Microplastics Detected in Groundwater

Low concentrations of microplastics are present in Illinois’ karst groundwater, according to a preliminary study completed in spring 2018. This is the first time that microplastics have been detected in groundwater. The study was conducted in collaboration with scientists at the Illinois State Geological Survey, Illinois State Water Survey, Loyola University Chicago, and ISTC. Full study results published in Panno, S.V., Kelly, W.R., Scott, J., Zheng, W., McNeish, R.E., Holm, N., Hoellein, T.J. and Baranski, E.L. (2019), Microplastic Contamination in Karst Groundwater Systems. Groundwater, 57: 189-196. doi:10.1111/gwat.12862.League of Women Voters of Jo Daviess County; Illinois State Geological Survey; Illinois State Water Survey; Illinois Sustainable Technology Center (Hazardous Waste Research Fund);. Illinois-Indiana Sea Grant (National Oceanic and Atmospheric Administration ; 074483-15907); National Science Foundation (CAREER 1553835).Ope

Water quality and agrichemical loading in two groundwater basins of Illinois' sinkhole plain

Methods: Groundwater basins. -- Sampling. -- Analyses. -- Results and discussion: Chemical composition of surface water and groundwater. -- Water-borne bacteria. -- Dissolved organic carbon. -- Soil erosion rate. -- Atrazine on suspended solids

Relativistic calculation of nuclear transparency in (e,e'p) reactions

Nuclear transparency in (e,e'p) reactions is evaluated in a fully relativistic distorted wave impulse approximation model. The relativistic mean field theory is used for the bound state and the Pauli reduction for the scattering state, which is calculated from a relativistic optical potential. Results for selected nuclei are displayed in a Q^2 range between 0.3 and 1.8 (GeV/c)^2 and compared with recent electron scattering data. For Q^2 = 0.3 (GeV/c)^2 the results are lower than data; for higher Q^2 they are in reasonable agreement with data. The sensitivity of the model to different prescriptions for the one-body current operator is investigated. The off-shell ambiguities are rather large for the distorted cross sections and small for the plane wave cross sections.Comment: 8 pages, 3 figure

Combined CI+MBPT calculations of energy levels and transition amplitudes in Be, Mg, Ca, and Sr

Configuration interaction (CI) calculations in atoms with two valence electrons, carried out in the V(N-2) Hartree-Fock potential of the core, are corrected for core-valence interactions using many-body perturbation theory (MBPT). Two variants of the mixed CI+MBPT theory are described and applied to obtain energy levels and transition amplitudes for Be, Mg, Ca, and Sr

The Value of Information for Populations in Varying Environments

The notion of information pervades informal descriptions of biological systems, but formal treatments face the problem of defining a quantitative measure of information rooted in a concept of fitness, which is itself an elusive notion. Here, we present a model of population dynamics where this problem is amenable to a mathematical analysis. In the limit where any information about future environmental variations is common to the members of the population, our model is equivalent to known models of financial investment. In this case, the population can be interpreted as a portfolio of financial assets and previous analyses have shown that a key quantity of Shannon's communication theory, the mutual information, sets a fundamental limit on the value of information. We show that this bound can be violated when accounting for features that are irrelevant in finance but inherent to biological systems, such as the stochasticity present at the individual level. This leads us to generalize the measures of uncertainty and information usually encountered in information theory

Оптимізація паралельного ітераційного процесу для лінійних систем з розрідженими матрицями

Розглядається один із підходів до побудови передобумовлювача для методу спряжених градієнтів розв'язування СЛАР з розрідженими матрицями нерегулярної структури. Запропоновано та досліджено передобумовлювачі на основі методу паралельних перерізів.Рассматривается один из подходов к построению предобуславливателя для метода сопряженных градиентов решения СЛАУ с разреженными матрицами нерегулярной структуры. Предложены и исследованы предобуславливатели на основе метода параллельных сечений.Considered is one of approaches for construction a preconditioner for method of conjunctive gradients for solution SLAE with sparse matrices of irregular structure. Preconditioners, which are based on method of parallel section, is proposed and investigated

The State of the Art in Language Workbenches. Conclusions from the Language Workbench Challenge

Language workbenches are tools that provide high-level mechanisms for the implementation of (domain-specific) languages. Language workbenches are an active area of research that also receives many contributions from industry. To compare and discuss existing language workbenches, the annual Language Workbench Challenge was launched in 2011. Each year, participants are challenged to realize a given domain-specific language with their workbenches as a basis for discussion and comparison. In this paper, we describe the state of the art of language workbenches as observed in the previous editions of the Language Workbench Challenge. In particular, we capture the design space of language workbenches in a feature model and show where in this design space the participants of the 2013 Language Workbench Challenge reside. We compare these workbenches based on a DSL for questionnaires that was realized in all workbenches

Calibration of a Neutron Polarimeter

This research was sponsored by the National Science Foundation Grant NSF PHY-931478