371 research outputs found
Evidence for Premetamorphic Faulting in the Rangeley Quadrangle, Western Maine
Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: Trip
Stratigraphy of the Northwest Limb of the Merrimack Synclinorium in the Kennebago Lake, Rangeley, and Phillips Quadrangles, Western Maine
Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: Trip A-
Deuda pública "cierta" y "contingente": el caso de Colombia
Este documento examina la dinámica de la deuda pública colombiano, distinguiendo entre la deuda cierta y la deuda contingente. Los ejercicios tradicionales sobre sostenibilidad de la deuda rara vez incluyen los efectos de la deuda contingente. Nuestros resulttulos indican que se requiere generar un ahorro primario equivalente al 3% del PIB para estabilizar la relación deuda pública/PIB alrededor del 50%
Bedrock geology of the Rangeley Lakes-Dead River basin region, western Maine
Guidebook for field trips in the Rangeley Lakes - Dead River Basin region, western Maine: 62nd annual meeting October 2, 3, and 4, 1970: title page, table of contents, foreword, essa
Silylation of titanium-containing amorphous silica catalyst: effect on the alkenes epoxidation with H2O2
The surface of a Ti/SiO2 catalyst was silylated using hexamethyldisilazane (HMDS) and tetramethyldisilazane (TMDS) as silylating reagents in vapor phase. The silylation of silanol (Si–OH) on the catalysts was confirmed by diffuse reflectance UV-Vis, DRIFT spectroscopy and solid-state 29Si MAS NMR techniques. Silylation with TMDS improves the catalytic performance of Ti/SiO2 catalyst more significantly than with HMDS and this is mainly due to the steric bulk effects of trimethylsilyl groups from HMDS as compared to dimethylsilyl groups from TMDS. The silylation degree with TMDS was found to be higher than with HMDS and no changes in the silylation degree with TMDS was observed for silylation times longer than 2 h. Despite the silylation route employed, the silylated surface is hydrophobic which enhances not only in hydrogen peroxide efficiency but also and in selectivity to epoxide in the epoxidation of alkenes with H2O2. These effects are more evident when the hydrogen peroxide concentration is higher and particularly for the catalyst modified with TMDS.Peer reviewe
An interdisciplinary framework for measuring and supporting adherence in HIV prevention trials of ARV‐based vaginal rings
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138229/1/jia29158.pd
Relationship of homestead food production with night blindness among children below 5 years of age in Bangladesh
Abstract Objective To examine the relationship between homestead food production and night blindness among pre-school children in rural Bangladesh in the presence of a national vitamin A supplementation programme. Design A cross-sectional study. Setting A population-based sample of six rural divisions of Bangladesh assessed in the Bangladesh Nutrition Surveillance Project 2001-2005. Subjects A total of 158 898 children aged 12-59 months. Results The prevalence rates of night blindness in children among those who did and did not receive vitamin A capsules in the last 6 months were 0·07 % and 0·13 %, respectively. Given the known effect of vitamin A supplementation on night blindness, the analysis was stratified by children's receipt of vitamin A capsules in the last 6 months. Among children who did not receive vitamin A capsules in the last 6 months, the lack of a home garden was associated with increased odds of night blindness (OR = 3·16, 95 % CI 1·76, 5·68; P = 0·0001). Among children who received vitamin A capsules in the last 6 months, the lack of a home garden was not associated with night blindness (OR = 1·28, 95 % CI 0·71, 2·31; P = 0·4). Conclusions Homestead food production confers a protective effect against night blindness among pre-school children who missed vitamin A supplementation in rural Banglades
Unconfined Aquifer Flow Theory - from Dupuit to present
Analytic and semi-analytic solution are often used by researchers and
practicioners to estimate aquifer parameters from unconfined aquifer pumping
tests. The non-linearities associated with unconfined (i.e., water table)
aquifer tests makes their analysis more complex than confined tests. Although
analytical solutions for unconfined flow began in the mid-1800s with Dupuit,
Thiem was possibly the first to use them to estimate aquifer parameters from
pumping tests in the early 1900s. In the 1950s, Boulton developed the first
transient well test solution specialized to unconfined flow. By the 1970s
Neuman had developed solutions considering both primary transient storage
mechanisms (confined storage and delayed yield) without non-physical fitting
parameters. In the last decade, research into developing unconfined aquifer
test solutions has mostly focused on explicitly coupling the aquifer with the
linearized vadose zone. Despite the many advanced solution methods available,
there still exists a need for realism to accurately simulate real-world aquifer
tests
Dynamic factor model with infinite-dimensional factor space:forecasting
The paper compares the pseudo real-time forecasting performance of three Dynamic Factor Models: (i) The standard principal-component model introduced by Stock and Watson in 2002, (ii) The model based on generalized principal components, introduced by Forni, Hallin, Lippi and Reichlin in 2005, (iii) The model recently proposed by Forni, Hallin, Lippi and Zaffaroni in 2015. We employ a large monthly dataset of macroeconomic and financial time series for the U.S. economy, which includes the Great Moderation, the Great Recession and the subsequent recovery (an update of the so-called Stock and Watson dataset). Using a rolling window for estimation and prediction, we find that (iii) significantly outperforms (i) and (ii) in the Great Moderation period for both Industrial Production and Inflation, that (iii) is also the best method for Inflation over the full sample. However, (iii) is outperformed by (ii) and (i) over the full sample for Industrial Production
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