1,447 research outputs found
Regional price targets appropriate for advanced coal extraction
A methodology is presented for predicting coal prices in regional markets for the target time frames 1985 and 2000 that could subsequently be used to guide the development of an advanced coal extraction system. The model constructed is a supply and demand model that focuses on underground mining since the advanced technology is expected to be developed for these reserves by the target years. Coal reserve data and the cost of operating a mine are used to obtain the minimum acceptable selling price that would induce the producer to bring the mine into production. Based on this information, market supply curves can be generated. Demand by region is calculated based on an EEA methodology that emphasizes demand by electric utilities and demand by industry. The demand and supply curves are then used to obtain the price targets. The results show a growth in the size of the markets for compliance and low sulphur coal regions. A significant rise in the real price of coal is not expected even by the year 2000. The model predicts heavy reliance on mines with thick seams, larger block size and deep overburden
The great value of meat in the diet
Caption title.Digitized 2006 AES MoU.Includes bibliographical references
Task Persistence: A Potential Mediator of the Income-Achievement Gap
Background: The pervasive gap in achievement among impoverished children has been investigated primarily in terms of parental investments, specifically parent to child speech and other forms of cognitive stimulation (e.g., toys, print materials). This research extends that literature by considering the role of a non-cognitive factor, namely task persistence, in the income-achievement gap. Using task persistence as the hypothesized mediator, duration of childhood in poverty is used to predict two educational variables - perceived academic competence and educational attainment. Although bivariate relationships between each of the variables have been demonstrated in past research, a full model linking task persistence with the income-achievement gap has not been investigated thus far.
Methods: Using multiple waves of longitudinal data, duration of childhood poverty (ages 0-9) is used to predict both perceived academic competence (age 17) and educational attainment (age 23) with task persistence (average of ages 9, 13, 17) as a mediator.
Results: With task persistence included in each model, the relationships between duration of childhood in poverty and both perceived academic competence and educational attainment are significantly reduced, confirming a mediational influence of task persistence.
Conclusions: As hypothesized, task persistence statistically mediates the relationship between duration of childhood in poverty and educational outcomes. The implications of these findings on school success and intergenerational poverty are addressed, as well as suggestions for future research
Amplified erosion above waterfalls and oversteepened bedrock reaches
None of the conventional bedrock erosion laws can predict incision immediately upslope of a waterfall lip where the flow is accelerating toward a freefall. Considering the expected increase in flow velocity and shear stress at the lip of a waterfall, we determine erosion amplification at a waterfall lip as [equation], where [equation] is the erosion rate at the upstream end of the flow acceleration zone above a waterfall, Fr is the Froude number at this setting, and n ranges between 0.5–1.7. This amplification expression suggests that erosion at the lip could be as much as 2–5 times higher relative to erosion at a normal setting with identical hydraulic geometry. Utilizing this erosion amplification expression in numerical simulations, we demonstrate its impact on reach-scale morphology above waterfalls. Amplified erosion at the lip of a waterfall can trigger the formation of an oversteepened reach whose length is longer than the flow acceleration zone, provided incision wave velocity (Vi) at the upstream edge of the flow acceleration zone is higher than the retreat velocity of the waterfall face. Such an oversteepened reach is expected to be more pronounced when Vi increases with increasing slope. The simulations also suggest that oversteepening can eventually lead to steady state gradients adjacent to a waterfall lip provided Vi decreases with increasing slope. Flow acceleration above waterfalls can thus account, at least partially, for prevalent oversteepened bedrock reaches above waterfalls. Using the cosmogenic isotope Cl-36, we demonstrate that incision wave velocity upstream of a waterfall at the Dead Sea western escarpment is probably high enough for freefall-induced oversteepening to be feasible
Getting off obesity island: how informationists can enhance clinical decision support
Clinical decision support (CDS) will play a key role in improving the health of patients; informationists can support the development of CDS systems by indexing rule libraries and mapping the system logic. This work can help rule developers make more informed choices and understand how rules are related conceptually and operationally. With a map, rules can be written to bridge isolated concepts (islands) and rules that are no longer needed can be weeded. Here we explore the added value that informationists bring to projects by reporting on the role of informationists working on a pediatric CDS
The Development of a Driving Behavior Questionnaire for Veterans with Traumatic Brain Injury and Post-Traumatic Stress Disorder
