Nanoparticle-Assisted Heating Utilizing a Low-Cost White Light Source

2013 ◽  
Vol 4 (4) ◽  
Author(s):  
Robert A. Taylor ◽  
Jun Kai Wong ◽  
Sungchul Baek ◽  
Yasitha Hewakuruppu ◽  
Xuchuan Jiang ◽  
...  
Keyword(s):  
White Light ◽  
Particle Concentration ◽  
Low Cost ◽  
Surface Heat ◽  
Temperature Fields ◽  
Gold Nanospheres ◽  
Ir Camera ◽  
Photothermal Heating ◽  
20 Nm ◽  
Surface Heat Treatments

In this experimental study, a filtered white light is used to induce heating in water-based dispersions of 20 nm diameter gold nanospheres (GNSs)—enabling a low-cost form of plasmonic photothermal heating. The resulting temperature fields were measured using an infrared (IR) camera. The effect of incident radiative flux (ranging from 0.38 to 0.77 W·cm−2) and particle concentration (ranging from 0.25–1.0 × 1013 particles per mL) on the solution's temperature were investigated. The experimental results indicate that surface heat treatments via GNSs can be achieved through complementary tuning of GNS solutions and filtered light.

scholarly journals Aggregation affects optical properties and photothermal heating of gold nanospheres

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yiru Wang ◽  
Zhe Gao ◽  
Zonghu Han ◽  
Yilin Liu ◽  
Huan Yang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cross Section ◽  
Laser Heating ◽  
Dipole Approximation ◽  
Gold Nanospheres ◽  
Extinction Cross Section ◽  
Heating Efficiency ◽  
Photothermal Heating ◽  
New Framework ◽  
Laser Calorimetry

AbstractLaser heating of gold nanospheres (GNS) is increasingly prevalent in biomedical applications due to tunable optical properties that determine heating efficiency. Although many geometric parameters (i.e. size, morphology) can affect optical properties of individual GNS and their heating, no specific studies of how GNS aggregation affects heating have been carried out. We posit here that aggregation, which can occur within some biological systems, will significantly impact the optical and therefore heating properties of GNS. To address this, we employed discrete dipole approximation (DDA) simulations, Ultraviolet–Visible spectroscopy (UV–Vis) and laser calorimetry on GNS primary particles with diameters (5, 16, 30 nm) and their aggregates that contain 2 to 30 GNS particles. DDA shows that aggregation can reduce the extinction cross-section on a per particle basis by 17–28%. Experimental measurement by UV–Vis and laser calorimetry on aggregates also show up to a 25% reduction in extinction coefficient and significantly lower heating (~ 10%) compared to dispersed GNS. In addition, comparison of select aggregates shows even larger extinction cross section drops in sparse vs. dense aggregates. This work shows that GNS aggregation can change optical properties and reduce heating and provides a new framework for exploring this effect during laser heating of nanomaterial solutions.

Real time fall detection using infrared cameras and reflective tapes under day/night luminance

2021 ◽  
pp. 1-16
Author(s):  
E. Ramanujam ◽  
S. Padmavathi
Keyword(s):  
Low Cost ◽  
Age Groups ◽  
Orientation Angle ◽  
Fall Detection ◽  
Living Environment ◽  
Vision Systems ◽  
Ir Camera ◽  
Cluttered Environments ◽  
Infrared Cameras ◽  
Time Fall

Falls are the leading cause of injuries and death in elderly individuals who live alone at home. The core service of assistive living technology is to monitor elders’ activities through wearable devices, ambient sensors, and vision systems. Vision systems are among the best solutions, as their implementation and maintenance costs are the lowest. However, current vision systems are limited in their ability to handle cluttered environments, occlusion, illumination changes throughout the day, and monitoring without illumination. To overcome these issues, this paper proposes a 24/7 monitoring system for elders that uses retroreflective tape fabricated as part of conventional clothing, monitored through low-cost infrared (IR) cameras fixed in the living environment. IR camera records video even when there are changes in illumination or zero luminance. For classification among clutter and occlusion, the tape is considered as a blob instead of a human silhouette; the orientation angle, fitted through ellipse modeling, of the blob in each frame allows classification that detects falls without pretrained data. System performance was tested using subjects in various age groups and “fall” or “non-fall” were detected with 99.01% accuracy.

A Study on the Birefringence Measurement in Injection Molded Parts Using Two Different Laser Sources and R-G-B Separation of White Light

2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon
Keyword(s):  
White Light ◽  
Low Cost ◽  
Main Idea ◽  
Injection Molding Process ◽  
Molding Process ◽  
Laser Method ◽  
High Productivity ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.

scholarly journals A New Test Facility for Testing of Cooled Gasturbine Components

1998 ◽  
Author(s):  
Ulf R. Rådeklint ◽  
Christer S. Hjalmarsson
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Temperature Fields ◽  
Test Facility ◽  
Operating Point ◽  
Ir Camera ◽  
Turbine Cooling ◽  
Air Temperatures ◽  
Turbine Vanes ◽  
Conventional Instrumentation

A high pressure hot test facility for cooled gas turbine components has been developed for use in turbine cooling research. In this facility, heat transfer tests for a sector of real turbine vanes can be performed under continuous operation. The heat transfer tests are performed at an operating point that is scaled down from the real engine operating point. The compressor can deliver air at the rate of up to 10 kg/s at 20 bars. Air temperatures of up to 1170 K can be achieved by using an oil-fired combustor. Besides conventional instrumentation such as thermocouples and pressure probes, the facility is equipped with an IR-camera to map two-dimensional wall temperature fields. Hot wire anemometry and an LDV system are used to determine mean and fluctuating velocity components. This paper describes design and performance of the test facility as well as the control and measurement equipment. The test and evaluation procedures used for testing of cooled gas turbine vanes are also presented.

scholarly journals Synchronous fluorescence as a green and selective tool for simultaneous determination of bambuterol and its main degradation product, terbutaline

2018 ◽  
Vol 5 (10) ◽  
pp. 181359 ◽  
Author(s):  
Samah Abo El Abass ◽  
Heba Elmansi
Keyword(s):  
Degradation Product ◽  
Low Cost ◽  
Reference Method ◽  
Cost Effective ◽  
Zero Crossing ◽  
Cost Effective Method ◽  
Validation Parameters ◽  
Main Degradation Product ◽  
20 Nm

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.

