Combinatorial Study of Zeolites in Catalyzing the Acylation of Benzene via Laser-Induced Fluorescence Imaging

2002 ◽  
Vol 56 (8) ◽  
pp. 1044-1047 ◽  
Author(s):  
Hui Su ◽  
Edward S. Yeung
Keyword(s):  
Fluorescence Imaging ◽  
High Throughput Screening ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Solid Catalyst ◽  
Mfi Zeolite ◽  
Gaseous Products ◽  
Beta Zeolites ◽  
Higher Temperature ◽  
A Charge

Laser-induced fluorescence imaging (LIFI) has been developed into a high-throughput screening (HTS) technique for heterogeneous catalysis. A laser beam is focused into a sheet parallel to the surface of the solid catalyst. Fluorescence from selected gaseous products formed immediately above the surface is imaged by a charge-coupled device (CCD) camera. Here, in situ LIFI was used to simultaneously screen the catalytic properties of a 15-member library consisting of mordenites (MOR), ferrierites (FER), ZSM-5 (MFI), zeolite γ-(gamma) (FAU), and beta zeolites (BEA) with various Si/Al ratios in the acylation of benzene with phthalic anhydride. Only beta zeolites were found to be active in this reaction over the temperature range of 190 to 340 °C. Substantial deactivation of beta zeolites was observed within less than one minute at higher temperature and the degree of deactivation varied with reaction temperature and the composition of the reactant mixture, as well as the Si/Al ratio of the beta zeolites. The deactivated beta zeolites can be regenerated partially by heating in a flow of oxygen. Up to 80% recovery of the catalytic activity was obtained. Similar recovery was observed after several deactivation–regeneration cycles.

Profiling of Redox Atmosphere in Flames by Chemical Seeding/Planar Laser-Induced Fluorescence (CS/PLIF)

2005 ◽  
Vol 128 (4) ◽  
pp. 765-772 ◽  
Author(s):  
K. Kitagawa ◽  
S. Itoh ◽  
N. Arai ◽  
Ashwani K. Gupta
Keyword(s):  
Rotational Temperature ◽  
Thermal Dissociation ◽  
Flame Temperature ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Charge Coupled Device ◽  
Planar Laser ◽  
A Charge ◽  
Local Value ◽  
Redox Index

Knowledge on the local value of reducing and oxidizing (redox) atmospheres in flames is among the most important issues to be desired by combustion engineers. In this study, the spatial distribution of a redox atmosphere in flames has been measured experimentally by the chemical seeding/laser-induced fluorescence (CS/LIF) technique. A solution of iron was sprayed into a premixed propane-air flame supported on a slot burner. The LIF intensity of FeO band was compared to that of a Fe line to estimate the experimentally determined degree of atomization in the reaction FeO→Fe+O. The flame temperature profile was determined as a rotational temperature and was obtained by comparing the LIF (laser-induced fluorescence) intensities of OH rotational lines. The degree of atomization was theoretically calculated on the basis that simple thermal dissociation takes place in the reaction. The redox atmosphere, or a redox index, is defined as the ratio of the experimentally determined to theoretically calculated degrees of atomization. Two-dimensional distributions or profiles of the excitation temperature, experimentally determined degree of atomization, and redox index have been measured using a charge coupled device (CCD) camera fitted with an optical bandpass filter and the associated signal processing using a computer. This method has been successfully applied to quantitatively illustrate the local atmosphere and profile of the redox atmosphere in flames.

Development of a bio-monitoring system for toxicants in water with fish

2001 ◽  
Vol 1 (2) ◽  
pp. 9-17
Author(s):  
Y.-H. Lee ◽  
H.-K. Lee ◽  
C.-H. Chang ◽  
W.-H. Kim
Keyword(s):  
Monitoring System ◽  
Treatment Plant ◽  
Ccd Camera ◽  
Water Treatment Plant ◽  
Abnormal Behavior ◽  
Time Interval ◽  
Toxic Substances ◽  
Bio Monitoring ◽  
Index Value ◽  
A Charge

A bio-monitoring system for toxicants in water has been developed and verified for actual applications. This system is based on the motionality of five Acheilognathus lanceolata, a fish known to be very sensitive to toxic substances, moving around in an aquarium. Their movements are continuously monitored with a charge coupled device (CCD) camera and analyzed to find and quantify any abnormal behavior in their motional characteristics in comparison with the pre-acquired data. That is, the images of fish captured by a CCD camera are digitalized to identify the location of fish in a constant time interval and the locations of each fish were then analyzed mathematically with a personal computer using the equations proposed to determine the motional characteristics such as floatness, fledness and mobility(agility). These data are then converted by means of fuzzy estimation to an index value, defined as the contamination index (CI), by which the system provides the information about the overall toxic strength of the toxicant in the water flowing into the aquarium. If the fish are exposed to toxicant(s), the CI value will be proportional to the strength of its toxicity. The pilot test was performed in a water treatment plant for six months in order to verify the reproducibility of the system over the unstable conditions such as highly turbid water after rainfall as well as in normal conditions. The test results revealed that this monitoring system has good reproducibility and sensitivity, proving our approach, described in this paper, is reliable. As a result, this approach seems to enable us to make a quick and easy detection of toxic substances contained in water, therefore, this system can be applied to a source of water supply as a toxicant watching system.

