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The application of the serial sectioning technique for the reconstruction of spatial microstructures is demonstrated using two single phase polycrystalline microstructures as examples. The materials examined are an austenitic steel and a ZnO ceramic. The practical procedure is described as well as the analysis of the planar sections. The spatial grain size distribution and number of grains per unit volume are determined using parameters obtained from planar sections. Significant differences are found between the determined spatial grain size distribution, given in histogram form, and values obtained using stereological models

Melanoma is a clinically and biologically diverse malignancy for which complete surgical excision offers the only chance for cure. Current guidelines for surgical excision margins are based on consensus recommendations, and clear, evidence-based data to guide the surgeon in each case is limited. Mohs micrographic surgery (MMS) offers the surgeon the ability to assess 100% of the surgical margin, far better than margins evaluated with the standard bread-loaf sectioning technique. Immunohistochemical stains such as MART-1 allow for the reliable identification of melanoma in frozen sections and produce cure rates at least as good as standard excision with traditional margins.

International audience; Surface degradation and cracking of dense hydroxyapatite were evaluated through Vickers micro indentation using indentation loads ranged from 25 gf to 2000 gf. Crack lengths, imprint diameters and the number of lateral cracks and chips were measured using SEM. The crack length-indentation load data were analyzed with regard to the specific relations of Palmqvist and fully developed radial cracks. Crack type transition load from Palmqvist to median crack was experimentally assessed through serial sectioning technique. The analytical estimated transition load, based on the theoretical relation of the indentation load and crack lengths showed a good agreement with one obtained from experimental itinerary. Palmqvist and median cracks were identified in low and medium indentation loads, respectively. High indentation load could also lead to the formation of lateral cracks and chips. The tendency for lateral cracking was evaluated taking into account the number of lateral cracks and chips. The chips were found to be appeared just after test in higher indentation load, whereas in medium loads they could be detectable only after several weeks.

Residual stresses have long been of concern to engineers and materials scientists, as these stresses can have a strong effect on the performance of materials and hence on the structures in which these materials are used. Some techniques do exist for the evaluation of residual stresses, e.g. destructive hole drilling techniques and techniques based on ultrasonic measurements. However, so far the majority of residual stress measurements have been done using the well established X-ray diffraction technique. This technique is widely used for studies of surface residual stresses, and by applying a destructive etching or sectioning technique, the method can also give information about the residual stress state below the surface of structures.

The diffusion behaviour of 95 Zr tracer in a series of ZrAg alloys (0–5.15 at% Ag) is investigated in the temperature range between 1200 and 1520 K, by employing the serial sectioning technique. The self-diffusivity data have been analysed on the basis of the “omega-embryo” mechanism. Based on this data, “omega”-instability temperatures in ZrAg alloys have been evaluated. It is observed that the instability temperature decreases with increase in the sliver concentration in the alloy.

Mohs micrographic surgery (MMS) is the gold standard for the excision of locally invasive cutaneous malignancies in human dermatological surgery. Using a unique horizontal sectioning technique, MMS enables 100% surgical margin assessment and provides the lowest recurrence rates for locally invasive tumours. The purposes of this preliminary study were to explore the feasibility of application of MMS in the veterinary setting and to establish practical advantages and limitations of its use in a pilot programme. It was hypothesized that MMS technique could provide 100% tumour margin assessment using frozen and/or formalin-fixed horizontal histopathologic sections. Tumour excision and colour-coded mapping were performed, and specimen tissue was fixed using either frozen sections or formalin-fixed sections. Horizontal sections were assessed for quality and presence and location of neoplastic cells based on the mapped orientation. The MMS technique was used in the excision of six squamous cell carcinomas and five mast cell tumours. In all cases, the MMS permitted 100% tumour margins examination.

Die Diffusionsparameter von Stickstoff (0 bis etwa 0.3 Ma%) in hochlegierten austenitischen Stahlen (12 bis 19 Ma%Cr, 12 bis 16 Ma%Ni, 0 bis 2 Ma%Mo) wurden im Temperaturbereich von 1283 bis 1573K ermittelt. Die geringen Konzentrationsgradienten von N konnten mittels folgender Methoden erfolgreich untersucht werden: (1) Kombination von mechanischer Schichtenteilung und chemischer N-Analyse bzw. Rontgenstrahl-Gitterparametermessung (2) Elektronenstrahl-Mikroanalyse (ESMA) oder KOSSEL-Ruckstrahltechnik am metallografischen Querschliff. Die N-Diffusionskoeffizienten (DK) wurden als konzentrationsunabhangig gefunden. Die Legierungselemente Cr und Mo senken das Diffusionsvermogen des N in hochlegierten austenitischen Stahlen, welches andererseits durch Ni erhoht wird. Eine Erklarung dafur kann im Zusammenhang mit einer Analyse der Wechselwirkungsparameter gegeben werden. Interdiffusion of nitrogen in high-alloy austenitic CrNi(Mo) steels Parameters of the diffusion of N (0 to 0.3 wt.%) in austenitic stainless steels (12 to 19 wt.%Cr, 12 to 16 wt.%Ni, 0 to 2 wt.%Mo) were determined within the temperature range of 1283–1573K. The small concentration gradients of N were successfully investigated using (1) mechanical serial sectioning technique in combination with either chemical N analysis or x-ray precision lattice parameter determination, (2) measurements on microsections by means of either Electron Probe Microanalysis or KOSSEL technique. The diffusion coefficients of N were found to be independent of its concentration. The alloying elements Cr and Mo reduce the N diffusivity in austenitic stainless steels which on the other hand is increased by Ni. An explanation of these results can be given in connection with the analysis of interaction parameters.

