Artículos de revistas sobre el tema "Powder in suspension"
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1
Zhou, Hai Fang, Xiao Xiang Wang y Ri Zhi Wang. "Electrophoretic Deposition of Nacre Coatings on Titanium Substrates". Key Engineering Materials 309-311 (mayo de 2006): 747–50. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.747.
Resumen
Nacre powder suspensions in alcohol added with acetic acid (Suspension I) or calcium chloride (Suspension II) were prepared. Titanium substrates were coated with nacre powder by EPD in the suspensions. The result shows that Suspension II is more stable than Suspension I, and deposition rate in Suspension II is much higher than that in Suspension I. XRD and FTIR results show that the nacre coatings exhibit the same characteristics as the raw nacre powder. SEM morphologies show that uniform coatings are achieved. Scratch test shows that bonding strength of coatings from Suspension I is much higher than that of Suspension II. The higher bonding strength from Suspension I was confirmed to be closely related to the concurrent deposition of organic molecules dissolved in the suspension.
2
Ahmed, Yasser, Emad Ewais y Said El-Sheikh. "Effect of dispersion parameters on the consolidation of starch-loaded hydroxyapatite slurry". Processing and Application of Ceramics 8, n.º 3 (2014): 127–35. http://dx.doi.org/10.2298/pac1403127a.
Resumen
The influence of some parameters controlling the hydroxyapatite (HA) suspension rheology in terms of heat treatment of the HA powder prior to suspension preparation, suspension solid loading and the amount of corn starch addition was thoroughly investigated. The heat treatment of powder at 1100?C prior to suspension preparation was found to be extremely efficient in preparing suspensions with high solid loading of 59 vol.%. In contrast, the highest solid loading that could be developed from the non-heat treated powder was 14 vol.%. This phenomenon is consequence of the changes in the physical and chemical properties of the powder after the heat treatment step. The amount of native corn starch addition has ranged from 10 to 40 vol.%. The addition of corn starch leads to the high retardation in the suspension viscosity, particularly at low shear rate. On the contrary, at higher shear rate the situation is completely different. The properties of the consolidated green sample (produced from suspensions containing various corn starch amounts) in terms of relative density and compressive strength were studied. The results indicated that even though there were no considerable changes in the relative density, the compressive strength was sharply increased with increasing starch amount content until it reached a maximum at 30 vol.% and then decreased thereafter.
3
Bhandare, P. S. y A. V. Yadav. "A REVIEW ON “DRY SYRUPS FOR PAEDIATRICS”". International Journal of Current Pharmaceutical Research 9, n.º 1 (31 de diciembre de 2016): 25. http://dx.doi.org/10.22159/ijcpr.2017v9i1.16789.
Resumen
Suspensions may be defined as preparations containing finely divided drug particles (the suspensoid) distributed somewhat uniformly throughout a vehicle with or without stabilizers and other additives in which drug exhibits a minimum degree of solubility hence conventional oral suspension can be administered immediately (ready to use form) and not requiring reconstitution at the time of dispensing are simply designated as “Oral Suspension”.There is an important category of suspension that are available as dry powders intended for suspension in liquid vehicles. These are dry mixtures containing the drug and suitable suspending and dispersing agents to be diluted and agitated with a specific quantity of vehicle, most often purified water. Drugs that are instable if maintained for extended periods in the presence of aqueous vehicle (eg., many antibiotic drugs) are frequently supplied as dry powder mixtures for reconstitution at the time of dispensing. This type of preparation is designated in the USP by a title “for Oral Suspension”. The reconstituted system is the formulation of choice when the drug stability is a major concern. After reconstitution, these systems have a short but acceptable life if stored at refrigerator temperatures. Reconstitutable oral systems show the adequate chemical stability of the drug during shelf life, avoids the physical stability problems related to solubility, pH and incompatibilities with other ingredients and also reduce the weight of the final product because the aqueous vehicle is absent and consequently the transportation expenses may be reduced.Dry syrup form of the drug is also useful in case of bioavailability as it has high bioavailability rather than tablets and capsules as it disintegrates in water outside of the oral cavity and directly the suspension is gone through the gastrointestinal tract. So the suspension easily absorbs in the GIT.A number of commercial and official preparations are available as dry powder mixtures. The present review gives an account of the excipients used, methods of preparation of dry syrups along with their evaluations, their packaging, examples of research articles, few marketed preparations.
4
Muchtar, Andanastuti, Norazmira Wati y Nor Azri Jaafar. "Deagglomeration of High Purity Fine Alumina Powder via pH Control". ASEAN Journal of Chemical Engineering 2, n.º 1 (20 de octubre de 2008): 55. http://dx.doi.org/10.22146/ajche.50803.
Resumen
This paper presents results from a study on the effect of the pH of suspensions on the deagglomeration of a high-purity (99.99%), fine-grained alumina powder. The pH of the suspension was varied between pH 2 and 3. It is the aim of the study to determine the best pH for a successful dispersion of the alumina powders in the suspension. A series of rheological studies and analytical work under Scanning Electron Microscopy were conducted. It was found that the best pH was pH 2. Data obtained from rheological studies using a viscometer showed that the alumina suspension prepared at pH 2 was least viscous, which may be taken as a negative indicator of the presence of agglomerates. This hypothesis is validated by visual inspection using SEM. For the pH 2 samples, a successful removal of the agglomerates in the green compact has encouraged the sinterability of the samples and thus, resulted in an earlier sintering process at a low-firing temperature. In addition, the sintering characteristics and microstructures of the samples prepared with a pH 2 suspension are also presented.
5
Kai Jian, Ding. "Ultraprecise weight feed at batching of nanopowder materials". Interactive science, n.º 9 (85) (30 de noviembre de 2023): 70–72. http://dx.doi.org/10.21661/r-560327.
Resumen
In the article the current ways and the equipment for batching of powder шmaterials are considered. On the basis of an estimation of volume feeders accuracy authors revealed a necessity of use instead of them weight feeders: vibratory feeders or feeders of a suspension of powders in gas. There is perspective to use of feeders of suspensions of powders in gases for batching of ultra tiny portions of powders.
6
Hodgson, Daniel J. M., Michiel Hermes, Elena Blanco y Wilson C. K. Poon. "Granulation and suspension rheology: A unified treatment". Journal of Rheology 66, n.º 5 (septiembre de 2022): 853–58. http://dx.doi.org/10.1122/8.0000515.
Resumen
Mixing a small amount of liquid into a powder can give rise to dry-looking granules; increasing the amount of liquid eventually produces a flowing suspension. We perform experiments on these phenomena using Spheriglass, an industrially realistic model powder. Drawing on recent advances in understanding friction-induced shear thickening and jamming in suspensions, we offer a unified description of granulation and suspension rheology. A “liquid incorporation phase diagram” explains the existence of permanent and transient granules and the increase of granule size with liquid content. Our results point to rheology-based design principles for industrial granulation.
7
&NA;. "Omeprazole/Antacid-Powder Suspension ??? Santarus". Drugs in R & D 5, n.º 4 (2004): 234–35. http://dx.doi.org/10.2165/00126839-200405040-00010.
8
&NA;. "Omeprazole/Antacid-Powder Suspension ??? Santarus". Drugs in R & D 5, n.º 6 (2004): 349–50. http://dx.doi.org/10.2165/00126839-200405060-00007.
9
Kobayashi, Motoyoshi, Takuya Sugimoto, Shunsuke Sato y Ryouichi Ishibashi. "Climbing Colloidal Suspension". Liquids 3, n.º 1 (2 de enero de 2023): 40–47. http://dx.doi.org/10.3390/liquids3010004.
