scholarly journals Effect of Temperature on Reliability and Degradation of 0.63?m Laser Diode

2012 ◽  
Vol 9 (1) ◽  
pp. 141-147
Author(s):  
Baghdad Science Journal
Keyword(s):  
Temperature Dependence ◽  
Laser Diode ◽  
System Application ◽  
Effect Of Temperature ◽  
Reliability Test ◽  
Test Results ◽  
Degradation Behaviour ◽  
Light Power ◽  
Aging Test ◽  
Power Operation

The reliability of optical sources is strongly dependent on the degradation and device characteristics are critically dependent on temperature. The degradation behaviours and reliability test results for the laser diode device (Sony-DL3148-025) will be presented .These devices are usually highly reliable. The degradation behaviour was exhibited in several aging tests, and device lifetimes were then estimated. The temperature dependence of 0.63?m lasers was studied. An aging test with constant light power operation of 5mW was carried out at 10, 25, 50 and 70°C for 100hours. Lifetimes of the optical sources have greatly improved, and these optical sources can be applied to various types of transmission systems. Within this degradation range, the device life for system application is estimated to be more than 100 h at 70 ºC at a constant power of 5mW.

scholarly journals Constant Optical Power Operation of an Ultraviolet LED Controlled by a Smartphone

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4707
Author(s):  
Ching-Hua Chen ◽  
Jia-Jun Zhang ◽  
Chang-Han Wang ◽  
Yu-Chia Chang ◽  
Pinghui S. Yeh
Keyword(s):  
Uv Light ◽  
Light Output ◽  
Color Temperature ◽  
Constant Light ◽  
Driving Voltage ◽  
Light Power ◽  
Monolithically Integrated ◽  
Uv Led ◽  
Power Operation ◽  
Arduino Uno

Constant light power operation of an ultraviolet (UV) LED based on portable low-cost instrumentation and a monolithically integrated monitoring photodiode (MPD) has been reported for the first time. UV light irradiation has become one of the essential measures for disinfection and sterilization. Monitoring and maintaining a specified light power level is important to meet the criteria of sterilization. We built a module composed of a monolithically integrated UV LED and MPD, a transimpedance amplifier, an Arduino Uno card, a digital-to-analog converter and a Bluetooth transceiver. An Android App that we wrote remotely controlled the UV LED module via Bluetooth. The Arduino Uno card was programmed to receive demands from the smartphone, sent a driving voltage to the LED and returned the present MPD voltage to the smartphone. A feedback loop was used to adjust the LED voltage for maintaining a constant light output. We successfully demonstrated the functioning of remote control of the App, and the resultant UV LED measured power remained the same as the setting power. This setup can also be applied to visible or white LEDs for controlling/maintaining mixed light’s chromaticity coordinates or color temperature. With such controlling and internet capability, custom profiling and maintenance of precision lighting remotely would be possible.

scholarly journals Temperature Dependence of Limiting Fluorescence Anisotropy of POPOP in Cellulose Acetate Film

1985 ◽  
Vol 40 (6) ◽  
pp. 559-561
Author(s):  
A. Kawski ◽  
A. Kubicki ◽  
I. Weyna ◽  
I. Janić
Keyword(s):  
Temperature Dependence ◽  
Cellulose Acetate ◽  
Fluorescence Anisotropy ◽  
Thermal Relaxation ◽  
Effect Of Temperature ◽  
Torsional Vibrations ◽  
Slow Increase ◽  
Cellulose Acetate Film ◽  
Luminescent Centre

The effect of temperature (103 K < T < 303 K) upon the limiting fluorescence anisotropy r0 of POPOP was investigated in a cellulose acetate film. A slow increase in r0 was observed when reducing the temperature. Based on the Jabłoński theory, the frequency of the torsional vibrations of POPOP was determined to be w = 1.3 x 1012s−1. The depolarization due to these torsional vibrations was found to occur immediately following excitation during the thermal relaxation of the luminescent centre, thus somewhat lowering the value of the fundamental fluorescence anisotropy rf to the limiting r0 value.

Natural Aging Test for CF3011/BA9916-II Composite in Marine Environment

2014 ◽  
Vol 633-634 ◽  
pp. 408-412
Author(s):  
Xu Liu ◽  
Li Wang ◽  
Wu Jun Huo ◽  
Yue Liang Chen ◽  
Yuan Ling Lei
Keyword(s):  
Marine Environment ◽  
Moisture Absorption ◽  
Natural Aging ◽  
Plastic Behavior ◽  
Test Results ◽  
Aging Test ◽  
Interlaminar Shear ◽  
Weather Resistance ◽  
Carbon Fiber Epoxy ◽  
Marine Climate

Abstract: A form of static coupon following the boat was developed to carry the natural aging test for CF3011/BA9916-II composite in marine environment, and the weather resistance of composite in marine climate was studied. The changes of the morphology of the composite were observed, the changes of the quality ,tensile strength and interlaminar shear strength for specimen were analyzed, and the aging regulation was studied combining with the mechanism of hygrothermal aging for carbon fiber epoxy composite. The test results showed that with the aging time increasing, the moisture absorption of the composite increased, the mechanical strength decreased , and the plastic behavior of the material was showed.

