42262 Taylor, M.A. Evaluation of concrete constituents using photon radiation N o n d e s t r u c t i v e Tes t ing , SP 112, pp. 41-62. E d i t e d by H.S. Lew, A m e r i c a n C o n c r e t e Ins t i tu t e , D e t r o i t (1988)

Gamma ray absorption techniques were used to determine the amounts of each component in a system of mixtures (such as concrete). The technique uses photons of several energies in contrast to previous applications where only one energy was employed. The use of multiple energies contains more information than the single beam system and thus more properties can be determined. Several possible models for cementitious materials are discussed and compared. The paper presents the experimental determination of the initial data set needed prior to prediction experiments. One predictive technique is evaluated by comparison with "blind" tests.

42259 Nambissan, P.M.G.; Sen, P. Positron annihilation studies on alpha irradiated tungsten Solid Sta te C o m m u n i c a t i o n s , Vol. 71, No. 12, pp. 1165-1167 (Sep. 1989)

Positron annihilation Doppler broadening measurements on alpha- irradiated tungsten show the effects of dissociation of vacancy- impurity complexes below 400°C. Above this, vacancy migration and formation of vacancy clusters are observed. Isochronal recovery of these clusters is seen

0 around 550 C. Vacancy loops and microvoids so formed are found stable tipto 700°C beyond which they anneal out.

42242 Goebbels, J.; lllerhaus, B.; Kettschau, A.; Reirners, P. Nondestructive testing of vitrified radioactive waste by computerized tomography C e r a m i c F o r u m I n t e r n a t i o n a l , Vol. 66, No. 7/8, pp. 288-291 (1989)

Computerized tomography (CT) is used to assess the homogeneity of glass used for the vitrification of highly radioactive waste, the glass melt is placed in steel casting dies before final storage in a salt dome. Saline corrosion, following water ingress accidents can attack the steel jackets. The quality of this casting can also be assessed by this method. X-ray and gamma radiation CT images have revealed numerous cracks and shrinkage cavities and pronounced bubble formation and inclusions in some dies. Other dies were found to contain nearly homogeneous glass blocks.

42148 Crescenzo, E. Applications of gamma- and X-radiometry in the areas of measure- ment, nondestructive testing and material analysis (In French) Oual i t e . R e v u e Pra t ique de C o n t r o l e Indus t r i e l , No. 158, pp. 60-69 (Sep. 1989)

42092 Union Rhein Braunkohlen Meta l pipeline checking system for corrosion detection - uses source providing X-ray or gamma radiation directed through pipe at angle to pipeline axis E u r o p e a n Pa ten t No. 310,874 (19 May 1989)

42063 Hussein, A.M.A. Radiation scattering methods for non-destructive testing and imaging I n t e r n a t i o n a l A d v a n c e s in N o n - D e s t r u c t i v e Tes t ing , Vol. 14. E d i t e d by W.J . M c G o n n a g l e , pp. 301-321. G o r d o n and Breach Science Publ i shers 371 pp. (1989) ISBN 2881243274

Radiation scattering methods offer advantages over conventional trans- mission-based radiographic and tomographic techniques. Measurement of scattered radiation requires access only from one side of the object and provides valuable information on the density and composition of the inspected material. This paper discusses the physical principles of utilizing the scattering of photons (X- and gamma radiation) and neutrons for non-destrucfive testing and imaging purposes. Previous and current techniques are examined and existing as well as potential applications of the scattering method are explored.

42061 Na]os, M.J.; Lopes, R.T.; Borges, J.C. Compton scattering of gamma-rays as surface inspection technique Nuc lea r I n s t r u m e n t s & M e t h o d s in Physics R e s e a r c h , Vol. A280, Nos. 2-3, pp. 535-538 (10 Aug . 1989)

A system for surface inspection based on the physical principle of Compton scattering of gamma-rays is presented here. Our system consists of a collimated 137 Cs source and a Nal(TI) detector. An experimental search was carried out to determine the best layout of the array. A set of aluminium blocks with different surface conditions has been tested, and imperfections up to 1.6 mm were detected.

41822 Schilling, C.H.; Aksay, I.A. Gamma-ray attenuation analysis of packing structure evolutioff during powder consolidation Pacific N o r t h w e s t L a b o r a t o r y , W a s h i n g t o n ( U n i t e d Sta tes) , PNL- SA-15087, D E 8 8 007840, CONF-8711115-6 , 10pp. (1988)

Gamma-ray attenuation measurements enable non-destructive analysis of powder packing density heterogeneities which develop during consolidation of ceramic compacts. In situ measurements of gamma-ray attenuation were performed during sedimentation of aqueous alumina suspensions to evaluate the role of suspension pH on particle rearrangement processes in cast layers. These data are used to support consolidation kinetic models describing processes of agglomerate restructuring and cast layer compaction. Porosity defects in sintered casts are correlated with pH-dependent processes of pore closure detected during sedimentation.

