Computer Control of the Spectral Composition of the Powerful Laser System Irradiation with a Wide Range of Laser Transitions on Metal Vapors

Abstract. We describe the design and testing of a flexible bag ("Lung") accumulator attached to a gas chromatographic (GC) analyzer capable of measuring surface-atmosphere greenhouse gas exchange fluxes in a wide range of environmental/agricultural settings. In the design presented here, the Lung can collect up to three gas samples concurrently, each accumulated into a Tedlar bag over a period of 20 min or longer. Toggling collection between 2 sets of 3 bags enables quasi-continuous collection with sequential analysis and discarding of sample residues. The Lung thus provides a flexible "front end" collection system for interfacing to a GC or alternative analyzer and has been used in 2 main types of application. Firstly, it has been applied to micrometeorological assessment of paddock-scale N2O fluxes, discussed here. Secondly, it has been used for the automation of concurrent emission assessment from three sheep housed in metabolic crates with gas tracer addition and sampling multiplexed to a single GC. The Lung allows the same GC equipment used in laboratory discrete sample analysis to be deployed for continuous field measurement. Continuity of measurement enables spatially-averaged N2O fluxes in particular to be determined with greater accuracy, given the highly heterogeneous and episodic nature of N2O emissions. We present a detailed evaluation of the micrometeorological flux estimation alongside an independent tuneable diode laser system, reporting excellent agreement between flux estimates based on downwind vertical concentration differences. Whilst the current design is based around triplet bag sets, the basic design could be scaled up to a larger number of inlets or bags and less frequent analysis (longer accumulation times) where a greater number of sampling points are required.

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A Model for Deposition of Metal Vapors From Multiple Targets on a Cylindrical Substrate

Volume 14: Processing and Engineering Applications of Novel Materials ◽

10.1115/imece2009-10637 ◽

2009 ◽

Author(s):

Lakshmi Singh ◽

Anil K. Kulkarni ◽

Jogender Singh

Keyword(s):

Physical Vapor Deposition ◽

Ceramic Composite ◽

Relative Concentration ◽

Functionally Graded ◽

Multiple Targets ◽

Functionally Graded Composite ◽

Metal Vapors ◽

Wide Range ◽

Materials Used ◽

Process Prediction

The paper addresses a challenging problem of developing technology for heat exchanger tubes embedded in ceramic composite matrix. Functionally graded composite tubes, made using physical vapor deposition (PVD) process, are required to have diffusion barrier layers, withstand high temperature, and be impermeable to hydrogen. The work addresses mathematical modeling of the deposition of metallic vapors from multiple targets on a cylindrical substrate to simulate the PVD process in manufacturing such tubes. Materials used for the deposition are Molybdenum and Niobium because they have shown good formability, strength, toughness and ductility over a wide range of temperatures. Commercially available software FLUENT was used to model the process. Prediction of condensation of vapors from metal ingots occurs in varying proportion along the circumference of the tube, resulting in submicron layers of different materials of varying thicknesses being ingrained into each other. Results are presented for patterns of materials showing continuously changing relative concentration of deposited metals over a stationary and rotating cylindrical substrate.

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KrF laser system with a wide range of wavelength tuning

10.1117/12.879644 ◽

2010 ◽

Cited By ~ 1

Author(s):

Yu. Panchenko ◽

V. Dudarev ◽

I. Konovalov ◽

V. Losev ◽

A. Pavlinsky ◽

...

Keyword(s):

Laser System ◽

Wavelength Tuning ◽

Wide Range ◽

Krf Laser

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Ex-Vivo Exposure on Biological Tissues in the 2-μm Spectral Range with an All-Fiber Continuous-Wave Holmium Laser

Photonics ◽

10.3390/photonics9010020 ◽

2021 ◽

Vol 9 (1) ◽

pp. 20

Author(s):

Mariya S. Kopyeva ◽

Serafima A. Filatova ◽

Vladimir A. Kamynin ◽

Anton I. Trikshev ◽

Elizaveta I. Kozlikina ◽

...

Keyword(s):

Solid State ◽

Soft Tissues ◽

Continuous Wave ◽

Ex Vivo ◽

Laser System ◽

Biological Tissues ◽

Holmium Laser ◽

Experimental Point ◽

Ablation Efficiency ◽

Wide Range

We present the results on the interaction of an all-fiber Holmium-doped laser CW radiation at a wavelength of 2100 nm with soft tissues and compare it with the other results obtained by the most used solid-state laser systems. Ex-vivo single spot experiments were carried out on the porcine longissimus muscles by varying the laser impact parameters in a wide range (average output power 0.3, 0.5 and 1.1 W; exposure time 5, 30 and 60 s). Evaluation of the laser radiation exposure was carried out by the size of coagulation and ablation zones on the morphological study. Exposure to a power of 0.3 W (1.5–18 J of applied energy) caused only reversible changes in the tissues. The highest applied energy of 66 J for 1.1 W and a 60-s exposure resulted in a maximum ablation depth of approximately 1.2 mm, with an ablation efficiency of 35%. We have shown that it is not necessary to use high powers of CW radiation, such as 5–10 W in the solid-state systems to provide the destructive effects. Similar results can be achieved at lower powers using the simple all-fiber Holmium laser based on the standard single-mode fiber, which could provide higher power densities and be more convenient to manufacture and use. The obtained results may be valuable as an additional experimental point in the field of existing results, which in the future will allow one to create a simple optimal laser system for medical purposes.

