bluuebunny/crossref_metadata_2025 huggingface dataset:
New Drugs Approved by the FDA; New Dosage Forms and Indications Approved by the FDA; Agents Pending FDA Approval; New Drug/Biologics License Applications Filed by Manufacturer; Supplemental Applications Filed by Manufacturer; Significant Labeling Changes or “Dear Health Professional” Letters Related to Safety
Authors: Baker Danial E.
Published: March 2011

This monthly feature will help readers keep current on new drugs, new indications, dosage forms, and safety-related changes in labeling or use. Efforts have been made to ensure the accuracy of this information; however, if there are any questions, please let me know at bakerdan@wsu.edu .
Pharmacist Project Management for Implementation of Electronic Health Records
Authors: Fox Brent I. , Felkey Bill G.
Published: March 2011

Eligible hospitals can now register for the Medicare electronic health record (EHR) incentive program. You are likely hearing more talk about developing an EHR implementation plan in your institution. In this issue, we describe the project management life cycle in the context of EHR implementation, with a focus on opportunities for pharmacists to be involved in EHR projects.
Recent Publications on Medications and Pharmacy
Authors: Russett Flint
Published: March 2011

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.
Clustering of additional autoimmunity behaves differently in Hashimoto's patients compared with Graves' patients
Authors: Wiebolt J , Achterbergh R , den Boer A , van der Leij S , Marsch E , Suelmann B , de Vries R , van Haeften T W
Published: March 2011

Objective

It is unclear whether Hashimoto's thyroiditis and Graves' disease (often referred to as autoimmune thyroid disease, AITD) cluster to the same extent with other autoimmune disorders.

Methods

We assessed adrenal, β-cell, celiac and gastric antibodies in a cohort of 523 adult patients with Graves' disease and 359 patients with Hashimoto's disease and compared their clustering.

Results

Adrenal autoimmunity associated more often with Hashimoto's disease (9.0%) than with Graves' disease (3.3%, P=0.001). β-cell autoimmunity was seen more frequently in Hashimoto's disease (25.4%) than in Graves' disease (15.6%, P=0.001) patients. We found low prevalences of celiac autoimmunity (1.2% for Graves' and 1.2% for Hashimoto's disease). Celiac and gastric autoimmunity were not statistically different in Hashimoto's and Graves' disease patients. Although gastric autoimmunity itself was equally prevalent (around 20%), Hashimoto's disease often showed significantly more clustering of adrenal autoimmunity with gastric autoimmunity (5.3%) than Graves' disease (1.2%, P=0.001). Similarly, clustering of adrenal autoimmunity was seen with β-cell autoimmunity in Hashimoto's patients (3.2%), while such clustering was much less encountered in 359 Graves' patients (0.9%, P=0.029).

Conclusion

In conclusion, Hashimoto's disease shows a markedly higher clustering of additional autoimmunity, especially with adrenal and β-cell autoimmunity. Combined clustering of gastric and adrenal autoimmunity and combined clustering of adrenal and β-cell autoimmunity were both seen more often in Hashimoto's patients. Clustering with celiac disease appears to be low. These findings indicate that Hashimoto's and Graves' disease differ in their clinical expression regarding additional autoimmunity, which argues against the indiscriminate use of AITD as an entity.
Metabolic and cardiovascular outcomes in a group of adult patients with Turner's syndrome under hormonal replacement therapy
Authors: Giordano Roberta , Forno Daniela , Lanfranco Fabio , Manieri Chiara , Ghizzoni Lucia , Ghigo Ezio
Published: March 2011

Objective

Turner's syndrome (TS) is a rare genetic disorder caused by complete or partial X chromosome monosomy in a phenotypic female, and it is associated with increased morbidity and mortality for cardiovascular diseases, impaired glucose tolerance, and dyslipidemia.

Subjects and methods

In 30 adult TS patients under chronic hormonal replacement therapy (HRT), 17β-estradiol (E2), body mass index (BMI), waist circumference, fasting glucose and insulin, homeostatic model assessment (HOMA) index, serum lipids, oral glucose tolerance test (OGTT), 24 h ambulatory blood pressure monitoring (ABPM), and intima–media thickness (IMT) were evaluated and compared with those in 30 age- and sex-matched controls (CS).

Results

No difference was found between TS and CS in E2and BMI, whereas waist circumference was higher (P<0.05) in TS (77.7±2.5 cm) than in CS (69.8±1.0 cm). Fasting glucose in TS and in CS was similar, whereas fasting insulin, HOMA index, and 2 h glucose after OGTT were higher (P<0.0005) in TS (13.2±0.8 mUI/l, 2.5±0.2, and 108.9±5.5 mg/dl respectively) than in CS (9.1±0.5 mUI/l, 1.8±0.1, and 94.5±3.8 mg/dl respectively). Total cholesterol was higher (P<0.05) in TS (199.4±6.6 mg/dl) than in CS (173.9±4.6 mg/dl), whereas no significant differences in high-density lipoprotein, low-density lipoprotein, and triglycerides were found between the two groups. In 13% of TS, ABPM showed arterial hypertension, whereas IMT was <0.9 mm in all TS and CS. A negative correlation between insulin levels, HOMA index, or 2 h glucose after OGTT and E2was present in TS.

