Search query: Performance test result of LUCE (laser utilizing communications equipment) engineering model

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abstract: NASDA (National Space Development Agency of Japan) have developed (OICETS (Optical Inter Orbit Communications Engineering Test Satellite) since 1993 in order to get the acquisition, tracking and pointing technology for optical inter satellite communications through the in orbit experiment with ARTEMIS (Advanced Relay and TEchnology Mission Satellite) of European Space Agency. The engineering model of the optical terminal called LUCE (Laser Utilizing Communications Equipment) was tested and its optical performance was evaluated during the thermal vacuum test. The on axis intensity transmitted from the terminal was about 560 MW/Sr with 90 mW of the averaged semiconductor laser output. The full width of the far field pattern of the emitted beam at the point of 1/e2 was about 9.4 (mu) radian.
author_names: Keizo Nakagawa

Akio Yamamoto

Masahiro Toyoda
title: Performance test result of LUCE (laser utilizing communications equipment) engineering model
venue: LASE
year: 2000

abstract: For the purpose of providing a larger space for designing scaffold and replacing the current method of bone injury repair and bone transplantation by using CAD design with PCL HA as the material of the porous circular structure that can meet the requirements of the mechanical strength of the material. The CT 3D reconstruction model of the hydroxyapatite scaffold was designed and constructed. CT laser scanning was used to study the structure of the femur and lumbar spine with eight male rabbits, using HA PCL as material and using 3D printing technology to make bone tissue engineering scaffold. The blank form of the scaffold, the diameter and porosity of the fiber scaffold, and the loading force, the maximum load and the deformation value of the mechanical data were measured. The resulted showed that the pore connectivity rate of each scaffold in each group was 100% there was no significant difference between the total parameters of the stent and the micro structure parameters. When the load is 320N, the three different cylindrical stents under the maximum pressure, the loading force, deformation and deformation of no significant difference. The result of the present work implied that the combination of CT and CAD reverse technology can complete the design and manufacture of complex bone tissue engineering scaffold materials, there was no significant difference in the physical properties of the porous scaffolds with different loads.
author_names: Shigang Wang

Yuhang Fan

Shufeng Jiang
title: 3D Printing PCL HA Bone Tissue Engineering Scaffold and Its Performance Test
year: 2016

abstract: The Atmospheric Processing Module (APM) is a Mars In Situ Resource Utilization (ISRU) technology designed to demonstrate conversion of the Martian atmosphere into methane for use as rocket propellant for an ascent vehicle. The Martian atmosphere mainly consists of 95% carbon dioxide (CO2) and residual argon and nitrogen. APM utilized cryocoolers for CO2 acquisition from a simulated Martian atmosphere and pressure. The captured CO2 was sublimated and pressurized as a feedstock into the Sabatier reactor, which converted CO2 and hydrogen to methane and water. The Sabatier reaction occurred over a packed bed reactor filled with Ru/Al2O3 catalyst pellets. During performance testing at high flow rates, failure of the Sabatier catalyst occurred, which was detected by unwanted byproducts at elevated reaction temperatures. A Sabatier catalyst failure study was initiated after this event. This led to an effort to develop a model that could determine acceptable flow rates and predict the temperature profile in order to avoid catalyst damage and identify system tolerances. Validation of a computational model with experimental results also aids in long duration system development for reactor scaling purposes. This paper discusses the experimental results of the APM Sabatier tests, as well as a small scale Sabatier reactor that was set up for further model validation. The thermal and kinetic modeling approaches are discussed, as well as results of the APM catalyst characterization which included x ray powder diffraction and x ray photoelectron spectroscopy.
author_names: Anne J Meier