Veterans returning home from combat deployment have been shown to be at an elevated risk of Motor Vehicle Accidents (MVAs), as evidenced by research after the Vietnam and Persian Gulf Wars. Both recent clinical observations and empirical findings have demonstrated that veterans of Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) may be at an increased level of risk from MVAs as compared to veterans of previous wars. The high percentage of post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) in this population may be contributing to this elevated risk; however, little research has been done on the topic of driving patterns in Iraq and Afghanistan combat veterans, and consequently data on the contributing factors of high-risk driving in this population are not readily available. To address this need, this study aimed to create a novel self-report measure for this population. First, by utilizing data from various sources of expert opinion on the topics of PTSD, TBI, veterans, and driving, the researchers narrowed down the possible contributors to high-risk driving. These findings were then condensed into a novel self-report assessment designed to elicit additional data on specific driving behaviors, high-anxiety driving situations, and the emotional and cognitive components of risky driving in this population. This study also compared the rates of high-risk driving in veterans diagnosed with TBI and PTSD against veterans without these diagnoses, and found that those with TBI/PTSD report more risky driving behaviors and significantly higher levels of anxiety while driving in certain situations. These data suggest that the emotional and psychological symptoms of TBI and PTSD may negatively impact driving safety in veterans.M.S., Psychology -- Drexel University, 201
Evaluation of tantalum for mercury containment in the SNAP-8 boiler
Corrosion testing of tantalum for mercury containment in SNAP 8 boile
Totally ordered commutative monoids
A totally ordered monoid - or tomonoid, for short - is a commutative semigroup with identity S equipped with a total order ≤s that is translation invariant, i.e., that satisfies: ∀x, y, z ∈, x ≤s y ⇒ x + z ≤s y + z. We call a tomonoid that is a quotient of some totally ordered free commutative monoid formally integral. Our most significant results concern characterizations of this condition by means of constructions in the lattice Zn that are reminiscent of the geometric interpretation of the Buchberger algorithm that occurs in integer programming. In particular, we show that every two-generator tomonoid is formally integral. In addition, we give several (new) examples of tomonoids that are not formally integral, we present results on the structure of nil tomonoids and we show how a valuation-theoretic construction due to Hion reveals relationships between formally integral tomonoids and ordered commutative rings satisfying a condition introduced by Henriksen and Isbell
Mapping the rules: conceptual and logical relationships in a system for pediatric clinical decision support
The Child Health Improvement through Computer Automation (CHICA) system uses evidence-based guidelines and information collected in the clinic and stored in an electronic medical record (EMR) to inform physician and patient decision making. CHICA helps physicians to identify and select relevant screenings and also provides personalized, just-in-time information for patients. This system relies on a database of Medical Logic Modules (MLMS) written in the Arden Rules syntax. These MLMs store observations (StorObs) during the clinical encounter which trigger potential screenings and preventive health interventions for discussion with the patient or for follow up at the next visit. This poster shows how informationists worked with the CHICA team to describe the MLMs using standard vocabularies, including Medical Subject Headings (MeSH) and Logical Observation Identifiers Names and Codes (LOINC). After assigning keywords to the database of MLMs, the informationists used visualization tools to generate maps. These maps show how rules are related by logic (shared StorObs) and by concept (shared vocabulary). The CHICA team will use these maps to identify gaps in the clinical decision support database and (if needed) to develop rules which bridge related but currently isolated concepts.NIH 1R01LM010923-0
Constraints on the tectonic and landscape evolution of the Bhutan Himalaya from thermochronometry
The observed geomorphology and calculated thermal histories of the Bhutan Himalaya provide
an excellent platform to test ideas regarding the influence of tectonics and climate on the evolution of a
convergentmountain range. However, little consensus has been reached regarding the late Cenozoic history of
the Bhutan Himalaya. Some researchers have argued that observed geologic relationships show slowing
deformation rates, such that the range is decaying from a geomorphic perspective, while others see the range
as growing and steepening. We suggest that a better understanding is possible through the integrated
interpretation of geomorphic and thermochronometric data from the comparison of predictions from models
of landscape evolution and thermal-kinematic models of orogenic systems. New thermochronometric data
throughout Bhutan aremost consistent with a significant decrease in erosion rates, from2 to 3 km/Ma down to
0.1–0.3 km/Ma, around 6–4Ma. We interpret this pattern as a decrease in rock uplift rates due to the activation
of contractional structures of the Shillong Plateau, an uplifted region approximately 100 km south of Bhutan.
However, low-relief, fluvial landscapes throughout the Bhutanese hinterland record a late pulse of surface uplift
likely due to a recent increase in rock uplift rates. Constraints from our youngest thermochronometers suggest
that this increase in rock uplift and surface uplift occurred within the last 1.75Ma. These results imply that
the dynamics of the Bhutan Himalaya and Shillong Plateau have been linked during the late Cenozoic, with
structural elements of both regions active in variable ways and times over that interval
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