Conclusions

Our results indicate that adult patients with TS under HRT are connoted by higher frequency of central obesity, insulin resistance, hypercholesterolemia, and hypertension.
Dysmotility-type dyspepsia and eructation. Introduction of a new gas-analytical method
Authors: Nagy Éva , Bálint Mária , Udvarhelyi László , Szilvás Ágnes
Published: March 2011

This paper describes a new gas-analytical method used in a 55-year-old female patient with dyspepsia. Symptoms included epigastric fullness and inflation. Evaluation indicated an increased gas production in the proximal end of the small intestine that entered into the stomach via duodenogastric reflux. High CO2 content of eructed gas was confirmed in eructed gas samples using a tube in situ. Authors propose that this new analytical method of eructed gas may be applied in clinical practice in patients with dyspepsia. Orv. Hetil., 2011, 152, 443–446.
Molecular genetic diagnosis of neurofibromatosis type I
Authors: Polgár Noémi , Komlósi Katalin , Hadzsiev Kinga , Illés Tamás , Melegh Béla
Published: March 2011

Type 1 neurofibromatosis is an autosomal dominant hamartosis, caused by mutations of the gene neurofibromin-1. The variable clinical phenotype is characterized by café-au-lait spots, benign neurofibromas, axillary, inguinal hyperpigmentations, iris hamartomas, skeletal deformities and risk of neurofibroma-development. Pathogenic variations of neurofibromin-1 arise as de novo mutations in approx. 50% of the cases. Aims: Molecular genetic testing of neurofibromin-1 gene has been performed in our department since 2008; the following report summarizes our experiences. Methods: 40 patients, presenting symptoms of type 1 neurofibromatosis, were screened by sequencing or multiplex ligation-dependent probe amplification. Results: Pathogenic alterations were identified in 31 cases, 8 patients presented novel mutations. In 8 affected, no mutations were detected by sequencing; one of these patients had a deletion affecting the entire gene. Conclusions: Sequencing of the neurofibromin-1 gene and screening for rearrangements are useful in identifying pathogenic alterations in most of the cases. Orv. Hetil., 2011, 152, 415–419.
Low Thermal Expansion Polyimides and their Applications
Authors: Numata Shunichi , Miwa Takao , Misawa Yutaka , Makino Daisuke , Imaizumi Junichi , Kinjo Noriyuki
Published: March 2011

Thermal expansion coefficients (TECs) for polyimides differ very much depending on their chemical structures. Polyimdes with a rod-like structure as their backbone chains have lower TEC values. This is attributed to restraining of thermal expansion by rod-like molecules within intermolecular spaces, analogous to glass fibers in FRPs. The development of new polyimides which can closely match TECs of inorganic materials, such as metal or Si, can eliminate problems produced by thermal stress including warping, cracking or delamination.

A new multilevel interconnection system using multilayered dielectrics consisting of low thermal expansion polyimide and inorganic materials has been proposed as one future technology for submicron VLSIs. Consequently, adhesiveless, high quality flexible printed circuit boards have been developed using a polyimide with the same TEC as copper foil. Their most significant property is a high dimensional stability after heat treatments, such as in a soldering process. Furthermore, they have very high adhesion strength at elevated temperatures.
Materials Limitations in the Higher Electronic Packaging Levels
Authors: Neugebauer C. A.
Published: March 2011

Microminiaturization is desirable for reasons of lower cost, lower volume and weight, higher performance, and higher reliability. Microminiaturization is best achieved by downscaling the feature sizes on the chip itself, and this indeed continues to be the major driving force in the electronics revolution. It is normally cheaper, weighs less, is faster, and is more reliable to put as much of a system's interconnection effort on the chip itself (i.e., packaging level 0). Costs increase steeply for interconnections on the higher levels.
Materials for High Speed Circuit Boards
Authors: Seibold R. W. , Lamoureux R. T. , Goodman S. H.
Published: March 2011

During the past five years, the computer you bought with 128 Kbytes of memory has been upgraded by the availability of 40 Mbyte storage and modems which allow instant access to databases around the world. The continuing need to perform more complex missions for modern defense systems in more hazardous environments will call for substantially higher data rates than are available today.
Surface Migration of Low Molecular Weight Products Induced by Hygrothermal Fatigue in Epoxy Composites
Authors: Porto A. , Licciardello A. , Grasso D. , Cavallaro A. , Ferla G. , Puglisi O.
Published: March 2011

The hygrothermal fatigue induces a complex phenomenology in the epoxy composites, with degradation of the linear coefficients of expansion.

Epoxy composites, (novolac type, with SiO2 as filler, 75–85 % in weight) have been exposed to high temperature and high pressure moisture.

A role important is played by the decomposition products formed during the aging. The Molecular Weight Distribution of these species has been followed by GPC and shows that there is partial depolymerization of the matrix after 24 h treatment time. It has been found that there is surface migration of low Molecular Weight species, both additives and decomposition products.
Characteristics of Polyethylene Thin Films Deposited by Ionized Cluster Beam
Authors: Usui Hiroaki , Numata Kouji , Dohmoto Hitoshi , Yamada Isao , Takagi Toshinori
Published: March 2011

Polyethylene thin films were deposited by the ionized cluster beam (ICB) method. The dielectric, resistivity, and breakdown field measurements showed that the ICB polyethylene films have excellent properties as an electrical insulator. The characteristics of Au/polyethylene/Si MIS diodes and MISFErs indicated that the ICB method can control the film-substrate interface property. The SIMS and ESCAan alyses showed that the ICB films have pure and stable chemical structure.
Polymer Encapsulated Microelectronics: Mechanisms of Protection and Failure
Authors: Anderson J. E. , Markovac V. , Troyk P. R.
Published: March 2011

This research relates electrochemical failure of encapsulated microelectronics to surface moisture and to surface impurities. It draws heavily on “osmotic blistering”, a phenomenon known to produce corrosive failure of coated/painted metals [1].

