what we are--of our artistic, musical, and social life, and, with a very special emphasis, our home life. In our effort to achieve the first of these purposes, we decided against organizing special courses for the visitors, since experience had shown that a large portion of a foreign student's first six weeks is required to overcome the language difficulty. Our first step was to organize brush-up work in English, consisting both of our Spanish I course in reverse, and also of special drill in overcoming difficulties of pronunciation, conducted by an expert in English phonetics. Parallel with this, we arranged a tabulation of all our regular courses in which these students might, in our judgment, be interested. To these courses, and to any others that they might choose, their matriculation cards gave them admission, as well as to our libraries,