Spectroscopic chemical analysis methods and apparatus

Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted simultaneously with native fluorescence spectroscopy to provide high levels of sensitivity and specificity in the same instrument

Electron beam pumped semiconductor laser

Electron-beam-pumped semiconductor ultra-violet optical sources (ESUVOSs) are disclosed that use ballistic electron pumped wide bandgap semiconductor materials. The sources may produce incoherent radiation and take the form of electron-beam-pumped light emitting triodes (ELETs). The sources may produce coherent radiation and take the form of electron-beam-pumped laser triodes (ELTs). The ELTs may take the form of electron-beam-pumped vertical cavity surface emitting lasers (EVCSEL) or edge emitting electron-beam-pumped lasers (EEELs). The semiconductor medium may take the form of an aluminum gallium nitride alloy that has a mole fraction of aluminum selected to give a desired emission wavelength, diamond, or diamond-like carbon (DLC). The sources may be produced from discrete components that are assembled after their individual formation or they may be produced using batch MEMS-type or semiconductor-type processing techniques to build them up in a whole or partial monolithic manner, or combination thereof

Spectroscopic Chemical Analysis Methods and Apparatus

This invention relates to non-contact spectroscopic methods and apparatus for performing chemical analysis and the ideal wavelengths and sources needed for this analysis. It employs deep ultraviolet (200- to 300-nm spectral range) electron-beam-pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor lightemitting devices, and hollow cathode metal ion lasers. Three achieved goals for this innovation are to reduce the size (under 20 L), reduce the weight [under 100 lb (.45 kg)], and reduce the power consumption (under 100 W). This method can be used in microscope or macroscope to provide measurement of Raman and/or native fluorescence emission spectra either by point-by-point measurement, or by global imaging of emissions within specific ultraviolet spectral bands. In other embodiments, the method can be used in analytical instruments such as capillary electrophoresis, capillary electro-chromatography, high-performance liquid chromatography, flow cytometry, and related instruments for detection and identification of unknown analytes using a combination of native fluorescence and/or Raman spectroscopic methods. This design provides an electron-beampumped semiconductor radiation-producing method, or source, that can emit at a wavelength (or wavelengths) below 300 nm, e.g. in the deep ultraviolet between about 200 and 300 nm, and more preferably less than 260 nm. In some variations, the method is to produce incoherent radiation, while in other implementations it produces laser radiation. In some variations, this object is achieved by using an AlGaN emission medium, while in other implementations a diamond emission medium may be used. This instrument irradiates a sample with deep UV radiation, and then uses an improved filter for separating wavelengths to be detected. This provides a multi-stage analysis of the sample. To avoid the difficulties related to producing deep UV semiconductor sources, a pumping approach has been developed that uses ballistic electron beam injection directly into the active region of a wide bandgap semiconductor material

Spectroscopic chemical analysis methods and apparatus

Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument

What Happens When Investigating A Crime Takes Up Too Much Time? An Examination of How Optimal Law Enforcement Theory Impacts Sentencing

Previous research finds that variations in sentencing outcomes still exist among similarly situated individuals, especially among drug offenders. While courtroom actors are often the focus of sentencing disparities, law enforcement officers are rarely studied. This is problematic because criminological research has yet to explore whether law enforcement could influence sentencing decisions. The current study aims to discover the influence of a previously ignored legal variable, investigation workload, on sentence length and directly examine an untested criminal justice theory, Optimal Law Enforcement Theory. This study will explore these overlooked concepts with a rare dataset that contains information on individuals convicted of prescription drug trafficking in Florida from 2011-2013. We find that investigation workload does influence sentencing, with offenders convicted from a high police workload being significantly more likely to experience longer sentences than offenders convicted from a low investigation workload. Limitations and policy implications are also discussed

