نتایج جستجو برای: ceramic petrography

تعداد نتایج: 24512  

2009
A. Zhang Y. Guan W. Hsu Y. Liu A. D. Patchen L. A. Taylor

Introduction: Equilibrated lithic clasts in unequilibrated chondrites probably represent thermal metamorphism in the early solar system before or during accretion of chondritic parent bodies. Lithic clasts with equilibrated features are rare in unequilibrated chondrites and their origins are not well-understood [1]. Recently, we observed an unusual lithic clast with thermal-metamorphosed featur...

2003
R. H. Jones J. T. Wasson T. Larson Z. D. Sharp

Petrography: The interior of the stone consists of relatively small (mean grain size 1.6 mm), angular olivine grains (~73 vol%) in an iron metal matrix (Fig. 1). Ferric oxides are abundant. Samples easily fragment because of the weathering and numerous, probably preterrestrial, fractures. Olivine contains numerous small (typically 50 μm diameter) inclusions, visible in the SEM, that consist of ...

2001
P. E. Stutzman

Concrete petrography is used to assess damaged concrete in order to determine the probable mechanism of damage. However, using traditional petrographic analyses, it is often difficult to say what mechanisms caused the crack damage, since many deterioration mechanisms produce cracks. This article describes a hybrid imaging-finite element modelling technique that can be used to help determine the...

2003
Z. R. Dai J. P. Bradley D. E. Brownlee D. J. Joswiak

Introduction: At least some meteoritic nano-diamonds are likely of presolar origin because of their association with anomalous Xe-HL and Te isotopic components indicative of a supernova (SN) origin [1,2]. But the abundance of Xe is such that only ~1 in 10 6 nano-diamonds contains a Xe atom, and the bulk 13 C/ 12 C composition of nano-diamond acid residues is chondritic (solar) [3]. Therefore, i...

Journal: :African Archaeological Review 2023

Abstract The site of Jebel Moya, situated in the center southern Gezira Plain southcentral Sudan, has an occupational sequence spanning at least five millennia until around 2000 years ago. Renewed excavation is shedding new light on its chronology and socioeconomic history, including activities such as burial, savanna herding, domesticated sorghum cultivation practices dating to mid-third mille...

2013
Jae-Hwi Nho Jong-Seok Park Ui-Seoub Song Woo-Jong Kim You-Sung Suh

Revision rates of total hip arthroplasty have decreased after introducing total hip arthroplasty (THA) using ceramic component, since ceramic components could reduce components wear and osteolysis. The fracture of a ceramic component is a rare but potentially serious event. Thus, ceramic on polyethylene articulation is gradually spotlighted to reduce ceramic component fracture. There are a few ...

2011
Girish Nazirkar Suresh Meshram

Background: Metal ceramic restorations are highly popular and are used for most of the crown and bridge restorations made today. Aims: To evaluate the translucency and fracture strength of two all-ceramic and traditional metal ceramic crowns. Materials and Methods: Thirty crowns of similar size and shape were constructed to fit a standard brass die. Ten crowns were manufactured from each of the...

2016
Shanchuan Zhang Penghua Ma Guanchao Wang Qiang Sun Lili Tian Lili Ma Baohua Xu

To systematically review the randomized controlled trials (RCTs) and compare the survival rates and complications of all-ceramic fixed dental prostheses (FDPs) with those of metal-ceramic FDPs. Eligible studies were retrieved in relevant electronic databases from their inception to June 8th, 2016. Then, quality of the included studies was assessed using Cochrane Collaboration’s tool. Heterogene...

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