Spin-Vibronic Intersystem Crossing and Molecular Packing Effects in Heavy Atom Free Organic Phosphor.

We present a detailed investigation into the excited state properties of a planar symmetric azatriangulenetrione, HTANGO, which has received significant interest due to its high solid-state phosphorescence quantum yield and therefore potential as an organic room temperature phosphorescent (ORTP) dye. Using a model linear vibronic coupling Hamiltonian in combination with quantum dynamics simulations, we observe that intersystem crossing (ISC) in HTANGO occurs with a rate of ∼10 s , comparable to benzophenone, an archetypal molecule for fast ISC in heavy metal free molecules. Our simulations demonstrate that the mechanism for fast ISC is associated with the high density of excited triplet states which lie in close proximity to the lowest singlet states, offering multiple channels into the triplet manifold facilitating rapid population transfer. Finally, to rationalize the solid-state emission properties, we use quantum chemistry to investigate the excited state surfaces of the HTANGO dimer, highlighting the influence and importance of the rotational alignment between the two HTANGO molecules in the solid state and how this contributes to high phosphorescence quantum yield

Influence of Vehicle Inspection Tests on Crashworthiness of School Bus in Nairobi County, Kenya

The vehicle structure, designs and materials on school bus body crashworthiness as regulated by different government agencies in bus body building firms was the topic under research study. In Kenya, thousands of vehicles are involved in vehicle collisions or crashes every year resulting in fatal accidents and severe injuries to the passengers. The specific objective was the influence of vehicle inspection testson crashworthiness of school bus in Nairobi City County. This study adopted Dym’s, Suh’s Axiomatic theory. The pragmatic paradigm and explanatory research design were used. The target population was 1500 respondents from bus body building firms and government regulatory institutions. The sample size was 315 respondents. Questionnaires,interview schedules and observation were data collection instruments. Expert judgment was used to establish validity ofthe questionnaires. Cronbach’s Alpha Coefficient was used to determine the reliability of the research instrument. The datacollected was analyzed using descriptive and inferential analysis with the aid of SPSS V22 software. The coefficient ofdetermination (R squared) of .206 showing that 20.6% of the variation in crashworthiness of a bus can be explained byvehicle inspection tests. There was a positive significant influence of vehicle inspection tests on crashworthiness of abus (β=0.396 and p <0.05). The study concluded that the vehicle inspection tests had a significant influence on thecrashworthiness of school bus. The management of school bus body construction companies need to conduct all the terminaltest needed before releasing the vehicle in order to enhance crashworthiness of a bus. The Transport authority shouldexamine and check the mandatory requirements and periodically amend them in accordance with the safety, engineering and ecological standardization

The Effect of The Scholarship Academy\u27s College Bound Initiative FAFSA Events on FAFSA Completion

The complexity, uncertainty, and timing of financial aid is a barrier not only to college access, but also to the effectiveness of financial aid. For over 15 years, The Scholarship Academy (TSA) has worked with families and high school students to address potential barriers in obtaining financial aid to matriculate at college. One of TSA’s initiatives, in partnership with the United Way of Greater Atlanta and Learn4Life, is the College Bound initiative. College Bound offers curated financial aid and college information to students, families, and school counselors. The program centers on FAFSA completion and college cost events for students. The events are followed by personalized counseling and coaching by TSA’s financial aid specialists. In this report, we evaluate the impact of TSA’s FAFSA initiative events in four metro Atlanta high schools during the 2021–22 school year. We focus on whether the events caused FAFSA completion rates to rise for participating high schools. Previous evidence on financial aid support suggests that informational interventions alone have limited impacts, while interventions that provide application support show more promising results. Based on descriptive results and the use of a more rigorous synthetic control method, we find that TSA’s FAFSA events had a positive effect on the cumulative average FAFSA completion rate of about 4.5 percentage points, although we cannot statistically rule out no effect. The impact of TSA’s FAFSA events varied substantially across the four participant schools: an event at Tri-Cities High Schools had a large positive impact on the cumulative FAFSA completion rate, and we find suggestive evidence of a smaller effect at Banneker High School, although we cannot statistically rule out that the impact was zero. Data limitations preclude us from reaching a definitive conclusion about the impacts at Lakeside and Creekside High Schools. Our results emphasize the importance of conducting follow-up activities after FAFSA events to maintain momentum, which is part of TSA’s current approach. The pattern of our findings for Tri-Cities and Banneker High Schools using weekly data supports the idea that sustained support and counseling is necessary to build on the success of the event(s) and maintain a higher cumulative FAFSA completion rate to the end of the FAFSA cycle.https://scholarworks.gsu.edu/gpl_reports/1044/thumbnail.jp

