scholarly journals The disappearance of vitexin from Tartary buckwheat flour-water mixtures after the hydrothermal treatment

Fagopyrum ◽  
2021 ◽  
Vol 38 (2) ◽  
pp. 31-34
Author(s):  
Mateja Germ ◽  
Alena Vollmannova ◽  
Július Árvay ◽  
Tomáš Tóth ◽  
Aleksandra Golob
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Initial Temperature ◽  
Tartary Buckwheat ◽  
Water Mixture ◽  
Biological Functions ◽  
Aqueous Methanol ◽  
Mixture Samples ◽  
Buckwheat Flour ◽  
Control Samples

Vitexin is an apigenin flavone glucoside with known biological functions. This research reported the effects of initial temperature treatments of Tartary buckwheat flour mixture with water and time of methanol extraction from the cooked doughs on the amount of extractable vitexin. The mixtures of flour and water were initially hydrothermally treated at temperatures from 25 °C to 95 °C. Afterward the mixtures were cooked at 95 °C for 20 min, and vitexin extracted at room temperature with 80% aqueous methanol for 20 min, 2 h and 8 h. The extractable vitexin was extracted during the same extraction times for the control in the nonhydrothermally treated Tartary buckwheat flour-water mixture samples. For the cooked dough samples, the hydrothermal treatments were important in terms of the extractability of vitexin. The extractable vitexin persisted in the control samples during the extraction time up to 8 hours, while in the hydrothermally treated and cooked dough samples, there remained none detectable vitexin. The high-temperature initial treatments during dough preparation appeared not to prevent the degradation of vitexin in Tartary buckwheat flour.

scholarly journals PENGARUH PANJANG STACK SELUBUNG KABEL TERHADAP PERUBAHAN SUHU PADA SISTEM PENDINGIN TERMOAKUSTIK

2017 ◽  
Vol 2 (2) ◽  
pp. 119
Author(s):  
Indah Kharismawati ◽  
Hanif Rafika Putri
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Room Temperature ◽  
Initial Temperature ◽  
Temperature Drop ◽  
Maximum Temperature ◽  
Thermoelectric Cooler ◽  
Thermoelectric Coolers ◽  
Temperature Changes ◽  
Sheath Material

Research on environmentally friendly thermo-acoustic coolants uses a heat exchanger from the cable sheath material. The resonator tube used in the thermoelectric cooler is a 5.25 cm diameter PVC (polyvinyl chloride) tube with a length of 87 cm. Variations in stack lengths of 4cm, 5cm, 6cm, 7cm, and 8cm were performed to obtain results on thermoelectric coolers. Results are available on the use of stack length 4 cm high temperature 21.6 oC from the initial temperature), the stack length 5 cm high temperature 21.1 oC from the initial temperature (room temperature), the stack length of 6 cm resulted in a maximum temperature drop of 22.6 oC from the initial temperature (room temperature), the stack length of 7 cm resulted in a maximum temperature drop of 22.0 oC from the initial temperature (room temperature), while the stack length of 8 cm resulted in a decrease in temperature maximum of 23.3 oC from the initial temperature (room temperature). Keywords: Thermoacoustic, stack, temperature changes.

Performance of Al2 O3 Ceramics with Different Thermal Histories

2014 ◽  
Vol 636 ◽  
pp. 61-64
Author(s):  
Dai Dong Guo ◽  
Hui Liu ◽  
Shi Quan Liu
Keyword(s):  
High Temperature ◽  
Service Time ◽  
Dimensional Stability ◽  
Room Temperature ◽  
Initial Temperature ◽  
Bending Strength ◽  
Cold Isostatic Pressing ◽  
Rapid Cooling ◽  
Isostatic Pressing ◽  
Thermal Histories

The mechanic properties mainly the room temperature bending strength and the creep of the Al2O3 ceramic specimens which were prepared by cold isostatic pressing and had undergone different thermal histories have been measured and compared. The results suggest that the bending strength of the ceramic increases after high temperature soaking. The ceramic can withstand cyclic rapid cooling with an initial temperature of 200 °C. The sample has shown a very good dimensional stability after a long service time (50h) at 1550 °C.

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 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.

Sign in / Sign up

Export Citation Format

Share Document