Leakage currents were measured on aluminum comb specimens as a function of relative humidity (RH) and temperature. We studied both bare combs and combs encapsulated with polysiloxane. 9.05 Vdc bias was used. We performed “contamination-by-design” experiments by deliberately introducing known amounts of NaCl, CaCl2 and sucrose onto the comb surface. Results were compared with corresponding data taken on well-cleaned specimens.

Our principal findings are

(1) Under dry conditions (RH<1%), small leakage currents are observed, ranging between 1-10 pA, which are insensitive to surface contamination levels. This implies that solid surface impurities Rer se do not promote electrochemical IC failure.

(2) In extremely moist environments (RH>99%), surface-contaminated samples exhibit large leakage currents, ranging between 1 and 10 pA, that are roughly proportional to surface loading.

(3) Different surface chemical compounds produce leakage-current steps at specific RH values, corresponding to solid-to-saturated solution transitions. For example, CaCI2 exhibits a transition at 21% RH; NaCl at 75% RH. At RH values above the transition, aqueous droplets, or vacuoles, were observed at surface sites occupied by solid deposits. The RH location of the transitions is largely unaffected by the presence or absence of polymer encapsulant. Leakage current steps were typically four to six orders of magnitude. The size of the step change varied between bare and encapsulated samples, and with surface loadings.

(4) Variable temperature studies, performed at constant external water vapor, exhibited step decreases in leakage current at temperatures corresponding to saturated solution to solid transitions.

(5) Sucrose, a nonelectrolyte, exhibited a leakage current step similar to those observed with CaCl 2 and NaCl. The size of the sucrose step change was significantly less than that observed with the electrolytes.

(6) Electrochemical attack patterns varied among the different chemical compounds. For example, as shown in Fig. i, CaCl 2 exhibited anodic attack on alternate metallization lines. NaCl produced attack on all metallization lines.

A full report of this work will appear elsewhere [2].
XPS Studies of Chromium Atoms Interacting with a PMDA-ODA Polyimide Surface
Authors: Haight R. , Silverman B. D. , White R. C. , Ho P. S. , Rossi A. R.
Published: March 2011

XPS data obtained during the initial stages of vapor deposition of chromium atoms onto a PMDA-ODA polyimide substrate is presented. Utilizing the results of molecular orbital calculations it is emphasized that the data is consistent with the formation of a charge transfer complex between the deposited metal atoms and the PMDA unit of the polymer.
The Promotion of Metal/Polymer Adhesion by Ion Beam Enhanced Deposition
Authors: Loh Ih-Houng , Hirvone J. K. , Martin J. R. , Revesz P. , Boyd C.
Published: March 2011

The adhesion between metals and polymers is normally weak because they have drastically different electronic properties and interfacial bonding between metals and organic polymers is not readily affected by conventional coating techniques. The ion beam enhanced deposition (IBED) approach to improve adhesion focuses on the promotion of non-equilibrium “interdiffusion” and the creation of nucleation sites at the interfaces by low energy ion bombardment before and during metal deposition onto the polymer substrate.

The results of our work show a significant improvement of adhesion at the metal (Au)/polymer (Teflon) interface.
Hydrogen Diffusion Between Plasma-Deposited Silicon Nitridepolyimide Polymer Interfaces
Authors: Nguyen Son Van , Kerbaugh Mike
Published: March 2011

A Nuclear Reaction Analysis (NRA) for Hydrogen technique was used to analyze the hydrogen concentration near Plasma Enchanced Chemical Vapor Deposition (PECVD) silicon nitride-polyimide interfaces at various nitride-deposition and polyimide-polymer-curing temperatures. The CF4 + O2 (8% O2) plasma-etch-rate variation of PECVD silicon nitride films deposited on polyimide appeared to correlate well with the variation of hydrogen-depth profiles in the nitride films. The NRA data indicate that hydrogen-depth-profile fluctuation in the nitride films is due to hydrogen diffusion between the nitride-polyimide interfaces during deposition. Annealing treatment of polyimide films in a hydrogen atmosphere prior to the nitride film deposition tends to enhance the hydrogen-depth-profile uniformity in the nitride films, and thus substantially reduces or eliminates variation in the nitride plasma-etch rate.
Materials and Processes At the Leading Edge of Photolithography
Authors: Taylor Gary N.
Published: March 2011

The evolution of optical lithography to higher resolution patterning with step-and-repeat exposure methods has resulted from the precise fabrication of higher numerical aperture lenses, more precisely engineered and controlled mechanical and electrical subsystems, and new lenses, systems components and light sources which enable efficient printing at shorter wavelengths. Optical resist technology is undergoing a parallel evolution which is sharpening this capability even further. This paper outlines resist materials and processes at the leading edge of photolithography which will enable printing near and perhaps at the theoretical resolution limits. Subtopics discussed include resists sensitive to 248.4 nm excimer laser radiation, planarization methods, multilevel resist materials, and surface-functionalized plasma-developed resists. Finally, some conjecture about the practical resolution limits of optical lithography is presented.
Device Limitations
Authors: Keyes Robert W.
Published: March 2011

