Photophysics of Single Rhodamine Dye Molecules on TiO2 Substrates

Dye-sensitized solar cells (DSSCs) comprised of sensitizers within a TiO2 semiconductor matrix are promising photovoltaics that use electron transfer (ET) to convert photons into current. Improvements in DSSC efficiency require fundamental understanding of the distribution of forward and back ET dynamics at the dye-semiconductor interface, which ensemble-averaged experiments are incapable of observing. In this study, the distributions of ET dynamics in dye-sensitized TiO2 systems are probed using single-molecule fluorescence (SMF) microscopy. The time-dependent emission (i.e., blinking dynamics) of rhodamine 6G (R6G), rhodamine B (RB), and 5-carboxy-x-rhodamine (5-ROX) sensitized colloidal anatase TiO2 films are quantified by constructing histograms of emissive (“on”) and non-emissive (“off”) events. Robust statistical analysis reveals that the off-time distributions for molecules on TiO2 are not consistent with the power-law hypothesis and are instead well represented by log-normal distributions. These ET data are consistent with the Albery model of a Gaussian distribution of activation energies, where the power-law and log-normal distribution fit parameters are sensitive to experimental time resolution and cannot be analyzed as absolute values. Relative comparison of the fit parameters of R6G, RB, and 5-ROX ET distributions on colloidal TiO2 provides insight into the effect of sensitizer structure on the photophysical system. Notably, log-normally distributed off times produce a larger scaling parameter μ for 5-ROX than for R6G or RB, suggesting the dye binds more strongly to TiO2 than R6G or RB and produces slower back electron transfer (BET) rates due to increased electron delocalization. The on-time distributions for rhodamine dyes on TiO2 are fit by power laws, but they are only operative for long emissive durations comprising less than 15% of the photophysical data. Changes in fluorescent spot density on false-colored images of R6G on bare glass, colloidal anatase TiO2, and single-crystal rutile TiO2 illustrate the impact of substrate on ET dynamics, but single-molecule studies of rhodamine molecules on single-crystal rutile could not be completed due to extremely efficient ET. Future investigations will apply single-molecule methodologies with picosecond resolution to dye-semiconductor systems

Intersectionality

Introduction Before starting this reflective essay, I acknowledge that the work of feminist anthropologists is not timeless and covers a vast range of ideas such that I do not assert that my learning condensed here is in any way exhaustive. The poem I wrote below speaks to the unevenness of inequality, focusing on intersectionality, multiple axes of gendered inequality, and resistance through corporeal practices

Interview by Wong Sau Lin Natalie

I write this summary after the interview, now I would like to highlight some interesting aspects of the interview. Ling is twenty-three years old. She has two younger brothers. They have a close relationship with each other. She was born in China. Her mother has immigrated to Hong Kong when she was two years old. Then she also immigrated to Hong Kong when she was nine years old. In China, her grandparent looked after her. They were farmers; she likes to talk with them. She thinks that they affect her view of life. She learns positive, optimistic and hard work from them. When she was young, sometimes she missed her parent because she can\u27t live with them. That\u27s why when she come to Hong Kong, she love and respect to her parent. She point out aht when she was young, her mother was a housewife as she needed to look after her younger brothers and his father was a factory worker, therefore, the economic condition was not good of her family. So, her parent couldn\u27t satisfy her material desires. But she never made any grievances on them because she knew their parent\u27s difficulties. In fact, she graduated in Form Five, then tried to find job to share the burden with her parent. She also shares happy and bitter experience to me. Bitter experience is that she lived in hospital for two weeks when she was fourteen years old. The reason was that she needed to do surgery to cut the tumour which growth on her hip. She never forgets the painful after the operation. She also felt love and concern from her parents during the period of the hospital. On the other hand, happy experience happened in temporary housing. She has learned many skills such as leadership, creativity and communication when she was a voluntary in YMCA. More importantly, she can help the needy. Also, she met a lot of friends when she lived in temporary hosing, they teach her to do homework. Up to know, they can keep good and close relationship with each other. No matter how the friends treating her, her family is the most important for her in the world

Thermodynamics in Mono and Biphasic Continuum Mechanics

This chapter applies the laws of thermodynamics to problems in continuum mechanics. Initially these are applied to a monophasic medium. The case of a biphasic porous medium is then treated with the aim of illustrating how a framework may be established for capturing possible couplings in the pertinent constitutive relationships. This approach is founded on the two laws of Thermodynamics. The first law expresses the conservation of energy when considering all possible forms while the second law postulates that the quality of energy must inevitably deteriorate in relation to its transformability into efficient mechanical work

Black Box Adversarial Prompting for Foundation Models

Prompting interfaces allow users to quickly adjust the output of generative models in both vision and language. However, small changes and design choices in the prompt can lead to significant differences in the output. In this work, we develop a black-box framework for generating adversarial prompts for unstructured image and text generation. These prompts, which can be standalone or prepended to benign prompts, induce specific behaviors into the generative process, such as generating images of a particular object or generating high perplexity text

