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Peter B Kelemen - One of the best experts on this subject based on the ideXlab platform.
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geochemistry and magmatic history of eclogites and ultramafic rocks from the chinese continental scientific Drill Hole subduction and ultrahigh pressure metamorphism of lower crustal cumulates
Chemical Geology, 2008Co-Authors: Keqing Zong, Peter B KelemenAbstract:Abstract Three distinct groups of eclogites (low-Mg–Ti eclogites, high-Ti eclogites and Mg-rich eclogites) and ultramafic rocks from the depth interval of 100–680 m of the Chinese Continental Scientific Drill Hole were studied. The low Mg#s (= 100 ⁎ molar Mg/(Mg + Fe)) (81–84%) and low Ni (1150–1220 ppm) and high Fe 2 O 3 total (13–15 wt.%) contents of ultramafic rocks suggest a cumulate origin. Mg-rich eclogites show middle and heavy REE enrichments, which could not be produced by metamorphic growth of garnet. Instead, if the rocks formed from a light REE enriched magma, there may be an igneous precursor for some garnets in their protolith. Alternatively, perhaps they formed from a light REE depleted magma without garnet. The high-Ti eclogites are characterized by unusually high Fe 2 O 3 total contents (up to 24.5 wt.%) and decoupling of high TiO 2 from low Nb and Ta contents. These features cannot be produced by concentration of rutile during UHP metamorphism (even for samples with TiO 2 > 4 wt.%) of high-Ti basalts, but could be attributed to crystal fractionation of titanomagnetite (for those with TiO 2 2 > ∼ 4 wt.%). Thus, we suggest that protoliths of the high-Ti eclogites were titanomagnetite/ilmenite-rich gabbroic cumulates. As a wHole, the low-Mg–Ti eclogites are geochemically complementary to the high-Ti eclogites, Mg-rich eclogites and ultramafic rocks, and could be metamorphic products of gabbroic/dioritic cumulates formed by high degree crystal fractionation. All these observations suggest that parental materials of the ultramafic rock-eclogite assemblage could represent a complete sequence of fractional crystallization of tHoleiitic or picritic magmas at intermediate to high pressure, which were later carried to ultrahigh-pressure conditions during a continental collision event.
Richard C. Allen - One of the best experts on this subject based on the ideXlab platform.
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The subperiosteal, Drill Hole, midface lift
Orbit, 2016Co-Authors: C. Blake Perry, Richard C. AllenAbstract:This article describes a surgical technique using Drill Holes through the inferior orbital rim and fixation with permanent sutures as a functional subperiosteal midface lift and compares it to other standard midface elevation techniques. This was a retrospective, comparative, non-randomized study. Charts of all patients undergoing midface elevation between 2009 and 2013 were reviewed. Pre- and post-operative photos were graded on a scale 0 to 3 with 0 representing normal lower lid position and lid/cheek junction and 3 representing the most severe malposition. Twenty-seven patients (35 sides) underwent midface lift. Twelve sides had the subperiosteal Drill Hole midface lift; 9 preperiosteal with Vicryl suture fixation to periosteum; 14 subperiosteal with Endotine midface B device. All groups had similar demographics and indications for surgery. Average follow-up time was greater than 4 months in all groups. No significant complications were seen in any of the patients. The average post-operative grade of the Drill Hole group was 0.65 compared to 0.75 of the preperiosteal Vicryl group and 0.7 of the Endotine group. The Drill Hole group had the most severe pre-operative malposition. Overall, the Drill Hole group demonstrated the largest improvement score. The subperiosteal Drill Hole technique proved to be an effective method for functional midface elevation. This technique achieves adequate and durable vertical elevation without relying on the strength of the periosteum or use of a commercial device.