Electric vehicle drive-by-wire solution for distributed steering, braking and throttle control

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references.In this paper, we propose CityCarControl, a system to manage the steering, braking, and throttle of a new class of intra-city electric vehicles. These vehicles have a focus on extreme light-weight and a small parking footprint. In order to maximize maneuverability within a city environment, we show the feasibility of omnidirectional steering, and the integration of a folding chassis. Furthermore, we apply traditionally programming best-practice techniques to simplify the design of the control system. Specifically, we present the concept of a modular, fail-silent wheel-robot with a standardized API responsible for controlling steering, braking and throttle within the vehicle.by Thomas B. Brown.M.Eng

On-board demux/demod

To make satellite channels cost competitive with optical cables, the use of small, inexpensive earth stations with reduced antenna size and high powered amplifier (HPA) power will be needed. This will necessitate the use of high e.i.r.p. and gain-to-noise temperature ratio (G/T) multibeam satellites. For a multibeam satellite, onboard switching is required in order to maintain the needed connectivity between beams. This switching function can be realized by either an receive frequency (RF) or a baseband unit. The baseband switching approach has the additional advantage of decoupling the up-link and down-link, thus enabling rate and format conversion as well as improving the link performance. A baseband switching satellite requires the demultiplexing and demodulation of the up-link carriers before they can be switched to their assigned down-link beams. Principles of operation, design and implementation issues of such an onboard demultiplexer/demodulator (bulk demodulator) that was recently built at COMSAT Labs. are discussed

Production of tetra-methylpyrazine using engineered Corynebacterium glutamicum.

Corynebacterium glutamicum ATCC 13032 is an established and industrially-relevant microbial host that has been utilized for the expression of many desirable bioproducts. Tetra-methylpyrazine (TMP) is a naturally occurring alkylpyrazine with broad applications spanning fragrances to resins. We identified an engineered strain of C. glutamicum which produces 5 ​g/L TMP and separately, a strain which can co-produce both TMP and the biofuel compound isopentenol. Ionic liquids also stimulate TMP production in engineered strains. Using a fed batch-mode feeding strategy, ionic liquid stimulated strains produced 2.2 ​g/L of tetra-methylpyrazine. We show that feedback from a specific heterologous gene pathway on host physiology leads to acetoin accumulation and the production of TMP

Optothermal Stability of Large ULE and Zerodur Mirrors

Marshall Space Flight Center's (MSFC) X-ray and Cryogenic Test Facility (XRCF) has tested the optothermal stability of two low-CTE, large-aperture mirrors in a thermal vacuum chamber. The mirrors deformed from several causes such as: thermal gradients, thermal soaks, coefficient of thermal expansion (CTE) gradients, CTE mismatch, and stiction. This paper focuses on how the aforementioned conditions affected the surface figure of the large optics while in vacuum at temperatures ranging from 230 to 310 K (-43 to 37 C). The presented data, conclusions, and taxonomy are useful for designing mirrors and support structures for telescopes. The data is particularly useful for telescopes that require extreme dimensional stability or telescopes that operate at a temperature far from ambient