Determination of the Impact of Glycolate on Cs,Sr, and Actinide Separations in High-Level Waste

The Defense Waste Processing Facility (DWPF), responsible for vitrifying high-level waste (HLW) at the Savannah River Site (SRS), is planning to introduce glycolic acid as a reductant during chemical conditioning of the waste prior to vitrification. A portion of this glycolic acid may be recycled back to the tank farm as sodium glycolate. Since glycolate can serve as a complexing agent for a variety of metallic ions, recent studies were performed to examine the effect of glycolate on the removal of Sr and actinides by monosodium titanate (MST) and modified MST (mMST) and the separation of Cs by the caustic-side solvent extraction (CSSX) process.     

Training and dissemination of cognitive behavior therapy for depression in adults: A preliminary examination of therapist competence and client outcomes.

Objective: In this study, the authors examined the feasibility and effectiveness of training community therapists to deliver cognitive behavior therapy (CBT) for depression. Method: Participants were therapists (n = 12) and clients (n = 116; mean age = 41 years, 63% women) presenting for treatment of depression at a not-for-profit and designated community mental health center for St. Joseph County, Indiana. The training model included a 2-day workshop followed by 1 year of phone consultations. CBT competence ratings from the Cognitive Therapy Scale were obtained prior to training and at 6 and 12 months posttraining. Two different groups of clients, a treatment-as-usual (TAU) group (n = 74) and a CBT group (n = 42), were compared with respect to decrease in symptoms of depression (assessed with the Beck Depression Inventory) and anxiety (assessed with the Beck Anxiety Inventory). Results: Therapists showed significant increases in total scores from pretraining to 6 months posttraining, increases that were maintained at 12 months. The increase in the total score reflected gains on items that specifically measure CBT skills and structure. Although both TAU and CBT resulted in a significant decrease in depressive symptoms, the CBT clients showed significantly greater change than the TAU clients, F(2, 113) = 53.40, p     

薄膜光伏技术覆盖更宽的光谱范围

尽管薄膜硅太阳能电池的转换效率并不能和当今的主流技术相媲美,然而一旦考虑每千瓦（特）小时能量的生产成本,这项技术就能够脱颖而出。随着半导体和平板技术的发展,薄膜硅太阳能技术将能够帮助太阳能产业实现预期的宏伟目标,即太阳能发电成本与现有电力成本持平。     

Mesostructured island formation in sol-gel SiO2 films through controlled, concentration-dependent flocculation of colloidal silica particles

We have fabricated a number of films using various concentrations of colloidal silica particles in a sol-gel derived matrix. The particles were flocculated to tailor the surface properties of the film. Digital image analysis and profilometry were used to characterize the materials. We observe local maxima of floc size and film textural properties at 0.177 wt.% and within a very narrow range of particle concentration.     

Integration of Low-Impact Development into the International Stormwater BMP Database

Low impact development (LID) strategies are being encouraged in many communities as an approach to reduce potential adverse impacts of development on receiving streams. Many questions exist regarding how well various LID strategies perform in different settings, just as similar questions have been raised regarding performance of traditional stormwater best management practices (BMPs). Whereas historical focus on BMP performance has been water quality concentrations or loads, characterization of volume reduction benefits for both conventional and LID practices is increasingly an objective of researchers and stormwater managers. More than a decade ago, Urban Water Resources Research Council (UWRRC) members worked to develop a set of standardized monitoring and reporting protocols for traditional BMPs and to establish a master database for the purpose of evaluating BMP performance and the factors affecting performance. This effort culminated in the International Stormwater BMP Database (www.bmpdatabase.org), which contains data for more than 360 BMPs and continues to operate as a clearinghouse for stormwater BMP data and performance analyses. During 2008–2009, the International Stormwater BMP Database project expanded to better integrate LID into the database and develop a set of metrics that can be used to characterize BMP performance with regard to surface runoff volume reduction. This paper provides a condensed overview and progress report on the LID-focused effort, including the following topics: (1)?monitoring guidance for LID at the overall site development level, (2)?an overview of recent changes to the International Stormwater BMP Database to better accommodate LID studies, (3)?a summary of LID studies currently included in the database, and (4)?a proposed approach for evaluating performance of LID studies with regard to reducing surface runoff volumes.     

NSOM the fourth dimension: Integrating nanometric spatial and femtosecond time resolution

Photonic devices are becoming the cornerstone of next generation systems for computing and information processing. This paper reports on the first steps in the development of methods to understand these devices with nanometric (10^?7 cm) spatial and femtosecond (10^?15 s) time resolution. The basis of this achievement is the dramatic developments that have occurred in the past few years in a new area of optics called near-field optics. Near-field optics is a form of lensless optics with a resolution that is subwavelength and which is independent of the wavelength of the light being employed. We report in this paper the transmission of pulses with tens of femtosecond duration through subwavelength, near-field optical elements. We also report on a femtosecond near-field optical light source with cross-correlating capabilities and on the growth of GaAs in the tip of micropipettes for use as an ultra-fast electro-optical switch which can cross-correlate optical, electrical, and electro-optical effects. These developments are especially relevant in the investigation of photonic devices since such devices can alter their characteristics as a function of size in the mesoscopic regime from just below lens-based optical resolutions to dimensions that approach atomic scales of ～1 nm (10^?7 cm). In view of the fact that these devices and the processes that govern them also exhibit ultrafast speeds, the combination of state of the art femtosecond laser spectroscopy with the unique features of near-field optics is a critical step in advancing our next generation understandings of such materials and structures so that their full potential in information processing can be achieved.     

