Spectral bounds for the cutoff Coulomb potential

The method of potential envelopes is used to analyse the bound-state spectrum of the Schroedinger Hamiltonian H = -Delta -v/(r+b), where v and b are positive. We established simple formulas yielding upper and lower energy bounds for all the energy eigenvalues.Comment: 11 pages, 2 figure

The Economic Loss Doctrine as an Obstacle to Claims of Contractual Strangers.

Home owners, contractors, and subcontractors entering a contract to build in accordance with another’s design must be aware of their respective risks under the economic loss doctrine. The economic loss doctrine bars recovery due purely to economic loss by a party that is a contractual stranger. In a typical construction contract, a homeowner may separately contract with a contractor and a design professional. In this situation, the contractor does not have privity with the design professional and the economic loss doctrine bars the contractor from suing the design professional for economic loss. Likewise, if the homeowner hires a contractor and the contractor hires the design professional, the homeowner is barred by the economic loss doctrine from suing the design professional for economic loss. The Texas Supreme Court has recognized some exceptions to the economic loss doctrine. If the plaintiff can prove physical damage beyond the “subject matter of the contract,” the plaintiff can allege an independent negligence claim notwithstanding the existence of a contract because an independent duty exists not to negligently damage property. Nonetheless, it is imperative that each party—owner, contractor, and subcontractor—entering into a contract be familiar with the terms and their respective remedies. This is especially true if the project is to be built in accordance with a design professional’s design. Each respective party must be careful to allocate, limit, insure or otherwise transfer and manage its exposure to economic loss that may result from the insufficiency of a design and the failure of its contractual expectation

The Economic Loss Doctrine as an Obstacle to Claims of Contractual Strangers.

Home owners, contractors, and subcontractors entering a contract to build in accordance with another’s design must be aware of their respective risks under the economic loss doctrine. The economic loss doctrine bars recovery due purely to economic loss by a party that is a contractual stranger. In a typical construction contract, a homeowner may separately contract with a contractor and a design professional. In this situation, the contractor does not have privity with the design professional and the economic loss doctrine bars the contractor from suing the design professional for economic loss. Likewise, if the homeowner hires a contractor and the contractor hires the design professional, the homeowner is barred by the economic loss doctrine from suing the design professional for economic loss. The Texas Supreme Court has recognized some exceptions to the economic loss doctrine. If the plaintiff can prove physical damage beyond the “subject matter of the contract,” the plaintiff can allege an independent negligence claim notwithstanding the existence of a contract because an independent duty exists not to negligently damage property. Nonetheless, it is imperative that each party—owner, contractor, and subcontractor—entering into a contract be familiar with the terms and their respective remedies. This is especially true if the project is to be built in accordance with a design professional’s design. Each respective party must be careful to allocate, limit, insure or otherwise transfer and manage its exposure to economic loss that may result from the insufficiency of a design and the failure of its contractual expectation

Evaluation of Nitrogen and Phosphorus Enrichment Using In Situ Enclosure Bags with Temporal Indigenous Phytoplankton Populations

An in situ experimental procedure and protocol was developed to evaluate nitrate and phosphate enrichment using isolated indigenous phytoplankton assemblages during different seasons. Results of the comparison of the parameters-temperature, pH, alkalinity, conductivity, and dissolved oxygen between the open water and enclosed systems indicated that there was no significant influence of the physicochemical factors on the isolated biological processes. Growth responses were measured by turbidity, biomass and chlorophyll-a, the most sensitive being chlorophyll-a. Additions of nitrate and phosphate were added in known concentrations and in different magnitudes of concentration based upon ambient conditions and ratio. During the fall, phosphorus influenced phytoplankton growth, whereas in the spring both nutrients effect growth response equally, and in the summer nitrate had the greatest influence. Based upon the results of these experiments a sampling regime for physicochemical parameters and growth response is recommended

Energy bounds for the spinless Salpeter equation: harmonic oscillator

We study the eigenvalues E_{n\ell} of the Salpeter Hamiltonian H = \beta\sqrt(m^2 + p^2) + vr^2, v>0, \beta > 0, in three dimensions. By using geometrical arguments we show that, for suitable values of P, here provided, the simple semi-classical formula E = min_{r > 0} {v(P/r)^2 + \beta\sqrt(m^2 + r^2)} provides both upper and lower energy bounds for all the eigenvalues of the problem.Comment: 8 pages, 1 figur

Spectra generated by a confined softcore Coulomb potential

Analytic and approximate solutions for the energy eigenvalues generated by a confined softcore Coulomb potentials of the form a/(r+\beta) in d>1 dimensions are constructed. The confinement is effected by linear and harmonic-oscillator potential terms, and also through `hard confinement' by means of an impenetrable spherical box. A byproduct of this work is the construction of polynomial solutions for a number of linear differential equations with polynomial coefficients, along with the necessary and sufficient conditions for the existence of such solutions. Very accurate approximate solutions for the general problem with arbitrary potential parameters are found by use of the asymptotic iteration method.Comment: 17 pages, 2 figure

Farmwork-Related Injury Among Farmers 50 Years of Age and Older in Kentucky and South Carolina: A Cohort Study, 2002-2005

Farmers in the U.S. are becoming more diverse; the average age of the farmer is increasing, as is the number of women and minority farm operators. There is limited research on injury risk factors in these special populations of farmers. It is especially important to study the risk factors for injury in these growing and at-risk groups. A longitudinal survey was conducted of farmers (n = 1,394) age 50 and older who resided in Kentucky and South Carolina. The questionnaire was administered by telephone and mail surveys four times between 2002 and 2005 to the fixed cohort of farmers, obtained by convenience sample. Approximately half of the cohort was female, and the majority of the cohort worked less than 40 hours per week. This cohort reported a crude, non-fatal injury rate of 9.3 injured farmers per 100 per year. Farmers reporting chronic bronchitis/emphysema (estimated odds ratio [EOR] = 1.57), back problems (EOR = 1.37), arthritis (EOR = 1.31), 3 to 4 restless nights in the past week (EOR = 2.02), or 5 to 7 restless nights in the past week (EOR = 1.82) were at significantly higher odds of sustaining a farmwork-related injury as calculated by the generalized estimating equations (GEE) regression method Farmers operating equipment on highways (EOR = 1.51) or climbing higher than eight feet (EOR = 1.69) were at significantly higher odds of sustaining a farmwork-related injury, and females were at higher risk of injury when performing animal-related tasks (EOR = 3.00) or crop-related tasks (EOR = 2.21). Identified factors associated with farmwork-related injury should better inform agricultural health policies and guidelines for older farmers, such as policies governing the allowable number of hours worked per week and rest breaks, guidelines that advise appropriate types of farm tasks, and ergonomic engineering advances on farming equipment