Upgrading a High Performance Spectrophotometer

1996 ◽  
Vol 4 (1) ◽  
pp. 39-46 ◽  
Author(s):  
David R. Massie ◽  
Stephen R. Delwiche
Keyword(s):  
High Performance ◽  
Near Infrared ◽  
Measurement Techniques ◽  
Optical Filters ◽  
Fast Response ◽  
Agricultural Products ◽  
System Response ◽  
Electromagnetic Spectrum ◽  
Analog To Digital ◽  
Single Beam

A spectrophotometer system was updated with a new computer and control circuitry to measure qualitative and quantitative characteristics of agricultural products between the ultraviolet and near infrared (NIR) regions of the electromagnetic spectrum. This single beam instrument, along with its computer, has a wavelength repeatability of 0.005 nm. This performance is required for proper system response compensation in a single beam system. Analog electronics are kept to a minimum by early conversion of the signal with a 10-μs 16-bit analog-to-digital (A/D) converter. A fast response real-time computer is required to service the A/D, wavelength drive and optical chopper. Herein, the development and selection of computer interfaces, data collection techniques and performance characteristics of this laboratory spectrophotometer system are described. The system is regularly used as the development tool in investigating new measurement techniques on agricultural products. It is also used to evaluate optical filters and other spectrophotometric systems.

High-performance near-infrared photodetectors based on C3N quantum dots integrated with single-crystal graphene

2021 ◽  
Author(s):  
Yun Zhao ◽  
Xiaoqiang Feng ◽  
Menghan Zhao ◽  
Xiaohu Zheng ◽  
Zhiduo Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electric Field ◽  
Single Crystal ◽  
High Performance ◽  
Near Infrared ◽  
Fast Response ◽  
Local Electric Field ◽  
Infrared Photodetectors ◽  
Photocurrent Response

Employing C3N QD-integrated single-crystal graphene, photodetectors exhibited a distinct photocurrent response at 1550 nm. The photocurrent map revealed that the fast response derive from C3N QDs that enhanced the local electric field near graphene.

scholarly journals Investigating the impact of in-vehicle transients on diesel soot emissions

2008 ◽  
Vol 12 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Zoran Filipi ◽  
Jonathan Hagena ◽  
Hosam Fathy
Keyword(s):  
High Performance ◽  
Fast Response ◽  
Test Cell ◽  
System Response ◽  
Particulate Emission ◽  
Power Train ◽  
The Real ◽  
Vehicle System ◽  
Soot Emissions ◽  
The Impact

This paper describes development of a test cell setup for concurrent running of a real engine and a simulation of the vehicle system, and its use for investigating highly-dynamic engine-in-vehicle operation and its effect on diesel engine emissions. Running an engine in the test cell under conditions experienced in the vehicle enables acquiring detailed insight into dynamic interactions between power train sub-systems, and the impact of it on fuel consumption and transient emissions. This type of data may otherwise be difficult and extremely costly to obtain from a vehicle prototype test. In particular, engine system response during critical transients and the effect of transient excursions on emissions are investigated using advanced, fast-response test instrumentation and emissions analyzers. Main enablers of the work include the highly dynamic AC electric dynamometer with the accompanying computerized control system and the computationally efficient simulation of the driveline/vehicle system. The latter is developed through systematic energy-based proper modeling that tailors the virtual model to capture critical powertrain transients while running in real time. Coupling the real engine with the virtual driveline/vehicle offers a chance to easily modify vehicle parameters, and even study different power train configurations. In particular, the paper describes the engine-in-the-loop study of a V-8, 6l engine coupled to a virtual 4?4 off road vehicle. This engine is considered as a high-performance option for this truck and the real prototype of the complete vehicle does not exist yet. The results shed light on critical transients in a conventional powertrain and their effect on NOx and soot emissions. Measurements demonstrate very large spikes of particulate concentration at the initiation of vehicle acceleration events. Characterization of transients and their effect on particulate emission provides a basis for devising engine-level or vehicle level strategies, and direct guidance for developing drive-by-wire systems and/or hybrid supervisory control.

scholarly journals A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

2020 ◽  
Vol 11 ◽  
pp. 1623-1630
Author(s):  
Liang Chen ◽  
Jianqi Dong ◽  
Miao He ◽  
Xingfu Wang
Keyword(s):  
Optical Sensor ◽  
High Performance ◽  
Near Infrared ◽  
Low Cost ◽  
Short Circuit ◽  
Fast Response ◽  
Zno Nanowire ◽  
Working Mechanism ◽  
Full Spectrum ◽  
Self Powered

