Search Results

1 - 10 of 58 items :

  • "particle size analysis" x
Clear All
Holocene changes in the conditions of sedimentation in the eastern part of Lake Jamno based on sediment profile JS-64

Abstract

Changes in sedimentological conditions in Lake Jamno during its development throughout the Holocene are presented in this paper. For this purpose, selected granulometric and geochemical parameters were used, which describe the nature and dynamics of the environment, as well as determining primary production capacity and origin of the matter. On the basis of these parameters, the environmental conditions occurring in subsequent stages of lake development were distinguished.

Open access
Synthesis, Characterization and Synthetic Applications of Fly-ash:H3PO4 Nanocatalyst

Abstract

The solid acidic nanocatalyst fly-ash:H3PO4 was prepared and characterized by FT-IR, SEM, EDS and TEM analysis. This catalyst was utilized for aldol condensation, coupling and cyclization reaction. The effect of catalytic activity of this fly-ash:H3PO4 nanocatalyst was studied with the obtained yield of products under solvent-free conditions. In this synthetic reaction the obtained yields were more than 95 %.

Open access
Formulation and optimization of fenofibrate lipospheres using Taguchi’s experimental design

Fenofibrate lipospheres were prepared by the melt dispersion technique. Critical parameters influencing particle size and entrapment efficiency were optimized by applying the L9 Taguchi experimental design. Entrapment efficiency of up to 87 % was obtained for the optimized formulation on increasing olive oil up to 30 % in the lipid carrier. Particle size analysis by microscopy and SEM revealed narrow particle size distribution and formation of discrete lipospheres of superior morphology. In vitro dissolution data best fitted the Higuchi model, indicating diffusion controlled release from porous lipid matrices. Prolonged release was obtained from stearic acid-olive oil lipospheres compared to cetyl alcohol-olive oil lipospheres due to the relatively hydrophobic matrix formed by stearic acid. Lipid lowering studies in Triton induced hyperlipidemia rat model demonstrated higher lipid lowering ability for fenofibrate lipospheres compared to the commercial product and plain drug.

Open access
Polyolefin oxo-degradation accelerators - a new trend to promote environmental protection

Polyolefin oxo-degradation accelerators - a new trend to promote environmental protection

The paper presents the results of the tests on the preparation of iron (III) stearate - the most prominent oxo-biodegradation agent for polyolefinic plastics. The process chosen for testing was the double precipitation process, using stearic acid alkalised with soda lye and iron (III) chloride or iron (III) sulphate. A number of iron (III) stearate preparation methods described in the literature were tested and an analytical procedure for monitoring the process was developed using both the classical and instrumental techniques. FTIR spectroscopy is the most useful technique for the product quality control and identification. During the study the characteristics of the proper product were also determined using the DSC methods. Microscopy and laser diffraction particle size analysis were applied to determine the size of the precipitated product grains. An application sample of the product obtained by the double decomposition method from iron (III) sulphate as the iron carrier has successfully passed the application tests in the polyethylene packaging film.

Open access
Bioadhesive vaginal tablets containing spray dried microspheres loaded with clotrimazole for treatment of vaginal Candidiasis

Abstract

The aim of the present investigation was to prepare and evaluate novel bioadhesive vaginal tablets containing clotrimazole loaded microspheres in order to provide long-term therapeutic activity at the site of infection. Tablets were prepared by incorporating drug loaded microspheres and using bioadhesive polymers hydroxypropylmethylcellulose, sodium carboxymethylcellulose and Carbopol. Microspheres were prepared by the spray drying technique using Eudragit RS-100 and Eudragit RL-100. Microspheres were characterized by SEM, DSC, FTIR, particle size analysis and evaluated for percentage yield, drug loading, encapsulation efficiency and in vitro drug release. To achieve bioadhesion to the mucosal tissue, optimized microspheres were incorporated into bioadhesive tablets and were evaluated for in vitro drug release, in vitro and in vivo mucoadhesion. FTIR and DSC studies showed that no chemical interaction occurred between the drug and polymers. The sphericity factor indicated that the prepared microspheres were spherical. Formulation Mt6 indicated a controlled in vitro drug release and good bioadhesive strength. The in vivo images confirmed the bioadhesion and retention property of tablets up to 24 h. The results indicated that this drug delivery system can be explored for controlled intravaginal drug release.