Whole Systems Inquiry: Designing Large Educational Events

Whole systems inquiry (WSI) helps people see complex topics as functional activities with inputs, outputs, interactions, and performance of the system over time. The authors used WSI to design a national symposium with 800 attendees who responded to two questions at the end of 70 topical sessions. Responses were aggregated onto a mega-map, synthesized into themes, and drawn as an emerging system. Work groups compared emerging themes with national priorities while individual participants evaluated utility in their disciplinary programs. We conclude that large meetings can be designed as functional systems with participation, synthesis, and evaluation of intentional learning

Native Fluorescence Detection Methods, Devices, and Systems for Organic Compounds

Naphthalene, benzene, toluene, xylene, and other volatile organic compounds VOCs have been identified as serious health hazards. Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter "badges" to be worn by personnel potentially exposed to hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined

Native Fluorescence Detection Methods and Detectors for Naphthalene and/or Other Volatile Organic Compound Vapors

Naphthalene, benzene, toluene, xylene, and other volatile organic compounds have been identified as serious health hazards. This is especially true for personnel working with JP8 jet fuel and other fuels containing naphthalene as well as other hazardous volatile organic compounds (VOCs). Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter "badges" to be worn by personnel potentially exposed to naphthalene or other hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined. The badges employ a new native fluorescence based detection method to identify and differentiate VOCs. The particular focus of some embodiments are the detection and identification of naphthalene while other embodiments are directed to detection and identification of other VOCs like aromatic hydrocarbons such as benzene, toluene, and xylene

The Development of Day-night Differences in Sleep and Wakefulness in Norway Rats and the Effect of Bilateral Enucleation

The suprachiasmatic nucleus (SCN) exhibits circadian rhythmicity in fetal and infant rats, but little is known about the consequences of this rhythmicity for infant behavior. Here, in Experiment 1, we measured sleep and wakefulness in rats during the day and night in postnatal day (P)2, P8, P15 and P21 subjects. As early as P2, day-night differences in sleep-wake activity were detected. Nocturnal wakefulness began to emerge around P15 and was reliably expressed by P21. We hypothesized that the process of photic entrainment over the first postnatal week, which depends upon the development of connectivity between the retinohypothalamic tract (RHT) and the SCN, influences the later emergence of nocturnal wakefulness. To test this hypothesis, in Experiment 2 infant rats were enucleated bilaterally at P3 and P11, that is, before and after photic entrainment. Whereas pups enucleated at P11 and tested at P21 exhibited increased wakefulness at night, identical to sham controls, pups enucleated at P3 and tested at P21 exhibited the opposite pattern of increased wakefulness during the day. Pups tested at P28 and P35 exhibited this same pattern of increased daytime wakefulness. All together, these results suggest that prenatal and postnatal experience modulates the development of species-typical circadian sleep-wake patterns. Moreover, we suggest that visual system stimulation, via the RHT’s connections with the SCN, exerts an organizational influence on the developing circadian system and, consequently, contributes to the emergence of nocturnality in this species

Seal Oil Piping Vibration On An Oil-Free Screw Compressor In An FPSO Application.

Case StudyA dry screw compressor skid was fabricated for offshore service that included oil buffered mechanical seals on the compressor. During shop testing, excessive seal oil piping vibration was observed that resulted in pipe component failures. The oil system was designed to include a common lube and seal oil system with a pump design pressure of 590 psi. There were six oil control valves on the system, including a lube oil pressure control valve, one flow control valve on the inlet end of the compressor, another flow control valve on the discharge end, two differential pressure controllers to maintain differential pressure on the seals for each end of the compressor, as well as a back pressure control valve for the oil system. Vibration and pressure pulsation measurements indicated that the response was at the pocket pass frequency of 206 Hz. The source was determined to be at the compressor. Arrangement of the control valves and control sensing lines were likely contributors to the severity of the response. Modification to the seal oil system included addition of several volumes at strategic locations to change the acoustical characteristics of the oil system to reduce the shaking forces in the pipe system. These changes along with pipe support modifications and changes to the control valve sensing lines were successful at reducing the pipe pulsations and vibration response to acceptable levels