Mars-Earth transfer time of lherzolite Yamato-793605

We determined the cosmic-ray exposure age of Yamato-793605 based on cosmic-ray produced ^3He, ^Ne, and ^Ar. The average age is 4.4±1.0 Ma and agrees with the exposure ages of the two other martian lherzolites ALH77005 and LEW88516. The similarity in petrology, chemistry, oxygen isotopic composition, and cosmic-ray exposure history shows that the three lherzolitic martian meteorites originate from the same parent magma and were ejected from Mars by the same ejection event. The basaltic shergottites EET79001,QUE94201,Shergotty, and Zagami strongly differ from the three lherzolites in mineralogical and chemical composition and were ejected by events that occurred 1 Ma and 3 Ma (EET79001) later than that responsible for the delivery of the lherzolites. We propose that these differences are sufficiently important to merit distinct meteorite classification and to name ALH77005,LEW88516,and Y-793605 "lherzolites", in contrast to the "shergottites" EET79001,QUE94201,Shergotty, and Zagami

Mars ejection times and neutron capture effects of the nakhlites Y000593 and Y000749, the olivine-phyric shergottite Y980459, and the lherzolite NWA1950

We measured the concentrations and isotopic composition of the noble gases He, Ne, Ar, Kr, and Xe in the paired antarctic nakhlites Y000593 and Y000749, and in the antarctic olivine-phyric shergottite Y980459. Furthermore, we analyzed He, Ne, and Ar in lherzolite NWA1950. For the two nakhlite specimens we obtain Mars ejection times of 11.2±1.2Ma and 12.3±1.8Ma, respectively, in agreement with those for the four nakhlites dated before. Y980459 yields longer cosmic-ray exposure (CRE) ages based on ^(21)Ne and ^(38)Ar (2.9 and 2.5Ma, respectively) than based on ^3He, ^(81)Kr-^(83)Kr, and ^(10)Be (1.5, 1.9, and 1.1Ma, respectively).We interpret this difference to be due to an additional cosmogenic component produced by solar cosmic rays. The Mars ejection time of this meteorite is essentially its CRE age of 1.1Ma and agrees with the ejection times of the four other olivine-phyric shergottites. The ejection time of NWA1950 is 4.1±1.4Ma and lies within the range of the other three lherzolites. In the two nakhlites and in Y980459 we observe effects induced by the reaction ^(79)Br (n, γβ) ^(80)Kr. For the nakhlites this ^(80)Kr was produced in free space during Mars-Earth transfer; from its concentration we calculate a pre-atmospheric mass of >170kg. On the other hand, a pre-atmospheric size for the Y980459 meteoroid can not be derived from our data. We interpret the occurrence of an excess of ^(80)Kr_n to be due to trapping of this nuclide from the martian atmosphere, as was observed by other workers for martian meteorite EETA79001. For Y980459 we also find an excess of 71×10^(-8)cm^3STP ^(40)Ar/g that originates from trapped martian atmospheric gases. We show that up to eight impact events in a time span of 0.73Ma to 19.8Ma are responsible for ejecting the martian meteorites studied until now. Each event occurred in a specific surface region characterized by the mineralogy of the meteorites blasted off by these cratering processes

Noble gases, chemical composition, and cosmic-ray exposure age of the Yamato-74357 lodranite

Cosmic-ray produced ^3He, ^Ne, and ^Ar concentrations and the chemical composition of the Yamato-74357 lodranite have been determined. Concordant concentrations of ^3He and ^Ne have been obtained on both samples (Bern and Misasa). The concentration of cosmogenic ^Ar is twice as high in the Bern as in the Misasa sample. The ^3He, ^Ne and ^Ar data for both samples yield an average cosmic-ray exposure age of 5.8±2.0Ma. This age indicates that Yamato-74357 belongs to the lodranite group, which probably originates from a common break-up event about 5Ma ago. Radiogenic ^4He and ^Ar concentrations in the Bern sample are higher than those in the Misasa sample by more than a factor of two, suggesting that minerals enriched in U, Th and K are enriched in the finer grained fraction. The isotopic compositions of Kr and Xe are identical to those of the terrestrial atmosphere, except for the ^Xe abundance. The small ^Xe excess (^Xe/^Xe=1.15±0.04) is presumably due to the early formation of this meteorite

Preliminary report on the Yamato-86032 lunar meteorite: III. Ages, noble gas isotopes, oxygen isotopes and chemical abundances