scholarly journals Pyrolysis and Oxidation of PAN in Dry Air. Thermoanalytical Methods

1970 ◽  
Vol 17 (1) ◽  
pp. 38-42
Author(s):  
Anna BIEDUNKIEWICZ ◽  
Pawel FIGIEL ◽  
Marta SABARA
Keyword(s):  
Temperature Increase ◽  
Heating Rates ◽  
Linear Change ◽  
Dry Air ◽  
Isothermal Conditions ◽  
Gaseous Products ◽  
Heterogeneous Processes ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Kinetics Of

The results of investigations on pyrolysis and oxidation of pure polyacrylonitrile (PAN) and its mixture with N,N-dimethylformamide (DMF) under non-isothermal conditions at linear change of samples temperature in time are presented. In each case process proceeded in different way. During pyrolysis of pure PAN the material containing mainly the product after PAN cyclization was obtained, while pyrolysis of PAN+DMF mixture gave the product after cyclization and stabilization. Under conditions of measurements, in both temperature ranges, series of gaseous products were formed.For the PAN-DMF system measurements at different samples heating rates were performed. The obtained results were in accordance with the kinetics of heterogeneous processes theory. The process rates in stages increased along with the temperature increase, and TG, DTG and HF function curves were shifted into higher temperature range. This means that the process of pyrolysis and oxidation of PAN in dry air can be carried out in a controlled way.http://dx.doi.org/10.5755/j01.ms.17.1.246

scholarly journals Spectroscopic flat-fields can be used for precision CCD gain and noise tests

2021 ◽  
Vol 38 ◽  
Author(s):  
J. Gordon Robertson
Keyword(s):  
Ccd Camera ◽  
Matched Pair ◽  
Optical Fibres ◽  
Charge Coupled Device ◽  
Small Areas ◽  
Flat Field ◽  
Basic Parameters ◽  
The Mean ◽  
A Charge ◽  
Analogue To Digital

Abstract One of the basic parameters of a charge coupled device (CCD) camera is its gain, that is, the number of detected electrons per output Analogue to Digital Unit (ADU). This is normally determined by finding the statistical variances from a series of flat-field exposures with nearly constant levels over substantial areas, and making use of the fact that photon (Poisson) noise has variance equal to the mean. However, when a CCD has been installed in a spectroscopic instrument fed by numerous optical fibres, or with an echelle format, it is no longer possible to obtain illumination that is constant over large areas. Instead of making do with selected small areas, it is shown here that the wide variation of signal level in a spectroscopic ‘flat-field’ can be used to obtain accurate values of the CCD gain, needing only a matched pair of exposures (that differ in their realisation of the noise). Once the gain is known, the CCD readout noise (in electrons) is easily found from a pair of bias frames. Spatial stability of the image in the two flat-fields is important, although correction of minor shifts is shown to be possible, at the expense of further analysis.

Laser-induced fluorescence imaging for studies of cultural heritage

2007 ◽  
Author(s):  
Rasmus Grönlund ◽  
Sune Svanberg ◽  
Jenny Hällström ◽  
Kerstin Barup ◽  
Giovanna Cecchi ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Fluorescence Imaging ◽  
Laser Induced Fluorescence

Comparison of Pressure Drop and Endwall Heat Transfer Measurements to Flow Visualization Testing of Solid and Porous Pin Fin Arrays

2009 ◽  
Author(s):  
Jared M. Pent ◽  
Jay S. Kapat ◽  
Mark Ricklick
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Visualization ◽  
Local Heat Transfer ◽  
Ccd Camera ◽  
Local Heat ◽  
Transfer Coefficients ◽  
Porous Aluminum ◽  
Pin Fins ◽  
A Charge

This paper examines the local and averaged endwall heat transfer effects of a staggered array of porous aluminum pin fins with a channel blockage ratio (blocked channel area divided by open channel area) of 50%. Two sets of pins were used with pore densities of 0 (solid) and 10 pores per inch (PPI). The pressure drop through the channel was also determined for several flow rates using each set of pins. Local heat transfer coefficients on the endwall were measured using Thermochromatic Liquid Crystal (TLC) sheets recorded with a charge-coupled device (CCD) camera. Static and total pressure measurements were taken at the entrance and exit of the test section to determine the overall pressure drop through the channel and explain the heat transfer trends through the channel. The heat transfer and pressure data was then compared to flow visualization tests that were run using a fog generator. Results are presented for the two sets of pins with Reynolds numbers between 25000 and 130000. Local HTC (heat transfer coefficient) profiles as well as spanwise and streamwise averaged HTC plots are displayed for both pin arrays. The thermal performance was calculated for each pin set and Reynolds number. All experiments were carried out in a channel with an X/D of 1.72, a Y/D of 2.0, and a Z/D of 1.72.

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