Preparations for Variable-Gravity Regolith Penetration with an Ultrasonically-Active Probe

The set of experiments proposed in this paper intend to investigate the properties of ultrasonic penetration through granular materials in hypergravity. As part of ESA's 6 th 'Spin Your Thesis' campaign, the University of Glasgow will be allowed to use the Large Diameter Centrifuge at the ESTEC facilities in Noordwijk, Netherlands, to achieve these hypergravity conditions. This paper describes the progress of the design and manufacture of the experimental apparatus, analysis of structural integrity to insure the rig can be subjected to the rigors of hypergravity, and discussion of the anticipated results and implications

Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location

Push-and-Twist Drillstring Assemblies

Deep drilling using a rigid drillstring requires the assembly and disassembly of multiple drill pipes. The interfaces between these pipes provide a challenge for automation because they must transmit large drilling forces and movements while, at the same time, minimise the actions and forces that are needed to make or break the interface. A geometry which can address these requirements has been suggested by the authors. This approach would use a push-and-twist bayonet system to engage drill pipes, with torque transmission through the bayonet studs. A variety of L-shaped and T-shaped bayonet paths have been proposed to ensure that separation of specific drill pipes can be achieved through a combination of clockwise and counter-clockwise rotation and single-point clamping. Sustained drills into a variety of media are used to show that percussive impulses are transmitted across the interface, whilst ensuring that the drill interface is able to withstand the shock loading associated with hammer-drilling. These tests are repeated and contrasted to control experiments using a single-piece control drillstring, which allows the performance of the interface and any degradation over time to be quantified. Results suggest that the bayonet-style connection performs well with no significant performances losses encountered or structural degradation noted

Trellis phase codes for power-bandwith efficient satellite communications

Support work on improved power and spectrum utilization on digital satellite channels was performed. Specific attention is given to the class of signalling schemes known as continuous phase modulation (CPM). The specific work described in this report addresses: analytical bounds on error probability for multi-h phase codes, power and bandwidth characterization of 4-ary multi-h codes, and initial results of channel simulation to assess the impact of band limiting filters and nonlinear amplifiers on CPM performance

Gamma-ray transfer and energy deposition in supernovae

Solutions to the energy-independent (gray) radiative transfer equations are compared to results of Monte Carlo simulations of the \Ni\ and \Co\ radioactive decay \GR\ energy deposition in supernovae. The comparison shows that an effective, purely absorptive, gray opacity, \KG\ \sim (0.06 \pm 0.01)Y_e cm^2 g^{-1}, where Y_e is the total number of electrons per baryon, accurately describes the interaction of \GRs\ with the cool supernova gas and the local \GR\ energy deposition within the gas. The nature of the \GR\ interaction process (dominated by Compton scattering in the relativistic regime) creates a weak dependence of \KG\ on the optical thickness of the (spherically symmetric) supernova atmosphere: The maximum value of \KG\ applies during optically thick conditions when individual \GRs\ undergo multiple scattering encounters and the lower bound is reached at the phase characterized by a total Thomson optical depth to the center of the atmosphere \te\ \LA\ 1. Our results quantitatively confirm that the quick and efficient solution to the gray transfer problem provides an accurate representation of \GR\ energy deposition for a broad range of supernova conditions

Parents’ Ethnotheories of Maladaptive Behavior in Young Children

Parents’ culturally influenced belief systems, or ethnotheories, are critical components of children’s socialization. Beliefs about children’s desirable characteristics motivate specific parenting activities and moderate the effectiveness of childrearing practices. However, relatively little attention has been given to parents’ ethnotheories of children’s undesirable behavior. From a few studies, we know that parents have culturally specific theories about the nature and management of children’s maladaptive behavior that motivate their socialization practices. In this review, we identify gaps in the research and suggest that qualitative studies of parents’ ethnotheories about the nature and management of children’s deviant behavior have strong theoretical, empirical, and practical benefits for developmental science.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151344/1/cdep12330.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151344/2/cdep12330_am.pd

Coupled-mode theory for photonic band-gap inhibition of spatial instabilities

We study the inhibition of pattern formation in nonlinear optical systems using intracavity photonic crystals. We consider mean-field models for singly and doubly degenerate optical parametric oscillators. Analytical expressions for the new (higher) modulational thresholds and the size of the "band gap" as a function of the system and photonic crystal parameters are obtained via a coupled-mode theory. Then, by means of a nonlinear analysis, we derive amplitude equations for the unstable modes and find the stationary solutions above threshold. The form of the unstable mode is different in the lower and upper parts of the band gap. In each part there is bistability between two spatially shifted patterns. In large systems stable wall defects between the two solutions are formed and we provide analytical expressions for their shape. The analytical results are favorably compared with results obtained from the full system equations. Inhibition of pattern formation can be used to spatially control signal generation in the transverse plane

Is comparability of C-14 dates an issue?: A status report on the fourth international radiocarbon intercomparison

For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Guiliksen and Scott 1995; Scott et al. 1997).<br/> In this report, we provide an update on the current C-14 laboratory intercomparison and reflect on future issues linked to the laboratory intercomparison program, not least those resulting from a significant growth in the number of accelerator mass spectrometry (AMS) facilities providing routine dating of small samples (milligram size)

Just picking it up? Young children learning with technology at home

We describe a two-year empirical investigation of three- and four-year-old children's uses of technology at home, based on a survey of 346 families and 24 case studies. Using a sociocultural approach, we discuss the range of technologies children encounter in the home, the different forms their learning takes, the roles of adults and other children, and how family practices support this learning. Many parents believed that they do not teach children how to use technology. We discuss parents' beliefs that their children 'pick up' their competences with technology and identify trial and error, copying and demonstration as typical modes of learning. Parents tend to consider that their children are mainly self-taught and underestimate their own role in supporting learning and the extent to which learning with technology is culturally transmitted within the family