scholarly journals Preliminary Investigation on Sodium Alginate Extracted from Sargassum Subrepandum of Red Sea of Eritrea as Tablet Binder

2011 ◽  
Vol 3 (3) ◽  
pp. 609-618 ◽  
Author(s):  
N. S. Basha ◽  
R. Rekha ◽  
A. Letensie ◽  
S. Mensura
Keyword(s):  
High Temperature ◽  
Sodium Alginate ◽  
Room Temperature ◽  
Preliminary Investigation ◽  
Hydroxypropyl Methylcellulose ◽  
Extraction Methods ◽  
Binding Property ◽  
Alkaline Extraction ◽  
Suitable Alternative ◽  
Binding Strength

Natural polysaccharides hold advantages over synthetic polymers for conventional and novel dosage forms, because these are non-toxic, less expensive, and biodegradable. These can also be modified to tailor-made materials and thus can compete with the available synthetic excipients. Therefore, the aim of present work is to extract sodium alginate from the seaweed S. subrepandum to assess its binding property using propranolol as model drug. Sodium alginate was extracted by room-temperature alkaline extraction and high-temperature (80°C) alkaline extraction methods. Binding strength was evaluated by using two different formulations i.e., formulation 1 with sodium alginate as a binder and formulation 2 with hydroxypropylmethylcellulose (HPMC) as reference standard. The two tablet formulations were evaluated and compared for parameters such as friability, hardness and disintegration. The percentage yield was found to be 17.5% w/w by room-temperature alkaline extraction and 21%w/w by high-temperature extraction method. The results obtained for all tested parameters for tablets with sodium alginate were found within acceptable range of USP standards. It was also founded that both sodium alginate and HPMC have similar binding strength at similar concentration. So, it can be concluded that sodium alginate of S. subrepandum can be used as suitable alternative binder in tablet formulations.Keywords: Sargassum subrepandum; Sodium alginate; Hydroxypropyl methylcellulose; Friability; Hardness; Disintegration.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi:10.3329/jsr.v3i3.6770                     J. Sci. Res. 3 (3), 619-628 (2011)

Sodium alginate assisted construction of ZnSnO 3 microspheres enhanced HCHO sensing performance under UV illumination at room temperature

2019 ◽  
Vol 14 (14) ◽  
pp. 1381-1384
Author(s):  
Jie Chen ◽  
Zhihua Ying ◽  
Peng Zheng ◽  
Rongfa Gao ◽  
Jinbang Mei
Keyword(s):  
Sodium Alginate ◽  
Room Temperature ◽  
Uv Illumination ◽  
Sensing Performance

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

Nanocomposite Polyurethane Foams Via POSS Blends

2002 ◽  
Vol 733 ◽  
Author(s):  
Brock McCabe ◽  
Steven Nutt ◽  
Brent Viers ◽  
Tim Haddad
Keyword(s):  
High Temperature ◽  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Polyurethane Foams ◽  
Development Projects ◽  
Polymer Systems ◽  
Polyurethane Resin ◽  
Military Development

AbstractPolyhedral Oligomeric Silsequioxane molecules have been incorporated into a commercial polyurethane formulation to produce nanocomposite polyurethane foam. This tiny POSS silica molecule has been used successfully to enhance the performance of polymer systems using co-polymerization and blend strategies. In our investigation, we chose a high-temperature MDI Polyurethane resin foam currently used in military development projects. For the nanofiller, or “blend”, Cp7T7(OH)3 POSS was chosen. Structural characterization was accomplished by TEM and SEM to determine POSS dispersion and cell morphology, respectively. Thermal behavior was investigated by TGA. Two methods of TEM sample preparation were employed, Focused Ion Beam and Ultramicrotomy (room temperature).

FANSTEEL 85 METAL

Alloy Digest ◽  
1981 ◽  
Vol 30 (6) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Creep Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Good Combination ◽  
Bend Strength ◽  
Temperature Performance

Abstract FANSTEEL 85 METAL is a columbium-base alloy characterized by good fabricability at room temperature, good weldability and a good combination of creep strength and oxidation resistance at elevated temperatures. Its applications include missile and rocket components and many other high-temperature parts. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cb-7. Producer or source: Fansteel Metallurgical Corporation. Originally published December 1963, revised June 1981.

MAGNESIUM AZ31B

Alloy Digest ◽  
1962 ◽  
Vol 11 (9) ◽  
Keyword(s):  
High Temperature ◽  
Magnesium Alloy ◽  
Physical Properties ◽  
Room Temperature ◽  
Heat Treating ◽  
General Purpose ◽  
Bearing Strength ◽  
Temperature Performance ◽  
Wrought Magnesium Alloy ◽  
Metal Products

Abstract Magnesium AZ31B is a general purpose wrought magnesium alloy for room temperature service. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as creep. It also includes information on low and high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Mg-53. Producer or source: The Dow Metal Products Company.

