bluuebunny/crossref_metadata_2025 huggingface dataset:
High Coefficient of Performance Quantum Well Thermoelectric Nano Cooler
Authors: Jovanovic Velimir , Ghamaty Saeid , Krommenhoek Daniel , Bass John C.
Published: January 2010

Nanotechnology quantum well thermoelectric materials have been developed that have high Figures of Merit and that can attain very high coefficients of performance (COP) to satisfy the requirements for cooling room temperature detectors. Hi-Z Technology, Inc. (Hi-Z) has developed Si/SiGe solid state quantum well (QW) thermoelectric (TE) materials that have demonstrated a Seebeck coefficient and thermoelectric properties that provide >4X higher conversion efficiencies than the current bulk TE materials. With the new Si/SiGe QW materials, cooling systems can be designed that are much smaller, quieter, lighter weight, and that have much reduced power requirements than current TE materials or presently used vapor-compression systems. On-going development for these new QW TE materials has demonstrated high-efficiency TE materials for power generation applications ranging from providing power for wireless sensors to converting waste heat from diesel engine exhaust directly to electricity and thus reducing the load on the alternator and reducing fuel consumption. Now, cooling devices with a high coefficient of performance (COP) are feasible and are being designed for room temperature detector cooling applications. Multi-layer nanocomposite QW films (each 10 nm thick) were fabricated to demonstrate that Si/SiGe QW materials can be deposited on a low thermal conductivity substrate and provide at least the desired COP over the required temperature range of 250K to 350K in a single-stage nano cooler. These QW thermoelectric materials can also be implemented into commercial equipment in the air conditioning and refrigeration applications, thus eliminating fluids, ozone-impacting refrigerants and compressors. Thermoelectric properties of QW thin-film materials have been measured at Hi-Z, several universities and national labs. The conversion efficiency of QW materials has been measured at Hi-Z in two different test couples and in a two-couple device. In all cases, good agreement was obtained between the measurements and prior analytical predictions. Cooling performance was measured in a test with one QW TE element and good agreement was obtained between measurements and analytical predictions. TE properties of the Si/SiGe QW material used in the analysis and design of the subject TE nano cooler were recently independently verified at University of California San Diego (UCSD) and the U.S. National Institute of Standards and Technology (NIST). This paper deals with the analysis of a high COP QW TE single-stage nano cooler for room temperature detectors and with the improved TE properties obtained with the QW thin-film materials resulting in such high COP designs.
Pb-Free Process Development for a High End Storage Area Network Application
Authors: Gopakumar Sunil , Billaut Francois , Fremd Eric , Economou Manthos
Published: January 2010

Lead free solders are being increasingly used in the electronic industry. While most of the electronic products, in terms of volume, are already built lead free, sectors of the industry including high end servers, networking and telecommunications are covered by “lead in solder” exemptions. It is unknown at this point how long these exemptions will last. In addition, many components such as memories have started appearing only in the Pb-free version. As a result, the industry has been pushed to either adopt a mixed assembly process or to transition early to a full Pb-free process. Even though numerous papers have outlined the successful implementation of a Pb-free process, few of them have actually looked at complex high-end multilayer boards in its entirety. This paper focuses on the issues involved in developing an acceptable Pb-free process window for thick, multilayer boards for SMT, Wave soldering, Rework and Press-fit operations. A laminate capable of withstanding Pb-free soldering temperatures was used to construct a 125-mil thick multilayer board with 18 layers which included 8 ground and 10 signal planes. This experiment utilized two popular Pb-free finishes commonly used in the industry: Immersion Silver and high temperature Organic Solderability Preservative (OSP). The widespread SAC 305 alloy with a composition of Sn3.0Ag0.5Cu was used for both SMT and wave soldering. Three sets of assemblies were built: Pb-free, Mixed and Sn/Pb. The mixed assembly mostly used Pb-free components with Sn/Pb solder paste. The impact of increased soldering temperatures on the board, components and reliability of the product were also studied as a part of this research endeavor. Board level reliability tests were conducted by subjecting the boards from 0°C to 100°C Air-to-Air thermal cycling as well as mechanical shock and vibration tests. A suite of reliability and destructive physical analysis (DPA) tests were carried out to establish the quality of the soldering using the eutectic Sn/Pb assembly as the baseline. The study compared the cycling performance of the three sets of assemblies and also looked at the potential impacts of moving to mixed assemblies. Results indicated a reduced process window for Pb-free, especially for the Pb-free wave soldering process due to reduced wetting of the plated through hole barrels as compared to Sn/Pb wave soldering process. The thermal cycling performance of the three sets of assemblies was found to be equivalent after 6000 cycles.
Ergonomic Temperature Limits for Handheld Electronic Devices
Authors: Berhe Mulugeta K.
Published: January 2010

