scholarly journals Coating effect of micro-sized droplets impacting on low temperature spherical particles

2018 ◽  
Author(s):  
Zhanyong Li ◽  
Xiusheng Wu ◽  
Xiaoyu Ma ◽  
Qing Xu ◽  
Ruifang Wang
Keyword(s):  
Low Temperature ◽  
Freeze Drying ◽  
Orthogonal Design ◽  
Particle Temperature ◽  
Spherical Particles ◽  
Design Experiment ◽  
High Definition ◽  
Before And After ◽  
Spray Freeze Drying ◽  
Precision Balance

In this paper, the effect of spray droplets on the coating of cold spherical particles was studied.The microcapsule granulator produces micron-sized droplets to coat the spherical particles in cold storage, and the high-definition camera and precision balance are used to photograph and weigh the particles before and after the spraying. The droplets are obtained by using the image and data processing technology coating area and coating quality, the droplet coating effect was evaluated by a number of dimensionless parameters such as coating ratio and mass ratio.By orthogonal design experiment and uncertainty analysis, the effects of droplet size and flow rate, spherical particle temperature and diameter on coating effect were studied, and the effect of droplet group coating on low temperature spherical particles was obtained. Keywords: Spray freeze drying; Droplets; Coating; Spherical particles. 

scholarly journals Evaluation of Process Conditions for Ultrasonic Spray-Freeze Drying of Transglutaminase

2020 ◽  
Vol 58 (1) ◽  
pp. 38-48
Author(s):  
Hilal Isleroglu ◽  
Izzet Turker
Keyword(s):  
Enzyme Activity ◽  
Flow Rate ◽  
Freeze Drying ◽  
Desirability Function ◽  
Spherical Particles ◽  
Optimum Process ◽  
Process Conditions ◽  
Plate Temperature ◽  
Ultrasonic Spray ◽  
Spray Freeze Drying

In this study, a commercial transglutaminase enzyme was dried using an ultrasonic spray freeze drying method and the effects of the process conditions were optimized to maximize the final transglutaminase activity. Accordingly, process parameters affecting enzyme activity were selected, such as nozzle frequency (48 and 120 kHz), flow rate (2, 5 and 8 mL/min) and plate temperature for secondary drying (25, 35 and 45 °C). Moreover, the effects of different pH values (pH=2.0 and 9.0) and high temperature (80 °C) on enzyme activity, physical properties and particle morphology of transglutaminase were discussed. According to the results, transglutaminase preserved its activity despite ultrasonic spray freeze drying. Sonication enhanced the enzyme activity. Using the desirability function method, the optimum process conditions were determined to be flow rate 3.10 mL/min, plate temperature 45 °C and nozzle frequency 120 kHz. The predicted activity ratio was 1.17, and experimentally obtained ratio was 1.14±0.02. Furthermore, enzyme produced by ultrasonic spray freeze drying had low moisture values (2.92-4.36 %) at 8 h of drying. When the morphological structure of the transglutaminase particles produced by ultrasonic spray freeze drying under the optimum conditions was examined, spherical particles with pores on their surfaces were observed. In addition, flow properties of the transglutaminase powders were considered as fair under most conditions according to the Carr index.

scholarly journals Intratracheal inoculation of AHc vaccine induces protection against aerosolized botulinum neurotoxin A challenge in mice

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Changjiao Gan ◽  
Wenbo Luo ◽  
Yunzhou Yu ◽  
Zhouguang Jiao ◽  
Sha Li ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Clostridium Botulinum ◽  
Freeze Drying ◽  
Botulinum Neurotoxin ◽  
Secretory Iga ◽  
Immune Protection ◽  
Dry Powder ◽  
Botulinum Neurotoxin A ◽  
Spray Freeze Drying

AbstractBotulinum neurotoxin (BoNT), produced by Clostridium botulinum, is generally known to be the most poisonous of all biological toxins. In this study, we evaluate the protection conferred by intratracheal (i.t.) inoculation immunization with recombinant Hc subunit (AHc) vaccines against aerosolized BoNT/A intoxication. Three AHc vaccine formulations, i.e., conventional liquid, dry powder produced by spray freeze drying, and AHc dry powder reconstituted in water are prepared, and mice are immunized via i.t. inoculation or subcutaneous (s.c.) injection. Compared with s.c.-AHc-immunized mice, i.t.-AHc-immunized mice exhibit a slightly stronger protection against a challenge with 30,000× LD50 aerosolized BoNT/A. Of note, only i.t.-AHc induces a significantly higher level of toxin-neutralizing mucosal secretory IgA (SIgA) production in the bronchoalveolar lavage of mice. In conclusion, our study demonstrates that the immune protection conferred by the three formulations of AHc is comparable, while i.t. immunization of AHc is superior to s.c. immunization against aerosolized BoNT/A intoxication.