Resumen
Mixtures of powder and liquid are ubiquitous in nature as well as industries and exhibit complex flowing and deforming behaviors, including sol to gel transition under shear stress. In order to better understand the characteristic features of this type of mixture, we observed the behavior of a mixture of colloidal silica particles and water as a model system under vibration. The mixture showed different states, from powder-like to viscous fluid-like, with increasing content of water. At certain concentrations of silica particles (around 70 wt. %) and under relatively faster vibration (over 17 Hz), we observed that the colloidal suspension of silica particles and water climbed up the wall of a container against gravity. The main purpose of this paper is to report how we can observe the climbing suspension of colloidal silica. The rheological measurements of the climbing suspension demonstrated that the climbing suspension showed shear-thickening behavior, where force chain networks and normal stress differences are considered to develop. Therefore, we speculate that the transient formation and breaking of force networks and normal stress differences under vibration contribute to the occurrence of the climbing suspension. The tunable nature of colloidal suspensions may help to elucidate the climbing mechanism in the future.
10
Van der Biest, Omer, L. Vandeperre, Stijn Put, Guy Anné y Jef Vleugels. "Laminated and Functionally Graded Ceramics by Electrophoretic Deposition". Key Engineering Materials 333 (marzo de 2007): 49–58. http://dx.doi.org/10.4028/www.scientific.net/kem.333.49.
Resumen
Electrophoresis is the effect that when an electric field is applied to a suspension of a powder in a liquid, the powder particles move under influence of this field. Frequently the powder particles also deposit at one of the electrodes. The form of the electrode determines the form of the deposit, hence shaping is possible. The current insights into the science and technology of electrophoretic deposition (EPD) will be summarized. EPD is well suited for shaping layered microstructures (laminates), by simply changing repeatedly between two or more suspensions during deposition. Tubular laminates consisting of silicon carbide layers and crack deflecting graphite interlayers have been produced. These tubes demonstrate an enhanced fracture energy and a gradual mode of failure. Another area of advanced ceramics where the use of EPD makes sense are functionally graded materials (FGM) in which one tries to combine in one component high hardness and high toughness. EPD allows the formation of FGM by depositing from a powder suspension to which a second suspension is continuously added during the process. An example will be shown of a graded WC-Co hardmetal.
11
Van der Biest, Omer, L. Vandeperre, Stijn Put, Guy Anné y Jef Vleugels. "Laminated and Functionally Graded Ceramics by Electrophoretic Deposition". Advances in Science and Technology 45 (octubre de 2006): 1075–84. http://dx.doi.org/10.4028/www.scientific.net/ast.45.1075.
Resumen
Electrophoresis is the effect that when an electric field is applied to a suspension of a powder in a liquid, the powder particles move under influence of this field. Frequently the powder particles also deposit at one of the electrodes. The form of the electrode determines the form of the deposit, hence shaping is possible. The current insights into the science and technology of electrophoretic deposition (EPD) will be summarized. EPD is well suited for shaping layered microstructures (laminates), by simply changing repeatedly between two or more suspensions during deposition. Tubular laminates consisting of silicon carbide layers and crack deflecting graphite interlayers have been produced. These tubes demonstrate an enhanced fracture energy and a gradual mode of failure. Another area of advanced ceramics where the use of EPD makes sense are functionally graded materials (FGM) in which one tries to combine in one component high hardness and high toughness. EPD allows the formation of FGM by depositing from a powder suspension to which a second suspension is continuously added during the process. An example will be shown of a graded WC-Co hardmetal.
12
Bubela, A. I. y K. Yu Babak. "Influence of various factors on sensitivity of magnetic powder control". Glavnyj mekhanik (Chief Mechanic), n.º 1 (2022): 8–14. http://dx.doi.org/10.33920/pro-2-2201-01.
Resumen
The magnetic powder method occupies one of the leading positions in the system of non-destructive quality control of materials. Approximately 80% of the controlled ferromagnetic products are controlled by the magnetic powder control method. The high sensitivity of the control method, its versatility, relatively low labor intensity of control, and the visibility of the results ensured that the method was widely used in industry. The main factors, characteristics and parameters of magnetic powder suspensions affecting the sensitivity of magnetic powder control are considered. A comparative analysis of the sensitivity of experimental suspensions in terms of the effectiveness of detecting artificial surface and subsurface defects of the MO-1 control sample was carried out. The qualitative efficacy of magnetic powders of the "Diagma" and "Crocus" type as a basis for the manufacture of the suspensions is clearly demonstrated, and the effect of autocoagulation on the sensitivity and reliability of the results of magnetic powder control is shown on the example of "Diagma-1100" and "Diagma-1200" powders. The verification of the effectiveness of the suspensions based on ferromagnetic particles γ-Fe₂O₃ and Fe₃O₄ in suspended state did not show their qualitative advantages in comparison with the other experimental suspensions. The further direction of the development of this work is to check the operability of experimental magnetic suspensions γ-Fe₂O₃ and Fe₃O₄ that are not in a suspended state. It is suggested that this state of magnetic suspensions γ-Fe₂O₃ and Fe₃O₄ negatively affects the attraction of magnetic particles by inhomogeneous magnetic fields, and also does not allow a clear indication pattern to form over the defects. In addition, the task of selecting the optimal concentration of magnetic particles in the finished magnetic suspension, in which a high degree of sensitivity to defects will be achieved with the minimum possible consumption of materials included in the magnetic suspension, can be considered as the next stage of the research. English version of the article is available at URL: https://panor.ru/articles/influence-of-various-factors-on-the-sensitivity-of-magnetic-particle-inspection/77764.html
13
Mantry, Shubhrajit, Shubham Shinde, Sahil Shaikh, Sumit Joshi y Ganesh Dama. "Emerging Implementation of Nano-Suspension Technology for Delivery of Poorly Soluble Drug for the Treatment of Helminths Disease". International Journal of Current Research and Review 14, n.º 06 (2022): 43–50. http://dx.doi.org/10.31782/ijcrr.2022.14607.
Resumen
Anthelmintics are medications that are used to treat parasitic worm infections. This comprises flat worms like flukes and tapeworms as well as round worms like nematodes. They are critical for human tropical medicine. Nano-suspensions are one of the many applications of nanotechnology. Nano-suspensions are liquid formulations that feature submicron colloidal dispersion of pharmaceutical active component particles stabilised by surfactants. Nano-suspension technology is a novel and cost-effective method for improving the bioavailability of hydrophobic medicines, particularly those that are poorly soluble in aqueous solutions. Nano-suspensions play a significant role in the development of new medication formulations. High pressure homogenizers, emulsion solvent evaporation, melt emulsification technique, and nanoprecipitation are all used to make nano-suspensions. Particle size, zeta potential, drug content, and in vitro drug dissolution were all examined for the nano-suspensions. Poorly soluble drugs can benefit from nano-suspension technology to improve their stability and bioavailability. The bioavailability of nano-suspension was also tested in mice, which showed that the particle size distribution of nano-suspension was considerably affected by bioavailability. The rate of anthelmintic nano-suspension dissolution was substantially higher than that of raw drug powder. In vivo pharmacokinetic characteristics of nano-suspension indicated a substantial increase in Cmax and AUC(0-t) when compared to pure drug. When compared to pure drug bioavailability, anthelmintic nano-suspension had a greater oral bioavailability.
14
Moiseeva, K. M. "COMBUSTION OF ALUMINUM POWDER-AIR SUSPENSION IN A SWIRL FLOW". Eurasian Physical Technical Journal 18, n.º 2 (11 de junio de 2021): 47–55. http://dx.doi.org/10.31489/2021no2/47-55.