In the drive towards smaller but more powerful electronic systems, effective thermal management issues continue to be among the key challenges facing the electronic industry. With this drive comes increasing heat production that must be removed for a satisfactory and safe operation. In large systems, one of the main challenges is how to achieve acceptable junction temperature of components such as microprocessors. In small systems such as handheld devices, however, one of the main challenges is maintaining the enclosure temperature below certain threshold so that they can be handled and operated without much discomfort. Whether the device is cooled passively or actively, a portion of the total heat generated by components is dissipated through the enclosure. This heat is then dissipated from the skin by radiation and natural convection into the ambient, and by conduction into any body that is in touch with it. So, when a device is held by hand, part of the heat produced will flow into the hand by conduction. The higher the temperature of the enclosure, the greater the heat transfer into the hand will be. Thus, whereas some devices feel cool to the touch, others will feel hot when touched. In order to characterize touch comfort, we must answer some basic questions: What determines whether a device feels hot or not? That is, what are the variables that control touch comfort? Is there a maximum skin temperature limit that we can say is acceptable for touch comfort? In this paper, we shall attempt to answer these and related questions. Among the results we report in this paper include that touch comfort not only depends on the absolute enclosure temperature of the device but also on the thermal conductivity of the enclosure. Materials with high conductivity transfer greater amount of heat into the hand than materials with low conductivity. Thus, a device with aluminum enclosure will feel hotter when touched than a device with plastic enclosure dissipating the same amount of heat. Further, depending on enclosure material type and ambient conditions, one can identify a skin temperature limit beyond which touch comfort deteriorates and becomes unacceptable. For the form factor studied, it was determined that the skin temperature limit for a plastic enclosure was about 45 C, and for aluminum enclosure it was about 41 C.
Leading Prognostic Indicators for Health Management of Electronics Under Thermo-Mechanical Stresses
Authors: Lall Pradeep , Hande Madhura , Bhat Chandan , Suhling Jeff
Published: January 2010

Methodologies for prognostication and health monitoring can significantly impact electronic reliability for applications in which even minimal risk of failure may be unbearable. Presently, health monitoring approaches such as the built-in self-test (BIST) are based on reactive failure diagnostics and unable to determine residual-life or estimate residual-reliability [Allen 2003, Drees 2004, Gao 2002, Rosenthal 1990]. Prognostics health-monitoring (PHM) approach presented in this paper is different from state-of-art diagnostics and resides in the pre-failure-space of the electronic-system, in which no macro-indicators such as cracks or delamination exist. Applications for the presented PHM framework include, consumer applications such as automotive safety systems including front and rear impact protection system, chassis-control systems, x-by-wire systems; and defense applications such as avionics systems, naval electronic warfare systems. The presented PHM methodologies enable the estimation of prior damage in deployed electronics by interrogation of the system state. The presented methodologies will trigger repair or replacement, significantly prior to failure. The approach involves the use of condition monitoring devices which can be interrogated for damage proxies at finite time-intervals. The system’s residual life is computed based on residual-life computation algorithms. Previously, Lall, et. al. [2004, 2005, 2006] have developed several leading indicators of failure. In this paper a mathematical approach has been presented to calculate the prior damage in electronics subjected to cyclic and isothermal thermo-mechanical loads. Electronic components operating in a harsh environment may be subjected to both temperature variations in addition to thermal aging during use-life. Data has been collected for leading indicators of failure for 95.5Sn4Ag0.5Cu first-level interconnects under both single and sequential application of cyclic and isothermal thermo-mechanical loads. Methodology for the determination of prior damage history has been presented using non-linear least-squares method based interrogation techniques. The methodology presented used the Levenberg-Marquardt Algorithm. Test vehicle includes various area-array packaging architectures soldered on Immersion Ag finish, subjected to thermal cycling in the range of −40°C to 125°C and isothermal aging at 125°C.
Optimization of Si/SiGe Microrefrigerators for Hybrid Solid-State/Liquid Cooling
Authors: Ezzahri Y. , Singh R. , Christofferson J. , Bian Z. , Shakouri A.
Published: January 2010

Monolithic Solid-state microrefrigerators have attracted a lot of attention during the last ten years since they have the potential to solve some of the problems related to localized heat generation and temperature stabilization in optoelectronic, microelectronics or even biological microchip applications. Combination of the solid-state cooling with other conventional techniques like liquid cooling, offers an additional degree of freedom to control both the overall temperature of the chip and to remove hot spots. We present a new approach based on Thermal Quadrupoles Method to model the behavior of a single stage Si/SiGe microrefrigerator in the DC operating regime. The sensitivity and precision of this method come from its analytical expressions, which are based on the solution of Fourier’s heat diffusion equation in the Laplace domain. The microrefrigerator top surface temperature is calculated by taking into account all possible mechanisms of heat generation and conduction within the entire device. The 3D heat and current spreading in the substrate is taken into account. The parasitic heat leakage to the cold junction due to heat generation and heat conduction within the metal lead is also considered. The theoretical results are then compared with experimental ones for several microrefrigerator sizes. A good agreement is found between them. Based on the simulations, the structure of the microrefrigerator is optimized for lowering the overall chip temperature and removing high power density hot spots in several applications in conjunction with liquid cooling techniques.
A Novel Airflow Management System With Redundant Fan Field Replaceable Units
Authors: Shabany Younes
Published: January 2010

