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 ...

Redox-inactive metal ions can modulate the reactivity of redox-active metal ions in a variety of biological and chemical oxidations. Many synthetic models have been developed to help address the elusive roles of these redox-inactive metal ions. Using a non-heme manganese(II) complex as the model, the influence of redox-inactive metal ions as a Lewis acid on its catalytic efficiency in oxygen at...

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 IODP-ICDP Expedition 364 drilling recovered a 829 m core from Hole M0077A, sampling ˜600 of near continuous crystalline basement within the peak ring Chicxulub impact structure. bulk consists pervasively deformed, fractured, and shocked granite. Detailed geochemical investigations 41 granitoid samples, that is, major trace element contents, Sr–Nd isotopic ratios are presented here, providin...

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...

BACKGROUND Various techniques for quadriceps tendon repair have been described with biomechanical studies suggesting greater failure threshold with longitudinally placed drill holes. 1 The current gold standard for repair uses 3–4 sutures 2 passed through parallel longitudinal transpatel-lar bone tunnels. We describe a simple and reproducible technique Figure 1 Acufex ® Director™ Drill Guide po...