Time-resolved Microwave Conductivity. Part 2.-Quantum-sized TiO_2 and the Effect of Adsorbates and Light Intensity on Charge-carrier Dynamics

Charge-carrier recombination dynamics after a pulsed laser excitation are investigated by time-resolved microwave conductivity (TRMC) for quantum-sized (Q-) TiO_2 and P25, a bulk-phase TiO_2. Adsorbed scavengers such as HNO_3, HC, HCIO_4, isopropyl alcohol, trans-decalin, tetranitromethane, and methyl viologen dichloride result in different charge-carrier recombination dynamics for Q-TiO_2 and P25. The differences include a current doubling with isopropyl alcohol for which electron injection into Q-TiO_2 is much slower than into P25 and relaxation of the selection rules of an indirect-bandgap semiconductor due to size quantization. However, the faster interfacial charge transfer predicted for Q-TiO_2 due to a 0. 2 eV gain in redox overpotentials is not observed. The effect of light intensity is also investigated. Above a critical injection level, fast recombination channels are opened, which may be a major factor resulting in the dependence of the steady-state photolysis quantum yields on l^(–1/2). The fast recombination channels are opened at lower injection levels for P25 than for Q-TiO_2, and a model incorporating the heterogeneity of surface-hole traps is presented

Youth Profiles of Program Quality Perceptions and Their Associations with Social Competence

Many youth development programs (YDPs) aim to help young people improve their social competence, defined as the ability to navigate social situations effectively. Researchers have documented that the quality of YDPs is associated with youth outcomes, including social competence. There are multiple aspects of program quality (e.g., fun, sense of belonging). Most previous research has utilized a variable-centered approach to explore how individual components of program quality are associated with young people’s social competence. However, program participants do not experience individual aspects of program quality in isolation. The current study used person-centered analyses to account for young people’s experiences of multiple components of program quality. Using national data from 166,640 participants of Boys & Girls Clubs of America (BGCA), this study identified profiles of program participants based on their perceptions of seven indicators of program quality (i.e., fun, sense of belonging, adult caring relationships, physical safety, emotional safety, staff expectations, staff recognition). Youth (9-12 years old) and teens (13-18 years old) were classified into five profiles. Four of the profiles included consistent ratings for all indicators of program quality: Above Average, Below Average, Very Below Average, and Negative. Approximately 70% of youth and teens were classified into the Above Average profile. The fifth profile was small (fewer than 2% of participants) and included above average ratings for all indicators except Belonging and Emotional Safety. Young people in the Above Average and Low Belonging and Emotional Safety profiles reported higher levels of each social competence outcome variable (i.e., Teamwork, Leadership, Conflict Resolution, Concern for Others) than young people in the three other profiles. When comparing levels of social competence in 2018 controlling for baseline levels in 2017, young people in the Above Average profile and the Low Belonging and Emotional Safety profile reported higher social competence than young people in the other profiles for 21 of the 48 comparisons after Bonferroni correction. Given that program quality is associated with social competence, it is important for YDPs to prioritize improving quality, especially for young people who have low perceptions of program quality and who experience difficulties in social interaction

The Role of Cool Girls, Inc. Participation and Parent-Child Relationship Quality in the Prediction of Social Capital and Hope for the Future among Female Youth

Social capital, or access to resources through relationships with other people, can facilitate the socioeconomic mobility of youth living in low-income communities. This study examined whether parent-child relationship quality and participation in a youth development program (YDP) were associated with gains in hope for the future, and whether those associations were mediated by parent social capital (i.e., access to resources through relationships with parents) and non-parent social capital (i.e., access to resources through relationships with people other than parents). The sample included 216 participants of one YDP program, Cool Girls, Inc., and 92 comparisons. Path analyses indicated that program participation for over one year predicted gains in non-parent social capital, and increases in both parent and non-parent social capital predicted increases in hope for the future. There was also evidence that first-year program participation was associated with gains in hope for the future. Implications for practice and research are discussed

Time-resolved Microwave Conductivity. Part 1.—TiO_2 Photoreactivity and Size Quantization

