scholarly journals Assessment of Mini-Tablets Coating Uniformity as a Function of Fluid Bed Coater Inlet Conditions

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 746
Author(s):  
Magdalena Turk ◽  
Rok Šibanc ◽  
Rok Dreu ◽  
Maja Frankiewicz ◽  
Małgorzata Sznitowska
Keyword(s):  
Coating Layer ◽  
Spectrophotometric Analysis ◽  
Material Distribution ◽  
Spray Chamber ◽  
Colorimetric Analysis ◽  
Swirl Generator ◽  
Coating Uniformity ◽  
Fluid Bed ◽  
Inlet Conditions

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.

scholarly journals Back-trap mottle: A review of mechanisms and possible solutions

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6426-6447
Author(s):  
Hak Lae Lee ◽  
Hye Jung Youn ◽  
Ming He ◽  
Jiachuan Chen
Keyword(s):  
Coating Layer ◽  
Offset Printing ◽  
Coating Structure ◽  
Paper Substrate ◽  
Coated Paper ◽  
Printing Process ◽  
Coated Papers ◽  
Coating Uniformity ◽  
Color Density

Print mottle is a serious and common uneven printing defect that occurs when printing coated paper by the offset multicolor printing process. It is characterized by a non-uniform appearance in terms of brightness, gloss, or color density that appears mostly in solid printed areas. Back-trap print mottle and water-interference print mottle occur when the quality of the paper substrate, especially the coating layer quality, is not satisfactory. To cope with this quality problem of coated papers, the understanding of the offset printing process, the requirements of coated-paper quality, and the reasons for this problem should be addressed. In this review, the basic process of offset printing and the mechanisms of print mottles were explored, the importance of coating uniformity in both the coating structure and process was reviewed, and the approaches to cope with print mottle were introduced.

scholarly journals Spectrophotometric Analysis of the Resazurin Reduction Test as a Tool for Assessing Canine Semen Quality

2013 ◽  
Vol 57 (2) ◽  
pp. 281-285 ◽  
Author(s):  
Rafał Strzeżek ◽  
Krystyna Filipowicz ◽  
Marta Stańczak ◽  
Władysław Kordan
Keyword(s):  
Sperm Motility ◽  
Seminal Plasma ◽  
Semen Quality ◽  
Membrane Integrity ◽  
Spectrophotometric Analysis ◽  
Normal Morphology ◽  
Additional Tool ◽  
Reduction Test ◽  
Highly Correlated

Abstract The resazurin reduction test (RRT) was subjected to spectrophotometric analysis to evaluate the quality of canine semen. Twenty four samples of canine semen were analysed. The absorption peaks for resazurin and resorufin were determined at 615 and 580 nm, respectively. The RRT ratio (RRTsperm-the ratio for samples containing spermatozoa, RRTplasma-the ratio for samples containing seminal plasma) was calculated by dividing the absorbance at 580 nm by the absorbance at 615 nm. Spearman’s correlation test was used to determine the significance of correlations between the analysed sperm parameters and the results of the resazurin reduction assay. The RRT ratio was highly correlated with sperm motility (r=0.68, P<0.01), progressive sperm motility (r=0.61, P<0.01), the subpopulation of cells with rapid velocity (r=0.72, P<0.01), and the subpopulation of cells with medium velocity (r= -0.54, P<0.05). A negative correlation was observed between the reducing capacity of seminal plasma vs. sperm with plasma membrane integrity (r= -0.60, P<0.01) and sperm with normal morphology (r= -0.58, P<0.01). The RRT test can be used as an additional tool for evaluation of the quality of canine semen.

scholarly journals Assessment of the Quality of Frozen Serum by Spectrophotometric Analysis and Sperm Bioassay

1997 ◽  
Vol 39 (2) ◽  
pp. 119-125
Author(s):  
A. M. Hossain ◽  
S. Barik ◽  
B. Rizk ◽  
I. H. Thorneycroft
Keyword(s):  
Spectrophotometric Analysis

Investigation of Lean Premixed Swirl-Stabilized Hydrogen Burner With Axial Air Injection Using OH-PLIF Imaging

