Detection system COMPACT

Hattori, A., Yamaguchi, H., Yamaguchi, J., Matsuoka, Y., Kanki, S., Fukuzawa, T., Miwa, T., Totama, M., Tokeshi, M., Kitamori, T., Practical studies on compact photo-thermal lens spectroscopy detection system with micro chemical chip. Micro Total Analysis Systems 2003, Proceedings 7th pTAS Symposium, Squaw Valley, CA, Oct. 5-9, 2003, 359-362. 

The time required to achieve the maximum voltage (rise time) and to return to the minimum voltage (fall time) depends on the magnitude of the voltage applied to the separation column. It is expected that both the rise time and fall time decline when the value of the high voltage is reduced. Thus, the clock period can be reduced in ME, as the applied voltage in ME is 10-fold less than that in CE. Fister III et al. successfully demonstrated CC-ME, in which the clock period was reduced to 0.25 s (7). We also found that 0.5s was the optimal clock period for HT-ME combined with a laser-induced fluorescence (LIF) detection system equipped with a compact Nd YAG laser (18). 

FIGURE 1.11 Schematic of polymer-based detection system. The enzyme-linker antibody has a more compact molecular shape than other polymer carrier-based conjugates and thus allows the attachment of multiple conjugates in close proximity to each other. The abundant conjugated enzymatic molecules are deposited in each antigenic location, which resembles a big-city skyline. From Shi S-R, Quo j, Cote R], et al. Sensitivity and detection efficiency of a novei two-step detection system (PowerVision) for immunohistochemistry. Appi immunohistochem Moi Morphoi. 1999 7 20i-208. 

Many ditTercni types of douhle-focusing mass spectrometers are available commercially. The most sophist icaied of these arc capable of resolution in the lO range. More compact double-hicusing instrumenis can also be purchased (for considerably less money). A typical instrument of this type will have a 6-in. electrostatic sector and a 4-in. 90 magnetic deflector. Resolutions of about 2.500 are common with such instruments. Often they are employed as detection systems for gas or liquid chromatography. 

Intact soil cores with little or no detectable soil compaction can be obtained by a PVC, acrylic, or aluminum cylinder (15 cm diameter) with sharpened lower edge that can be twisted through fibrous marsh soils to a depth of 60 cm. The top of the cylinder is sealed with a PVC cap or a stopper to provide suction, and the bottom of the cylinder after soil is extracted from soil is sealed with a rubber stopper. Soil cores can then be sectioned into desired depth increments, either in the field or in the laboratory. Surface detritus (distinguishable plant litter) is removed from the soil and saved for chemical analysis. Typically, soil cores are sectioned into 0-10,10-30, and 30-60 cm for routine characterization. Selecting soil depth increments should be based on site-specific conditions and soil profile characteristics. For routine monitoring of soil properties, typical root zone depth (0-10 and 10-30 cm) may be adequate to characterize the system. 

Lee and coworkers (2006) presented a compact cell counting/sorting system with several essential components including a micromachined flow cytometer chip device, an optical detection system, and a data analysis and control system to achieve the functions of cell sample injection, optical signal detection, and cell collection. Its dimensions were 37 cm in length, 16 cm in width, and 18 cm in height (Fig. 8c) [16]. 

Galloway DL, Hudnut KW, Ingebristen SE, Philips SP, Peltzer G, Rogez F, Rosen PA (1998) InSAR detection of aquifer system compaction and land subsidence. Antelope Valley, Mojave Desert, Califomia Water Resources Research, vol 34, pp 2573-2585... 

To date, direct UV absorption sensing has been used mainly in environmental applications to monitor pollutants in the atmosphere such as ozone and NO (Wu et al. 2006), hydrocarbons, and volatile organic compounds (VOCs) (Lin et al. 2004). Fiber optic UV systems for gas and vapor analysis have been reviewed by Eckhardt et al. (2007). The strong absorbance of vapors and gases in the UV region is advantageous and has resulted in a compact detection system of good accuracy. 

The eombination in a compact system of an infrared sensor and a laser as excitation source is called a photothermal camera. The surface heating is aehieved by the absorption of the focused beam of a laser. This localisation of the heating permits a three-dimensional heat diffusion in the sample to be examined. The infrared (IR) emission of the surface in the neighbourhood of the heating spot is measured by an infrared detector. A full surface inspection is possible through a video scanning of the excitation and detection spots on the piece to test (figure 1). 

Case 2 - The Hyde Park Landfill site, located in an industrial complex in the extreme northwest corner of Niagara, New York, was used from 1953 to 1975 as a disposal site for an estimated 80,000 tons of chemical waste, including chlorinated hydrocarbons. A compacted clay cover was installed in 1978 over the landfill and a tile leachate collection system was installed in 1979. Hazardous compounds such as ortho-, meta- and para-chlorobenzoic acid toluene ortho- and meta-chlorotoluene 3,4-dichlorotoluene and 2,6-dichlorotoluene were detected in the leachate (Irvine et al., 1984). Since 1979, the existing leachate treatment system has used activated carbon as the technology for removing organic carbon. Although... 

Miniaturisation of scientific instruments, following on from size reduction of electronic devices, has recently been hyped up in analytical chemistry (Tables 10.19 and 10.20). Typical examples of miniaturisation in sample preparation techniques are micro liquid-liquid extraction (in-vial extraction), ambient static headspace and disc cartridge SPE, solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE). A main driving force for miniaturisation is the possibility to use MS detection. Also, standard laboratory instrumentation such as GC, HPLC [88] and MS is being miniaturised. Miniaturisation of the LC system is compulsory, because the pressure to decrease solvent usage continues. Quite obviously, compact detectors, such as ECD, LIF, UV (and preferably also MS), are welcome. 

U.S. EPA s rationale for the requirement of composite bottom liner option in the final doubleliner rule is based on the relative permeability of the two liner systems.13 The results of numerical simulations performed by U.S. EPA,10 which compared the performance of a composite bottom liner to that of a compacted soil bottom liner under various top liner leakage scenarios, showed that liquids passing through defects in the top FML enter the secondary LCRS above the bottom liners. The hydraulic conductivities of bottom liner systems greatly affect the amount of liquids detected, collected, and removed by the secondary LCRS. 

U.S. EPA bases its 1 gallon/acre/day leak detection sensitivity on the results of calculations that show that, theoretically, an LDS overlying a composite bottom liner with an intact FML component can detect, collect, and remove liquids from a top liner leak rate <1 gallon/acre/day. This performance standard, therefore, can be met with designs that include a composite bottom liner. Based on numerical studies, one cannot meet the leak detection sensitivity with a compacted soil bottom liner, even one with a hydraulic conductivity of 10-7 cm/s. Therefore, the emphasis of this standard is on selecting an appropriate bottom liner system. 

However, the most significant development in recent years has been represented by the trend towards smaller facilities based on smaller accelerators. The work done at ETH in Zurich on the study of stripping yields, molecular dissociation and detection efficiency at low energies has led to the development of systems based on low voltage tandem machines they have demonstrated that 14C measurement is also possible using 500 kV or even 200 kV accelerators.[61,62] The main advantage in the use of dedicated 14C smaller accelerators is the reduced space requirements [63] for example, while the 3 MV VERA facility covers an area of 192 m2, the compact 500 kV AMS system at the Poznan Radiocarbon Laboratory in Poland covers an area of 30 m2 and the 200 kV MICADAS system in Zurich only about 7 m2. 

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