A new measurement of the decay rate of the negative positronium ion:status and preliminary results

2005 ◽  
Vol 83 (4) ◽  
pp. 413-423 ◽  
Author(s):  
F Fleischer ◽  
K Degreif ◽  
G Gwinner ◽  
M Lestinsky ◽  
V Liechtenstein ◽  
...  
Keyword(s):  
Experimental Data ◽  
Decay Rate ◽  
Lifetime Measurement ◽  
The Other ◽  
Body System ◽  
Positron Source ◽  
Preliminary Results ◽  
The Status ◽  
Set Up ◽  
Three Body

A great number of theoretical papers have been published dealing with the negative positronium ion Ps–. On the other hand, experimental data on this purely leptonic three-body system (e+e–e–) is very limited. Apart from a first observation, a lifetime measurement with an accuracy of 4% has been published. We have built a set-up to produce Ps– making use of moderated positrons from a 22Na source, and we are presently running an experiment to improve on its decay rate. This paper discusses the status of the project as well as the possibilities of extending these investigations to other properties of Ps–, the latter becoming possible using the NEPOMUC positron source at the FRM II reactor in Munich.PACS No.: 36.10.Dr

Extended Camus Theory and Higher Order Conjugated Curves

2019 ◽  
Author(s):  
Cody Leeheng Chan ◽  
Kwun-Lon Ting
Keyword(s):  
Stationary Point ◽  
Higher Order ◽  
The Body ◽  
The Other ◽  
Body System ◽  
Straight Line ◽  
Pair Generation ◽  
Curvature Theory ◽  
Three Body ◽  
Two Bodies

Abstract According to Camus’ theorem, for a single DOF 3-body system with the three instant centers staying coincident, a point embedded on a body traces a pair of conjugated curves on the other two bodies. This paper discusses a fundamental issue not addressed in Camus’ theorem in the context of higher order curvature theory. Following the Aronhold-Kennedy theorem, in a single degree-of-freedom three-body system, the three instant centers must lie on a straight line. This paper proposes that if the line of the three instant centers is stationary (i.e. slide along itself), on the line of the instant centers a point embedded on a body traces a pair of conjugated curves on the other two bodies. Another case is that if the line of the three instant centers rotate about a stationary point, the stationary point embedded on the body also traces a pair of conjugated curves on the other two bodies. The paper demonstrates the use of instantaneous invariants to synthesize such a three-body system leading to a conjugate curve-pair generation. It is a supplement or extension of the Camus’ theorem. The Camus’ theorem may be regarded as a special singular case, in which all three instant centers are coincident.

The negative ion of positronium: measurement of the decay rate and prospects for further experiments

2007 ◽  
Vol 85 (5) ◽  
pp. 487-495 ◽  
Author(s):  
F Fleischer ◽  
G Gwinner ◽  
C Hugenschmidt ◽  
K Schreckenbach ◽  
P Thirolf ◽  
...  
Keyword(s):  
Decay Rate ◽  
Bound State ◽  
Negative Ion ◽  
Experimental Result ◽  
Three Body Problem ◽  
Positron Source ◽  
Interesting Object ◽  
Three Body ◽  
Beam Foil

The negative positronium (Ps–) ion consisting of two electrons and a positron (e+e–e–), represents the simplest three-body system with a bound state. Its constituents are stable, point-like particles, and it is essentially free from perturbations by strong interaction effects. Together with the rather unique mass ratio, these properties make the positronium ion an interesting object for studying the quantum-mechanical three-body problem. We present a new determination of the decay rate of Ps–, using a beam-foil method and a stripping-based detection technique. The measured value of Γ = 2.089(15) ns–1 is a factor of six times more precise than the previous experimental result, and there is excellent agreement both with the latter and with the theoretical value. With the new high-intensity positron source NEPOMUC at the FRM-II research reactor in Munich being available, a further improvement in precision seems possible. Moreover, the high flux of low-energy positrons at this facility brings other properties of this exotic system within reach of experiments. The prospects for such investigations are discussed.PACS No.: 36.10Dr

The temperature-range of formation for tourmaline, rutile, brookite, and anatase in the Dartmoor granite

1927 ◽  
Vol 21 (116) ◽  
pp. 205-220 ◽  
Author(s):  
A. Brammall ◽  
H. F. Harwood
Keyword(s):  
Experimental Data ◽  
Igneous Rocks ◽  
The Other ◽  
Secondary Minerals ◽  
Temperature Range ◽  
Other Hand ◽  
The Status ◽  
Direct Separation

The range of temperature within which tourmaline can arise in nature has not hitherto been determined. No synthesis of this mineral is on record, and experimental data are therefore lacking. On the other hand, rutile, brookite, and anatase have all been prepared synthetically, and the experimental data suggest their rutile is formed at the highest temperatures, brookite at temperatures considerably lower, and anatase at a point still lower on the scale. It is generally conceded that for rutile a pyrogenic origin is possible, and that brookite and anatase appear only as secondary minerals. The status of tourmaline as a possible pyrogenic mineral is regarded as doubtful by Clarke, who states that' in igneous rocks tourmaline seems to have been produced by fumarole action, and not as a direct separation from the magma'.

