Test, testing scratching

Ritzel, n. (Mach.) pinion, ritzen, v.t. crack slit scratch etch cut. RitzhlLrte, /. hardness to scratching, -probe, /. abrasive hardness test, scratch test, -priifer, m. abrasive hardness tester, aclerometer. -verfahren, n. = Ritzharteprobe. -zahl, /. (scratch) hardness number. 

Skin testing is a good adjunctive diagnostic test. Scratch testing may assist in determining the allergen involved. 

A 29-year-old man developed an infiltrative maculo-papular eruption after 1 week of itraconazole 100 mg bd for tinea corporis (44). Itraconazole was withdrawn, and the lesions disappeared within 7 days. Scratch tests, patch tests, scratch-patch tests, and drug induced lymphocyte stimulation tests for itraconazole were negative however, rechallenge with systemic itraconazole induced a maculopapular eruption on the face, hands, and the dorsa of the feet. Empty itraconazole capsules had no cutaneous effects, suggesting an allergic reaction to a metabolite of the compound. 

DNP in a contact skin test (Beinhauer 1934). Patch tests, scratch tests, intradermal tests, and passive transfer tests with 2,4-DNP performed on 158 people, 117 of whom had hay fever, asthma or urticaria, were all negative (Matzger 1934). Such reactions were not reported in the occupational exposure studies, which involved inhalation and dermal exposure (Gisclard and Woodward 1946 Perkins 1919). 

There are numerous techniques known for adhesion and delamination testing, some of the most common being a tape test, stud-pull test, scratch test, and an indentation test [1]. In the tape test, a tape is pulled off the surface containing a scratch, which provides the failure initiation. In the stud pull test, a stud held with thermosetting epoxy is pulled off the film surface. The indentation test, wherein a ball is pressed into the surface, is used for hard coatings, and the failure pattern indicates acceptable behavior. In the scratch test, where an indenter moves in both vertical (loading) and horizontal (sliding) directions, an acoustic emission sensor allows for detection of the initiation of fiacture, while the scratch pattern indicates the type of failure. 

Scratch Test. Many methods have been developed for testing scratch resistance. The method standardized in ISO 1518 employs a scratching needle with a hardened steel hemispherical tip of 1 mm diameter. The needle is moved along the surface of the coating under a specified load either in a hand-operated or in a motor-driven apparatus. 

Intracutaneous tests, scratch tests, and prick tests can be performed with the drugs as such or with their conjugates, for example penicilloyl-polylysine. Type I reactions are the main field of usefulness, but the tests are also suitable for demon-... 

Arco microknife Instrument designed for testing scratch hardness and adhesion of coatings. A diamond point is weighted until it can penetrate a film to the metal substrate in two retracing steps. The weight necessary to achieve this cutting force for films of standard thickness is a measure of hardness. 

Immediate allergies can be examined by skin-prick tests, scratch tests, or use tests, and by determination of specific IgE antibodies in the patient s serum (Kanerva et al. 1991 Tarvainen and Kanerva 1999). Low-molecular-weight chemicals can be conjugated with HSA (Howe et al. 1983) before they are used in skin-prick tests or RAST examinations (Ceska and Lundkvist 1972). 

Figure 14. Surface of a Ti6A14V sample after a wear test. Scratches indicate wear at the surface.

This chapter gives a brief description of special mechanical tests for various types of material and sample geometries, such as blister tests, tensile tests, and shear tests for sealants/foam adhesives, indentation tests, scratch tests, tack tests, and tests for the evaluation of residual stresses. 

A scratch was created on the coated specimen using a rod with a diamond tip on a scratch tester (IMC-1552, Imoto Machinery Co. Ltd.). The load for the scratch was 30 g. The scratched specimen was put in a holder and connected to a conductive wire, followed by immersion in a 0.0005 M NaCl corrosive solution, maintained at 40°C. The electrochemical impedance spectroseopy of the scratched specimen was measured at intervals of 4 h, or more, for a total of 24 h. Measurement data were analysed to calculate the polarisation resistance after the test. Scratched specimens were also immersed in a 0.0005 M NaCl corrosive solution at 40°C for 7 days. The surface appearance of the specimens was observed after the corrosion test to confirm the self-healing properties of the coatings. The seratched part of the specimen was analysed after the corrosion test by Electron Probe Micro-Analysis (EPMA). 

Adhesion test, scratch An adhesion test whereby a loaded stylus with a specific tip configuration is pulled across the film surface under increasing load. The scratched surface is then observed visually for flaking and deadhesion and is correlated to the load at that point. During scratching, Acoustic emission may also be monitored. 