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The subperiosteal, Drill Hole, midface lift
Orbit, 2016Co-Authors: C. Blake Perry, Richard C. AllenAbstract:ABSTRACTThis article describes a surgical technique using Drill Holes through the inferior orbital rim and fixation with permanent sutures as a functional subperiosteal midface lift and compares it to other standard midface elevation techniques. This was a retrospective, comparative, non-randomized study. Charts of all patients undergoing midface elevation between 2009 and 2013 were reviewed. Pre- and post-operative photos were graded on a scale 0 to 3 with 0 representing normal lower lid position and lid/cheek junction and 3 representing the most severe malposition. Twenty-seven patients (35 sides) underwent midface lift. Twelve sides had the subperiosteal Drill Hole midface lift; 9 preperiosteal with Vicryl suture fixation to periosteum; 14 subperiosteal with Endotine midface B device. All groups had similar demographics and indications for surgery. Average follow-up time was greater than 4 months in all groups. No significant complications were seen in any of the patients. The average post-operative gr...
Don O. Kikkawa - One of the best experts on this subject based on the ideXlab platform.
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Orbitomalar suspension with combined single Drill Hole canthoplasty.
Ophthalmic Plastic and Reconstructive Surgery, 2013Co-Authors: Oh, Bobby S. Korn, Don O. KikkawaAbstract:Whether resulting from a surgical complication or involutional change, lower eyelid retraction and canthal dystopia can lead to lagophthalmos and frank ectropion. The authors present their experience with a single Drill Hole fixation for both the lateral canthus and suborbicularis oculi fat for severe canthal dystopia and lower eyelid retraction. In this retrospective, consecutive study, the medical records of 13 patients who underwent single Drill Hole canthoplasty and suborbicularis oculi fat suspension were reviewed. A 4-0 nonabsorbable polypropylene suture was used to secure the canthal tendon, passed through a single lateral orbital rim Drill Hole from inside out. The suborbicularis oculi fat was then suspended in the same manner. Outcome measurements included linear marginal reflex distance 2, lagophthalmos, and subjective assessment of the results by the patient. Preoperatively, the average linear marginal reflex distance 2 was 7.3 ± 1.0 mm, the average lagophthalmos was 3.5 ± 0.8 mm, and the average horizontal palpebral fissure width was 25.7 ± 1.3 mm. Postoperatively, average linear marginal reflex distance 2 was 5.3 ± 0.7 mm (p < 0.05), average lagophthalmos was 0.3 ± 0.4 mm (p < 0.05), and average horizontal palpebral fissure width was 30.2 ± 0.7 mm (p < 0.05). All patients noted symptomatic relief and were satisfied with the appearance of their eyelids at 6 months of follow up. Single Drill Hole canthoplasty with suborbicularis oculi fat suspension is a viable alternative to previously described procedures. By using a single bony Drill Hole, rigid fixation is achieved with avoidance of multiple fixation points.
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Orbitomalar suspension with combined single Drill Hole canthoplasty.
Ophthalmic Plastic and Reconstructive Surgery, 2013Co-Authors: Bobby S. Korn, Don O. KikkawaAbstract:PURPOSE Whether resulting from a surgical complication or involutional change, lower eyelid retraction and canthal dystopia can lead to lagophthalmos and frank ectropion. The authors present their experience with a single Drill Hole fixation for both the lateral canthus and suborbicularis oculi fat for severe canthal dystopia and lower eyelid retraction. METHODS In this retrospective, consecutive study, the medical records of 13 patients who underwent single Drill Hole canthoplasty and suborbicularis oculi fat suspension were reviewed. A 4-0 nonabsorbable polypropylene suture was used to secure the canthal tendon, passed through a single lateral orbital rim Drill Hole from inside out. The suborbicularis oculi fat was then suspended in the same manner. Outcome measurements included linear marginal reflex distance 2, lagophthalmos, and subjective assessment of the results by the patient. RESULTS Preoperatively, the average linear marginal reflex distance 2 was 7.3 ± 1.0 mm, the average lagophthalmos was 3.5 ± 0.8 mm, and the average horizontal palpebral fissure width was 25.7 ± 1.3 mm. Postoperatively, average linear marginal reflex distance 2 was 5.3 ± 0.7 mm (p < 0.05), average lagophthalmos was 0.3 ± 0.4 mm (p < 0.05), and average horizontal palpebral fissure width was 30.2 ± 0.7 mm (p < 0.05). All patients noted symptomatic relief and were satisfied with the appearance of their eyelids at 6 months of follow up. CONCLUSIONS Single Drill Hole canthoplasty with suborbicularis oculi fat suspension is a viable alternative to previously described procedures. By using a single bony Drill Hole, rigid fixation is achieved with avoidance of multiple fixation points.
