Striking characteristics of the magnetron ionization gage in helium from 1.9 times 10 to the minus 7 torr to 7 times 10 to the minus 10 torr

Striking characteristics of magnetron ionization gages in helium over low pressure rang

In situ mass analysis of particles by surface ionization mass spectrometry

A qualitative study of the application of surface ionization and mass spectrometry to the in situ detection and constituent analysis of atmospheric particles was conducted. The technique consists of mass analysis of ions formed as a result of impingement of a stream of particles on a hot filament where, it is presumed, surface ionization takes place. Laboratory air particles containing K, Ca, and possibly hydrocarbons were detected. Other known particles such as Al2O3, Pb(NO3)2, and Cr2O3 were analyzed by detecting the respective metal atoms making up the particles. In some cases, mass numbers indicative of compounds making up the particles were detected showing surface ionization of particles sometimes leads to chemical analysis as well as to elemental analysis. Individual particles were detected, and it was shown that the technique is sensitive to Al2O3 particles with a mass of a few nanograms

Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution of the Hawaiian plume

We measured He, Sr, Nd, Pb, and Os isotope ratios and major and trace element concentrations in stratigraphically and paleomagnetically controlled shield-stage lavas from Kauai, Hawaii. The range of 3He/4He ratios (17–28 RA) from Kauai is similar to that reported from Loihi and thus challenges the prevailing notion that high 3He/4He ratios are restricted to the preshield stage of Hawaiian magmatism. 3He/4He ratios vary erratically with stratigraphic position, and chronostratigraphic control from paleomagnetic data indicates very rapid changes in the 3He/4He ratios (up to 8 RA in ~102 years). These variations in helium isotopic ratios are correlated with variations in radiogenic isotope ratios, suggesting rapid changes in melt composition supplying the magma reservoir. A three-component mixing model, previously proposed for Hawaiian shield lavas, does not adequately explain the isotopic data in Kauai shield lavas. The addition of a depleted-mantle (DM) component with the isotopic characteristics similar to posterosional basalts explains the isotopic variability in Kauai shield lavas. The DM component is most apparent in lavas from the Kauai shield and is present in varying proportion in other Hawaiian shield volcanoes. Shield lavas from Kauai sample a high 3He/4He end-member (Loihi component), but while lavas from western Kauai have a larger contribution from the Kea component (high 206Pb/204Pb, anomalously low 207Pb/204Pb relative to 206Pb/204Pb), lavas from eastern Kauai have a larger proportion of an enriched (Koolau) component. The systematic isotopic differences between eastern and western Kauai reflect a gradual migration of the locus of volcanism from west to east, or alternatively east and west Kauai are two distinct shield volcanoes. In the latter case, the two shield volcanoes have maintained distinct magma supply sources and plumbing systems. Our new geochemical data from Kauai are consistent with the existence of a single high 3He/4He reservoir in the Hawaiian plume and suggest that the proportion of the different mantle components in the plume have changed significantly in the past 5 Myr. The long-term evolution of the Hawaiian plume and the temporal variability recorded in Kauai lavas require more complex geochemical heterogeneities than suggested by radially zoned plume models. These complexities may arise from heterogeneities in the thermal boundary layer and through variable entrainment of ambient mantle by the upwelling plume

Plume dispersion of the exhaust from a cryogenic wind tunnel

An analytical model was developed to predict the behavior of the plume exhausting from the cryogenic National Transonic Facility. Temperature, visibility, oxygen concentration, and flow characteristics of the plume are calculated for distance downwind of the stack exhaust. Negative buoyancy of the cold plume is included in the analysis. Compared to photographic observations, the model predicts the centerline trajectory of the plume fairly accurately, but underpredicts the extent of fogging. The diffusion coefficient is revised to bring the model into better agreement with observations

Sensory neuron differentiation is regulated by Notch signaling in the trigeminal placode

AbstractTrigeminal sensory neurons develop from the neural crest and neurogenic placodes, and have been studied as a principal model of sensory neuron formation. While the Notch pathway has been extensively characterized in central nervous system development and other developmental processes, it has not been well characterized in sensory neurogenesis. Here we studied the functional role of Notch signaling in the trigeminal ophthalmic (opV) placode, a prime model of sensory neurogenesis. To establish a good spatiotemporal description of Notch pathway genes in the chick trigeminal placode, a stage-specific expression analysis was conducted, showing that expression of most Notch pathway genes and effectors are expressed in the placode, with expression primarily being confined to ectodermal cells. Expression was highest at stages of peak neuronal differentiation. To test the function of Notch signaling in opV placode cell differentiation, Notch receptor cleavage was blocked using the gamma-secretase inhibitor, DAPT, or signaling was activated by misexpression of the Notch intracellular domain (NICD). Notch activation resulted in a significant reduction in sensory neurogenesis. Cells remained in the ectoderm and did not differentiate. Expression of the opV specification marker Pax3 was also lost in targeted cells. DAPT exposure resulted in a dramatic increase in neurogenesis without increasing proliferation, where many differentiated cells were found in the mesenchyme and, surprisingly, within the ectoderm. This is the first result clearly showing prolific neuronal differentiation in the ectoderm of the trigeminal placodes after experimental manipulation of a molecular signaling pathway, thus identifying Notch signaling as a primary regulator of the sensory neuron fate in the opV placode

