The Effect of the Pairing Interaction on the Energies of Isobar Analog Resonances in 112−124^{112-124}Sb and Isospin Admixture in 100−124^{100-124}Sn Isotopes

In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analog resonances (IAR) in $^{112-124}$Sb isotopes and the isospin admixture in $^{100-124}$Sn isotopes is investigated within the framework of the quasiparticle random phase approximation (QRPA). The form of the interaction strength parameter is related to the shell model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the $^{100-124}$Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral $J_{F}$ for the Sn($^{3}$He,t)Sb reactions at E($^{3}$He)$=200$ MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the $^{100}$Sn isotope is in good agreement with Colo et al.'s estimates $(4-5$, and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al. (53$\pm$5 MeV fm$^{3}$). Moreover, it is concluded that although the differential cross section of the isobar analog resonance for the ($^{3}$He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in $N\approx Z$ isotopes can be seen with the presence of these correlations.Comment: 16 pages, 5 EPS figures and 2 tables, Late

Detection of metastable electronic states by Penning trap mass spectrometry

State-of-the-art optical clocks achieve fractional precisions of $10^{-18}$ and below using ensembles of atoms in optical lattices or individual ions in radio-frequency traps. Promising candidates for novel clocks are highly charged ions (HCIs) and nuclear transitions, which are largely insensitive to external perturbations and reach wavelengths beyond the optical range, now becoming accessible to frequency combs. However, insufficiently accurate atomic structure calculations still hinder the identification of suitable transitions in HCIs. Here, we report on the discovery of a long-lived metastable electronic state in a HCI by measuring the mass difference of the ground and the excited state in Re, the first non-destructive, direct determination of an electronic excitation energy. This result agrees with our advanced calculations, and we confirmed them with an Os ion with the same electronic configuration. We used the high-precision Penning-trap mass spectrometer PENTATRAP, unique in its synchronous use of five individual traps for simultaneous mass measurements. The cyclotron frequency ratio $R$ of the ion in the ground state to the metastable state could be determined to a precision of $\delta R=1\cdot 10^{-11}$, unprecedented in the heavy atom regime. With a lifetime of about 130 days, the potential soft x-ray frequency reference at $\nu=4.86\cdot 10^{16}\,\text{Hz}$ has a linewidth of only $\Delta \nu\approx 5\cdot 10^{-8}\,\text{Hz}$, and one of the highest electronic quality factor ($Q=\frac{\nu}{\Delta \nu}\approx 10^{24}$) ever seen in an experiment. Our low uncertainty enables searching for more HCI soft x-ray clock transitions, needed for promising precision studies of fundamental physics in a thus far unexplored frontier

Quantum chemical and experimental studies on the mechanism of alkylation of beta-dicarbonyl compounds. The synthesis of five and six membered heterocyclic spiro derivatives

WOS: 000227831900003PubMed ID: 18007493The alkylation of beta-dicarbonyl compounds in a K2CO3/DMSO system was found to afford O- and C-alkylated derivatives, depending on the type of the P-dicarbonyl compound involved. The alkyl derivatives obtained were used in the synthesis of some new spiro barbituric acid derivatives. Quantum chemical calculations were carried out to elucidate the reaction mechanisms for some typical synthesis

Energy Response and Longitudinal Shower Profiles Measured in CMS HCAL and Comparison With Geant4

The response of the CMS combined electromagnetic and hadron calorimeter to beams of pions with momenta in the range 5-300 GeV/c has been measured in the H2 test beam at CERN. The raw response with the electromagnetic compartment calibrated to electrons and the hadron compartment calibrated to 300 GeV pions may be represented by sigma = (1.2) sqrt{E} oplus (0.095) E. The fraction of energy visible in the calorimeter ranges from 0.72 at 5 GeV to 0.95 at 300 GeV, indicating a substantial nonlinearity. The intrinsic electron to hadron ratios are fit as a function of energy and found to be in the range 1.3-2.7 for the electromagnetic compartment and 1.4-1.8 for the hadronic compartment. The fits are used to correct the non-linearity of the e pi response to 5% over the entire measured range resulting in a substantially improved resolution at low energy. Longitudinal shower profile have been measured in detail and compared to Geant4 models, LHEP-3.7 and QGSP-2.8. At energies below 30 GeV, the data, LHEP and QGSP are in agreement. Above 30 GeV, LHEP gives a more accurate simulation of the longitudinal shower profile