The isotope abundances of He, Ne, Ar, Kr, and Xe, including ^Kr, the oxygen isotopic composition, and the concentrations of Na, K, Sc, Ti, Cr, Fe, Co, Y, Zr, La, Sm, Eu, Hf, Ta, and W were determined for the lunar meteorite Yamato-86032. Based on the radionuclide ^Kr we obtain a terrestrial age of 72000±30000 years, whereas the cosmic-ray exposure age is 10.6±0.6 Ma assuming exposure of the meteorite as a small object in space. Exposure to cosmic rays occurred at shallow shielding of about 40g/cm^2. The K-Ar gas retention ages of two separate splits are 3680±300 Ma and 3810±400 Ma, respectively. All ages agree with those for the lunar meteorites Y-82192 and Y-82193 recovered in the same area on the antarctic ice. The small amounts of trapped solar wind noble gases indicate that the Y-86032 material was exposed only briefly, some grains perhaps not at all, to the solar wind. The concentrations are similar to those of the Yamato-82 lunar meteorites. The oxygen isotopic composition is within the range of that for lunar rocks. The chemical composition of the samples from Y-86032,Y-82192,and Y-82193 is uniform for most major elements but not for all minor and trace elements, probably due to inhomogeneity of the source material. From the fact that the history of Y-86032 is the same as that of Y-82192/3 we conclude that these three rocks are pieces of the same meteorite fall

Helium, uranium and thorium analyses of ancient and modern gold objects: estimates of their time of manufacturing

Authenticating archaeological gold objects is a major problem, as gold is probably the most difficult material in terms of detecting modern forgeries. In 1996 we published the results of the study of faked and genuine gold crystals from the Santa Elena gold mine in Venezuela, and demonstrated that the U/Th – He dating method is a powerful tool for detecting forgeries among gold objects. U and Th decay by emitting He atoms that remain stored in gold. By measuring U, Th, and He, the time when the He trapping process started can be determined. In the 1996 publication we also mentioned that the same method can be applied to ancient gold objects, in order to determine the time when they experienced their last melting process and, thus, to verify their antiquity. In the present work we report on a systematic and quantitative study of He, U, and Th in a large number of ancient and modern gold objects.L’authentification d’objets en or est un problème majeur, car l’or est probablement le matériau le plus difficile quand il s’agit de détecter des contrefaçons modernes. En 1996 nous avons publié les résultats d’une étude de cristaux d’or faux et authentiques de la mine d’or de Santa Elena, au Venezuela, et nous avons montré que la méthode de datation U/Th – He est un outil puissant pour détecter les contrefaçons dans le cas des objets en or. La décroissance de l’U et du Th se fait par émission d’atomes d’He qui restent stockés dans l’or. La mesure de l’U, du Th et de l’He permet de déterminer le moment de départ du processus de piège de l’He. Dans notre publication de 1996, nous avons aussi mentionné  que cette même technique peut être appliquée aux objets d’or anciens, de façon à déterminer le moment correspondant à leur dernière fonte et ainsi de vérifier leur ancienneté. Dans cet article nous présentons une étude systématique et quantitative de l’He, de l’U et du Th dans un large nombre d’objets d’or anciens et modernes

The Villalbeto de la Peña meteorite fall: I. Fireball energy, meteorite recovery, strewn field, and petrography

An impressive daylight fireball was observed from Spain, Portugal, and the south of France at 16h46m45s UTC on January 4, 2004. The meteoroid penetrated into the atmosphere, generating shock waves that reached the ground and produced audible booms. The associated airwave was recorded at a seismic station located 90 km north of the fireball trajectory in Spain, and at an infrasound station in France located 750 km north-east of the fireball. The absolute magnitude of the bolide has been determined to be -18 ± 1 from a casual video record. The energy released in the atmosphere determined from photometric, seismic, and infrasound data was about 0.02 kilotons (kt). A massive fragmentation occurred at a height of 28 ± 0.2 km, resulting in a meteorite strewn field of 20 ± 6 km. The first meteorite specimen was found on January 11, 2004, near the village of Villalbeto de la Pena, in northern Palencia (Spain). To date, about 4.6 kg of meteorite mass have been recovered during several recovery campaigns. The meteorite is a moderately shocked (S4) L6 ordinary chondrite with a cosmic-ray-exposure age of 48 ± 5 Ma. Radioisotope analysis shows that the original body had a mass of 760 ± 150 kg, which is in agreement with the estimated mass obtained from photometric and seismic measurements

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI