Search

Carbon nanotubes (CNTs) have unique properties with promise to outperform the electrical characteristics of bulk copper, giving rise to its primary driver for use in electronic devices. The challenge still hindering their full exploitation stems from an inability to manufacture them to long lengths, resulting in a requirement to align and entwine them into a yarn or wire. There have been several methods presented in achieving this, however, the common disadvantage has been that they are only applicable to specific types and morphologies of CNTs. In the work reported here, using electrospinning as a universally applicable route for any CNT type, we re-engineer and optimise the various formulation, fabrication and processing steps required to manufacture CNT wires. Through a series of investigations using a materials agnostic approach, we experimentally probe the choice of solvent, surfactant and thermal treatment temperature of the CNT inks, demonstrating the CNT-type optimum using a range of commercially available single- double- and multiwalled CNTs. Finally, this allowed us to develop and probe an electrical conditioning process to further enhance the electrical performance, achieving the highest reported un-doped electrical conductivity of 36,000 S⋅m− 1 for electrospun CNT wires, or a specific conductivity of 0.2×106S·m−1/g·cm−3.

Research in the last few decades has shown that obesity and its metabolic complications have important effects on the respiratory system. There is ample and growing evidence that obesity affects lung function in otherwise healthy adults and children. Obesity exerts an additional load upon the respiratory system, changing the balance of pressures between the inward recoil of the lung and the outward pressure of the chest. This has major consequences on lung volumes, airway mechanics, airway closure, expiratory flow limitation, ventilation distribution, airway hyperresponsiveness, and exhaled nitric oxide levels. Many of the changes in lung function due to obesity are likely to contribute to respiratory symptoms; however, there are important differences in the effect of obesity on lung function between children, adolescents, and adults. Therefore understanding the effects of obesity on lung function throughout the lifespan is imperative to understanding present and future effects of obesity on respiratory health.

In humanitarian emergency settings there is need for low cost and rapidly deployable interventions to protect vulnerable children, in- and out-of-school, from diarrhoeal diseases. Handwashing with soap can greatly reduce diarrhoea but interventions specifically targeting children's handwashing behaviour in humanitarian settings have not been tested. Traditional children's handwashing promotion interventions have been school-focused, resource-intensive and reliant on health-based messaging. However, recent research from non-humanitarian settings and targeting adults suggests that theory-based behaviour change interventions targeting specific motives may be more effective than traditional handwashing interventions. In this proof-of-concept study we test, for the first time, the distribution of a modified soap bar, designed to appeal to the motives of play and curiosity, in a household-level, rapidly deployable, handwashing promotion intervention for older children in a humanitarian setting - an internally displaced persons camp in Iraqi Kurdistan. Out of five total blocks within the camp, one was assigned to intervention and one to control. 40 households from each assigned block were then randomly chosen for inclusion in the study and the practice of handwashing with soap at key times was measured at baseline and four weeks after intervention delivery. Children in intervention households received transparent soaps with embedded toys, delivered within a short, fun, and interactive household session with minimal, non-health-based, messaging. The control group received plain soap delivered in a short standard, health-based, hygiene promotion session. At the 4-week follow-up, children in the intervention group were 4 times more likely to wash their hands with soap after key handwashing occasions than expected in the counterfactual (if there had been no intervention) based on the comparison to children in the control group (adjusted RR = 3.94, 95% CI 1.59-9.79). We show that distributing soaps with toys embedded inside, in a rapidly deployable intervention, can improve child handwashing behaviour in a humanitarian emergency context. Further studies are needed to determine the longer-term behavioural and health impact of such an intervention when delivered at a greater scale in a humanitarian context.

