Strength degradation of lightguide fibres in room temperature water

1996 ◽  
Vol 32 (8) ◽  
pp. 761 ◽  
Author(s):  
C.R. Kurkjian ◽  
M.J. Matthewson
Keyword(s):  
Room Temperature ◽  
Strength Degradation ◽  
Temperature Water

ChemInform Abstract: Sonogashira Couplings of Aryl Bromides: Room Temperature, Water Only, No Copper.

ChemInform ◽  
2009 ◽  
Vol 40 (2) ◽  
Author(s):  
Bruce H. Lipshutz ◽  
David W. Chung ◽  
Brian Rich
Keyword(s):  
Room Temperature ◽  
Aryl Bromides ◽  
Temperature Water

Room-Temperature, Water-Promoted, Radical-Coupling Reactions of Phenols with tert-Butyl Nitrite

Synlett ◽  
2017 ◽  
Vol 28 (16) ◽  
pp. 2153-2156 ◽  
Author(s):  
Wen-Ting Wei ◽  
Hongze Liang ◽  
Wen-Ming Zhu ◽  
Weida Liang ◽  
Yi Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivative ◽  
Tert Butyl ◽  
Radical Coupling ◽  
Air Atmosphere ◽  
Cross Coupling Reaction ◽  
Temperature Water

A radical–radical cross-coupling reaction of phenols with tert-butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C–N bonds under an air atmosphere at room temperature, providing the ortho-nitrated phenol derivative in moderate to good yields.

Thermal Resistance of Fly Ash Geopolymers with Alumina as Additive

2018 ◽  
Vol 281 ◽  
pp. 182-188
Author(s):  
Yong Sing Ng ◽  
Yun Ming Liew ◽  
Cheng Yong Heah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin
Keyword(s):  
Elevated Temperature ◽  
Fly Ash ◽  
Thermal Resistance ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Room Temperature ◽  
Strength Degradation ◽  
Alumina Addition ◽  
Higher Temperature ◽  
Temperature Exposure

The present work investigates the effect of alumina addition on the thermal resistance of fly ash geopolymers. Fly ash geopolymers were synthesised by mixing fly ash with activator solution (A mixture of 12M sodium hydroxide and sodium silicate) at fly ash/activator ratio of 2.5 and sodium silicate/sodium hydroxide ratio of 2.5. The alumina (0, 2 and 4 wt %) was added as an additive. The geopolymers were cured at room temperature for 24 hours and 60°C for another 24 hours. After 28 days, the geopolymers was heated to elevated temperature (200 - 1000°C). For unexposed geopolymers, the addition of 2 wt % of alumina increased the compressive strength of fly ash geopolymers while the strength decreased when the content increased to 4 wt.%. The temperature-exposed geopolymers showed enhancement of strength at 200°C regardless of the alumina content. The strength reduced at higher temperature exposure (> 200°C). Despite the strength degradation at elevated temperature, the strength attained was relatively high in the range of 13 - 45 MPa up to 1000°C which adequately for application as structural materials.

Effects of Direct Thermal Method Processing Parameters on Mechanical Properties of Semisolid A6061 Feedstock

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
M. F. M. Tajudin ◽  
A. H. Ahmad ◽  
M. M. Rashidi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Processing Parameters ◽  
Holding Time ◽  
Thermal Method ◽  
Pouring Temperature ◽  
Porosity Level ◽  
Experimental Works ◽  
Temperature Water

This paper highlights the effects of pouring temperature and holding time on the mechanical properties of aluminium 6061 semisolid feedstock billets. The semisolid metal feedstock billets were prepared by a direct thermal method (DTM), in which the molten metal was poured into a cylindrical copper mould with a different combination of pouring temperature and holding time before it was solidified in room temperature water. The results show that the sample with pouring temperature slightly above aluminium 6061 liquidus temperature has the lowest porosity, thereby the highest mechanical properties value. The sample with a pouring temperature of 660 °C and holding time of 60 s has the density, tensile strength and hardness properties of 2.701 g/cm3, 146.797 MPa, and 86.5 HV, respectively. Meanwhile, the sample at a pouring temperature of 640 °C and holding time of 20 s has density, tensile strength and hardness properties of 2.527 g/cm3, 65.39 MPa, and 71.79 HV, respectively. The density and fractography tests were conducted to confirm the existence of porosity within the samples. The results from these experimental works suggested that the mechanical properties of DTM semisolid feedstock billet merely depended on processing parameters, which influenced the porosity level within the feedstock billet, thus directly affected their mechanical properties.

scholarly journals In-situ Neutron Tomography on Mixing Behavior of Supercritical Water and Room Temperature Water in a Tubular Flow Reactor

2015 ◽  
Vol 69 ◽  
pp. 564-569 ◽  
Author(s):  
Seiichi Takami ◽  
Ken-ichi Sugioka ◽  
Kyohei Ozawa ◽  
Takao Tsukada ◽  
Tadafumi Adschiri ◽  
...  
Keyword(s):  
Supercritical Water ◽  
Room Temperature ◽  
Flow Reactor ◽  
Neutron Tomography ◽  
Mixing Behavior ◽  
Tubular Flow Reactor ◽  
Tubular Flow ◽  
Temperature Water

Adverse Effects of Long-Term Ice-Cold Water Drink on Rat Liver Function and Histology

2020 ◽  
Author(s):  
Said Abdul Ghafour Saeedy ◽  
Ahmad Faisal Faiz ◽  
Marjan Nikbakhtzadeh ◽  
Bagher Minaei Zangi ◽  
Mansoor Keshavarz
Keyword(s):  
Liver Function ◽  
Rat Liver ◽  
Room Temperature ◽  
Cold Water ◽  
The Body ◽  
Control Group ◽  
Male Wistar Rats ◽  
Temperature Water ◽  
Care Period

Drinking ice-cold water is prohibited in Avicenna’s “The Canon of Medicine” book in which he emphasized that ice-cold water drinking was hazardous for the body organs such as the liver. Little information can be found regarding the effects of ice-cold fluid drinks on liver and its probable sequels on this vital organ. Accordingly, we investigated the effects of long-term ice-cold water drink on the rat liver function and histology. Eighteen male Wistar rats, weighing 180±20 g, were randomly divided into three groups of six as two months ice-cold water drink, CW2M; three months ice-cold water drink, CW3M; and three months room temperature water drink; control group. Upon completion of the care period, a blood sample has been taken for liver enzymes and lipid profile assessment. Liver tissue has also been used for histological studies of H&E staining and microscopic examination. Histological findings showed hepatocellular micro-vesicle formation, necrosis and derangement of the cellular cords and infiltration of Kupffer cells in ice-cold water taken animals. Serum TGs, VLDL-C and ALP significantly increased with sound decrease in FBS and LDL-C in ice-cold water taken animals. It seems that long-term ice-cold water has deleterious functional and structural effects on the liver.

Study on the Thermal Fatigue Resistance of Cr17Mn10Ni3 Heat-Resistant Steel

2011 ◽  
Vol 194-196 ◽  
pp. 1326-1332
Author(s):  
Jun You Liu ◽  
Jie Liu ◽  
Qing he Zhao ◽  
Jin Xiu Song
Keyword(s):  
Thermal Fatigue ◽  
Strain Energy ◽  
Room Temperature ◽  
Elastic Strain Energy ◽  
Fatigue Property ◽  
Water Cooling ◽  
High Concentration ◽  
Heat Resistant Steel ◽  
Metallurgical Structure ◽  
Temperature Water

In order to prolong the life of inner liner of coke can, the thermal fatigue property of Cr17Mn10Ni3 heat-resisting steel was analyzed and studied from cast metallurgical structure, the morphology of crack surface and cross-section, the injury factor by OM, SEM, photoshop and imagetool software. The results shows, Cr17Mn10Ni3 has a good thermal fatigue property because of the microstructure with good thermal conductivity, austenite matrix and break carbide lying in treelike crystals. It decreases the innerstress and postpones the time of crack formation and extension, during the process with 1100°C and room- temperature water cooling. The cracks mainly appear in the phase interfaces between carbides and matrix, ferrite and austenite, and grain boundaries. The thin and deep cracks with high concentration are beneficial to relax the elastic strain energy. But a single and thick crack easily widens and deepens to be detrimental to the thermal fatigue property.

Room-temperature water-vapor adsorption in niobium

1990 ◽  
Vol 33 (8) ◽  
pp. 847-848
Author(s):  
Yu. D. Gorchakov ◽  
�. T. Frantsuz ◽  
S. N. Gershkovich ◽  
V. M. Khavinson ◽  
T. N. Musta
Keyword(s):  
Water Vapor ◽  
Room Temperature ◽  
Water Vapor Adsorption ◽  
Vapor Adsorption ◽  
Temperature Water

Investigating the properties of subcritical water extraction with pharmaceutical tablets

2014 ◽  
Vol 92 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Jillian N. Murakami ◽  
Kevin B. Thurbide
Keyword(s):  
Sample Preparation ◽  
Microcrystalline Cellulose ◽  
Room Temperature ◽  
Subcritical Water ◽  
Water Extraction ◽  
Subcritical Water Extraction ◽  
Over The Counter ◽  
Pharmaceutical Tablets ◽  
Optimized Conditions ◽  
Temperature Water

The properties of subcritical water extraction (SWE) in the sample preparation of pharmaceutical tablets were investigated. Tablets comprised of microcrystalline cellulose excipients broke apart up to 80 times faster in subcritical water than they did in room temperature water, while those containing starch readily broke apart in either. Tablets containing starch were also observed to gelatinize or “paste” over several SWE conditions, impeding subsequent filtration and analysis. This effect was avoidable, however, since it was demonstrated to disappear with increases in extraction time and temperature or decreases in sample size. Using SWE, two common over-the-counter pharmaceuticals were extracted under optimized conditions from tablets comprised of either microcrystalline cellulose or starch excipients. Analyte recoveries of 95% or more were obtained at 150 °C for vitamin C (ascorbic acid) tablets in as little as 8 min for the extraction of a whole intact tablet, 6 min for two half tablets, and 5 min for a ground tablet. By comparison, this occurred at 250 °C in just 2 min for an intact slice of an acetaminophen tablet. Reproducibility was generally quite good with these trials producing RSD values of less than 2%. The results indicate that SWE can be a potentially viable and efficient method for the sample preparation of whole, sliced, or ground pharmaceutical tablets, and further exploration of this approach is promising.

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