When sex, drugs, and violence enter the classroom: Conversations between adolescents and a female pedagogical agent

In this article, we investigate the discourse between a female conversational pedagogical agent and 59 adolescents in the context of a social studies lesson. We note that previous pedagogical agent research has focused on the positive effects of agents, while failing to take into account the intricacies of learner–agent discourse, and subsequently missing the abuse suffered by pedagogical agents at users’ fingertips. Our analysis indicates that learners readily misuse and abuse pedagogical agents while placing them in a subordinate and inferior role. We conclude by making recommendations on agent design and future research.     

Uncertainty Analysis of a Two-dimensional Hydrodynamic Model

First-Order Second Moment (FOSM) and Monte Carlo analysis were applied to characterize the uncertainty in selected water levels and velocities simulated by a two-dimensional hydrodynamic model of the Upper St. Lawrence River downstream from Lake Ontario. The analysis utilized an application of the Resource Management Associates’ RMA2 model. Both FOSM and Monte Carlo analysis provided similar estimates of uncertainty, with Monte Carlo analysis results being 15% less than FOSM. Based on the findings of this work, the FOSM is preferred. FOSM provides a conservative estimate of the uncertainty and it is simpler to apply than Monte Carlo analysis, requiring less information and fewer model executions. FOSM also provides an immediate indication of the primary contributors to the uncertainty in the output, where Monte Carlo analysis requires additional effort to do the same. Results indicate that the parameter describing bottom resistance using Manning's n contributed more to model uncertainty than other factors investigated. The uncertainty in and sensitivity in Manning's n is large which results in a significant amount of uncertainty in the model outputs is contributed by this parameter. The calculations described in this study show that uncertainty analysis is a practical addition to the two-dimensional hydrodynamic modelling process. It provides insight to the model developer, quantifying how good the model actually is. It also provides a measure of the accuracy of the model for future model developers or clients using hydrodynamic modeling outputs     

Novel biodegradable amino acid containing anhydride oligomers for orthopedic applications

Novel synthetic biodegradable methacrylated anhydride oligomers (MAOs) based on methacrylated alaninyl maleamic acid (MAMA) and methacrylated aminocaproyl maleamic acid (MACMA) were synthesized and characterized. Injectable and in situ crosslinkable polymer networks were formulated by the copolymerization of MAOs with triethylene glycol dimethacrylate (TEGDMA). Furthermore, composites composed of MAOs, TEGDMA, and β‐tricalcium phosphate were prepared. The networks and composites were initiated by photopolymerization and redox polymerization, respectively. The initial compressive strength (CS) and diametral tensile strength (DTS) of these materials were determined and used to evaluate the effects of the MAO/TEGDMA ratios on the degradation behavior of the materials. The MAMA‐based composites had initial DTS values of 5.7–17.1 MPa and CS values of 30.7–114.2 MPa. The MACMA‐based composites had initial DTS values of 2.8–20.8 MPa and CS values of 19.1–119.5 MPa. During the course of degradation, the neat polymer resins lost 97 and 87% of their initial CS values after 6 months with 50/50 MAMA/TEGDMA and MACMA/TEGDMA ratios, respectively. The composite with a 25/75 MACMA/TEGDMA ratio showed a significant increase in CS after an initial decrease for 7 days and then lost 57% of its initial CS value after 3 months. The composite composed of 100% methacrylated anhydride oligomer (MAOs) showed complete degradation after 21 days. The degrees of conversion of the neat resins were 60–77%. Both the neat resins and the composites had low polymerization shrinkage ranging from 3.8 to 5.6%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1979–1984, 2005     

Bone cell attachment and growth on well‐characterized chitosan films

Chitosan has been widely researched for bone tissue and implant applications. While initial results are promising, there are inconsistent reports regarding the biological responses. This may be due to inadequate evaluation of chitosan material properties. This study evaluated normal human osteoblast precursor cell attachment and proliferation on a series of well‐characterized chitosan films. The chitosan films exhibited a range of properties: 76–96% degree of de‐acetylation (DDA), 2400–8200 kDa viscosity‐average molecular weight, 62–90° contact angle, 0.24–2.46% residual ash, 5.3–287 µg cm^?2 residual protein and 23–40% crystallinity. There was no trend or correlation between DDA, crystallinity, contact angle, molecular weight, residual ash or protein content and the attachment or growth of bone cells on chitosan films. All films supported higher levels of bone cell proliferation than tissue culture plastic, which supports the general hypothesis that chitosans are osteocompatible. The 78 and 92% DDA chitosan films supported the most cell proliferation, approximately 16 times that of tissue culture plastic controls, but no chitosan physiochemical property correlated with the increased cell growth. The lack of correlation is hindered since more than one physiochemical property changed for each chitosan material. Data do indicate that there may be much variability in chitosan materials, and this variability may make understanding and comparing biological performance of chitosan materials difficult. These results highlight the need for systematic characterizations of chitosan materials for predictable biomedical applications. Copyright © 2006 Society of Chemical Industry