Separation of bacterial spores from flowing water in macro-scale cavities by ultrasonic standing waves

The separation of micron-sized bacterial spores (Bacillus cereus) from a steady flow of water through the use of ultrasonic standing waves is demonstrated. An ultrasonic resonator with cross-section of 0.0254 m x 0.0254 m has been designed with a flow inlet and outlet for a water stream that ensures laminar flow conditions into and out of the resonator section of the flow tube. A 0.01905-m diameter PZT-4, nominal 2-MHz transducer is used to generate ultrasonic standing waves in the resonator. The acoustic resonator is 0.0356 m from transducer face to the opposite reflector wall with the acoustic field in a direction orthogonal to the water flow direction. At fixed frequency excitation, spores are concentrated at the stable locations of the acoustic radiation force and trapped in the resonator region. The effect of the transducer voltage and frequency on the efficiency of spore capture in the resonator has been investigated. Successful separation of B. cereus spores from water with typical volume flow rates of 40-250 ml/min has been achieved with 15% efficiency in a single pass at 40 ml/min.Comment: 11 pages, 6 figure

Alien Registration- Dionne, Elisee J. (Van Buren, Aroostook County)

https://digitalmaine.com/alien_docs/33434/thumbnail.jp

The Costs and Benefits of Reinsurance

Purchasing reinsurance reduces insurers’ insolvency risk by stabilizing loss experience, increasing capacity, limiting liability on specific risks, and/or protecting against catastrophes. Consequently, reinsurance purchase should reduce capital costs. However, transferring risk to reinsurers is expensive. The cost of reinsurance for an insurer can be much larger than the actuarial price of the risk transferred. In this article, we analyze empirically the costs and the benefits of reinsurance for a sample of U.S. property-liability insurers. The results show that reinsurance purchase increases significantly the insurers’ costs but reduces significantly the volatility of the loss ratio. With purchasing reinsurance, insurers accept to pay higher costs of insurance production to reduce their underwriting risk.reinsurance, insolvency risk, risk management, financial intermediation, cost functions, panel data.

Efficiency of Insurance Firms with Endogenous Risk Management and Financial Intermediation Activities

Risk management is now present in many economic sectors. This paper investigates the role of risk management in creating value for financial institutions by analyzing U.S. property-liability insurers. Property-liability insurers are financial intermediaries whose primary roles in the economy are risk pooling and risk bearing. The risk pooling and risk bearing functions performed by insurers are the primary determinants of the need for risk management. The main goal of this paper is to test how risk management and financial intermediation activities create value for insurers by enhancing economic efficiency. Insurer cost efficiency is measured relative to an econometric cost function. Since the prices of risk management and financial intermediation services are not observable, we consider these two activities as intermediate outputs and estimate their shadow prices. The shadow prices isolate the contributions of risk management and financial intermediation to insurer cost efficiency. The econometric results show that both activities significantly increase the efficiency of the property-liability insurance industry.Risk management, US property-liability insurer, risk pooling, financial intermediation, economic efficiency, intermediate output, shadow price, cost function, translog approximation

Planar metal plasmon waveguides: frequency-dependent dispersion, propagation, localization, and loss beyond the free electron model

A numerical analysis of surface plasmon dispersion, propagation, and localization on smooth lossy films is presented. Particular attention is given to determining wavelength-dependent behavior of thin Ag slab waveguides embedded in a symmetric SiO2 environment. Rather than considering Ag as a damped free electron gas, the metal is defined by the experimentally determined optical constants of Johnson and Christy and Palik. As in free electron gas models, analytic dispersion results indicate a splitting of plasmon modes—corresponding to symmetric and antisymmetric field distributions—as film thickness is decreased below 50 nm. However, unlike free electron gas models, the surface plasmon wave vector remains finite at resonance with the antisymmetric-field plasmon converging to a pure photon mode for very thin films. In addition, allowed excitation modes are found to exist between the bound and radiative branches of the dispersion curve. The propagation characteristics of all modes are determined, and for thin films (depending upon electric field symmetry), propagation distances range from microns to centimeters in the near infrared. Propagation distances are correlated with both the field decay (skin depth) and energy density distribution in the metal and surrounding dielectric. While the energy density of most long-range surface plasmons exhibits a broad spatial extent with limited confinement in the waveguide, it is found that high-field confinement does not necessarily limit propagation. In fact, enhanced propagation is observed for silver films at ultraviolet wavelengths despite strong field localization in the metal. The surface plasmon characteristics described in this paper provide a numerical springboard for engineering nanoscale metal plasmon waveguides, and the results may provide a new avenue for integrated optoelectronic applications