Open access
Effect of two-stage thermal disintegration on particle size distribution in sewage sludge

distribution on the dewatering of organic sludges. Wat. Sci. Tech. 28 (1), 149-157. 0273-1223193. 5. Neis, U. & Tiehm, A. (1997). Particle size analysis in primary and secondary waste water effluents. Wat. Sci. Tech. 36 (4), 151-158. 6. Tiehm, A., Herwig, V. & Neis, U. (1999). Particle size analysis for improved sedimentation and filtration in waste water treatment. Wat. Sci. Tech. 39 (8), 99-106. 7. Barth, H.G. & Flippen, R.B. (1995). Particle Size Analysis. Anal. Chem , 67(12), 257-272 . Publication Date: June 1995

Open access
Soil grain size analysis by the dynamometer method – a comparison to the pipette and hydrometer method

size in calculating the capacity of water unavailable to plants. Soil Science Annual 66(1): 21–28. Buchan G.D., Grewal K.S., Robson A.B., 1993a. Improved models of particle-size distribution: an illustration of model comparison techniques. Soil Science Society of America Journal 57: 901–908. Buchan G.D., Grewal K.S., Claydon J.J., McPherson R.J., 1993b. A comparison of Sedigraph and pipette methods for soil particle-size analysis. Australian Journal of Soil Research 31(4): 407–417. Buchan G.D., 1989. Applicability of the simple lognormal model to

Open access
Eudragit S-100 coated sodium alginate microspheres of naproxen sodium: Formulation, optimization and in vitro evaluation / Alginatne mikrosfere naproksen natrija obložene Eudragitom S-100: Priprava, optimizacija i in vitro vrednovanje

The aim of the study was to prepare site specific drug delivery of naproxen sodium using sodium alginate and Eudragit S-100 as a mucoadhesive and pH-sensitive polymer, respectively. Core microspheres of alginate were prepared by a modified emulsification method followed by cross-linking with CaCl2, which was further coated with the pH dependent polymer Eudragit S-100 (2.5 or 5 %) to prevent drug release in the upper gastrointestinal environment. Microspheres were characterized by FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and evaluated by scanning electron microscopy, particle size analysis, drug loading efficiency, in vitro mucoadhesive time study and in vitro drug release study in different simulated gastric fluids. Stability studies of the optimized formulation were carried out for 6 months. SEM images revealed that the surface morphology was rough and smooth for core and coated microspheres, respectively. Core microspheres showed better mucoadhesion compared to coated microspheres when applied to the mucosal surface of freshly excised goat colon. The optimized batch of core microspheres and coated microspheres exhibited 98.42 ± 0.96 and 95.58 ± 0.74 % drug release, respectively. Drug release from all sodium alginate microsphere formulations followed Higuchi kinetics. Moreover, drug release from Eudragit S-100 coated microspheres followed the Korsmeyer-Peppas equation with a Fickian kinetics mechanism. Stability study suggested that the degradation rate constant of microspheres was minimal, indicating 2 years shelf life of the formulation.

Open access
Measurement of activated sludge particle diameters using laser diffraction method / Pomiary średnicy cząstek osadu czynnego za pomocą metody dyfrakcji laserowej

. Retention and removal of pathogenic bacteria in wastewater percolating through porous media: a review. Water Res. 2004;38:1355-1367. DOI: 10.1016/j.watres.2003.12.024. [22] Hopkins BM. A quantitative image analysis system. Opt Eng. 1976;15:236-240. [23] Barbusiński K, Kościelniak H. Influence of substrate loading intensity on flock size in activated sludge process. Water Res. 1995;29(7):1703-1710. [24] Neis U, Tiehm A. Particle size analysis in primary and secondary waste water effluents. Water Sci Technol. 1997

Open access
Analysis of particle size and fractal dimensions of suspensions contained in raw sewage, treated sewage and activated sludge

. Jaffrin M.Y. Gupta B. Paullier P. Geaugey V. 2000 Contribution of various constituents of activated sludge to membrane bioreactor fouling Bioresource Technology 73 2 105 112 Garcia–Mesa, J.J., Delgado-Ramos, F., Muñio, M.M., Hontoria, E. & Poyatos, J.M. (2012). Comparison of activated sludge technologies by particle size analysis, Water Air and Soil Pollution , 223, pp. 4319–4331. Garcia–Mesa J.J. Delgado-Ramos F. Muñio M.M. Hontoria E. Poyatos J.M. 2012 Comparison of activated sludge technologies by particle size

Open access