A more informative way to name plutonic rocks — comment by Frost et al.

Published versio

ACEE composite structures technology

Toppics addressed include: advanced composites on Boeing commercial aircraft; composite wing durability; damage tolerance technology development; heavily loaded wing panel design; and pressure containment and damage tolerance in fuselages

An Audible Demonstration Of The Speed Of Sound In Bubbly Liquids

The speed of sound in a bubbly liquid is strongly dependent upon the volume fraction of the gas phase, the bubble size distribution, and the frequency of the acoustic excitation. At sufficiently low frequencies, the speed of sound depends primarily on the gas volume fraction. This effect can be audibly demonstrated using a one-dimensional acoustic waveguide, in which the flow rate of air bubbles injected into a water-filled tube is varied by the user. The normal modes of the waveguide are excited by the sound of the bubbles being injected into the tube. As the flow rate is varied, the speed of sound varies as well, and hence, the resonance frequencies shift. This can be clearly heard through the use of an amplified hydrophone and the user can create aesthetically pleasing and even musical sounds. In addition, the apparatus can be used to verify a simple mathematical model known as Wood's equation that relates the speed of sound of a bubbly liquid to its void fraction. (c) 2008 American Association of Physics Teachers.Mechanical Engineerin

Assessing Population Structure and Genetic Diversity in US Suffolk Sheep to Define a Framework for Genomic Selection

Long-term sustainability of breeds depends on having sufficient genetic diversity for adaptability to change, whether driven by climatic conditions or by priorities in breeding programs. Genetic diversity in Suffolk sheep in the United States was evaluated in four ways: 1) using genetic relationships from pedigree data [(n = 64 310 animals recorded in the US National Sheep Improvement Program (NSIP)]; 2) using molecular data (n = 304 Suffolk genotyped with the OvineHD BeadChip); 3) comparing Australian (n = 109) and Irish (n = 55) Suffolk sheep to those in the United States using molecular data; and 4) assessing genetic relationships (connectedness) among active Suffolk flocks (n = 18) in NSIP. By characterizing genetic diversity, a goal was to define the structure of a reference population for use for genomic selection strategies in this breed. Pedigree-based mean inbreeding level for the most recent year of available data was 5.5%. Ten animals defined 22.8% of the current gene pool. The effective population size (Ne) ranged from 27.5 to 244.2 based on pedigree and was 79.5 based on molecular data. Expected (HE) and observed (HO) heterozygosity were 0.317 and 0.306, respectively. Model-based population structure included 7 subpopulations. From Principal Component Analysis, countries separated into distinct populations. Within the US population, flocks formed genetically disconnected clusters. A decline in genetic diversity over time was observed from both pedigree and genomic-based derived measures with evidence of population substructure as measured by FST. Using these measures of genetic diversity, a framework for establishing a genomic reference population in US Suffolk sheep engaged in NSIP was proposed

Dietary ether lipid incorporation into tissue plasmalogens of humans and rodents

Chronic feeding of 1‐O‐octadecyl‐sn‐glycerol (batyl alcohol) to patients suffering from congenital deficiency in tissue ether glycerolipids showed an increase in the plasmalogens content of their erythrocytes. However, nothing is known about the ether lipid content of other tissues in these patients. Feeding 1‐O‐heptadecyl‐sn‐glycerol to young rats showed that this uncommon ether lipid was incorporated to a high extent into the plasmalogens of all tissues except brain. Comparative studies with other precursors, such as 3‐O‐heptadecyl‐sn‐glycerol, heptadecanol and heptadecanoic acid, indicated a stereospecific incorporation of the dietary 1‐O‐alkyl‐sn‐glycerols into tissue plasmalogens without cleavage of the ether bond. Dietary ether lipids were also shown to be transferred from mothers to suckling rats, but not from pregnant rats to fetuses. The implication of these results to possible dietary ether lipid therapy for patients suffering from peroxisomal disorders is discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141558/1/lipd0401.pd

Assessing the Methodology for Testing Body Armor

with Alyson Wilson, 2010 Joint Statistical Meetings, August 2010

A 30 GHz 5-TeV Linear Collider

We present parameters for a linear collider with a $3$ to $5$ TeV center-of-mass energy that utilizes conventional rf technology operating at a frequency around 30 GHz. We discuss the scaling laws and assumed limitations that lead to the parameters described and we compare the merits and liabilities of different technological options including rf power source, accelerator structure, and final focus system design. Finally, we outline the components of the collider while specifying the required alignment and construction tolerances

Method to provide meta-stable operation of DC microgrid comprising a pulsed load

A Hamiltonian surface shaping power flow control (HSSPFC) method is used to analyze the meta-stability and adjust pulsed power loads on a DC electric power distribution network. Pulsed power loads are nonlinear, time-variant systems that cause nonlinear limit-cycles. During the on periods of a pulsed load, the system can be in an unstable state and is damped back to stability during the off state of the load. Therefore, over the entire period of the pulse the system may only be assessed as meta-stable. As shown through simulation, HIL and hardware results, the HSSPFC method is more accurate than the other small-signal approaches, such as Eigenvalues, Nyquist, and Floquet theory, and can reveal important details about the transient responses and performance.https://digitalcommons.mtu.edu/patents/1141/thumbnail.jp

Adaptação e validação para o espanhol do Inventário Multidimensional de Flexibilidade Psicológica (MPFI): evidências de validade interna e invariância fatorial