The diffusion of 59Fe in Incoloy 800 has been studied using the serial sectioning technique in the temperature ranges 1020–1500 K for volume diffusion and 750–1100 K for grain boundary diffusion, respectively. The volume diffusion coefficients can be represented by the expression: D(1020–1500 K)=3·26×10−5 exp (−259·6 kJ mol−1/RT) m2 s−l. The grain boundary diffusion coefficients were evaluated in most of the experiments using Whipple's method. For afew specimens, Suzuoka's method was applied. The penetration depths beyond which these methods were to be applied to analyse the experimental results were determined both graphically and by extensive use of autoradiographic techniques. The grain boundary diffusivities can be expressed as: Dgb (750–1100 K)=1·88×10−5 exp (−160·7 kJ mol−1/RT) m2 s−1, The results are discussed and presented in this paper.MST/l193

Hot torsion is frequently employed to simulate multipass thermomechanical rolling. While flow behavior, observed through shear stress versus shear strain, is typically used to characterize hot deformation and softening behaviors, the resulting microstructures can also provide significant insight into microstructural evolution and strain accumulation during the hot deformation process. A preferred approach for the analysis of microstructural features resulting from hot torsion is presented. Torsional strain paths are reviewed and compared with traditional hot rolling deformations. A tangential sectioning technique, combined with supporting fundamentals, is also presented. Microstructural observation of steels thermomechanically deformed in hot torsion verified the ability to reasonably quantify strain from microstructural analysis. This approach offers a new method for assessing shear strain accumulation within local regions of a body plastically deformed in torsion, and should provide a useful complement to the assessment of mechanical responses in hot deformation studies.

Grain-boundary heterodiffusion of iron in pure copper and self diffusion of iron in copper–0.091at% iron were measured by the serial sectioning technique in the Harrison B-regime. The penetration profiles corresponding to iron heterodiffusion in pure copper show a strong positive curvature far beyond the (Dvt)1/2 depth . This peculiar shape, which does not exist for self diffusion in the solid solution, proves the presence of a strong non linear grain-boundary segregation of iron in copper in spite of the respective surface energies of these metals. This segregation is linked to the size effect which is, as predicted by numerical simulation, the main driving force for grainboundary segregation.

Microleakage at the cervical tooth/restoration interface of class II restorations was evaluated, either on multiple sections or on teeth rendered transparent, in order to determine whether a modified clearing protocol could be established as a routine method for microleakage evaluation in class II restorations. Forty-eight class II cavities were restored with a composite/bonding agent (Tetric Universal/Heliobond, Vivadent, Schaan, Liechtenstein) in bulk technique (BT) (n=24) and with a composite/dentin adhesive system (Tetric Universal/Heliobond/Syntac Classic) in increments (IT) (n=24). The 24 specimens were assigned to two groups. Group I: dye penetration (India ink), multiple sectioning (conventional method). Group II: dye penetration (India ink) and modified clearing protocol. Linear microleakage (% dye/section) along the cervical tooth/restoration interface on multiple sections, and microleakage patterns (% dye/surface) at the cervical surface on transparent teeth were evaluated with an image analyzing system. The data were statistically analyzed with the Mann Whitney U-test, Wilcoxon's rank sum test, and the error rates method. The application of the modified clearing protocol allowed for distinct evaluation of microleakage patterns. Either protocol revealed lower penetration values for IT than for BT. With the conventional protocol, the median (25–75% percentiles) percentage of dye penetration was 2% (1–46%) for IT and 40% (23–85%) for BT. The clearing protocol revealed dye penetration of 5% (1–22%) for IT and 16% (4–24%) for BT. The clearing protocol together with the use of India ink as tracer allows for evaluation and visualization of the continuous distribution of microleakage at the cervical tooth/restoration interface without loss of information due to sectioning, although this method seems to be less discriminative than the conventional sectioning technique.

Here, we briefly discuss the physical properties and biological nature of the surface region of intertidal sediments. Data to highlight the microspatial variability within sediments and emphasise the inherent linkage between physical properties and biological processes are presented. The nature of the intertidal depositional environment is discussed with reference to the conditions which sediment-inhabiting microbes must withstand. The horizontal and vertical distribution of microbial assemblages is considered against the penetration of light and oxygen into cohesive sediments. These data are supported by fine scale analysis of sediment properties using a novel freeze sampling and sectioning technique. The visualisation of sediment assemblage microstructure by low-temperature scanning electron microscopy is shown against the background of the extremely steep gradient of change found across the surface sediment layers. The biodiversity of microbial assemblages is considered in relation to recent developments in molecular techniques. The requirement for an integrated approach to the processes occurring at the sediment/water interface isemphasised.