Resumen
The article is devoted to the numerical solution of the problem of the combustion of powder metal fuel in a combustion chamber with swirling flow. A physico-mathematical model of the flow of an air suspension of aluminum powder in a swirling flow in a cylindrical combustion chamber with a sudden expansion is presented. The physical and mathematical formulation of the problem is based on the approaches of the mechanics of two-phase reacting media. The solution was carried out using the arbitrary discontinuity decay method. The results of a numerical parametric study of the features of the combustion of an air suspension of aluminum powder depending on its composition, the axial flow rate of the mixture at the entrance to the combustion chamber, and the value of the swirl speed are shown.
15
Stobierski, Ludosław, Jerzy Lis y Agnieszka Gubernat. "SiC Powder for Casting from Aqueous Suspension". Advances in Science and Technology 45 (octubre de 2006): 297–302. http://dx.doi.org/10.4028/www.scientific.net/ast.45.297.
Resumen
The activation of silicon carbide by boron and carbon is required to obtain dense monophase sintered body from SiC powder. The presence of carbon renders casting from aqueous suspension impossible. The SiC powders with boron and extra carbon were prepared by combustion method (SHS), where carbon was bound to SiC particles in a stable way. The experiments showed that this powder could be used for processing by casting of aqueous suspension. Finally nearly dense polycrystals were obtained by pressureless sintering.
16
Zhang, Hai Long, Jun Li, Guo Hong Zhou y Shi Wei Wang. "Fabrication of Aluminium Nitride by Electrophoretic Deposition". Advanced Materials Research 412 (noviembre de 2011): 183–86. http://dx.doi.org/10.4028/www.scientific.net/amr.412.183.
Resumen
The electrophoretic deposition (EPD) technique has been developed to prepare AlN ceramics and the topic of this paper was the investigation of the AlN ceramic suspensions for electrophoretic deposition. The only addition of triethylamine didn’t promote the hydrolysis of AlN powder in 95% ethanol. The absorption of the polyacrylic acid (PAA) resulted in an increased Zeta potential, indicating that PAA is a very effective dispersant for the AlN and Y2O3 powders. Furthermore, by adding a combination of PAA and triethylamine, an stable AlN suspension could be obtained which was necessary for realising a high packing density in the electrophoretically deposited green bodies. The conductivity measurements indicated that suspension conductivity was lower than liquid conductivity. The lower conductivities of the suspensions could be explained by the fact that in concentrated suspensions the free ionic species are hindered in their movement by the particles. The conductivity of the centrifugate was higher than that of the suspension. It can be concluded that during the EPD the current in the suspension is mainly carried by the free ionic species. The transport of positively charged ionic species to the upper electrode (cathode) was slower than their consumption by the electrode reaction, an increased concentration overvoltage caused a significant increase in total electrical resistance due to the higher potential drop at the cathode. Finally, the EPD was usually stopped according to the increase in potential drop.
17
Tarasi, Fariba, Elnaz Alebrahim, Ali Dolatabadi y Christian Moreau. "A Comparative Study of YSZ Suspensions and Coatings". Coatings 9, n.º 3 (13 de marzo de 2019): 188. http://dx.doi.org/10.3390/coatings9030188.
Resumen
The demand for suspensions that are used in thermal spray processes is expanding from research labs using the lab-prepared suspensions toward actual coating production in different industrial sectors. Industrial applications dictate the reduced production time and effort, which may in turn justify the development of the market for ready-to-use commercial suspensions. To this end, some of the powder suppliers have already taken steps forward by introducing, to the market, suspensions of some of the most used materials, such as yttria-stabilized zirconia (YSZ), alumina, and titania. However, there is a need to compare the suspension characteristics over time and the resultant coatings when using these suspensions when compared with the freshly prepared homemade suspensions. In this work, such a comparison is done using YSZ suspensions of the sub-micron to a few micron powders. In addition, some changes in the suspensions’ formula were performed as a tool to vary the coatings’ microstructures in a more predictable way, without any variation of the spray parameters. The coatings were generated while using both radial and axial injection of the suspensions into Oerlikon-Metco 3MB and Mettech Axial III plasma spray torches, respectively. A clear effect of suspension viscosity on the coating microstructure was observed using the 3MB torch with a radial injection of suspension (i.e., cross flow atomization). However, the viscosity role was not dominant when using the Axial III torch with an axial feed injection system (i.e., coaxial flow atomization).
18
Lazic, Marija, Kornelija Simovic, Vesna Miskovic-Stankovic, Predrag Jovanic y Dusan Kicevic. "The influence of the deposition parameters on the porosity of thin alumina films on steel". Journal of the Serbian Chemical Society 69, n.º 3 (2004): 239–49. http://dx.doi.org/10.2298/jsc0403239l.
Resumen
The influence of the deposition parameters on the porosity of thin alumina films electrophoretically deposited on steel from aqueous suspensions was investigated. The effects of the applied voltage, deposition time, suspension temperature and the solid content of the aqueous suspension on the porosity of the obtained alumina films have been determined using optical microscopy coupled with image analysis. It was shown that the lowest film porosity was obtained from a suspension containing 20 wt.% alumina powder at the lowest applied voltage (30 V), for a longer deposition time (10 min) using a suspension temperature of 30 ?C. This behavior can be explained by the smaller amount of hydrogen evolved on the cathode during the electrophoretic deposition process.
19
Alayo, Mutiat A., Oluyemisi A. Bamiro, Shittu Esther, Lateef G. Bakre y Olutayo A. Adeleye. "Evaluation of Basella alba L. Mucilage as a Suspending Agent in Metronidazole Suspension". Jordan Journal of Pharmaceutical Sciences 15, n.º 3 (1 de septiembre de 2022): 428–37. http://dx.doi.org/10.35516/jjps.v15i3.418.
Resumen
In the quest for natural biodegradable, non-toxic polymers for use as excipients in pharmaceutical formulations, mucilage of Basella alba L (BAM) stem was isolated and evaluated as a suspending agent in metronidazole suspensions at different concentrations (0.5% - 2% w/v) in comparison to tragacanth (TCG) and gelatin gums (GLT). The micromeritic properties of the mucilage powder were determined and the metronidazole suspension was characterized using flow rate, redispersion number, sedimentation volume, viscosity and pH. The degree of flocculation was also determined. BAM powder has good flow property with minimal swelling. The order of flow rate of metronidazole suspension was BAM=TCG>GLT while sedimentation volume ranking was TCG>BAM>GLT. There was no significant difference (p>0.05) in the redispersion number of BAM and TCG formulations. The viscosities of formulations containing BAM and TCG at concentrations of 0.5%-1.0% w/v were the same. The pH of the suspensions ranged from 5 to 8. The degree of flocculation was in the order GLT>BAM>TCG. From our findings, BAM can be used as an alternative suspending agent in suspension formulation.
20
Ming, Quan Yan y Liu You He. "Powder-suspension dielectric fluid for EDM". Journal of Materials Processing Technology 52, n.º 1 (mayo de 1995): 44–54. http://dx.doi.org/10.1016/0924-0136(94)01442-4.
21
Bekers, M., M. Bekers, M. Grube, D. Upite, E. Kaminska, R. Linde, R. Scherbaka y A. Danilevich. "Carbohydrates in Jerusalem artichoke powder suspension". Nutrition & Food Science 37, n.º 1 (13 de febrero de 2007): 42–49. http://dx.doi.org/10.1108/00346650710726940.
22
Shi, Shenglong, Jinsheng Sun, Kaihe Lv, Jingping Liu, Yingrui Bai, Jintang Wang, Xianbin Huang, Jiafeng Jin y Jian Li. "Comparative Studies on Thickeners as Hydraulic Fracturing Fluids: Suspension versus Powder". Gels 8, n.º 11 (8 de noviembre de 2022): 722. http://dx.doi.org/10.3390/gels8110722.