A novel airflow architecture for a networking chassis will be described in this work. This chassis is a pull system with two sets of four fans located in series at its exhaust. Each set of four fans is a field replaceable unit (FRU). The unique feature of this chassis is that one set of fans, called the rear fan FRU, is replaceable from the rear side of the chassis and the other set of fans, called the front fan FRU, is replaceable from the front side of the chassis. Computational fluid dynamics simulations and measurement data show this chassis is capable of providing up to 78% – 79% of its maximum cooling capacity when one fan FRU is removed from the chassis, and up to 62% – 67% of its maximum cooling capacity when one fan FRU has failed.
A Stamp-Sealed Microshell Package for RF MEMS Switches
Authors: Heck John , Bar Hanan , Chou Tsung-Kuan A. , Tran Quan , Ma Qing , Weinfeld Boaz , Rao Valluri
Published: January 2010

This paper describes a unique method of encapsulating MEMS switches at the wafer level using a thin-film “microshell” lid and a novel micro-embossing, or “stamping” technique to seal the lid. After fabrication of the MEMS switch and subsequent formation of the microshell, the switches are released through gold tunnels that allow the penetration of a chemical etchant. In a controlled ambient, a “stamp” wafer is aligned to the device wafer, and the wafers are thermally compressed together. This process applies pressure across each tunnel to fuse the gold, thereby sealing the microshell packages. By sealing and passivating the switches at the wafer level, the wafers can be exposed to backend processing, packaging, and assembly steps such as dicing without damaging the sensitive MEMS devices. Furthermore, the size, cost, and complexity of the packaged system are significantly reduced compared to standard wafer bonding processes.
Fan Laws for Rack Systems
Authors: Holahan Maurice F. , Elison Bret P.
Published: January 2010

As datacenter aisle noise levels approach OSHA workplace limits, air-cooled server racks share with desktop workstations the ultimate problem of being thermally constrained within a finite packaging volume by acoustic emission restrictions. The primary source of noise in most scalable 1 and 2 EIA rack drawers is an air moving device. Multiple compact dual stage counter-rotating bladed tubeaxial devices are being adopted to overcome the pressure drop of increasingly densely packed electronics. The design problem of maximizing hydraulic output within space and noise constraints naturally leads to the question of whether these many smaller fans could be gainfully replaced by fewer but larger fans. To examine this question, the fan laws for single devices are extended to equivalent systems of multiple parallel and series fans. The principle of impedance matching is applied to hydraulic sources and loads to maximize pumping power. A novel method is introduced to map fan speed, size, and hydraulic performance. The paper provides a proof that equal-staged noise-neutral space-filling planar arrays of parallel homologous devices must deliver the same net rack flow and pressure, and it shows that series arrangements of multiple stages of planar parallel fan arrays will always, under acoustic parity conditions, yield increased pressure at diminishing flow with each successive stage. At equivalent system hydraulic output, larger fans in series are shown to consume greater packaging volume while achieving lower overall acoustic output. Net rack flow and pressure relationships are also quantified for systems of equal total rack fan shaft power input. Examination of actual unit level fan noise measurements suggests that in practice, systems of small fans typically output 4 to 9 dB higher noise levels than larger fans operated at the same net flow and pressure. Finally, a survey of unit level airflow and power input measurements reveals that larger fans exhibit higher total efficiency than smaller fans.
Finite Element Analysis of Laser Fabricated Microjoint Performance in Cerebrospinal Fluid
Authors: Mian Ahsan , Law Jesse
Published: January 2010

Assessment of neural biocompatibility requires that materials be tested with exposure in neural fluids. Laser bonded microjoint samples made from titanium foil and polyimide film (TiPI) were evaluated for mechanical performance before and after exposure in artificial cerebrospinal fluid (CSF) for two, four and twelve weeks at 37°C. These samples represent a critical feature i.e., the microjoint — a major weakness in the bioencapsulation system. The laser microbonds showed initial degradation up to four weeks which then stabilized afterwards and retained similar strength until twelve weeks. To understand this bond degradation mechanism better, a finite element modeling approach was adopted. From the finite element results, it was revealed that the bond degradation was not owing to the hygroscopic expansion of polyimide. Rather, relaxation of the process induced residual stresses may have resulted in weakening of the bond strength as observed from experimental measurements.
Effects of Tooling Tip Wear and Fixture Rigidity on Solder Ball Shear and Ball Pull Tests
Authors: Song Fubin , Lee S. W. Ricky
Published: January 2010

The present study is aimed at evaluating the effect of ball shear tool wear and fixture rigidity on ball shear and ball pull tests respectively. In particular, the emphasis is placed on understanding the progressive failure mechanism during the ball shear test. The location of crack initiating is investigated on two kinds of shear tool with different wear features. In this paper, the experimental investigation is presented. Specimens with PBGA solder balls are fabricated and a series of ball shear and pull tests are conducted. In the shear test, the shear tool is stopped at a certain stage during test, and then the specimens are inspected by SEM. The failure modes and location of cracks are characterized. From the ball attachment strength and crack location of the ball shear test, no significant difference is found between the shear tools with different wear features. For investigating the effect of fixture rigidity on the ball pull test, two kinds of PBGA package with different sizes was fixed on the fixtures with and without gluing on a rigid plate. The failure modes and ball pull strength with different fixture rigidity were compared. The test results indicate that more brittle failures are found on the specimens without gluing on the rigid plate during the ball pull test, both on two kinds of package with different sizes. In addition, the data scattering of ball pull strength is large on the case without gluing on rigid plate.
Robust Underfill Selection Methodology for Flip Chip
Authors: Islam Nokibul , Jimarez Miguel , Darveaux Robert , Lee JoonYeob , Na JaeYoung , Kim KeunSoo
Published: January 2010