The autosomal dominant inherited syndromes of Hornstein and Knickenberg (HKS), and Birt, Hogg and Dube (BHDS) are both characterized clinically by the overall spread of multiple flesh coloured papules of the skin. However, it is a matter of debate if colonic neoplasms (adenomas as well as adenocarcinomas) are associated findings in the HKS or rather in the BHDS. Furthermore, histological differences are said to exist between the skin lesions in the two syndromes: whereas perifollicular fibromas were described in the HKS, fibrofolliculomas and trichodiscomas were found in the BHDS. In the present study, we report on a father and his daughter in whom we initially diagnosed a BHDS. We then examined a greater number of the papular lesions in histologic sections cut vertically as well as horizontally to the epidermis. Our results indicate that the histologic differences between the skin lesions in the two syndromes are artificial ones, caused by interpretation of different sectioning planes, and that consequently HKS and BHDS are the same. Therefore, it is necessary to look for colonic polyps in the syndrome in question, regardless if one prefers the name HKS or BHDS for it.

The electron spin resonance (ESR) technique was used to investigate the diffusion of Cr 3+ in magnesium oxide (MgO) powders. The ESR absorption intensity was measured for several annealing times and four different temperatures of isothermal annealing: 1223, 1273, 1323 and 1373 K. The activation temperature for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be E A =212±9 kJ mol −1 . This result is about 30% smaller than similar data obtained for single-crystal MgO using the radioactive-tracer sectioning technique. The difference is attributed to a higher concentration of defects in the powder relative to single crystals.

Objectives . Focused ion-beam (FIB) etching, commonly used as a cross-sectioning technique for failure analysis of semiconductor devices, has recently been applied to biological tissues to expose their ultrastructure for examination. It was the aim of this investigation to determine the practical utility of FIB to cross-section resin-dentin interfaces in order to morphologically evaluate the completeness of resin penetration into the exposed collagen scaffold at the resin-dentin bond interface. Methods . Two representative commercially available dentin adhesive systems were bonded to mid-coronal dentin. After appropriate fixation and dehydration of the resin-bonded dentin samples, a scanned focused ion-beam of a few tens of nano-meters in diameter was used to cross-section the resin-dentin interface. Examination of the interfacial ultrastructure was accomplished using a field-emission SEM. Results . Results indicate possible artifact production at the cross-sectioned interface, hiding its actual ultrastructure, probably due to a heat-effect with possible recrystallization. Further studies of FIB are needed to optimize its usefulness for resin-dentin interface examinations and other biological tissue applications. Significance . Complete resin saturation of the demineralized dentin surface-layer has been claimed to be the key factor for a long-lasting resin-dentin bond. A “clean” artifact-free micro-cross-sectioning technique may provide indisputable ultra-structural information about the depth of resin penetration into the demineralized zone. Such a test would be useful in the development of dentin adhesive systems.

The pharmacodynamics of a drug need to be clarified before it can enter the market. The intraocular penetration of drugs which are expected to be used for a long term such as anticataract or anti-glaucoma drugs is a significant problem that we have to fully resolve before commencing their use in clinical trials. The previous studies concerning inrralenticular drug penetration have been performed on entire lens samples, because of technical problems with analysis. In those investigations, the drug concentration obtained was an average value of the whole lens. In cases where small doses of the drug penetrated into only a limited area, the drug concentration in the entire lens might have been shown as below a detected level. In 1987, a new technique that overcame this disadvantage was introduced into the lens research field as a microsectioning analysis of the lens 1. Utilizing this technology, regional lens layer analysis became possible and much new information was obtained which was not possible from the previous methodology 1,2. Recently, the author applied this regional lens layer analysis to a drug penetration study in the lens and we found that highly localized low drug concentrations which were not detected in the entire lens samples could be detected with regional lens analysis3. This demonstrates that entire lens analysis is an inadequate method of detecting such low concentrations in the lens. In this study, the author again attempted to investigate inrralenticular drug dynamics utilizing a lens sectioning technique.

This paper presents the research results of the morphology of subsurface damage (SSD) in BK7 glass ground with on-machine fabricated PCD micro tool. Grinding generated damages are assessed and characterised using bonding interface sectioning technique combined with field emission scanning electron microscopy (FESEM). Both the damage depth and surface roughness are found to be influenced by the depth of cut, feed rate and spindle speed. Two major type of grinding damage have been identified likely chipping damage and micro-cracking damage. Lateral, median and cone cracks are found to be existed in the sub-surface. These crack size varies from below to above 1 μm. The mechanism of damage nucleation and propagation are discussed also. Although the machined surface seems to show ductile mode behaviour even at higher material removal, analysis of subsurface damage shows that the material removal is a combined effect of grain dislodgement, micro-cracking and plastic deformation.