Design, Performance, and Calibration of CMS Hadron Endcap Calorimeters

Detailed measurements have been made with the CMS hadron calorimeter endcaps (HE) in response to beams of muons, electrons, and pions. Readout of HE with custom electronics and hybrid photodiodes (HPDs) shows no change of performance compared to readout with commercial electronics and photomultipliers. When combined with lead-tungstenate crystals, an energy resolution of 8\% is achieved with 300 GeV/c pions. A laser calibration system is used to set the timing and monitor operation of the complete electronics chain. Data taken with radioactive sources in comparison with test beam pions provides an absolute initial calibration of HE to approximately 4\% to 5\%

Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter

The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS

A STUDY OF THE IMPACT OF THE 2008-2009 GLOBAL CRISIS IN EASTERN EUROPE AND CENTRAL ASIA: RETAILERS’ AND CORE INDUSTRY FIRMS’ FIXED ASSET PURCHASES

This paper investigates the impact of the 2008-2009 Crisis on retailers and core industry firms in Eastern Europe and Central Asia. Utilizing the World Bank’s BEEPS IV (for pre-Crisis) and V (for post-Crisis) survey data, we look at the timing of payment of fixed assets purchased as well as how these firms paid for their purchases of fixed assets, i.e., financing by internal funds, financing by owner’s contribution, and financing by supplier credit. We find that the percentage of customers of retailers and core industry firms paying after delivery had declined post-Crisis. Such finding suggests that these firms had tightened up their credit policies which resulted in more customers paying before deliveries. We also find that the use of internal funds by both retailers and core industry firms significantly increased post-Crisis. As such, we also find that the use of owner’s distribution (new shares) and supplier credit significantly decreased post-Crisis, for both retailers and core industry firms. These findings are consistent with prior studies which suggest more stringent credit requirements following a crisis. This results in a change in firms’ capital structure

Neural network models for flexible pavement structural evaluation

In this study, multilayer pavement structure is simplified into one layer of equivalent thickness by using Equivalent Layer Theory (ELT). Artificial Neural Network (ANN)-based pavement structural analysis models were developed to find an equivalent thickness and elastic modulus of the modeled pavement system. The synthetic databases used as inputs in ANN forward and back-calculation models were created using MnLayer, a Layered Elastic Analysis (LEA) program. ANN models were trained to obtain the critical responses at the top and bottom of such layers in pavement systems. The multilayered flexible pavements were subjected to one 20 kips of Falling Weight Deflectometer (FWD) load in a circular area and with uniform pressure. ANN models were found to represent a useful alternative approach for not only determining equivalent thickness and modulus but also providing close estimate of deflections of a multilayered flexible pavement system.This is a manuscript of a proceeding published as Citir, N., H. Ceylan, and S. Kim. "Neural network models for flexible pavement structural evaluation." In Advances in Materials and Pavement Performance Prediction II, pp. 28-31. CRC Press, 2020. doi: http://dx.doi.org/10.1201/9781003027362-7. Copyright 2020 Taylor & Francis Group, London. Posted with permission

Design, Performance and Calibration of the CMS Forward Calorimeter Wedges

We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%

Determination of Primary Surface Water Pollution Indicators by Multivariate Statistical Techniques in an Industrialized Basin

This study aimed to investigate the point and diffuse pollution sources of high total phosphorus (TP) pollution detected in the dry and wet seasons of the industrialized and urbanized Saz-Cayirova Basin through field observation and multivariate statistical techniques. In this context, nineteen water quality parameters were analyzed in surface water samples collected monthly between June 2020 and July 2021 from nineteen different sites along the Saz-Cayirova stream. Firstly, two reference sites representing a better surface water status were determined and assessed the water quality on the stream tributaries affecting the wastewater treatment plant in the two Organized Industrial Zones (OIZ). Secondly, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were performed to evaluate the complex water quality dataset and reveal the latent sources of TP pollution. The results showed that the tributaries in the pressure of OIZ discharges were highly enriched in COD, TOC, NO3-N, NH3-N, and TP concentrations compared to the reference level. Compared with reference sites, the concentrations of the four heavy metals examined were at a plausible level. Besides, the pollution sources of TP were industrial processes wastewater such as dyeing, washing, phosphating, domestic wastewater from OIZ, urban diffuse waters with organic character, and continuous discharges of undefined sources. The seasonal variation of TP values is observed relatively low, indicating that the stream network is greatly affected by point source pollution. Our observation and analysis imply that the treatment technologies adopted by the OIZ wastewaters plant is sufficient to treat heavy metals. However, measures need to be formulated to remove TP and organic pollution from the secondary production process. © 2022, Avestia Publishing. All rights reserved