Educational Impact on Therapists’ Knowledge, Beliefs, and Actions: A Pilot Study

ABSTRACT Purpose: Collaborative goal setting has been shown to be an effective way to promote client engagement leading to improved outcomes; however, healthcare professionals face challenges when implementing collaborative goal setting into their clinical practice. The purpose of this study was to evaluate the effectiveness of educational workshops to 1) increase a therapist’s knowledge of motivational interviewing and action planning, 2) promote collaboration between therapists and their patients/clients, 3) promote collaboration between therapists and their interdisciplinary team and 4) increase the ease of implementation of motivational interviewing and action planning skills into a therapist’s clinical practice. Method: A mixed-methods design was utilized. Occupational therapists and physical therapists were recruited via email to participate. Data were collected via online surveys at three different times (before the first educational workshop, after the second workshop, and three months after the second workshop) consisting of quantitative related survey questions assessing the participants’ knowledge, beliefs, actions, and perceived self-efficacy related to motivational interviewing and action planning and qualitative questions focused on typical goal development processes, level of collaboration and challenges associated with developing goals with clients and interdisciplinary team members and anticipated/resultant impact and meaning of participation in the educational workshops. Results: The sample included 19 participants. Quantitative data demonstrated a statistically significant increase in self-scoring related to knowledge, beliefs, and actions when comparing all the pre-education to the post-education scores, except for one (collaboration with interdisciplinary team members). A follow-up analysis on this criterion demonstrated no statistically significant changes over the three-month period, potentially indicative of retention of the material covered. The qualitative data provided further insight into the challenges faced by participants and the perceived benefits of participating in the educational workshops. Conclusion: The educational workshops appeared to be effective in addressing some of the barriers to collaborative goal setting (e.g. lack of time, knowledge/skills, appropriate patients, concern for duplication of services) found in the literature, most notably providing the participants with the knowledge and skills needed, which is the first step when implementing collaborative goal setting into clinical practice. Further research in this area is recommended

Urban-biased structural change

Using firm-level data from France, we document that the shift of economic activity from manufacturing to services over the last few decades has been urban-biased: structural change has been more pronounced in areas with higher population density. This bias can be accounted for by the location choices of large services firms that sort into big cities and large manufacturing firms that increasingly locate in suburban and rural areas. Motivated by these findings, we estimate a structural model of city formation with heterogeneous firms and international trade. We find that agglomeration economies have strengthened for services but weakened for manufacturing. This divergence is a key driver of the urban bias, but it dampens aggregate structural change. Rising manufacturing productivity and falling international trade costs further contribute to the growth of large services firms in the densest urban areas, boosting services productivity and services exports, but also land prices

Leicester Public Schools Information and Data Portal: Research and Recommendations

The purpose of this project is to develop a strategy for the creation of a multifaceted portal to help with the organization and dissemination of information about the Leicester public school district. The functionality of this portal is to provide comparative financial, demographic, and academic data to other relative school districts in the area, both for the parents’ and for the city’s reference. It will be an examination into the best practices for creating a portal, both technological and aesthetic recommendations, as well as research into the value the publication of this data would provide for the parents of current and prospective students as well as the district and the greater town. As for a basic overview, this project will examine four comparable Massachusetts districts’ data, Milbury, Abington, Avon, and Uxbridge, and construct some visual representations of comparable statistics. The key areas to be compared are: for financial, the total budget, per pupil expenditure, and Chapter 70 money; for academic, MCAS percentage proficient and advanced, SAT scores, and number of AP tests taken; and for demographic, graduation rate, attendance rate, and dropout rate. The secondary part of the project is a best practices recommendation which will be comprised of two parts: technological tools and aesthetics/usability, which will be supported with a discussion about the value this type of portal would have for a school district

Strategies for peri-urbanism in Dongguan

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 90-91).Thirty years of Open Door Policy has brought about a series of urban restructuring of cities in the Pearl River Delta of China. The Peri Urban fabric of the these cities are formed as a result of complex orchestration of urban processes. In particular, rural hinterland are increasing being exploited as a vacuum for industrial expansion. The mono-functional spread of industrial estate has a limited life span, it is vulnerable to economic downturn, and undermine the possibility of small scale farming, an economic practice that is proved still relevant given the fact that rural and urban citizenship still maintain a clear distinction. This thesis proposes a new model of industrial facility that addresses the conflict of rural land resources rapid industrialization. It provides the necessary infrastructure for a constantly changing rural urban economic model. It is invested in creating an urbanity out of this unique economy without necessarily abiding to the conventional zoning model. Architecturally the project transforms the generic conditions of each constituent production program in response to a typological reconfiguration.by Chit Ying Natalie Wong.M.Arch

Beyond NIMBY: The Emergence of Environmental Activism and Policy Change in Two Chinese Cities

The present research article focuses on public participation in the environmental policy-making process in post-Mao China. It is a well-known fact that public administration in socialist China is highly centralised, and that public policies are initiated at the center and then locally administered under the one-party rule. In this monist political system, main stakeholders in the policy process are mainly Chinese Communist Party cadres, together with the ‘authorised’ groups of societies; so far participation from autonomous interest groups and society has been limited at best. In general, the ‘western model’ of civil society, which is characterised by a plurality of interest groups participating in public policymaking, implementation and evaluation, has – so far – been absent in China. This study aims to use environmental protection as a platform to examine the transformations that have been taking place in the environmental policy process and use it as a piece of references to revisit the current academic literature on China. Specifically this article will compare two anti-incinerator protests in Guangzhou (Canton) and Beijing, to illustrate the dynamics surrounding the emergence of public participation in China’s environmental policy process. This study plans to analyse why Guangzhou and Beijing Municipal governments have had different responses and attitudes to address citizens’ grievances. Furthermore, the research will dwell on the establishment up of a Public Consultative and Supervision Committee for Urban Waste Management in Guangzhou City, a public consultative mechanism on waste management, which certainly represents a major novelty and a breakthrough for the policy making process of China. This research project demonstrates how policy adjustment is not determined solely by protests’ outcomes but is also greatly affected by the response of local governments and the development of civil society. Consequently, the discussion is expected to give a new interpretation on environmental management of China