Sharpening filters

When a question exists about whether the carving is ancient, an examination under uv illumination can be very helpful. For example, an aged marble surface exhibits, under a properly filtered mercury lamp, a mellow, brownish fluorescence, whereas a fresh surface, under the same conditions, appears purple. It is not uncommon that old carvings have been sharpened this is detectable with the microscope and under uv examination. 

Diethyl sodium phthalimidomalonate (Barger and Weichselbaum, Organic Syntheses, 1943, Coll. Vol. II, 3B4) (6.52 g) was dissolved in boiling methyl ethyl ketone (BO ml) and a solution of p-nitrobenzyl chloride (3.44 g 1.0 mol) in the same solvent (20 ml) was added. Sodium iodide (ca 0.5 g) dissolved in hot methyl ethyl ketone (10 ml) was introduced, and produced an immediate precipitation. The mixture was refluxed for 1.5 hours, cooled, filtered, evaporated under vacuum and the residual gum crystallized from ethanol. The di-ethyl-p-nitrobenzyl-phthalimidomalonate formed colorless prisms (B8%), MP 103° to 105°C, sharpening to 104° to 105°C on recrystallizing from ethanol. 

The simplest way to sharpen up such data in the frequency domain is to use a Wiener filter (Press et al. 1986 Kino 1987). In the time domain, each... 

How can this be solved Clearly there are limits to the amount of peak sharpening that is practicable, but the filter function can be improved so that noise reduction and resolution enhancement are applied simultaneously. One common method is to multiply... 

The MQ-filter sandwich was similarly transferred to the filter-rinsing stand, the top 149-jLtm Nitex support was folded back, and three sharpened acrylic tubes were pressed into the filter pair. The MQ-filter area not enclosed by the acrylic tubes was rinsed with several aliquots of deionized water (totaling 200-300 mL) with suction alternately applied from below to reduce sea salt by an order of magnitude this process was required for accurate dry-weight and major-ion determinations. The acrylic tubes were subsequently removed, and the fresh, unrinsed subsamples were preserved for lipid analysis. The remaining filter material was dried at 60 °C for >24 h. Both the MQ and 53-jitm Nitex samples were stored and transported flat in individual polyethylene bags to prevent loss of material. 

If the compound dissolved in the hot solvent and crystallized on cooling, the crystals should be obtained and their melting point determined in order to see whether purification has been effected. This may be done by collecting the crystals on a Hirsh or other type of microfunnel. However, the following technique is more convenient. A circle of filter paper about 13 mm in diameter is cut out with a well-sharpened cork borer. This is placed over the mouth of the test tube, and a hollow glass tear (Fig. 2-20) is placed over the filter paper. A retaining wire made from 20-gauge nichrome wire is placed over the tear, and a... 

Before around 1980, it was thought that the processing may have two levels. First the basilar membrane and fluid provide the correct place for a given frequency (a purely mechanical first filter ). Subsequently, the micromechanics and electrochemistry in the organ of Corti, with possible neural interactions, perform a further sharpening (a physiologically vulnerable second filter ). 

Figure 7 Sharpening of image features before (a) and after (b) spatial filtering.

Lenses are sometimes used to focus both source and detected light. Concave, convex, biconvex, and other converging lenses have been used. Loock et al. [8] formed a convex lens directly onto the ends of the fibers (Table 1, 8th row). Fuji et al. [9] fabricated lenses into the chip PDMS structure (Table 1, 14th row). In some cases, filters are also used to sharpen the signal. The most popular filters are the band-pass and dichroic variety. 

Use sharpening, edge detection, or noise reduction filters globally across the... 

---