The multifocal nature of adenolymphoma of the parotid salivary gland was studied in 24 patients who underwent parotidectomy. Twenty-six resected specimens were examined by a step-serial whole-organ sectioning technique; multiple adenolymphoma was found in 13. The maximum number of synchronous tumours in any gland was four. Salivary epithelial elements were found embedded within lymph nodes in nine resected specimens. Synchronous or metachronous bilateral tumours were found in eight patients. The multifocal nature of adenolymphoma of the parotid gland is demonstrated.

Composite inlays were fabricated in standardised cavities cut into aluminum and perspex blocks using a computer controlled milling process. Four materials were used to construct the inlays. These were fabricated using an indirect technique following the manufacturers' recommendations, where applicable. In addition, for one of the composites, the fabrication procedures were modified. The fitting accuracy of the restorations was assessed by taking elastomeric impression wash replicas of the luting space and by examination of sectioned restored units using image analysis. The former method indicated significantly reduced fitting accuracy when either use of die spacer or secondary curing was omitted from restoration construction resulting in incomplete seating. The sectioning technique indicated that more factors appeared to significantly reduce fitting accuracy including bulk packing, alteration in curing time, omission to die spacer and the final polishing procedure. This method also provided more specific information concerning sites of premature contact. One material gave rise to significantly greater film thicknesses using both methods of assessment. No direct correlation was found between the two techniques of fit evaluation but both methods taken together provided complementary information.

In this short technical note the construction and use of a simple microtome for sectioning critical point dried (CPD) specimens mounted on stubs are outlined. The rigidity of CPD specimens allows for light microscopically controlled sectioning by which the internal structure of plant organs or individual cells becomes visible. If compared with cryo-fracturing, this sectioning technique enables repeated sectioning through any exactly chosen plane, cell or nucleus of the specimen

The electron spin resonance (ESR) technique was used to investigate the diffusion of Fe 3+ in rutile (TiO 2 ). ESR absorption intensity was measured for several annealing times and three different temperatures of isothermal annealing: 1273, 1323 and 1373 K. The activation energy for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be E A = 215 kJ mol −1 . This result is consistent with experimental data using the radioactive-tracer sectioning technique and represents an independent measurement of the activation energy for diffusion of trivalent iron in rutile, which is difficult to achieve by other means in this mixed-valence system.

The diffusion of 45Ca has been measured in single crystals of CaF2 and CaF2 + 0.34 mol % YF3 using a precision sectioning technique. In pure CaF2 between 800 and 1300 °C, D = = 4.8×107 exp (—5.160 eV/kT) cm2/s. The effect of YF3 is to increase D at temperatures below 950 °C but the magnitude of the increase is much smaller than expected for a vacancy mechanism unless a binding energy between Y3+ ions and cation vacancies of >0.6 eV is assumed. It is shown that the results may correspond to diffusion via cation–anion vacancy pairs at all temperatures investigated. Die Diffusion von 45Ca wird in CaF2- und CaF2 + 0,34 Mol%-YF3-Einkristallen unter Benutzung einer Abschleifmethode gemessen. In reinem CaF2 erholt man zwischen 800 und 1300 °C D = 4,8×107 exp (—5,160 eV/kT) cm2/s. YF3-Dosierung erhoht D bei Temperaturen unterhalb 950°C, jedoch ist die Grosenordnung der Erhohung fur den Leerstellenmechanismus viel geringer als erwartet, es sei denn, es wird eine Aktivierungsenergie zwischen Y3+-Ionen und Kationenleerstellen von >0,6 eV angenommen. Es wird gezeigt, das die Ergebnisse fur die untersuchten Temperaturen einer Diffusion uber Kationen–Anionen-Leerstellenpaare entsprechen.

The specimens from total laryngectomy performed in 70 patients were studied using the step-serial whole organ sectioning technique. Transverse histologic sections were taken and examined for minimum tumor clearance. The clinical status of patients for at least 4 years of observation was correlated with microscopic clearance of margins. The actual presence of tumor at the margins of resection was found in 21 (30%) of the specimens. The tumor was found to reach within 1 mm, 2 mm, and more than 2 mm from the margins in nine (13%), four (6%), and 36 (51%) specimens, respectively. The anterolateral margin was most commonly involved (19%), followed by the posterolateral (11%), postcricoid (7%), and upper (1.4%) margins. Local recurrence was found to be related to degree of clearance as 10 of 21 (48%) patients with no clearance and one of nine (11%) with 1 mm clearance had local failure. None of the patients with 2 mm clearance or more developed local recurrence. It is concluded that step-serial whole organ sectioning is an adequate method for thoroughly examining resection margins in laryngectomy specimens.

Using the tracer-standard sectioning technique the impurity diffusion of indium in copper has been investigated in the temperature range from 798.1 to 1081.0°C. For the frequency factor and the activation energy, respectively, the following values were determined: D02 = 1.87 cm2 · s−1; Q2 = 2.034 eV. The results are compared with predictions of theoretical models of the impurity diffusion in metals. Mit Hilfe der Tracer-Standardschichtenteilungstechnik wurde die Fremddiffusion von Indium in Kupfer im Temperaturbereich von 798,1 bis 1081,0°C untersucht. Fur den Frequenzfaktor bzw. die Aktivierungsenergie wurden folgende Werte ermittelt: D02 = 1,87 cm2 · s−1; Q2 = 2,034 eV. Bei einem Vergleich der Ergebnisse mit theoretischen Modellen fur die Fremddiffusion in Metallen zeigt sich eine gute Ubereinstimmung zwi-Theorie und Experiment.