scholarly journals Post-Processing Techniques for the Improvement of Liposome Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1023
Author(s):  
Ji Young Yu ◽  
Piyanan Chuesiang ◽  
Gye Hwa Shin ◽  
Hyun Jin Park
Keyword(s):  
Freeze Drying ◽  
Protective Agent ◽  
Post Processing ◽  
Additional Process ◽  
Spray Freeze Drying ◽  
The Stability ◽  
Processing Techniques ◽  
The Impact ◽  
Self Aggregation ◽  
Liposome Stability

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Environmental Influence on the Tolerance of Corn to Atrazine

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Lafayette Thompson ◽  
F. W. Slife ◽  
H. S. Butler
Keyword(s):  
Zea Mays ◽  
High Temperature ◽  
Low Temperature ◽  
Light Intensity ◽  
Environmental Influence ◽  
High Light Intensity ◽  
High Light ◽  
Growth Chamber ◽  
Peptide Conjugates ◽  
Before And After

Corn(Zea maysL.) in the two to three-leaf stage grown 18 to 21 days in a growth chamber under cold, wet conditions was injured by postemergence application of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) plus emulsifiable phytobland oil. Injury was most severe when these plants were kept under cold, wet conditions for 48 hr after the herbicidal spray was applied, followed by exposure to high light intensity and high temperature. Under these growth chamber conditions, approximately 50% of the atrazine-treated plants died. Since wet foliage before and after application increased foliar penetration and low temperature decreased the rate of detoxication to peptide conjugates, atrazine accumulated under cold, wet conditions. This accumulation of foliarly-absorbed atrazine and the “weakened” conditions of the plants grown under the stress conditions is believed to be responsible for the injury to corn. Hydroxylation and the dihydroxybenzoxazin-3-one content in the roots were reduced at low temperature, but it is unlikely that this contributed to the death of the corn.

Investigation of the properties of knitted woolen fabrics treated with oxygen low-temperature plasma for sportswear applications

2021 ◽  
pp. 004051752110306
Author(s):  
Honglian Cong ◽  
Boyu Zhao ◽  
Hao Han ◽  
Xuliang Yu
Keyword(s):  
Low Temperature ◽  
Plasma Treatment ◽  
Moisture Absorption ◽  
Mapping Method ◽  
Function Evaluation ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Wool Fibers ◽  
Before And After ◽  
Concentration Mapping

Nine groups of knitted woolen fabrics for sportswear with different technical characteristics were treated with oxygen low-temperature plasma, and the changes in the surface morphology and chemical composition of wool fibers before and after plasma treatment, as well as the changes in the applicability indexes of knitted woolen fabrics, were studied. Finally, the comfort performance of the fabrics was evaluated by combining the concentration mapping method and the function evaluation value method. The analysis found that the surface scales of wool fibers were seriously etched after oxygen low-temperature plasma treatment, and the anti-felting, bursting strength and moisture absorption of the knitted woolen fabrics were improved. At the same time, the quick-drying index of the fabric has also been improved to a certain extent. This research provides a basis for the development of knitted woolen fabric for sportswear with excellent performance.

scholarly journals A low-temperature hydrothermal synthesis of submicron spherical BaF2

RSC Advances ◽  
2021 ◽  
Vol 11 (63) ◽  
pp. 40051-40058
Author(s):  
Xiao Li ◽  
Yuxiang Zhao ◽  
Bo Li ◽  
Shuxuan Wang ◽  
Xingwu Zou
Keyword(s):  
Hydrothermal Synthesis ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Self Assembly ◽  
The Self ◽  
Spherical Particles

BaF2 submicron spherical particles, formed by the self-assembly of nanocubes, were prepared by a low-temperature hydrothermal method with the aid of EDTA-2Na.

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