Resumen
To overcome the problems of long dissolution time and high investment in surface facilities of powder thickeners in hydraulic fracturing, a novel suspension of a thickener as a fracturing fluid was prepared using powder polyacrylamide, nano-silica, and polyethylene glycol by high-speed mixing. The suspension and powder were compared in terms of properties of solubility, rheological behavior, sand carrying, drag reduction, and gel breaking. The results showed that the suspension could be quickly diluted in brine within 5 min, whereas the dissolution time of powder was 120 min. The suspension exhibited better performance in salt resistance, temperature resistance, shear resistance, viscoelasticity, sand carrying, and drag reduction than powder. The powder solution was broken more easily and had a lower viscosity than suspension diluent. These improvements in properties of the suspension were due to the dispersion of nano-silica in the polymer matrix; the mobility of thickener chains was inhibited by the steric hindrance of the nano-silica. Nano-silica particles acted as crosslinkers by attaching thickener chains, which strengthened the network structure of the thickener solution. The presence of hydrogen bonds between the thickener matrix and the nano-silica restricted the local movement of thickener chains, leading to a stronger spatial network. Therefore, this novel suspension showed good potential for fracturing applications.
23
H. Jaber, Saba, Zainab T.Salih y Hiba M. Salmo. "Formulation of Azithromycin Suspension as an Oral Dosage Form". Iraqi Journal of Pharmaceutical Sciences ( P-ISSN 1683 - 3597 E-ISSN 2521 - 3512) 21, n.º 1 (28 de marzo de 2017): 61–69. http://dx.doi.org/10.31351/vol21iss1pp61-69.
Resumen
Azithromycin is the drug of choice in the treatment of several bacterial infections, most often those causing middle ear infection, bronchitis, pneumonia, typhoid and sinusitis. It’s also effective against certain urinary tract infections and venereal diseases. This study was carried out to prepare an acceptable suspension either as dry physical mixture powder or granules to be reconstituted, through studying the effect of various type and concentration of suspending agent (xanthan gum, hydroxypropyl methylcellulose (HPMC), either alone or in combination) on the release profile of the drug. The best prepared suspension formulas (H& III) were selected depending on the dissolution profile of each formulas and then compared with the reference suspensions (Zithromax and Azi-once).The viscosity, sedimentation volume, Resuspendability and expiration date were evaluated for the chosen formulas (H&III) and compared with references ZithromaxÒ and Azi-onceÒ.The result indicated that the chosen formula – H had better dissolution rate compared with references suspensions, Also it was less viscous than them.While other chosen formula – III had lower dissolution rate compared with ZithromaxÒ and higher dissolution rate than AZi – once, also it was less viscous than both references.It was found that the dry physically mixed powder (formula – H) was more stable than the granular suspension (Formula III) since the expiration date for formula H and formula III were 3.24 and 2.7 years respectively.
Key words: Azithromycin, suspending agent, suspension.
24
Hayashi, Shigeo y Zenbe-e. Nakagawa. "Electrophoretic Deposition of Different Yttria-Stabilized Zirconia Powder on Stainless Steel and Carbon Electrodes". Key Engineering Materials 314 (julio de 2006): 75–80. http://dx.doi.org/10.4028/www.scientific.net/kem.314.75.
Resumen
Stabilized zirconia is a common material for oxygen sensors as a solid electrolyte. The electrophoretic deposition (EPD) behavior of 8Y-YSZ (Yttria-stabilized zirconia with 8 mol% Y2O3) powder was investigated on stainless steel and carbon based substrates. This study will be the starting point for the fabrication of complex shaped (even in micro-scale) YSZ based devices. Ethanol + HNO3 based suspensions were used for the EPD experiments and three different YSZ powders were deposited, one commercially available powder and two own-made coprecipitated powder. The latter powders were calcined at respectively 900 and 1200°C. The concentration of the suspension was 3 g/300 cm3, and a small amount of HNO3 solution was added as a dispersant. DC electric field of 100-200 V/15 mm was applied between parallel electrodes. It was found that on stainless steel electrodes the calcined own-made coprecipitated powder showed the best best deposition properties, whereas the commercial YSZ powder showed the best deposition properties on carbon electrodes. These experimental results are discussed with regard to some powder properties (e.g. particle size distribution and packing behavior) and the adhesion between the particles and the substrate.
25
Bays, Harold, Kevin Maki y Kathy Schmitz. "Colesevelam Hydrochloride Powder for Oral Suspension Versus Cholestyramine Powder for Oral Suspension: Comparison of Acceptability and Tolerability". Endocrine Practice 17, n.º 2 (marzo de 2011): 218–25. http://dx.doi.org/10.4158/ep10251.or.
26
Fukada, Yoko y Patrick S. Nicholson. "Instability of Si3N4/, SiC/, and MoSi2/ethanol suspensions". Journal of Materials Research 18, n.º 1 (enero de 2003): 45–52. http://dx.doi.org/10.1557/jmr.2003.0007.
Resumen
Time-dependent suspension behavior is reported for nonoxide ceramic powders (Si3N4, SiC, and MoSi2) in ethanol. The suspension pH (and therefore the stability) changed with time. X-ray photoelectron spectroscopy, inert gas fusion, inductively coupled plasma, and high-resolution transmission electron microscopy were used to track changes of surface chemistry. The adsorption of the base, tetramethyl ammonium hydroxide (TMAH), is examined. The pH drop on powder addition to pure EtOH was used to gain insight into the role of TMAH coverage of the powder surfaces.
27
S, Pavithra, Prabavathi C, S. Gomathi, C. Gowri, B. Senthilnathan, Selvanayagi S, Jayashree S, Parameshwari M y Karthikeyan G. "Design and Development of Cefpodoxime Proxetil Dry Suspension Using Fenugreek Powder as Natural Suspending Agent". EAS Journal of Pharmacy and Pharmacology 6, n.º 01 (17 de enero de 2024): 1–15. http://dx.doi.org/10.36349/easjpp.2024.v06i01.001.
Resumen
Dry suspension refers to commercial dry solutions that must be dispensed with water. The bitter taste has had a significant impact on the development of oral preparations and therapeutic uses for numerous toxic medicines. The majority of patients want to take effective treatments that taste good and are easy to administer. It is also defined as an intimate mixture of dry, finely split medication and excipients that, when mixed with an appropriate vehicle, produces a suspension. Reconstitutable suspension is reconstituted at the time of use and can thus be used as a liquid formulation, avoiding swallowing issues. When drug stability is a critical concern, the reconstituted system is the formulation of choice. A variety of commercial and government remedies are available as dry powder combinations or granules that are meant to be suspended in water or another vehicle before being taken orally. The current study attempted to compare assessment criteria by employing three natural gums as a suspending agent in a cefpodoxime proxetil oral dry suspensions: acacia, Trigonella foenum graecum (Family: Leguminosae) seeds, also known as fenugreek seeds, and xanthan gum.
28
Shang, Hong Fei. "Preparation of Suspended Liquid Hardener for No-Bake Phosphate Binder Sand". Advanced Materials Research 148-149 (octubre de 2010): 338–41. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.338.
Resumen
In order to solve the problem that powder hardeners for no-bake phosphate binder sand cause powder pollution, preparation of suspended liquid hardener has been studied in this paper. Orthogonal array L9(34) was selected to arrange the experiment. Under every factor and level an experiment was done, and suspension rate after four hours of the suspended liquid hardener was taken as experimental target. Results show that the addition of suspension agent and interaction between vector and suspension agent are significant factors at significance level α = 0.05. The best scheme is the one which contents 500g powder magnesia, 500g industrial alcohol vector and 20g SN suspension agent.
