252 research outputs found
Turning the Tide: A Thoughtful and Developmentally Appropriate Approach to Teaching Mathematics
Describes the Bank Street School for Children program and approach to teaching mathematics, including the importance of undoing math phobia, a phenomenon in our society in which math is often viewed as unappealing, mysterious, and inaccessible.https://educate.bankstreet.edu/progressive/1017/thumbnail.jp
Substituent effects on the stability of metal chelates and further relationships in the Grunwald treatment of acid-base equilibria in hydroxylic solvents
A Randomized Controlled Trial of Parent-Child Interaction Therapy with and without Incentives in a Community Mental Health Setting
Disruptive behavior disorders (e.g., oppositional defiant disorder, conduct disorder) are the leading cause of referrals for children in mental health settings. Significant advancements in the implementation and dissemination of evidence-based family therapies have yielded successful reductions in these problem behaviors while also promoting long-term outcomes. Unfortunately, effective interventions such as Parent-Child Interaction Therapy (PCIT) are plagued with high rates of attrition and low rates of homework completion in community clinics. The current research study focused on evaluating the use of low cost incentives to increase retention and homework adherence in PCIT for a sample of low income, largely Hispanic families. Eighty-four families were randomly assigned to two groups: PCIT as usual or PCIT plus incentives. Findings indicated no significant differences between groups in rates of attendance, homework completion, or attainment of therapeutic skill mastery or graduation from treatment. Significant within-group outcomes were found for child behavior problems, internalizing and externalizing child behaviors, and parental stress, but no between-group differences were detected. A cost analysis between groups also was not significant. Exploratory analyses were conducted on factors contributing to early termination from treatment, therapy attitudes, and barriers to treatment participation. These analyses found that families who terminated from treatment early reported more difficulties with their children refusing to come to sessions, children developing new or different problems since starting treatment, and partners disagreeing with going to treatment. Additional analyses compared Hispanic and non-Hispanic families. Implications and future directions using innovative approaches to address attrition are discussed
Substituent effects of the stability of metal chelates
The stability constants of the chelate compounds of a series of substituted diaroylmethanes with several divalent metals in 75 per cent by volume dioxan-water were measured. The data were treated with the Hammett relationship
Further relationships in the grunwald treatment of acid-base equilibria in hydroxylic solvents
The problem under consideration is an attempt to establish a quantitative relationship among the basicities of a series of compounds. such a problem is trivial in the case in which all of the compounds of interest can be observed in the same medium. However, it frequently occurs that considerations of solubility and leveling effect of a solvent make it difficult or impossible to carry out suitable experiments. In these cases the experimenter\u27s only recourse generally has been to find a more suitable solvent
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Surrogate waste streams for use in MWFA funded research and development
Researchers developing technologies for treatment of mixed (both hazardous and radioactive) wastes are strongly encouraged to test using materials representative of the wastes targeted by their processes. Using actual wastes is essential for treatability studies and demonstrations prior to implementation, but is excessively costly and impractical during development. Thus, it is a responsibility of the focus area to provide researchers with surrogate recipes for use in development. Data from tests with standardized recipes will also facilitate comparison of results for competing technologies by potential end users and industry. Due to the wide range of waste materials in the DOE inventory and the scope of technology covered by the focus area, no one surrogate will accurately represent all wastes in all applications. The surrogates described are based on generic base compositions representative of that class of wastes, with variable constituents to be added over a recommended test range. Not all of the additives must be tested for each technology; focus should be directed to the constituents and physical forms present in the waste streams targeted by the developer. Excluding some parameters, or reducing the parametric testing rather than using the full range of concentration recommended simply limits the scope of potential application when the data is considered by a potential user. Surrogates are described for debris, sludges, and caustic scrub solution. Soils are recognized as a fourth class, and are considered too complex to represent with a surrogate. Descriptive text is also included to explain how the recipes were developed, and why each test additive is prescribed
Formulation, Casting, and Evaluation of Paraffin-Based Solid Fuels Containing Energetic and Novel Additives for Hybrid Rockets