Charge-carrier recombination dynamics after laser excitation are investigated by time-resolved microwave conductivity (TRMC) measurements of quantum-sized (Q-) TiO_2, Fe^(III)-doped Q-TiO_2, ZnO and CdS, and several commercial bulk-sized TiO2 samples. After pulsed laser excitation of charge carriers, holes that escape recombination react with sorbed trans-decalin within ns while the measured conductivity signal is due to conduction-band electrons remaining in the semiconductor lattice. The charge-carrier recombination lifetime and the interfacial electron-transfer rate constant that are derived from the TRMC measurements correlate with the CW photo-oxidation quantum efficiency obtained for aqueous chloroform in the presence of TiO_2. The quantum efficiencies are 0. 4 % for Q-TiO_2, 1. 6 % for Degussa P25, and 2. 0 % for Fe^(III)-doped Q-TiO_2. The lower quantum efficiencies for Q-TiO_2 are consistent with the relative interfacial electron-transfer rates observed by TRMC for Q-TiO_2 and Degussa P25. The increased quantum efficiencies of Fe^(III)-doped Q-TiO_2 and the observed TRMC decays are consistent with a mechanism involving fast trapping of valence-band holes as Fe^(IV) and inhibition of charge-order recombination

Windows .NET Network Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST)

BACKGROUND: BLAST is one of the most common and useful tools for Genetic Research. This paper describes a software application we have termed Windows .NET Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST), which enhances the BLAST utility by improving usability, fault recovery, and scalability in a Windows desktop environment. Our goal was to develop an easy to use, fault tolerant, high-throughput BLAST solution that incorporates a comprehensive BLAST result viewer with curation and annotation functionality. RESULTS: W.ND-BLAST is a comprehensive Windows-based software toolkit that targets researchers, including those with minimal computer skills, and provides the ability increase the performance of BLAST by distributing BLAST queries to any number of Windows based machines across local area networks (LAN). W.ND-BLAST provides intuitive Graphic User Interfaces (GUI) for BLAST database creation, BLAST execution, BLAST output evaluation and BLAST result exportation. This software also provides several layers of fault tolerance and fault recovery to prevent loss of data if nodes or master machines fail. This paper lays out the functionality of W.ND-BLAST. W.ND-BLAST displays close to 100% performance efficiency when distributing tasks to 12 remote computers of the same performance class. A high throughput BLAST job which took 662.68 minutes (11 hours) on one average machine was completed in 44.97 minutes when distributed to 17 nodes, which included lower performance class machines. Finally, there is a comprehensive high-throughput BLAST Output Viewer (BOV) and Annotation Engine components, which provides comprehensive exportation of BLAST hits to text files, annotated fasta files, tables, or association files. CONCLUSION: W.ND-BLAST provides an interactive tool that allows scientists to easily utilizing their available computing resources for high throughput and comprehensive sequence analyses. The install package for W.ND-BLAST is freely downloadable from . With registration the software is free, installation, networking, and usage instructions are provided as well as a support forum

Modeling radiation belt radial diffusion in ULF wave fields: 2. Estimating rates of radial diffusion using combined MHD and particle codes

[1] Quantifying radial transport of radiation belt electrons in ULF wave fields is essential for understanding the variability of the trapped relativistic electrons. To estimate the radial diffusion coefficients (DLL), we follow MeV electrons in realistic magnetospheric configurations and wave fields calculated from a global MHD code. We create idealized pressure-driven MHD simulations for controlled solar wind velocities (hereafter referred to as pressure-driven Vx simulations) with ULF waves that are comparable to GOES data under similar conditions, by driving the MHD code with synthetic pressure profiles that mimic the pressure variations of a particular solar wind velocity. The ULF wave amplitude, in both magnetic and electric fields, increases at larger radial distance and during intervals with higher solar wind velocity and pressure fluctuations. To calculate DLL as a function of solar wind velocity (Vx = 400 and 600 km/s), we follow 90 degree pitch angle electrons in magnetic and electric fields of the pressure-driven Vx simulations. DLL is higher at larger radial distance and for the case with higher solar wind velocity and pressure variations. Our simulated DLL values are relatively small compared to previous studies which used larger wave fields in their estimations. For comparison, we scale our DLL values to match the wave amplitudes of the previous studies with those of the idealized MHD simulations. After the scaling, our DLL values for Vx = 600 km/s are comparable to theDLL values derived from Polar measurements during nonstorm intervals. This demonstrates the use of MHD models to quantify the effect of pressure-driven ULF waves on radiation belt electrons and thus to differentiate the radial diffusive process from other mechanisms

Assertiveness Training and Christian Values

Assertiveness training, like any psychotherapeutic procedure, requires an understanding and tolerate of various values of clients. Studies exploring the relationship between religious values and assertiveness are reviewed. Ideological obstacles in assertion training with religious clients are considered, and appropriate therapeutic strategies suggested. The importance of presenting a rationale for treatment and of understanding the client\u27s value system is emphasized