Packaging technology must deal with the inexorable trend of semiconductor technology towards higher levels of integration. Extrapolation of present trends suggests that chips with 100 million devices will be produced by the end of the present century. The ability of technology to miniaturize pin-outs will limit the utilization of all of these devices for purposes other than memory. This limitation plus problems of supplying power and removing heat means that chips for high-performance large systems, where the demand for pins follows a well known rule, will probably be limited to levels of integration less than 100,000. A model of large system wiring shows that large increases in the density of wires in system packages and in the rate at which heat can be removed will be needed.

Less severe limitations apply to low cost applications. No large increase in power per chip can be anticipated. However, more powerful microprocessors will become available and will need increased amounts of input-output capability.
Materials and Structures for High Density I/O Interconnection Systems
Authors: Hong S. , Bravman J. C. , Weihs T. P. , Kwon O. K.
Published: March 2011

In order to examine the use of a compliant cantilever structure as a contact scheme for a Multi-chip Interconnection System (MIS), multi-layer (metals and SiO2) cantilever beams were fabricated utilizing standard silicon processing and micromachining technologies. The mechanical behavior and electrical characteristics of the beams were investigated in order to establish their optimum dimensions for use in the MIS. During the course of this study, a new mechanical testing method for thin films has also been developed, which makes use of the same cantilever beam structure and a “Nanoindenter.” The Young's modulus and yield strength of thermally grown SiO2 and Au were measured using this technique.
A Study of Threshold and Incubation Behaviourduring Electromigration in thin Film Metallisation
Authors: Ross C. A. , Evetts J. E.
Published: March 2011

We have previously described a microstructural model for electromigration in thin film metallisation, based on the concept of a stress-driven backwards flux opposing the forwards electromigration flux. The model can be used to calculate the build-up of stress in a metallisation track subject to arbitrary variations in electromigration flux, and to predict both the location of electromigration damage and incubation times before its appearance. In this paper we present an experimental study of electromigration behaviour in thin aluminium films on a niobium substrate and relate the results obtained to the model.
Asymmetries in the Formation of Electromigration Damage Around Divergence Dipoles in a Metallization Track
Authors: Schwarzenberger A. P. , Greer A. L.
Published: March 2011

Electromigration damage mechanisms around lithographically introduced notches in unannealed and annealed test tracks are studied.
Mechanical Interconnects to Silicon Integrated Circuits
Authors: Steidel Charles A.
Published: March 2011

There are three predominant interconnection technologies in use today for silicon integrated circuits: wire bonding; TAB (tape automated bonding); and C4 (controlled collapse chip connection). This paper briefly reviews each of these technologies for their strengths and weaknesses but focuses especially on wire bonding for single chip VLSI applications.

Although wire bonding has been in widespread use ever since the invention of the small scale integrated circuit, the technique is still applicable for today's much larger and denser chips. With leadcounts up to 250 or even higher, many challenges are presented for equipment accuracy and speed and in package design, where novel techniques often are required to prevent the package from being the limiting factor in chip interconnection. These challenges are discussed in some detail.

The paper concludes with a discussion of the future direction for mechanical connections as influenced by the technical and cost requirements of both the chip and the system in which it resides.
Esca and Sims Study of the Tetrabromobisphenol A Flame Retardant Diffusion to the Metal-Encapsulating Resin Interface
Authors: Torrisi Alberto , Cavallaro Angelo , Perniciaro Antonio , Ferla Giuseppe , Pignataro Salvatore
Published: March 2011

Epoxy resins of novolac type were molded to real copper and nickel plated copper framesin plant conditions. Three resins, formulated with different amount of tetrabromobisphenol A flame retardant, were used. The samples were stored at 200°C and then mechanically fractured at given time intervals. The surfaces obtained in the fracture have been analyzed by ESCA and Ga+ excited static and imaging SIMS. The kinetics of migration of the flame retardant to the resinmetal interfacial zone have been followed. The process was found to be diffusion controlled. Evidence of a redox reaction between the copper oxides found on the surface of the copper frame and the tetrabromobisphenol A was obtained. A copper diffusion through the Ni plating was observed in the case of the nickel plated frames. This phenomenon is most important at the point on the frame where the bromine concentration is higher.
Lateral Diffusion of NIAL3 and NI2AL3
Authors: Liu Joyce. C. , Mayer J. W.
Published: March 2011

Phase formation of NiAl3 and Ni2Al3 were studied individually in lateral diffusion couples A and B and simultaneously in sample C. The lateral growth of certain phases was controlled by varying the thickness ratios of Al to Ni at the source and thin film area. Parabolic dependence of the phase width on annealing time was found for NiAl3 and Ni2Al3 in the one-phase and two-phase growth at 425 °C.
Thermodynamics of Wetting by Liquid Metals
Authors: Yost F. G. , Romig A. D.
Published: March 2011

The wetting of metal surfaces by molten solder is usually considered to be driven solely by an interfacial energy imbalance. The effect of chemical reactions on the wetting process is neglected, although the growth of an intermetallic layer in the wetted interface is commonly observed. In this work, the energy release during the incremental advance of a spreading solder droplet due to the interfacial energy imbalance and the formation of the intermetallic layer is calculated. The free energy of formation, ΔG, of the intermetallic layer is shown to be an important driving force for solder wetting.