41820 Hussein, E.M.A. Radiation scattering methods for nondestructive testing and imaging I n t e r n a t i o n a l A d v a n c e s in N o n d e s t r u c t i v e Test ing. E d i t e d by W a r r e n J. M c G o n n a g l e . Vol. 14, pp. 301-321, G o r d o n and Breach Science Publ i shers (1989)

Radiation scattering methods offer advantages over conventional trans- mission-based radiographic and tomographic techniques. Measurement of scattered radiation requires access only from one side of the object and provides valuable information on the density and composition of the inspected material. This paper discusses the physical principles of utilizing the scattering of photons (X- and gamma radiation) and neutrons for nondestructive testing and imaging purposes. Previous and current techniques are examined and existing as well as potential applications of the scattering method are explored.

41684 Schlieper, G.; Arnhold, V.; Kozuch, A. Non-destructive determination of sectional densities by the gamma- densomat Nondes t ruc t ive Tes t ing of H i g h - P e r f o r m a n c e Ce ramics , C o n f e r e n c e Proceed ings , Bos ton , Massachuse t t s , ( U n i t e d S ta tes ) , 25-27 A u g . 1987, pp. 457-471. E d i t e d by A. Vary and J. Snyder . The A m e r i c a n C e r a m i c Socie ty (1987)

The Gamma-Desomat is used to determine sectional densities of green powder compacts and sintered components nondestructively. Measurement is based on the absorption of gamma rays in solid materials and provides a number of technical and economic advantages over the conventional method of density determination (Archimedes principle). The Gamma-Desomat can increase the output of compacted parts by about 5% through reduced tool set up times. Tool wear and tool fractures can be minimized, and the influence of wall friction on the density distribution can also be determined. In cases where it is difficult to cut suitable test pieces for conventional density determination, the Gamma- Densomat provides an easy way to obtain precise results. Although most of the practical work cited in this paper deals with powder metallurgical parts, the applicability of the method to ceramic parts has been demonstrated in two examples.

41585 Albugues, F. Nondestructive tests and high performance composite structures Societe N a t i o n a l e Indus t r i e l l e A e r o s p a t i a l e , Sa in t -Meda rd -en - Ja i l e s (France) , N88-28969/9 /GAR, 17pp (1988)

The most efficient nondestructive test methods applicable to high performance carbon or kevlar reinforced plastics are reviewed including the hard X or gamma radiation methods such as X-ray tomography, neutron photography and Compton scattered diffusion, holographic methods, acoustic emission methods, and microwaves. The examples show that each method has a definite area of application.

41569 Reddi, D. V. Role of NDIE d u r i n g five decades of quality assurance of armaments Ind ian Non-Des t ruc t i ve Inspec t ion Jou rna l , Vol. 7, No. 6, pp. 35-46 (Mar . 1989)

A historical perspective is given of non-destrucfive inspection of armaments to assure their quality in India prior to the Second World War. A wide range of techniques were used and details of the application of each is given. The techniques include radiography, magnetic particle inspection, ultrasonic testing, penetrant testing, eddy currents, x-ray diffraction and surface and visual examination.

41553 Gould, L. Sensors in food processing Sensors , Vol. 6, No. 4, pp. 15-25 (Apr . 1989)

Precise sensing of the three primary process variables in continuous food production - flow, level, and temperature - is not only possible, but a matter of routine in some advanced installations. The hallmark of these flow, level, and temperature sensors is their continuous in- process performance. Some feature non-contact capabilities, using energy ranging from infrared to ultrasonic to gamma rays; others are based on fiber optics, magnetics, and new applications of physics.

41452 Bridge, B.; Harirchian, F.; Imrie, D.C.; Mehrabi, Y.; Meragi, A.R. Compton scatter imaging: corrosion, thickness monitoring and void detection Proceed ings of a one -day Mee t i ng of the Mate r i a l s and Tes t ing G r o u p of the Ins t i tu te of Physics, 13 D e c e m b e r 1988, London . Eds . N. M a c C u a i g and R. Hol t . pp. 17-39 (1989)

An overview is presented of the research programme on Compton scatter imaging at Brunel University carried out with the use of 1.5 mCi Ba-133 and 10 Ci Co-60 gamma sources. Effective methods of radiological imaging were established for the underwater non-destrucfive inspection of thick structural sections, of offshore oil production platforms. The problems associated with the design of imaging systems sufficiently mobile and robust for suhsea usage are discussed. Typical results for the detection of inner wall corrosion pits and wall thickness measurements are given. The performance of the technique in detecting voids is insensitive to material density. Thus the measurement time required to achieve a specified detection probability for a given void size, is almost the same in polyethylene, as in steel.

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