The diffusion of 68Ge in single crystals of high-purity (over 99.99% pure) Ni has been measured using the sectioning technique. The plot of log D versus 1/T is straight from 939 to 1675K, over 61/2 orders of magnitude in D, with parameters D0=2.10+or-0.47 cm2 s-1, Q=2.74+or-0.03 eV (264+or-3 kJ mol-1). The data suggest a low Ge-vacancy binding enthalpy for Ni.

The grid sectioning technique has been used to obtain the two missing principal axis projections of orthorhombic catalase platelets and to measure directly the unit cell c-value. The negatively stained platelets have a unit cell c-dimension of half that proposed by Unwin (1975) from powder X-ray diffraction. The precision of the grid sectioning technique in positioning sections along a specimen axis shows that the growth fault lines usually observed on negatively stained catalase platelets are rows of missing molecules filled with stain. From these sections conclusions are drawn concerning the action of negative stain on a specimen, the microtomy process, and the specimen/supporting film interaction. Finally the value of microtomy for detailed structural analysis of biological objects is emphasized.

A study has been made of the diffusion of zinc, from a vapour source, into GaAs slices which had been previously implanted with various ion species. A radiotracer sectioning technique was used to measure the zinc diffusion profiles. It was found that the various implanted ion species (H+, He+, N+, Zn+, As+) had different effects on the zinc diffusion. The results could not be attributed solely to native defects produced by radiation damage. The heavier ion species increased the zinc concentration in the implanted region, but not beyond. The lighter species substantially increased the zinc diffusion rate and altered the resultant concentration profiles. Uphill diffusion was seen in slices which had been given a single high energy H+ implant. The results obtained are compared to those of Radiation-Enhanced-Diffusion experiments. It is suggested that the rate of incorporation of dopant species into the host semiconductor lattice is an important influence on the diffusion mechanism and the shape of the concentration profile.

In a series of 80 consecutive mastectomies it was investigated histologically, by a horizontal sectioning technique, how often the nipple and/or areola were involved in breast cancer. Such involvement was found in 35 cases (43.8%). In the same series the value of the clinical findings as to involvement of the nipple and/or areola was assessed. Only 6 of the 35 cases had shown clinical changes that could give rise to a suspicion of spread to the nipple and/or areola.

Tracerdiffusion coefficients of Ni2+ and Ga3+ have been measured in Ni 1− y Ga 2+2 y 3 O 4 spinel solid solutions at 1585°C in air using a standard sectioning technique. The results are in good agreement with theoretical considerations assuming a vacancy mechanism for diffusion in the cation deficit region (y > 0) while both the vacancy and the interstitial mechanisms are operating within the range of cation excess (y

Self-diffusion of 35S labelled molecules in highly perfect single crystals of orthorhombic sulphur has been studied by the serial sectioning technique. Measured lattice self-diffusion coefficients are considerably lower than those previously published for this solid. This difference is believed to be a consequence of a significant contribution from diffusion along dislocations in the crystals used in the previous study. Self-diffusion perpendicular to the [001] direction can be represented by an equation of the form D=2 × 1013exp[-(215±11 kJmol−1)/RT]m2s−1. Self-diffusion coefficients in the [001] direction are 2–4 times lower. This distinct anisotropy is probably a consequence of the marked structural anisotropy of this phase of sulphur.

The diffusion of Fe2+ ion in AgCl has been found to proceed substitutionally over the temperature range of measurement (232 to 449 °C). The standard serial sectioning technique was used. The temperature dependence of the diffusion can be represented by D = 15.1 exp (−1.27/kT) cm2/s. If the activation enthalpy of migration for Fe2+ is taken as 0.6 eV, the association enthalpy is about 0.07 eV for Fe2+ vacancy complexes. On a trouve que la diffusion de l'ion ferreux dans le chlorure d'argent procede par substitution dans toute l'entendue de la mesure de temperature (232 a 449 °C). On a employe la technique courante du sectionnement en serie. On peut representer la dependence de temperature de la diffusion par D = 15,1 exp (−1,27/kT) cm2/s. Si on choisit 0,6 eV pour l'enthalpie d'activation de la migration pour Fe2+, l'enthalpie d'association est aux environs de 0,07 eV pour les complexes de vacance de l'ion ferreux.

A preserving histologic technique with paraffin-embedding for the processing of laryngeal specimens is described. Decalcification and dehydration are performed in vacuum without electrolytic or ultrasonic treatment. The thickness of the individual histologic sections is 5 μm. Processing of the larynx takes 3–4 1/2 weeks, depending on size. The significance of this technique in the histologic control of clinical diagnosis and/or high-resolution computerized tomography is pointed out.