Preliminary Exploration of the Dynamic Model and Experiment on an Impact between a Tennis Ball and Racket

2014 ◽  
Vol 494-495 ◽  
pp. 297-300
Author(s):  
Hui Hui Hong ◽  
Liang Han
Keyword(s):  
Experimental Data ◽  
Dynamic Model ◽  
Sports Injuries ◽  
Test System ◽  
Experimental Results ◽  
Tennis Ball ◽  
Preliminary Results ◽  
Preliminary Study ◽  
Set Up ◽  
The Impact

The research on an impact between a tennis ball and racket is very significant to improve the level of tennis and reduce the sports injuries. A preliminary study on an impact between a tennis ball and racket is carried out in this paper. It is composed of four parts: the reference of the existed dynamic model, the experimental set-up, the test system, the collection and analysis of experimental data. The preliminary experimental results are compared with the dynamic model, and the impact dynamic model can be improved after considering every effect on the impact. The preliminary results show that the model can be used to predict the tennis impact on the racket with different inbound velocity.

scholarly journals OCHRONA CZŁONKÓW RODZINY SPADKODAWCY NA TLE HISTORYCZNOPRAWNYM ORAZ PRAWNOPORÓWNAWCZYM

2017 ◽  
Vol 8 (2) ◽  
pp. 149
Author(s):  
Witold Borysiak
Keyword(s):  
Mental Disorder ◽  
Legal System ◽  
Family Members ◽  
The Other ◽  
Roman Law ◽  
General Clause ◽  
The Status ◽  
Statutory Protection ◽  
Set Up ◽  
Do So

Protection of the Deceased’s Family Members in the Historical and Comparative PerspectiveSummaryAll of the contemporary legal systems provide special regulations which protect the deceased’s family members from order’s occurring in his will. Freedom of the testacy is one of the most important rules in the law of successions. Nevertheless it should have limits – the most common example of that situation exists when deceased’s orders omits entirely the members of his closest family.The origins of that protection could be found in the Roman Law. This legal system creates two types of protection – “counter-will formal succession” (previous in the Roman Law evolution) and “counter-will material succession”.According to the first one, testator has a duty to disinherit all of his sons (sui heredes) in the clear and precise words (exhereditatio nominatim). He should also disinherit all of the other members of his family (such as daughters or grandchildren); however he has possibility to do so in a general clause. His will would be overthrown if he has not disinherited members of his family. In that case entitled persons acquired the status of the heirs. This system gave no property rights to descendants of the deceased - they had only right to be an heir or to be disinherit (which was described in the rule that sui heredes should be set up as heirs or should be disinherit - sui heredes aut instituendi sunt aut exheredandi).According to the second type of protection if deceased did not gave part of his property (so called pars legitima) to the entitled persons they have a legal claim (querela inofficiosi testamenti) to declare his will void. On the ground of that regulation existed fiction that testator, who disinherit the members of his closed family, acting in the mental disorder (cum colore insaniae) and violates his father duties (action contra officium pietatis). Roman Law protects the entitled person also against all of the donationes (those performing during the live of testator and mortis causa donations) in which deceased try to evade statutory protection of his family members.

Extended Camus Theory and Higher Order Conjugated Curves

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Cody Leeheng Chan ◽  
Kwun-Lon Ting
Keyword(s):  
Stationary Point ◽  
Higher Order ◽  
Degree Of Freedom ◽  
The Other ◽  
Body System ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Pair Generation ◽  
Three Body ◽  
Two Bodies

According to Camus’ theorem, for a single degree-of-freedom (DOF) three-body system with the three instant centers staying coincident, a point embedded on a body traces a pair of conjugated curves on the other two bodies. This paper discusses a fundamental issue not addressed in Camus’ theorem in the context of higher order curvature theory. Following the Aronhold–Kennedy theorem, in a single degree-of-freedom three-body system, the three instant centers must lie on a straight line. This paper proposes that if the line of the three instant centers is stationary (i.e., slide along itself) on the line of the instant centers, a point embedded on a body traces a pair of conjugated curves on the other two bodies. Another case is that if the line of the three instant centers rotates about a stationary point, the stationary point embedded on a body also traces a pair of conjugated curves on the other two bodies. The paper demonstrates the use of instantaneous invariants to synthesize such a three-body system leading to a conjugate curve-pair generation. It is a supplement or extension of Camus’ theorem. Camus’ theorem may be regarded as a special singular case, in which all three instant centers are coincident.

