Evaluation of the characteristics of a field emission cathode for use in a Mercury ion trap frequency standard

The performance is reported of a field emission array characterized for the purpose of replacing the filament in a trapped ion frequency standard. This dark electron emitter eliminates the need for the interference filter currently used in the trapped ion standard. While reducing the filament's unwanted light, this filter causes a significant reduction in the signal. The magnetic field associated with the filament is also eliminated, thus potentially improving the present stability of the trapped ion standard. The operation of the filament in the present system is described, as well as the associated concerns. The cathode considered for the filament's replacement is then described along with the experimental system. Experimental results, observations, and conclusions are presented

Designing Acellular Injectable Biomaterial Therapeutics for Treating Myocardial Infarction and Peripheral Artery Disease.

As the number of global deaths attributed to cardiovascular disease continues to rise, viable treatments for cardiovascular events such as myocardial infarction (MI) or conditions like peripheral artery disease (PAD) are critical. Recent studies investigating injectable biomaterials have shown promise in promoting tissue regeneration and functional improvement, and in some cases, incorporating other therapeutics further augments the beneficial effects of these biomaterials. In this review, we aim to emphasize the advantages of acellular injectable biomaterial-based therapies, specifically material-alone approaches or delivery of acellular biologics, in regards to manufacturability and the capacity of these biomaterials to regenerate or repair diseased tissue. We will focus on design parameters and mechanisms that maximize therapeutic efficacy, particularly, improved functional perfusion and neovascularization regarding PAD and improved cardiac function and reduced negative left ventricular (LV) remodeling post-MI. We will then discuss the rationale and challenges of designing new injectable biomaterial-based therapies for the clinic

Female Enrollment in Technology Education in Virginia During the 1993/1994 School Year

The problem of the study was to determine if a significant difference exists between male and female enrollment in the approved technology education courses offered as electives in Virginia for the 1993/1994 school year

Enhancing Apprentice Training Through Supervision of Work Experience

To remain globally competitive, U.S. companies need to consider new strategies for developing a workforce. The apprenticeship model has been identified as a viable solution for companies to invest. The problem of this study was to determine if an apprenticeship experience was enhanced by the type of supervision given during the work-related component of a program. To aid current and potential companies offering apprenticeship programs, this study identified a population of apprentices (N = 877), tracked them from entry into the program until five years after graduating, and analyzed their outcomes relative to program completion, academic GPA, work-related GPA, company longevity, and company promotion between those apprentices that were supervised under three unique supervision conditions. Finding significant differences between supervision type relative to completion, academic and work-related GPA\u27s, and promotion, the study concluded that the apprenticeship experience was enhanced by the type of supervision given during the work-related component of the program

Hot-wire Anemometer Behaviour In Low Velocity Air Flow

The behavior characteristics of a commercially available hot-wire anemometer have been examined in the presence of low velocities, lwss than 0.1 m/s for the most part, and in both horizontal and vertical air flows. The orientation of the probe in a horizontal flow has been found to have a definite effect on velocity measurements, and a lower limit to the reliable application of hot-wire anemometry has been evaluated for a particular type of probe. Vertical flow measurements have resulted in the discovery of the magnitude of natural convective velocity, and a possible method for determining the dimensions of the temperature jump distance has been developed indirectly from the description of the shape of the calibration curve

Biomaterials for the Treatment of Myocardial Infarction

For nearly a decade, researchers have investigated the possibility of cell transplantation for cardiac repair. More recently, the emerging fields of tissue engineering and biomaterials have begun to provide potential treatments. Tissue engineering approaches are designed to repair lost or damaged tissue through the use of growth factors, cellular transplantation, and biomaterial scaffolds. There are currently 3 biomaterial approaches for the treatment of myocardial infarction (MI). The first involves polymeric left ventricular restraints in the prevention of heart failure. The second utilizes in vitro engineered cardiac tissue, which is subsequently implanted in vivo. The final approach entails injecting cells and/or a scaffold into the myocardium to create in situ engineered cardiac tissue. This review gives an overview of the current progress in the growing field of biomaterials for the treatment of MI

Acellular Injectable Biomaterials for Treating Cardiovascular Disease

In the last decade, the field of tissue engineering has emerged as a potential therapeutic strategy for the regeneration and/or repair of various tissues afflicted by cardiovascular disease, such as myocardial infarction (MI) or peripheral artery disease (PAD). Among the different tissue engineering strategies, injectable hydrogels have been extensively studied and show encouraging results in both small and large animal models. An injectable hydrogel provides a favorable microenvironment for endogenous regeneration or repair, and depending on the material's design can be used either alone or as a carrier to deliver therapeutic molecules or stem cells. The type of injectable biomaterial is key for a successful hydrogel-based treatment, and in this chapter, we will focus on acellular injectable biomaterial approaches for both MI and PAD

Making A Difference: Year Two Report of the Pennsylvania High School Coaching Initiative

This report examines the implementation of the second year of three for the Pennsylvania High School Coaching Initiative (PAHSCI). Funded by the Annenberg Foundation, this initiative focuses on literacy and math coaches providing support to teachers from across the major subject areas to create literacy-rich classrooms in which students actively engage in learning tasks that deepen their content knowledge and strengthen their abilities to think critically and communicate well. This report presents findings from the first two years of research. It includes survey research as well as in-depth qualitative research in participating schools and districts and provides recommendations for PAHSCI stakeholders as they refine the program and for other education reformers as they consider the benefits of instructional coaching as a strategy for improving high schools and student achievement

Battery-Operated Atomic Force Microscope

The design of a battery-operated atomic force microscope (AFM) using a piezoresistive cantilever is described. The AFM is designed so that all power to drive the scanning tube and detection electronics comes from a self-contained battery. The prototype AFM uses a 6 V, Ni–Cd, camcorder battery, however, any battery that supplies between 6 and 12 V may be used. Scanner control and data acquisition are implemented using commercially available software running on an external computer. The prototype AFM achieves a scan area of 53 by 53 μm, consumes 1.8 W of power, and can scan continuously for about 7 h on a single battery charge