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Krupskaya, T. V., V. M. Gun’ko, L. S. Andriyko, N. V. Yelahina y V. V. Turov. "Water Clusterization in the Interparticle Space of Hydrophobic Nanosilica АМ-1". Physics and Chemistry of Solid State 22, n.º 1 (26 de enero de 2021): 24–30. http://dx.doi.org/10.15330/pcss.22.1.24-30.
Resumen
The processes occurring in hydrated powders and concentrated suspensions of hydrophobic silica were studied by 1H NMR spectroscopy. It is shown that a mixture of methyl silica and water with a hydration of less than 1 g / g is a wet powder, where water is in the form of submicron clusters filling the interparticle voids of nanosilica, and the interfacial energy is directly proportional to the amount of added water. It was found that at high water concentrations there is a spontaneous increase in the size of water structures, which is accompanied by a sharp decrease in interfacial energy, that may reflect the disappearance of narrow interparticle voids or their filling with air. It is shown that aqueous suspensions of AM-1 are easily mixed with a weakly polar organic solvent chloroform, forming a stable suspension with close the amounts both of water and chloroform. It was revealed that the aqueous suspension of methyl silica has high thixotropic properties, which depend on the time and the magnitude of the applied mechanical loads.
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AOKI, Takashi, Chiaki ISHII, Ken'ichi KOSEKI y Takeshi AMARI. "Nonlinear Rheological Properties of Metal Powder Suspension". Journal of the Japan Society of Colour Material 71, n.º 9 (1998): 548–54. http://dx.doi.org/10.4011/shikizai1937.71.548.
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Li, Dan, Zhou Lan Yin y Qi Yuan Chen. "Study on Influence of Polyethylene Glycol on Dispersion of Pyrite Powder in Aqueous Solution". Advanced Materials Research 554-556 (julio de 2012): 349–52. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.349.
Resumen
The influences of three kinds of polyethylene glycol (PEG), namely PEG-200, PEG-1000 and PEG-20000, on the dispersion stability of pyrite powder in aqueous solution were investigated by spectrophotometry. The results indicated that the stability of pyrite powder dispersed in aqueous solution was remarkably dependent upon the molecular weight and content of PEG, pH value of suspension, and ultrasonication power. Among three kinds of polyethylene glycol, PEG-20000 was the most effective additive to improve the dispersion stability and wettability of pyrite powder in water. When 8% PEG-20000 was employed as the dispersant, the best dispersion stability of pyrite powder in aqueous solution could be obtained under the conditions of pH at 5-6 and 100-W ultrasonication power. The FTIR spectroscopic analysis showed that the adsorption between the polyethylene glycol and pyrite ore powder was formed by hydrogen bonding. The adsorption of polyethylene glycol onto the surface of pyrite powder via hydrogen bonding provided a high degree of steric stabilization, which effectively prohibited the aggregation of pyrite powder, and thus the dispersion stability of as-formed aqueous suspension was promoted.
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Prabhakaran, K., E. M. Jayasingh, S. Raghunath, C. Durgaprasad y S. C. Sharma. "Aqueous dispersion characteristics of PMN-PT powder prepared by partial oxalate route". Advances in Applied Ceramics: Structural, Functional and Bioceramics 108, n.º 3 (abril de 2009): 145–48. http://dx.doi.org/10.1179/174367613x13789812363902.
Resumen
Aqueous dispersion of PMN-PT powder prepared by partial oxalate process has been studied using ammonium poly(acrylate) dispersant. Parameters such as dispersant concentration and pH to achieve well dispersed suspensions have been determined by measurement of viscosity and gravitational sediment density. Suspension with PMN-PT powder loading in the range of 50 to 58 vol.-% showed very low viscosity in the range of 0·125–0·325 Pa s at a shear rate of 93 s−1. The suspensions are shear thinning and obey Casson model. PMN-PT powder suspensions of solids loading in the range of 50 to 58 vol.-% showed yield stress in the range of 0·625 to 9·5 Pa respectively. The green body prepared by casting the suspensions in an open mould followed by drying in air showed high density (63·4% TD) and narrow pore size distribution with a median pore size of 0·14 μm.
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Vertanessian, Alejandro, Andrew Allen y Merrilea J. Mayo. "Agglomerate formation during drying". Journal of Materials Research 18, n.º 2 (febrero de 2003): 495–506. http://dx.doi.org/10.1557/jmr.2003.0063.
Resumen
The evolution of agglomerate structure during drying of particles from suspension has been studied for a nanocrystalline Y2O3 (8% mol fraction)-stabilized ZrO2 powder. Agglomerates in drying and dried suspensions were examined at the smallest size scales (1 nm to 1 μm) using ultra-small angle x-ray scattering (USAXS) and at the largest size scales (100 nm to 10 μm) using scanning electron microscopy. The results were correlated with the degree of particle dissolution in each suspension (measured by flame absorption spectroscopy of the suspension filtrate) and the zeta potential of the particles in suspension prior to drying. Results show that large agglomerates readily form across a pH range from 2 to 9. The fact that Y+3 ion dissolution varies by over four orders of magnitude in this range leads to the conclusion that there is little direct correlation between the degree of Y dissolution and agglomeration in this system (Zr ion dissolution was below the detection limit at all pH values studied). The observation of large agglomerates well before the introduction of air-water interfaces into the drying mass likewise leads to the conclusion that capillary forces are not essential to agglomerate formation. Instead, agglomerates appear to form as a direct consequence of increasing suspension concentration. Zeta potential also plays a role. Specifically, there was a notable change in agglomerate morphology as the isoelectric point was approached, at approximately pH 8. Here USAXS shows the particles in suspension to have a layered interior structure, with small primary particles aggregated in sheets to form each blocky particle. This is in contrast to the more rounded agglomerates formed away from the isoelectric point, which appear to be composed of the same primary particles arranged in chainlike structures. USAXS of powders from the dried suspensions confirms that the structures seen after drying are the same as those present in suspension. The two structural morphologies are attributed to diffusion-limited (sheets) versus reaction-limited (chains) aggregation, respectively.
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Farid, Nurfiddin, Andi Suparlan Isya Syamsu, Ahmad Irsyad Aliah y Anna Muthmainna Murdi. "Uji Efektivitas Anthelmintik Formula Suspensi Biji Mentimun (Cucumissativus L.) Terhadap Cacing Gelang (Ascaris Lumbricoides)". Jurnal Farmasi Galenika (Galenika Journal of Pharmacy) (e-Journal) 6, n.º 1 (2 de marzo de 2020): 104–13. http://dx.doi.org/10.22487/j24428744.2020.v6.i1.14307.
Resumen
The Effectiveness Test of Cucumber Seeds Suspension Formula (Cucumis sativus L) towards Roundworms (Ascaris lumbricoides) as in Vitro Anthelmintic, It has been conducted research to know cucumber seeds powder (Cucumis sativus L) can be made into form of suspension stock and to know stock of cucumber seeds suspension (Cucumis sativus L) can give effect of anthelmintic toward roundwoms Ascaris lumbricoides. The research was conducted by using experimental method. Powder of cucumber seeds (Cucumis sativus L) were made into suspension stock with 3 concentratios such as 5%, 10%, 15% concetrations and suspension without powder of cucumber seeds (Cucumis sativus L) with different addition subtance concentration. Test animal used was roundworm (Ascaris lumbricoides) that was taken by pig’s intestine. Treatment group consisted into five categories such as 125 mg positive control of pamoat pirantel (Combantrin®), negative control of suspension without powder of cucumber seeds (Cucumis sativus L), and category of cucumber seeds suspension (Cucumis sativus.L) as 5%, 10%, and 15%. Each group was soaked with 40 ml test ingredient into petri dish. Then it was observed and writte the number of died worms in every minute. 100% observation of died worm was group of positive control at 405 minutes, negative control at 1710 minutes, 5% concetration of cucumber seeds suspension stock at 540 minutes, 10%concentration at 465 minutes and 15% concentration at 420 minutes. The result of research showed that cucumber seeds (Cucumis sativus L) can be made into suspension stock and effective as anhelmintic toward roundworms Ascaris lumbricoides.