Underfill is one of the crucial materials in flip chip (FC) packages. The role of underfill is not only to protect the solder bumps but to minimize package warpage, and to protect the fragile low k dielectric at end of line (EOL), moisture resistance test (MRT), and temperature cycle B (TCB) conditions. As packages move towards green products, the complexity of selecting a good underfill increases. The interaction of high Pb or eutectic solder with the underfill is different than that of Pb free solder. Moreover Pb free solder behavior for FC bumps is just being explored in the literature. Besides Pb free solder, other parameters like die passivation, bump height and pitch, under bump metallurgy (UBM) metallization, and package substrate are also extremely important for underfill selection. As the design of the package continues to change smaller package, tighter bump pitch and thinner core and build up (BU) layers, all of these parameters are directly related to package reliability. Sometimes an underfill good for a smaller die, body size, taller bump height, and pitch doesn’t necessarily mean it will be appropriate for a bigger die with larger body, and tighter bumps. So there are lots of variables in the package that directly affect the reliability. A good underfill should have very good adhesion between underfill and die passivation at room temperature, and moderate adhesion at underfill Tg. Adhesion properties are solely depend on chemistry of the underfill. Therefore to determine a good underfill for a bigger die and body size, we need to have a sequential selection methodology. In this paper a sequential selection methodology is used to eliminate the unsuccessful underfill candidates and select the best one which comfortably satisfies the requirements for all different solder alloys, and a wider range of package geometries. Important selection criteria including underfill workability issues and modeling data are also discussed.
An Approach to Determining Residual Strains and Moisture Diffusion Coefficients of Cured Adhesives in Electronic Packaging
Authors: Tsai M. Y. , Huang C. Y. , Chiang C. Y. , Wu C. Y. , Yang S. S.
Published: January 2010

Polymeric adhesives are popular in the application to electronic or optoelectronic packaging for die attaching, underfilling or interconnection. Their residual strains or stresses (induced by temperature, moisture, and curing shrinkage) and moisture diffusion coefficients have to be determined and cooperated into the package design for better reliability. The purpose of this study is to propose an approach for quantifying adhesive moisture diffusion coefficients and residual strains due to chemical shrinkage, stress relaxation and temperature- and moisture-loading. This approach feature testing fully-cured adhesive/silicon bi-material plates under thermal and moisture loading using Twyman-Green (T/G) interferometry system plus analyses with Timoshenko’s bi-material theory and finite element method (FEM). Three types of adhesives: paste adhesive, film adhesives A and B have been tested for illustrating the approach. The results suggest that the residual strains for the paste adhesive are only induced by CTE mismatch during thermal loading, rather than other factors, after the cured paste adhesive being cooled down to room temperature. On the other hand, the film adhesive A was found to have the additional residual strain caused by chemical shrinkage plus stress relaxation, besides thermal one, is about 2.26×10−3, which accounts for 85% of thermal strains, after the bi-material plate being cooled down to room temperature. Through moisture diffusion test, the average of the coefficients of moisture diffusion and saturated hygro-strains of the film adhesive B under 30°C/85%RH are obtained to be 1.09 × 10−6 mm2/s and 1.51 × 10−3, respectively. From the aforementioned results, it has been demonstrated that this method with a combination of experimental data and analytical tools can be able to determine the residual strains and moisture diffusion coefficients of the cured film or paste adhesives.
Optimization of Pin-Fin Heat Sinks in Bypass Flow Using Entropy Generation Minimization Method
Authors: Khan Waqar A. , Yovanovich Michael M.
Published: January 2010

An entropy generation minimization, EGM, method is applied to study the thermodynamic losses caused by heat transfer and pressure drop for the fluid in a cylindrical pin-fin heat sink and bypass flow regions. A general expression for the entropy generation rate is obtained by considering control volumes around heat sink and bypass regions. The conservation equations for mass and energy with the entropy balance are applied in both regions. Inside the heat sink, analytical/empirical correlations are used for heat transfer coefficients and friction factors, where the reference velocity used in Reynolds number and pressure drop is based on the minimum free area available for the fluid flow. In bypass regions theoretical models, based on laws of conservation of mass, momentum and energy, are used to predict flow velocity and pressure drop. Both in-line and staggered arrangements are studied and their relative performance is compared for the same thermal and hydraulic conditions. A parametric study is also performed to show the effects of bypass on the overall performance of heat sinks.
Mechanical Properties of Lead Free Solder Alloy Measured by Nanoindentation
Authors: Sun Y. , Xu Z. H. , Li X. , Shangguan D. , Liang J.
Published: January 2010

