840 research outputs found

    Active control system trends

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    The active control concepts which achieve the benefit of improved mission performance and lower cost and generate system trends towards improved dynamic performance, more integration, and digital fly by wire mechanization are described. Analytical issues and implementation requirements and tools and approaches developed to address the analytical and implementation issues are briefly discussed

    Visualization of defect-induced excitonic properties of the edges and grain boundaries in synthesized monolayer molybdenum disulfide

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    Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDCs) are attractive materials for next generation nanoscale optoelectronic applications. Understanding nanoscale optical behavior of the edges and grain boundaries of synthetically grown TMDCs is vital for optimizing their optoelectronic properties. Elucidating the nanoscale optical properties of 2D materials through far-field optical microscopy requires a diffraction-limited optical beam diameter sub-micron in size. Here we present our experimental work on spatial photoluminescence (PL) scanning of large size ( 50\geq 50 microns) monolayer MoS2_2 grown by chemical vapor deposition (CVD) using a diffraction limited blue laser beam spot (wavelength 405 nm) with a beam diameter as small as 200 nm allowing us to probe nanoscale excitonic phenomena which was not observed before. We have found several important features: (i) there exists a sub-micron width strip (500\sim 500 nm) along the edges that fluoresces 1000%\sim 1000 \% brighter than the region far inside; (ii) there is another brighter wide region consisting of parallel fluorescing lines ending at the corners of the zig-zag peripheral edges; (iii) there is a giant blue shifted A-excitonic peak, as large as 120\sim 120 meV, in the PL spectra from the edges. Using density functional theory calculations, we attribute this giant blue shift to the adsorption of oxygen dimers at the edges, which reduces the excitonic binding energy. Our results not only shed light on defect-induced excitonic properties, but also offer an attractive route to tailor optical properties at the TMDC edges through defect engineering.Comment: 10 pages, 4 figures in Journal of Physical Chemistry C, 201

    Coffee and cocoa value chains: Gender dynamics in Peru and Nicaragua

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    The present report assesses women’s and men’s participation in coffee and cocoa value chains in Latin America in order to identify key considerations and next steps for the development of research, policy and practice on value chain upgrading for enhanced smallholder prosperity. In particular, the report analyzes the differential roles that women and men play and the benefits they perceive from their participation in coffee and cocoa value chains. It also considers the role of producer organizations in limiting or enhancing women’s participation and benefits from coffee and cocoa value chains. The report first reviews existing studies of gender and coffee and cocoa value chains in Latin American countries in order to identify principal trends; then, the paper focuses on Peru and Nicaragua as two country cases. In general, the report demonstrates that while factors such as labor burdens, access to productive resources, and socio-cultural norms can limit women’s participation in and returns from coffee and cocoa value chains in comparison to that of men, varied initiatives have sought to address these restricting conditions via producer organizations. The extent and circumstances of their success in advancing gender equality in coffee and cocoa value chains will be an important area for future analysis

    A gender synchronized family planning intervention for married couples in rural India: study protocol for the CHARM2 cluster randomized controlled trial evaluation.

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    BackgroundPrior research from India demonstrates a need for family planning counseling that engages both women and men, offers complete family planning method mix, and focuses on gender equity and reduces marital sexual violence (MSV) to promote modern contraceptive use. Effectiveness of the three-session (two male-only sessions and one couple session) Counseling Husbands to Achieve Reproductive Health and Marital Equity (CHARM) intervention, which used male health providers to engage and counsel husbands on gender equity and family planning (GE + FP), was demonstrated by increased pill and condom use and a reduction in MSV. However, the intervention had limited reach to women and was therefore unable to expand access to highly effective long acting reversible contraceptives such as the intrauterine device (IUD). We developed a second iteration of the intervention, CHARM2, which retains the three sessions from the original CHARM but adds female provider- delivered counseling to women and offers a broader array of contraceptives including IUDs. This protocol describes the evaluation of CHARM2 in rural Maharashtra.MethodsA two-arm cluster randomized controlled trial will evaluate CHARM2, a gender synchronized GE + FP intervention. Eligible married couples (n = 1200) will be enrolled across 20 clusters in rural Maharashtra, India. Health providers will be gender-matched to deliver two GE + FP sessions to the married couples in parallel, and then a final session will be delivered to the couple together. We will conduct surveys on demographics as well as GE and FP indicators at baseline, 9-month, and 18-month follow-ups with both men and women, and pregnancy tests at each time point from women. In-depth interviews will be conducted with a subsample of couples (n = 50) and providers (n = 20). We will conduct several implementation and monitoring activities for purposes of assuring fidelity to intervention design and quality of implementation, including recruitment and tracking logs, provider evaluation forms, session observation forms, and participant satisfaction surveys.DiscussionWe will complete the recruitment of participants and collection of baseline data by July 2019. Findings from this work will offer important insight for the expansion of the national family planning program and improving quality of care for India and family planning interventions globally.Trial registrationClinicalTrial.gov, NCT03514914

    CHARM, a gender equity and family planning intervention for men and couples in rural India: protocol for the cluster randomized controlled trial evaluation.

