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The II–VI compound semiconductor CdSe, which has both zincblende (ZB) and wurtzite (WZ) phases with bandgap energies of 1.67 and 1.74 eV, respectively, is an ideal candidate material for the top cell in a tandem solar cell with a Si bottom cell to achieve higher power conversion efficiency. In this work, molecular beam epitaxy growth of CdSe thin films on lattice-matched InAs(100) substrates reveals a single-phase ZB structure with high crystallinity and a low defect density. In contrast, all CdSe layers grown on InAs(111)B substrates have mixed ZB and WZ phases in coexistence, as confirmed by high-resolution X-ray diffraction, transmission electron microscopy (TEM), and photoluminescence (PL) measurements. The PL efficiencies of the CdSe layers grown on (111)B substrates are substantially lower than those grown on (100) substrates. This result is attributed to defects at the boundaries between the two different phases. Postgrowth annealing of CdSe layers grown on InAs(111)B at 250–450 °C converts most of the CdSe ZB material into the WZ phase, as evidenced by improved PL efficiency and TEM images. Density functional theory simulations confirm that the formation energy difference between the ZB and WZ phases for CdSe is very small compared with other conventional compound semiconductors, which is in good agreement with the experimental observations.

The ability to directly image charge accumulation in the irradiated oxide film of the metal–oxide-semiconductor capacitor (MOSCAP) is demonstrated using the electron holography technique. Capacitors with 100 nm thickness of oxide film are fabricated and irradiated using a 60Co gamma source to a target total dose of 450 krad(SiO2). Electric and materials analyses are performed before and after irradiation to study the total ionizing dose (TID) effect. The observed leftward shift in the capacitance–voltage ( ${C}$ – ${V}$ ) curve and a larger potential drop near the Si/SiO2 interface mapped by electron holography indicate charge buildup at the irradiated oxide layer. Technology computer-aided design (TCAD) simulations are performed to analyze and validate the electrostatic potential data from holography and also quantify the charge distributions across the oxide layer for both preirradiated and postirradiated devices. A larger amount of positive volumetric charges is added near the oxide/silicon interface for the irradiated sample in order to fit both ${C}$ – ${V}$ measurement data and electron holography profiles. The good matching between the experimental and simulation results shows evidence that electron holography provides the ability to directly image the charge accumulation at the irradiated oxide layer due to TID effects.

ABSTRACTThis research presents a mix design methodology for geopolymer (GP) and alkali activated (AA) mortars based on metakaolin and industrial waste products activated using potassium silicate. The aim is to enable a wide range of mix designs to be specified to given compressive strength, consistency and environmental footprints to facilitate their adoption as a Portland cement (PC) alternatives in the construction industry in applications such as fibre-reinforced building cladding systems. The impact of the work is timely as literature quantifying the effects of mix parameters on broad families of GP and AA materials are limited, and no standardized performance-based methodology exists. Initially, effects of binder composition on mechanical and environmental properties are presented for a standard GP mix design using contoured ternary plots for a range of material blends. Next, effects of altering mixture parameters such as liquid/solid, silica/alumina and activator/binder ratios are quantified for three selected binder compositions before a preliminary mix design methodology is presented allowing initial selection of mixture proportions. Finally, correlation analysis is used to identify multiple mix variables strongly correlating with strength, and regression modeling used to present predictive tools with average errors <6%.

There is a direct relationship between bodyweight and risk of diabetes. Lorcaserin, a selective serotonin 2C receptor agonist that suppresses appetite, has been shown to facilitate sustained weight loss in obese or overweight patients. We aimed to evaluate the long-term effects of lorcaserin on diabetes prevention and remission.

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The Antarctic Slope Current (ASC), defined here as the region of westward flow along the continental slope off Antarctica, forms the southern limb of the subpolar gyres. It regulates the exchange of water across the shelf break and provides a path for interbasin westward transport. Despite its significance, the ASC remains largely unobserved around most of the Antarctic continent. Here we present direct velocity observations from a 17 month current meter moored array deployed across the continental slope between the 1000 and the 4200 m isobaths, in the southeastern Indian Ocean near 113°E. The observed time‐mean flow consists of a surface‐intensified jet associated with the Antarctic Slope Front (ASF) and a broader bottom‐intensified westward flow that extends out to approximately the 4000 m isobath and is strongest along the upper slope. The time‐mean transport of the ASC is −29.2 Sv. Fluctuations in the transport are large, typically exceeding the mean by a factor of 2. They are mainly due to changes in the northward extent of the current over the lower slope. However, seasonal changes in the wind also drive variations in the transport of the ASF and the flow in the upper slope. Both mean and variability are largely barotropic, thus invisible to traditional geostrophic methods. The mean transport of the Antarctic Slope Current (ASC) is −29.2 SvMean and variability of the ASC are predominantly barotropicVariability is due to open ocean eddy processes and wind forcing through changes in the Antarctic Slope Front