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Hsu, Huang Jan, Shyh Yuan Lee, Shinn Liang Chang y Cho Pei Jiang. "Surface Modification of High Density Ceramic Powder for Increasing Suspension Capacity in Three-Dimensional Printing Application". Materials Science Forum 936 (octubre de 2018): 159–63. http://dx.doi.org/10.4028/www.scientific.net/msf.936.159.
Resumen
Three-dimensional slurry printing is a promising tool for making ceramic object but it limits in high dense ceramic powder because of poor suspension capacity. This study uses zirconia powder with an average diameter of 2 μm because its density is 5.67 g/cm3. A treatment protocol is proposed to improve the suspension capacity of zirconia powder including the ball milling, surface modification and resin blending. Experimental results show that adding 1% of isostearyl titanate, a coupling agent, for surface modification can enhance the lipophilicity of zirconia powder. Mixing surface modification powder in resin with a weight ratio of 7:3 and carrying on ball milling with 100 RPM for 6 hours can obtain the diameter of powder less than 400 nm. As a result, the zirconia slurry can obtain good suspension capacity which is over 48 hours.
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Fabiszak, Maciej. "Wet Powder White – powder suspension applicable not only to the adhesive sides of adhesive tapes". Issues of Forensic Science 304 (2019): 96–122. http://dx.doi.org/10.34836/pk.2019.304.4.
Resumen
The article presents new possibilities of revealing fingerprints on non-absorbent surfaces by using Wet Powder White, known and used in Polish dactyloscopy. Powder suspension based on titanium dioxide has been successfully used to reveal fingerprints on the adhesive sides of non-porous tapes, as well as on the inner surfaces of rubber gloves. So far, however, the broader application of Wet Powder White has not been known in Polish dactyloscopic practice. Foreign publications quoted in the article, research conducted and the use of white suspension powder in dactyloscopic opinions dedicated to the visualization of traces unequivocally confirm the high effectiveness of Wet Powder White in revealing fingerprints on non-absorbent surfaces, especially on plastic packaging and areas that have been or could have been previously wetted or subjected to high humidity.
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Bekem, Aylin y Ahmet Unal. "Polyamide 12/E-glass Fabric Composite Production with Dip-coating". MATEC Web of Conferences 188 (2018): 01022. http://dx.doi.org/10.1051/matecconf/201818801022.
Resumen
In this study PA12 was reinforced with E-glass woven fabric by dip-coating. PA12 powder and ethanol suspensions were prepared with ratios at 30, 40 and 50% of powder to obtain different fibre contents. Coated fabrics were laid-up and kept in oven at 60°C to evaporate ethanol. Then it was placed in a compression mould and pressed. Obtained laminates were subjected to tensile, bending and impact tests. Fractured surfaces were observed. It was found that mechanical properties were highest when 40% PA powder used in suspension with dip-coating with additional lamination. Fibre failure and fibre pull-out were observed on fractured surfaces.
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Prihandana, Gunawan Setia, Tutik Sriani, Kei Prihandana, Yuta Prihandana, Muslim Mahardika, Mohd Hamdi Bin Abdul Shukor y Kimiyuki Mitsui. "Study on the Effect of Nano and Micro MoS2 Powder in Micro-Electrical Discharge Machining". Advanced Materials Research 264-265 (junio de 2011): 1450–55. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1450.
Resumen
The application of powder mixed dielectric to improve the efficiency of electrical discharge machining (EDM) has been acknowledged extensively. However, the study of micro-size powder suspension in micro-EDM field is still limited. In this research, nano and micro size powder of MoS2 were used as catalyst agent. Powder suspension in different size was able to provide significant improvement in material removal rate and surface quality to increase the efficiency in μ- EDM processes.
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Frankaer, Christian G., Olga V. Moroz, Johan P. Turkenburg, Stein I. Aspmo, Majbritt Thymark, Esben P. Friis, Kenny Stahl, Jens E. Nielsen, Keith S. Wilson y Pernille Harris. "Analysis of an industrial production suspension ofBacillus lentussubtilisin crystals by powder diffraction: a powerful quality-control tool". Acta Crystallographica Section D Biological Crystallography 70, n.º 4 (21 de marzo de 2014): 1115–23. http://dx.doi.org/10.1107/s1399004714001497.
Resumen
A microcrystalline suspension ofBacillus lentussubtilisin (Savinase) produced during industrial large-scale production was analysed by X-ray powder diffraction (XRPD) and X-ray single-crystal diffraction (MX). XRPD established that the bulk microcrystal sample representative of the entire production suspension corresponded to space groupP212121, with unit-cell parametersa= 47.65,b= 62.43,c= 75.74 Å, equivalent to those for a known orthorhombic crystal form (PDB entry 1ndq). MX using synchrotron beamlines at the Diamond Light Source with beam dimensions of 20 × 20 µm was subsequently used to study the largest crystals present in the suspension, with diffraction data being collected from two single crystals (∼20 × 20 × 60 µm) to resolutions of 1.40 and 1.57 Å, respectively. Both structures also belonged to space groupP212121, but were quite distinct from the dominant form identified by XRPD, with unit-cell parametersa= 53.04,b = 57.55,c= 71.37 Å anda= 52.72,b= 57.13,c= 65.86 Å, respectively, and refined toR= 10.8% andRfree= 15.5% and toR= 14.1% andRfree= 18.0%, respectively. They are also different from any of the forms previously reported in the PDB. A controlled crystallization experiment with a highly purified Savinase sample allowed the growth of single crystals of the form identified by XRPD; their structure was solved and refined to a resolution of 1.17 Å with anRof 9.2% and anRfreeof 11.8%. Thus, there are at least three polymorphs present in the production suspension, albeit with the 1ndq-like microcrystals predominating. It is shown how the two techniques can provide invaluable and complementary information for such a production suspension and it is proposed that XRPD provides an excellent quality-control tool for such suspensions.
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A. Sabri, Lubna, Alaa A. Abdul-Rasool y Muayad A. Shehab. "Formulation of Rifampicin Suspension". Iraqi Journal of Pharmaceutical Sciences ( P-ISSN: 1683 - 3597 , E-ISSN : 2521 - 3512) 15, n.º 2 (31 de marzo de 2017): 1–7. http://dx.doi.org/10.31351/vol15iss2pp1-7.
Resumen
Rifampicin is the drug of choice in treatment of tuberculosis. Also, it is effective in treatment of various bacterial infections.This study was carried out to prepare a stable suspension for rifampicin through preparation of different formulas of rifampicin aqueous suspension either as ready to use or as granular powder to be reconstituted.The selected formula (A) was evaluated and compared with commercial brand of rifampicin (Rifactine®) as a reference through measuring their dissolution rates and other physical properties.The results indicated that the selected formula had better dissolution rate compared with the reference suspension and the rheogram showed that the selected formula was less viscous than the reference one.Also, it was found that the granular rifampicin was more stable than the ready to use suspension, since the expiration date of granular rifampicin was 2.6 years, while the expiration date of ready to use suspension was 1.8 years.
