Search

Results of the experiments on drying of skin-forming material sprayed with two nozzles in counter-current pilot spray dryer are presented in the article. Phase Doppler Anemometry (PDA) measurements were conducted above, between, and below two nozzles spraying upward and downward which allowed us to track changes of particle size distribution (PSD) and particle velocities in the tower for different nozzle configurations. The analysis of PSD shows that for two nozzles pointing downwards, the drying zone was observed under the lower nozzle whereas the agglomeration zone develops between nozzles. For the upward orientation of the lower nozzle, a zone of simultaneous drying and agglomeration forms between the nozzles. Analysis of product moisture content, PSD, and bulk density showed the effect of nozzle configuration on product properties. [ABSTRACT FROM AUTHOR]

Pelvic organ disorders affect up to one in four women in the United States. The prevalence of pelvic organ prolapse (POP) is increasing with each year, particularly in the setting of prolonged life expectancy and an aging population. Current treatment approaches, including polypropylene monofilaments are associated with numerous painful and worrisome side-effects. Therefore, scientists are looking for new solutions. A promising alternative to the current treatment is tissue engineering, which can be utilized to re-create support to the vagina and pelvic organs. Tissue engineering requires the use of three-dimensional scaffolds, derived from biocompatible materials. Chitosan is a natural polymer, obtained from shellfish exoskeletons. It is known for its biodegradability, lack of cytotoxicity and non-pyrogenicity. Due to the presence of free hydroxyl and amino groups, it may undergo various modifications. In this paper, we describe a new type of chitosan-based biomaterials, which can be used as a new alternative scaffold that may provide support to prolapse organs. The chitosan scaffold was obtained under microwave radiation using multifunctional amino and organic acids. We discuss the scaffold’s characteristics, with an emphasis on its chemical structure and morphology. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed cross-linking processes with preservation of free amino groups. Moreover, mechanical durability, the stability and swelling ability of the scaffolds in a simulated body fluid were investigated. All of the prepared scaffolds demonstrated very good antioxidant activity and biodegradability. Importantly, the biocompatibility of chitosan scaffolds was examined on human vaginal VK2/E6E7 cell line. No evidence of toxicity was documented, and the cells maintained their presence on the studied materials. These results allude to the lack of toxicity of the scaffolds, and indicate that chitosan-based scaffold should be further investigated in in vivo studies as they may be a promising alternative treatment to pelvic organ prolapse. [ABSTRACT FROM AUTHOR]

The work presents the fundamental research of dispersed phase flow during flame spray drying. Particle dynamics analysis and laser Doppler anemometry technique were applied to determine particle size distribution and particle velocity distribution. Results of the study showed that stable combustion and longer length of the flame were observed for coarse spray (large droplets, low atomization pressure, small spraying angle, and low concentration of droplets in spray). Particle residence time in the combustion zone is the main factor affecting the increase in particle diameters due to puffing. Complex flow dynamics of dispersed phase observed at the outward regions of the flame in recirculation zones results in the formation of particle agglomerates. [ABSTRACT FROM AUTHOR]

The work presents the comparison of two spray drying techniques: conventional concurrent spray drying and novel spray drying technique; that is, flame spray drying (FSD) in terms of energy consumption and quality of final product. The amount of energy consumed to dry maltodextrin solutions showed that for similar moisture evaporation rate and equivalent operating parameters of the drying process, energy consumption was 5 to 30% lower in the FSD process. FSD produced lower bulk and apparent densities of maltodextrin powder and, due to shorter drying time, lower content of fractured particles in comparison with the classical spray drying process. [ABSTRACT FROM PUBLISHER]

This article presents results of preliminary studies on a novel spray drying method; i.e., spray drying with a simultaneous ignition of a sprayed medium, termed Flame Spray Drying (FSD). Preliminary FSD trials were carried out to determine the concentration of a flammable spray component at which flame could be initiated and combustion process sustained for two materials with different thermal sensitivity (i.e., maltodextrin and ceramic powder) and two flammable components: ethyl alcohol and sunflower oil. The analysis of temperature distributions in the atomization/flame zone shows significant differences in the evaporation rate for different fuels. Combustion of ethyl alcohol results in higher temperatures and a 0.5 to 1.0 m shorter combustion/evaporation zone in relation to the flame formed with the sunflower oil. Puffing and robust agglomeration of particles and partial caramelization of some powders was observed as a result of an intensive heat and mass transfer in the flame zone. [ABSTRACT FROM PUBLISHER]

The main aim of the study presented in this article was to develop and test a method to determine spray-drying kinetics in a laboratory scale. A special measuring tunnel to obtain evaporation rate similar to the conditions observed in a spray-drying column was designed, built and tested. Extensive studies of drying kinetics for maltodextrin were performed for different air flow rates and air temperatures. Test runs to determine repeatability of this technique showed satisfactory agreement between subsequent measurements, which confirms accuracy of the developed measuring method. An effect of the initial moisture content on the critical moisture content was observed which is related to a decrease of the equilibrium vapor pressure over the solution and a decrease of the driving force of evaporation and drying rate of the process. Results of the experiments proved that the generalized drying curve obtained from small-scale experiments could be used to describe spray-drying kinetics if the critical moisture content of the material is known. [ABSTRACT FROM AUTHOR]

The studies included 110 patients (33 men and 77 women, aged 28 – 65 years) treated because of rheumatoid arthritis (RA). All patients were treated cryogenically. The patients' material studied was analyzed in relation to selected clinical trails: sex, age, duration and progression of the disease, considering the changes of the magnesium concentration in plasma and in erythrocytes registered before and after the end of the cryogenic treatment. The results obtained showed that the development of RA is associated with magnesium deficiency in plasma as well as in erythrocytes. The nearly formed disturbances of the magnesium metabolism depend on sex and age of the patients as well as on the disease duration and progression. Moreover, it was confirmed that in the majority of patients suffering from RA, the systemic cryotherapy only causes statistically insignificant magnesium shifts between the intracellular (erythrocyte) and extracellular (plasma) space. Among the patients suffering from rheumatoid arthritis, there exists, however, a group of persons particularly exposed to magnesium deficiencies in plasma and erythrocytes, which is made-up of women above 50 years of age, in whom the disease lasts over five years, entering the period of destructive changes. In these patients, the cryogenic treatment leads to a further statistically significant disease of the magnesium concentration in the intracellular (erythrocyte) as well as in the extracellular (plasma) space. [ABSTRACT FROM AUTHOR]