This approach to wetting has been applied to three systems, Cu-Sn, Cu-Sb and Cu-Cd. Liquid Sn, Sb and Cd react with solid Cu to form Cu6Sn5 (η), Cu2Sb (γ) and CuCd3 (ε), respectively. The free energy of formation, ΔG, for these intermetallic compounds is unknown experimentally, but can be calculated from the phase diagrams and other solution data using classical thermodynamics. These thermochemical calculations yield ΔG(η) = 465–3.09T for Cu-Sn, ΔG(γ) = −2500+0.54T for Cu-Sb and ΔG(ε) = −825+0.44T for Cu-Cd (cal/mole). These relations were evaluated at the respective melting temperatures and compared with the interfacial energy exchange. In all three cases the ΔG contribution was approximately two orders of magnitude larger than the interfacial energy exchange making it the dominant driving force for wetting kinetics.
Microstructure Development in Thin Films During Deposition from the Vapor Phase
Authors: Goyal D. , King A. H. , Bilello J. C.
Published: March 2011

Transmission electron microscope observations of the structures of single-phase metallic thin films have been made. Films prepared by sputtering and by thermal evaporation have been used and the structures have been evaluated quantitatively as a function of film thickness. It is found that the grain size in all films increases linearly with the film thickness, indicating that grain growth occurs during film deposition.
Stresses in Anisotropic Thin Films Bonded to Stiff Substrates
Authors: Lambropculos John C. , Wan Shih-Ming
Published: March 2011

Numerical techniques are used to calculate the stress concentrations arising near the interface of a single-crystalline film which is bonded to a stiff substrate. The film has cubic elastic symmetry, and it is characterized by the anisotropic constants A and H which show the deviation of the material frcm elastic isotropy. The normal to the film-substrate interface is taken to be along the 100, 111 or 110 directions. The inhomogeneous stresses near the free edge and the uniform stresses far from the free edge are calculated, and the effects of cubic elastic anisotropy and of film growth direction are established for material parameters typical of metallic and semiconducting films.
Integrated Optoelectronic Materials and Circuits for Optical Interconnects
Authors: Hutcheson L. D.
Published: March 2011

Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs Integrated Optoelectronic Circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC's are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected.
Lithium Niobate Packaging Challenges
Authors: Murphy E. J. , Holmes R. J. , Jander R. B. , Schelling A. W.
Published: March 2011

The use of lithium niobate integrated optic devices outside of the research laboratory is predicated on the development of a sound packaging method. We present a discussion of the many issues that face the development of a viable, robust packaging technology. We emphasize the interaction of lithium niobate's physical properties with available packaging materials and technologies. The broad range of properties (i.e. electro-optic, piezo-electric, pyro-electric, photorefractive…) that make lithium niobate an interesting material in many device applications also make it a packaging challenge. The package design, materials and packaging technologies must isolate the device from its environment so that lithium niobate's properties do not adversely affect the device performance.
Thin Film Wiring for Integrated Electronic Packages
Authors: Wen Sheree H. , Kim Jungihl I.
Published: March 2011

Among the available packaging technologies, thin film wiring is most suitable for high density package applications. This paper discusses the materials choices for the thin film wiring and some possible fabrication processes. The Cu- polymer or Cu- glass system are most promising from both performance and manufacturability perspectives. The interface adhesion and high inter layer interconnection resistance are critical problems for this structure. The use of a Cr, Cu blend structure as an interface layer will solve this problem. The microstructure, interface chemistry and the adhesion mechanisms of this blend layer are discussed.
Microstructure and Physical Properties of New SiC Materials with High Thermal Conductivity
Authors: Shinozaki S. S. , Hangas J. , Maeda K.
Published: March 2011

Silicon carbide materials with BeO addition (2 wt%) have the unique properties of high electrical resistivity, high thermal conductivity, and a thermal expansion coefficient close to that of silicon. The materials have been used as a chip carrier material for high power LSI packaging. Microstructures were correlated by means of analytical electron microscopy (AEM), with the physical properties. Generally, BeO particles are evenly distributed mostly at triple points and the grain growth is anisotropic and many grains are elongated with an aspect ratio of 2 or 3. The average grain size is measured to be around 5 μm and the morphology is typically thick tabular.

AEM analysis has shown that large middle section of each SiC grain is mostly 6H polytype with a few or no stacking faults. On both sides of the 6H polytype, sheaths are formed, which consist of a large number of extremely thin 4H or other polytype lamellae. Along grain boundaries, no second phase formation is observed with a few exception of Be 2 C and impurity transition metal compounds lamellar formation.

