The present work deals with developing a fuzzy back propagation neural network scheme for prediction of drill wear. Drill wear is an important issue in the manufacturing industries, which not only affects the surface roughness of the hole but also influences the drill life. Therefore, replacement of drill at an appropriate time is of significant importance. Flank wear in a drill which depends u...

This paper presents a new thermal model for bone drilling with applications to orthopaedic surgery. The new model combines a unique heat-balance equation for the system of the drill bit and the chip stream, an ordinary heat diffusion equation for the bone, and heat generation at the drill tip, arising from the cutting process and friction. Modeling of the drill bit-chip stream system assumes an...

The analysis of drill cutting angles is important for the design of high-performance drill geometry. The cutting angles along the cutting edge of a drill are determined by the combination of its flute and flank surfaces. This paper examines the analysis of both flute and flank surface models and the evaluation of drill cutting angles. A new mathematical model for an arbitrary drill flute face i...

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for structure joining. Delamination is one of the serious concerns during drilling. Practical experience shows that an eccentric twist drill or an eccentric candle stick drill can degrade the quality of the fiber reinforced material. Comprehensive delamination models for th...

Designing a high-performance twist drill is difficult due to the complex relationship between drill geometry and numerous and conflicting design goals. Earlier approaches of computer-aided twist drill design are limited to only few design aspects. This article presents a new holistic method of using computing power for twist drill design and optimization. A complete drill geometry model is used...

Weight on the bit is accomplished by running in the hole, between the bit and the drill pipe, several lengths of extremely heavy thick-walled pipe, called “drill collars”. Drill pipe may weigh up to 30 kg/m. Drill collars, of larger diameter than drill pipe and of constant diameter throughout, can weigh up to IS0 kg/m. The full hanging weight of the whole assembly in the blocks in the derrick (...

this study evaluated direct drilling planters used for wheat cultivation in khorasan-e razavi province. a randomized complete block design with three replications was used. the treatments were direct drilling of wheat plants into wheat residue using the following direct planters: (1) sfoggia (13-25), (2) baldan (spd3000), (3) tondar (spd 2500), (4) semeato (shm 11/13). the parameters measured w...

PURPOSE To determine whether a wire-guided single drill protocol could be utilized without causing an increase in bone temperature beyond those seen with the traditional techniques of sequential drilling with and without a drill guide. MATERIALS AND METHODS A bovine femoral bone model was used with thermocouples and infrared temperature measurements to record thermal increase of the bone and ...

PURPOSE It is difficult for emergency physicians to plan and execute a disaster medical response drill while conducting their daily work activities. Readily available drill preparation manuals are therefore essential, alongside assessment methods to ensure quality. Here, we propose email text analysis as a manual assessment method, and investigate its validity. METHODS The preparation status ...

The drill makes use of four rods to obtain the full length drill string which allows to reach a penetration depth of 2 meters. The first rod is the real drill tool with sample collection capability; the other 3 rods are extension rods. The real drill tool is installed at the mandrel during launch, the other three rods are stored in a dedicated rod magazine together with a back up drill tool. Al...