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Near-IR imaging microscopy using an acousto-optic tunable filter (AOTF)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100132297 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1532-1533

Author(s):

Patrick J. Treado ◽

Ira W. Levin ◽

E. Neil Lewis

Keyword(s):

Near Infrared ◽

Computer Control ◽

Image Data ◽

Tunable Filter ◽

Data Set ◽

Array Detectors ◽

Halogen Light ◽

Wide Range ◽

Acousto Optic Device ◽

Halogen Light Source

Near-infrared spectroscopy is a sensitive and non-invasive probe for chemical analyses. The integration of spectroscopic and imaging technologies is a potent tool for the study of a wide range of biological materials.Continuously tunable acousto-optic filters operable in the ultraviolet, visible and infrared are now widely available. These computer controlled notch filters provide random wavelength access, wide spectral coverage and moderate spectral resolution. AOTFs potentially have a wide range of spectroscopic applications. We employ AOTF technology for visible/NIR absorption microscopy between 600-2000 nm.The microscope is constructed around an acousto-optic device coupled to an infinity corrected microscope employing either silicon or indium antinomide focal-plane array detectors. In operation, the AOTF is used to spectrally filter a quartz halogen light source. Under computer control the AOTF is swept through a wavelength range and at predetermined intervals images are recorded. Hundreds of frames may be collected, and the spectral image data set can readily comprise many megabytes of data.

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Efficiency of ablative plasma energy transfer into a massive aluminum target using different atomic number ablators

Laser and Particle Beams ◽

10.1017/s0263034615000452 ◽

2015 ◽

Vol 33 (3) ◽

pp. 379-386 ◽

Cited By ~ 2

Author(s):

A. Kasperczuk ◽

T. Pisarczyk ◽

T. Chodukowski ◽

Z. Kalinowska ◽

W. Stepniewski ◽

...

Keyword(s):

Energy Transfer ◽

Atomic Number ◽

Radiation Transport ◽

Laser System ◽

Plasma Stream ◽

Near Surface ◽

Aluminum Target ◽

X Ray ◽

Plasma Energy ◽

Wide Range

AbstractThis paper aims at investigation of efficiency of an ablative plasma energy transfer into a massive aluminum target using different atomic number ablators. For this reason, several target materials representing a wide range of atomic numbers (Z = 3.5–73) were used. The experiment was carried out at the iodine Prague Asterix Laser System. The laser provided a 250 ps pulse with energy of 130 J at the third harmonic frequency (λ3 = 0.438 μm). To study the plasma stream configurations a four-frame X-ray pinhole camera was used. The electron temperature of the plasma in the near-surface target region was measured by means of an X-ray spectroscopy. The efficiency of the plasma energy transport to the target was determined via the crater volume measurement using the crater replica technique. The experimental results were compared with two-dimensional numerical simulations where the plasma dynamics was based on the one-fluid, two temperature model, including radiation transport in diffusive approximation and ionization kinetics. It was shown that the plasma expansion geometry plays an important role in the ablative plasma energy transfer into the target.

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Low-cost photoacoustic imaging systems based on laser diode and light-emitting diode excitation

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545817300038 ◽

2017 ◽

Vol 10 (04) ◽

pp. 1730003 ◽

Cited By ~ 15

Author(s):

Qingkai Yao ◽

Yu Ding ◽

Guodong Liu ◽

Lvming Zeng

Keyword(s):

Laser Diode ◽

Near Infrared ◽

Photoacoustic Imaging ◽

Light Emitting Diode ◽

Imaging Modality ◽

Low Cost ◽

Laser System ◽

Great Promise ◽

Light Emitting ◽

Wide Range

Photoacoustic imaging, an emerging biomedical imaging modality, holds great promise for preclinical and clinical researches. It combines the high optical contrast and high ultrasound resolution by converting laser excitation into ultrasonic emission. In order to generate photoacoustic signal efficiently, bulky Q-switched solid-state laser systems are most commonly used as excitation sources and hence limit its commercialization. As an alternative, the miniaturized semiconductor laser system has the advantages of being inexpensive, compact, and robust, which makes a significant effect on production-forming design. It is also desirable to obtain a wavelength in a wide range from visible to near-infrared spectrum for multispectral applications. Focussing on practical aspect, this paper reviews the state-of-the-art developments of low-cost photoacoustic system with laser diode and light-emitting diode excitation source and highlights a few representative installations in the past decade.

