Monte Carlo simulation of kilovolt electron transport in solids

A Monte Carlo procedure to simulate the penetration and energy loss of low¿energy electron beams through solids is presented. Elastic collisions are described by using the method of partial waves for the screened Coulomb field of the nucleus. The atomic charge density is approximated by an analytical expression with parameters determined from the Dirac¿Hartree¿Fock¿Slater self¿consistent density obtained under Wigner¿Seitz boundary conditions in order to account for solid¿state effects; exchange effects are also accounted for by an energy¿dependent local correction. Elastic differential cross sections are then easily computed by combining the WKB and Born approximations to evaluate the phase shifts. Inelastic collisions are treated on the basis of a generalized oscillator strength model which gives inelastic mean free paths and stopping powers in good agreement with experimental data. This scattering model is accurate in the energy range from a few hundred eV up to about 50 keV. The reliability of the simulation method is analyzed by comparing simulation results and experimental data from backscattering and transmission measurements.

Ellipsometric study of a-Si:H thin films deposited by square wave modulated rf glow discharge

Thin films of hydrogenated amorphous silicon (a‐Si:H), deposited by square wave modulated (SQWM) rf silane discharges, have been studied through spectroscopic and real time phase modulated ellipsometry. The SQMW films obtained at low mean rf power density (19 mW/cm2) have shown smaller surface roughness than those obtained in standard continuous wave (cw) rf discharges. At higher rf powers (≥56 mW/cm2), different behaviors depending on the modulating frequency have been observed. On the one hand, at low modulating frequencies (<40 Hz), the SQWM films have shown a significant increase of porosity and surface roughness as compared to cw samples. On the other, at higher modulating frequencies, the material density and roughness have been found to be similar in SQWM and cw films. Furthermore, the deposition rate of the films show more pronounced increases with the modulating frequency as the rf power is increased. Experimental results are discussed in terms of plasma negative charged species which can be relatively abundant in high rf power discharges and cause significant effects on the deposited layers through polymers, clusters, and powder formation.

Electrical and optical properties of Zn-In-Sn-O transparent conducting thin films

Indium tin oxide (ITO) is one of the widely used transparent conductive oxides (TCO) for application as transparent electrode in thin film silicon solar cells or thin film transistors owing to its low resistivity and high transparency. Nevertheless, indium is a scarce and expensive element and ITO films require high deposition temperature to achieve good electrical and optical properties. On the other hand, although not competing as ITO, doped Zinc Oxide (ZnO) is a promising and cheaper alternative. Therefore, our strategy has been to deposit ITO and ZnO multicomponent thin films at room temperature by radiofrequency (RF) magnetron co-sputtering in order to achieve TCOs with reduced indium content. Thin films of the quaternary system Zn-In-Sn-O (ZITO) with improved electrical and optical properties have been achieved. The samples were deposited by applying different RF powers to ZnO target while keeping a constant RF power to ITO target. This led to ZITO films with zinc content ratio varying between 0 and 67%. The optical, electrical and morphological properties have been thoroughly studied. The film composition was analysed by X-ray Photoelectron Spectroscopy. The films with 17% zinc content ratio showed the lowest resistivity (6.6 × 10 - 4 Ω cm) and the highest transmittance (above 80% in the visible range). Though X-ray Diffraction studies showed amorphous nature for the films, using High Resolution Transmission Electron Microscopy we found that the microstructure of the films consisted of nanometric crystals embedded in a compact amorphous matrix. The effect of post deposition annealing on the films in both reducing and oxidizing atmospheres were studied. The changes were found to strongly depend on the zinc content ratio in the films.

Insight into oversight : how information commissioners contribute to the achievement of access-to-information policy objectives

This thesis examines how oversight bodies, as part of an ATI policy, contribute to the achievement of the policy's objectives. The aim of the thesis is to see how oversight bodies and the work they do affects the implementation of their respective ATI policies and thereby contributes to the objectives of those policies using a comparative case study approach. The thesis investigates how federal/central government level information commissioners in four jurisdictions - Germany, India, Scotland, and Switzerland - enforce their respective ATI policies, which tasks they carry out in addition to their enforcement duties, the challenges they face in their work and the ways they overcome these. Qualitative data were gathered from primary and secondary documents as well as in 37 semi-structured interviews with staff of the commissioners' offices, administrative officials whose job entails complying with ATI, people who have made ATI requests and appealed to their respective oversight body, and external experts who have studied ATI implementation in their particular jurisdiction. The thesis finds that while the aspect of an oversight body's formal independence that has the greatest impact on its work is resource control and that although the powers granted by law set the framework for ensuring that the administration is properly complying with the policy, the commissioner's leadership style - a component of informal independence - has more influence than formal attributes of independence in setting out how resources are obtained and used as well as how staff set priorities and utilize the powers they are granted by law. The conclusion, therefore, is that an ATI oversight body's ability to contribute to the achievement of the policy's objectives is a function of three main factors: a. commissioner's leadership style; b. adequacy of resources and degree of control the organization has over them; c. powers and the exercise of discretion in using them. In effect, the thesis argues that it is difficult to pinpoint the value of the formal powers set out for the oversight body in the ATI law, and that their decisions on whether and how to use them are more important than the presumed strength of the powers. It also claims that the choices made by the commissioners and their staff regarding priorities and use of powers are determined to a large extent by the adequacy of resources and the degree of control the organization has over those resources. In turn, how the head of the organization leads and manages the oversight body is crucial to both the adequacy of the organization's resources and the decisions made about the use of powers. Together, these three factors have a significant impact on the body's effectiveness in contributing to ATI objectives.