The Usangu wetlands, containing the Ihefu swamp, are one of the most valuable inland wetlands in Tanzania. Over the last decade, outflow from the swamp has ceased for extended periods in the dry season. This has had severe consequences for downstream ecosystems, including the Ruaha National Park. Results from a simple hydrological model developed for the Ihefu swamp indicate that, between 1958 and 2004, dry season inflows declined by approximately 60% and the dry season area of the swamp decreased by approximately 40% (i.e. from 160 km2 to 93 km2). The model also shows that to maintain minimum downstream environmental flows requires a minimum inflow of 7 m3s-1, which is approximately 65% greater than occurs currently. There is significant potential for improving water use efficiency. However, given the socio-economic importance of current levels of water withdrawal, this inflow may be difficult to achieve. Consequently consideration needs to be given to other options, including upstream storage and water management within the wetland itself. This paper highlights that a simple model supplying relatively low-confidence, but indicative, results can provide a useful basis for contemplating water management options.

This paper suggests that the relative salt (sodium chloride) dilution method should be more widely used for the routine measurement of stream discharge, and has been written to increase awareness of the technique among flow‐gauging practitioners. Recent improvements in instrumentation have increased accuracy and simplified practical application, making the method better suited (in many circumstances) than the more widely used alternatives. The paper (a) reports on a field study to evaluate the performance of a portable dilution‐gauging flowmeter, and (b) considers the environmental issues which are associated with the method. The review reveals that the use of salt (in the quantities typically required) is unlikely to have any significant ecological impact, and argues that environmental concerns are founded upon little scientific basis.

Background In independent linkage studies chromosome 2q11‐q24 and chromosome 2q23–35 have previously been implicated as regions potentially harbouring susceptibility loci for osteoarthritis (OA).Objective. To test chromosome 2q for linkage to idiopathic osteoarthritis.Methods. Using a cohort of 481 OA families that each contained at least one affected sibling pair with severe end‐stage disease (ascertained by hip or knee joint replacement surgery), we conducted a linkage analysis of chromosome 2q using 16 polymorphic microsatellite markers at an average spacing of one marker every 8.5 cM.Results. Our results provide suggestive evidence for a locus at 2q31 with a maximum multipoint logarithm of the odds score (MLS) of 1.22 which increased to 2.19 in those families concordant for hip‐only disease (n = 311). This suggestive linkage was greater in male‐hip families (MLS = 1.57, n = 71) than in female‐hip families (MLS = 0.71, n = 132).Conclusions. Chromosome 2q is likely to contain at least one susceptibility locus for OA.

Objective. To examine 11 candidate genes as susceptibility loci for osteoarthritis (OA).Methods. A total of 481 families have been ascertained in which at least two siblings have had joint replacement surgery of the hip, or knee, or hip and knee for idiopathic OA. Each candidate gene was targeted using one or more intragenic or closely linked microsatellite marker. The linkage data were analysed unstratified and following stratification by sex and by joint replaced (hip or knee).Results. The analyses revealed suggestive linkage of the type IX collagen gene COL9A1 (6q12‐q13) to a subset of 132 families that contained affected females who were concordant for hip OA (female‐hip) with a P‐value of 0.00053 and logarithm of the odds (LOD) score of 2.33 [corrected P‐value of 0.0016, corrected LOD score of 1.85].Conclusions.COL9A1 may therefore be a susceptibility locus for female hip OA. In addition, there was weak evidence of linkage to HLA/COL11A2 (6p21.3) in female hip OA with a corrected P‐value of 0.016.