We present a first-draft digital reconstruction of the microcircuitry of somatosensory cortex of juvenile rat. The reconstruction uses cellular and synaptic organizing principles to algorithmically reconstruct detailed anatomy and physiology from sparse experimental data. An objective anatomical method defines a neocortical volume of 0.29 ± 0.01 mm3 containing ∼31,000 neurons, and patch-clamp studies identify 55 layer-specific morphological and 207 morpho-electrical neuron subtypes. When digitally reconstructed neurons are positioned in the volume and synapse formation is restricted to biological bouton densities and numbers of synapses per connection, their overlapping arbors form ∼8 million connections with ∼37 million synapses. Simulations reproduce an array of in vitro and in vivo experiments without parameter tuning. Additionally, we find a spectrum of network states with a sharp transition from synchronous to asynchronous activity, modulated by physiological mechanisms. The spectrum of network states, dynamically reconfigured around this transition, supports diverse information processing strategies., The work was supported by funding from the EPFL to the Laboratory of Neural Microcircuitry (LNMC) and funding from the ETH Domain for the Blue Brain Project (BBP). Additional support was provided by funding for the Human Brain Project from the European Union Seventh Framework Program (FP7/2007-2013) under grant agreement no. 604102 (HBP). Further funding came from The Gatsby Charitable Foundation ; the Cajal Blue Brain Project, Ministerio de Economia y Competitividad Spanish Ministry of Education and Science ; and an EPFL-Hebrew University Collaborative Grant . In the years 2005–2009, the Blue Gene/L system was funded by the EPFL . Financial support for the subsequent CADMOS Blue Gene/P and Blue Gene/Q systems was provided by the Canton of Geneva, Canton of Vaud, Hans Wilsdorf Foundation , Louis-Jeantet Foundation , University of Geneva , University of Lausanne , and École Polytechnique Fédérale de Lausanne . The BlueBrain IV BlueGene/Q system is financed by ETH Board Funding to the Blue Brain Project as a National Research Infrastructure and hosted at the Swiss National Supercomputing Center (CSCS). A large proportion of the data used in this study was generated at the Weizmann Institute for Science, Israel between 1996 and 2002 through the support of Thomas McKenna from the Office of Naval Research, USA.

Extraordinary rates of biodiversity loss, coupled with rising human population and consumption rates, threaten the sustainability of Earth’s life support systems. An inclusive wealth framework that considers the current and future stocks and flows of human and Earth system assets, including biodiversity, provides one means of examining progress toward sustainability. Successful efforts to meet the needs of current and future generations will require a global perspective that considers the complex relationships between biodiversity, poverty, and equity as well as a temporal perspective that considers the nonlinear dynamics and potential tipping points in human and Earth systems.

Publisher Summary This chapter provides information on equipment and procedures for milling ceramic material. There are two broad types of ceramic raw materials that require milling: lumpy and powdered ceramics. Powdered raw materials usually come from chemical processes where the material in solution chemically reacts to form particles in suspension. An important class is Bayer alumina that starts as bauxite. The Hall Cell fuses the bauxite with the cryolite flux forming a sodium aluminate that is then leached with caustic and washed to produce a moderately pure alumina powder. Production milling is sometimes done dry as it avoids a separate drying step. Dry milling also avoids the formation of hard agglomerates as there is no liquid present. Dry milled ceramics are usually used in pressing operations to make a shape and to consolidate the particles. Crushing and milling are sequential processes for particle-size reduction. Wet milling is more frequently applied in the laboratory than dry milling. Wet milling is usually used to make a coarse-grained slip or a fine-grained slip. A slip consists of a liquid vehicle—usually water—and suspended ceramic particles. Fine-grained particles are held in suspension by dispersants and other surface-active chemicals.

This chapter covers analytical methods used to characterize ceramic materials, slip properties, microscopy, and physical properties of ceramic materials. Emission spectra are more widely used for the analysis of ceramics than absorption spectra. While atomic absorption was an important absorption method for chemical analyses, it has largely been superseded by induction-coupled plasma (ICP)—an emission technique. Thermal gravimetric analysis (TGA) measures the change in weight as the sample is heated in an atmosphere of choice. The equipment used is capable of reaching above 1500℃ and usually has an atmosphere of air, nitrogen, or argon. TGA is useful in studies such as binder burnout, desorption, dehydration, and thermal decomposition. Measuring thermal conductivity requires both thermal diffusivity and specific heat. The laser pulse method easily measures diffusivity while calorimetry determines specific heat. Coarse particles are best measured by screening. Fine particles are usually measured by light diffraction or dynamic light scattering (DLS). Other techniques are based on settling either with or without a centrifuge. Doppler shift measures very fine particles due to Brownian motion.