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Powder Processing of Functionally Gradient Materials

MRS Bulletin ◽

10.1557/s0883769400048892 ◽

1995 ◽

Vol 20 (1) ◽

pp. 32-34 ◽

Cited By ~ 52

Author(s):

R. Watanabe

Keyword(s):

Laser Beam ◽

Stress Reduction ◽

Powder Processing ◽

Spray Deposition ◽

Computer Control ◽

Hot Isostatic Pressing ◽

Composition Profile ◽

Mixed Powder ◽

Process Innovations ◽

Wide Range

Powder metallurgical (P/M) processing of FGMs provides a wide range of compositional and microstructural control, along with shape-forming capability. Oxide/metal systems are desirable because this materials combination can be used to easily tailor materials properties. However, there are many problems to be investigated which pertain to each of the processing steps; process innovations will often be required to realize the versatility of this route. In this article, I briefly review the present status of the powder-processing method.Powder metallurgical fabrication of FGMs involves the following sequential steps with a selected material combination of metals and ceramics: determination of the optimum composition profile for an effective thermal-stress reduction; stepwise or continuous stacking of powder premixes according to the predesigned composition profile; compaction of the stacked powder heap and sintering with or without pressurizing. Besides the conventional powder metallurgical routes, a spray deposition method, using mixed powder suspensions and a slurry stacking method, have been developed to form continuously graded stacking. A powder spray stacking apparatus has been devised, which is fully automatic with computer control. Deposited compacts were cold isostatically pressed (CIP) and consolidated by hot isostatic pressing. Their microstructures show that this process provides fine compositional control with desired profiles.Differential temperature sintering by laser-beam heating has been studied to add versatility to the P/M process. The surface of the green compacts is scanned with a laser beam using a predesigned scanning pattern to ensure homogeneous heating over the entire surface.

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3D DRUG PRINTING- A SWING FROM LABORATORY PRODUCTION TO COMPUTERIZED PRODUCTION

Journal of Drug Delivery and Therapeutics ◽

10.22270/jddt.v9i5-s.3255 ◽

2019 ◽

Vol 9 (5-s) ◽

pp. 201-207

Author(s):

Asif Mohd Itoo ◽

Syed Naiem Raza ◽

Ahmar Khan ◽

Bashir Sarjohn ◽

Tariq Ubaid ◽

...

Keyword(s):

3D Printing ◽

Computer Control ◽

Three Dimensional ◽

Pharmacy Practice ◽

Therapeutic Index ◽

Point Of View ◽

Important Benefit ◽

Wide Range ◽

Drug Delivery Devices ◽

Complex Drug

Three-Dimensional (3D) printing is a process where objects are made in successive layers under computer control by fusing or depositing materials. The objects can be of nearly any shape or geometry and come in a computer-aided (CAD) design from 3D model. Since 3D printing began in 1984, it has changed enormously and has been used in a wide range of fields, including medicine and architecture. 3D printing moves rapidly and in future will transform and change the way we live and work from laboratory-based organs to pharmaceutical supplies. 3D printing in pharmaceuticals has been used to produce many novel dosage forms like microcapsules, complex drug-release profiles, nanosuspensions, and multilayered drug delivery devices. It also offers important advantages from the industrial point of view such as cost-efficiency, higher productivity, democracy-making and enhanced cooperation. Keeping in view the recent approval given by USFDA to many drug the focus has now shifted to the personalized medicine as it offers an important benefit to patients who need medications that have narrow therapeutic index or a higher predilection to be influenced by genetic polymorphisms. 3D printer is now seen as a valuable, efficient and economical tool to manufacture individualized medications, tailored to specific patients based on their needs and thereby change the future of pharmacy practice in general and pharmaceutical care in particular.

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Problems of using computer control of vermicular graphite in the microstructure of cast iron

10.30987/graphicon-2019-1-260-264 ◽

2019 ◽

Author(s):

Ирина Шаехова ◽

Irina Shaehova ◽

Алексей Панов ◽

Aleksey Panov ◽

Надежда Дегтярёва ◽

...

Keyword(s):

Materials Science ◽

Computer Control ◽

Automatic Identification ◽

Calculation Error ◽

Compacted Graphite Iron ◽

Graphite Inclusion ◽

Automatic Calculation ◽

Compacted Graphite ◽

Wide Range ◽

Necessary Truth

In recent decades, there has been an increase in industrial interest in compacted graphite iron, which has a very wide range of properties more depended on the graphite form. The same time, to date, there are no methods for controlling graphite in the microstructure of CGI necessary truth. In the present work, the automatic calculation error of the fraction of vermicular graphite is estimated, which is associated with the automatic identification error of the type of graphite inclusion. It is shown that automatic calculation without the metallographist increases accuracy in comparison with GOST 3443-87, but its error remains not acceptably high for materials science tasks and requires further improvement.

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