Dementia: Shifting Mystery to Meaning and Management

Asking “Why” tries to find the logical rationale behind current behaviors. With dementia, reasoning is faulty because of the breakdown in the normal brain activity. The questions, “What does this mean?” and, “What must we do?” are catalysts to taking care of the needs and emotions of the whole person. We present our discoveries so that others in the caretaker community may more effectively help their loved ones feel better in spite of the physiological challenges that may face them. Finally, we examine our current potentially confusing habits, which our future caretakers may not understand if roles are changed. The goal in either scenario is to maintain the loving relationship through our narrative

2D Modeling of Bipolar Junction Transistors

The purpose of this report is to summarize the progress to date on the development of a 2D computer model for bipolar junction transistors. The goals of this project, which ends December 31, 1988, can be broken into two main categories and are listed below: Code Modifications 1. Modify existing 2D solar cell simulation code to handle bipolar junction transistors. 2. Incorporate energy balance equations into the computer model. 3. Incorporate transient and small signal ac analyses. Code Applications 1. Assess performance differences between Delco small and large thin epi devices. 2. Evaluate a polysilicon modification of the thin epi process. 3. Provide general analytic support. 4. Investigate extraction of SPICE parameters from simulation results. 5. Provide version of the code to Delco Electronics. The solar cell code, SCAP2D (Solar Cell Analysis Program in 2 Dimensions), has been successfully modified to handle bipolar junction transistors. This code has been named DAP2D (Device Analysis Program in 2 Dimensions). The major weakness of the code at the present time is its inability to model the Delco thin epi device adequately. The structure of this device is sufficiently complicated that computational restrictions in the present version of DAP2D require that simplifying assumptions be made when modeling this device. This problem is being addressed by the installation of a software package which will reduce the restrictions on device structure complexity (Chapter 3). Some simulation results are presented in Chapter 2. The most significant modeling result to date is the prediction that a factor of about 3 improvement in β can be expected with the addition of a polysilicon emitter contact. This result was obtained by assuming that the polysilicon contact can be modeled by an effective contact recombination velocity. Several appendices are also included in this report. Appendix A contains an overview of the numerical methods used to solve the semiconductor equations which are used to model device behavior. A user’s manual for DAP2D is presented in Appendix B. An example simulation is presented in Appendices C and D

Emergence dynamics of barnyardgrass and jimsonweed from two depths when switching from conventional to reduced and no-till conditions

A cylinder experiment was conducted in northern Greece during 2005 and 2006 to assess emergence dynamics of barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and jimsonweed (Datura stramonium L.) in the case of a switch from conventional to conservation tillage systems (CT). Emergence was surveyed from two burial depths (5 and 10 cm) and with simulation of reduced tillage (i.e. by soil disturbance) and no-till conditions. Barnyardgrass emergence was significantly affected by burial depth, having greater emergence from 5 cm depth (96%) although even 78% of seedlings emerged from 10 cm depth after the two years of study. Emergence of barnyardgrass was stable across years from the different depths and tillage regimes. Jimsonweed seeds showed lower germination than barnyardgrass during the study period, whereas its emergence was significantly affected by soil disturbance having 41% compared to 28% without disturbance. A burial depth x soil disturbance interaction was also determined, which showed higher emergence from 10 cm depth with soil disturbance. Jimsonweed was found to have significantly higher emergence from 10 cm depth with soil disturbance in Year 2. Seasonal emergence timing of barnyardgrass did not vary between the different burial depth and soil disturbance regimes, as it started in April and lasted until end of May in both years. Jimsonweed showed a bimodal pattern, with first emergence starting end of April until mid-May and the second ranging from mid-June to mid-August from 10 cm burial depth and from mid-July to mid-August from 5 cm depth, irrespective of soil disturbance in both cases

Voices from the Frontlines:Teachers' Perceptions of High-Stakes Testing

The purpose of this study was to investigate whether teachers perceived Florida’s high-stakes testing program to be taking public schools in the right direction. More importantly, we sought to understand why teachers perceived the tests to be taking schools in the right or wrong direction. Based on the survey results of 708 teachers, we categorized their concerns and praises of high-stakes testing into ten themes. Most of the teachers believed that the testing program was not taking schools in the right direction. They commented that the test was used improperly and that the one-time test scores were not an accurate assessment of students’ learning and development. In addition, they cited negative effects on the curriculum, teaching and learning, and student and teacher motivation. The positive effects cited were much fewer in number and included the fact that the testing held students, educators, and parents accountable for their actions. Interestingly, teachers were not opposed to accountability, but rather, opposed the manner in which it was currently implemented. Only by understanding these positive and negative effects of the testing program can policymakers hope to improve upon it. To this end, we discuss several implications of these findings, including: limiting the use of test scores, changing the school grading criteria, using alternative assessments, modifying the curriculum, and taking steps to reduce teaching to the test