This chapter focuses on several equipment available for mixing coarse-grained materials. One such equipment is mullers, which can be used for grinding and mixing depending on the hardness of the material and the weight of the muller wheels. Mullers have a bottom port that can be opened to discharge the mix, with the plow forcing the mix into the port. Bearings are out of the abrasive mix, thereby making the equipment durable. Another equipment is a sigma blade mixer, which is a trough with two sigma-shaped arms that rotate to blend the mix. One can use either pug or sigma blades, but they are not interchangeable without dismantling the mixer. Two blades intertwine while rotating, thereby resulting in a moderate shearing intensity and homogenization. The trough tips to dump the batch, thereby providing for easy clean up. The seals and bearings are in the batch during mixing and require maintenance. In this mixer, the shearing effect is not intense enough for fine-grained batches, but relatively coarse mixes can be satisfactority mixed. Another equipment is ribbon blenders, which are horizontal troughs with a small number of helical blades that rotate around the trough axis. Like the sigma blade, the trough tips to dump the batch. Mixing is gentle, which makes ribbon blenders useful for premixing batches or for calcining mixes.

This chapter describes how material selection and processing affects the properties of the final ceramic. Different materials have unique intrinsic properties that derive from the chemical bonding and crystal structure of the lattice, and the initial choice of powdered and granular materials depends upon these properties. Chemical properties determine which phase will be stable at a particular temperature as well as the reactivity of a given application. The effect of the starting materials on the final microstructure after sintering is of great concern. There do exist fine- and coarse-grained materials. However, other considerations include sinterability, final grain size, shrinkage, porosity, and flaw populations. These properties are often characteristics of the starting materials. Bonding in many ceramics is very strong. When a crystal fractures, the surface bonds are broken and become extremely reactive. Surfaces are very strong absorbents. High-surface-area powders can absorb significant quantities of gases, which are difficult to remove. These types of powders have gained widespread use, thereby making gas desorption an issue.

A good baseline of information has been collected for tundra swans on the Arctic Coastal Plain of Alaska, primarily in the oil-field region. The tundra swan (Cygnus c. columbianus) is the most numerous and widely distributed North American swan, nesting primarily in tundra habitats within 200 km of the seacoast from north-central Canada to southwestern Alaska. Studies to date have allowed biologists to annually monitor distribution of breeding swans, swan population levels, and swan productivity. These studies have also assisted with the placement of oil-field facilities. Habitat use patterns during nesting and brood-rearing, the degree of late-season mortality, and the distribution and habitat requirements of non-breeding swans are less readily studied by aerial survey, and thus are less well known. Tundra swans have benefited greatly from the attention they have received from the regulatory, development, and research communities on the North Slope of Alaska. Cooperation between public-resource agencies and oil companies has resulted in the development of protective strategies advantageous for swans, particularly for breeding pairs. Sound stewardship of this important continental migratory bird resource will depend on these conservation efforts continuing in the future.

The Real Business Cycle (RBC) research program has grown specularly over the last decade, as its concepts and methods have diffused into mainstream macroeconomics. Yet, there is increasing skepticism that technology shocks are a major source of business fluctuations. This chapter exposits the basic RBC model and shows that it requires large technology shocks to produce realistic business cycles. While Solow residuals are sufficiently volatile, these imply frequent technological regress. Productivity studies permitting unobserved factor variation find much smaller technology shocks, suggesting the imminent demise of real business cycles. However, we show that greater factor variation also dramatically amplifies shocks: a RBC model with varying capital utilization yields realistic business cycles from small, nonnegative changes in technology.

This chapter explores possible avenues that are available, or may be developed, for the manipulation of natural enemies to improve their effectiveness in controlling pests. The chapter also considers the natural enemies in the context of a rational management program that explores the appropriate use of all available insect control methods. Augmentation of natural enemies to effect suppression of pest populations has received considerable attention over the years. Inundative releases rely mainly on the agents released, not on their progeny, to effect control; whereas inoculative releases rely on an increase in the initial natural enemy populations that can suppress subsequent pest generations. Inundative releases may be timed so that both immediate control and subsequent progeny production contribute to pest suppression. Effective manipulation of natural enemies requires a thorough knowledge of their biology and host associations. Background information may be gained through laboratory studies. However, it is imperative that such data be followed by extensive biological studies in the field. The level of control achieved in an augmentation program may be a function of a myriad of interacting factors. Primary factors include the availability of hosts and host–parasitoid synchrony, the weather conditions during the release of natural enemies involving the effects of environmental factors on foraging, influence of habitat type, chemical pesticide usage, and fitness of laboratory-reared parasitoids.

