Permeability of a one-dimensional potential barrier

Permeability of one dimensional potential barrie

A Z_3-graded generalization of supermatrices

We introduce Z_3-graded objects which are the generalization of the more familiar Z_2-graded objects that are used in supersymmetric theories and in many models of non-commutative geometry. First, we introduce the Z_3-graded Grassmann algebra, and we use this object to construct the Z_3-matrices, which are the generalizations of the supermatrices. Then, we generalize the concepts of supertrace and superdeterminant

A molecular superfluid: non-classical rotations in doped para-hydrogen clusters

Clusters of para-hydrogen (pH2) have been predicted to exhibit superfluid behavior, but direct observation of this phenomenon has been elusive. Combining experiments and theoretical simulations, we have determined the size evolution of the superfluid response of pH2 clusters doped with carbon dioxide (CO2). Reduction of the effective inertia is observed when the dopant is surrounded by the pH2 solvent. This marks the onset of molecular superfluidity in pH2. The fractional occupation of solvation rings around CO2 correlates with enhanced superfluid response for certain cluster sizes

Challenges for Water Researchers in Alberta in a Climate of Policy Uncertainty

A safe and plentiful supply of surface water is crucial to the well-being of every resident of Alberta. The effective and efficient use of surface water is central to economic growth and environmental sustainability. As the necessary but competing demands on surface water intensify, the awareness of its limited supply increases. This is particularly evident in southern Alberta, which has experienced significant agricultural, industrial and population growth. In addition to its use for extensive irrigation, surface water in the South Saskatchewan River basin is vital to meet drinking and sanitation needs in rural and urban communities. Management of this key resource involves many researchable issues– water supply, water treatment, water distribution, wastewater collection and processing, flood control, navigation, hydropower production, aquatic recreation – which interact with each other and with government policies. The purpose of this article is to outline the priorities for socio-economic research on surface water resource issues in light of the ever-changing legal and policy frameworks in Alberta.Resource /Energy Economics and Policy,

Business orientation and the food security status of small scale producers in the Venda region, South Africa

Questions addressed in this paper are: How to determine the food status of rural households; and does an agribusiness orientation enhance the food security status of farm families. A study was conducted on two groups of small scale black farmers in the Venda region: one group, agribusiness directed and generally more progressive towards technology, produces mangos and other subtropical fruits (cash crop farmers); the other group concentrates on locally consumed and sold vegetables (food crop farmers). Their food status was quantitatively determined by means of household energy, protein and fat balances and food security determinants were identified. More than 80% of the households had a negative balance for energy, protein or fat. Business orientation and farming type in this particular case study does not influence the energy, protein and fat coverage significantly. The marginal nature of farming by these small holders could explain this finding. Significant predictors of food security status were rather factors such as the household size and the availability of outside sources of income and cash to spend on food.Agribusiness, Food Security and Poverty,

Hybridizing two-step growth mixture model and exploratory factor analysis to examine heterogeneity in nonlinear trajectories

Empirical researchers are usually interested in investigating the impacts of baseline covariates have when uncovering sample heterogeneity and separating samples into more homogeneous groups. However, a considerable number of studies in the structural equation modeling (SEM) framework usually start with vague hypotheses in terms of heterogeneity and possible reasons. It suggests that (1) the determination and specification of a proper model with covariates is not straightforward, and (2) the exploration process may be computational intensive given that a model in the SEM framework is usually complicated and the pool of candidate covariates is usually huge in the psychological and educational domain where the SEM framework is widely employed. Following \citet{Bakk2017two}, this article presents a two-step growth mixture model (GMM) that examines the relationship between latent classes of nonlinear trajectories and baseline characteristics. Our simulation studies demonstrate that the proposed model is capable of clustering the nonlinear change patterns, and estimating the parameters of interest unbiasedly, precisely, as well as exhibiting appropriate confidence interval coverage. Considering the pool of candidate covariates is usually huge and highly correlated, this study also proposes implementing exploratory factor analysis (EFA) to reduce the dimension of covariate space. We illustrate how to use the hybrid method, the two-step GMM and EFA, to efficiently explore the heterogeneity of nonlinear trajectories of longitudinal mathematics achievement data.Comment: Draft version 1.6, 08/08/2020. This paper has not been peer reviewed. Please do not copy or cite without author's permissio