Spectral Reading Research Articles

Soil surface spectral data from Landsat imagery for soil class discrimination

The aim of this study was to develop and test a method to determine and discriminate soil classes in the state of Sao Paulo, Brazil, based on spectral data obtained via Landsat satellite imagery. Satellite reflectance images were extracted from 185 spectral reading points, and discriminant equations were obtained to establish each soil class within the studied area. Sixteen soil classes were analyzed, and discriminant equations that comprised TM5/Landsat sensor bands 1, 2, 3, 4, 5, and 7 were established. The results showed that this methodology could effectively identify individual soil classes using discriminant analyses of the spectral data obtained from the surface. Success rates of > 40% were achieved for 14 of the 16 evaluated soil classes when applying the satellite image data. When the 10 soil classes containing the largest number of minimum cartographic areas were used, the hit rate increased to > 50%, for seven soil classes with a global hit rate of 52%. When the soil classes were grouped based on their parent materials, the hit rate increased to 70%. Thus, we concluded that the spectral method for soil classification was efficient.

Spectral Readings

By enlisting material objects in the service of ideology critique, materialist criticism tends to dematerialize solid objects whose historical trajectories have been lost to performed memory ( kinamnesia ). A diachronic reading of Richard II ’s crown models how materialist criticism can reconstruct the ways that mobile physical objects set unstable, politicized meanings in motion at different levels of analysis. In addition to such elusive material stuff, theatre is made up of dark matter: an invisible dimension that evades detection, even though its effects are palpable in performance. Macbeth’s dagger is not there onstage, but it is not not there either. Dark matter resists semiotic and materialist analysis because it sheds no visible light. Detecting dark matter—offstage spaces and actions; absent characters; the narrated past; hallucination; blindness; obscenity; godhead; and so on—invites a new approach known as spectral reading. Both visible and dark objects matter in performance, but they matter in ways that demand distinct critical vocabularies.

Whole blood reflectance for assessment of hematologic condition and detection of angiographic contrast media

We present simple whole blood reflectance analyses in the range 500-900 nm, using intact whole blood to simultaneously quantify hematocrit and oxygen saturation from a single spectral reading. We applied these results for the development of an intravascular catheter-based reflectance sensing system to detect and remove contrast media injected during angiography so as to reduce the risk of complications associated with the injected contrast media. We further tested the practicality of the optical detection of angiographic contrast media in a pilot animal study in vivo. We successfully demonstrated the feasibility of real-time in vivo contrast detection and removal during angiography. Our simple method for the detection and removal of angiographic contrast media will facilitate the development of intravascular optical sensing systems.

Fine Tuning of the Spectral Sensitivity in a-SiC:H Stacked p-i'i-n Graded Cells

AbstractIt is presented in this work a p(a-SiC:H)/i(a-SiC:H)/i((a-Si:H)/ n(a-Si:H) single junction for application in color sensing domain produced with the PECVD technique. The interest of this device resides in its simplicity of realization and utilization, as it takes advantage from the well known properties of the a-Si:H p-i-n junctions together with the possibility of color filtering by tailoring the optical gap of a-Si:H with the introduction of a small percentage of Carbon. The thicknesses of the i(200 nm) and i (1000 nm) layers are optimized for light absorption in the blue and red ranges, respectively. Measurements of the spectral response under forward and reverse polarization show a dependence of the wavelength of the maximum absorption on the intensity of the applied bias. A comparison of the photocurrent reading with and without a 650 nm background DC optical bias permits a complete separation of blue and red color under reverse and forward applied bias, respectively. The application of the LSP technique (AC regime of the optical bias) permits a complete RGB reading of the incoming light. Simulation results obtained with the program ASCA will support and explain the measurements about spectral response and photocurrent reading under DC and AC regimes.

Miniaturized linear time-of-flight mass spectrometer with pulsed extraction.

Improved resolution for a miniaturized instrument is demonstrated at high masses using a pulsed extraction, 3(") linear time-of-flight (TOF) mass analyzer. This illustrates the utility of a small and simple mass spectrometer for biological/medical analyses. Current and future applications suggested by this instrument include rapid mass spectral reading of oligonucleotides that differ in one base (single nucleotide polymorphisms), distinction of biomarker signatures from different species of bacterial spores (biological weapons detection) and point-of-care instruments for proteomics-based diagnostics. We have incorporated a two-stage, pulsed-extraction design that places the focal plane of the ions at the detector channel plate surface. The ions are accelerated to a total energy of 12 keV to enable detection of high-mass proteins in a design that incorporates a floatable flight tube set at the voltage of the front channel plate of the detector. The resultant elimination of post-acceleration at the detector is intended to improve mass resolution by reducing the difference in arrival times between ions and their neutral products. Resolutions of one part in 1200 at m/z 4500 and one part in 600 at m/z 12 000 have been achieved. Proteins with molecular masses up to 66 000 Da, mixtures of oligonucleotides, and biological spores have all been successfully measured, results that increase the potential use of this TOF analyzer.