3,472 research outputs found
Fixture facilitates helium leak testing of pipe welds
Fixture facilitates inspection testing of circumferential pipe welds for vacuum tightness, using helium gas as a leakage tracer in conjunction with a mass spectrometer. It consists of a split rubber torus and a mating clamping ring with a vacuum hose fitting
Uncertainty Orientation And Achievement-related Motives As Determinants Of The Motivational Impact Of Self-discrepancies
It has been found that the arousal of achievement-related motives is maximized in situations that involve resolving uncertainty for uncertainty-oriented people, and in situations that do not involve uncertainty resolution for certainty-oriented people (see Sorrentino & Short, 1986). Higgins, Strauman, and Klein (1986) proposed that discrepancies between the way we perceive ourselves and abstract representations of what we could be like, or should be like, may determine motivation because of the resulting affect; they suggested that ideal/own discrepancies lead to feelings of dissatisfaction and increased performance, whereas ought/other discrepancies result in anxiety and poorer performance. Self-discrepancies may also involve uncertainty, however, because they leave us uncertain as to whether we are capable of reaching a self-standard. The principal prediction, therefore, was that success-oriented people would outperform failure-threatened people to a greater extent (reflecting the arousal of achievement-related motives) when there is a perceived self-discrepancy for uncertainty-oriented people, and when there is little or no perceived self-discrepancy for certainty-oriented people. Two studies were conducted to test these predictions. The first was a field study in which students\u27 self-discrepancies regarding performance in a university course were examined in relation to their subsequent performance in that course. The second study involved an experimental manipulation of whether or not subjects experienced self-discrepancies. Feedback from an initial task was varied such that it either indicated that subjects had, or that they had not lived up to their standard, immediately before performing a second task. Results for both studies supported the primary hypothesis; the predicted interaction was found in Study 1 when analysing for ought/other discrepancies (but not when analysing for ideal/own discrepancies), and was also found in Study 2. The proposals by Higgins et al. (1986) regarding the different motivational impact of ideal/own and ought/other discrepancies received partial support in Study 1 only. Results for these studies demonstrate the importance of uncertainty orientation, in interaction with achievement-related motives, in determining the implications of self-discrepancies for achievement. Implications for both the theory of uncertainty orientation, and self-discrepancy theory, are discussed
The Pion-Photon Transition Form Factor and New Physics in the Tau Sector
Recent measurement of the form factor of the neutral pion
in the high region disagrees with {\em a priori} predictions of QCD-based
calculations. We comment on existing explanations, and analyze a possibility
that this discrepancy is not due to poorly understood QCD effects, but is a
result of some new physics beyond the standard model (SM). We show that such
physics would necessarily involve a new neutral light state with mass close to
the mass of , and with stronger than couplings to heavier SM
flavors such as , , and . It is found that only the coupling to the
lepton can survive the existing constraints and lead to the observed
rise of the pion form factor relative to at high . We perform
numerical fits to data and determine the allowed range of masses and couplings
for such new particles. This range of masses and couplings could also reduce or
eliminate the tension between the and decay determinations of
the hadronic vacuum polarization. Dedicated experimental analysis of
pair production in association with such new states should provide a conclusive
test of the new physics hypothesis as an explanation to the pion form factor
rise. We also comment on the calculations of the pion form factor in the chiral
quark model, and point out a possible dynamical origin of the quark mass scale
inferred from the form factor measurement.Comment: 13 pages, 6 figures, revtex4-1; v2: additional references, improved
discussion of pion mixing case, published versio
An explicit upper bound for the Helfgott delta in SL(2, p)