scholarly journals Preliminary UT0 Results from EROLD Data

1979 ◽  
Vol 82 ◽  
pp. 261-262
Author(s):  
Odile Calame
Keyword(s):  
Computer Software ◽  
The Other ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Preliminary Results ◽  
Station Data ◽  
Single Station ◽  
The Status

The status of the EROLD campaign has already been described in another paper (Mulholland, 1979). Since the beginning of 1977 all of the computer software has been ready to work. With the expectation that at least one other station would be able to operate before the end of 1977, it appeared not very interesting to use the single-station data for the study of UT0 during the last year since the other parameters of the Earth's rotation can be determined only with multiple stations. However, as this situation of a single operating station continues, it seemed to be preferable to attempt some determinations of UT0, even if that represents only a part of the goals envisioned from this campaign. We give here a brief resume of our preliminary results.

COMMITTEE ON NUTRITION

PEDIATRICS ◽  
1960 ◽  
Vol 26 (4) ◽  
pp. 715-721
Keyword(s):  
Experimental Data ◽  
Trace Elements ◽  
The Other ◽  
Other Hand ◽  
Essential Trace Elements ◽  
Set Up

A diet that is well balanced in other respects usually provides adequate amounts of the essential trace elements. Except for iron, iodine, and fluorine there is rarely any need for supplying supplemental amounts of any of these minerals. Many of the known complex interrelations between trace elements are still only partly understood, and others, doubtless, remain to be discovered. Those known relations based on sound experimental data suggest that the use of "shotgun" mineral supplementations in an attempt to supply all the required trace elements, may set up gross imbalances and is obviously contraindicated. On the other hand, milk is a relatively poor source of most trace elements, and there is, therefore, reason to introduce a variety of foods in the baby's life, commencing at about 3 to 4 months of age.

scholarly journals VARIATIONS OF RED COLOR COVERAGE OF CULTURED NEON TETRA (Paracheirodon innesi) FOR BREEDING IMPROVEMENT STRATEGIES

2021 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
Ruby Vidia Kusumah ◽  
Dinar Tri Soelistyowati ◽  
Alimuddin Alimuddin ◽  
Melta Rini Fahmi
Keyword(s):  
Standard Length ◽  
Ornamental Fish ◽  
The Other ◽  
Image Method ◽  
Breeding Strategies ◽  
Fish Farms ◽  
Red Color ◽  
Improvement Strategies ◽  
The Status ◽  
Set Up

Red color coverage (RCC) is a commercial trait developed and refined to improve the appearance of many ornamental fish commodities. In neon tetra, the status of variation of RCC is not yet investigated or reported. This study aimed to analyze the RCC variation of cultured neon tetra as a basis for breeding strategies. A total of 900 neon tetras (standard length, SL, of 2.29 ± 0.16 cm) were collected from Bojongsari, Curug, and Pondok Petir fish farms located in Depok Districts, West Java. All fish were relocated and reared in a fish farm specialized in culturing neon tetra for two weeks using nine aquariums with photoperiod set up of 12 hours bright and 12 hours dark. The RCC traits were determined according to the percentages of RCC length (%LRCC), RCC width (%WRCC), and RCC area (%ARCC) and quantified using the digital image method. The result showed that the RCC varied by sex, size, and original location (P<0.05) in a low coefficient of variation (1.89%-11.41%). The RCC values in the male group were higher than that of females based on %LRCC and %ARCC parameters (P<0.05). Males had the highest %LRCC at size LXL, which was correlated with SL (r 0.25, P<0.1), of females at M size. The %LRCC values of the neon tetra population from the Bojongsari farm were higher than those from the other locations. Based on these findings, breeding strategies of the RCC traits should consider sex, size, and population (farm location) variations. Specifically for neon tetra, this strategy should be based on selecting the SL or %LRCC parameter of M for females and LXL for males.

scholarly journals Study of Approximations for Electron?Atom Direct Reactions

1983 ◽  
Vol 36 (5) ◽  
pp. 665 ◽  
Author(s):  
IE McCarthy ◽  
AT Stelbovics
Keyword(s):  
Experimental Data ◽  
Electron Scattering ◽  
Experimental Error ◽  
Degrees Of Freedom ◽  
Body System ◽  
Many Body ◽  
Coupled Channels ◽  
Direct Reactions ◽  
Many Body Systems ◽  
Three Body

The electron-hydrogen system is a true three-body system which provides an excellent test for theories of reactions in many-body systems that approximately involve only three-body degrees of freedom. The coupled-channels optical approximation reproduces experimental data in most cases within experimental error. The approximation may be extended to a larger space of coupled channels by various approximations which are tested with the example of 54�42 e V electron scattering on the Is, 2s and 2p space for hydrogen, extended by the addition of 3s and 3p channels. Channels outside this five-state space are treated by including the corresponding polarization potentials.

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