The elimination of lead from electronics due to its detrimental effects to environment is pushing component manufacturers to consider lead free solder alloy as an option. Application of lead free solder alloy requires a better understanding of its mechanical behavior at elevated temperatures and at small volume size. Such information is still lacking. In this study, nanoindentation technique was used to investigate the deformation behavior of the near eutectic ternary SAC387 (Sn 95.5 wt%, Ag 3.8 wt% and Cu 0.7 wt%) lead free solder alloy. The mechanical properties of each constituent phase in SAC387 were carefully measured and analyzed. Indentation tests were performed with different holding times to study the creep effects on the mechanical properties measured by nanoindentation. Microhardness tests were also carried out at temperatures above ambient temperature to investigate its influence on the mechanical properties.
On three models of magneto-hydrodynamic free-convection flow
Authors: Ezzat Magdy A. , El-Bary A. A.
Published: January 2010

In this work, we introduce a model of the boundary-layer equations of a generalized thermofluid for an electrically conducting pourous medium in the presence of a constant magnetic field. This model is applied to each generalization, Cattaneo theory with one relaxation time, Chandrasekharaiah–Tzou theory, as well as classical Fourier law. The state space approach developed by Ezzat (Can. J. Phys. 86, 1241 (2008)), is adopted for the one-dimensional problems including heat sources. The resulting formulation is applied to a problem for the whole space with a plane distribution of heat sources. The reflection method together with the solution obtained for the whole space is applied to a semi-space problem with a plane distribution of heat sources located inside the fluid. Numerical results for the velocity, temperature, and induced-magnetic and electric field distributions are given and illustrated graphically for both problems. The comparisons are made for all functions with the results obtained in the three theories.
Influence of collision energy on the axial polarization of product molecule for reaction F + HO → HF + O
Authors: Zhao Juan , Xu Yan , Meng Qing-Tian
Published: January 2010

Quasi-classical trajectory (QCT) calculations are performed for the reaction F + HO(0,0) → HF + O based on the adiabatic potential-energy surface (PES) of the 13 A′′ triplet state. The product molecule axial alignment factor  as a function of collision energy, the distribution P(α) of the angle between k and A, the distribution P(β) of the dihedral angle denoting k – k′ – A correlation, and the angular distribution P(α, β) of the product rotational vectors in the form of polar plots have been calculated in the center-of-mass (CM) frame, respectively. The effects of collision energy and PES on the polarization of the product molecule HF axis vectors A are revealed, which provides the theoretical foundation for the relative experiment.
Revised analysis of singly ionized tellurium: Te II
Authors: Tauheed A. , Joshi Y. N. , Steinitz M.
Published: January 2010

Tellurium spectra were recorded on a 3 m normal incidence vacuum spectrograph in the spectroscopy laboratory of St. Francis Xavier University using a triggered spark light source. The spectrum of the singly ionized tellurium atom was investigated in the wavelength region 746–1838 Å using Hartree–Fock configuration interaction calculations involving 5s25p3, 5s5p4, 5s25p2 (5d + 6d + 7d + 8d + 6s + 7s + 8s + 9s) configurations. Earlier analysis by Handrup and Mack has been revised, and 27 new energy levels have been added, to complete the 5s25p3, 5s25p2 (5d + 6d + 6s + 7s) configurations. Now five levels of the ground-state configuration and 78 of the excited configurations are known. Two hundred and nineteen spectral lines have been classified in this spectrum. Least squares fitted parametric calculations were used for the final interpretation and LS percentage compositions. The wavelength accuracy of our measurement for unblended and sharp lines is ±0.005 Å.
Multiple-soliton solutions for coupled KdV and coupled KP systems
Authors: Wazwaz Abdul-Majid
Published: January 2010

In this work we study two systems of coupled KdV and coupled KP equations. The Hirota bilinear method is applied to show that these two systems are completely integrable. Multiple-soliton solutions and multiple singular-soliton solutions are derived for each system. The resonance phenomenon is examined as well.
STRATEGIC ENVIRONMENTAL ASSESSMENT IN CHINA: OPPORTUNITIES, ISSUES AND CHALLENGES
Authors: LAM KIN-CHE , CHEN YONGQIN DAVID , WU JING
Published: January 2010

Based on literature reviews, case studies and other information available on the web, this paper examines the evolution and status of strategic environmental assessment in China by reviewing the progress that has been made; discussing the issues and problems encountered and exploring the best way forward. It is suggested that the Chinese EIA system has evolved over the years to cope with the rapidity and scale of development in China and the current emphasis on Plan EIA is probably the most appropriate form of SEA given the political reality and complicated institution setup. Given China's environmental and resource problems, the paper affirms the potential role of SEA in fostering a sustainable and harmonious society and the need to mainstream sustainability considerations in the formulation of national plans and strategies. To circumvent political resistance from line agencies, the paper suggests that SEA can be applied, in various names and forms, to national and provincial socio-economic plans.
A peat slide at Glenfiddich, East Grampian Highlands
Authors: Nichol D.
Published: January 2010

