Development of a Particle Sizing Algorithm for Sub-10µm Particles Using Shadowgraphy

Author(s):  
Michael Robinson ◽  
Zakaria Mahmud ◽  
Orven F. Swenson ◽  
Justin Hoey

We developed a Small Particle Sizing Algorithm (SPSA) that utilizes Fresnel and Fraunhofer diffraction profiles to determine sizes of small spherical particles from 1 to 10 μm in diameter. The SPSA uses standard shadowgraphy techniques to generate an image of the diffraction profile from which two characteristic parameters are measured, image size and image slope. Over specified ranges, the combinations of these parameters are unique, enabling the simultaneous calculation of particle size and distance from the object plane of the CCD camera.

2006 ◽  
Vol 972 ◽  
Author(s):  
Atsuo Yamada ◽  
Shinichi Nishimura ◽  
Hiroshi Koizumi ◽  
Ryoji Kanno ◽  
Shiro Seki ◽  
...  

AbstractRietveld analysis for the time of flight powder neutron diffraction profile for LiFePO4 at room temperature was performed. Refined tensor elements of the unisotropic thermal factor under the elliptic approximation showed the principal axis of the lithium vibration is toward the face shared vacant tetrahedral space and is consistent with the theoretical prediction; lithium ions diffuse along curved one-dementional chain along b-axis. Impact of temperature on the phase diagram of LixFePO4 with > 200nm particle size was slight under the unmixing line around 200 C. While the reduction in particle size down to <100 nm seems to have significant effect to the room temperature miscibility gap. The thermodynamic concepts for the extended solution in smaller particles are discussed, followed by a demonstration of very high rate capability observed for the small spherical particles < 80 nm.


2011 ◽  
Vol 411 ◽  
pp. 193-197
Author(s):  
Hong Tang ◽  
Wen Bin Zheng

In light extinction particle sizing, a classification inversion algorithm is proposed for the non-spherical particles. The measured spheroidal particle system is inversed with different particle distribution functions and classified according to the inversion errors in the dependent model. Simulation experiments illustrate that it is feasible to use the inversion errors to inverse the spheroidal particle size distribution in the light extinction particle sizing technique and the inversion results are steady and reliable, which avoid the defects that the type of the size distribution must be assumed beforehand for the light extinction method.


2020 ◽  
Vol 14 (3) ◽  
pp. 210-224
Author(s):  
Gayatri Patel ◽  
Bindu K.N. Yadav

Background: The purpose of this study was to formulate, characterize and in-vitro cytotoxicity of 5-Fluorouracil loaded controlled release nanoparticles for the treatment of skin cancer. The patents on nanoparticles (US8414926B1), (US61654404A), (WO2007150075A3) etc. helped in the selection polymers and method for the preparation of nanoparticles. Methods: In the present study nanoparticles were prepared by simple ionic gelation method using various concentrations of chitosan and sodium tripolyphosphate (TPP). Several process and formulation parameters were screened and optimized using 25-2 fractional factorial design. The prepared nanoparticles were evaluated for particle size, shape, charge, entrapment efficiency, crosslinking mechanism and drug release study. Results: The optimized 5-Fluorouracil loaded nanoparticle were found with particle size of of 320±2.1 nm, entrapment efficiency of 85.12%± 1.1% and Zeta potential of 29mv±1mv. Scanning electron microscopy and dynamic light scattering technique revealed spherical particles with uniform size. The invitro release profile showed controlled release up to 24 hr. Further study was carried using A375 basal cell carcinoma cell-line to elucidate the mechanism of its cytotoxicity by MTT assay. Conclusion: These results demonstrate that the possibility of delivering 5-Fluorouracil to skin with enhanced encapsulation efficiency indicating effectiveness of the formulation for treatment of basal cell carcinoma type of skin cancer.


Author(s):  
Dr. Jambla Neha ◽  
Saroch Vikas ◽  
Johar Smita

Rasashastra deals with the Rasa Aushadhis, the drugs of metallic and mineral origin. Mercury is used in most of the Rasaaushadhis. The toxicity of Mineral and metallic preparations are reduced to such an extent by various procedures of Shodhana, Marana etc. that Mercury converts its inherent property of toxicity into medicinal property. Rasa Aushadhis works quickly on the body because due to their small particle size, their absorption starts from the oral mucosa itself. The action of drugs depends largely upon the Anupana i.e. the vehicle for the drug. Rasacharayas have mentioned various Rasa preparations like Bhasmas, Parpati, Pottali, Manduras, Karpooras etc. along with their doses, dose schedule and Anupana / Sahapana etc. The principles of Rasaaushadhis when correlated in modern era are found to be scientifically accurate. We may say that Rasacharyas had already mastered the science of nanotechnology, purification, action of metabolic catalysts, biotransformation and preservation of medicines. The Ayurvedic drugs can be harmful for our body when not administered in proper dosage as per mentioned in classic literatures.


RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1952-1959
Author(s):  
Yi Zhao ◽  
Fangfang Peng ◽  
Yangchuan Ke

Emulsion with small particle size and good stability stabilized by emulsifiers was successfully prepared for EOR application.


Author(s):  
Adam C. Gladen ◽  
Susan C. Mantell ◽  
Jane H. Davidson

A thermotropic material is modeled as an absorbing, thin slab containing anisotropic scattering, monodisperse, spherical particles. Monte Carlo ray tracing is used to solve the governing equation of radiative transfer. Predicted results are validated by comparison to the measured normal-hemispherical reflectance and transmittance of samples with various volume fraction and relative index of refraction. A parametric study elucidates the effects of particle size parameter, scattering albedo, and optical thickness on the normal-hemispherical transmittance, reflectance, and absorptance. The results are interpreted for a thermotropic material used for overheat protection of a polymer solar absorber. For the preferred particle size parameter of 2, the optical thickness should be less than 0.3 to ensure high transmittance in the clear state. To significantly reduce the transmittance and increase the reflectance in the translucent state, the optical thickness should be greater than 2.5 and the scattering albedo should be greater than 0.995. For optical thickness greater than 5, the reflectance is asymptotic and any further reduction in transmittance is through increased absorptance. A case study is used to illustrate how the parametric study can be used to guide the design of thermotropic materials. Low molecular weighted polyethylene in poly(methyl methacrylate) is identified as a potential thermotropic material. For this material and a particle radius of 200 nm, it is determined that the volume fraction and thickness should equal 10% and 1 mm, respectively.


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