Key words :Rifampicin , Suspending agent ,Powder for reconstitution , Aqueous suspension
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Ali, Ahmed H. y Shaimaa N. Abd-Alhammid. "Enhancement of Solubility and Improvement of Dissolution Rate of Atorvastatin Calcium Prepared as Nanosuspension". Iraqi Journal of Pharmaceutical Sciences ( P-ISSN: 1683 - 3597 , E-ISSN : 2521 - 3512) 28, n.º 2 (22 de diciembre de 2019): 46–57. http://dx.doi.org/10.31351/vol28iss2pp46-57.
Resumen
Atorvastatin have problem of very slightly aqueous solubility (0.1-1 mg/ml). Nano-suspension is used to enhance it’s of solubility and dissolution profile. The aim of this study is to formulate Atorvastatin as a nano-suspension to enhance its solubility due to increased surface area of exposed for dissolution medium, according to Noyes-Whitney equation.
Thirty one formulae were prepared to evaluate the effect of ; Type of polymer, polymer: drug ratio, speed of homogenization, temperature of preparation and inclusion of co-stabilizer in addition to the primary one; using solvent-anti-solvent precipitation method under high power of ultra-sonication. In this study five types of stabilizers (TPGS, PVP K30, HPMC E5, HPMC E15, and Tween80) were used in three different concentrations 1:1, 1:0.75 and 1:0.5 for preparing of formulations. At the same time, tween80 and sodium lauryl sulphate have been added as a co-stabilizer.
Atorvastatin nano-suspensions were evaluated for particle size, PDI, zeta potential, crystal form and surface morphology. Finally, results of particle size analysis revealed reduced nano-particulate size to 81nm for optimized formula F18 with the enhancement of in-vitro dissolution profile up to 90% compared to 44% percentage cumulative release for the reference Atorvastatin calcium powder in 6.8 phosphate buffer media. Furthermore, saturation solubility of freeze dried Nano suspension showed 3.3, 3.8, and 3.7 folds increments in distilled water, 0.1N Hcl and 6.8 phosphate buffers, respectively. Later, freeze dried powder formulated as hard gelatin capsules and evaluated according to the USP specifications of the drug content and the disintegration time.
As a conclusion; formulation of poorly water soluble Atorvastatin calcium as nano suspension significantly improved the dissolution of the drug and enhances its solubility.
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Liu, Ji Yan, Shi Ning Ma, Ji Qiu y Xiang Bo Suo. "Effect of Sodium Dodecylbenzenesulfonate on Dispersion of SiO2 Nano-Powder in Aqueous System". Advanced Materials Research 105-106 (abril de 2010): 808–11. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.808.
Resumen
Good dispersing stability is required for nano-SiO2 which, however, tends easily to conglomerate, to be widely applied as an important functional material of high toughness, high resistance to corrosion and good high-temperature performance. Through ultrasonic treatment, the suspension of SiO2 nano-powder in water was prepared utilizing sodium dodecylbenzenesulfonate (SDBS) as the dispersant. The effect of SDBS content and ultrasonic treatment time on the suspension stability was investigated by way of testing the particle size of SiO2 nano-powder, the Zeta potential and transmittance of the suspension. The results show that with increasing SDBS content, the particle size of SiO2 nano- powder decreases and then increases, which is similar to the case of increasing the ultrasonic treatment time. With optimum SDBS content, the suspension of SiO2 nano-powder possesses a good dispersing stability due to the existence of electrostatic and steric effects resulting from the particular structure of SDBS. The optimum dispersing condition is SDBS of 1.6 wt% with the ultrasonic time of 18 min.
43
Vukšić, Milan, Irena Žmak, Lidija Ćurković y Danko Ćorić. "Effect of Additives on Stability of Alumina—Waste Alumina Suspension for Slip Casting: Optimization Using Box-Behnken Design". Materials 12, n.º 11 (29 de mayo de 2019): 1738. http://dx.doi.org/10.3390/ma12111738.
Resumen
The green machining of alumina (Al2O3) green bodies generates a certain amount of waste alumina powder. Waste alumina ceramic powder should be disposed of as non-hazardous waste in a legally compliant manner. The influence of additives on the stability of 70 wt.% (≈40 vol.%) alumina—waste alumina water-based suspension was investigated in the presented research. A Box-Behnken three-factor response surface design was used for the preparation of stable highly-concentrated suspensions with the addition of three additives. The optimal amount of each additive was selected according to the obtained results of minimal apparent viscosity: 0.05 wt.% Tiron as dispersant, 0.1 wt.% poly (vinyl alcohol) as binder and 0.2 wt.% magnesium aluminate spinel as abnormal grain growth inhibitor. The analysis of variance was used to identify the contribution of each additive. The zeta potential and sedimentations tests were performed to confirm the suspension stability measurements at different pH values. Alumina particles were optimally dispersed at pH values between 8 and 11. According to the results, the investigated composition of 20 wt.% waste alumina powder (weight content, dry alumina powder), with the addition of optimal amounts of additives, shows a possible application in the production of ceramics by slip casting.
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Toma, Filofteia Laura, Ghislaine Bertrand, Cathy Meunier, Sylvie Begin, Didier Klein y Christian Coddet. "Environmental Applications of the Reactive Titania Coatings Elaborated by Suspension Plasma Spraying". Advances in Science and Technology 45 (octubre de 2006): 2182–87. http://dx.doi.org/10.4028/www.scientific.net/ast.45.2182.
Resumen
This paper deals with the elaboration of titanium dioxide coatings, designed for photocatalytic applications, obtained by a non-conventional method of deposition: suspension plasma spraying (SPS). SPS is an alternative of the atmospheric plasma spraying (APS) in which the feedstock material is a suspension of the powder to be sprayed. The method consists in injection and atomization of a slurry (suspension of fine particles in a solvent) in an enthalpic source (plasma). TiO2 P25 powder (Degussa AG) was mechanically dispersed in distilled water and ethanol and injected in Ar-H2 or Ar-H2-He plasma under atmospheric conditions. SEM and XRD were performed to study the microstructure and the crystalline phases of the titania coatings. Photocatalytic efficiency of the elaborated samples was evaluated from the conversion rate of nitrogen oxides. The present results showed that the suspension plasma spraying allows to produce reactive surfaces for the removal of air pollutants, that in the same working conditions, present a higher photocatalytic activity compared to that of the initial raw powders.
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Gopal, Vasanth, Sneha Goel, Geetha Manivasagam y Shrikant Joshi. "Performance of Hybrid Powder-Suspension Axial Plasma Sprayed Al2O3—YSZ Coatings in Bovine Serum Solution". Materials 12, n.º 12 (14 de junio de 2019): 1922. http://dx.doi.org/10.3390/ma12121922.
Resumen
Ceramic coatings on metallic implants are a promising alternative to conventional implants due to their ability to offer superior wear resistance. The present work investigates the sliding wear behavior under bovine serum solution and indentation crack growth resistance of four coatings, namely (1) conventional powder-derived alumina coating (Ap), (2) suspension-derived alumina coating (As), (3) composite Al2O3—20wt % Yittria stabilized Zirconia (YSZ) coating (AsYs) deposited using a mixed suspension, and (4) powder Al2O3—suspension YSZ hybrid composite coating ApYs developed by axial feeding plasma spraying, respectively. The indentation crack growth resistance of the hybrid coating was superior due to the inclusion of distributed fine YSZ particles along with coarser alumina splats. Enhanced wear resistance was observed for the powder derived Ap and the hybrid ApYs coatings, whereas the suspension sprayed As and AsYs coatings significantly deteriorated due to extensive pitting.