2015 ◽  
Author(s):  
Thoralf G. Reichel ◽  
Katharina Goeckeler ◽  
Oliver Paschereit
Keyword(s):  
Flame Front ◽  
Gas Turbines ◽  
Equivalence Ratio ◽  
Vortex Breakdown ◽  
Detection Algorithm ◽  
Air Injection ◽  
Swirl Generator ◽  
Air Jet ◽  
Lean Premixed ◽  
Inlet Conditions

In the context of lean premixed combustion, the prevention of upstream flame propagation in the premixing zone, referred to as flashback, is a crucial challenge related to the application of hydrogen as a fuel for gas turbines. The location of flame anchoring and its impact on flashback tendencies in a technically premixed, swirl-stabilized hydrogen burner are investigated experimentally at atmospheric pressure conditions using planar laser-induced fluorescence of hydroxyl radicals (OH-PLIF). The inlet conditions are systematically varied with respect to equivalence ratio (ϕ = 0.2–1.0), bulk air velocity u0 = 30–90m/s and burner preheat temperature ranging from 300K to 700K. The burner is mounted in the atmospheric combustion test rig at the HFI, firing at a power of up to 220 kW into a 105 mm diameter quartz cylinder, which provides optical access to the flame region. The experiments were performed using an in-house burner design that previously proved to be highly resistant against flashback occurrence by applying the axial air injection strategy. Axial air injection constitutes a non-swirling air jet on the central axis of the radial swirl generator, thus, influencing the vortex breakdown position. High axial air injection yields excellent flashback resistance and is used to investigate the whole inlet parameter space. In order to trigger flashback, the amount of axially injected air is reduced, which allowed to investigate the near flashback flame behavior. Results show that both, fuel momentum of hydrogen and axial air injection alter the isothermal flow field and cause a downstream shift of the axial flame front location. Such a shift is proven beneficial for flashback resistance. This effect was quantified by applying an edge detection algorithm to the OH-PLIF images, in order to extract the location of maximum flame front likelihood xF. The temperature and equivalence ratio dependence of the parameters xF is identified to be governed by the momentum ratio between fuel and air flow J. These results contribute to the understanding of the superior flashback limits of configurations applying high amounts of axial air injection over medium or none air injection.

scholarly journals Influence of temperature and time factor on process of spraying of metallic powders in a plasma atomizer

2020 ◽  
Vol 221 ◽  
pp. 02003
Author(s):  
Sergey Ermakov ◽  
Evgeny Gyulikhandanov ◽  
Evgeny Petukhov
Keyword(s):  
Mathematical Modelling ◽  
Industrial Production ◽  
Additive Technologies ◽  
Time Factor ◽  
Chemical Compositions ◽  
Metal Powders ◽  
Spray Chamber ◽  
Commercial Products ◽  
Influence Of Temperature

The development of additive technologies is hampered by the almost complete absence of domestic systems for the production of metal powders. A prototype installation of a plasma atomizer was developed and manufactured, which makes it possible to obtain low-tonnage batches of metal powders of various chemical compositions. However, when the technology was transferred from the laboratory to production, a number of additional issues arose associated with a decrease in the quality of commercial products as the time of continuous spraying increases. It was found that the reason for this is the formation of powder deposits on the walls of the spray chamber and the increase in its temperature. Using the method of mathematical modelling, the maximum permissible temperature of the walls of the spraying chamber was determined, ways of stabilizing the quality of the powder during industrial production were shown.

Research in the field of analysis of the soft dosage form «Metroterbinazol» used in medical practice

2020 ◽  
Vol 21 (3) ◽  
pp. 32-36
Author(s):  
A. I. Zamaraeva ◽  
◽  
N. S. Bessonova ◽  
T. A. Kobeleva ◽  
A. I. Sichko ◽  
...  
Keyword(s):  
Dosage Form ◽  
Electronic Absorption Spectra ◽  
Spectrophotometric Analysis ◽  
Ethanol Solution ◽  
Ultraviolet Region ◽  
Medicinal Products ◽  
Similar Concentration ◽  
Near Ultraviolet