Effects of Chemical Modification of Indium-Tin-Oxide with Benzene Derivates on the Performance of Organic Photovoltaic Cells of ITO/CuPc/C60/BCP/Al

2011 ◽  
Vol 1288 ◽  
Author(s):  
Khayankhyarvaa Sarangerel ◽  
Altantsetseg Delgerjargal ◽  
Byambasuren Delgertsetseg ◽  
Chimed Ganzorig
Keyword(s):  
Chemical Modification ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Copper Phthalocyanine ◽  
Low Cost ◽  
Photovoltaic Cells ◽  
Organic Photovoltaic ◽  
Organic Thin Film ◽  
Organic Pv ◽  
20 Nm

ABSTRACTOrganic thin film photovoltaic (PV) cells have attracted attention because of their ease of fabrication and potential for low cost production. In this paper, we study the effects of chemical modification of indium-tin-oxide (ITO) on the performance of organic PV cells. The organic PV cells are fabricated, with the cell configuration of ITO/copper phthalocyanine (CuPc) (20 nm)/fullerene (C60) (40 nm)/Al with and without bathocuproine (BCP) (10 nm) between C60 and Al. By the use of para-substituted benzenesulfonyl chlorides with different terminal groups of H- and Cl-, the energy offset at the ITO/CuPc interface is tuned widely depending upon the interface dipoles and thus the correlation between the change in the ITO work function and the performance of the PV cells by chemical modification is examined.

Highly bright and stable white-light-emitting cadmium-free Ag,Mn co-doped Zn–In–S/ZnS quantum dots and their electroluminescence

2018 ◽  
Vol 6 (38) ◽  
pp. 10233-10240 ◽  
Author(s):  
Wen-Jin Zhang ◽  
Chun-Yang Pan ◽  
Fan Cao ◽  
Haoran Wang ◽  
Xuyong Yang
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Low Cost ◽  
Synthetic Approach ◽  
One Pot ◽  
Light Emitting ◽  
Co Doped

Optimized white light emitting Ag,Mn:Zn–In–S quantum dots (QDs) were synthesized via a simple, scalable, reproducible, and low-cost one-pot non-injection synthetic approach.

Multi-Level Storage in Lateral Phase Change Memory: From 3 to 16 Resistance Levels

2013 ◽  
Vol 534 ◽  
pp. 131-135
Author(s):  
You Yin ◽  
Rosalena Irma Alip ◽  
Yu Long Zhang ◽  
Ryota Kobayashi ◽  
Sumio Hosaka
Keyword(s):  
Phase Change ◽  
Active Medium ◽  
Low Cost ◽  
Single Layer ◽  
Dynamic Switching ◽  
Non Volatile Memory ◽  
Controlled Crystallization ◽  
Multi Level ◽  
Switching Characteristics ◽  
20 Nm

Here, we report multi-level storage (MLS) in multi-layer (ML) and single-layer (SL) phase change memories (PCM). For the former ML-PCM device, the active medium with two layers of chalcogenide consists of a top 30 nm TiN/180 nm SbTeN/20 nm TiN/bottom 120 nm SbTeN stacked multi-layer. Three stable and distinct resistance states are demonstrated in both static and dynamic switching characteristics of the multi-layer devices. For the latter SL-PCM device, the active medium with only one layer of chalcogenide consists of a top 50 nm TiN/150 nm SbTeN. We demonstrate that the number of distinguishable resistance levels can readily reach 16 and even higher. These levels in this study result from the initial threshold switching and the subsequent current-controlled crystallization induced by Joule heating. Therefore, the latter memory allows the creation of many distinct levels, thus enabling the low-cost ultra-high-density non-volatile memory.

Optical Monitoring and Numerical Simulation of Temperature Distribution at Selective Laser Melting of Ti6Al4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 474-481 ◽  
Author(s):  
Ivan Zhirnov ◽  
Ina Yadroitsava ◽  
Igor Yadroitsev
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Selective Laser Melting ◽  
Ti6al4v Alloy ◽  
Advanced Technology ◽  
Temperature Fields ◽  
Optical Monitoring ◽  
Metal Powders ◽  
Laser Melting ◽  
Ir Camera

Selective laser melting (SLM) is a modern method for producing objects with complex shape and fine structures in one working cycle from metal powders. Combination of the advanced technology of SLM with unique properties of Ti6Al4V alloy allows creating complex 3D objects for medicine or aerospace industry. Since properties of SLM parts depend on the geometrical characteristics of tracks and their cohesion, optical monitoring is actually used to for control the process. Temperature gradient determines the microstructure and mechanical properties of the SLM part, so studies about temperature fields are primarily important. On-line monitoring during laser scanning of Ti6Al4V alloy and formation of a single track in real-time with high-speed IR camera was studied. Numerical simulation allowed estimation the temperature distribution during processing. Conclusion regarding control system based on the online monitoring of deviations of the signal from IR camera during the SLM process was done.

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