نتایج جستجو برای: drill

تعداد نتایج: 5712  

2015

Advantages  Technology allows for improved diamond deposition process, which results in stronger adhesion.  Improved adhesion of the film produces lower stresses to thereby increase the drill lifetime.  When compared to untreated drill bit, our drill bit was able to drill over 100 holes, whereas the untreated only drilled 40 holes before breaking. o Increased durability over 50% Diamond film...

2012
F. Abdul Majeed H. Karki Y. Abdel Magid M. Karkoub

This paper analyses the non linear properties exhibited by a drill string system under various un balanced mass conditions. The drill string is affected by continuous friction in the form of drill bit and well bore hole interactions. This paper proves the origin of limit cycling and increase of non linearity with increase in speed of the drilling in the presence of friction. The spectrum of the...

2001
Jianhua Yu

Drill-bit seismic data can provide valuable information about reflector characteristics and prediction ahead of the drill bit. In this paper, I apply the interferometric migration method, which both includes crosscorrelogram and autocorrelogram migration, to Union Pacific Resources Corporation (UPRC) drill-bit data. Here, the data are recorded on the earth’s free surface while a tri-cone drill-...

2014
P. D. Jenkins

Management intervention to avoid inbreeding in captive breeding programs is essential to maintain maximum genetic diversity. Vasectomy was enlisted in drill monkeys (Mandrillus leucophaeus) to achieve this purpose without altering the social dynamics of the groups. All the vasectomies were carried out at the Drill Rehabilitation and Breeding Centre, Cross River State, Nigeria. Vasectomy in dril...

Journal: :تحقیقات مهندسی کشاورزی 0
اورنگ تاکی استادیار پژوهش بخش تحقیقات فنی و مهندسی مرکز تحقیقات کشاورزی و منابع طبیعی اصفهان اردشیر اسدی عضو هیئت علمی بخش تحقیقات فنی و مهندسی مرکز تحقیقات کشاورزی و منابع طبیعی اصفهان

no tillage systems can reduce operating costs, enhance soil organic matter, ameliorate soil structure and prevent environmental damage caused by stubble burning. however, the lack of an appropriate direct drill for the hardened soil of arid areas reduces adequate soil-seed contact and, thus, the system has shown contradictory results in past tests. developing a direct drill to place the seed an...

2017
Yosuke Akiba Kaori Eguchi Nami Akiba Katsumi Uoshima

PURPOSE Zirconia is a good candidate material in the dental field. In this study, we evaluated biological responses against a zirconia drill using a bone cavity healing model. MATERIALS AND METHODS Zirconia drills, stainless steel drills, and the drilled bone surface were observed by scanning electron microscopy (SEM), before and after cavity preparation. For the bone cavity healing model, th...

2013
Rosario Domingo Manuel García Alberto Sánchez Rosa Gómez

This paper presents a study of hole quality and energy consumption in the process of drilling a thermoplastic polymeric material, polyether-ether-ketone, reinforced with 30% glass fibers (PEEK-GF30). PEEK-GF30's capacity to be machined has focused on turning operations. Studies of drilling involving thermoplastic polymeric materials have considered materials with other types of matrices, or rei...

Journal: :Clinical oral implants research 2015
David Schneider Florian Schober Philipp Grohmann Christoph H F Hammerle Ronald E Jung

OBJECTIVE The aim of this in-vitro study was to compare the tolerance of surgical instruments in surgical guides produced by 3-D printing, without metal sleeves to a surgical guide with conventional metal sleeves from two different manufacturers. MATERIALS AND METHODS Lateral movements of drill tips caused by tolerance between the sleeve and drill key and between the drill key and the drill w...

2017
Somil Jaiswal A. K. Chaudhuri S. N. Ghosh S. Ghosh S. K. Saha Pooja Jaiswal

Aim: To compare two most common operative procedures used in patients with chronic subdural hematomas Twist drill craniostomy and Burr Hole Craniostomy. Material and Methods: The study was a prospective randomized controlled trial on patients with chronic subdural hematomas. Results: Both procedures are comparable with respect to outcome but surgical duration is statistically higher in Burr Hol...

2013

Traditional methods for the disposal of Oil-Based Mud (OBM) drill cuttings have included pit burial or leaving the untreated cuttings scattered in-situ. Increasingly stringent regulations and increased environmental awareness have required new and improved disposal techniques. Scomi Equipment Inc, with over twenty one years Drilling Waste Management experience, has developed a system to remedia...

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