12 Rhenium(I) tricarbonyl complexes have been studied as possible luminescence-based pH probes. A dramatic change in luminescence intensity near pH 7 was observed for those species containing the hydroxypyridine ligand. The change in intensity was not accompanied by any significant change in excited state lifetime, indicating a static quenching mechanism. A bimolecular quenching study with phenol and phenolate ions indicates that an intramolecular quenching mechanism is responsible for the observed photophysical changes.

12 Laboratory and field results of the testing of a new, visible-range spectrometry utilizing the robust signals produced by Friedel-Crafts reaction compounds demonstrate the utility of a rapid, portable, and sensitive method of on-site analysis for petroleum substances in soil and water samples. Preliminary testing of the kits and spectrometer was performed at the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) in Hanover, NH. Specific field protocols for the sampling and handling of soils for gasoline range organics and diesel range organics were established for the field sampling, which was conducted at the U.S. Navy Facilities Engineering Service Center in Port Hueneme, CA. Co-located soil samples were collected and either split or homogenized for subsequent partitioning to provide samples for the on-site analysis by the field kit/spectrometer technology and for later analysis by off- site reference laboratories. Test kit colorimetric results are by visual and spectrometric methods, and are compared with reference laboratory results and CRREL analyses.

12 A new optical tool, which will help petrochemical refinery and chemical processing plant personnel locate the source of a toxic or hazardous gas leak while remaining outside the perimeter of the processing area, has been demonstrated. This sensor is capable of locating leaks from a distance of about 20 m, with a response time of less than 1 second. By enhancing the speed with which leaks can be located, the risk of an incipient failure becoming a catastrophic failure is reduced significantly. The tool is based on Tunable Diode Laser Absorption Spectroscopy (TDLAS). TDLAS is currently being utilized in these industrial environments in permanently-installed open-path configurations to sense releases of selected gases as they exit the processing area. The sensor described here combines a lightweight, portable optical transceiver with battery-operated electronics in a single hand-held package. By standing in a safe area and `shining' the eye-safe laser beam emanating from this device onto suspected leak sources, operators may rapidly isolate the source while minimizing their potential exposure to the hazard. The sensor can be configured to sense leaks resulting in path-integrated concentrations of, for example, 2 ppm-m of hydrogen fluoride, 200 ppm-m of hydrogen sulfide, or 10 ppm-m of methane.

12 Gaseous photo-induced oxidations of a variety of organic compounds by titanium dioxide (TiO₂) have been studied extensively in the literature. The response of the organic to photochemical reactions with TiO₂ and the extent of organic oxidation are typically measured by monitoring the initial concentration of organic and the oxidation by- products using gas chromatography. In this study, TiO₂ sensors are produced by coating and drying films of Degussa P25 TiO₂ onto Al₂O₃ substrates. Tests are conducted at ambient temperatures in a controlled atmospheric cell. Electrical responses from the TiO₂ sensors are monitored as the sensors are exposed to a variety of organic compounds in the presence of ultraviolet light. Unique voltammetric `signatures' are obtained from the sensors as they react with specific gaseous organics. These signatures can be used to distinguish and identify gaseous constituents.

12 Membranes play an important role in the wastewater and drinking water processing. Membrane processes are increasingly finding role in sensor and monitoring system design. The challenges facing the designing of such analytical systems and those of the conventional membrane processes have several similarities. In this presentation fundamentals of membrane technology, current trends and future possibilities pertinent to water industry are discussed.

12 In recent years, we have developed the eco-sensor, which means the sensor for the measurement of environmental pollutants, based on lipid membranes for continuous monitoring of underground water in industry areas such as semiconductor factories. In order to improve the stability and the responsibility of bilayer lipid membranes (BLMs) in the eco-sensor, we have investigated both the stabilization of BLMs based on the supporting structure and the test making of the automatic BLMs preparation device. The application of the supporting structure using gelatin, etc showed the some times' extension of the BLMs life. But the decrease in the sensitivity of the sensor was observed in the storage of the sensor. An automatic BLMs preparation device was made by use of an inkjet mechanism. The reproducibility of the BLMs preparation was remarkably improved. The sensitivity to organochlorine compounds was in the order of 10 ppb using the monoolein BLMs.

12 By incorporating a new electrochemical detector based on potential gradient detection, a portable capillary electrophoresis (CE) instrument for field analysis has been developed. The portable CE instrument can be used for detecting a broad range of ionizable species in aqueous solutions. The detection limits of the instrument for most ions were around 0.1 ppm with a linear range of three orders of magnitude. Ions in mineral water (K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^-, NO₃^-, SO₄^2-, CO₃^2-) and bromate in drinking water were analyzed as examples with the portable capillary electrophoresis instrument.

