Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 186 for “"apatite"”.
-
Structural characterisation of apatite-like materials
Hydroxyapatite (HA) is an important material for biomedical applications and has found application as bone substitute and implants coating due to the high similarity to the inorganic material of bone and tooth. Usually the HA lattice in living organism is substituted by different cations in order …
-
Innovative Apatite/Bioactive Glass-based materials for biomedical applications
… calcium phosphates (in particular hydroxyapatite) and bioactive glasses, recently gained much attention due to their characteristics as promising materials for the treatment of non-self-healing bone defects. Indeed, they display biocompatibility, good bioactivity and non-toxicity. Despite …
-
Apatite-polymer composites for the controlled delivery of bone morphogenetic proteins
Current treatment of bone defects due to trauma, cancer, or degenerative spine diseases involves the implantation of a bone graft. Autografts, which are harvested from the patient's own body, are associated with problems of limited availability and surgical morbidity. The use of allografts obtained …
-
Using Lunar Apatite to Assess the Volatile Inventory of the Lunar Interior
… melt inclusions, glass beads, and the mineral apatite have challenged the previously held notion that the Moon is depleted in volatiles. As the most widespread volatile-bearing phase, apatite has been the focus of many studies aiming to constrain the volatile inventory of the lunar interior. …
-
Composite materials made of chitosan and nanosized apatite : preparation and physicochemical characterization
… containing chitosan and nanosized hydroxyapatite were investigated. A new preparation approach based on a co-precipitation method has been developed. In its earlier stage of formation, the composite occurs as hydrogel as suspended in aqueous alkaline solution. In order to get solid …
-
On apatite fission-track analysis and heat transfer processes in the upper crust
… confined track-length measurements from detrital apatites recovered from Ocean Drilling Program (ODP) Leg 116 Site 717 and 718 cores of distal Bengal Fan sediments provide information on both the thermal history of sediments recovered at these two sites and the cooling rates of apatite source …
-
Production of phosphorus alloys through thermal reactions and electrochemical reduction of molten apatite
A process for extracting phosphorus from fluorapatite through high temperature electrochemical means. Theoretical modelling and calculations show that P-alloys can be manufactured directly from decomposed molten fluorapatite. Nickel-phosphide is chosen as an examplary alloy both for its incredible …
-
Timing of erosional episodes in the Marble Canyon and Vermilion Cliffs region from apatite (U-Th)/He thermochronology
The history of incision of the Marble Canyon segment of Grand Canyon, and the rate of retreat of the Vermilion Cliffs portion of the Grand Staircase, are examined using a synthesis of new and published low-temperature thermochronology datasets. I test models for a 50-70 Ma Marble Canyon and …
-
Interpreting Early Triassic (Smithian) sea-level change and climate using sequence stratigraphy and oxygen isotopes of conodont apatite
… for oxygen isotopic analyses of conodont apatite from the two field locations (in Utah) in a sequence stratigraphic framework to better understand the Smithian paleoclimate. Due to an up to ~1.5 ° disparity of values between the two locations, additional conodont elements were analyzed …
-
Neoproterozoic to Holocene tectonothermal evolution of the southern Cantabrian Mountains NW Iberia, revealed by apatite fission-track thermochronology
… for more often observed substitutions to the apatite chemical formula [Ca_10(PO_4)_6(F,Cl,OH)_2], to predict correlation between AFT grain-ages and their respective D_par values. Graphs constructed for AFT central-age versus latitude and elevation yield negative slopes, indicating a complex …
-
Cenozoic exhumation history of the northern Richardson Mountains: Results from apatite and zircon (U-Th-Sm)/He analysis
… cooling during late Eocene–early Oligocene time. Apatite (U-Th-Sm)/He (AHe) data were collected from 19 Proterozoic–Paleocene rocks across a 115 km transect. Eighty-eight single-grain AHe dates range from 300 ± 5 Ma to 16 ± 4 Ma but most dates (65%) range 56–24 Ma. AHe dates are generally younger …
-
Long-term exhumation of landscapes along the Pacific-North American plate boundary as inferred from apatite (U-Th)/He and ArcGIS analyses
… area. In the northern San Gabriel Mountains, apatite (U-Th)/He ages are >10 Ma along narrow crystalline ridges topped by low-slope erosional surfaces located within ~5 km of the San Andreas fault zone. In the Chugach-Kenai Mountains, the youngest apatite (U-Th)/He ages (~5 Ma) are an order of …
-
Integrating apatite (U-Th)/He and fission track dating for a comprehensive thermochronological analysis: refining the uplift history of the Teton Range
… is a result of intense zoning, primarily in apatite from Precambrian layered gneisses. Nonetheless, both the AHe and AFT ages consistently indicate slight differential uplift of the Tetons between the Late Oligocene and Middle Miocene. HeFTy models indicate that doming of the …
-
Study on the performance enhancement of biomedical implants: in vitro test under UV irradiation of titanium anodised in mixed electrolyte
… the bioactivity of TiO2 surface; that is the apatite formation ability. The apatite formation of the TiO2 coating was precipitated by using simulated body fluid (SBF) in the dark and under the ultraviolet (UV) irradiation to mimic the reactions that may occur with the human bone-like cells …
-
Stable carbon isotopes in deep time : the diets of fossil fauna and hominids
… using the mineral phase of calcified tissues (apatite) as alternative sample material to collagen. The results reported here provide empirical evidence for the validity of the technique. Investigation of the isotopic relationships between diet, collagen and apatite, using a large sample of …
-
Reconstructing the diets of southern African farmers: comparing stable isotopes across body tissues
… are presented for each individual (δ¹³Cbone apatite, δ¹³Ctooth enamel, δ¹³Ccollagen, δ¹⁵Ncollagen). Dietary reconstructions using both typical 'fractionation factor' methods and recent bi- and multi-variate models are presented and compared. For this population, which consumed primarily C4 …
-
In vitro bioactivities of anodised titanium in mixtrue of B-Glycerophosphate and calcium acetate for biomedical application
… methods particularly to accelerate the bone-like apatite formation on the anodised titanium in a shorted time: (1) UV irradiation during in vitro testing and (2) adding additives in electrolyte. After soaked and irradiated with UV in simulated body fluid (SBF) for 7 days, highly crystallised …
-
Quantifying South African uplift : using apatite fission track thermochronology and offshore sediment volumes to test the balance between denudation (onshore) and deposition (offshore) since Gondwana break-up
Includes bibliographical references (leaves 201-217).
Page 1 of 10