The results indicate that direct and clean contacts between 6H lamellae and BeO grain or other 6H lamellae form a path of high thermal conductivity. On the other hand, complex network of thin disordered (4H rich) lamellae doped with BeO forms the electrically high resistive path.
Effect of Overpack Materials on Glass Leaching in Geological Burial
Authors: Werme Lars , Hench L. L. , Lodding Alexander
Published: March 2011

This is one of two papers discussing the findings in an in situ-burial experiment, presently being performed in the Stripa mine in Sweden. The purpose of the experiment is to evaluate the effects of various components in the SKBF/KBS waste storage system on the leaching of the vitreous waste form. Two configurations of glass, canister, overpack and buffer/backfill materials were designed (Figs. 1 and 2). Both configurations were inserted into 56 mm diameter boreholes in the Stripa mine and maintained at 90°C. One of the configurations (Fig. 2) was also kept at ambient temperature, 8°C. In the experiments two glass types were used, ABS 39 and ABS 41 (Table 1). These glasses, developed by Dr. T. Lakatos of the Swedish Glass Research Institute, contain 9% simulated fission products by weight and are compatible with the French AVM process.
Chemical Durability of Glass Containing Srp Waste - Leachability Characteristics, Protective Layer Formation, and Repository System Interactions
Authors: Wicks George G. , Robnett Barbara M. , Duncan Rankin W.
Published: March 2011

Leachability is one of the most important properties of solidified nuclear waste forms because it provides information on the performance and the subsequent safety and reliability that the waste products will possess. One of the most important experimental findings in the leachability field has been the discovery and subsequent detailed characterization of protective surface layers that form on waste glass during leaching. These layers can have a beneficial effect on product performance while in storage by improving productdurability with time. As a result of surface layer formation and the effects on subsequent product leaching characteristics, new qualitative and quantitative leaching models have recently been proposed.
Determination of the Corrosion Mechanisms of High-Level Waste Containing Glass
Authors: Scholze Horst , Conradt Reinhard , Engelke Heinrich , Roggendorf Hans
Published: March 2011

The German concept of high level waste final storage provides the use of certain glasses containing radioelement oxides as glass components. These waste forms are to be stored in rock salt formations in order to isolate the waste from the biosphere. The efficiency of this isolation is a most important question. The aim is to achieve a high safety standard that remains valid under extreme conditions such as the uncontrolled water entrance to the deposit.
Comparative Study of Seven Glasses for Solidification of Nuclear Wastes
Authors: Nogues J. L. , Hench L. L. , Zarzycki J.
Published: March 2011

The relative leaching behavior of seven alkali borosilicate glasses considered for immobilization of high level radioactive wastes was compared using a static 90°C leach test similar to MCC-l. All compositions (Table I) were compatible with the low melting temperature, 1150*C, viscosity and other process variables required for the French AVM process. The quantity of simulated waste products was from 10.9-15.9 weight %.
Characterization of Mechanical Properties of Nuclear Waste Glasses
Authors: Richter Herbert , Offermann Peter
Published: March 2011

Part of nuclear fuel cycle waste is highly dangerous, and must be safely isolated from people. Although the site of the final waste disposal must be the main safety barrier, the form of the waste and its properties are also important considerations.
Fracture Appraisal of Large Scale Glass Blocks Under Realistic Thermal Conditions
Authors: Laude Francis , Vernaz Etienne , Saint-Gaudens Michel
Published: March 2011

The compositions of borosilicate glasses used to solidify fission product solutions are selected for their low leach rates. Fracturing of the glass blocks, caused primarily by thermal and residual stresses during cooling, increases the potential leaching surface area and the number of small particles, both of which are undesirable since long term container failure must be considered. It is therefore important to know the state of fracture of the glass occurring at different stages of its thermal history. A theoretical appraisal of the fracture state of the glass is presented, complimented by an experimental study using industrial scale glass blocks under realistic thermal conditions.
An Attempt to Assess The Long-Term Crystallization Rate of Nuclear Waste Glasses
Authors: Jacquet-Francillon Noël , Pacaud FranÇois , Queille Pierre
Published: March 2011

The crystallization of fission product glasses is generally caused by maintaining these glasses at high temperatures (600° to 900°C) for several days or weeks in order to evaluate the effects of crystallization on leach resistance and mechanical properties.
Sims Depth Profiling Studies of Sphene-Based Ceramics and Glass Ceramics Leached in Synthetic Groundwater
Authors: Hayward P.J. , Hocking W.H. , Doern F.E. , Cecchetto E.V.
Published: March 2011

Glass ceramics and ceramics based on the mineral sphene (CaTiSiO5) are being developed to host the wastes arising from possible future CANDU* fuel reprocessing. Results from leaching tests in deionized water and in synthetic groundwater indicate that these materials are highly durable. Secondary Ion Mass Spectrometry (SIMS) depth profiling of leached specimens suggests that leaching in the glass ceramics is predominantly confined to the glass phase. The high ionic strength and composition of the groundwater have a significant passivating effect on leaching and surface alteration phenomena, and encourage the precipitation of new phases on the ceramic surface. Leaching results, scanning electron microscope (SEM) observations and SIMS depth profile measurements are compared and discussed.
A Study of Radiation Effects in Curium-Doped Gd2Ti2O7 (Pyrochlore) and CaZrTi2O7 (Zirconolite)
Authors: Wald J.W. , Offemann P.
Published: March 2011