Aim. Development of a method of analysis of metronidazole and terbinafine in ointment «Metroterbinazol» using spectrophotometry. Materials and methods. A soft dosage form containing 0.1 g of metronidazole, terbinafine and 9.8 g of Tizol gel was used as the object of research. Pharmacopoeia reagents and the method of spectrophotometry were used for experimental work. Measurements were carried out on the SF-2000 spectrophotometer in the near ultraviolet region (λ = 210-340 nm). Results. To achieve this goal, we studied the electronic absorption spectra and optical characteristics of metronidazole and terbinafine in the substance, ethanol solution and in the presence of Tizol gel. The curve of ε (terb) – ε (met) to the wavelength observed a maximum at a wavelength of 223 nm, which corresponds to the maximum of absorption of terbinafine and is close to a less pronounced first absorption maximum of metronidazole (226 nm), also pronounced minimum at a wavelength of 312 nm, which is similar to the second maximum of absorption of metronidazole. The results obtained suggest that the optimal wavelengths are 223 nm and 312 nm. On an artificial mixture with a similar concentration of ingredients according to the prescription, testing was conducted for the analysis of drugs in the joint presence. As a result of experiments, it was found that the mass of metronidazole, found by the Firordt method and the simplified system of equations, is in the limit of 0.0959-0.1053 g, terbinafine – 0.1072-0.1110 g, which corresponds to the permissible deviations. Based on the research, a method for the spectrophotometric analysis of terbinafine and metronidazole in «Metroterbinazole» ointment has been developed that allows quantifying them within the permissible deviations provided for in the regulatory documentation. Conclusion. A method of spectrophotometric quantitative determination of terbinafine and metronidazole is proposed, which allows analyzing medicinal products with a relative error of ± 1.49-1.50% and establishing the quality of manufacturing of «Metroterbinazole» ointment within acceptable standards of deviations.

Evaluation of cut quality of woodfree coated papers

TAPPI Journal ◽  
2013 ◽  
Vol 12 (9) ◽  
pp. 9-15
Author(s):  
BENOÎT DUFOUR, ◽  
WOLFGANG BAUER ◽  
JEAN-FRANCIS BLOCH
Keyword(s):  
Coating Layer ◽  
The State ◽  
Point Of View ◽  
Test Method ◽  
Offset Printing ◽  
Paper Properties ◽  
Coated Papers ◽  
Cut Quality ◽  
Printing Papers

Dusting and blanket pollution are of particular interest in offset printing. Papers must be free of dust and loose particles to drastically reduce the wash interval of the blankets. Those particles are mainly generated during converting operations, such as sheeting. Considering the end-customer point of view, the visual aspect of the cut appears to be very important. To study in detail the influence of the sheeting parameters and paper properties on cut quality, a new test method to quantify the cut quality of woodfree coated papers has been developed. In particular, this method takes into consideration the state of the coating layer near the cutting edges.

Preparation and Photocatalytic Performance of Flower-Shaped Zno/GO/Fe3O4 on Degradation of Rhodamine B

2021 ◽  
Vol 407 ◽  
pp. 161-172
Author(s):  
Mahbboobeh Rezaei ◽  
Ali Shokuhfar ◽  
Nikta Shahcheraghi
Keyword(s):  
Rhodamine B ◽  
Synthesis Method ◽  
Spectrophotometric Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Photodegradation Efficiency ◽  
Time And Being ◽  
Co Precipitation ◽  
Uv C

In this work, a flower-shaped ZnO/GO/Fe3O4 ternary nanocomposite was synthesized via the co-precipitation method. Two significant goals of the study were boosting the degradation efficiency of ZnO and achieving a fast and simple synthesis approach. The structure, properties, and morphology of the product were characterized, and the effect of the ZnO flower-shaped structure in combination with GO nanosheets and magnetite nanoparticles was investigated on the photocatalytic activity. The structure and quality of the prepared nanocomposite were assessed by X-ray diffraction pattern, UV-visible DRS spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM). The catalytic activity of the nanocomposite was assessed by spectrophotometric analysis. The developed nanocomposite offered high photodegradation efficiency in Rhodamine B degradation under UV-C light in comparison with pure ZnO. At a specific period, the efficiency of the synthesized sample was about two times greater than that of pristine ZnO particles. Our nanocomposite is anticipated to have practical benefits in wastewater treatment given its good performance, economic savings through reducing the amount of catalyst consumption and saving time, and being a facile and fast synthesis method.

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