Chemical kinetics and photochemical data for use in stratospheric modeling: Evaluation number 5

Sets of rate constants and photochemical cross sections compiled which were evaluated. The primary application of the data is in the modeling of stratospheric processes on the ozone layer and its possible perturbation by anthropogenic and natural phenomena are emphasized

Chemistry of the CO dimer at low temperatures

Researchers conducted a series of experiments on the chlorine-catalyzed photodecomposition of O sub 3 both in the gas and in inert solvents such as CF sub 4 and CO sub 2 in the temperature range about 190 to 225 K. The liquid medium was chosen in order to minimize possible surface loss of long-lived ClO dimer, and to aid in the stabilization of transient excited intermediates. The mechanism of dimer formation was as follows: (1) Cl sub 2 + hv yields Cl + Cl; (2) Cl + O sub 3 yields ClO + O sub 2; (3) ClO + ClO yields Cl sub 2 O sub 2. The experiments were done in cooled low temperature cells, with irradiation from an Osram high pressure mercury arc, filtered to remove radiation below 325 nm. Spectral analysis was by means of a Cary Model 2200 UV spectrometer. The principal objectives were: (1) to determine the lifetime of the dimer as a function of temperature; (2) to observe spectral changes in the mixtures which could be attributed to dimer or related products; and (3) to observe chemical or photochemical reactions of the dimer

Child distress during immunization: The influence of child and parent individual difference variables

Routine childhood immunization injections result child distress, which may have lasting negative effects on children, parents, and staff, and impact adherence to schedules of immunization. Aims of the current study were to (a) examine the role of child and parent individual difference variables in relation to child immunization distress, and (b) determine whether child distress predicts future immunization schedule adherence.;Parents of 50 children (aged 12--18 months) attending a visit to a pediatric medical clinic for purposes of immunization completed measures of child temperament, parent psychopathology, immunization beliefs, and prior medical distress of the child. Child distress during the immunization injection was measured via parent and nurse ratings and a behavior observational scale. Adherence to the immunization schedule was assessed via the Immunization Delivery Effectiveness Score (IDEA) and the families\u27 attendance at a follow-up immunization appointment.;Positive correlations were observed between child distress and prior medical distress of the child, difficult child temperament, and parent psychopathology. Negative correlations were found between child distress and child age and parent immunization beliefs. Boys exhibited more distress than girls. Child age and parent psychopathology each made unique contributions in explaining the variance in child distress. An interaction was observed between (a) prior medical experience and immunization adherence, and (b) health care attitudes and immunization adherence in the relation to child distress. Magnitude of child distress was greatest among children (a) with prior negative medical experiences and poorer adherence to schedules of immunization, and (b) with parents possessing negative immunization beliefs and poorer adherence to schedules of immunization. Child distress did not predict attendance at a subsequent clinic visit for purposes of immunization.;Several child and parent factors are related to various measures of child distress employed in this study. Results offer partial support for extant literatures (i.e., relations among immunization distress and age, gender, negative prior medical experiences, healthcare attitudes), and expand on a dearth in literature (i.e., relation between child distress and parent psychopathology). Findings may assist clinicians in identifying children at greatest risk for experiencing significant distress reactions during immunizations and providing training in effective interventions designed to minimize pain

Development of a two axis motion simulation system for thermal/vacuum satellite testing

A two-axis motion simulation system for thermal vacuum testing of large satellites in a space simulation chamber was developed. Satellites as large as 3000 kilograms with a 4-meter diameter and a 5-meter length can be tested. This motion simulator (MS) incorporates several unique features which result in a less complicated design with improved performance when compared to previous satellite motion simulators. The design of the simulator is discussed in detail

An assessment of an F2 or N2O4 atmospheric injection from an aborted space shuttle mission

Assuming a linear relationship between the stratosphere loading of NOx and the magnitude of the ozone perturbation, the change in ozone expected to result from space shuttle ejection of N2O4 was calculated based on the ozone change that is predicted for the (much greater) NOx input that would accompany large-scale operations of SSTs. Stratospheric fluorine reactions were critically reviewed to evaluate the magnitude of fluorine induced ozone destruction relative to the reduction that would be caused by addition of an equal amount of chlorine. The predicted effect on stratospheric ozone is vanishingly small

INSIDERS' VOICES: A PHENOMENOLOGICAL STUDY OF INFORMAL TEACHER LEADERSHIP FROM THE PERSPECTIVE OF THOSE WHO CHOOSE TO LEAD