12 Energetical and spectral characteristics of backward stimulated Raman scattering (BSRS) in water and water solutions of organic liquids (acetone, benzene, ethanol, cyclohexane) at different excitation conditions have been experimentally investigated. Maximum conversion efficiency of laser light into BSRS wave was about 40%. For picosecond range experimental results and calculations are presented showing the BSRS intensity as a function of the main experimental parameters concerning the geometry of excitation and the exciting intensity. Thus it's possible to forecast the best experimental set-up in term of BSRS efficiencies and to estimate the minimum length of water necessary to detect BSRS. Competition with other scatterings is observed. In nanosecond range simultaneously with BSRS stimulated Brillouin scattering has been excited. Possible applications are discussed.

12 Over the past few years, INO has developed an Industrial Fiber Lidar (IFL). It enables the particulate pollution monitoring on industrial sites. More particularly, it has been used to take measurements of particulate concentration at Port Facilities of an aluminum plant during boat unloading. It is an eye-safe and portable lidar. It uses a fiber laser also developed at INO emitting 1.7 microJoules at 1534 nm with a pulse repetition frequency of 5 kHz. Given the harsh environment of an industrial site, all the sensitive equipment like the laser source, detector, computer and acquisition electronics are located in a building and connected to the optical module, placed outside, via optical fibers up to 500 m long. The fiber link also offers all the flexibility for placing the optical module at a proper location. The optical module is mounted on a two axis scanning platform, able to perform an azimuth scan of 0 to 355 deg and an elevation scan of +/- 90 deg, which enables the scanning of zones defined by the user. On this industrial site, materials like bauxite, alumina, spathfluor and calcined coke having mass extinction coefficients ranging from 0.53 to 2.7 m²/g can be detected. Data for different measurement configurations have been obtained. Concentration values have been calculated for measurements in a hopper, along a wharf and over the urban area close to the port facilities. The lidar measurements have been compared to high volume samplers. Based on these comparisons, it has been established that the IFL is able to monitor the relative fluctuations of dust concentrations. It can be integrated to the process control of the industrial site for alarm generation when concentrations are above threshold.

12 Optical spectroscopy related to analytical techniques have attracted much interest in recent years and became a central part of versatile instruments used for trace gas monitoring. Optical methods are based on different interactions between radiation and matter (absorption, emission and scattering) and use different sources of radiation such as conventional lamps, lasers, the sun, etc. Differential Optical Absorption Spectroscopy is a good example of these kind of techniques where commercial instruments are available today. Typically, it consists of a collimated broadband radiation source that shines a beam of light through an open atmospheric path several hundred meters long; at the other end, a receiving telescope is located which focus the beam on a medium resolution spectrometer-photodetector system that analyzes the wavelength spectrum of the incoming light within a certain range. The absorption bands of a specific gas component failing in this range are thus detected. For multicomponent analysis, the spectrometer must be scanned across different wavelength ranges introducing potential error sources.

12 Recent advances in mid-IR semiconductor laser technology based on intersubband transitions in InGaAs quantum wells promise a dramatic impact on tunable diode laser-based sensors for trace gases. This paper reports recent progress toward this realization of room-temperature laser-based sensors for combustion-generated pollutants such as NO_x and SO_x. Laboratory measurements of SO₂ at 8.6 micrometers are presented with detection limits on the order of 1 ppm. Extensions of these approaches for higher sensitivity measurements in exhaust gas conditions are described, as well as measurements of SO₃.

12 This paper reports the results of ammonia measurements near two CAFOs. In September of 1999, measurements were conducted for 48 hours downwind of a large-scale CAFO using two open- path monitors; an ultra violet differential optical absorption spectrometer (UV DOAS), and a Fourier transform interferometer (FTIR). In March of 2000, measurements were conducted at a much smaller CAFO using UV DOAS. This paper describes the calibration of a UV DOAS, compares UV DOAS and FTIR measurements, describes the effects of wind and atmospheric stability on ambient ammonia concentration, and suggests potential applications for open-path monitors for assessing public health risk.

12 A novel multivariate visible/NIR optical computing approach applicable to standoff sensing will be demonstrated with porphyrin mixtures as examples. The ultimate goal is to develop environmental or counter-terrorism sensors for chemicals such as organophosphorus (OP) pesticides or chemical warfare simulants in the near infrared spectral region. The mathematical operation that characterizes prediction of properties via regression from optical spectra is a calculation of inner products between the spectrum and the pre-determined regression vector. The result is scaled appropriately and offset to correspond to the basis from which the regression vector is derived. The process involves collecting spectroscopic data and synthesizing a multivariate vector using a pattern recognition method. Then, an interference coating is designed that reproduces the pattern of the multivariate vector in its transmission or reflection spectrum, and appropriate interference filters are fabricated. High and low refractive index materials such as Nb₂O₅ and SiO₂ are excellent choices for the visible and near infrared regions. The proof of concept has now been established for this system in the visible and will later be extended to chemicals such as OP compounds in the near and mid-infrared.