Malay G Shah

Paul E Hintze

Elspeth M Petersen

Anthony C Muscatello
title: Mars Atmospheric Conversion to Methane and Water: An Engineering Model of the Sabatier Reactor with Characterization of Ru/Al2O3 for Long Duration Use on Mars
year: 2017

abstract: In order to estimate and demonstrate the performance of Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer (TANSO FTS) and Cloud and Aerosol Imager (TANSO CAI) under the environmental condition on orbit, the Engineering Model (EM) for TANSO FTS and CAI have been developed and demonstrated. The TANSO FTS has three narrow bands detectable regions; 0.76, 1.6 and 2micrion (Band1, 2 and 3) with /2.5cm maximum optical path difference, and a wide band (5.5 14.3micron in thermal near infrared region. The TANSO CAI is a radiometer of ultraviolet (UV) visible, and SWIR, which has 4 spectral band regions with 1 dimensional array CCDs. The initial performance tests have been carried out in the laboratory and the thermal vacuum chamber. The Signal to Noise Ratio (SNR) the polarization sensitivity (PS) Instantaneous Field Of View (IFOV) and response for FTS and CAI, and also the Instrumental Line Shape Function (ILSF) for FTS have been characterized in this test by introducing the light emitted from the black body, halogen lamp and the tunable diode laser. As a results of these experiments, it is appeared that the some modification of system for manufacturing the proto flight model (PFM) is required, and now in progressing. In addition to these characterizations, the newly developed tests, such as the stray light measurement and micro vibration test, are applied on TANSO FTS to estimate the effect on orbit. These tests methods and results are presented in this paper.
author_names: Hiroshi Suto

Takahiro Kawashima

Kei Shiomi

Tomoko Kina

Akihiko Kuze

Tomoyuki Urabe

Shuji Kawakami

Yutaka Kaneko

Takashi Hamazaki
title: The performance test results for engineering model (EM) of thermal and near infrared sensor for carbon observation (TANSO) on GOSAT
venue: SPIE Optical Engineering Applications
year: 2007

abstract: Rock bolt is a support system extensively utilized in Civil and Mining Engineering applications, especially for underground excavations projects. The main function of a rock bolt is to stabilize the rock mass around the opening of an excavation by fastening to further stable formations. Previous technical work developed pull out testing in order to improve understanding regarding the mechanical response within this system. However, due to limitations with conventional laboratory methods of capturing strain, there still exists a lack of understanding in this mechanical response at the micro scale; more specifically, in the detailed strain profile distribution along fully grouted rock bolts. Aiming to address this knowledge gap, two research programmes were conducted and will be addressed in this paper: numerical modelling of pull out tests through finite element method (FEM) and hybrid finite discrete element method (FDEM) and laboratory pull out tests on concrete samples utilizing a newly developed distributed optical strain sensing technology that provides a spatial resolution of 0.65 mm in order to capture the strain along the rock bolt. Experimental and modelling results were compared to evaluate the numerical approaches feasibility and their correspondence with the experiments. FDEM modelling demonstrated ability in capturing general mechanical behavior, while the FEM software seems to be a good option to be utilized as a design tool, yet improvements to the interaction model are necessary to achieve a better calibration with experimental results.
author_names: Nicholas Vlachopoulos

Daniel Cruz

Bryan S A Tatone

Andrea Lisjak

O K Mahabadi

Bradley Forbes

Carla Carrapatoso
title: The Performance of Axially Loaded, Fully Grouted Rock Bolts Based on Pull Out Experiments Utilizing Fiber Optics Technology and Associated Numerical Modelling of Such Support Elements
venue: Geotechnical and Geological Engineering
year: 2019

abstract: Abstract Laser marking is one of the effective and efficient ways of permanent marking process in the different engineering materials like composites, ceramics and any other hard metals and alloys. The present investigation deals with the experimental analysis on laser marking process using diode pumped Nd:YAG laser considering several process parameters for example lamp current, pulse repetition rate and laser scanning speed. The Response Surface Methodology (RSM) based experimental design was adopted to study in depth the influence of these parameters on marking performance criteria such as mark width, mark depth and mark intensity. Based on experimental results, the second order mathematical models were established. Multi performance optimized parametric combination was achieved to obtain high quality marking using developed models and desirability functions. Moreover, in order to determine the most influencing parameter on the responses, Sensitivity Analysis (SA) was performed on the test results obtained from experimentation as well as predictive models. SEM and optical microscopic images were also analyzed to examine the quality aspects of laser marking on gallium nitride.
author_names: Ishwer Shivakoti