The diffusion of Ce ions in AgCl has been measured by the tracer and serial sectioning technique. The temperature dependence of the diffusivity follows a linear Arrhenius law with parameters D 0 =1.10×10 −3 cm 2 /s and H =0.62 eV. It appears that Ce enters the lattice as +3 ion in substitutional sites and diffuses as an associated complex with cation vacancies. The results of the study of eiectrical conductivity of the pure and Ce-doped AgCl supports this general view. Alternate possibilities are also discussed.

An inexpensive and simple technique is described to collect and section undisturbed core samples of wetland rice soil that can be used for research.

The diffusion of antimony in fine-grained and coarse-grained polycrystalline silicon is studied in the temperature range from 930 to 1150 °C. The radioisotope 125Sb is used to measure concentration-depth profiles with the sectioning technique. Autoradiography is used for making the lateral distribution of the radioactivity over the sample surface visible and for quantitative analysis of the activity-depth profile of distinct grains in the coarse-grained samples. An important role is played by dislocation formation during the diffusion anneal. Die Diffusion des Antimons im feinkornigen und grobkornigen polykristallinen Silizium wird im Temperaturbereich von 930 bis 1150 °C untersucht. Das Radioisotop 125Sb wird in der “sectioning”-Technik fur die Bestimmung der Tiefenprofile der Aktivitat verwendet. Autoradiographie wird benutzt zur Sichtbarmachung der Verteilung von Radioaktivitat uber die Oberflache und fur die quantitative Analyse des Tiefenprofils von bestimmten Kornen in grobkornigen Proben. Die Entstehung von Versetzungen wahrend der Diffusionsheizung spielt eine wichtige Rolle.

A study is made on the diffusion of Ga into bare and oxide-covered Si by using a closed capsule technique. The diffused wafers are analysed by an anodically sectioning technique. It is found that when the temperature of oxidation (Tox) is greater than that of diffusion (Tdiff), the effect of the oxide layers is to enhance the diffusion and in the opposite case when To, is less than Tdiff, the diffusion is retarded due to the oxide. However, when To, is equal to Tdiff, there is little or no effect due to the oxide. These results are explained in terms of the stress at the Si/SiO2, interface and the resulting strain gradient in bulk Si. Es wird die Diffusion von Ga in unbedecktes und oxidbedecktes Si in geschlossener Ampulle untersucht. Die diffundierten Scheiben werden mittels anodischer Sektionstechnik analysiert. Es wird gefunden, das bei hoheren Oxidationstemperaturen (Tox) ale die Diffusions temperature (Tdiff) die Oxidschicht die Diffusion erhoht und im entgegengesetzten Fall, wenn Tox kleiner als Tdiff ist, die Diffusion infolge des Oxids verzogert wird. Wenn jedoch Tox gleich Tdiff ist, gibt es keinen oder nur einen geringen Einflus durch das Oxid. Diese Ergebnisse werden mit Spannungen an der Si/SiO2-Grenzflache und des resultierenden Verzerrungsgradienten im Si-Volumen erklart.

Self diffusion of 48V in vanadium single crystals was reinvestigated over the temperature range 724–1842°C. Contribution to diffusion from migration along short-circuit paths at the lower temperatures was avoided by applying a micro sectioning technique specially developed for this study. The change in slope of the Arrhenius curve reported to occur at about 1350°C was not observed in this investigation, but has been observed to occur in the vicinity of 1642°C. The data in the temperature range 724–1642°C can be fitted to the relation consistent with normal diffusion by a single-vacancy mechanism. Above 1642°C the data fit the equation

By a combined anodizing and stripping technique, thin sections can be removed from vanadium metal. A uniform, thin oxide film can be grown on the vanadium metal in an acetone-benzoic acid-sodium tetraborate solution during anodization, which is then removed in aqueous NH4OH (10%). The thickness, x, of the metal removed in angstrom units is given by x= 103.2 + 12.5 V, V being the voltage applied. The application of such a sectioning technique for constructing penetration profiles in diffusion studies is of special interest, since contribution from diffusion along lattice defects can be recognized and eliminated. This paper considers the details of the experimental technique by which the films are grown and stripped.

By means of a microtome sectioning technique, lattice diffusion at 343 K of β-naphthol-8 14 C into naphthalene single crystals has been measured in two directions. The results reveal the existence of a molecular diffusion anisotropy: D a =(12.3±0.4)•10 −17 M 2 s −1 D c' =(4.3±0.5)•10 −17 m 2 s −1 La diffusion reticulaire de 8 14 C β-naphtol dans le naphtalene monocristallin a ete mesuree par la methode de sectionnement comptage dans 2 directions cristallographiques differentes. Les resultats font la preuve de l'existence d'une anisotropie de diffusion moleculaire a 343 K: D a =(12,3±0,4(•10 −17 m 2 s −1 D c' =(4,3±0,5)•10 −17 m 2 s −1

A novel sectioning technique for making serial sections for use in descriptive embryology is presented. This technique allows one to obtain good-quality sections (5- to 10-μm thick) of embryos embedded in plastic, several times faster than with conventional plastic sectioning techniques. Furthermore, this technique can be used to serially section embryos until desired levels are reached. One-micrometer or thin (50–100 nm) sections can then be cut for study, respectively, by light and transmission electron microscopy. The resolution of cellular morphology in 5- to 10-μm sections is intermediate to that of paraffin and 1-μm plastic sections, and gross tissue distortions typically present in paraffin sections are absent in plastic sections. Thus, in terms of convenience and section quality, this technique bridges the gap between those routine techniques used for preparation of conventional paraffin and plastic serial sections.

