A note on commuting graphs for symmetric groups

The commuting graph C(G;X) , where G is a group and X a subset of G, has X as its vertex set with two distinct elements of X joined by an edge when they commute in G. Here the diameter and disc structure of C(G;X) is investigated when G is the symmetric group and X a conjugacy class of G

Using the ICF and psychological models of behavior to predict mobility limitations

Aims to test the ability of a model that integrates the theory of planned behavior (TPB) into the International Classification of Functioning Disability and Health (ICF) to predict walking limitations in adults awaiting hip or knee replacement surgery. Study Design and Participants: Cross-sectional structural equation modeling study of activity limitations in 190 adults. Method: A postal questionnaire measuring the TPB, ICF and walking limitations. Results: The integrated model accounted for more variance in activity limitations (57%) than either the TPB or ICF alone. Control beliefs (TPB) significantly mediated the relationship between impairment (ICF) and activity limitations. Conclusions: The integrated model provides an interdisciplinary theoretical framework that identifies intervention targets to effect reductions in disability without the need for concomitant reductions in impairment

Chalcopyrite Semiconductors as Sources for Terahertz Spectroscopy

This dissertation summarizes a first effort to address the suitability of chalcopyrite structured semiconductors for efficient and broadband terahertz (THz) pulse emission by optical rectification. The experiments demonstrate that ZnGeP2, a chalcopyrite semiconductor showing improved growth quality in recent decades [1,2], is a promising source for THz spectroscopy while also addressing general fundamental questions concerning the nonlinear generation process in chalcopyrite semiconductors. Beyond ZnGeP2, the potential of other chalcopyrite structured semiconductors for THz emission is examined in the context of calculated phase-matching characteristics, onset pump wavelength of multiphoton absorption, and tabulated second-order nonlinear coefficients. Based on these, CdGeP2 is determined to show particular promise among semiconductors as a THz source when pumped at or near the fiber laser line of 1.55 im. The orientation dependence of THz optical rectification efficiency is examined in tetragonal birefringent ZnGeP2, compared to that of cubic GaP, and modeled based on the second-order nonlinear tensor, while accounting for birefringence. These results demonstrate the significant effects of birefringence on THz emission efficiency while defining the most efficient orientations for generation and can be generalized to other chalcopyrite semiconductors; the general approach is applicable to other uniaxial birefringent crystals. Experimental mapping of generated THz pulses is presented over a broad pump tuning range (1120-2480 nm) in 3 mm thick ZnGeP2 crystals. This mapping, for two distinct and efficient orientations, demonstrates the moderate angle tunability of phase mismatch achievable in chalcopyrite crystals; the data also continuously demonstrate the effects of phase mismatch on the temporal and spectral THz pulse waveform. Finally, pump-intensity dependence of emission is presented for three crystal lengths, showing the effects of near-infrared nonlinear optical absorption and THz free-carrier absorption. Measurements, modeling, and calculation of characteristic lengths provide insight into the upper limit of pulse intensity and crystal length for generation of intense terahertz pulses without detriment to the bandwidth. Direct comparison of generation efficiency from GaP and ZnGeP2 is also measured for reference

Measurement of electron density and temperature in plasmas

Application of two laser wavelengths passing through plasma measures electron density and temperature. Function depends on determining absorption of light at two wavelengths. Nature of reaction is explained and schematic diagram of equipment is included

Large-angle scattering and quasi-elastic barrier distributions

We study in detail the barrier distributions extracted from large-angle quasi-elastic scattering of heavy ions at energies near the Coulomb barrier. Using a closed-form expression for scattering from a single barrier, we compare the quasi-elastic barrier distribution with the corresponding test function for fusion. We examine the isocentrifugal approximation in coupled-channels calculations of quasi-elastic scattering and find that for backward angles, it works well, justifying the concept of a barrier distribution for scattering processes. This method offers an interesting tool for investigating unstable nuclei. We illustrate this for the $^{32}$Mg + $^{208}$Pb reaction, where the quadrupole collectivity of the neutron-rich $^{32}$Mg remains to be clarified experimentally.Comment: 26 pages, 10 eps figure

Review of \u3ci\u3eForging New Rights in Western Waters\u3c/i\u3e By Robert G. Dunbar

Dunbar does not address this thorny question. What has resulted is a remarkably useful survey of the flourishing of these new rights in western waters. Students of resource policy as well as water law historians will find this volume crucial to any beginning studies on this complex topic. It offers encouragement and understanding even to the timid who previously had avoided the jungle of water resource law in the West

Phosphorous and Potassium Fertility Management for Maximizing Tart Cherry Fruit Quality and Productivity on Alkaline Soils

