Regenerable biocide delivery unit

A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, as well as treatment of water supplies on Earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I-(sub n) at the anion exchange sites and releases I(sub 2) into the water stream flowing through the bed. The concentration of I(sub 2) in the flowing water gradually decreases and, in the prior art, the ion-exchange bed has had to be replaced. In a preferred embodiment, a bed of iodine crystals is provided with connections for flowing water therethrough to produce a concentrated (substantially saturated) aqueous iodine solution which is passed through the iodinated resin bed to recharge the bed with bound iodine. The bed of iodine crystals is connected in parallel with the iodinated resin bed and is activated periodically (e.g., by timer, by measured flow of water, or by iodine residual level) to recharge the bed. Novelty resides in the capability of inexpensively and repeatedly regenerating the ion-exchange bed in situ

Concentration of Vacancies at Metal Oxide Surfaces: Case Study of MgO (100)

We investigate effects of doping on formation energy and concentration of oxygen vacancies at a metal oxide surface, using MgO (100) as an example. Our approach employs density-functional theory, where the performance of the exchange-correlation functional is carefully analyzed, and the functional is chosen according to a fundamental condition on DFT ionization energies. The approach is further validated by CCSD(T) calculations for embedded clusters. We demonstrate that the concentration of oxygen vacancies at a doped oxide surface is largely determined by formation of a macroscopically extended space charge region

Extension of the Schiff theorem to ions and molecules

According to the Schiff theorem the nuclear electric dipole moment (EDM) is screened in neutral atoms. In ions this screening is incomplete. We extend a derivation of the Schiff theorem to ions and molecules. The finite nuclear size effects are considered including Z^2 alpha^2 corrections to the nuclear Schiff moment which are significant in all atoms and molecules of experimental interest. We show that in majority of ionized atoms the nuclear EDM contribution to the atomic EDM dominates while in molecules the contribution of the Schiff moment dominates. We also consider the screening of electron EDM in ions

Measuring the Efficiency Effect of Banning Anti-Microbial Growth Promoters: The Case of Danish Pig Production

This study examines the effect of banning antimicrobial growth promoters on efficiency in the production of weaned and slaughter (finishing) pigs. We focus on the reaction of producers and production efficiency. We evaluate the estimated output and input shadow prices relative to market prices to analyse producer reactions and capture the impact on production efficiency by evaluating the effects of the ban changes on total factor productivity. To this end we model a multi product shadow profit function and incorporate output and input related shadow prices by using a second order flexible functional form. The development in total factor productivity is subsequently measured by calculating the Malmquist index on the farm level. To make infer-ences on the effect of banning growth promoters over time we regress in a second estimation step the changes in total factor productivity on potential explanatory factors by applying a bootstrapped censored regression procedure. Our results suggest that there was no effect of the ban on total factor productivity due to outputs and inputs substitution. Breeding pigs are pro-duced at the expense of weaned and finisher pigs. Feed input is over utilised relative to other inputs. The high shadow prices for substituting outputs are associated with better export mar-ket prices. These findings may have critical implications for the slaughtering plants with over capacity.animal health economics, food economics, shadow prices, efficiency, antimicrobial growth promoters, pig production, Livestock Production/Industries, Q1, Q11, Q12, Q24,

Creating and selling embryos for “donation”: ethical challenges

The commercial creation and sale of embryos has begun, which poses a series of ethical questions that have received little scholarly attention. Some of the concerns that arise are similar to those posed by the sale of gametes, while other issues differ markedly. Questions emerge, first, regarding the rights of the unborn children and their ability to know their biological parents. Companies that create human embryos de novo may wish to keep gamete providers anonymous. Many of these offspring thus will never learn that their parents are not their biologic parents. Yet, such disclosures, regarding not only one but both of these biologic parents, may be important for these individuals; and a lack of this knowledge may impede their physical and psychological health. Second, questions surface regarding the fees that providers should charge for embryos and whether these amounts should vary based on the traits of 1 or both of the gamete donors. Some prospective parents may seek specific traits in a baby (eg, height or eye/hair coloring), which prompts the creation of embryos from 2 gamete donors who possess these characteristics. Third, ownership of embryos created without an advanced directive by patients poses dilemmas (eg, disposition of any remaining embryos). Fourth, guidelines do not yet exist to limit the number of embryos sold from each pair of gamete donors. Hence, unbeknownst to each other, full siblings could potentially meet, get married, and procreate. This discussion has several critical implications for future practice and professional education and policy. Patients with diseases associated with genetic tests may well ask obstetricians, gynecologists, and other physicians about these techniques and practices. Clinicians can refer such patients to assisted reproductive technology specialists; however, familiarity with the basic aspects of the issues and complexities involved could aid these providers and their patients Several of these issues can be addressed relatively easily through guidelines from professional associations (eg, limiting the number of embryos sold from each pair of gamete donors). Because creation and sales of embryos will likely spread, consideration of appropriate responses is critical to establish standards of care to help the future offspring, and ensure ongoing public trust

Slowing heavy, ground-state molecules using an alternating gradient decelerator

Cold supersonic beams of molecules can be slowed down using a switched sequence of electrostatic field gradients. The energy to be removed is proportional to the mass of the molecules. Here we report deceleration of YbF, which is 7 times heavier than any molecule previously decelerated. We use an alternating gradient structure to decelerate and focus the molecules in their ground state. We show that the decelerator exhibits the axial and transverse stability required to bring these molecules to rest. Our work significantly extends the range of molecules amenable to this powerful method of cooling and trapping.Comment: 4 pages, 5 figure

Ground states of Heisenberg evolution operator in discrete three-dimensional space-time and quantum discrete BKP equations

In this paper we consider three-dimensional quantum q-oscillator field theory without spectral parameters. We construct an essentially big set of eigenstates of evolution with unity eigenvalue of discrete time evolution operator. All these eigenstates belong to a subspace of total Hilbert space where an action of evolution operator can be identified with quantized discrete BKP equations (synonym Miwa equations). The key ingredients of our construction are specific eigenstates of a single three-dimensional R-matrix. These eigenstates are boundary states for hidden three-dimensional structures of U_q(B_n^1) and U_q(D_n^1)$.Comment: 13 page