Background In independent linkage studies chromosome 2q11-q24 and chromosome 2q23-35 have previously been implicated as regions potentially harbouring susceptibility loci for osteoarthritis (OA).
Objective. To test chromosome 2q for linkage to idiopathic osteoarthritis.
Methods. Using a cohort of 481 OA families that each contained at least one affected sibling pair with severe end-stage disease (ascertained by hip or knee joint replacement surgery), we conducted a linkage analysis of chromosome 2q using 16 polymorphic microsatellite markers at an average spacing of one marker every 8.5 cM.
Results. Our results provide suggestive evidence for a locus at 2q31 with a maximum multipoint logarithm of the odds score (MLS) of 1.22 which increased to 2.19 in those families concordant for hip-only disease (n = 311). This suggestive linkage was greater in male-hip families (MLS = 1.57, n = 71) than in female-hip families (MLS = 0.71, n = 132).
Conclusions. Chromosome 2q is likely to contain at least one susceptibility locus for OA.

Objective. To examine 11 candidate genes as susceptibility loci for osteoarthritis (OA).
Methods. A total of 481 families have been ascertained in which at least two siblings have had joint replacement surgery of the hip, or knee, or hip and knee for idiopathic OA. Each candidate gene was targeted using one or more intragenic or closely linked microsatellite marker. The linkage data were analysed unstratified and following stratification by sex and by joint replaced (hip or knee).
Results. The analyses revealed suggestive linkage of the type IX collagen gene COL9A1 (6q12-q13) to a subset of 132 families that contained affected females who were concordant for hip OA (female-hip) with a P-value of 0.00053 and logarithm of the odds (LOD) score of 2.33 [corrected P-value of 0.0016, corrected LOD score of 1.85].
Conclusions.COL9A1 may therefore be a susceptibility locus for female hip OA. In addition, there was weak evidence of linkage to HLA/COL11A2 (6p21.3) in female hip OA with a corrected P-value of 0.016.

Abstract: Five samples of brown seaweed, collected from a variety of sites around northern Europe, were distributed to 14 laboratories for analysis of99Tc. Consistency in results between laboratories was found to be strongly correlated with concentration levels, with results diverging markedly at99Tc concentrations below 100 Bq·kg−1. No systematic differences were apparent between radiometric and mass based techniques but the results do suggest that the use of Re as a tracer may lead to an underestimation of99Tc levels.

The technique of high-resolution electron microscopy represents a powerful method for characterizing the microstructure of thin films and surfaces. We demonstrate its usefulness by reference to some recent studies of metals, semiconductors, and oxides, in particular, showing that it can be used to follow physical and chemical changes inducedin situby the electron beam orex situas a result of annealing or chemical treatment.

During a spring diatom bloom in a large marine experimental enclosure, there was a significant increase in cell dimensions of Skeletonema costatum. Over a period of 2 days, the mean value of the pervalvar axis increased from 6·7 to 12·3 μm. This change in size occurred during a period of rapid population growth. Cell diameter did not show the same dramatic increase, although there was a significant increase in cell diameter over the 18-day period of the experiment. Nutrient concentrations were high and nutrient limitation is unlikely to have been the reason for the change in cell length.

Two different methods of analyses were given for a complex experiment dealing with two sets of direct and crossover effects.

On the Channel Island of Jersey, a third of the total water requirements are obtained from groundwater sources. A reliable estimate of recharge is necessary for sustainable groundwater management. Past resource management has been limited, partly because the rate of recharge is uncertain.

Site occupancy has been determined using the channelling-enhanced microanalysis for a Ni3(Al, Ta) intermetallic compound with the L12-type crystal structure. It is shown that there is a large scattering of data points for [001] beam incidence compared with [111] beam incidence. The reasons for this difference are examined by simulating channelling electron distribution on the Al and Ni columns. It is concluded that the large scattering for the [001] beam incidence is due to the indistinguishable difference between channelling electron intensities on the Al and Ni columns.

The biologic effects of various chlorhexidine acetate (ClAc) solutions containing isopropyl alcohol, Synperonic NP8, and carmoisin were evaluated (1) following intraperitoneal (IP) administration in rats for 5 consecutive days followed by a 5-day recovery period, (2) by measuring the primary irritation of the skin by a patch-test technique on intact and abraded skin of rabbits, and (3) following instillation into the eyes or rabbits followed by washing 50% of the treated eyes with lukewarm water in order to evaluate ocular irritation. Physiologic saline solution served as the control article throughout the studies. There was a high incidence of deaths (i.e., 28/32 and 11/16 for ClAc solutions with and without Synperonic NP8, respectively) among rats receiving IP treatment at a dosage of 40 ml/kg per day for 5 consecutive days. No toxicologically significant treatment-related changes were observed in rats treated IP with either surfactant or isopropyl alcohol with Synperonic NP8. Toxicity of ClAc solution appears to be due to a chemically induced peritonitis with no evidence of systemic toxicity. ClAc solution or the respective surfactants elicited either no reaction or a mild dermal irritation in the rabbit. Likewise, ClAc solution with or without Synperonic NP8 and the three respective surfactants did not cause any significant ocular irritation changes that are considered of toxicologic significance. It is concluded that (1) the multiple IP administration of ClAc solution elicited a toxic response in rats, and thus, caution must be exercised when the solution is used for the purposes of peritoneal lavage, and (2) ClAc solution is a mild dermal and ocular irritant in the rabbit.