Suitable orchard land in regions of high elevation, arid climates, and alkaline soil conditions is becoming more limited due to urban sprawl. With the loss of suitable farmland, increasing input costs, and the lack of sound fertility information for these regions, fruit growers face challenges in producing high quality fruit to meet local and general market demand. The question that arises is whether fruit growers can supply sufficient quantities of quality fruit to take full advantage of local and global demand. Government data for population, fruit production, and fruit consumption in Utah were reviewed to determine the potential size of the local market, and determine whether growers have opportunities to increase production to meet unsatisfied demand for high quality local produce. In addition to market analysis, fertility-based management strategies are needed to optimize yield and fruit quality in production areas of high elevation, arid climates, and alkaline soils. Three different approaches were used to investigate the effect of phosphorus (P) and potassium (K) on tart cherry fruit quality and yield at high elevations, arid climate conditions, and in alkaline soils. The approaches of this study include: a rate-response evaluation using the industry-standard Triple-16 fertilizer (16-16-16), and comparison of P and K fertilizer formulations to determine the most cost effective sources of these nutrients with regard to yield and fruit quality. Additions of P and K maintained adequate yield and fruit quality, but showed no significant difference among treatments, where historically aggressive nutrient management had been practiced. Fertilizer additions did result in a significant increase in yield and fruit quality where nutrient management programs were historically much less aggressive. There is no advantage of higher cost fertilizer formulations over standard low-cost sources (i.e.; Triple-16). Moreover, there is no significant advantage to splitting fertilizer application over time during the growing season. An analysis of government data indicates that, over the past 40 years, Utah has become a net importer of apples (1997), peaches (1987), and sweet cherries (2005), indicating increased local market opportunities. Increasing the fruit supply to the local market can best be accomplished by increasing yields and fruit quality on existing orchard acreage. Optimizing annual P and K nutrient management is an important key to maximizing yield and fruit quality. The results provide foundational guidelines of nutrient management for optimizing tart cherry production and fruit quality under regionally specific conditions

Precambrian Geology in Humboldt Township, Marquette County, Michigan

ABSTRACT-The present study involved investigation of gneissic granite, migmatite, basic dikes, and faults in part of the Southern Complex of Michig.an. The average strike of the foliation of the gneissic granite based upon the orientation of feldspar phenocrysts is N. 60° w·;, the strike of the major dike set is between N. 30° W. and N. 60° W., the average strike of the fault zones-is N. 52° W., and a two-mile long body of migmatite trends about N. 57° W. The known history starts in the early Precambrian, when gneissic granite was emplaced and formed migmatites by incorporation of wall-rock material. Then the rocks were faulted, intruded by dikes, and regionally metamorphosed to the almandine amphibolite facies. After a second period of dike intrusion; hydrothermal solutions that p·assed upward through the fault and dike fissures caused retrograde metamorphism

The In Vitro Bactericidal Activity of Normal and Activated Mouse Macrophages against Salmonella typhimurium C5sr

A comparison of the in vitro bactericidaL activity of normaL and activated macrophages indicated that killing of the viruLent strain of opsonized Salmonella typhimurium C5sr by normaL macrophages was enhanced by the presence of fresh serum in the cuLture medium. In contrast, there was no such requirement for the bactericidaL activity of activated macrophages. The enhanced killing ojfthe bacteria by activated macrophages occurred both in the presence and absence of serum, and this was not accounted for by the existence of macrophagebound immunogLobuLin. The factors in normaL rabbit serum which potentiated the killing of bacteria by normaL macrophages were suspected to be components of the compLement system. Heat-stabLe jactors (immunogLobuLins) in normaL rabbit serum were effective only if they were surface bound immunogLobuLins

Surface drilling technologies for Mars

Rock drilling and coring conceptual designs for the surface activities associated with a manned Mars mission are proposed. Straightforward extensions of equipment and procedures used on Earth are envisioned for the sample coring and shallow high explosive shot holes needed for tunneling and seismic surveying. A novel rocket exhaust jet piercing method is proposed for very rapid drilling of shot holes required for explosive excavation of emergency radiation shelters. Summaries of estimated equipment masses and power requirements are provided, and the indicated rotary coring rigs are scaled from terrestrial equipment and use compressed CO2 from the Martian atmosphere for core bit cooling and cuttings removal. A mass of 120 kg and power of 3 kW(e) are estimated for a 10 m depth capability. A 100 m depth capacity core rig requires about 1150 kg and 32 km(e). The rocket exhaust jet equipment devised for shallow (3m) explosive emplacement shot holes requires no surface power beyond an electrical ignition system, and might have a 15 kg mass