Synopsis

A natural peat slide event at Glenfiddich, NE Scotland in August 2004 occurred during a period of rainstorm activity. The mass movement entailed some 700 m
3
of peat debris that obstructed a path, intersected a stream, caused the collapse of a bridge and encroached upon a designated Special Area of Conservation. Four principal factors contributed to the event; (1) prolonged wet weather and heavy rainfall, (2) a steeply dipping rockhead surface of weathered Dalradian psammite, (3) a sheltered north-facing slope and (4) a natural drainage pipe at the point of initiation of the slide. Remedial measures include erosion mitigation by placement of armourstone on parts of the rupture surface and replacement of a bridge across the stream with a ford. A programme of geological surveillance was implemented to monitor any variations in site conditions and identify any additional opportunities for environmental engineering works.
Multi-episodic modification of high-grade terrane near Scourie and its significance in elucidating the history of the Lewisian Complex
Authors: Barooah B. C. , Bowes D. R.
Published: January 2010

Synopsis

The first detailed geological map made of the area south and east of Scourie since that of the pioneer mapping in the NW Highlands of Scotland by the Geological Survey in the latter part of the 19th century is used as a basis for establishing structural, metamorphic and igneous successions in orogenic belts whose ages have been determined from U–Pb isotopic data. The main metamorphic modification of the widespread ≥ 2710 Ma pyroxene granulites formed during an early phase in the development of the Scourian orogenic belt took place at 2490–2480 Ma in an early stage of the development of the Inverian orogenic belt. The predominant expressions of the latter orogen are generally NW-trending single and coalescing fold belts of hornblende – feldspar gneiss. These, and the intervening areas of granulites where there is patchy replacement of pyroxene by amphibole, are cut by a suite of
c
. 2450 Ma dolerite dykes emplaced into crust that was still relatively hot. There is no recorded expression of the
c
. 1.9–1.85 Ga Laxfordian orogenic belt in the domain around Scourie: it was not juxtaposed with the gneiss – amphibolite – granite domain around Loch Laxford until a collision of crustal segments
c
. 1750 Ma ago. The elongate, generally west-trending, mainly complex synformal fold – schist belts (‘pre-Torridonian lines of movement’) that cut across and modify the structural, metamorphic and igneous features of both the Scourian and Inverian orogenic belts are linked to bulk inhomogeneous shortening during the tectonothermal activity associated with this collision and are interpreted as tectonic ‘wrinkles’ on an overriding plate. These events were followed by sinistral transcurrent movements associated with the development of ductile shears and by limited dolerite dyke emplacement. Other weakly expressed metamorphic and structural features are linked to the 1690–1670 Ma mineral ages of a later episode.

An interpretation of the Palaeoproterozoic histories of the domains around Scourie and Loch Laxford as being distinct depends upon the determination of consistent structural, metamorphic and igneous successions. These are based on evidence of the refolding, cross-cutting and overprinting relationships within the two domains, and on the integration of isotopic data into these successions. The availability of corresponding information in other parts of the Lewisian Complex is essential in order to establish the presence of other terranes in the Complex and to determine their areal extent.
Primary magmas and the origin of basalts
Authors: O’Hara M. J.
Published: January 2010

Synopsis

Basaltic rocks have chemical compositions and behave under experimental conditions in a way which suggests that extrusive basalt magmas are, in the main, the residual liquids of well advanced crystal fractionation processes operating at relatively low pressures. Once this is admitted, there is no reason to deny that such magmas have undergone appreciable crystal fractionation at all depths during their movement to the surface. The compositions of extrusive basalts should, therefore, be regarded as the end products of a continuous series of evolutionary changes whose precise effects will depend upon the place where partial melting occurred, and the rate at which the liquids move towards the surface relative to the rate of cooling. An attempt is made to construct a petrogenetic scheme for the basic magmas based on this view of igneous activity.
A marine magnetic survey near Lerwick, Shetland Isles
Authors: Wilson C. D. V.
Published: January 2010

Synopsis

A total force magnetic survey has been made of an offshore area (14 km × 12 km) near Lerwick, Shetland Isles, where the Admiralty Chart shows an anomaly in the magnetic variation. The survey shows a strong positive anomaly, suggestive of a basic rock magnetised in a direction close to that of the present Earth’s field.

A block model has been fitted to the total force field, and the computed anomaly in magnetic variation agrees with that shown on the chart. Steep magnetic gradients and irregular sea-floor topography suggest that the body may outcrop on the sea floor and could be sampled by dredging.

The nature of the body is discussed; it is thought that it may be a pre-Middle Devonian intrusion.
Websterite from Glenelg, Inverness-shire
Authors: Mercy E. L. P. , O’Hara M. J.
Published: January 2010

Synopsis

Chemical analyses and optical data are given for the coexisting pyroxenes of a websterite specimen from Glenelg. The mineral assemblage is believed to represent equilibration at high pressures and low temperatures. The rock is thought to be associated with the eclogites of the Glenelg province.
The West Glasgow Earthquake—7 March 1964
Authors: Bowes D. R.
Published: January 2010

Synopsis

On the basis of surface observations, the epicentre of the West Glasgow Earthquake, which occurred at 7.03 a.m. on 7 March 1964, is located in the Blairdardie district at approximately W. Long 4°21′.2, N. Lat 55°54′.1. It is suggested that the focus was on the western margin of the Paisley Ruck at the boundary of the Old Red Sandstone and Calciferous Sandstone Series (depth 1·6 km).
Successive periods of basic dyke emplacement in the Lewisian complex, south of Scourie, Sutherland
Authors: Bowes D. R. , Khoury S. G.
Published: January 2010

