Influence of service-induced microstructural changes on the aging kinetics of rejuvenated Ni-based superalloy gas turbine blades

Rejuvenation of Ni-based superalloy gas turbine blades is widely and successfully employed in order to restore the material microstructure and properties after service at high temperature and stresses. Application of hot isostatic pressing (HIP) and re-heat treatment can restore even a severely overaged blade microstructure to practically “as-new” condition. However, certain service-induced microstructural changes might affect an alloy’s behavior after the rejuvenated blades are returned to service. It was found that advanced service-induced decomposition of primary MC carbides, and the consequent changes of the γ-matrix chemical composition during the rejuvenation, can cause a considerable acceleration of the aging process in the next service cycle. The paper will discuss the influence of the previous microstructural deterioration on the aging kinetics of rejuvenated gas turbine blades made from IN-738 and conventionally cast GTD-111 alloys.     

Studies on sulfur diffusion into Cu(In,Ga)Se2 thin films

A systematic study was carried out to investigate the distribution of sulfur (S) in CuInSe₂ (CIS) and Cu(In,Ga)Se₂ (CIGS) absorbers which were exposed to an H₂S atmosphere at elevated temperature. Results demonstrated that S diffusion into CIS layers was a strong function of the original stoichiometry of the absorber before sulfurization. Sulfur inclusion into Cu‐rich CIS films was much more favorable compared to S diffusion in Cu‐poor layers. The sulfur distribution profile was also strongly influenced by the micro‐structure of the original CIS and CIGS layers, with sections of the films with smaller grains accommodating more S. Copyright © 2000 John Wiley & Sons, Ltd.     

Using client feedback in psychotherapy training: An analysis of its influence on supervision and counselor self-efficacy.

Tracking client outcome and the therapeutic relationship across treatment (i.e., client feedback) has become a recommended practice for clinicians. This study investigated whether the utility of this practice would extend to trainees if the data gained from clients was provided to their supervisor for use within supervision. Trainees (N = 28) were assigned to a continuous feedback condition or no-feedback condition for 1 academic year. Results indicated that trainees in both conditions demonstrated better client outcomes at the end of their practicum training than at the beginning, but those in the feedback condition improved more. However, those in the feedback condition did not rate the supervisory alliance or satisfaction with the supervision process differently. The relationship between counselor self-efficacy and outcome was stronger for trainees in the feedback condition than for those in the no-feedback condition, perhaps indicating that feedback may facilitate a more accurate assessment of one’s skills. Implications of how counseling self-efficacy, the supervisory alliance, and satisfaction with supervision are related to effective supervision are addressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 14-bit 80-kHz sigma-delta A/D converter: modeling, design andperformance evaluation

The development is described of a sigma-delta A/D (analog-to-digital) converter. Included is a brief overview of sigma-delta conversion. The A/D converter achieves an 88.5-dB dynamic range and a maximum signal-to-noise ratio of 81.5 dB. The harmonic distortion is negligible. This level of performance is about 10 dB higher than previously reported results for oversampled A/D converters in this frequency range. The analog modulator uses a double-integration switched-capacitor architecture with an oversampling rate of 10.24 MHz. Transconductance amplifiers having a 160-MHz f_t were developed for the integrators. The circuit is implemented in a 1.75-μm 5-V CMOS process. The analog circuitry occupies 2 mm² of silicon area and consumes 75 mW of power. Some of the difficult problems associated with evaluating the performance of sigma-delta converters are described. The design of a sigma-delta development and performance evaluation system is presented. This system includes a custom interface board linking the chip to a Sun workstation, and extensive digital signal processing and analysis software     

Does a continuous feedback system improve psychotherapy outcome?