This study aims to assess the psychometric properties and internal consistency of the Spanish version of the Multidimensional Psychological Flexibility Inventory (MPFI) within a general population of Argentina. A total of 866 participants with ages between 18 and 84 years (M = 47.33; SD = 17.26) and of both sexes (Men = 40.9%; Women = 59.1%) participated in the main study. A 2-factor higher order model resulted in acceptable fit indices (NFI = .97; NNFI = .98; CFI = .98; IFI = .98; RMSEA .41). The Spanish MPFI also demonstrated both weak (metric) and strong (scalar) factor invariance when compared to the English MPFI given to a United States sample (N = 1630; 18 to 85 years old, M = 50.1, SD = 18.7; 77.0% identifying as women; 86.6% White). Results indicated an acceptable internal consistency in all factors (ω >.74). The adaptation into Spanish of the MPFI presents 60 and 24 items similar to those proposed by the original authors and adequate psychometric properties in the study sample. Regarding its limitations, it should be noted that results only report the factor structure -factor validity- and the internal consistency -reliability- of the MPFI, which is only a first exploratory approach in adapting the scale to the local context. For this reason, future research should continue to explore the psychometric properties of the MPFI in Argentina.Este estudio tiene como objetivo evaluar las propiedades psicométricas y la consistencia interna de la versión en español del Inventario de Flexibilidad Psicológica Multidimensional (MPFI) en población general de Argentina. En el estudio principal participaron un total de 866 participantes con edades entre 18 y 84 años (M = 47,33; DT = 17,26) y de ambos sexos (Hombres = 40,9%; Mujeres = 59,1%). Un modelo de orden superior de 2 factores resultó en índices de ajuste aceptables (NFI = .97; NNFI = .98; CFI = .98; IFI = .98; RMSEA .41). El MPFI español también demostró una invariancia factorial tanto débil (métrica) como fuerte (escalar) en comparación con el MPFI inglés proporcionado a una muestra de los Estados Unidos (N = 1630; 18 a 85 años, M = 50,1, SD = 18,7; 77,0 %). identificándose como mujeres; 86,6% blancos). Los resultados indicaron una consistencia interna aceptable en todos los factores (ω >.74). La adaptación al español del MPFI presenta 60 y 24 ítems similares a los propuestos por los autores originales y adecuadas propiedades psicométricas en la muestra de estudio. En cuanto a sus limitaciones, cabe señalar que los resultados solo reportan la estructura factorial -validez factorial- y la consistencia interna -confiabilidad- del MPFI, lo cual es solo una primera aproximación exploratoria en la adaptación de la escala al contexto local. Por esta razón, futuras investigaciones deben continuar explorando las propiedades psicométricas del MPFI en Argentina.Este estudo tem como objetivo avaliar as propriedades psicométricas e a consistência interna da versão em espanhol do Inventário Multidimensional de Flexibilidade Psicológica (MPFI) em uma população geral da Argentina. Um total de 866 participantes com idades entre 18 e 84 anos (M = 47,33; DP = 17,26) e de ambos os sexos (homens = 40,9%; mulheres = 59,1%) participaram do estudo principal. Um modelo de ordem superior de 2 fatores resultou em índices de ajuste aceitáveis (NFI = 0,97; NNFI = 0,98; CFI = 0,98; IFI = 0,98; RMSEA 0,41). O MPFI espanhol também demonstrou invariância fatorial fraca (métrica) e forte (escalar) quando comparado ao MPFI inglês dado a uma amostra dos Estados Unidos (N = 1630; 18 a 85 anos, M = 50,1, SD = 18,7; 77,0% identificando-se como mulheres; 86,6% brancas). Os resultados indicaram uma consistência interna aceitável em todos os fatores (ω >.74). A adaptação para o espanhol do MPFI apresenta 60 e 24 itens semelhantes aos propostos pelos autores originais e propriedades psicométricas adequadas na amostra do estudo. Em relação às suas limitações, deve-se notar que os resultados apenas relatam a estrutura fatorial -validade fatorial- e a consistência interna -confiabilidade- do MPFI, o que é apenas uma primeira abordagem exploratória na adaptação da escala ao contexto local. Por esse motivo, pesquisas futuras devem continuar explorando as propriedades psicométricas do MPFI na Argentina.Fil: Simkin, Hugo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad de Buenos Aires; ArgentinaFil: Freiberg Hoffmann, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad de Buenos Aires; ArgentinaFil: Caselli, Gabriela. Universidad Nacional de La Matanza; ArgentinaFil: Prozzillo, Paola Alejandra. Universidad de Flores; ArgentinaFil: Rogge, Ronald D.. University Of Rochester; Estados UnidosFil: Wilson, Kelly G.. University of Mississippi; Estados Unido

SLAC/CERN high gradient tests on an X-band accelerating section

High frequency linear collider schemes envisage the use of rather high accelerating gradients: 50 to 100 MV/m for X-band and 80 MV/m for CLIC. Because these gradients are well above those commonly used in accelerators, high gradient studies of high frequency structures have been initiated and test facilities have been constructed at KEK [1], SLAC [2] and CERN [3]. The studies seek to demonstrate that the above mentioned gradients are both achievable and practical. There is no well-defined criterion for the maximum acceptable level of dark current but it must be low enough not to generate unacceptable transverse wakefields, disturb beam position monitor readings or cause RF power losses. Because there are of the order of 10,000 accelerating sections in a high frequency linear collider, the conditioning process should not be too long or difficult. The test facilities have been instrumented to allow investigation of field emission and RF breakdown mechanisms. With an understanding of these effects, the high gradient performance of accelerating sections may be improved through modifications in geometry, fabrication methods and surface finish. These high gradient test facilities also allow the ultimate performance of high frequency/short pulse length accelerating structures to be probed. This report describes the high gradient test at SLAC of an X-band accelerating section built at CERN using technology developed for CLIC