Research efforts have been under way for over twenty years aimed at investigating and understanding the use of conducting polymers to monitor volatile chemicals. In some cases, this work has led to commercial exploitation. The mechanisms by which interaction between the polymer surface and the volatile chemicals give rise to electrical changes in the polymer are not fully understood and this paper will briefly review this fundamental topic. It will go on to show that major advantages accrue from interrogating conducting polymers using high frequency techniques rather than the de methods used by most researchers. These advantages will be quantified by reference to simple lumped circuit models that have been built for a sensor configuration in use by the present authors. In addition, comparisons between the dielectric properties of the sensors predicted by the model and from a number of measurements will be used to justify the model structure. The paper will also discuss conducting polymer array technology, methods of interrogating such sensor arrays and their deployment as part of new sampling strategies aimed at eventually achieving ppt levels of detection of contamination in water using headspace analysis.

The author addresses a number of issues related to the potential of computer graphics and animation systems to enhance or reenforce the process of artistic creativity and evolution. Various constraints imposed by computer graphics systems are explored and the major psychological characteristics of creative thinking are described. Issues are raised regarding the impact on these characteristics by the properties and process inherent in computer graphics and animation systems and their potential as agents for personal evolution in the arts.

Publisher Summary This chapter discusses the excited states of 4 He studied with the polarized proton capture reaction. It presents a summary of lowest excited states of 4 He obtained from resonance analyses of and reactions. The negative parity levels are consistent in spin and approximate location with the 1p1s −1 states predicted by the shell model. Positive parity states are expected to be composed partly of 1p–1h and partly of 2p–2h excitations. For a self-conjugate nucleus such as 4 He, E1 transitions to the ground state are allowed only from T = 1, 1 − levels. The two T = 1, 1 − levels postulated at 27.k and 30.5 MeV are expected to dominate the characteristics of the EL radiation in nucleon capture reactions, which form 4 He. These states comprise the giant E1 resonance of 4 He. The presence of third and fourth degree Legendre polynomials P 3 , P 4 , in the gamma-ray angular distribution is evidence for E2 radiation, which is thought to reflect a T = 0, 2 + state in the region of 33 MeV in 4 He. The spin direction for the protons could be set either up or down by switching the rf transitions in the polarized source.

SUMMARY During the past eight years the Andritz continuous pressure filter, (multi roll filter), has been used to de-water fine coal tailings arising from coal washing plants throughout the world. This paper describes the method of operation of the continuous pressure filter and tabulates a range of parameters obtained from operating units.

By using computer simulations and recently developed statistical models this paper illustrates the variation which might be expected when estimating skewness and kurtosis from uncorrelated or correlated observations of Gaussian or non-Gaussian processes. Results of Monte-Carlo simulations to illustrate the sampling variation of skewness and kurtosis from a wide range of Gaussian and non-Gaussian distributions for both uncorrelated and correlated data are compared with actual measurements of skewness and kurtosis taken from two engineering processes.

Publisher Summary This chapter presents molecular beam as a tool in technical applications, such as in the measurement of magnetic fields, the measurement of acceleration, the measurements of length, information storage, and isotope separation. The observations should be made on the molecules of the beam so that when the interference fringes pass over the beam, the number of molecules that are affected by the light will undergo a periodic variation. Then only Doppler effect and the resonance line width of the molecules of the beam limit the path difference, which can be tolerated in the interferometer. The chapter also discusses the sources of neutral molecular beams. The detectors of neutral beams is described in the chapter that falls into two broad categories; those which give a direct measure of the beam intensity—for instance, by ionizing the molecules and measuring the resultant ion current—and those in which the effect of the beam on some suitably sensitive device, such as a highly refined manometer, gives an indirect measure of the beam intensity. The chapter assists new users of molecular beams by providing the descriptions of more or less conventional molecular- beam components with suggestions for future development.