Golam Mohammad Kibria

Bal Bahadur Pradhan
title: Predictive model and parametric analysis of laser marking process on gallium nitride material using diode pumped Nd:YAG laser
venue: Optics Laser Technology
year: 2019

abstract: Atomic Clock Ensemble in Space (ACES) is a European Space Agency (ESA) project to be deployed externally to the Columbus Laboratory on the International Space Station (ISS) Two high performance atomic clocks on board ACES generate a frequency reference with stability and accuracy at the 1x10 16 level. The performance of the ACES clock signal results from the combination of the good short term stability of an active hydrogen maser (SHM) and the long term stability and accuracy of a primary standard based on samples of laser cooled Cs atoms (PHARAO) The two clocks are controlled by two servo loops, the first stabilizing the PHARAO local oscillator on SHM clock signal, the second correcting the long term instabilities of SHM using the error signal generated by the PHARAO Cs resonator. This frequency reference, distributed to the ground by a link in the microwave domain is used to perform comparisons of distant clocks and to test Einstein's theory of general relativity. ACES main instrument and subsystems have now reached a high technology readiness level, demonstrated by the completion and the successful test of their engineering models. In particular, a dedicated test campaign has recently verified the performance of the ACES system, where PHARAO and SHM, locked together via the ACES servo loops, are operated as a unique oscillator to generate the ACES frequency reference. The test campaign conducted at CNES premises in Toulouse between July and November 2009 has concluded the engineering models phase, releasing the manufacturing of the ACES flight models. The setup of the ACES system test campaign, the specific tests performed, and the achieved results will be presented and discussed.
author_names: B Leger

Luca Stringhetti

Didier Massonnet

Ch Delaroche

F Picard

M P Hess

L Cacciapuoti

S J Feltham

Rudolph Much

Rosario Nasca

T Vudali

Christophe Salomon

Ph M Laurent
title: Results of the ACES engineering model system test
venue: EFTF 2010 24th European Frequency and Time Forum
year: 2010

abstract: Test model plays an important role in specification testing processes and improves test efficiency. At present test model performance is too simple, relatively few types of performance indicators, this paper presents the test model WTMS which based on user behavior. Besides user loader, response time, CPU utilization rate, WTMS increase the success rate of requests, the actual request time, the best of concurrent users and the maximum number of concurrent user. And performance testing of the subjects are divided into user behavior factors, business factors, the software elements, hardware elements, and test strategy factors. Base on educational administration management system, results show that WTMS model improves test efficiency and accuracy of test results.
author_names: Deng Lu-juan