Rural Elementary Administrators’ Views of High-Stakes Testing

This study examines how rural elementary school administrators perceive the effects of high-stakes testing in comparison to suburban and urban elementary administrators. High-stakes testing had a greater impact, both positively and negatively, on rural administrators than on their counterparts in suburban and urban schools. Specifically, the positive effects were that rural administrators were more motivated by the testing program to do a better job, found the test results more useful in assessing teachers, and found the test results more useful in meeting the academic needs of students. The negative effects were that rural administrators felt more pressure than urban administrators to improve test scores and found their school rating to more negatively affect their ability to attract high quality teachers than administrators in suburban schools

DAP2D: A Two-Dimensional Device Simulation Tool for Silicon Bipolar Transistors

The purpose of this document is to serve as the final report for work performed for Delco Electronics for the period January 1, 1986 through May 15, 1989. A computer program, SCAP2D (Solar Cell Analysis Program in 2- Dimensions) has been successfully converted to enable the simulation of bipolar transistors, including Delco’s thin-epi transistor. This code will be referred to as DAP 2D (Device Analysis Program in 2-Dimensions). Complete source code of DAP 2D is being released to Delco Electronics. This report is organized as follows. Chapter 2 provides a review of the numerical device modeling and discusses code enhancements completed during the last contract year. Chapter 3 shows results obtained by simulating generic bipolar transistors, including polysilicon contacted emitter bipolar transistors. Chapter 4 shows results obtained from simulations of Delco’s thin-epi bipolar transistor. These chapters are intended to show the usefulness of DAP2D in analyzing and designing bipolar transistors. The appendices contain a user’s guide, as well as a complete simulation example

Polysilicon Emitter Fabrication and Modeling

The research proposed for 1986 was to develop the technology for fabricating, measuring, and computer modeling the polysilicon emitter bipolar transistor. Fabrication consisted of producing three types of bipolar transistors; a regular bipolar device to act as the control, a polysilicon contacted emitter transistor, and a polysilicon emitter directly on the base region with a very thin oxide at the interface. The proposed fabrication research concentrated on investigating a new method of fabricating polysilicon contacted emitter bipolar transistors. The new fabrication technique uses plasma etching of the emitter location on the base region and, without breaking vacuum, depositing amorphous silicon (a-Si) on the cleaned interface. The a-Si was then to be doped by ion-implantation and heated to 600-700 C ° to produce the polysilicon emitter contact. The controlled interface and the fine grained polysilicon should lead to more uniform and predictable betas for the polycontacted transistors. Both polysilicon contacted emitters and polysilicon emitters were to be investigated over a range of base doping. We proposed the modeling work in two directions: l) 2-D simulation so that small geometry transistors can be accurately modeled and 2) simulation of polysilicon contacted emitter transistors. Measurements on the devices described above will be used to develop a polysilicon model. The objective of this part of the project is to develop a numerical device simulator with predictive capability, i.e. one that can be used with confidence in place of actual device fabrication. The numerical device models will be provided to Delco and should find many applications in development and manufacturing. The fabrication highlights of the 1986 work were the design and fabrication of preliminary bipolar transistors and polysilicon emitters, the design and layout of the test wafer, and the fabrication and measurements on shallow arsenic doped emitter devices. There were 22 sets of fabrication runs made beyond the preliminary devices. The last results of these runs show that the shallow Arsenic emitter (0.05 /i) and the very narrow base width (0.1 y) control devices with metal emitter contact, have an average peak beta of about 75. Poly contacted emitter devices fabricated at the same time on the same wafer show a beta enhancement to 232, a factor of about 2.7 to 3.0 in the average peak beta. The polysilicon was deposited in a standard way in a LPCVD tube. We are presently fabricating polysilicon devices for studying the effects of the methods used in treating the surfaces before the poly is deposited and the way the poly is formed (amorphous PELPCYD)