The Influence of Understanding Accounting Information Systems, Leadership Style, Employee Motivation, and Work Discipline in Employees Performance KC BRI Sidoarjo

Academia Open ◽  
2021 ◽  
Vol 5 ◽  
Author(s):  
Shafrino Wahyu ◽  
Herman Ernandi
Keyword(s):  
Information Systems ◽  
Leadership Style ◽  
Hypothesis Test ◽  
Accounting Information ◽  
Research Data ◽  
Reliability Test ◽  
Test Results ◽  
Accounting Information Systems ◽  
Validity Test ◽  
Systems Leadership

This research aims to know the influence of understanding Accounting Information Systems, Leadership Style, Employees Motivation, and Work Discipline in Employees Performance at KC BRI Sidoarjo. The instrument is in the form of google forms to get research data. This research data collection is validity test and reliability test. The hypothesis is that there is an the influence of understanding accounting information systems, leadership style, employees motivation, and work discipline in employees performance. The analytical tool used to test the hypothesis is SPSS version 18. The test results based on the validity test show that all questions on Google Forms are declared valid. While the test results based on the reliability test of all variables, the value of cronbach's alpha > 0,6 means that it is declared reliable and for the results of the Hypothesis Test in the form of T-Statistic and R-Square, it states that there is an influence between understanding accounting information systems, leadership style, employees motivation, and work discipline in employees performance. This is shown from the results of tcount for the variable understanding of the accounting information system (X1) of 2.113, the variable of leadership style (X2) of 2.101, the variable of employees motivation (X3) of 2.114, and the variable of work discipline (X4) of 2.189.

scholarly journals Effect of Temperature on the Tribological Properties of Selected Thermoplastic Materials Cooperating with Aluminium Alloy

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7318
Author(s):  
Anita Ptak ◽  
Paula Taciak ◽  
Wojciech Wieleba
Keyword(s):  
Aluminium Alloy ◽  
Contact Pressure ◽  
Tribological Properties ◽  
Polymer Materials ◽  
Effect Of Temperature ◽  
Test Results ◽  
Friction Process ◽  
Before And After ◽  
Pin On Disc ◽  
Two Parameters

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.

scholarly journals Multi-objective design optimization of a permanent magnet axial flux eddy current brake

2019 ◽  
pp. 998-1011
Author(s):  
RASUL TARVIRDILU ASL ◽  
HÜSEYİN MURAT YÜKSEL ◽  
OZAN KEYSAN
Keyword(s):  
Eddy Current ◽  
Effect Of Temperature ◽  
Test Results ◽  
Algorithm Optimization ◽  
Axial Flux ◽  
Multiobjective Genetic Algorithm ◽  
Aerospace Applications ◽  
Eddy Current Damper ◽  
Brake Performance ◽  
Speed Characteristic

The main aim of this study is to optimize an axial flux eddy current damper to be used in a specific aviation application. Eddy current dampers are more advantageous compared to conventional mechanical dampers as they are maintenance-free due to contactless structure and have higher reliability, which is very desirable in aerospace applications. An initial eddy current brake prototype is manufactured and the test results are used to verify the 3-D finite element simulations. The effect of temperature on the brake performance is investigated. Finally, a multiobjective genetic algorithm optimization is applied to find the optimum pole number and geometric dimensions of the eddy current brake in order to achieve the desired torque-speed characteristic while the total weight of the brake is minimized. It is found that the mass and volume of the initial prototype can be halved by implementing this optimization algorithm.

scholarly journals Pengembangan Soal Penalaran Model TIMSS untuk Mengukur High Order Thinking (HOT)

2018 ◽  
Vol 1 (1) ◽  
pp. 20
Author(s):  
Indri Nurwahidah
Keyword(s):  
Student Response ◽  
Reliability Test ◽  
Due Diligence ◽  
Research Development ◽  
Test Results ◽  
Multiple Choice Questions ◽  
Student Responses ◽  
Good Product ◽  
Measurement Results ◽  
High Order Thinking