Fan Naimei

Su Yikun

Pan Kaijie

Chen Pei
title: Research on performance test model of Web application
year: 2013

abstract: This paper presents a universal engineering model, which can be used to formulate both counterflow and crossflow cooling towers. By using fundamental laws of mass and energy balance, the effectiveness of heat exchange is approximated by a second order polynomial equation. Gauss Newton and Levenberg Marquardt methods are then used to determine the coefficients from manufactures data. Compared with the existing models, the new model has two main advantages: (1) As the engineering model is derived from engineering perspective, it involves fewer input variables and has better description of the cooling tower operation; (2) There is no iterative computation required, this feature is very important for online optimization of cooling tower performance. Although the model is simple, the results are very accurate. Application examples are given to compare the proposed model with commonly used models. NOMENCLATURE Cpw: specific heat of water under constant pressure; Cs: derivative of saturated ha with respect to Tw; c0 c5: curve fitting constants; dk: search direction of optimization method; Fdata: computation value of ea; ha: enthalpy of air; hs,w: saturation air enthalpy at Tw; hs,wb: saturation air enthalpy at Twb; J(uk) Jacobian matrix of uk; ma: mass flow rate of air; me: mass flow rate of evaporation; ma: mass flow rate of air; mm: mass flow rate of makeup water; mw: mass flow rate of water; NTU: number of transfer units; m: ratio of air to water effective capacitance rate; Qe: heat evaporation rate of loss water; Qrej: heat rejection rate of cooling tower; Tdb: dry bulb temperature of air; Tm: temperature of makeup water; Tw: temperature of water; Twb: wet bulb temperature of air; uk: the value of c0 c5 of the kth iteration; ea: heat transfer effectiveness of Braun's model; h: enthalpy difference with respect to T; T: approach of cooling tower; lk: control coefficients; Subscript i: inlet; o: outlet; INTRODUCTION Cooling towers are commonly used to dissipate heat from heat sources to heat sink (ambient environment) Their applications are typically in Heating Ventilation and Air Conditioning (HVAC) systems and power generators, etc. Heat rejection of cooling towers is accomplished by heat and mass transfer between hot water droplets and ambient air. Although cooling towers are relatively inexpensive and normally consume around ten percent of the whole system energy, their operation has significant effect to the energy consumption of other related subsystems (RMIRA 1995; Michel 1995) Therefore, optimizing cooling tower performance will not only increase the tower efficiencies but also has direct effect to other subsystems. As such, there has been some research interest in this area. Austin (1997) recommended regression methods to create the models of each component in air conditioning systems for predicting and optimizing the system performance. Flake (1997) utilized a different regression technique to determine parameters of the cooling tower model developed by Braun (1989) and to build a predictive model for optimal supervisory control strategies. However, due to the lacking of an effective and precise model for cooling towers, which is essential to estimate and verify the energy savings by different optimization strategies, the research on optimization of cooling tower performance is still in the primary stage. Attempts to develop the cooling tower models have a relative long history, the first such work may trace back to 1925, when Merkel developed a practical model for cooling tower operation, which has been the basis for most modern cooling tower analyses. In his model, the water loss of evaporation is neglected and the Lewis number is assumed to be one in order to simplify the analysis. However, as evaporate water cannot be neglected in cooling tower operation, Merkel's model is not accurate enough and not suitable for real applications. A more rigorous analysis of a cooling tower model that relaxed Merkel's restriction was given by Sutherland (1983) In 1989, Braun developed "effectiveness models" for cooling towers, which utilized the assumption of a linearized air saturation enthalpy and the modified definition of number of transfer units. The models were useful for both design and system simulation and has been adopted by the simulation software TRNSYS (SEL 2000) However, Braun's model needs iterative computation to obtain the output results and is not suitable for online optimization. Bernier (1994) reviewed the heat and mass transfer process in cooling towers at water droplet level and analyzed an idealized spray type tower in one dimension, which is useful for cooling tower designers, but no much information is provided to plant operators. Soylemez (1999) presented a quick method for estimating the size and performance of forced draft countercurrent cooling towers and experimental results were used to validate the prediction formulation. Unfortunately, this model also need iterative computation and not suitable for online optimization. In this paper, a universal engineering model, which can be used to formulate both counterflow and crossflow cooling towers, is proposed. Extending the methods provided by Merkel and Braun and using fundamental laws of mass and energy balance, the effectiveness of heat exchange is approximated by a second order polynomial equation. Gauss Newton and Levenberg Marquardt methods are then used to determine the coefficients from manufactures data. Compared with the existing models, the new model has two main advantages: (1) As the engineering model is derived from engineering perspective, it involves fewer input variables and has better description of the cooling tower operation; (2) There is no iterative computation required, this feature is very important for online optimization of cooling tower performance. Although the model is simple, the results are very accurate. Application examples are given for both counterflow and crossflow to compare the proposed model with commonly used models. COOLING TOWER MODEL ANALYSIS The mechanism of heat and mass transfer between ambient air and condenser water inside a cooling tower is illustrated in Figure 1. Figure 1. Schematic representation of heat and mass transfer in the cooling tower AIR WATER i a m i a h o a h o a m
author_names: L Lu
title: A Universal Engineering Model For Cooling Towers
year: 2014

abstract: The NASA s Evolutionary Xenon Thruster (NEXT) project is developing an advanced ion propulsion system for future NASA missions for solar system exploration. An engineering model (EM) power processing unit (PPU) for the NEXT project was designed and fabricated by L 3 Communications under contract with NASA Glenn Research Center (GRC) This modular PPU is capable of processing up from 0.5 to 7.0 kW of output power for the NEXT ion thruster. Its design includes many significant improvements for better performance over the state of the art PPU. The most significant difference is the beam supply which is comprised of six modules and capable of very efficient operation through a wide voltage range because of innovative features like dual controls, module addressing, and a high current mode. The low voltage power supplies are based on elements of the previously validated NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) PPU. The highly modular construction of the PPU resulted in improved manufacturability, simpler scalability, and lower cost. This paper describes the design of the EM PPU and the results of the bench top performance tests.
author_names: Luis R Pinero

M B Hopson

Philip C Todd

Brian R Wong
title: Performance of the NEXT Engineering Model Power Processing Unit
year: 2007