Efficiency of Insurance Firms with Endogenous Risk Management and Financial Intermediation Activities

Risk management is now present in many economic sectors. This paper investigates the role of risk management in creating value for financial institutions by analyzing U.S. property-liability insurers. Property-liability insurers are financial intermediaries whose primary role in the economy is risk pooling and risk bearing. The risk pooling and risk bearing functions performed by insurers are the primary determinants of the need for risk management. The main goal of this paper is to test how risk management and financial intermediation activities create value for insurers by enhancing economic efficiency. Insurer cost efficiency is measured relative to an econometric cost frontier. Since the prices of risk management and financial intermediation services are not observable, we consider these two activities as intermediate outputs and estimate their shadow prices. The shadow prices isolate the contributions of risk management and financial intermediation to insurer cost efficiency. The econometric results show that both activities significantly increase the efficiency of the property-liability insurance industry.

A Report on the Media and the Immigration Debate

Analyzes media coverage of immigration since 1980 and how industry practices and new media have conditioned the public to associate immigration with illegality, crisis, controversy, and government failure, causing a stalemate in the policy debate

AFRICAN AMERICAN MEN\u27S PROSTATE CANCER KNOWLEDGE AND SELF-EFFICACY FOR INFORMED DECISION-MAKING: A MIXED METHODS STUDY

A mixed methods study was conducted whereby, the quantitative portion has a randomized control design, in an urban Delaware community to examine the effectiveness of an educational intervention, which included the testimony of an African American (AA) prostate cancer survivor on AA men’s (n=98) prostate cancer knowledge and self-efficacy for informed decision making. Guided by Bandura’s Social Cognitive theory, participants’ prostate cancer knowledge measured by PROCASE and for self-efficacy measured by the Prostate Cancer Screening Self-efficacy scale, were evaluated before and following viewing of the American Cancer Society’s prostate cancer video. Participants randomized to the intervention completed evaluations after the intervention. A sample (n=10) from each group participated in their respective focus groups. A control focus group (those who neither watched video or heard speaker) was also evaluated. The MANCOVA, using Pillai’s trace, demonstrated a significant effect of the intervention on knowledge and self-efficacy posttest scores, (V= .28, F6,82 = 4.937, p= .000). Combining a prostate cancer survivor’s testimonial with an educational video increases knowledge and self-efficacy among AA men in this urban community

Public-Private Partnerships Extend Community-based Organization’s Longevity

Public/private partnerships are essential to the survival of mission-driven non-profits, especially those in aging services. Aging service nonprofits receive less than two percent of all institutional philanthropic dollars, with a largest segment of their funding provided by government entities. Carter Burden Network (CBN) is an aging services nonprofit organization serving community-dwelling seniors in Manhattan, with a concentration of services in East Harlem, Roosevelt Island, and the Upper East Side. The NYC Department for the Aging and other government sources provide 50 percent of CBN’s budget. The adage that ‘government cannot do it alone’ is exemplified through CBN’s history of developing new programs through private partnerships, and use of skills-based volunteerism to enhance services. Public/private partnerships have helped CBN strengthen its capacity to expand its service provision and areas. Equally important is CBN’s commitment to increase return on investment for public/private partnerships by reducing food insecurity and malnutrition, hospitalization, and social isolation - all with a financial benefit to the broader society

Nonlinear Competition Between Small and Large Hexagonal Patterns

Recent experiments by Kudrolli, Pier and Gollub on surface waves, parametrically excited by two-frequency forcing, show a transition from a small hexagonal standing wave pattern to a triangular ``superlattice'' pattern. We show that generically the hexagons and the superlattice wave patterns bifurcate simultaneously from the flat surface state as the forcing amplitude is increased, and that the experimentally-observed transition can be described by considering a low-dimensional bifurcation problem. A number of predictions come out of this general analysis.Comment: 4 pages, RevTex, revised, to appear in Phys. Rev. Let