This investigation studied the inclusion of various additives to paraffin wax for use in a hybrid rocket motor. Some of the paraffin-based fuels were doped with various percentages of LiAlH4 (up to 10%). Addition of LiAlH4 at 10% was found to increase regression rates between 7 - 10% over baseline paraffin through tests in a gaseous oxygen hybrid rocket motor. Mass burn rates for paraffin grains with 10% LiAlH4 were also higher than those of the baseline paraffin. RDX was also cast into a paraffin sample via a novel casting process which involved dissolving RDX into dimethylformamide (DMF) solvent and then drawing a vacuum on the mixture of paraffin and RDX/DMF in order to evaporate out the DMF. It was found that although all DMF was removed, the process was not conducive to generating small RDX particles. The slow boiling generated an inhomogeneous mixture of paraffin and RDX. It is likely that superheating the DMF to cause rapid boiling would likely reduce RDX particle sizes. In addition to paraffin/LiAlH4 grains, multi-walled carbon nanotubes (MWNT) were cast in paraffin for testing in a hybrid rocket motor, and assorted samples containing a range of MWNT percentages in paraffin were imaged using SEM. The fuel samples showed good distribution of MWNT in the paraffin matrix, but the MWNT were often agglomerated, indicating that a change to the sonication and mixing processes were required to achieve better uniformity and debundled MWNT. Fuel grains with MWNT fuel grains had slightly lower regression rate, likely due to the increased thermal conductivity to the fuel subsurface, reducing the burning surface temperature
Family-based treatments for serious juvenile offenders: A multilevel meta-analysis
__Objective:__ Researchers have identified several family-based treatments that hold considerable promise in reducing serious juvenile offending; however, these treatments remain underutilized by youth service systems. In the present study, we used meta-analysis to summarize the findings of research on family-based treatments for serious juvenile offenders.
__Method:__ We conducted a multilevel meta-analysis that modeled dependencies between multiple effect sizes from the same study. The meta-analysis synthesized 324 effect sizes from 28 studies that met inclusion criteria. Potential moderators (e.g., characteristics of samples, treatments, methods, and measures) were entered as fixed effects in the meta-analytic model.
__Results:__ Across studies, family-based treatments produced modest, yet long-lasting, treatment effects (mean d = 0.25 for antisocial behavior, 0.24 overall) relative to comparison conditions. Furthermore, certain characteristics moderated the magnitude of treatment effects; for example, measures of substance use showed the largest effects and measures of peer relationships showed the smallest effects.
__Conclusions:__ Policymakers, administrators, and treatment providers may find it useful to consider the effects of family-based treatments for serious juvenile offenders in their selection of treatments for this population. In addition, investigators who seek to develop and study such treatments may wish to consider the current findings in their future research efforts
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Radioactive waste incineration studies at the Los Alamos Scientific Laboratory
Development and demonstration of a transuranic (TRU) waste volume-reduction process is described. A controlled-air incinerator, based upon commercially available equipment and technology, was modified for radioactive service and was successfully tested and demonstrated with contaminated waste. Demonstration of the production-scale unit was completed in May 1980 with the incineration of 272 kg of waste with an average TRU content of about 20 nCi/g. Weight and volume reduction factors for the demonstration run were 40:1 and 120:1, respectively
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ASPEN computer simulations of the mixed waste treatment project baseline flowsheet
The treatment and disposal of mixed waste (i.e., waste containing both hazardous and radioactive components) is a challenging waste- management problem of particular concern to Department of Energy (DOE) sites throughout the United States. Traditional technologies used for destroying hazardous wastes must be re- evaluated for their ability to handle mixed wastes, and, in some cases, new technologies must be developed. The Mixed Waste Treatment Project (MWTP), a collaborative effort between Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory, and Pacific Northwest Laboratory (PNL), was established by the DOE`s Waste Operations Program (EM-30) to develop and analyze alternative mixed waste treatment approaches. One of the MWTP`s initiatives, and the objective of this study, was to develop flowsheets for prototype, integrated, mixed-waste treatment facilities that can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modeling. The objectives of the flowsheet simulations are to compare process effectiveness and costs of alternative flowsheets and to determine if commercial process-simulation software could be used on the large, complex process of an integrated mixed waste processing facility. Flowsheet modeling is needed to evaluate many aspects of proposed flowsheet designs. A major advantage of modeling the complete flowsheet is the ability to define the internal recycle streams, thereby making it possible to evaluate the impact of one operation on the whole plant. Many effects that can be seen only in this way. Modeling also can be used to evaluate sensitivity and range of operating conditions, radioactive criticality, and relative costs of different flowsheet designs. Further, the modeled flowsheets must be easily modified so that one can examine how alternative technologies and varying feed streams affect the overall integrated process
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