Damping Mechanisms for Microgravity Vibration Isolation (MSFC Center Director's Discretionary Fund Final Report, Project No. 94-07)

As a research facility for microgravity science, the International Space Station (ISS) will be used for numerous investigations such as protein crystal growth, combustion, and fluid mechanics experiments which require a quiescent acceleration environment across a broad spectrum of frequencies. These experiments are most sensitive to low-frequency accelerations and can tolerate much higher accelerations at higher frequency. However, the anticipated acceleration environment on ISS significantly exceeds the required acceleration level. The ubiquity and difficulty in characterization of the disturbance sources precludes source isolation, requiring vibration isolation to attenuate the anticipated disturbances to an acceptable level. This memorandum reports the results of research in active control methods for microgravity vibration isolation

Ranking Objections to Christian Theism: A Survey of Subjective Declarations and their Correlations with Expert Opinions

There have been numerous books written on the top objections to Christianity—sometimes stated as “common,” “major,” “frequent,” “every day,” “cultural,” “tough,” “difficult” objections. However, there is a dearth of behavioral studies in the literature that show how and given population ranks objections to Christianity. As such, the apologist has had to rely on expert opinions from the books that have been authored. These expert opinions are based on familiarity with the literature in the field and contact with laity from university, church, and other speaking engagements. The purpose of this study is to document trends in how people report the relative strength of objections to Christian theism.[1] We analyze whether these trends correlate with popular works of Christian apologists—our baseline for expert opinion. Further, we determine whether there are any statistically significant relationships between reported demographics, rankings, and attitudes. Summary of Results and Analysis. Subjective declarations of respondents of the questionnaire showed that most participants were either 18-24 (marginally more than 55-64 and 65-74), male (marginally more than female), had some college (marginally more than bachelor’s, master’s degrees), lived in a suburban community, or lived in the South. In comparing the expert opinion baseline with the aggregate survey ranking results, we see similar rankings between the objection that “God is unloving/immoral” and that the “Bible is not inerrant” (ranked by both as 1st and 2nd, respectively) at the higher end of the spectrum. We found that those identified as agnostic seem to have the closest potential correlation to expert opinion (baseline). The mean of their rankings produced four objections that closely approximated the baseline, one objection that was about one rank removed from the baseline, and three objections that were about two ranks from the baseline. For demographics and rankings, we found statistically significant relationships between religious identification and the objection “God does not exist” with those who identified as atheists, giving it an average ranking of 3.74 (on a scale of 1-13; 1 = highest, 13 = lowest). For demographics and attitudes, we found statistically significant relationships between religious identification and age, religious discussion importance, and attitude toward Christian theism. (See “Analysis” section.) [1] The study was done under the School of Divinity Department at Liberty University in compliance with Liberty University’s Internal Review Board (Research Ethics Office). IRB-FY21-22-12. Policy: Post-2018 Rule. Submitted 07-06-2021. Last approved 09-07-2021, no expiration date applicable

Evaluational adjectives

This paper demarcates a theoretically interesting class of "evaluational adjectives." This class includes predicates expressing various kinds of normative and epistemic evaluation, such as predicates of personal taste, aesthetic adjectives, moral adjectives, and epistemic adjectives, among others. Evaluational adjectives are distinguished, empirically, in exhibiting phenomena such as discourse-oriented use, felicitous embedding under the attitude verb `find', and sorites-susceptibility in the comparative form. A unified degree-based semantics is developed: What distinguishes evaluational adjectives, semantically, is that they denote context-dependent measure functions ("evaluational perspectives")—context-dependent mappings to degrees of taste, beauty, probability, etc., depending on the adjective. This perspective-sensitivity characterizing the class of evaluational adjectives cannot be assimilated to vagueness, sensitivity to an experiencer argument, or multidimensionality; and it cannot be demarcated in terms of pretheoretic notions of subjectivity, common in the literature. I propose that certain diagnostics for "subjective" expressions be analyzed instead in terms of a precisely specified kind of discourse-oriented use of context-sensitive language. I close by applying the account to `find x PRED' ascriptions

Discrete multivortex solitons

We introduce discrete multivortex solitons in a ring of nonlinear oscillators coupled to a central site. Regular clusters of discrete vortices appear as a result of mode collisions and we show that their stability is determined by global symmetries rather than the stability of constituent vortices. Stable multivortex solitons support complex vortex dynamics including charge flipping and spiraling.Comment: 3 pages, 3 figure