Business process reengineering : a study in theory and practice

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1994.Includes bibliographical references (leaves 108-109).by John S. Fleischli and J. Brinton Davis.M.S

Tailoring the optical properties of poly(3-hexylthiophene) by emulsion processing using polymeric macrosurfactants

Here we demonstrate that the use of macrosurfactants in the production of poly(3-hexylthiophene) (P3HT):water dispersion allows to drastically change the semiconductor's molecular aggregation, leading to pronounced H- or J-like behaviour depending on the macrosurfactant used and the conditions selected to produce the dispersions.</p

savingthewildplaces.org

Abstract Purpose The focus of this professional paper is the description of both collaborative and individual efforts to save a wild place, the Rocky Mountain Front (RMF) in Lewis and Clark National Forest in Montana. The purpose of doing that is to provide an example that others could use to save their own beloved wild place, wherever that might be. Methods The description includes the formation of the Friends of the Front in the late 1970s by Gene Sentz and Roy Jacobs. The group, now a coalition with three major environmental organizations, continues its activities in April 2012, the date of this paper’s completion. During this period of over 30 years, the participants in collaboration modeled a respectful, neighborly approach intended to build public support to prevent the use of the Front as an oil and gas industrial area. They accomplished the 1997 banning by forest supervisor Gloria Flora of any new oil and gas leases in the Lewis and Clark National Forest for the duration of that USFS Resource Plan. Then they obtained a buyout of existing leases, using a tax credit method through Congressional legislation, followed by the withdrawal of those forest lands from any future leasing. In a strenuous effort, hundreds of supporters of the RMF subsequently attended USFS meetings to shape the other part of forest planning, the Travel Plan. A Travel Plan balances motorized uses with other uses in the forest. Lastly, the Travel Plan was incorporated into a second federal law, introduced in Congress but yet to be passed in April 2012, that creates a new approach to forest management. By its terms it makes the Lewis and Clark National Forest a conservation easement of 208,000 acres, freezing the uses as they now exist under USFS management, permanently. It also sets up 67,000 acres of wilderness areas. While these monumental efforts continue, east of the RMF parcels of land owned by individuals removed their development rights from their lands using conservation easements, totaling 173,000 acres as of the summer of 2011. Conclusions The example described here works for a collaborative group effort to save wild places but it may require neighborly members. However, individual efforts can also achieve similar results, at least on private lands. This professional paper is published as a web site for easy dissemination and can be found at http://www.savingthewildplaces.org

The Effect of Interface Modification on the Properties of Organic Thin-Film Transistors

In organic thin-film transistors (OTFTs), the conducting channel is located near the interface between the organic semiconductor and the dielectric; this interface is crucial for transistor performance. The goal of this thesis is to study the effect of this interface, especially when it is modified either by surface treatments or self-assembled monolayers. For this purpose, OTFTs based on pentacene and doped silicon wafer gate electrode and gold top contacts are fabricated. The dielectric is either silicon oxide (SiO2) or polyimide (PI). The dielectric surface affects both the growth of the pentacene film on the top of it and the electric performance of the transistor. The pentacene film morphology is studied on treated and untreated SiO2 and PI surfaces by AFM and water contact angle measurements. Depending on the nature of the dielectric surface, traps or charge transfer centers are introduced which then affect the performance of the transistor. The transistor performance is determined by measuring the drain current as it is dependent upon the drain and gate voltage. The contributions of the channel and the contacts are separated by 4-probe measurements (at floating and non-floating gate). The transistors with untreated dielectrics are first characterized. The dependence on the channel length, the thickness and the morphology of the pentacene film is studied. The short channels (2 – 20 µm) are patterned by stencil masks; the long channels (100 – 600 µm) by steel masks. The results show that the transistors with a channel length of 20 µm and smaller are limited by the contacts, while the transistors with a channel length between 100 and 600 µm are dominated by the channel, and thus the traps and residual carriers in the channel. The pentacene film morphology has more influence on the contact resistance than on the channel behavior. To study the effect of the interface modifications, the transistor behavior should be dominated by the channel and the contact effects minimized; hence, long-channel transistors are used. The dielectric surfaces are treated by plasma or pH solutions prior to the pentacene deposition resulting in a variety of defects. The defects are distinguished by those which lead to a change in the film growth and those which affect the electric performance by introducing traps or charge transfer centers. To overcome the influence of the dielectric surface, the oxide dielectric is passivated by a self-assembled monolayer (SAM). The neutral SAM acts as a spacer between the dielectric and the pentacene film and thus enhances the transistor performance. The polar SAMs also introduce a dipole moment. A series of molecules with a similar length, but different end groups, are used to investigate the effect of the dipole moment. The main result of this study is that the nature and the quality of the gate and the contact interfaces are often more important for the performance of the transistors than the thin film morphology

Lung macrophage scavenger receptor SR-A6 (MARCO) is an adenovirus type-specific virus entry receptor

<div><p>Macrophages are a diverse group of phagocytic cells acting in host protection against stress, injury, and pathogens. Here, we show that the scavenger receptor SR-A6 is an entry receptor for human adenoviruses in murine alveolar macrophage-like MPI cells, and important for production of type I interferon. Scavenger receptors contribute to the clearance of endogenous proteins, lipoproteins and pathogens. Knockout of SR-A6 in MPI cells, anti-SR-A6 antibody or the soluble extracellular SR-A6 domain reduced adenovirus type-C5 (HAdV-C5) binding and transduction. Expression of murine SR-A6, and to a lower extent human SR-A6 boosted virion binding to human cells and transduction. Virion clustering by soluble SR-A6 and proximity localization with SR-A6 on MPI cells suggested direct adenovirus interaction with SR-A6. Deletion of the negatively charged hypervariable region 1 (HVR1) of hexon reduced HAdV-C5 binding and transduction, implying that the viral ligand for SR-A6 is hexon. SR-A6 facilitated macrophage entry of HAdV-B35 and HAdV-D26, two important vectors for transduction of hematopoietic cells and human vaccination. The study highlights the importance of scavenger receptors in innate immunity against human viruses.</p></div

Effects of Classroom Composition on the Development of Antisocial Behavior in Lower Secondary School

Early adolescence is a critical period during which classroom composition may affect behavioral development. This study investigated whether classmates' levels of aggression and delinquency influenced individual behavior during the first year of secondary school. At this point, students had just transitioned to a new classroom peer environment. A short-term longitudinal design with four measurement points distributed across the school year was applied. Data were collected from the anonymous self-reports of 825 7th graders. Longitudinal negative binomial multilevel analyses revealed that classmates’ antisocial behavior influenced pupils’ behavioral development (other peer influences were controlled). Furthermore, classroom behavioral heterogeneity did not moderate this effect