In this work, a new type of self-powered, high-performance ultra-thin p-Si/n-ZnO nanowire (NW) flexible photodetector (PD) and its application as full-spectrum optical sensor and pyroelectric nanogenerator (PENG) are demonstrated. The working mechanism of PDs for PENGs is carefully investigated and systematically analyzed. The self-powered PDs exhibit high responsivity (1200 mA/W), high detectivity (1013 Jones) and fast response (τr = 18 μs, τf = 25 μs) under UV illumination. High and stable short-circuit output currents at each wavelength from ultraviolet (UV) to near-infrared (NIR) demonstrates that the device can realize full-spectrum optical communication. An experiment in which the PENG powers other devices is designed to further demonstrate the proposed working mechanism. This work provides an effective approach to realize self-powered, high-performance PDs for full-spectrum communication. Also, the fabrication of the PENG utilizing a simple and low-cost method shows its potential applications in self-powered flexible electronic devices.

A room-temperature near-infrared photodetector based on a MoS2/CdTe p–n heterojunction with a broadband response up to 1700 nm

2018 ◽  
Vol 6 (18) ◽  
pp. 4861-4865 ◽  
Author(s):  
Yuange Wang ◽  
Xiaowen Huang ◽  
Di Wu ◽  
Ranran Zhuo ◽  
Enping Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Near Infrared ◽  
Response Speed ◽  
Fast Response ◽  
Infrared Photodetectors ◽  
Infrared Photodetector ◽  
High Responsivity ◽  
Specific Detectivity

High-performance room-temperature infrared photodetectors based on MoS2/CdTe p–n heterojunction with broadband response, high responsivity, specific detectivity as well as fast response speed were demonstrated.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

About Measures of the State Support for Technical Equipment of Agricultural Producers

2020 ◽  
pp. 20-27
Author(s):  
A.Ya. Kibirov ◽  
Keyword(s):  
Statistical Analysis ◽  
Energy Saving ◽  
High Performance ◽  
The State ◽  
Agricultural Products ◽  
Technical Equipment ◽  
Agricultural Machinery ◽  
State Support ◽  
Agricultural Producers ◽  
Technical Base

The article uses methods of statistical analysis, deduction and analogy to consider programs at the Federal, regional and economic levels, which provide for measures aimed at improving the technical equipment of agricultural producers. Particular attention is paid to the acquisition of energy-saving, high-performance agricultural machinery and equipment used in the production and processing of agricultural products. An assessment of the effectiveness of state support for updating the material and technical base of agriculture is given. Based on the results of the study, conclusions and recommendations were formulated.

scholarly journals Dual-Cation Electrolytes Crosslinked with MXene for High-Performance Electrochromic Devices

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 874
Author(s):  
Soyoung Bae ◽  
Youngno Kim ◽  
Jeong Min Kim ◽  
Jung Hyun Kim
Keyword(s):  
Ionic Conductivity ◽  
Response Time ◽  
Indium Tin Oxide ◽  
High Performance ◽  
Fast Response ◽  
High Ionic Conductivity ◽  
Electrochromic Device ◽  
Fast Response Time ◽  
Coloration Efficiency ◽  
Conduction Pathway

MXene, a 2D material, is used as a filler to manufacture polymer electrolytes with high ionic conductivity because of its unique sheet shape, large specific surface area and high aspect ratio. Because MXene has numerous -OH groups on its surface, it can cause dehydration and condensation reactions with poly(4-styrenesulfonic acid) (PSSA) and consequently create pathways for the conduction of cations. The movement of Grotthuss-type hydrogen ions along the cation-conduction pathway is promoted and a high ionic conductivity can be obtained. In addition, when electrolytes composed of a conventional acid or metal salt alone is applied to an electrochromic device (ECD), it does not bring out fast response time, high coloration efficiency and transmittance contrast simultaneously. Therefore, dual-cation electrolytes are designed for high-performance ECDs. Bis(trifluoromethylsulfonyl)amine lithium salt (LiTFSI) was used as a source of lithium ions and PSSA crosslinked with MXene was used as a source of protons. Dual-Cation electrolytes crosslinked with MXene was applied to an indium tin oxide-free, all-solution-processable ECD. The effect of applying the electrolyte to the device was verified in terms of response time, coloration efficiency and transmittance contrast. The ECD with a size of 5 × 5 cm2 showed a high transmittance contrast of 66.7%, fast response time (8 s/15 s) and high coloration efficiency of 340.6 cm2/C.

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