Keqing Zong - One of the best experts on this subject based on the ideXlab platform.
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geochemistry and magmatic history of eclogites and ultramafic rocks from the chinese continental scientific Drill Hole subduction and ultrahigh pressure metamorphism of lower crustal cumulates
Chemical Geology, 2008Co-Authors: Keqing Zong, Peter B KelemenAbstract:Abstract Three distinct groups of eclogites (low-Mg–Ti eclogites, high-Ti eclogites and Mg-rich eclogites) and ultramafic rocks from the depth interval of 100–680 m of the Chinese Continental Scientific Drill Hole were studied. The low Mg#s (= 100 ⁎ molar Mg/(Mg + Fe)) (81–84%) and low Ni (1150–1220 ppm) and high Fe 2 O 3 total (13–15 wt.%) contents of ultramafic rocks suggest a cumulate origin. Mg-rich eclogites show middle and heavy REE enrichments, which could not be produced by metamorphic growth of garnet. Instead, if the rocks formed from a light REE enriched magma, there may be an igneous precursor for some garnets in their protolith. Alternatively, perhaps they formed from a light REE depleted magma without garnet. The high-Ti eclogites are characterized by unusually high Fe 2 O 3 total contents (up to 24.5 wt.%) and decoupling of high TiO 2 from low Nb and Ta contents. These features cannot be produced by concentration of rutile during UHP metamorphism (even for samples with TiO 2 > 4 wt.%) of high-Ti basalts, but could be attributed to crystal fractionation of titanomagnetite (for those with TiO 2 2 > ∼ 4 wt.%). Thus, we suggest that protoliths of the high-Ti eclogites were titanomagnetite/ilmenite-rich gabbroic cumulates. As a wHole, the low-Mg–Ti eclogites are geochemically complementary to the high-Ti eclogites, Mg-rich eclogites and ultramafic rocks, and could be metamorphic products of gabbroic/dioritic cumulates formed by high degree crystal fractionation. All these observations suggest that parental materials of the ultramafic rock-eclogite assemblage could represent a complete sequence of fractional crystallization of tHoleiitic or picritic magmas at intermediate to high pressure, which were later carried to ultrahigh-pressure conditions during a continental collision event.
Xian-lai Wang - One of the best experts on this subject based on the ideXlab platform.
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Wear mechanism and serious wear position of casing pipe in vertical backfill Drill-Hole
Transactions of Nonferrous Metals Society of China, 2011Co-Authors: Qin-li Zhang, Jing-jing Zheng, Xin-min Wang, Xian-lai WangAbstract:Abstract Vertical backfill Drill-Hole is usually a key project in an underground mine with backfill method and can be easily damaged by impact of backfill slurry. Observation of the damaged vertical backfill Drill-Holes in Jinchuan Nonferrous Metal Corporation (JNMC), Gansu Province, China, given by a digital Drill-Hole video camera, indicated that there usually exist serious wear zones in casing pipe in vertical backfill Drill-Hole (CVBH). It was suggested that serious wear position of CVBH should be located at an interface between air and solid-liquid mixture within CVBH. Backfill slurry falls freely and impacts the wall of CVBH near the interface with great momentum and energy coming from high speed free fall of backfill slurry. The depth of serious wear position of CVBH, i.e., free fall height of backfill slurry in CVBH, can be estimated by the height of vertical backfill Drill-Hole, the length of horizontal pipeline, the density of slurry and the hydraulic gradient of pipeline system. A case study indicated that the estimation equation of serious damage depth of CVBH was of enough accuracy and was helpful for daily maintenance and management of vertical backfill Drill-Hole.
