The La Luna/Río Negro(.) Petroleum system at the Urdaneta West Field, lake Maracaibo basin, NW Venezuela: ID basin modelling and secondary oil migration

This paper investigates the timing of hydrocarbon generation in the northern part of the Urdaneta West field in the NW of the Lake Maracaibo Basin, NW Venezuela, based on ID basin modelling at three wells referred to as wells X, Y and Z. Kitchen areas were identified and secondary migration directions were inferred based on analyses of the thermal and burial history of the Upper Cretaceous La Luna Formation source rock and the geochemistry of 20 oil samples from the Río Negro Formation reservoir. Aliphatic hydrocarbons in the oil samples were analysed by gas chromatography - mass spectrometry (GC-MS) while the vanadium- nickel and sulphur contents were determined by energy dispersive X-ray spectrometry and inductively coupled plasma optical emission spectroscopy, respectively. Bulk and molecular characterizations indicated that the oils originated from a marine carbonate source rock containing oil-prone Type II kerogen, consistent with generation by the La Luna Formation. Burial and thermal history modelling in the study area indicated that the La Luna source rock at wells X, Y and Z reached the oil window during the late Eocene, mid-Eocene and early Paleocene respectively. ID model results from the three wells showed that hydrocarbon generation began in the early Eocene. The transformation ratio of the La Luna Formation source rock in the modelled wells reached values of 35%, 98% and 100% by the end of the Eocene. In the Urdaneta West field, two different oil charges appear to have mixed in the Río Negro reservoir. Both oil charges were generated by the La Luna Formation source rock but at different times. A first charge of less mature oil occurred in the middle-late Eocene (Phase 1 generation), and a second, more mature oil charge took place in the Miocene - Quaternary (Phase 2 generation). The kitchen area for the first oil charge is inferred to have been located to the north and NE of Urdaneta West; that for the second oil charge to the south of the field. This migration model is supported by observed variations in the geochemical compositions of the oil samples analysed from different wells in the Urdaneta West field.J.G. Diaz acknowledges the support of the PDVSA Western Exploration Project Management and the University of Zulia. The authors are grateful to Iván Chirino and Patricia Marín for their scientific assistance. We are also grateful to the JPG referees (Karla Quintero-Bonilla, Katya Reategui and anonymous) whose comments helped to improve the original version of this manuscript. Carlos Boente obtained a post-doctoral contract within the program PAIDI 2020 (Ref 707 DOC 01097), co-financed by the Junta de Andalucía (Andalusian Government) and the EU

Assessment of metal and metalloid contamination in soils trough compositional data: the old Mortórios uranium mine area, central Portugal

Soils from the old Mortórios uranium mine area were studied to look for contamination, as they are close to two villages, up to 3 km away, and used for agriculture. They are mainly contaminated in U and As and constitute an ecological threat. This study attempts to outline the degree to which soils have been affected by the old mining activities through the computation of significant hot clusters, Traditional geostatistical approaches commonly use raw data (concentrations) accepting that the analyzed elements represent the soil’s entirety. However, in geochemical studies these elements are just a fraction of the total soil composition. Thus, considering compositional data is pivotal. The spatial characterization, considering raw and compositional data together, allowed a broad discussion about not only the concentrations’ spatial distribution, but also a better understanding on the possibility of trends of “relative enrichment” (RE) and, furthermore an insight in U and As fate. The highest proportions (Compositional data) on U (up to 33%), As (up to 35%) and Th (up to 13 %) are reached in the south-southeast segment. However, the highest concentrations (Raw data) occur in north and northwest of the studied area, pointing out to a “relative enrichment” towards the south-southeast zone. The Mondego Sul area is mainly contaminated in U and As, but also in Co, Cu, Pb and Sb. The Mortórios area is less contaminated than the Mondego Sul area.This research was supported by the Fundação para a Ciência e a Tecnologia through projects UID/ GEO/04035/201C and UID/MAR/04292/2013-MARE (PPC). Boente obtained a grant from the ‘‘Formación del Profesorado Universitario’’ program, financed by the ‘‘Ministerio de Educación, Cultura y Deporte de España.’’ M.T.D Albuquerque acknowledges a scholarship 567 SFRH/BSAB/ 127907/2016 from the Foundation for Science and Technology (Portugal)

Search for lepton-flavour-violating decays of Higgs-like bosons.

A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/c2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb-1 . The tau leptons are reconstructed in both leptonic and hadronic decay channels. An upper limit on the production cross-section multiplied by the branching fraction at 95% confidence level is set and ranges from 22 pb for a boson mass of 45 GeV/c2 to 4 pb for a mass of 195 GeV/c2

Observation of an Excited Bc+ State

Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

Angular analysis of B0→D∗−D∗+s with D∗+s→D+sγ decays

The first full angular analysis of the B0→D∗−D∗+s decay is performed using 6 fb−1 of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The D∗+s→D+sγ and D*− → D¯¯¯¯0π− vector meson decays are used with the subsequent D+s → K+K−π+ and D¯¯¯¯0 → K+π− decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be fL = 0.578 ± 0.010 ± 0.011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [ℬ(B0→D∗−D∗+s) × ℬ(D∗+s→D+sγ)]/ℬ(B0 → D*−D+s) is measured to be 2.045 ± 0.022 ± 0.071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed Bs → D*−D+s decay is made with a significance of seven standard deviations. The branching fraction ratio ℬ(Bs → D*−D+s)/ℬ(B0 → D*−D+s) is measured to be 0.049 ± 0.006 ± 0.003 ± 0.002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractionsS

Wavelet penalized likelihood estimation in generalized functional models

The paper deals with generalized functional regression. The aim is to estimate the influence of covariates on observations, drawn from an exponential distribution. The link considered has a semiparametric expression: if we are interested in a functional influence of some covariates, we authorize others to be modeled linearly. We thus consider a generalized partially linear regression model with unknown regression coefficients and an unknown nonparametric function. We present a maximum penalized likelihood procedure to estimate the components of the model introducing penalty based wavelet estimators. Asymptotic rates of the estimates of both the parametric and the nonparametric part of the model are given and quasi-minimax optimality is obtained under usual conditions in literature. We establish in particular that the LASSO penalty leads to an adaptive estimation with respect to the regularity of the estimated function. An algorithm based on backfitting and Fisher-scoring is also proposed for implementation. Simulations are used to illustrate the finite sample behaviour, including a comparison with kernel and splines based methods