scholarly journals New parametric transducer for resonant detectors: advances and room temperature test

2008 ◽  
Vol 122 ◽  
pp. 012031 ◽  
Author(s):  
M Bassan ◽  
R Ballantini ◽  
A Chincarini ◽  
G Gemme ◽  
M Iannuzzi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Temperature Test ◽  
Parametric Transducer

Conical Acrylic Windows Under Long Term Hydrostatic Pressure of 20,000 Psi

1970 ◽  
Vol 92 (1) ◽  
pp. 237-256
Author(s):  
J. D. Stachiw
Keyword(s):  
Hydrostatic Pressure ◽  
Room Temperature ◽  
Cone Angle ◽  
Diameter Ratio ◽  
Model Scale ◽  
Hydrostatic Loading ◽  
Pressure Application ◽  
Temperature Test

Conical acrylic windows with cone angles 30 deg ≤ α ≤ 150 deg have been subjected to sustained hydrostatic pressure of 20,000 psi for up to 1,000 hr duration. The thickness to minor diameter ratio (t/D) of the more than 200 windows varied from 0.750 to 2.000. Model scale windows served as the bulk of test specimens, and the majority of the tests were conducted at room temperature. Test findings indicate that only windows with t/D > 1 and cone angle α ≥ 60 deg will not fail in less than 1,000 hr of sustained hydrostatic loading although considerable cracking will take place. For optically acceptable service of 1000 hr duration under 20,000 psi hydrostatic pressure, the windows must have t/D ≥ 2 and a cone angle α ≥ 90 deg. The axial displacements of such windows after 1000 hr of hydrostatic loading at 20,000 psi, are approximately 0.1 times their minor diameter, with approximately 50 percent of this displacement taking place during the first hour of pressure application.

Life Testing and Reliability Behavior of Gan/Ingan/Aigan Light-Emitting Diodes

1998 ◽  
Vol 531 ◽  
Author(s):  
M. Osinski ◽  
D. L. Barton ◽  
C. J. Helms ◽  
N. H. Berg ◽  
C. H. Seager
Keyword(s):  
Room Temperature ◽  
Operating Conditions ◽  
Degradation Mechanisms ◽  
Final Temperature ◽  
Light Emitting ◽  
Electrical Pulses ◽  
Life Tests ◽  
Metal Migration ◽  
Device Lifetime ◽  
Temperature Test

AbstractOur studies of device lifetime and the main degradation mechanisms in Nichia blue LEDs date back to Spring 1994. Following the initial studies of rapid failures under high current electrical pulses, where metal migration was identified as the cause of degradation, we have placed a number of Nichia NLPB-500 LEDs on a series of life tests. The first test ran for 1000 hours under normal operating conditions (20 mA at 23 °C). As no noticeable degradation was observed, the second room temperature test was performed with the same devices but with a range of currents between 20 and 70 mA. After 1600 hours, some degradation in output intensity was observed in devices driven at 60 and 70 mA, but it was still less than 20%. The subsequent tests included stepping up the temperature by 10 °C in 500 h intervals up to a final temperature of 95 °C using the same currents applied in the second test. This work reviews the failure analysis that was performed on the degraded devices and the degradation mechanisms that were identified.

scholarly journals HOT HARDNESS MEASUREMENTS ON MATERIALS UP TO 600 °C DURING THE FIRST HOUR OF USING

2020 ◽  
Vol 27 ◽  
pp. 160-163
Author(s):  
Bruno Passilly ◽  
Lara Molenda
Keyword(s):  
Room Temperature ◽  
Applied Load ◽  
Vickers Microhardness ◽  
Maximum Load ◽  
Operating Environment ◽  
Simple Method ◽  
Micromechanical Characterization ◽  
Temperature Test ◽  
Conditions Of Employment ◽  
Hot Hardness

In the aeronautical field, materials are used in severe environmental conditions (temperature, atmosphere, exposure time ...), particularly for engine applications. In order to characterize the use of these materials in the evaluation of their properties, it is necessary to carry out tests in conditions close to their operating environment. Hot hardness is a simple method which can be applied on many different materials such as oxidized layers, coatings, composite materials, brazing cords, additive manufacturing materials. ONERA is developing micromechanical characterization means to carry out Vickers microhardness tests from room temperature up to 600 °C. In principle, a pyramidal punch is applied on the surface of a material and the applied load is continuously measured during indenter’s moving in the material. The material is tested locally under conditions close to the actual conditions of employment. The goal of this research is to improve microindentation in order to achieve temperature test campaigns up to 600 °C under a controlled atmosphere of argon and to validate a method to produce a series of results during the first hour of using up to 600 °C. Stainless material is studied to compare the evolution of its hot hardness properties versus different parameters such as load, holding time at the maximum load, atmosphere, and thermal duration. A discussion about these measurements and the technical limits of hot hardness technology is presented.

Effect of Temperature on Tensile Properties of Vulcanized Rubber

1934 ◽  
Vol 7 (2) ◽  
pp. 371-386
Author(s):  
A. A. Somerville ◽  
W. F. Russell
Keyword(s):  
High Temperature ◽  
Tensile Properties ◽  
Room Temperature ◽  
Point Of View ◽  
Effect Of Temperature ◽  
Curing Conditions ◽  
Vulcanized Rubber ◽  
Before And After ◽  
Temperature Test ◽  
Better Than

Abstract The tensile properties and tear resistance of a large number of commercial inner tubes, before and after aging by different methods, are studied at 0°, 25°, and 100° C. A number of uncured bus-truck tube stocks are also studied from the point of view of their capacity to withstand high temperatures. The effect of testing rubber at 100° C. as compared with room temperature is discussed; how some compounds collapse at 100° C., while others have tensile properties equal to, or better than those at 25°, is shown. The effect of testing artificially aged specimens at 100° C., as well as at 25° C., is discussed; the high-temperature test may reveal conditions of deterioration and overcure that are not noticeable in the 25° tests. The compounding and curing conditions that lead to high tensile properties at 100° C., as well as those which cause inferior quality, are discussed.

scholarly journals Particle disintegration of an important Brazilian manganese lump ore

2014 ◽  
Vol 67 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Geraldo Lúcio Faria ◽  
Nelson Jannotti ◽  
Fernando Gabriel da Silva Araújo
Keyword(s):  
High Temperatures ◽  
Large Scale ◽  
Room Temperature ◽  
Manganese Content ◽  
Economic Potential ◽  
Medium Temperature ◽  
Carbonate Decomposition ◽  
Disintegration Index ◽  
Temperature Test ◽  
Representative Samples

The manganese lump ore from Morro da Mina mine is typically silicate carbonated and presents a great economic potential for the ferroalloy companies installed in Minas Gerais. However, its low manganese content, associated with the lack of knowledge about its metallurgical properties makes it difficult for large scale application. This pioneering study aimed to amply investigate this lump ore's particle disintegration. One ton of ore from the mine was homogenized and quartered. Representative samples were characterized by different techniques, such as ICP-AES, XRD, SEM, BET and OM. Aiming to characterize particle disintegration, three parameters were proposed: Cold Disintegration Index (CDI), Decrepitation Index (DI) and Heating Disintegration Index (HDI). By using these indexes, it was possible to conclude that this manganese lump ore did not present significant disintegration at room temperature. At medium temperature test, slight decrepitation occurred, and at high temperatures, intense disintegration was detected. The carbonate decomposition and porosity growth were the main responsible factors for the ore hot particle disintegration.

scholarly journals Testing The Effect of Temperature, Storage Time, The Residual Test of Neem Oil Formulation (Azadirachta indica A. JUSS) and Bitung Formulation (Baringtonia asiatica) to Its Toxicity Against Large Cabbage Heart Caterpillar (Crocidolomia pavonana F)

2019 ◽  
Vol 1 (1) ◽  
pp. 27
Author(s):  
Neneng Sri Widayani ◽  
Afifah Nashirotul Haq ◽  
Lindung Tri Puspasari ◽  
Yusup Hidayat ◽  
Danar Dono
Keyword(s):  
Azadirachta Indica ◽  
Room Temperature ◽  
Storage Time ◽  
Residual Activity ◽  
Effect Of Temperature ◽  
Neem Oil ◽  
Oil Formulation ◽  
And Storage ◽  
Temperature Test ◽  
Temperature Storage

This study aims to determine the effect of temperature and storage time of neem formulation and residual test of neem formulation and bitung formulation to its toxicity on C. pavonana larvae. The formulations tested on the storability and temperature test using the newly prepared, neem formula has been stored for 19 months at room temperature 24.6-31,7 C, and stored in low temperature (4 degree Celsius) as well as controls. The toxicity of the neem oil formulation was tested at concentrations of 1%, 2%, and 3%. Residual testing was performed by spraying and the residual test samples were taken on days 0,1,2,3,5,7,9,11, and 13 days after application of insecticide spraying. The results showed that storage at low temperatures (temperature 4 degree Celsius) for 19 months can maintain the toxicity of the neem formulation to C. pavonana larvae. while storage at room temperature for 19 months resulted in a decreased toxicity. The residual activity of the neem formulations of concentration 0.8% and 2.4% ceased to cause the death C. pavonana larvae at the residual age of 13.34 days and 14.66 days. The activity of Bitung formulation concentration of 1.1% and 2.8% ceased to causing death C. pavonana larvae at the residual age of 11.33 days and 16.26 days.Keyword: Azadirachta indica, Baringtonia asiatica, Crocidolomia pavonana, Residue test, Storability test, Temperatures, Toxicity.

Sign in / Sign up

Export Citation Format

Share Document