INTERACTION EFFECT BETWEEN BEAM DIAMETER AND ENERGY DENSITY IN LASER-INDUCED TACTILE PERCEPTION

2018 ◽  
Vol 18 (07) ◽  
pp. 1840011
Author(s):  
MI-HYUN CHOI ◽  
HYUNG-SIK KIM ◽  
JI-HUN JO ◽  
JI-SUN KIM ◽  
JAE-HOON JUN ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Energy Density ◽  
Penetration Depth ◽  
Interaction Effect ◽  
Laser Energy ◽  
Tactile Sensation ◽  
Beam Diameter ◽  
Effective Energy ◽  
Effective Energy Transfer ◽  
Response Phase

This study aims to investigate the interaction effect between the beam diameter and energy density, which are perceived as laser-induced tactile perception by humans, by diversely varying the laser parameters, beam diameter, and energy. Eight healthy male college students of 23.5[Formula: see text][Formula: see text][Formula: see text]1.7 years participated in the study. The range of the beam diameter of the displayed laser stimulation was between 0.03[Formula: see text]mm and 8[Formula: see text]mm, and a total of 21 sizes were displayed. The laser energy was sequentially displayed from the minimum energy that can be displayed by one beam diameter to the maximum energy range that does not exceed the maximum permissible exposure (MPE) level since the energy varies according to the beam diameter. The laser energy was controlled by an optical density ([Formula: see text]) filter and was measured by an optical power meter (energy meter). Furthermore, the beam diameter was adjusted by moving the lens, which was confirmed with the beam profiler. The experimental test consists of the control phase (19[Formula: see text]s), stimulus phase (7[Formula: see text]s), and response phase (4[Formula: see text]s); the total duration of the test was 30[Formula: see text]s. The stimulus phase is the period in which stimulation was displayed on the skin through laser irradiation, and the stimulation was displayed by changing the beam diameter and the energy from the laser. The total number of beam diameter and energy pairs displayed to the subjects was 113 and 5 trials of irradiation were conducted for each pair. Stimulation perception response was recorded by pressing the response buttons during the response phase, and the responses were predefined as “no feeling,” “tactile sensation”, and “pain.” Through the extracted response data from the response phase, the beam diameter and energy density pair in which more than 50% of the subjects responded as having perceived tactile sensation were selected from the possible laser energy that could be displayed from one beam diameter. The simulation results showed that increasing the beam diameter increased the penetration depth, indicating an effective energy transfer to the skin. Therefore, increasing the beam diameter results in increased scattering, and hence increased penetration depth, and ultimately a more effective energy transfer. Therefore, increased beam diameter results in higher energy transfer efficiency, indicating that the required energy density by more than 50% of the subjects to perceive tactile sensation decreased.

A Study on the Luminescent Properties and Energy Transfer of Na2BaMgP2O8:Tb3+, Eu3+ Phosphor

2014 ◽  
Vol 700 ◽  
pp. 113-116
Author(s):  
Yu Jie Chen ◽  
Feng Lan Han ◽  
Zhao Luo
Keyword(s):  
Energy Transfer ◽  
Solid State ◽  
Powder Diffraction ◽  
Luminescent Properties ◽  
Solid State Lighting ◽  
Diffraction Measurement ◽  
Effective Energy ◽  
X Ray ◽  
Red Color ◽  
Effective Energy Transfer

Na2BaMgP2O8phosphors were synthesized by a standard solid state reaction and their luminescent properties were investigated. The phase structure was analyzed by X-ray powder diffraction measurement. Under the excitation of 365nm, Na2BaMgP2O8:Tb3+, Eu3+phosphors show two color bands of green and red color due to5D4−7F5transition of Tb3+ions and5D0−7F2transition of Eu3+ions, respectively. The emission intensity of Tb3+deceased with the increasing concentration of Eu3+, which verified that an effective energy transfer occurred from Tb3+to Eu3+in Na2BaMgP2O8host. The present study indicated that the phosphors have a high potential application in solid state lighting.

Luminescence Properties and Energy Transfer from Eu2+ to Tb3+ in Sr5(PO4)3F Phosphor

2013 ◽  
Vol 683 ◽  
pp. 199-202 ◽  
Author(s):  
Jia Yue Sun ◽  
Dian Peng Cui ◽  
Bing Xue ◽  
Guang Chao Sun ◽  
Hai Yan Du
Keyword(s):  
Energy Transfer ◽  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Single Phase ◽  
Emission Spectra ◽  
Effective Energy ◽  
Photoluminescence Excitation ◽  
Excitation Band ◽  
Effective Energy Transfer

A series of single-phase Sr5(PO4)3F: Eu2+, Tb3+, Na+ phosphors have been synthesized by high temperature solid-state reaction. The photoluminescence excitation and emission spectra, concentration effect and energy transfer from Eu2+ to Tb3+ are investigated in detail. The work shows that there is an effective energy transfer from Eu2+ to Tb3+, where Eu2+ reveals an intense excitation band from 280 nm to 400 nm, matching well with the emission of n-UV chips, and Tb3+ emits an intense green emitting light.