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Nowakowska, Monika, Paweł Sokołowski, Tomáš Tesař, Radek Mušálek y Tomasz Kiełczawa. "Al2O3-TiO2 coatings deposition by intermixed and double injection SPS concepts". Materials Science-Poland 39, n.º 4 (1 de diciembre de 2021): 599–614. http://dx.doi.org/10.2478/msp-2021-0046.
Resumen
Abstract This work focuses on the study on the novel hybrid method of simultaneous spraying from two different materials (Al2O3 and TiO2) by means of suspension plasma spraying (SPS) using submicron powder and water suspension. The goal was to attempt the deposition of intermixed alumina-titania coatings, namely: Al2O3 + 3 wt.% TiO2, Al2O3 + 13 wt.% TiO2, and Al2O3 + 40 wt.% TiO2. Such compositions are already used but in the form of conventionally plasma sprayed coatings, with micrometer-sized powder. Meanwhile, the injection of feedstocks with submicron-sized particles has not been established yet. In particular, this paper uses two routes of feedstock injection, (i) with the use of an intermixed suspension and (ii) a double injection of separate suspensions. The attention was paid to the characterization of the feedstock materials, description of deposition parameters as well as the morphology, microstructure, and phase composition of the obtained coatings. Among all coatings, Al2O3 + 40 wt.% TiO2 sprayed with double injection contained the most homogeneously distributed and melted splats. The results from this work demonstrate the possibility of coating deposition both by intermixed and double injection concepts but also the need for the further application-relevant optimization, related to the presence of intercolumnar gaps in the microstructure of the coatings.
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Liu, Liangwen, Mu Zhang, Xing’an Wang y Xudong Sun. "Preparation of MgO–Y2O3 Composite Ceramic by Aqueous Gel Casting". Journal of Nanoelectronics and Optoelectronics 16, n.º 3 (1 de marzo de 2021): 444–51. http://dx.doi.org/10.1166/jno.2021.2940.
Resumen
MgO–Y2O3 composite ceramics were prepared by gel-casting technology. The surface of MgO powder is passivated with H3PO4 ethanol solution. The treated powder can be dispersed in water with a dispersant. The powder surface modification process was verified by pH, Zeta potentials, Fourier transmission infrared absorption spectroscopy (FT-IR), the absorbance of suspension and rheological properties. The obtained stable suspensions were gel cast, dried, and sintered at 1400 °C for 30 min under 35 MPa. As a comparison, the powder was compressed by die pressing and sintered at the same temperature and pressure. After sintering, the MgO–Y2O3 composite ceramic with a theoretical density of 97.29% can be prepared by aqueous gel casting process. The properties of MgO–Y2O3 composite ceramic fabricated by gel casting are better than die pressing.
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Lewis, Paul O., David B. Cluck, Jessica D. Huffman, Amanda P. Ogle y Stacy D. Brown. "Stability of a pyrimethamine suspension compounded from bulk powder". American Journal of Health-System Pharmacy 74, n.º 24 (15 de diciembre de 2017): 2060–64. http://dx.doi.org/10.2146/ajhp160551.
Resumen
Abstract Purpose Development of a stability-indicating high-performance liquid chromatography (HPLC) method for pyrimethamine analysis, with subsequent application of that method to assess the 90-day stability of a pyrimethamine suspension compounded from bulk USP-grade pyrimethamine powder, is described. Methods A stability-indicating method of HPLC with ultraviolet detection specific to pyrimethamine was developed according to pharmacopeial recommendations and validated. The method was applied to investigate the stability of a 2-mg/mL pyrimethamine suspension in a vehicle consisting of Ora-Plus and Ora-Sweet (Perrigo) over a period of 90 days. Three replicate test preparations were stored at room temperature or refrigerated at 4.3–5.2 °C, and samples were analyzed in duplicate immediately after preparation and on study days 1, 2, 4, 7, 10, 14, 21, 30, 48, 60, 75, and 90. Results The 2-mg/mL suspension of pyrimethamine in Ora-Plus and Ora-Sweet retained 90–110% of the labeled potency to 90 days at both temperature ranges. However, color changes in the samples stored at room temperature observed at day 60 indicated that a beyond-use date less than 90 days from the preparation date should be specified when the suspension is to be stored at room temperature. Conclusion The study demonstrated that USP-grade pyrimethamine powder can be formulated as a 2-mg/mL suspension in a vehicle of Ora-Plus and Ora-Sweet and is stable when stored at room temperature and when refrigerated, in amber plastic bottles, for 48 and 90 days, respectively.
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Begliţa, Victoria, Mădălina Ungureanu-Iuga y Silvia Mironeasa. "Assessing the Features of Tomato Pomace Powder in Suspensions". Applied Sciences 13, n.º 4 (9 de febrero de 2023): 2235. http://dx.doi.org/10.3390/app13042235.
Resumen
The aim of this work was to investigate the physicochemical characteristics of dried tomato pomace and the viscoelastic behavior of suspensions obtained by the rehydration of dry, grinded tomato pomace and sieved with a particle size < 120 µm. Investigated systems comprised of three different dry tomato pomace powder (TP) concentrations (15, 20 and 25%) heat-treated at two temperatures (60 °C and 95 °C) corresponding to the “cold-break” and “hot-break”, during 30 min. The dynamic rheological properties and color parameters of the suspensions formulated were evaluated. The water activity, water absorption index, water retention capacity, pectin content and color parameters assessed revealed good properties of the dry tomato pomace powder (TP) to develop new products. Tomato pomace suspensions with different concentrations processed at different temperatures caused significant changes in rheological behavior. The viscoelastic properties of the TP suspension showed a much stiffer structure at 25% TP, processed at 90 °C. Instrumental color parameters a* and b* increased, while lightness (L*) decreased with concentration and temperature increase. These results could be useful to select the adequate concentration of TP to achieve a desired consistency of the product during processing with positive effects on quality parameters of the finite product.
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Panic, B. "Influence of the Bed Type on the Flow Resistance Change During the Two-Phase (Gas + Powder) Flow through the Descending Packed Bed". Archives of Metallurgy and Materials 59, n.º 2 (1 de junio de 2014): 795–800. http://dx.doi.org/10.2478/amm-2014-0135.
Resumen
Abstract The flow of gases with powder in the countercurrent to the charge materials occurs in many chemical processes. In the shaft metallurgical devices, the physical and chemical processes take place also in the countercurrent system. An important issue is that there are no disruptions of the flow in this multiphase system. Under real operating conditions of the device, the powder is generated within the process and its source is the charge or it is inserted to the device within the process procedure. In this system, a problem of bed particle suspension appears. That is why the author undertook investigations on the gas - powder flow in the descending bed. A physical model of this system was constructed. The experiments were performed and the influence of gas velocity, a type and size of the bed and powder particles as well as the powder concentration in the gas was established. Conditions when the descending bed suspension occurs were defined. In the case of physical model with glass materials, the suspension of bed did not occur. Therefore, investigations using beds of high alumina materials, blast furnace pellets and iron powder were performed. The results are presented below. When the bed of glass spheres was replaced with the bed of alumina spheres, a considerable increase in the volume of powder held up in the bed the gas flow resistance were observed. The surface properties of bed particles changed and better conditions for powder holdup were created. The actual gas velocity in the bed increased due to void fraction reduction. Replacement of the glass powder with the iron powder caused a change in the powder density, its surface properties and the shape factor. Greater amounts of the iron powder were held up in the bed and the gas flow resistance increased. Comparing the alumina particle bed - iron powder system to the blast furnace pellet bed - iron powder system, changes in the surface properties of bed particles and the void fraction of bed changed. The study results were the basis for defining conditions of the descending bed suspension.