Conduction band states of transition metal (TM) high-k gate dielectrics as determined from X-ray absorption spectra

This paper uses X-ray absorption spectroscopy to study the electronic structure of the high-k gate dielectrics including TM and RE oxides. The results are applicable to TM and rare earth (RE) silicate and aluminate alloys, as well as complex oxides comprised of mixed TM/TM and TM/RE oxides. These studies identify the nature of the lowest conduction band d^* states, which define the optical band gap, E_g, and the conduction band offset energy with respect to crystalline Si, E_B. E_g and E_B scale with the atomic properties of the TM and RE atoms providing important insights for identification high-k dielectrics that meet performance targets for advanced CMOS devices.     

Construction experiences with SSC collider dipole magnets atFermilab

Full length and short model SSC (Superconducting Super Collider) 50 mm bore dipoles are being built and tested at Fermilab. The mechanical design of these magnets has been determined from experience with the construction of previous superconducting magnets. Construction experience includes coil fabrication, ground insulation, instrumentation, collaring, and yoke assembly. Fabrication techniques are explained, and construction problems and their solutions are reviewed. The relationship of short to long model construction is discussed     

Effect of pulmonary artery stenoses on the cardiopulmonary response to exercise following repair of tetralogy of Fallot

Data from exercise tests, echocardiograms, and lung perfusion scans were analyzed to determine whether the excessive minute ventilation (VE) often encountered among patients with tetralogy of Fallot is due to ventilation-perfusion mismatch secondary to branch pulmonary artery stenoses. Patients with branch PA stenoses had lower peak oxygen consumptions and higher VE during exercise than did patients without stenoses, and a strong correlation existed between the degree of pulmonary blood flow maldistribution on lung perfusion scan and the amount of excessive VE during exercise.     

Metal binding properties of poly[N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine methacrylate]

Summary When incorporated into a polymer hydrogel, the metal chelator, N,N,N,N-tetrakis(2-hydroxypropyl)ethylenediamine (THPED), retains its metal binding properties. The resultant poly(THPED methacrylate) homopolymer is a polybase with displacement binding constants for copper (II) and zinc(II) of-3.11 and-6.55, respectively, as compared to values for THPED of-3.83 and-7.44. The chelating capacity of the polymer for various divalent metal ions at pH 5.5 follows the order Cu>Cd>Co>Zn>Mn, while calcium and magnesium do not bind. Metal ion release curves indicate that after 30 hours, Cd(II), Co(II), Zn(II), and Mn(II) are released at a slow, steady rate, while Cu(II) is not released under experimental conditions.     

Environmental Hydrogen Embrittlement of G41400 and G43400 Steel Bolting in Atmospheric Versus Immersion Services

This article is based on a review of data in the literature and those released by the California Department of Transportation and reported by the Bureau of Safety and Environmental Enforcement (BSEE). In 2013, hot dip galvanized (HDG) threaded rods failed due to environmental hydrogen embrittlement (EHE) cracking on the San Francisco–Oakland Bay Bridge. These rods were made of G41400 steel, conforming to ASTM A354 Grade BD (39 HRC max). All 32 EHE failures occurred in the bottom threads that had been immersed in pools of water, inadvertently, under no stress, for over four years before they were pretensioned. Several failure analysis reports stated that they failed due to EHE cracking because they were pretensioned while being immersed in water. This is erroneous, however, because one or more of the failed rods were not immersed in water during pretensioning and afterward. Conversely, hydrogen from metal corrosion of the HDG BD rods can diffuse into them under no stress while corroding in standing water for several years. The EHE cracking occurred when subsequently pretensioned. None of about 4000 threaded ends of HDG BD rods that have been exposed only to marine atmosphere (but not immersed in water) has failed in three to four years in service under a pretension load. These data are compared with recent EHE cracking of G43400 bolting in subsea oil production facilities in the Gulf of Mexico, reported by the BSEE.

     

Ergonomic design of ticket barriers for use by the travelling public

This paper describes a two-stage study of the performance and acceptability of automatic ticket barriers. The aim of the research was to provide information to both manufacturers and transport operators to aid them in specifying equipment which would meet requirements for security and passenger flow and at the same time be acceptable, convenient and safe for use by passengers.

Stage one consisted of field studies at three railway stations and a laboratory evaluation of five types of ticket barrier. The field studies were undertaken to record and identify the characteristics of users and the type and frequency of problems they encountered. The laboratory trials consisted of objective and subjective evaluations of the four barriers by selected classes of user. Stage two consisted of a detailed study of certain features of barrier design, identified in stage one, including the type and speed of ticket checking, barrier dimensions and equipment for luggage handling. Results of the research have enabled design recommendations to be drawn up for use in the specification of future ticket barrier design.     

