Spray Chamber Designs and Optical Techniques for Fundamental Spray Investigations

This study concerned the quality of mini-tablets’ coating uniformity obtained by either the bottom spray chamber with a classical Wurster distributor (CW) or a swirl distributor (SW). Mini-tablets with a diameter of 2.0, 2.5, and 3.0 mm were coated with hypromellose using two different inlet air distributors as well as inlet airflow rates (130 and 156 m3/h). Tartrazine was used as a colorant in the coating layer and the coating uniformity was assessed by spectrophotometric analysis of solutions obtained after disintegration of the mini-tablets (n = 100). Higher uniformity of coating material distribution among the mini-tablets was observed in the case of SW distributor, even for the biggest mini-tablets (d = 3.0 mm), with an RSD no larger than 5.0%. Additionally, coating thickness was evaluated by colorimetric analysis (n = 1000), using a scanner method, and expressed as a hue value. A high correlation (R = 0.993) between inter-tablet variability of hue and UV-Vis results was obtained. Mini-tablets were successfully coated in a fluid bed system using both a classical Wurster distributor as well as a swirl generator. However, regardless of the mini-tablets’ diameter, better film uniformity was achieved in the case of a distributor with a swirl generator.

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The Influence of Surface Preparation of the Steel during the Renovation of the Car Body on Its Corrosion Resistance

Coatings ◽

10.3390/coatings11040384 ◽

2021 ◽

Vol 11 (4) ◽

pp. 384

Author(s):

Dariusz Ulbrich ◽

Jakub Kowalczyk ◽

Arkadiusz Stachowiak ◽

Wojciech Sawczuk ◽

Jaroslaw Selech

Keyword(s):

Corrosion Resistance ◽

Glass Bead ◽

Salt Spray ◽

Zinc Coating ◽

Surface Preparation ◽

The Other ◽

Average Thickness ◽

Spray Chamber ◽

Car Body ◽

Abrasive Blasting

The article presents the influence of the applied method used for removing the varnish coat on the corrosion resistance of the car body sheet. The tests were carried out on samples prepared from factory-painted car body elements with pearlescent, metallized and acrylic varnish. Removal of the varnish coat was performed by sandpaper grinding, glass bead blasting, disc blaze rapid stripping, soda blasting and abrasive blasting with plastic granules. The average thickness of the factory-painted coating depending on the type of lacquer ranged from about 99 to 140 µm. On the other hand, after removing the varnish, the thickness of the protective zinc coating ranged from 2 to 12.7 µm. The highest values of the zinc coating were obtained for samples in which the varnish was removed by the method such as soda blasting and abrasive blasting with plastic granules. For these two methods of surface preparation, the damage to the zinc layer protecting the steel against corrosion is the smallest and the percentage of zinc in the surface layer ranges from 58% to 78%. The final stage of the research was to test the samples after removing the varnish coat in a two-hour exposure to the corrosive environment in a salt spray chamber. Samples with the surface prepared by grinding with sandpaper reached the level of surface rusting Ri 5, while in the case of soda blasting and the use of plastic granules, no corrosion centers were observed on the surface of the car body sheet.

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Impact of enhanced optical techniques at time of TURBT with or without single immediate intravesical chemotherapy on recurrence rate of NMIBC, a systematic review and network meta‐analysis of randomized trials

BJU International ◽

10.1111/bju.15383 ◽

2021 ◽

Author(s):

Reza Sari Motlagh ◽

Keiichiro Mori ◽

Ekaterina Laukhtina ◽

Abdulmajeed Aydh ◽

Satoshi Katayama ◽

...

Keyword(s):

Systematic Review ◽

Recurrence Rate ◽

Randomized Trials ◽

Meta Analysis ◽

Intravesical Chemotherapy ◽

Optical Techniques

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An Improved Lagrangian-Inverse Method for Evaluating the Dynamic Constitutive Parameters of Concrete

Materials ◽

10.3390/ma13081871 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1871

Author(s):

Xinlu Yu ◽

Yingqian Fu ◽

Xinlong Dong ◽

Fenghua Zhou ◽

Jianguo Ning

Keyword(s):

High Speed ◽

Inverse Method ◽

Image Correlation ◽

Analysis Method ◽

Stress Strain ◽

Optical Techniques ◽

Element Simulation ◽

Non Linear ◽

Constitutive Parameters ◽

Inverse Analysis Method

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.

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