Synopsis

Basic dykes showing cross-cutting relations to one another, and different tectonic and metamorphic histories, but having similar chemical composition, are interpreted as having been emplaced during the Inverian and Laxfordian orogenies respectively.
A structural study of the granitic gneiss of Western Ardgour, Argyll and Inverness-shire
Authors: Dalziel Ian W. D.
Published: January 2010

Synopsis

The paper describes a structural study of part of the discontinuous belt of granitic gneiss extending from Glen Tarbert (Argyll) to north of Loch Quoich (Inverness-shire). The granitic gneiss outcrops immediately west of the boundary between the ‘highly inclined’ and ‘flat’ belts of the Moines (the Loch Quoich line) which is the eastern limit of outcrop of the regional migmatite belt (‘injection belt’).

The Loch Eil psammitic belt (which constitutes the ‘flat’ belt) is the highest structural and stratigraphical unit of the area, overlying a thin pelitic horizon which rests on striped schists. Contrary to earlier correlations it is thought that all these units may overlie the classical Morar succession.

Four main fold episodes (F1–F4) are recognisable. The granitic gneiss is entirely concordant, lies at the same horizon as the striped schists, and probably occupies the core of a tight F2 fold of highly variable plunge. Formation of the gneiss began prior to the second fold movement and it behaved during deformation as did the adjacent metasediments.

The structural history of the gneiss is consistent with a migmatitic origin, and it was concentrated in a narrow belt by tectonic control.
The structure of the Queen’s Cairn Rhyolite, Glen Coe, Argyllshire
Authors: Ferguson David K.
Published: January 2010

Synopsis

A banded rhyolite in Glen Coe has been investigated structurally. This analysis reveals that the present attitude of the fold-axes and flow-planes is largely, if not entirely, the result of reorientation which followed extrusion.
The Thermal Aureole of the Haddo House Norite in Aberdeenshire
Authors: Gribble C. D.
Published: January 2010

Synopsis

The Ythan valley demonstrates the extent of the aureole of the Haddo House norite in the Fyvie schists. In the pelites the replacement of the regional cordierite, one and a half miles from, the norite, by muscovite and quartz implies a potash metasomatism but this cannot be proved from the chemical data. Although outcrop is poor, there is little doubt that temperatures high enough to mobilise the country rocks were operative very near the basic mass.
Zoned ultrabasic bodies in the Lewisian of the Moine Nappe in Skye
Authors: Matthews D. W.
Published: January 2010

Synopsis

A number of new examples of zoned associations of talc, actinolite, chlorite, and biotite appear to have been derived by reaction during regional metamorphism of moderate intensity between small ultrabasic masses and more acid country rock. The formation of the most abundant type of zone was governed by diffusion of Mg. Although the zone-forming processes have not proceeded to equilibrium, there are some indications of a degree of attainment of local equilibrium.
Intrusive coal at Douglas in Scotland
Authors: Lumsden G. I.
Published: January 2010

Synopsis

In the outlier of Carboniferous sediments around Douglas a recent borehole proved dolerite intrusions for the first time in the upper part of the Limestone Coal Group of Namurian age. The dolerite has been intruded into the Robb and Back coals and the overlying marine mudstones of the Black Metals. It has subsequently been altered to white trap in part, by reaction with organic gases distilled from the carbonaceous sediments. Burnt coal associated with white trap was found in the borehole as sill-like bodies at three horizons amongst the marine Black Metals and also infilling steeply inclined joints higher in the sequence between the Kirkroad and Big Drum coals. No coal has been recorded at these horizons in numerous boreholes and extensive mining elsewhere in the outlier. The aberrant coals are considered to be intrusive and originally part of the Back Coal. The intrusion took place when the coal was heated by the dolerite to a critical temperature at which it became plastic. The known extent of the intrusion of coal is to a level 140 ft above the seam of origin.
The metamorphic evolution of the Moine Nappe in Skye
Authors: Matthews D. W. , Cheeney R. F.
Published: January 2010

Synopsis

The metamorphic history of these Moine and Lewisian rocks in the Moine nappe of Skye is as complicated as the structural history, one of the principal difficulties being the recognition of equilibrium assemblages. Detailed work on an important garnet-hornblende-biotite-epidote assemblage in gneissic rocks indicates that the highest metamorphism was probably of lower almandine amphibolite fades and that it occurred early in the structural history of the area.

