Cost-Effectiveness Analysis of Early Reading Programs: A Demonstration With Recommendations for Future Research

We review the value of cost-effectiveness analysis for evaluation and decision making with respect to educational programs and discuss its application to early reading interventions. We describe the conditions for a rigorous cost-effectiveness analysis and illustrate the challenges of applying the method in practice, providing examples of programs for which we have estimated costs, but find effectiveness data lacking in comparability. We provide a demonstration of how cost-effectiveness analysis can be applied to two early reading programs: the Wilson Reading System and Corrective Reading. We use existing effectiveness data from an experimental evaluation in which the programs were implemented under similar conditions and the use of common outcomes measures for both programs yielded data that are comparable. We combine these data with cost data we collected using the ingredients method to calculate cost-effectiveness ratios for the alphabetics domain. A complete picture of the relative cost-effectiveness of each program could be provided if effectiveness metrics were available for fluency, vocabulary, and comprehension. We highlight the obstacles to applying cost-effectiveness analysis more frequently and recommend strategies for improving the availability of the requisite data

Cost-effectiveness Analysis of Interventions that Improve High School Completion

This report demonstrates the methods of cost-effectiveness analysis as applied to several educational programs that have been shown to improve the rate of high school completion

Improving Early Literacy: Cost-Effectiveness Analysis of Effective Reading Programs

This study is a cost-effectiveness analysis of seven early literacy programs that have all been previously identified as effective at improving reading outcomes for students in Grades K-3. We use the ingredients method to collect cost data for each program and compare the cost-effectiveness of programs serving students in the same grade level

Characterization of manufacturing-induced surface scratches and their effect on laser damage resistance performance of diamond fly-cut KDP crystal

Manufacturing-induced defects have drawn more and more attentions to improve the laser damage resistance performance of KDP crystal applied in high-power laser systems. Here, the morphology of surface scratches on diamond fly-cut KDP crystal is characterized and their effect on the laser damage resistance is theoretically and experimentally investigated. The results indicate that surface scratches could lower laser-induced damage threshold (LIDT) by modulating incident lasers and producing resultant local light intensifications. The induced maximum light intensity enhancement factors (LIEFs) are dependent on scratch shapes and dimensions. The diffraction effects originating from scratch edges are responsible for the strongest light intensification. Even for ultra-precision finished KDP surface with scratches that well satisfy the currently applied scratch/dig specification, the induced LIEFs are quite high, indicating that the actual defect dimension allowance should be amended and specified according to the defect-induced LIEFs. The effect of scratches on laser damage resistance is experimentally verified by the tested LIDT, which is approximately consistent with the simulation one. The morphologies of laser damage sites further confirm the role of scratches in lowering LIDT. This work could offer new perspective and guidance for fully evaluating the performance of ultra-precision manufactured optical materials applied in high-power laser facilities

Cassava genome from a wild ancestor to cultivated varieties

Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology

Recent advances in graphene based materials as anode materials in sodium-ion batteries

Sodium-ion batteries (SIBs) have emerged as a promising alternative to Lithium-ion batteries (LIBs) for energy storage applications, due to abundant sodium resources, low cost, and similar electrochemical performance. However, the large radius of Na+ and high molar mass compared to Li+, result in large volume strain during charge/discharge and low reversible capacity and poor cycling stability. Due to exceptional physical and chemical properties, graphene has attracted increasing attention as a potential anode material for SIBs. When integrated with other nanomaterials in electrodes, graphene can improve the electrical conductivity, accommodate the large volume change and enhance reaction kinetics. This paper provides a systematic review of recent progress in the application of graphene based anodes for SIBs, with a focus on preparation, structural configuration, Na+ storage mechanism and electrochemical performance. Additionally, some challenges and future perspectives are provided to improve the sodium storage performance of graphene based electrodes

Coating Fe2O3 with graphene oxide for high-performance sodium-ion battery anode

Sodium-ion batteries (SIBs) have recently shown the potential to meet the demands for large scale energy storage needs as an attractive alternative to lithium-ion batteries due to the high abundance of sodium resources around the world. The major hurdle of SIBs resides in developing viable anode materials with a high energy density and an appropriately long cycle life. Here a simple and low-cost method for synthesizing Fe2O3/graphene oxide (Fe2O3/GO) composites made out of Fe2O3 nanoparticles sandwiched between graphene oxide (GO) layers is reported. The unique structure of the Fe2O3/GO composites served a synergistic effect to alleviate the stress of Fe2O3 nanoparticles, prevent nanoparticles aggregation, maintain the mechanical integrity of the electrode, and facilitate mass transfer of Na ions during batteries operating. Consequently, the Fe2O3/GO composites as anode for SIBs attained a reversible specific capacity of ca. 420 mAh g-1 after 100 cycles at 0.1C (1C=1007 mA g-1) and a good rate capability at various current densities. Moreover, the Coulombic efficiency of the SIBs could rapidly increase in the early cycles. Due to the facile synthesis method and high electrochemical performance, the Fe2O3/GO composites would have a significant potential as anode materials for rechargeable SIBs

Cu nanoparticles supported on graphitic carbon nitride as an\ud efficient electrocatalyst for oxygen reduction reaction

High active and cost-effective electrocatalysts for the oxygen reduction reaction (ORR) are essential components of renewable energy technologies, such as fuel cells and metal/air batteries. Herein, we propose that ORR active Cu/graphitic carbon nitride (Cu/g-CN) electrocatalyst can be prepared via a facile hydrothermal reaction in the present of the ionic liquid (IL) bis(1-hexadecyl-3-methylimid- azolium) tetrachlorocuprate[(C₁₆mim)₂CuCl₄] and protonated g-CN. The as-prepared Cu/g-CN showed an impressive ORR catalytic activity that a 99 mV positive shift of the onset potential and 2 times kinetic current density can be clearly observed, comparing with the pure g-CN. In addition, the Cu/g-CN revealed better stability and methanol tolerance than commercial Pt/C (HiSPECTM 3000, 20%). Therefore, the proposed Cu/g-CN, as the inexpensive and efficient ORR electrocatalyst, would be a potential candidate for application in fuel cells