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    BackgroundGlobally, 41% of all pregnancies are unintended, increasing risk for unsafe abortion, miscarriage and maternal and child morbidities and mortality. One in four pregnancies in India (3.3 million pregnancies, annually) are unintended; 2/3 of these occur in the context of no modern contraceptive use. In addition, no contraceptive use until desired number and sex composition of children is achieved remains a norm in India. Research shows that globally and in India, the youngest and most newly married wives are least likely to use contraception and most likely to report husband's exclusive family planning decision-making control, suggesting that male engagement and family planning support is important for this group. Thus, the Counseling Husbands to Achieve Reproductive Health and Marital Equity (CHARM) intervention was developed in recognition of the need for more male engagement family planning models that include gender equity counseling and focus on spacing contraception use in rural India.Methods/designFor this study, a multi-session intervention delivered to men but inclusive of their wives was developed and evaluated as a two-armed cluster randomized controlled design study conducted across 50 mapped clusters in rural Maharashtra, India. Eligible rural young husbands and their wives (N = 1081) participated in a three session gender-equity focused family planning program delivered to the men (Sessions 1 and 2) and their wives (Session 3) by village health providers in rural India. Survey assessments were conducted at baseline and 9&18 month follow-ups with eligible men and their wives, and pregnancy tests were obtained from wives at baseline and 18-month follow-up. Additional in-depth understanding of how intervention impact occurred was assessed via in-depth interviews at 18 month follow-up with VHPs and a subsample of couples (n = 50, 2 couples per intervention cluster). Process evaluation was conducted to collect feedback from husbands, wives, and VHPs on program quality and to ascertain whether program elements were implemented according to curriculum protocols. Fidelity to intervention protocol was assessed via review of clinical records.DiscussionAll study procedures were completed in February 2015. Findings from this work offer important contributions to the growing field of male engagement in family planning, globally.Trial registrationClinicalTrial.gov, NCT01593943

    The impact of an integrated approach to science and literacy in elementary school classrooms

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    This study investigates the efficacy of an integrated science and literacy approach at the upper‐elementary level. Teachers in 94 fourth grade classrooms in one Southern state participated. Half of the teachers taught the treatment unit, an integrated science–literacy unit on light and energy designed using a curriculum model that engages students in reading text, writing notes and reports, conducting firsthand investigations, and frequent discussion of key concepts and processes to acquire inquiry skills and knowledge about science concepts, while the other half of the teachers taught a content‐comparable science‐only unit on light and energy (using materials provided by their districts) and provided their regular literacy instruction. Students in the treatment group made significantly greater gains on measures of science understanding, science vocabulary, and science writing. Students in both groups made comparable gains in science reading comprehension. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 631–658, 2012Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91115/1/tea_21015_sm_SuppAppendix.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91115/2/21015_ftp.pd

    The Gendered Politics of Natural Resource Management: Gender Mainstreaming in UN-REDD+ Programs in Latin America

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    This paper uses a feminist political ecology framework to critically examine rural women’s relationship with UN-REDD programs throughout Latin America. It looks at the ways in which UN-REDD has attempted to integrate women into the larger REDD+ development paradigms vis-à-vis gender- mainstreaming. I pay particular attention to how gender dynamics operate in the context of REDD+ with respect to cultural sovereignty, access to land, and benefit sharing and draw on Ecuador’s National REDD+ Socio Bosque program to illuminate how National REDD+ programs can adversely affect rural women’s livelihoods despite UN-REDD’s discourse of “gender equality”. In light of these considerations, I argue that UN-REDD programs disadvantage women disproportionately and posit UN-REDD’s gender mainstreaming initiatives as ill equipped to address the concerns of activists and community members speaking out against REDD+ in their territories

    Development of control systems for space shuttle vehicles, volume 1

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    Control of winged two-stage space shuttle vehicles was investigated. Control requirements were determined and systems capable of meeting these requirements were synthesized. Control requirements unique to shuttles were identified. It is shown that these requirements can be satisfied by conventional control logics. Linear gain schedule controllers predominate. Actuator saturations require nonlinear compensation in some of the control systems
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