Powered domestic lawnmowers: design for safety

The paper describes a detailed accident investigation carried out by the Institute for Consumer Ergonomics for the Consumer Safety Unit at the Department of Trade. As such it serves to illustrate the application of two specific research techniques (i) analysis of product related accident data, and (ii) ergonomics evaluation of current models - and shows how these may be used to help in defining standards and criteria for the design of safer products. The study identified lawnmower features and activities associated with accidents recorded by the Home Accident Surveillance System. Ergonomics appraisal by expert assessment and user trials highlighted hazards associated with currently available powered lawnmowers. Performance criteria for safer design of selected features were developed with the aim of overcoming these hazards. At the end of the study liaison was sought with manufacturers to discuss how the results from the work could be used to effect.     

Tracking and characterizing the head motion of unanaesthetized rats in positron emission tomography

Positron emission tomography (PET) is an important in vivo molecular imaging technique for translational research. Imaging unanaesthetized rats using motion-compensated PET avoids the confounding impact of anaesthetic drugs and enables animals to be imaged during normal or evoked behaviour. However, there is little published data on the nature of rat head motion to inform the design of suitable marker-based motion-tracking set-ups for brain imaging—specifically, set-ups that afford close to uninterrupted tracking. We performed a systematic study of rat head motion parameters for unanaesthetized tube-bound and freely moving rats with a view to designing suitable motion-tracking set-ups in each case. For tube-bound rats, using a single appropriately placed binocular tracker, uninterrupted tracking was possible greater than 95 per cent of the time. For freely moving rats, simulations and measurements of a live subject indicated that two opposed binocular trackers are sufficient (less than 10% interruption to tracking) for a wide variety of behaviour types. We conclude that reliable tracking of head pose can be achieved with marker-based optical-motion-tracking systems for both tube-bound and freely moving rats undergoing PET studies without sedation.     

The Effect of Increasing Fruit and Vegetable Consumption on Overall Diet: A Systematic Review and Meta-analysis

Increasing fruit and vegetable (FV) consumption is associated with reduced risk of major diseases. However, it is unclear if health benefits are related to increased micronutrient intake or to improvements in overall diet profile.

This review aimed to assess if increasing FV consumption had an impact on diet profile. In the systematic review, 12 studies revealed increases in micronutrient intakes, whilst the meta-analysis confirmed macronutrient findings from the systematic review showing no significant difference between the intervention and control groups in energy (kcals) in seven studies (mean difference = 1 kcals [95% CI = ?115, 117]; p = 0.98), significant decreases in total fat (% energy) in five studies (Mean difference = ?4% [95% CI = ?5, ?3]; p = < 0.00001) and significant increases in fiber in six studies (Mean difference = 5.36 g [95% CI = 4, 7]; p = < 0.00001) and total carbohydrate (% energy) in four studies (Mean = 4% [95% CI= 2, 5]; p = < 0.00001).

In conclusion, results indicate that increased FV consumption increases micronutrient, carbohydrate and fiber intakes and possibly reduces fat intake, with no overall effect on energy intake. Therefore health benefits may act through an improvement in overall diet profile alongside increased micronutrient intakes.     

Predicting Mechanical Strength of In-Use Firefighter Protective Clothing Using Near-Infrared Spectroscopy

The exact lifespan of in-use firefighter protective clothing is difficult to predict due to the large variations in use between individual garments. Furthermore, testing methods used to evaluate new protective clothing are destructive in nature and could not be applied to in-use garments. Various non-destructive techniques have been proposed for the evaluation of in-use clothing, each possessing its own advantages and disadvantages. The ability of near-infrared spectroscopy to predict the tensile strength of thermally aged fabrics used in protective clothing for wildland firefighters and other workers is investigated here. Fabrics were exposed to heat fluxes from 10 kW/m² to 40 kW/m² for various durations using the cone calorimeter, after which the tensile strength of the fabrics was measured. Temperatures measured during the exposures and results of thermal gravimetric analysis tests were used to interpret changes in tensile strength. Multivariate linear regression was used to develop correlations between the tensile strength and the reflectance values measured between 1500 nm and 2500 nm for new and thermally aged fabrics. It was found that models based on reflectance measurements made at as few as three wavelengths could be used to estimate the tensile strength of the thermally aged specimens.