Mechanical Alloying Behavior in the Nb-Si, Ta-Si, and Nb-Ta-Si Systems

1988 ◽  
Vol 133 ◽  
Author(s):  
K. S. Kumar ◽  
S. K. Mannan
Keyword(s):  
High Temperature ◽  
Mechanical Alloying ◽  
Mechanical Milling ◽  
Room Temperature ◽  
Crystalline Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase

ABSTRACTThe mechanical alloying behavior of elemental powders in the Nb-Si, Ta-Si, and Nb-Ta-Si systems was examined via X-ray diffraction. The line compounds NbSi2 and TaSi2 form as crystalline compounds rather than amorphous products, but Nb5Si3 and Ta5Si3, although chemically analogous, respond very differently to mechanical milling. The Ta5Si3 composition goes directly from elemental powders to an amorphous product, whereas Nb5Si3 forms as a crystalline compound. The Nb5Si3 compound consists of both the tetragonal room-temperature α phase (c/a = 1.8) and the tetragonal high-temperature β phase (c/a = 0.5). Substituting increasing amounts of Ta for Nb in Nb5Si3 initially stabilizes the α-Nb5Si3 structure preferentially, and subsequently inhibits the formation of a crystalline compound.

scholarly journals Room-temperature oxygen vacancy migration induced reversible phase transformation during the anelastic deformation in CuO

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lei Li ◽  
Guoxujia Chen ◽  
He Zheng ◽  
Weiwei Meng ◽  
Shuangfeng Jia ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxygen Vacancy ◽  
Room Temperature ◽  
High Temperature Superconductivity ◽  
Experimental Investigations ◽  
Solid State Chemistry ◽  
Vacancy Migration ◽  
Scientific Disciplines ◽  
Anelastic Deformation ◽  
Reversible Phase

AbstractFrom the mechanical perspectives, the influence of point defects is generally considered at high temperature, especially when the creep deformation dominates. Here, we show the stress-induced reversible oxygen vacancy migration in CuO nanowires at room temperature, causing the unanticipated anelastic deformation. The anelastic strain is associated with the nucleation of oxygen-deficient CuOx phase, which gradually transforms back to CuO after stress releasing, leading to the gradual recovery of the nanowire shape. Detailed analysis reveals an oxygen deficient metastable CuOx phase that has been overlooked in the literatures. Both theoretical and experimental investigations faithfully predict the oxygen vacancy diffusion pathways in CuO. Our finding facilitates a better understanding of the complicated mechanical behaviors in materials, which could also be relevant across multiple scientific disciplines, such as high-temperature superconductivity and solid-state chemistry in Cu-O compounds, etc.

scholarly journals Formulation and Optimization of Sodium Alginate Polymer Film as a Buccal Mucoadhesive Drug Delivery System Containing Cetirizine Dihydrochloride

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 619
Author(s):  
Krisztián Pamlényi ◽  
Katalin Kristó ◽  
Orsolya Jójárt-Laczkovich ◽  
Géza Regdon
Keyword(s):  
Drug Delivery ◽  
Tensile Strength ◽  
Sodium Alginate ◽  
Drug Delivery System ◽  
Delivery System ◽  
Polymer Films ◽  
Hydroxypropyl Methylcellulose ◽  
Chemical Properties ◽  
Active Pharmaceutical Ingredient ◽  
Swallowing Problems

Currently, pharmaceutical companies are working on innovative methods, processes and products. Oral mucoadhesive systems, such as tablets, gels, and polymer films, are among these possible products. Oral mucoadhesive systems possess many advantages, including the possibility to be applied in swallowing problems. The present study focused on formulating buccal mucoadhesive polymer films and investigating the physical and physical–chemical properties of films. Sodium alginate (SA) and hydroxypropyl methylcellulose (HPMC) were used as film-forming agents, glycerol (GLY) was added as a plasticizer, and cetirizine dihydrochloride (CTZ) was used as an active pharmaceutical ingredient (API). The polymer films were prepared at room temperature with the solvent casting method by mixed two-level and three-level factorial designs. The thickness, tensile strength (hardness), mucoadhesivity, surface free energy (SFE), FTIR, and Raman spectra, as well as the dissolution of the prepared films, were investigated. The investigations showed that GLY can reduce the mucoadhesivity of films, and CTZ can increase the tensile strength of films. The distribution of CTZ proved to be homogeneous in the films. The API could dissolve completely from all the films. We can conclude that polymer films with 1% and 3% GLY concentrations are appropriate to be formulated for application on the buccal mucosa as a drug delivery system.

scholarly journals Synthesis of Organic Ligands via Reactions of 4-Benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione with N-Nucleophiles

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hassan Kabirifard ◽  
Pardis Hafez Taghva ◽  
Hossein Teimouri ◽  
Niloofar Koosheshi ◽  
Parastoo Javadpour ◽  
...  
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Aromatic Amines ◽  
Room Temperature ◽  
Organic Ligands ◽  
Carboxyl Group ◽  
Primary Aromatic Amines

The reaction of 4-benzoyl-5-phenylamino-2,3-dihydrothiophene-2,3-dione (1) with aminoheteroaryls, lamotrigine, 1,3-diaminoheteroaryls, dapsone, NH2R (hydroxylamine, DL-1-phenylethylamine, and metformin), and 4,4′-bipyridine in THF/H2O (1 : 1) at room temperature led to 3-N-phenylthiocarbamoyl-2-butenamides 2–5, while that with naphthylamines and 1,3-phenylenediamine in ethanol at high temperature led to 5-phenylamino-2,5-dihydrothiophene-2-ones 6–8 as organic ligands in the medium to good yields. These showed the nucleophilic attacks of N-nucleophiles, except primary aromatic amines, on thioester carboxyl group (C-2) of thiophene-2,3-dione ring 1. However, the nucleophilic attacks of primary aromatic amines on the carbonyl group (C-3) of thiophene-2,3-dione 1 occurred in the form of substituted thiophenes.

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