Fractionation of nitrogen isotopes in a synthetic diamond of mixed crystal habit

Nature ◽  
1988 ◽  
Vol 331 (6157) ◽  
pp. 604-607 ◽  
Author(s):  
S. R. Boyd ◽  
C. T. Pillinger ◽  
H. J. Milledge ◽  
M. J. Mendelssohn ◽  
M. Seal
Keyword(s):  
Mixed Crystal ◽  
Nitrogen Isotopes ◽  
Synthetic Diamond ◽  
Crystal Habit

Correlation between the Nitrogen Impurity Content and the Crystal Habit of Synthetic Diamond

Nature ◽  
1968 ◽  
Vol 218 (5148) ◽  
pp. 1246-1247 ◽  
Author(s):  
B. R. ANGEL ◽  
M. J. A. SMITH ◽  
J. J. CHARETTE
Keyword(s):  
Synthetic Diamond ◽  
Impurity Content ◽  
Crystal Habit ◽  
Nitrogen Impurity

Reflection electron microscopy of as-grown diamond surfaces

1993 ◽  
Vol 51 ◽  
pp. 1006-1007
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton
Keyword(s):  
Electron Microscopy ◽  
Synthetic Diamond ◽  
High Energy ◽  
Dark Field ◽  
Reverse Direction ◽  
Diamond Surfaces ◽  
Grain Sizes ◽  
Synthetic Diamonds ◽  
De Beers ◽  
Reflection Electron Microscopy

It has been found that the abrasion of diamond-on-diamond depends on the crystal orientation. For a {100} face, the friction coefficient for sliding along <011> is much higher than that along <001>. For a {111} face, the abrasion along <11> is different from that in the reverse direction <>. To interpret these effects, a microcleavage mechanism was proposed in which the {100} and {111} surfaces were assumed to be composed of square-based pyramids and trigonal protrusions, respectively. Reflection electron microscopy (REM) has been applied to image the microstructures of these diamond surfaces.{111} surfaces of synthetic diamond:The synthetic diamonds used in this study were obtained from the De Beers Company. They are in the as-grown condition with grain sizes of 0.5-1 mm without chemical treatment or mechanical polishing. By selecting a strong reflected beam in the reflection high-energy electron diffraction (RHEED) pattern, the dark-field REM image of the surface is formed (Fig. 1).

A Thick Overgrowth of CVD Synthetic Diamond on a Natural Diamond

2018 ◽  
Vol 36 (2) ◽  
pp. 134-141
Author(s):  
Shi Tang ◽  
Jun Su ◽  
Taijin Lu ◽  
Yongwang Ma ◽  
Jie Ke ◽  
...  
Keyword(s):  
Synthetic Diamond ◽  
Natural Diamond

Identification of a CVD Synthetic Diamond with a 'Tree Ring' Growth Pattern

2015 ◽  
Vol 34 (8) ◽  
pp. 702-710
Author(s):  
Yan Lan ◽  
Rong Liang ◽  
Taijin Lu ◽  
Yong Zhu ◽  
Tianyang Zhang ◽  
...  
Keyword(s):  
Tree Ring ◽  
Growth Pattern ◽  
Synthetic Diamond

Effect of diamond burnishing parameters on the state of the processed surface layer of billets made of high-strength "30ХГСН2А-ВД" steel

2020 ◽  
pp. 82-86
Author(s):  
A.N. Shvetsov ◽  
D.L. Skuratov
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Strain Hardening ◽  
Processing Speed ◽  
Synthetic Diamond ◽  
High Strength ◽  
The State ◽  
Diamond Burnishing

The influence of the burnishing force, tool radius, processing speed and feed on the distribution of circumferential and axial residual strses, microhardness and the depth of strain hardening in the surface layer when pr ssing of "30ХГСН2А-ВД" steel with synthetic diamond "ACB-1" is considered. Empirical dependencies determining these parameters are given. Keywords diamond burnishing, strain hardening depth, circumferential residual stresses, axial residual stresses, microhardness. [email protected], [email protected]

Insight into Delivery Approaches for Biopharmaceutics Classification System Class II and IV Drugs

2020 ◽  
Vol 10 (4) ◽  
pp. 255-277
Author(s):  
Shashank Chaturvedi ◽  
Raghav Mishra
Keyword(s):  
Class Ii ◽  
Crystal Habit ◽  
Extensive Literature ◽  
Formulation Development ◽  
Particle Size Reduction ◽  
Bioavailability Enhancement ◽  
Poor Solubility ◽  
Biopharmaceutics Classification System Class ◽  
Poorly Soluble ◽  
Physical And Chemical

: Formulation development of BCS Class II and IV drugs is a challenging task due to their poor solubility and permeability issue. : An extensive literature survey was conducted to explore the relevant pharmaceutical approaches that have been used for solving the issue of poor solubility and permeability in the recent past. : It has been found that a plethora of approaches have been investigated for addressing the issue of poor solubility and or permeability. These include physical modifications (modification of crystal habit, particle size reduction, complexation, polymorphism and drug dispersion in carriers), chemical modifications (salt formation), and formulation modifications (Nanotechnology-based approaches and hydrotropy). : The physical and chemical modification approaches can be effectively used to enhance the solubility and dissolution rate of poorly soluble drugs, but the additional problem of poor permeability has been better addressed by lipid-based drug delivery systems. As the latter presents the drug in the solubilized state, bypass first-pass effects, circumvent the effect of Para-glycoprotein mediated efflux of drugs, hence contributing to overall bioavailability enhancement.

NITROGEN ISOTOPES IN MODERN AND FOSSILIZED CYCAD LEAVES: EVOLUTIONARY AND GEOLOGICAL IMPLICATIONS

2016 ◽  
Author(s):  
Michael Kipp ◽  
◽  
Eva Stüeken ◽  
Roger Buick ◽  
Caroline A.E. Strömberg ◽  
...  
Keyword(s):  
Nitrogen Isotopes ◽  
Geological Implications

NITROGEN ISOTOPES IN MARINE MOLLUSKS AS INDICATORS OF NITROGEN LOADING IN COASTAL NORTH CAROLINA

2018 ◽  
Author(s):  
Hayley I. Bennett ◽  
◽  
David P. Gillikin ◽  
David H. Goodwin ◽  
Elizabeth Cilia ◽  
...  
Keyword(s):  
North Carolina ◽  
Nitrogen Isotopes ◽  
Nitrogen Loading ◽  
Marine Mollusks
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