Later retrograde changes took place in schistose rocks nearer the Moine thrust plane. Co-existing chlorite-actinolite assemblages, analysed in detail, indicate a metamorphic grade probably not much lower than the almandine amphibolite facies.
Fossil beetles collected by James Bennie from Late Glacial silts at Corstorphine, Edinburgh
Authors: Coope G. R.
Published: January 2010

Synopsis

Remains of Coleoptera, collected by James Bennie at the end of the last century from Late Glacial deposits in Edinburgh, are described. All the fragments recognised can be identified with living species, but five of them are not now found living in Britain. The fauna is indicative of a marshy environment rather than a lake as had hitherto been assumed. For the most part the fauna indicates sub-arctic conditions with a somewhat more continental climate than prevails in Edinburgh at the moment. There are however certain anomalous associations in this assemblage which may be reconciled to some extent by assuming that the climatic regime of Late Glacial Edinburgh has no precise equivalent anywhere in Europe today. An attempt is made to put together a picture of a climatic regime that might have been acceptable to all the species in this fauna.
The ages of some kentallenite intrusions in Argyll
Authors: Westoll N. D. S. , Miller J. A.
Published: January 2010

Synopsis

Potassium-argon biotite age determinations of three masses of kentallenite in Argyll range from 391±12 m.y. to 405±12 m.y. These ages are used in conjunction with field evidence to suggest a revised time sequence for the Caledonian igneous activity in the Southwest Highlands of Scotland.
Rare flange-bearing productacean brachiopods from the Carboniferous of the British Isles
Authors: Shiells K. A. G.
Published: January 2010

Synopsis

Kochiproductus
, a buxtoniid productacean brachiopod, is redefined and restricted to five species:
K. porrectus
Kutorga,
K. peruvianus
d’Orbigny,
K. plexicostatus
Dunbar,
K. coronus
Shiells, and
K. magnus
sp. nov. This genus, previously only recognised at a single exposure in the British Isles, is here recorded from 22 other localities. Ninety-one specimens of
K. coronus
and
K. magnus
sp. nov., are now known from the British Isles. Since this material is so rare, a generic identification indexing scheme is introduced to indicate which generic attributes each specimen exhibits. The index letters used can be assigned a relative taxonomic importance, and thus indicate the probability of correctness of individual determinations. Four specimens of
Pustula labrifera
sp. nov., a flange-bearing echinoconchid productacean, are also described.
Some stone-orientation results from the Forth Valley
Authors: Burke M. J.
Published: January 2010

Synopsis

This paper is based on 40 till fabric analyses undertaken in the Forth Valley, an ice-moulded lowland.

Only 31 of the sites had significant (anisotropic) orientations as obtained by vector analysis. Of these, 17 were parallel to the presumed local direction of ice-movement—generally west to east, except for the Midlothian Basin, where it was south-west to north-east. Of the remainder, 1 was transverse to ice-movement; 8 were oriented in the direction of slope of the ground; and 5 appeared unrelated either to ice-movement or slope. The deflecting influence of numerous crags and hills may help to explain the absence of definite orientations at some sites.

Orientation evidence, together with pH and particle-size analysis, has also revealed a clear distinction between ‘boulder clay’ and the superficial ‘sandy clay with stones’. The boulder clay was a compact, less-leached deposit, with a better organisation of stones, producing fabric diagrams that usually had a preferred orientation parallel to the local ice-movement. The results suggest that most of the sandy clay with stones was produced by washing of the upper parts of the boulder clay during immediate post-glacial times.
On the development of coastal profiles in the north of Scotland, Orkney and Shetland
Authors: Flinn Derek
Published: January 2010

Synopsis

The sea cliffs of the north of Scotland, Orkney and Shetland continue to a considerable depth beneath the sea before they meet the flat sea floor. The depth at which this junction occurs increases steadily northwards from about 30 fathoms in north-east Scotland to about 45 fathoms in Shetland. The profile of the coast from the final break of slope to the waterline is usually concave upwards, but in many places it is formed of a series of steps. It is argued that this coastal profile is due to marine erosion acting over a long period of time at a series of different levels due to changes in the height of the sea relative to the land.
A re-assessment of the ‘younger’ basic igneous rocks between Huntly and Portsoy based on new borehole evidence
Authors: Munro M.
Published: January 2010

Synopsis

Sixty-five holes drilled between Huntly and Portsoy have shown that undeformed, basic igneous rocks in this region occupy a smaller area than is shown on existing maps and that the single intrusion previously recognised—the ‘Huntly mass’—does not exist. Three smaller bodies of basic rock, which appear to consist largely of cumulates and xenolithic rocks, can be identified. The structures in the cumulates appear to be nearly vertical in most instances, but no clear evidence of folding has been found in these rocks, although certain of the igneous boundaries appear to have been intensely deformed. Xenoliths are highly metamorphosed, but otherwise there is little evidence of thermal metamorphism in the vicinity of the basic rocks, even when the latter consist of cumulates.
Geophysical studies of the basic intrusions
Authors: Wilson C. D. V.
Published: January 2010

Synopsis

Re-examination of the gravity and magnetic anomalies over the Maud intrusion shows that it is magnetised in a direction close to that of Blundell and Read’s (1958) specimens. A magnetic survey of some dykes near Straloch suggests that they may be associated with the basic sheet.

Seismic velocities for the Macduff Slates have been obtained at two sites near the Insch mass; at one of these there is a high-velocity layer which may be gabbro.

Some of the anomalies found in the recent aeromagnetic survey by the Institute of Geological Sciences are discussed and provisional interpretations suggested.

Possible modes of emplacement of the basic sheet are discussed and the role of geophysics in the study of the sheet is reviewed.