Radiation effects studies in both glass and glass ceramic nuclear waste forms have identified a rare-earth titanate phase of the general formula (RE) 2Ti207 which is capable of acting as a host phase for actinides.1,2 Ringwood and co-workers3 have also proposed a structurally similar phase, zirconolite (CaZrTi2 07), as one of the primary host phases in the SYNROC waste form. Data from these and other previous studies, as well as mineralogical information available on these titanate phases, have not provided an unambiguous interpretation of the effects of radiation damage relative to nuclear waste forms. This paper reports new laboratory data concerning radiation damage effects in both of these phases.
Deformation-Dissolution Potential of Bedded Salt, Waste Isolation Pilot Plant Site, Delaware Basin, New Mexico
Authors: Anderson Roger Y.
Published: March 2011

Deep-seated collapse and brecciation is a feature common to bedded salt in a number of evaporite basins. The origin of these features is poorly understood. The relatively young geologic age of uplift and exposure of evaporites in the Delaware Basin, and a still-active hydrologic system, provides a unique opportunity to examine the pathways of water movement related to collapse features and salt dissolution. In addition, salt deformation structures are closely associated with brine, dissolution, and collapse. This report briefly discusses evidence for deep-seated dissolution,considers the relationship between deformation, dissolution, and brine, and examines the potential for dissolution at the WIPP (Waste Isolation Pilot Plant) site with respect to stages in the deformation-dissolution process.
Mineralogical and Geochemical Factors Influencing the Final Disposal of Hlw in the Stassfurt Halite
Authors: Gies Hermann
Published: March 2011

As the thickest and primarily monomineralic saline horizon in the Federal Republic of Germany, investigation of the Zechstein-2-Series, Stalfurt-Halite (Na2) is being emphasized for the final disposal of HLW. This horizon is of particular importance, especially since it is the base of the whole saline formation in northern Germany
The Importance of Near-Field Phenomena for Nuclide Release from a Flooded Salt Dome Repository
Authors: Storck Richard
Published: March 2011

Safety studies for final disposal of nuclear waste at the Gorleben site in Germany are performed by the project "Safety Studies Entsorgung (PSE)" supported by the Federal Ministry for Research and Technology. The ain of the project is to do consequence assessments for selected site-specific scenarios. The restriction to consequence assessments, instead of performing an overall risk assessment,is based on the expectation that the safety of a given repository site can be demonstrated by showing that the consequences of each scenario, which might reasonably occur, are acceptable.
Diffusion in the Matrix of Granitic Rock. Field Test in the Stripa Mine
Authors: Birgersson Lars , Neretnieks Ivars
Published: March 2011

A migration experiment with the objective to investigate the existence of a connected pore system in undisturbed rock has been performed in the Stripa mine at the 360 m-level.
A Flow Model for the Kinetics of Dissolution of Nuclear Waste Forms; A Comparison of Borosilicate Glass, Synroc and High-Silica Glass
Authors: Macedo Pedro B. , Barkatt Aaron , Simmons Joseoph H.
Published: March 2011

A model has been developed to predict the long-term leach or release rates of various waste-form materials under repository conditions.
Development of a Backfill for Containment of High-Level Nuclear Waste
Authors: Hodges Floyd N. , Westsik Joseph H. , Bray Lane A.
Published: March 2011

Sodium and calcium bentonites, pressed to densities between 1.9 and 2.2 g/cm3, have hydraulic conductivities in the range of 10−11 to 10−13 cm/s. Batch sorption distribution ratios (Rd) indicate that Sr, Cs, and Am are strongly sorbed on bentonites and zeolites, that Np and U are moderately sorbed on bentonites and zeolites, and that Am, Np, U, I, and Tc are strongly sorbed on charcoal. Sorption results with basalt and tuff ground waters are similar; however, iodine in tuff ground water sorbs more strongly on bentonites Thermal diffusivity measurements for dry, compacted (p ∼ 2.1 g/cm3) sodium bentonite indicate that the thermal conductivity of a high density bentonite backfill should be roughly similar to that of silicate host rocks (basalt, granite, tuff). These results indicate that a bentonite backfill can significantly delay the first release of many radionuclides into the host rock and that by forming a diffusion barrier a bentonite backfill can significantly decrease the longterm release rate of radionuclides from the waste package.
Analysis of the Corrosion Products Formed on Ti and a Ti-Pd Alloy During Exposure in Hot Water
Authors: Olefjord Ingemar , Mattsson HÅkan
Published: March 2011

This is a preliminary report dealing with the surface analysis of reaction products formed on Ti and a Ti-Pd alloy during their exposure in hot water. The compositions of the aqueous media were varied with respect to the dissolved oxygen and the content of chloride ions. The temperature was 60°C and the exposure times were 10 min. and 6 months. Work is in progress in which samples are exposed at 80°C and 95°C in the aqueous solutions. Surface analysis was also performed on a sample which had been exposed in water-saturated bentonite.