Using outcome data on a continual basis to monitor treatment progress has been identified as a way to enhance psychotherapy outcome. The purpose of this study was to investigate the use of a continuous feedback assessment system, the Partners for Change Outcome Management System (PCOMS; Miller & Duncan, 2004). Findings from 2 client samples that attended individual therapy at a university counseling center (N = 74) or a graduate training clinic (N = 74) indicated that clients who used PCOMS with their therapists (feedback condition) demonstrated statistically significant treatment gains when compared to clients receiving treatment as usual (no-feedback condition). Clients using PCOMS were also more likely to experience reliable change and in fewer sessions. A survival analysis demonstrated that approximately 50% of the clients in the feedback condition demonstrated reliable change after the 7th (graduate training clinic) or 9th session (university counseling center). Further findings, limitations of the study and ideas for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CIS film growth by metallic ink coating and selenization

A novel technique was demonstrated for the growth of CuInSe₂ (CIS) thin films. The technique used an ink formulation containing sub-micron size particles of Cu–In alloys. A metallic precursor layer was first formed by coating this ink onto the substrate by spraying. The precursor film was then made to react with Se to form the CIS compound. The morphology of the CIS layers depended on the initial composition of the Cu–In particles as well as the post-deposition treatments. Solar cells were fabricated on CIS absorber layers prepared by this low-cost ink-coating approach and devices with a conversion efficiency of over 10.5% were demonstrated.     

Reaction analysis of the formation of CuInSe2 films in a physical vapor deposition reactor

The reaction kinetics for the formation of CuInSe₂ films by reacting Cu/In layers with elemental selenium are compared with those for H₂Se. The species mole fractions as a function of time in a single Se-source physical vapor deposition (PVD) reactor are found to be essentially the same as those obtained in a chemical vapor deposition (CVD) reactor with flowing H₂Se, indicating that the same chemical equation representation can be used in both cases. The chemical engineering reaction analysis model developed previously by us is shown to predict adequately the experimental data in both reactors. The model is employed to predict three-source behavior. The effects of rate of species delivery and substrate temperature on the time to make CuInSe₂ is presented quantitatively. © 1998 John Wiley & Sons, Ltd.     

Effect of client feedback on couple psychotherapy outcomes.

Using outcome data to monitor the progress of treatment and the therapeutic alliance, also known as “client feedback” or “patient-focused research,” has yielded impressive results in individual psychotherapy. Client feedback has demonstrated reductions in premature terminations and improved psychotherapy outcomes. However, little research has been conducted using this paradigm with couples receiving therapy. The purpose of this study was to investigate whether the effectiveness of client feedback would extend to couple therapy. Results from a randomized couple clinical trial conducted in a naturalistic setting indicated that couples in a client feedback condition demonstrated statistically significantly more improvement compared with couples receiving treatment as usual and that improvement occurred more rapidly. Also, 4 times as many couples in the feedback condition reported clinically significant change by the end of treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An intelligent space robot for crew help and crew and equipment retrieval

This paper describes the development status of a prototype supervised intelligent robot for space application for purposes of (1) helping the crew of a spacecraft such as the Space Station with various tasks such as holding objects and retrieving/replacing tools and other objects from/into storage, and for purposes of (2) retrieving detached objects, such as equipment or crew, that have become separated from their spacecraft. In addition to this set of tasks in this low Earth orbiting spacecraft environment, it is argued that certain aspects of the technology can be viewed as generic in approach, thereby offering insight into intelligent robots for other tasks and environments.Some candidate requirements for the space applications are presented which will be refined by the results of the prototype development and evaluation testing. Our development approach is described, including space simulation environments used in developmental testing. Candidate software architectures and their key technical issues which enable real work in real environments to be accomplished safely and robustly are addressed.Results of computer simulations of retrieving detached objects, including the situated reasoning/reaction plan approach used, are presented, as well as the results of an air bearing floor simulation of retrieving detached objects.Also described are characterization results on the usable reduced gravity environment in an aircraft flying parabolas (to simulate weightlessness) and results on hardware performance there. These results show it is feasible to use that environment for evaluative testing of dexterous grasping based on real-time vision of freely rotating and translating objects.