To 2 ml. of the ester in a test-tube add slightly more than the same volume of a cold saturated aqueous copper acetate solution. The blue colour of the latter turns immediately to a pale green. Now shake the tube vigorously in order to produce an emulsion of the ester in the aqueous layer. Scratch the sides of the tube with a rod, and shake vigorously as before. Crystallisation may be delayed for about 5 minutes, but, when once started, rapidly gives a copious precipitate... 

Dibromide formation. Dissolve 0 2 ml. of styrene in 0 5 ml. of CCI4 in a test-tube. Add slowly, drop by drop, a 10% solution of bromine in CCI4. Note the decolorisation of the bromine and absence of HBr fumes (therefore reaction by addition and not by substitution). Continue to add the bromine solution until a faint brown colour persists. Scratch the sides of the tube and cool it in ice-water. Filter off the crystals that separate and recrystallise the styrene dibromide from methanol m.p. 72 . 

NWChem (we tested Version 3.2.1) is a program for ah initio, band-structure, molecular mechanics, and molecular dynamics calculations. The DFT band-structure capability is still under development and was not included in the Linux version tested. NWChem is unique in that it was designed from scratch for efficient parallel execution. The user agreement is more restrictive than most, apparently because the code is still under active development. At the time of this book s publication, limited support was available for users outside of the EMSL facility. 

Hardness. Glass hardness tests usually measure the resistance to abrasion by grinding or grit-blasting, resistance to scratching, or penetration by an indenter. The method to be used depends on expected service conditions. Knoop hardness (Table 4) is commonly used, because other methods usually fracture the glass. 

MohsAn early (1822) hardness comparison test involved assigning a relative number to aH known materials (usuaHy minerals and pure metals) by virtue of their relative abHity to scratch one another. The results of this classification are not relatable to other properties of materials or to other measures of hardness. As a result of this limited useflilness, the Mohs hardness test is primarily used for mineral identification. Some examples of the Mohs hardness scale, which ranks materials from 1 to 10, are Hsted in Table 6. 

Scratch Te.st. The scratch microhardness test is a refinement of the Mohs test. The corner of a cubic diamond is drawn across the surface of a metaHographicaHy poHshed sample under a constant load, usuaHy 29.4 N (3 kgf). The width of the resultant Vee groove scratch varies inversely with the hardness of the material displaced where H = scratch hardness number and A = groove width in micrometers. 

This test finds appHcation on finely poHshed and/or etched metaHographic samples and mineralogical samples. It is useful for distinguishing variations in hardness between adjacent microconstituents. The test is extremely deHcate and therefore is Httle used commercially. Use is largely restricted to research institutions. There is no estabHshed means of converting scratch hardness data to other hardness scales. 

Floor poHshes typically are evaluated for gloss, appHcation and leveling properties, discoloration, sHp resistance, scratch resistance, heel-mark resistance, scuff resistance, damp-mopping and detergent resistance, repairabiHty, lack of sediment, and removabiHty (3). RecoatabiHty and formula stabiHty are also important. A review of test methods is available (35). More than 20 ASTM test methods for floor poHshes exist. From the standpoint of product safety, sHp resistance is a particularly important variable and many test methods are available (39). 

After the test, the scratch so marked should not show up the bare metal surfaee. Figure A13.4 illustrates the test arrangement. 

The surface finish of the specimen may also affect impact behaviour. Machined surfaces usually have tool marks which act as stress concentrations whereas moulded surfaces have a characteristic skin which can offer some protection against crack initiation. If the moulded surface is scratched, then this protection no longer exists. In addition, mouldings occasionally have an embossed surface for decorative effect and tests have shown that this can cause a considerable reduction in impact strength compared to a plain surface. 

Reactions under pressure are usually carried out in an autoclave. However, several simple vessels can be used for reactions at moderate pressure. A heavy walled Pyrex test tube or Kjeldahl flask drawn out and sealed with an oxygen torch makes a suitable container for many Diels-Alder reactions. The tube can be heated in an oil or water bath, but care must be exercised to protect against explosions. At the conclusion of the reaction, the tube is cooled to room temperature, the neck is scratched with a file or carborundum chip, and a hot Pyrex rod is touched to the scratch. A large crack in the neck should result, and the sealed top can be easily knocked off. 

Ritz-probe, /. scratch test or sample, -ver-such, m. scratch test. 

Even small traces of certain corrosion stimulants, notably soluble chlorides and sulphates, can maintain a continuing corrosion process under a paint film because the salts accelerate the initial dissolution of ferrous iron (and other metal ions) but are not immobilised in the hydrated oxide corrosion products. Filiform corrosion is the most spectacular example of this phenomenon, but progressive spread, preceded by blistering, is also observed from scratches or other breaks in a coating, for example during salt spray tests. 

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