The research was conducted to determine the characteristics and forms of matter; similarly determine the validity, reliability, as well as the students' response to the measurement results HOT reasoning about TIMSS models to measure student HOT developed. The method used is the research development. Products in the form of multiple choice questions as well as the reasons of the students' answers. Student responses obtained from the questionnaire responses the students after using such a matter. Based on the criteria of due diligence in a very good product. Characteristic of reasoning about TIMSS models which contain components reasoning refers to the TIMSS. About the validity of the overall test results show that the question is valid and feasible to use to measure student HOT. Reliability test results indicate that the matter is reliable and can be used well. Student response after use problems in the excellent category, obtained a percentage of 82.66%. HOT measurement results in the category of students is still low, at SMPN 8 Semarang amounted to 51.54%, SMP Kartika III-2 Semarang amounted to 31.16%, and the MTs NU amounted to 47.68% Ungaran. Problem reasoning models that have been developed decent TIMSS used to measure student HOT.

TEMPERATURE DEPENDENCE OF ELECTRICAL RESISTANCE OF INDIVIDUAL CARBON NANOTUBES AND CARBON NANOTUBES NETWORK

2012 ◽  
Vol 26 (21) ◽  
pp. 1250136 ◽  
Author(s):  
SAJJAD DEHGHANI ◽  
MOHAMMAD KAZEM MORAVVEJ-FARSHI ◽  
MOHAMMAD HOSSEIN SHEIKHI
Keyword(s):  
Carbon Nanotubes ◽  
Temperature Dependence ◽  
Electric Fields ◽  
Electrical Resistance ◽  
Electrode Materials ◽  
Effect Of Temperature ◽  
Electrode Spacing ◽  
Single Wall Carbon Nanotubes ◽  
Tube Metal

We present a model to understand the effect of temperature on the electrical resistance of individual semiconducting single wall carbon nanotubes (s-SWCNTs) of various diameters under various electric fields. The temperature dependence of the resistance of s-SWCNTs and metallic SWCNTs (m-SWCNTs) are compared. These results help us to understand the temperature dependence of the resistance of SWCNTs network. We experimentally examine the temperature dependence of the resistance of random networks of SWCNTs, prepared by dispersing CNTs in ethanol and drop-casting the solution on prefabricated metallic electrodes. Examining various samples with different electrode materials and spacings, we find that the dominant resistance in determination of the temperature dependence of resistance of the network is the resistance of individual tubes, rather than the tube–tube resistance or tube–metal contact resistance. It is also found that the tube–tube resistance depends on the electrode spacing and it is more important for larger electrode spacings. By applying high electric field to burn the all-metallic paths of the SWCNTs network, the temperature dependence of the resistance of s-SWCNTs is also examined. We also investigate the effect of acid treatment of CNTs on the temperature dependence of the resistance of SWCNTs and also multi-wall CNTs (MWCNTs) networks.

Updated Analysis of Circuit Reliability Test Results

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000253-000259
Author(s):  
Milton Watts
Keyword(s):  
Failure Analysis ◽  
Detailed Analysis ◽  
Continuous Improvement ◽  
Oil And Gas ◽  
Lessons Learned ◽  
Reliability Test ◽  
Circuit Reliability ◽  
Test Results ◽  
Life Testing ◽  
Gas Market

The downhole oil and gas market is continually pushing for higher reliability at higher temperatures. Satisfying this need requires continuous improvement, driven by failure analysis of both internal testing and field returns. This paper discusses recent lessons learned from on-going tests. Results of unpowered circuit assembly tests are reviewed. Also, a detailed analysis of separate powered life testing is presented. The internal testing results are further discussed in the context of field return data.

Temperature Dependence and Martensitic Transformation of Ti50Pt50 Shape Memory Alloys

2014 ◽  
Vol 1019 ◽  
pp. 379-384
Author(s):  
M.P. Mashamaite ◽  
Hasani Rich Chauke ◽  
Rosinah Mahlangu ◽  
P.E. Ngoepe
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Temperature Dependence ◽  
Effect Of Temperature ◽  
Displacive Transformation ◽  
B2 Phase ◽  
Recent Experimental Work

Shape memory alloys (SMAs) are a fascinating group of metals that have two remarkable properties, the shape memory effect and superelasticity. The TiPt structure with the B2 phase has been reported to undergo a reversible displacive transformation to B19 martensite at about 1200K. However, this system could serve in principle as the basis of high-temperature shape memory alloys. Molecular dynamics study of martensitic transformation in platinum titanium alloys was performed to investigate the effect of temperature dependence on B2 and B19 structures at 50 at.%Pt. The NPT ensemble was used to determine the properties of these systems and we found good comparisons with recent experimental work. The temperature dependence of TiPt shows potential martensitic change when B19 is heated to extreme high temperatures of 273K up to 1573K.

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