Helfgott proved that there exists a δ > 0 such that if S is a symmetric generating subset of SL(2, p)containing 1 then either S^3=SL(2, p)or |S^3| ≥|S|^1+ δ. It is known that δ ≥ 1/3024. Here we show that δ ≤ (log_2 (7) −1)/6 ≈ 0.3012and we present evidence suggesting that this might be the true value of δ.This is the in press, corrected proof version of the article published by Elsevier in the Journal of Algebra online here: http://www.sciencedirect.com/science/article/pii/S0021869314004888. It will be replaced by the final published version when it becomes available
FIELD STUDY OF AN ENHANCEMENT EFFECT ON LETTUCE SEEDS: Working In Adverse Conditions
During the years 2000-2002, research on organic farms looked at the effect of a healer on lenuce seeds. The basic hypotheses were that the healer would enhance the seeds to produce greater yield and greater health. The first yearl found a significant result for the second hypmhesis, as measured by looking at the fungal damage. The second yea? found significant results on all the measures, greater yield, less fungal damage and less slug damage. However, doing field trials has many problems compared with doing laboratory research, weather being one of the major variables that cannot be controlled. For various reasons, in 2001 trials 6 and 7 were not planted om umil long after they had become pot-bound. The delay in plaming out was so great for trial 6 that the plants never grew properly, and trial 7 was harvested first as those plants grew to a point where they became big enough for sale. In 2002 the research rook place on another farm and was a disaster. For various reasons up to half of the lettuce plants died in the seedling trays, and the people working on the farm became "spooked." They considered that the reason for the loss of plants was due to the research trials upsetting the delicate balance of energy needed to keep the farm running smoothly. Therefore the research was terminated after only two trials were harvested. However, in both 2001 and 2002 significant results were still found. Trials 6 & 7 in 2001 both showed first place "hits" for gross weight of lettuces in the "enhanced" (HX) condition, which, when combined with trials 1 -5, give an average rank for gross weight of 1.92. The net weight was also significanc. When each harvest is ranked, by group, on the number of lettuces produced, the HX group has mean rank of 1.79, with t(11) = -2.75, and two-tailed p 0.019. The total yield was also significant for the HX group. The two trials in 2002 yielded nine experimental vs. comrol pairings. The nine "experiments" comparing net weight HX to another condition yield an average effect size (r) of 0.21 (sd = 0.31), which is statistically significantly greater than chance expectation. The six control experimems (NH v. controls) yield average effect size r = -0.02 (sd = .26), which is not significantly different from zero. These results suggest that a psychic healer can have a practical value for the commercial farmer. This is good news for organic farming where the lack of fungicide, pesticide and artificial fertilizer can result in a lower yield
An Archaeological Investigation of Late Archaic Cerros de TrincherasSites in Chihuahua, Mexico
Cerro Juanaqueña is a large cerro de trincheras located in northwestern Chihuahua, in the municipio of Janos. The site was built over 3000 years ago on the summit and slopes of a 140 meter high basalt hill which overlooks the floodplain of the Rio Casas Grandes and its major tributary, the Rio San Pedro. Large constructed terraces cover an area of about 8 hectares, with over 8 kilometers of terrace wall and 108 stone circles. This informe summarizes the investigations undertaken at Cerro Juanaqueña and other related sites under the oficio No. C.A. 401–36/560 (22 de mayo de 1998) authorized by the Consejo de AntropologÃa. The project was funded in 1997 by National Science Foundation (NSF) SBR-97086210 and in 1998 by NSF SBR-9809839
Tau and muon pair production cross-sections in electron-positron annihilations at sqrt{s} = 10.58 GeV
The calculational precision of \ee\to\tautau and \ee\to\mumu production
cross-sections in electron-positron annihilations at \roots = 10.58 \gev are
studied for the \kk Monte Carlo simulation program. We determine
\sigma(\ee\to\tautau) = (0.919 \pm 0.003) \nb and \sigma(\ee\to\mumu) =
(1.147 \pm 0.005) \nb, where the error represents the precision of the
calculation.Comment: 7 pages, 3 tables, 1 figure (published in Physical Review D 77,
054012 (2008)
Hand-operated plug insertion valve
Hand-operated plug insertion valve seals an evacuated insulation system for upper stage liquid hydrogen tanks on the launch pad. It is light in weight, demountable, and permits evacuation of the system plus sealing after evacuation
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