Strong coupling solution to Schrödinger Equation: the mixing of states

In this paper we give some ideas that can be useful to solve Schrödinger equations in the case when the Hamiltonian contains a large term. We obtain an expansion of the solution in reciprocal powers of the large coupling constant. The procedure followed consists in considering that the small part of the Hamiltonian engenders a motion adiabatic to the motion generated by the large part of the same.

The rewards of cooperation: The effects of membership in European regulatory networks

Networks famously epitomize the shift from 'government' to 'governance' as governing structures for exercising control and coordination besides hierarchies and markets. Their distinctive features are their horizontality, the interdependence among member actors and an interactive decision-making style. Networks are expected to increase the problem-solving capacity of political systems in a context of growing social complexity, where political authority is increasingly fragmented across territorial and functional levels. However, very little attention has been given so far to another crucial implication of network governance - that is, the effects of networks on their members. To explore this important question, this article examines the effects of membership in European regulatory networks on two crucial attributes of member agencies, which are in charge of regulating finance, energy, telecommunications and competition: organisational growth and their regulatory powers. Panel analysis applied to data on 118 agencies during a ten-year period and semi-structured interviews provide mixed support regarding the expectation of organisational growth while strongly confirming the positive effect of networks on the increase of the regulatory powers attributed to member agencies.

El secreto de Vera Drake (2004) y Las Normas de la Casa de la Sidra (1999): el aborto en el cine y su utilización en la docencia

El Secreto de Vera Drake (2004) de Mike Leigh y de Las Normas de la Casa de la Sidra (1999) de Lasse Hallström presentan la interrupción voluntaria del embarazo y las circunstancias que la rodean en un total de diez abortos y un parto. El Secreto de Vera Drake nos muestra a una mujer de clase media-baja que"ayuda a chicas jóvenes" a poner fin a embarazos no deseados sin aceptar dinero a cambio. Su secreto se desvelará cuando una de las jóvenes a la que practicó un aborto sufre complicaciones y es condenada. Las Normas de la Casa de la Sidra presenta la historia de Homer Wells, un joven que nace y crece en un orfanato donde su responsable, el Dr. Larch, le enseña a asistir partos y a practicar abortos. Un día Homer siente la necesidad de volar libre fuera del orfanato e inicia un viaje que le acercará a otras realidades que le llevarán a reconsiderar su postura en contra del aborto. Ambas películas pueden ser un material útil para estudiar aspectos clínicos, éticos y sociodemográficos del aborto inducido en las enseñanzas de medicina, enfermería y matrona.

El secreto de Vera Drake (2004) y Las Normas de la Casa de la Sidra (1999): el aborto en el cine y su utilización en la docencia

El Secreto de Vera Drake (2004) de Mike Leigh y de Las Normas de la Casa de la Sidra (1999) de Lasse Hallström presentan la interrupción voluntaria del embarazo y las circunstancias que la rodean en un total de diez abortos y un parto. El Secreto de Vera Drake nos muestra a una mujer de clase media-baja que"ayuda a chicas jóvenes" a poner fin a embarazos no deseados sin aceptar dinero a cambio. Su secreto se desvelará cuando una de las jóvenes a la que practicó un aborto sufre complicaciones y es condenada. Las Normas de la Casa de la Sidra presenta la historia de Homer Wells, un joven que nace y crece en un orfanato donde su responsable, el Dr. Larch, le enseña a asistir partos y a practicar abortos. Un día Homer siente la necesidad de volar libre fuera del orfanato e inicia un viaje que le acercará a otras realidades que le llevarán a reconsiderar su postura en contra del aborto. Ambas películas pueden ser un material útil para estudiar aspectos clínicos, éticos y sociodemográficos del aborto inducido en las enseñanzas de medicina, enfermería y matrona.

The co-evolution of social institutions, demography, and large-scale human cooperation.

Human cooperation is typically coordinated by institutions, which determine the outcome structure of the social interactions individuals engage in. Explaining the Neolithic transition from small- to large-scale societies involves understanding how these institutions co-evolve with demography. We study this using a demographically explicit model of institution formation in a patch-structured population. Each patch supports both social and asocial niches. Social individuals create an institution, at a cost to themselves, by negotiating how much of the costly public good provided by cooperators is invested into sanctioning defectors. The remainder of their public good is invested in technology that increases carrying capacity, such as irrigation systems. We show that social individuals can invade a population of asocials, and form institutions that support high levels of cooperation. We then demonstrate conditions where the co-evolution of cooperation, institutions, and demographic carrying capacity creates a transition from small- to large-scale social groups.

Local Public Health Guidebook, September 2011

The local board of health is described in law in Iowa Code Chapter 137. It is described in rule in Iowa Administrative Code chapter 641.77. Law and rule define the structure, powers, and duties of the local board of health. The following information is a summation of the two. LOCAL BOARD OF HEALTH JURISDICTION AND APPOINTMENT: There are three types of local boards of health. 1. City (has to have been in existence before July 1, 2010) 2. County 3. District • City boards of health have jurisdiction over public health matters within the city. City board members are appointed by the city council. • County boards of health have jurisdiction over public health matters within the county. County board members are appointed by the county board of supervisors. • District boards of health have jurisdiction over public health matters within the district. District board of health members are appointed by the county boards of supervisors from the counties represented by the district.