The urinary excretion of albumin was measured in insulin-dependent diabetics under ordinary conditions of life and in response to exercise. Possible mechanisms of exercise induced albuminuria in diabetics were also investigated. Under ordinary conditions of life the insulin-treated diabetics, as a group, had a higher mean urinary albumin excretion than normal controls; however, half of the diabetics had albumin excretion rates within the control range. A given exercise load (600 kpm/min for 20 min) produced an exaggerated albumin excretion in diabetics, particularly evident in the post-exercise period. The elevated urinary albumin excretion was due to an increased transglomerular passage of albumin, not to reduced tubular reabsorption. The increase was not associated with differences in blood pressure or urine flow between controls and diabetics. This exercise test has proved to be a suitable provocation test to unmask abnormalities in the glomerular handling of albumin that might not be recognisable at rest.

Two hundred and four men with impaired glucose tolerance (borderline diabetes) discovered in a screening examination have been observed for five years and repeated tests of glucose tolerance performed. By pre-determined criteria 27 men ‘worsened to diabetes’ and this metabolic deterioration was not significantly influenced by treatment with carbohydrate restriction with or without a daily dose of 50 mg phenformin. Of the baseline variables measured prior to treatment allocation only the blood glucose values were significantly predictive of ultimate worsening to diabetes.

Consideration of the shape and hydrogen bonding pattern of anentire guest unit, in the known 2:1:2 complex of 2′-hydroxy-2,4,4,7,4′-pentamethylflavan (1) with 1,4-dioxan and water, has indicated a structurally compatible guest,trans-1,4-bis(hydroxymethyl)cyclohexane (3b) which is selectively clathrated from a mixture with itscis isomer (3a). The new complex is triclinic, space group,P , witha=8.137(1),b=9.106(1),c=14.552(2) Å, α=93.56(1), β=94.08(1), γ=98.62(1)°, and two host and one guest molecule in the unit cell. A novel hydrogen bonded host-guest arrangement has also been found for host (1), involving ethanol and piperazine [triclinic, space groupP , witha=8.438(1),b=10.252(1),c=14.052(1) Å, α=71.28(1), β=89.72(1), γ=83.88(1)δ]; while for the 1:1 ether adduct of (1) the triclinic unit cell, space groupP , is approximately doubled in volume [a=8.309(2),b=10.546(3),c=26.664(6) Å, α=102.10(2), β=100.48(2), γ=81.04(2)°], there now being two crystallographically independent host-guest units involving ϕOH·OEt2 hydrogen bonds of length 2.71(1) Å and 2.77(1)Å. In the 2:1 complex of the isomeric host 2′-hydroxy-2,4,4,6,5′-pentamethylfavan (2) withN, N′-dimethylpiperazine (5) [triclinic space groupP , witha=7.411(1),b=10.143(3),c=15.109(3)Å, α=98.73(2), β=88.30(1), γ=109.72(2)°] the centrosymmetric chair-shaped guest molecule is clamped by two axially oriented ϕOH...N hydrogen bonds of length 2.759(3)Å.

Until recently it has been generally thought that a stagnant water column is a prerequisite to the formation of organic-rich deposits in deep-water marine sediments, a belief best exemplified by studies on the eastern Mediterranean sapropels. Many workers have assumed that, following the hydrological isolation of the deep waters, stagnation of the eastern Mediterranean basins and the concomitant development of anoxic conditions occurred before the deposition of the sapropelic layers1–10. Opposing arguments suggesting a role for increased marine productivity have, however, been put forward, both specifically with respect to the eastern Mediterranean sapropels11,12and more generally regarding deep-water organic-rich deposits13–15. We report here the discovery of sapropelic layers (>0.5% organic carbon)16in a recent sediment core from a deep-water site in the Guinea Basin. It is thought most unlikely that stagnant conditions could prevail in the water column at this site, and preliminary analyses of the sediments suggest that the organic-rich deposits have been a direct result of increased productivity in the overlying water column, the most recent occurring about 18,000 yr ago and coinciding with the last glacial maximum.