12 The Synchronous Scanning Luminoscope (SSL) is a field- portable, synchronous luminescence spectrofluorometer that was developed for on-site analysis of contaminated soil and ground water. The SSL is capable of quantitative analysis of total polynuclear aromatic hydrocarbons (PAHs) using phosphorescence and fluorescence techniques with a high correlation to laboratory data as illustrated by this study. The SSL is also capable of generating benzo(a)pyrene equivalency results, based on seven carcinogenic PAHs and Navy risk numbers, with a high correlation to laboratory data as illustrated by this study. These techniques allow rapid field assessments of total PAHs and benzo(a)pyrene equivalent concentrations. The Luminoscope is capable of detecting total PAHs to the parts per billion range. This paper describes standard field methods for using the SSL and describes the results of field/laboratory testing of PAHs. SSL results from two different hazardous waste sites are discussed.

12 A compact and portable laser-based sensor has been developed for absolute measurements of CO₂ concentration with high precision and accuracy, in air samples at atmospheric pressure. a DFB diode laser, operating near 2 micrometers at room temperature, was used. It was tuned into resonance with the R(34) line of the v₁ + 2v₂ degree(s) + v₃ combination band. The laser beam was fiber-coupled in order to allow remote operation. Severe tests of the spectrometer were done using certified air mixtures, with the aim to determine its performance. Applications to atmospheric monitoring were discussed. Particularly, the suitability of our spectrometer for measuring soil CO₂ efflux was demonstrated.

12 Norway spruce [Picea abies (L.) Karst.] needles represent a very useful bioindicator of the air pollution. They serve not only as natural samplers of the pollutants but micromorphology of the epistomatal area can be directly correlated with an environmental stress. The needles of trees growing in polluted areas exhibit different types of injury to the epicuticular wax layer. It is evident that these changes of the morphology of the wax layers are connected also with the changes of their chemical composition and so a potential of the FT Raman spectroscopy was tested to serve as a screening method of these changes. In this work variability of the spectra with the age and with the position in the tree, in the locality, and also in the different localities of the Czech Republic was studied and evaluated in comparison with results of electron scanning microscopy.

12 The difficulty of a atmosphere mix monitoring problem from flying apparatus consists in a small level of scattered light from an earthly surface. With increase of height of flight the level of light exposure of the photoreceiver device decreases under the square-law. In particular it is essential for spectral monitoring in the IR range, where there are no high-sensitivity photoreceivers. Just it creates restrictions for lidars application at impurity gases monitoring in atmosphere. Such restriction is not present at solar spectrometers, as with increase of height of flight is increased and area of an observable earthly surface. In the report it's brought the description of solar spectrometer for research of methane in a near-earth layer of atmosphere. The entrance part of the device consists from interference light filter, scanned Fabry-Perot interferometer and focusing lens. The research carry out on 1666 nm wavelength. As the photoreceiver is used cooled the germanium photo diode. In spite of the fact that the device works on group rather poorly absorbing transitions of methane, as against transitions close 3300 - 3400 nm, the higher sensitivity is provided at the expense of application of the more sensitive photoreceiver. Thus, the sensitivity of the device reaches 16 ppm*m, that allows to determine methane concentration at a level 0.1 ppm.

12 According to users of remote optical instruments for measuring process emissions or air quality, they don't work well enough to justify their use for demonstrating compliance with statutory limits. According to instrument manufacturers, the users don't appreciate their instruments or the performance capabilities and are certainly not prepared to pay enough for the kind of validation they are demanding. One thing is clear; everyone wants proven performance. In this paper we examine the determination of critical performance factors for remote optical measurement techniques within the context of future European standardization legislation.

12 We report for the first time, the development of a 3D optical random access memory material for neutron dosimetry. Detection of energetic neutrons is important in many applications, spanning from radioactive waste monitoring to space exploration. These anthracene-based photochromic dosimeters show a decrease in fluorescence intensity following exposure to energetic neutrons. Unlike current neutron dosimeters, where foreknowledge of the neutron energy is necessary to determine an exposure dose, these materials can be used in unknown environments (e.g. space exploration). A readout system has also been developed to determine the radiation characteristics (e.g. neutron energy) necessary for estimating dose. The results presented in this work, demonstrate the potential of these novel materials for space exploration and other applications where foreknowledge of neutron energy is unknown and current dosimeters are incapable of providing accurate dose information.

12 In this work, we present the fluorescence spectra of anthracene and pyrene vapors at different elevated temperatures (from 150 to 650 degree(s)C) excited with the 337 nm line of a nitrogen laser. We describe the high temperature effects on the resulting spectral properties including spectral intensity, spectral bandwidth and spectral shift. We found that the PAH fluorescence spectral bandwidths become very broad as the temperature increases. The broadening is mainly due to thermal vibrational sequence congestion. We also have found that the fluorescence intensity of pyrene vapor increases with increasing temperature, which results from the increase of the pyrene vapor absorption cross section at 337 nm.