SPHERULITIC GROWTH IN PROTEIN SOLUTIONS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 354-358 ◽  
Author(s):  
PUI SHAN CHOW ◽  
JING ZHANG ◽  
XIANG YANG LIU ◽  
REGINALD BENG HEE TAN
Keyword(s):  
Sodium Chloride ◽  
Growth Process ◽  
Polarized Light ◽  
Optical Microscope ◽  
Model System ◽  
Protein Solutions ◽  
Protein Solution ◽  
Liquid Separation ◽  
Spherulitic Growth ◽  
Crystal Growth Process

Lysozyme was chosen as a model system for investigation of spherulitic growth in protein solution. Solutions of various concentrations of lysozyme and sodium chloride were studied under an optical microscope using polarized light. Spherulites were observed in the liquid-liquid separation regime. Images at various stages during the crystal growth process are presented. In a separate set of experiments, it was demonstrated that the presence of foreign particles could promote spherulitic growth even without liquid-liquid separation.

Investigation of Carbon Inclusions in SiC Crystals Grown by PVT Method

2020 ◽  
Vol 1004 ◽  
pp. 20-25
Author(s):  
Xue Jian Xie ◽  
Jin Ying Yu ◽  
Xiang Long Yang ◽  
Xiu Fang Chen ◽  
Xian Gang Xu ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Formation Mechanism ◽  
Growth Process ◽  
Optical Microscope ◽  
Bulk Crystals ◽  
Crystal Growth Process

The carbon inclusions in SiC bulk crystals were studied by using optical microscope. The carbon inclusions were classified into three types, namely Type Ⅰ (100~1000 μm), Type Ⅱ (20~50 μm), Type Ⅲ (~5 μm) carbon inclusions based on their different morphologies. In addition, the evolution of these three type carbon inclusions with crystal growth process was traced. It was found that the number of Type Ⅰ and Type Ⅱ carbon inclusions showed declined tendency with crystal growth, while the number of Type Ⅲ carbon inclusions exhibited less dependence on crystal growth. Furthermore, the formation mechanism of carbon inclusions was clarified. This study would give out a better understanding of carbon inclusions, thus contribute to reducing or eliminating carbon inclusions in SiC crystals.

Instability of thermocapillary–buoyancy convection in shallow layers. Part 2. Suppression of hydrothermal waves

1998 ◽  
Vol 359 ◽  
pp. 165-180 ◽  
Author(s):  
S. BENZ ◽  
P. HINTZ ◽  
R. J. RILEY ◽  
G. P. NEITZEL
Keyword(s):  
Free Surface ◽  
Crystal Growth ◽  
Growth Process ◽  
Thermocapillary Convection ◽  
Model System ◽  
Wave Instability ◽  
Float Zone ◽  
Crystal Growth Process ◽  
Hydrothermal Wave ◽  
Buoyancy Convection

Hydrothermal-wave instabilities in thermocapillary convection are known to produce undesirable effects when they occur during the float-zone crystal-growth process, and perhaps in other situations. Suppression of the hydrothermal-wave instability produced in the model system of Part 1 (Riley & Neitzel 1998) is demonstrated through the sensing of free-surface temperature perturbations and the periodic addition of heat at the free surface along lines parallel to the crests of the hydrothermal waves.

scholarly journals Dendrite Pattern Formation of Sodium Chloride Crystal

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4434
Author(s):  
Nobuhiko J. Suematsu ◽  
Junpei Iwamoto ◽  
Yuya Ishii ◽  
Akira Yamamoto
Keyword(s):  
Crystal Growth ◽  
Sodium Chloride ◽  
Pattern Formation ◽  
Growth Process ◽  
Molecular Structures ◽  
Nacl Solution ◽  
Dendrite Structure ◽  
Detailed Mechanism ◽  
Crystal Growth Process ◽  
Equilibrium Structures

A variety of crystal structures is found in nature, not only equilibrium structures reflecting molecular structures, but also non-equilibrium structures which depend on the physicochemical conditions occurring during the crystal growth. In this paper, we focus on the dendrite structure of sodium chloride (NaCl) formed by the simple evaporation of an aqueous NaCl solution. The characteristics of the growth structures were measured as a function of the initial concentration of NaCl. In addition, the crystal growth process was measured using optical microscopy. As a result, the growth rate was not constant but was found to oscillate over time and synchronize with the wetting of the crystal. Our observations indicate that dendrite structures are more easily generated at higher initial concentrations. The detailed mechanism for dendrite pattern formation is still under investigation.

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

scholarly journals The Different Colors of mAbs in Solution

Antibodies ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 21
Author(s):  
Alexandre Ambrogelly
Keyword(s):  
Visual Inspection ◽  
Quantitative Methods ◽  
Geographical Area ◽  
Therapeutic Protein ◽  
Protein Solutions ◽  
Protein Solution ◽  
Critical Quality Attribute ◽  
Recombinant Therapeutic Protein ◽  
Protein Variants ◽  
Antibody Solution

The color of a therapeutic monoclonal antibody solution is a critical quality attribute. Consistency of color is typically assessed at time of release and during stability studies against preset criteria for late stage clinical and commercial products. A therapeutic protein solution’s color may be determined by visual inspection or by more quantitative methods as per the different geographical area compendia. The nature and intensity of the color of a therapeutic protein solution is typically determined relative to calibrated standards. This review covers the analytical methodologies used for determining the color of a protein solution and presents an overview of protein variants and impurities known to contribute to colored recombinant therapeutic protein solutions.

scholarly journals Crystallization Behavior and Mechanical Properties of Poly(ε-caprolactone) Reinforced with Barium Sulfate Submicron Particles

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2368
Author(s):  
Hegoi Amestoy ◽  
Paul Diego ◽  
Emilio Meaurio ◽  
Jone Muñoz ◽  
Jose-Ramon Sarasua
Keyword(s):  
Barium Sulfate ◽  
Thermal Studies ◽  
Polarized Light ◽  
Optical Microscope ◽  
Submicron Particles ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Nucleation Effect ◽  
Crystal Fraction ◽  
Light Optical Microscope

Poly(ε-caprolactone) (PCL) was mixed with submicron particles of barium sulfate to obtain biodegradable radiopaque composites. X-ray images comparing with aluminum samples show that 15 wt.% barium sulfate (BaSO4) is sufficient to present radiopacity. Thermal studies by differential scanning calorimetry (DSC) show a statistically significant increase in PCL degree of crystallinity from 46% to 52% for 25 wt.% BaSO4. Non-isothermal crystallization tests were performed at different cooling rates to evaluate crystallization kinetics. The nucleation effect of BaSO4 was found to change the morphology and quantity of the primary crystals of PCL, which was also corroborated by the use of a polarized light optical microscope (PLOM). These results fit well with Avrami–Ozawa–Jeziorny model and show a secondary crystallization that contributes to an increase in crystal fraction with internal structure reorganization. The addition of barium sulfate particles in composite formulations with PCL improves stiffness but not strength for all compositions due to possible cavitation effects induced by debonding of reinforcement interphase.

Experimental Verification of the Numerical Model for a CaF2 Crystal Growth Process

2002 ◽  
Vol 37 (1) ◽  
pp. 77-82 ◽  
Author(s):  
A. Molchanov ◽  
U. Hilburger ◽  
J. Friedrich ◽  
M. Finkbeiner ◽  
G. Wehrhan ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Numerical Model ◽  
Experimental Verification ◽  
Growth Process ◽  
Caf2 Crystal ◽  
Crystal Growth Process
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