The diffusion profiles of iron have been very accurately measured in polyacetylene films, during their doping process with FeCl 3 , by using a radioactive isotope and a sectioning technique. Both in-diffusion from a labelled solution and out-diffusion towards an inactive solution have been studied. Saturation by thes dopant occurs at the mole fraction of 0.055. The crucial importance of the flow of dopant between the fibers is demonstrated. The rate of the isotopic exchange reaction is surprisingly high for a solid state reaction. These new data provide a better understanding of the doping mechanism.

Self- and gold-impurity diffusion measurements over the temperature range 850 to 1265 K are made on platinum single crystals using 197Pt and 199Au as radioactive diffusants and ion-beam sputtering as a sectioning technique. Gaussian penetration profiles are observed for well-annealed crystals. The influence of plastic deformation on the penetration curve is investigated and found to be considerable. The diffusivities obtained from well-annealed crystals fit the Arrhenius relations DPt = 0.05 exp (−2.67 eV/kT) cm2 s−1 for Pt self-diffusion and DAu = 0.13 exp (−2.61 eV/kT) cm2 s−1 for diffusion of Au in Pt. In conjunction with the high-temperature data of Kidson and Ross the present self-diffusion data are analysed in terms of mono- and divacancy contributions. For the sum of the enthalpy of formation and motion of a single vacancy a best value of 2.69 eV is deduced. The present Au-data close a gap since bulk diffusion measurements of Au in Pt are not available in the literature. Diffusion in the PtAu-system is important in semiconductor technology because of the frequent use of PtAu metallizations. Messungen der Diffusion von 197Pt und 199Au in Platineinkristallen werden im Temperaturbereich von 850 bis 1265 K mit Hilfe der Ionenstrahlzerstaubung als Schichtabtragetechnik durchgefuhrt. An gut ausgegluhten Kristallen werden Gaussche Eindringprofile beobachtet. Der Einflus plastischer verformung auf die Eindringkurve wird untersucht und erweist sich als betrachtlich. Die Diffusionskoeffizienten der gut ausgegluhten Kristalle werden durch die Arrhenius-Beziehungen DPt = 0,05 exp (−2,67 eV/kT) cm2 s−1 bei der Selbstdiffusion von Pt und DAu = 0,13 exp (−2,61 eV/kT) cm2 s−1 bei der Diffusion von Au in Pt beschrieben. In Verbindung mit den Hochtemperaturdaten von Kidson und Ross werden die Selbstdiffusionsdaten im Hinblick auf Einfach- und Doppelleerstellenanteile analysiert. Dabei ergibt sich fur die Summe aus Bildungs- und Wanderungsenthalpie der Einfachleerstelle ein bester Wert von 2,69 eV. Die Golddaten dieser Arbeit schliesen eine Lucke, da Messungen der Volumendiffusion von Au in Pt in der Literatur nicht vorhanden sind. Die Diffusion im PtAu-System ist in der Halbleitertechnologie von Bedeutung wegen der haufigen Verwendung von PtAu-Metallisierungen.

The microanatomy of vagal body paraganglia (VBP) in the cephalic segment of both vagus nerves was evaluated in an autopsy study of 32 infants one year of age or younger. The study group included 14 victims of sudden infant death syndrome (SIDS) and 18 non-SIDS cases. VBP in both groups were located at or below the lower border of the ganglion nodosum, and were histologically identical to carotid body chemoreceptors, although spatially dispersed and much smaller in size. Using a combined step and serial sectioning technique, there were no significant differences between the two groups (i.e. SIDS vs. non-SIDS) with regard to microanatomy, number, distribution and size of VBP. The proportion of chief and sustentacular cells was similar to carotid body paraganglia. For the study group as a whole, VBP were present in 89% of vagus nerves, and were typically multiple with good correlation between the number of separate paraganglia on the two sides. Small collections of ectopic parathyroid chief cells were identified in 6% of nerve segments, and histologically should be distinguished from VBP. Although the microanatomy of VBP in the SIDS group was identical to that of non-SIDS, one cannot exclude an underlying functional abnormality with autonomic malregulation.

The commonly employed methods of sectioning lymph nodes can account for a greater than 30% false pathologic interpretation when studying nodes for the presence of tumor. The failure to identify a tumor within a lymph node is related to the size of the lymph node, size of the lesion, number of sections examined, and the location of the tumor within the node. Analysis of these variables is approached by applying mathematical and computer formulation to numerous model nodes containing lesions of variable size and location. The percentage probabilities of identifying various sized lesions in different sized nodes is calculated in graphic form. These studies propose a functional method of lymph node sectioning which is applicable to improved sectioning technique.