A multi-spacecraft analysis of energy transfer associated with near-Earth magnetic reconnection

2020 ◽  
Author(s):  
Sid Fadanelli ◽  
Benoit Lavraud ◽  
Francesco Califano
Keyword(s):  
Energy Transfer ◽  
High Frequency ◽  
Energy Exchange ◽  
Evolution Equations ◽  
Effective Energy ◽  
Large Database ◽  
Statistical Validity ◽  
Effective Energy Transfer ◽  
Energy Transfers ◽  
Plasma Theory

<p>We present an analysis of energy transfers in a reconnecting near-Earth plasma, obtained by interpreting MMS data within the framework of multi-fluid plasma theory. In our analysis, energy transfers are calculated and examined locally. This way, correlations between different mechanisms of energy exchange can be retrieved in all spatial and temporal detail provided by the high-frequency, multi-point sampling capacity of the four MMS satellites. <br>In particular, compressional effects are separated from effective sources in the energy density evolution equations, allowing to distinguish whether some effective energy transfer is occurring locally. A large database of MMS encounters with reconnecting current sheets is exploited in order to assess the statistical validity of all results presented.</p>

Optimization of parameters for SLS of WC-Co

2017 ◽  
Vol 23 (6) ◽  
pp. 1202-1211 ◽  
Author(s):  
Sanjay Kumar ◽  
Aleksander Czekanski
Keyword(s):  
Energy Density ◽  
Process Parameters ◽  
Laser Power ◽  
Laser Energy ◽  
Beam Diameter ◽  
Content Type ◽  
Powder Bed ◽  
Scan Speed ◽  
New Equation ◽  
Hatch Spacing

Purpose WC-Co is a well-known material for conventional tooling but is not yet commercially available for additive manufacturing. Processing it by selective laser sintering (SLS) will pave the way for its commercialization and adoption. Design/methodology/approach It is intended to optimize process parameters (laser power, hatch spacing, scan speed) by fabricating a bigger part (minimum size of 10 mm diameter and 5 mm height). Microstructural analysis, EDX and hardness testing is used to study effects of process parameters. Optimized parameter is ascertained after fabricating 49 samples in preliminary experiment, 27 samples in pre-final experiment and 9 samples in final experiment. Findings Higher laser power gives rise to cracks and depletion of cobalt while higher scan speed increases porosity. Higher hatch spacing is responsible for delamination and displacement of parts. Optimized parameters are 270 W laser power, 500 mm/s scan speed, 0.04 mm layer thickness, 0.04 mm hatch spacing (resulting in energy density of 216 J/mm3) and 200°C powder bed temperature. A part comprising of small hole of 2 mm diameter, thin cylindrical pin of 0.5 mm diameter and thin wall of 2 mm width bent up to 30° angle to the base plate is fabricated. In order to calculate laser energy density, a new equation is introduced which takes into account both beam diameter and hatch spacing unlike old equation does. In order to calculate laser energy density, a new equation is formulated which takes into account both beam diameter and hatch spacing unlike old equation does. WC was not completely melted as intended giving rise to partial melting-type binding mechanism. This justified the name SLS for process in place of SLM (Selective Laser Melting). Research limitations/implications Using all possible combination of parameters plus heating the part bed to maximum shows limitation of state-of-the-art commercial powder bed fusion machine for shaping hardmetal consisting of high amount of WC (83 wt. per cent). Practical implications The research shows that microfeatures could be fabricated using WC-Co which will herald renewed interest in investigating hardmetals using SLS for manufacturing complex hard tools, molds and wear-resistance parts. Originality/value This is the first time micro features are successfully fabricated using WC-Co without post-processing (infiltration, machining) and without the help of additional binding material (such as Cu, Ni, Fe).

Effective Energy Transfer Process in a Dyad Molecule of Pyrene and C60

2002 ◽  
Vol 31 (10) ◽  
pp. 968-969 ◽  
Author(s):  
Mamoru Fujitsuka ◽  
Hongxia Luo ◽  
Yasujiro Murata ◽  
Noriyuki Kato ◽  
Osamu Ito ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Transfer Process ◽  
Energy Transfer Process ◽  
Effective Energy ◽  
Effective Energy Transfer

scholarly journals Inorganic nanocrystal-dynamic porous polymer assemblies with effective energy transfer for sensitive diagnosis of urine copper

2020 ◽  
Vol 11 (44) ◽  
pp. 12187-12193
Author(s):  
Xujiao Ma ◽  
Yajie Yang ◽  
Rongchen Ma ◽  
Yunfeng Zhang ◽  
Xiaoqin Zou ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Electrical Properties ◽  
Porous Polymer ◽  
Optical And Electrical Properties ◽  
Effective Energy ◽  
Inorganic Particles ◽  
Structural Order ◽  
Effective Energy Transfer

Despite their remarkable mechanical, optical, and electrical properties, inorganic particles and dynamic polymer assemblies encounter difficulties in their compatibility with regards to structural order and complexity.

HIGHLY EFFICIENT BLUE ELECTROLUMINESCENCE BASED ON AGGREGATION INDUCED EMISSION MATERIAL AS THE HOST

2013 ◽  
Vol 01 (03) ◽  
pp. 1340012
Author(s):  
XIAO YANG ◽  
SHAOQING ZHUANG ◽  
LEI WANG ◽  
JING HUANG ◽  
ZHEN LI
Keyword(s):  
Energy Transfer ◽  
High Efficiency ◽  
Effective Energy ◽  
Maximum Luminance ◽  
Device Structure ◽  
Light Emitting ◽  
Aggregation Induced Emission ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Effective Energy Transfer

High-efficiency blue organic light-emitting devices (OLEDs) have been fabricated using tetraphenylethene (TPE)-based conjugated molecule TPE-2Cz, which exhibited aggregation induced emission (AIE) properties, as blue host material and BUBD-1 as dopant emitter. With an optimized device structure, the effective energy transfer from the AIE host to BUBD-1 was achieved. The optimized device exhibits the peak EL efficiencies of 10.3 cd/A, 5.4% and 9.8 lm/W, with Commission Internationale de l'Eclairage coordinates of (0.15, 0.31) and a maximum luminance of 14550 cd/m2.

Sign in / Sign up

Export Citation Format

Share Document