It appears from the ESCA spectra that the oxide products formed on the surface consist of TiO The results also indicate that the thickness of the film formed at 60°C in water is in the range 50 Å to 100 Å. This is somewhat more than that obtained after exposure in water at room temperature. Exposure for 6 months increases the thickness of the oxide two to three times compared to that obtained during the short exposure at 60°C. The analyses of the samples that had been embedded in bentonite indicate that the surface reaction products are thinner than those found on the surface after exposure in an open vessel.
Evaluation of Solubility and Speciation of Actinides in Natural Groundwaters
Authors: Schweingruber Marc R.
Published: March 2011

Groundwater circulation is in the long term probably the most important mechanism for the transport of radionuclides from deep underground repositories to the biosphere. The fate of leached long-lived nuclides, such as the actinides, is of particular interest to repository safety analysis. Both experimental and theoretical studies should lead to a comprehensive description of their behaviour in the geosphere.
Study of Radionuclide Migration from Deep-Lying Repository Sites with Overlying Sedimentary Layers
Authors: Hadermann Joerg , Roesel Fritz , Mccombie Charles
Published: March 2011

In Switzerland the host rock formations currently considered for disposal of high-level wastes lie in the northern part of the country. They form the crystalline basement and are covered by substantial layers of sedimentary rocks.
A Comparison of In-Situ Radionuclide Migration Studies in the Studsvik Area and Laboratory Measurements
Authors: LandstrÖm O. , Klockars C.E. , Persson O. , Andersson K. , Torstenfelt B. , Allard B. , Larsson S.Å. , Tullborg E.L.
Published: March 2011

A series of in-situ radionuclide migration tests are in progress in the Studsvik area on the Swedish east coast. Three well defined flowpaths have been located and characterized using non-sorbing tracers (I-131 and H-3), and one of these pathways have been used for a study of the migration of sorbing elements (Sr-85).

Laboratory sorption studies with Sr-85 have been performed on materials (rock-water) from the same location as the field tests and with variation of parameters not easily varied in-situ (e.g. pH and nuclide concentration).

A fairly good correlation was obtained between retention in natural fractures (field experiment) and laboratory column studies, although the latter were performed on crushed samples of whole rock (retention factors 15 – 30).
Radionuclide Retardation and Release Rates for Oceanic Sediments and Clay
Authors: Schreiner F. , Fried S. , Friedman A.
Published: March 2011

The concept of emplacing nuclear waste in the argillaceous sediments covering extensive regions of the ocean floor is being given serious consideration by a group of interested nations.1 For such a subseabed repository to be acceptable the effectiveness in isolating the radioactive material must be demonstrated. Since the waste form cannot be relied upon to retain its integrity in the suboceanic environment, the subseabed repository relies principally on the containment qualities of the sediment that forms the geologic barrier impeding the spread of radionuclides.
Some Aspects of The Influence of Surface and Ground Water Chemistry on The Mobility of Thorium in the “Morro Do Ferro” - Environment.
Authors: Miekeley Norbert , Vale Maria G.R. , Tavares Terezinha M. , Lei Wayne
Published: March 2011

Information concerning the migration of thorium in natural environments is of interest in studies related to impact evaluations of mining and milling operations, to geochemical prospecting and at some point, to predict the long-term behavior of critical waste nuclides.
Studies of the Mobilization of Thoriun from the Norro Do Ferro
Authors: Eiseneud H. , Lei W. , Ballad R. , Penna Franca E. , Niekeley N. , Cullen T. , Krauskopf K.
Published: March 2011

The Morro do Ferro1,2,3 is a hill on the Pocos de Caldas plateau in the state of of Minas Gerais, Brazil which, except for a few monazite beaches, may have the highest levels of natural radioactivity of any place on the surface of the earth (1–3 mK/hr). The radioactivity originates from an ore body located on the upper slopes of the hill (Fig. 1), which rises about 140 m above its surroundings to a maximum altitude of 1540 m. The ore body is estimated to contain about 20,000 metric tons of Th and a somewhat greater quantity of rare earths. The Morro do Ferro has been the site of a number of radiobiological studies conducted during the past 20 years.4,5,6,7
Modelling of the Migration of lanthanoids and Actinoids in Ground Water; The Medium Dependence of Equilibrium Constants.
Authors: Biedermann G. , Bruno J. , Ferri D. , Grenthe I. , Salvatore F. , Spahiu K.
Published: March 2011

Radioactive products may be released from a nuclear waste repository to the biosphere through dissolution in, and transport by ground-water. The fundamental chemical phenomena involved are solubility, complex formation, redox and sorption (e.g. ion-exchange) processes. A first estimate of the behaviour of the waste-repository-ground water system is usually obtained by using a chemical equilibrium model in order to calculate properties such as chemical speciation and solubilities of important radionuclides. For practical reasons the modelling is often made in two different regions, the near field and the far field. In the latter, the main components of the aqueous phase are essentially those of undisturbed groundwater, while in the former substantial changes in composition may occur. The total electrolyte concentration is usually small, at least in the farfield region.
Radionuclide Retardation During Transport Through Fractured Granite
Authors: McKinley Ian G. , West Julia M.
Published: March 2011

In several countries low permeability crystalline rocks (e.g. granites) are under consideration as potential hosts for radioactive waste repositories. In such formations groundwater flow occurs predominantly in specific fractures rather than being a general porous flow through the entire rock matrix. By considering fractures to be simple parallel plates various authors have demonstrated the potential importance of diffusion into dead-end pores and the rock matrix itself (‘matrix diffusion’) as a mechanism for the retention of migrating radionuclides. Complementing these theoretical studies, several insitu migration experiments are planned in single fissures in crysalline rocks in Sweden, the U.K. and the U.S.A. The ‘parallel plate’ approximation to a single fissure is, however, acknowledged to be a gross simplification of any real case where “flowing” fractures are expected to be either filled or coated with secondary minerals, formed by hydrothermal alteration of fracture surfaces In the evaluation of net radio-nuclide retardation, therefore, the effect of sorption onto such secondary minerals must be carefully considered.