Hole drilling operations are common in fibre reinforced plastics FRP’s to facilitate fastener assembly to other parts in more complex structures. As these materials are non-homogeneous, drilling causes some damages, like delamination, for example. Delamination can be reduced by a careful selection of drilling parameters, drill material and drill bit geometry. In this work two types of laminates...

Deburring of cross-drilled holes by secondary erosion of an abrasive jet was carried out and the parameters were identified. The detailed studies carried out on the parameters indicate that the parameter stand-off distance, burr root-to-stopper distance, abrasive grit size and mixing ratio significantly affect the deburring process. A burr model for 90° cross-drilled holes is also presented in ...

The paper presents a novel method for monitoring and estimating the depth of a laser-drilled hole using machine vision. Through on-line image acquisition and analysis in laser machining processes, we could simultaneously obtain correlations between the machining processes and analyzed images. Based on the machine vision method, the depths of laser-machined holes could be estimated in real time....

Examination of piston cores and, particularly, sediments collected by the Deep Sea Drilling Project has shown that authigenic dolomite occurs in a wide range of sedimentary associations. While the trace to a small percentage of dolomite often encountered in pelagic carbonate sequences may be a result of authigenesis under "normal" deep-sea conditions, the few studies to date seem to indicate th...

Snow density estimates below the surface, used with airplane-acquired ice-penetrating radar measurements, give a site-specific history of snow water accumulation. Because it is infeasible to drill cores across all Antarctica measure and because critical understand how climatic changes are affecting world's largest freshwater reservoir, we develop methods that enable estimation uncertainty in re...

Fifty-four coal clast samples in the siliciclastic rocks (e.g., sandstone and conglomerate) were collected from cores of two-deep research wells (K20H K20K) drilled at Kozlu coalfield Zonguldak Basin, for first time, they evaluated using mineralogy by XRD SEM-EDX random vitrinite reflectance (%Rr) measurements order to find out their origin timing. Petrographic observations on polish surfaces s...

Glaciers are among the world's best recorders of, and first responders to, natural and anthropogenic climate change and provide a time perspective for current climatic and environmental variations. Over the last 50 years such records have been recovered from the polar regions as well as low-latitude, high-elevation ice fields. Analyses of these ice cores and of the glaciers from which they have...

Bone drilling is one of the most common operations used to repair fractured parts of bones. During a bone drilling process, microcracks are generated on the inner surface of the drilled holes that can detrimentally affect osteosynthesis and healing. This study focuses on the investigation of microcracks and pullout strength of cortical-bone screws in drilled holes. It compares conventional surg...

The Xining Basin in Qinghai Province, China, is rich mid–low temperature geothermal resources, but the reinjection of water has not yet started. In this paper, physical properties rocks sampled from newly drilled well DR2018 were analyzed, and a series core flooding experiments was conducted to assess formation blockage risk during reinjection. experimental results show that reservoir low poros...

CONTEXT Solid pseudopapillary tumors of the pancreas are rare and have recently been shown to harbor mutations of the beta-catenin gene with resultant nuclear localization of beta-catenin protein to the nucleus. Moreover, there is a close relationship between beta-catenin and E-cadherin. OBJECTIVE To explore the protein expression of E-cadherin in a series of solid pseudopapillary tumors of t...