INSIDERS' VOICES: A PHENOMENOLOGICAL STUDY OF INFORMAL TEACHER LEADERSHIP FROM THE PERSPECTIVE OF THOSE WHO CHOOSE TO LEAD Constance F. DeMore Palmer, EdD.University of Pittsburgh, 2011This qualitative study examined the phenomenon of informal teacher leadership from the perspective of teachers who willingly, and for no compensation, choose to accept responsibilities beyond those specified by the terms of their contractual agreements. The study was conducted to discover factors - namely, elements of school culture - that motivate informal teacher leaders to accept responsibilities beyond those required. By learning why some teachers choose to lead by engaging in extra-role behaviors (Organ, 1990) while others do not, I am able to propose ways that school administrators might encourage informal teacher leadership necessary for school improvement.Research was situated in one small and one medium sized suburban middle school in Pennsylvania. During semi-structured interviews with principals, informal teacher leaders, and non-leading teachers, respondents described the phenomenon of informal teacher leadership according to his or her: (a) perception of self; (b) understanding of role; (c) prior experiences; (d) administrator's actions; (e) community's needs; and (f) school's culture.As a result of this study, I discovered that "informal teacher leadership" cannot be defined universally because the term means something unique and personal to every leader. Although informal teacher leaders often remain self-motivated to assume extra-role responsibilities (Organ, 1990), administrators' actions, school culture, relationships amongivcolleagues, and the perceived physical or emotional needs of students also influence whether some teachers will extend themselves beyond the terms of their contracts.To promote and sustain this abstract phenomenon, administrators might help teachers recognize their respective and often undefined roles - perhaps according to four domains of organizational citizenship behaviors (Oplatka, 2006). Administrators also might encourage the phenomenon by fostering a culture conducive to the emergence of informal teacher leaders. According to respondents, administrators can create this type of culture by: (a) cultivating, supporting, and praising informal leadership behaviors; (b) squelching behaviors that hinder informal teacher leadership, and particularly, incidences of relational bullying among colleagues - a significant impediment to informal teacher leadership; and (c) familiarizing teachers with the needs of the surrounding community

The Fabrication and Integration of a 15 MHz Array Within a Biopsy Needle

It is proposed that integrating ultrasound transducer arrays at the tip of tools such as biopsy needles could enable valuable, real-time image feedback during interventional procedures. High-resolution ultrasound imaging has the potential to aid navigation of interventional tools, and to assist diagnosis or treatment via in-vivo tissue characterisation in the breast, amongst many other applications. In order to produce miniature transducer arrays incorporated within biopsy needle-sized packages (2-5 mm diameter), the challenges in micromachining and handling transducer materials at this scale must be overcome. This paper presents fabrication processes used in the micromachining of a 16 element 15 MHz PIN-PMN-PT piezocrystal-polymer composite array and its integration into an 11 G breast biopsy needle. Particular emphasis is given to the manufacturing of the 1-3 dice-and-fill piezocrystal composite, and establishing electrical interconnects. Characterisation measurements have demonstrated operation of each of the 16 elements within the needle case

Absorption cross sections of the ClO dimer

The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%

Temperature-Dependent Rate Constants and Substituent Effects for the Reactions of Hydroxyl Radicals With Three Partially Fluorinated Ethers

Rate constants and temperature dependencies for the reactions of OH with CF3OCH3 (HFOC-143a), CF2HOCF2H (HFOC-134), and CF3OCF2H (HFOC-125) were studied using a relative rate technique in the temperature range 298-393 K. The following absolute rate constants were derived: HFOC-143a, 1.9E-12 exp(-1555/T); HFOC-134, 1.9E-12 exp(-2006/T); HFOC-125, 4.7E-13 exp(-2095/T). Units are cm(exp 3)molecule(exp -1) s(exp -1). Substituent effects on OH abstraction rate constants are discussed, and it is shown that the CF3O group has an effect on the OH rate constants similar to that of a fluorine atom. The effects are related to changes in the C-H bond energies of the reactants (and thereby the activation energies) rather than changes in the preexponential factors. On the basis of a correlation of rate constants with bond energies, the respective D(C-H) bond strengths in the three ethers are found to be 102, 104, and 106 kcal/mol, with an uncertainty of about 1 kcal/mol

Application-Program-Installer Builder

A computer program builds application programming interfaces (APIs) and related software components for installing and uninstalling application programs in any of a variety of computers and operating systems that support the Java programming language in its binary form. This program is partly similar in function to commercial (e.g., Install-Shield) software. This program is intended to enable satisfaction of a quasi-industry-standard set of requirements for a set of APIs that would enable such installation and uninstallation and that would avoid the pitfalls that are commonly encountered during installation of software. The requirements include the following: 1) Properly detecting prerequisites to an application program before performing the installation; 2) Properly registering component requirements; 3) Correctly measuring the required hard-disk space, including accounting for prerequisite components that have already been installed; and 4) Correctly uninstalling an application program. Correct uninstallation includes (1) detecting whether any component of the program to be removed is required by another program, (2) not removing that component, and (3) deleting references to requirements of the to-be-removed program for components of other programs so that those components can be properly removed at a later time