The band alignment of Atomic Layer Deposited SiO2on (InxGa1−x)2O3at varying indium concentrations is reported before and after annealing at 450 °C and 600 °C to simulate potential processing steps during device fabrication and to determine the thermal stability of MOS structures in high-temperature applications. At all indium concentrations studied, the valence band offsets (VBO) showed a nearly constant decrease as a result of 450 °C annealing. The decrease in VBO was −0.35 eV for (In0.25Ga0.75)2O3, −0.45 eV for (In0.42Ga0.58)2O3, −0.40 eV for (In0.60Ga0.40)2O3, and −0.35 eV (In0.74Ga0.26)2O3for 450 °C annealing. After annealing at 600 °C, the band alignment remained stable, with <0.1 eV changes for all structures examined, compared to the offsets after the 450 °C anneal. The band offset shifts after annealing are likely due to changes in bonding at the heterointerface. Even after annealing up to 600 °C, the band alignment remains type I (nested gap) for all indium compositions of (InxGa1−x)2O3studied.

Off-axis electron holography is a powerful method for providing quantitative micromagnetic structure to nanometer-scale resolution. One of the main challenges in determining magnetic induction from reconstructed phase images is the separation of phase shifts due to electrostatic and thickness effects from magnetostatic effects. We have used in-situ magnetization reversal to remove electrostatic and thickness effects which would otherwise prevent quantification of the induction. The Philips CM200-FEG microscope which was used for the holography described here is equipped with a powerful mini-lens below the specimen enabling 2nm spatial resolution (∼5nm phase resolution) and only a small residual field at the sample. In addition, the objective lens field versus current has been calibrated so that external vertical fields over a wide range of values may be applied to the sample. Tilting the sample in the presence of the vertical field has the effect of ‘applying an inplane component. This combination of high spatial resolution, quantitative analysis and in situ capabilities allows for the study of individual defects and provides experimental input for comparison with simulations.

TEM has not traditionally contributed to characterization of semiconductor junctions, except for some intriguing results by Perovic, Hull and Alvis where highly doped layers gave contrast under very specific sample preparation and imaging conditions. Since electron holography is sensitive to the phase of the electron wavefront that has passed through the sample, it has the potential to provide voltage contrast. In principle, given its inherent two-dimensional and quantitative character, electron holography is a strong candidate for analysis of semiconductor device junctions.The sample for the work reported here was one of a group of test specimens fabricated at IBM for a dopant metrology round-robin comparison to evaluate various profiling methods. The substrate was <100> p-type silicon, boron-doped at 11-25 Ω-cm-1. The test structure was fabricated using low- temperature epitaxial growth and consisted of an abrupt p-n junction, formed by abutting 1020cm-3doped regions of boron and phosphorus

TEM has not traditionally contributed to characterization of semiconductor junctions, except for some intriguing results by Perovic, Hull and Alvis where highly doped layers gave contrast under very specific sample preparation and imaging conditions. Since electron holography is sensitive to the phase of the electron wavefront that has passed through the sample, it has the potential to provide voltage contrast. In principle, given its inherent two-dimensional and quantitative character, electron holography is a strong candidate for analysis of semiconductor device junctions.The sample for the work reported here was one of a group of test specimens fabricated at IBM for a dopant metrology round-robin comparison to evaluate various profiling methods. The substrate was <100> p-type silicon, boron-doped at 11-25 Ω-cm-1. The test structure was fabricated using low- temperature epitaxial growth and consisted of an abrupt p-n junction, formed by abutting 1020cm-3doped regions of boron and phosphorus

The relationship between blood pressure and the blood sugar concentration measured two hours after a 50 g oral glucose load has been examined in two population surveys — the Whitehall and Bedford Surveys. In the Whitehall Survey, which was conducted in men above the age of 40, there was a positive, significant correlation between blood sugar and blood pressure (systolic and diastolic) which was independent of common associations with age, body mass index (BMI) and heart rate. In the Bedford Survey, systolic blood pressures were significantly higher in newly detected diabetics and borderline diabetics, both men and women, than in normoglycaemic controls after adjustment of blood pressures for age and BMI. However, in the stratified random sample of the cooperating Bedford population, only amongst women was the blood sugar significantly and independently correlated with the systolic blood pressure. Evidence is presented and discussed that autonomic, neurohumoral factors may play some part in the pathogenesis of maturity onset diabetes.