Diffusion and Solubility of Cr51 in Silver Single Crystals investigated in the temperature range 976 to 1231 K using the serial sectioning technique. Solubility Xcr and diffusion coefficient D can be described by the following temperature functions: Xcr = exp [−1.76 ± ± 0.02) eV/kBT] and D = exp [−(2.00 ± 0.02) eV/kBqT] cm2 8−1. At the melting point the solubility of chromium is as small as 100 ppm. The results of the chromium diffusion cannot be explained in terms of the current models of impurity diffusion. Im Temperaturbereich zwischen 976 und 1231 K werden die Diffusion und die Loslichkeit von Cr51 in Silbereinkristallen mit Hilfe der Sektionsmethode untersucht. Loslichkeit Xcr und Diffusionskoeffizient D konnen durch die folgenden Temperaturfunktionen beschrieben werden: Xcr = exp [−(1,76 ± 02) 0v/kBT] und D = exp [−(2,00 ± ± 0,02) ev/kBT] cm2 s−1. Am Schmelzpunkt betrugt die Loslichkeit von Chrom lediglich 100 ppm. Die Ergebnisse der Chromdiffusion in Silber stehen nicht im Einklang mit den bekannten Fremddiffusionsmodellen.

The diffusion of Ni-63 and Sb-124 is measured on single crystals of Ni53Sb47 by the sectioning technique. Diffusion coefficients for transport parallel and perpendicular to the crystallographic c-axis (D‖ and D⟂) and activation energies are reported. The dependence of D on composition is studied on polycrystalline samples of Ni53Sb47 and Ni50Sb50. For Ni a mechanism in which Ni atoms migrate between double tetrahedral interstices and vacancies of the Ni sublattice is proposed. The effect of composition on DNi is explained by structural vacancies of the Ni lattice. D⟂/D‖ ratios point to a vacancy mechanism for diffusion of Sb. An Einkristallen von Ni53Sb47 wird mit Hilfe der Abschleifmethode die Diffusion von Ni-63 und Sb-124 untersucht. Diffusionskoeffizienten fur die Richtung parallel und senkrecht zur kristallographischen c-Achse (D‖ and D⟂) werden angegeben. Die Konzentrationsabhangigkeit von D wird an polykristallinen Proben der Zusammensetzungen Ni53Sb47 und Ni50Sb50 untersucht. Fur Ni wird ein Diffusionsmechanismus vorgeschlagen, bei dem das Ni Atom zwischen Doppeltetraederlucken und Leerstellen des Ni Teilgitters hin und her springt. Der beobachtete Konzentrationseinflus wird bei DNi mit Hilfe struktureller Fehlstellen des Ni Teilgitters erklart. Das D⟂/D‖ Verhaltnis weist auf einen Leerstellenmechanismus bei der Diffusion des Sb Atoms hin.

We examined the effect of three methods of porewater extraction on the measured concentrations of seven porewater constituents in vegetated salt marsh sediments. Porewater extraction by standard core sectioning followed by squeezing or centrifuging was compared with two less destructive methods of water collection. The core sectioning technique significantly increased the concentration of total dissolved organic carbon and dimethylsulfide presumably due to root damage by cutting. Sampling technique did not appear to influence interstitial salinity or concentrations of dissolved inorganic carbon, dissolved ammonium, soluble sulfides, and dissolved sulfate as long as proper precautions were taken to prevent the loss of reduced compounds.

Results of measurements between 533 and 1093 °C of the diffusion coefficient of Fe59 in two single crystals of FeSi (7.64 and 11.1 at% Si, respectively) are presented. For the lower temperatures a newly developed chemical sectioning technique was employed. The results show a marked ferromagnetic effect, i.e. the activation energy is strongly peaked at the Curie temperature. The results are analysed in terms of the Zener-LeClaire theory in combination with an argument that relates the enthalpy of vacancy formation with the change in magnetic specific heat of the matrix upon introduction of a vacancy. The latter argument can also be used exclusively when related to the introduction of an activated complex in the matrix. Es werden die Ergebnisse von Messungen des Diffusionskoeffizienten von Fe59 in zwei Einkristallen von Fe–Si mit 7,64 bzw. 11,1 At% Si im Temperaturbereich zwischen 533 und 1093 °C mitgeteilt. Die Messungen erfolgten oberhalb 700 °C nach der Schichtenteilungsmethode und unterhalb nach einer neu entwickelten chemischen Methode. Die Ergebnisse zeigen einen starken Einflus des Ferromagnetismus, d. h. die Aktivierungsenergie verandert sich im Bereich der Curie-Temperatur stark. Die Ergebnisse werden anhand der Zener-LeClaire-Theorie analysiert. Hinzugenommen wird der Einflus, den die Anderung des magnetischen Anteils der spezifischen Warme bei Bildung einer Leerstelle auf deren Bildungsenthalpie hat. Auserdem wird die Anderung der Curie-Temperatur durch das Auftreten von aktivierten Komplexen in der Matrix abgeschatzt.