Pyrotechnic shock at the orbiter/external tank forward attachment

During the initial certification test of the forward structural attachment of the space shuttle orbiter to the external tank, pyrotechnic shock from actuation of the separation device resulted in structural failure of the thermal protection tiles surrounding the attachment. Because of the high shock associated with the separation bolt, the development of alternative low shock separation designs was initiated. Two concepts that incorporate a 5.08 centimeter frangible nut as the release device were developed and tested

Broadband Access, District Policy, and Student Opportunities for Remote Learning During COVID-19 School Closures

We conceptualize students’ opportunities to learn remotely during the initial school closures associated with the COVID-19 pandemic. We then examine variation in remote instruction using an original statewide survey of teachers in Tennessee, deployed just a few weeks into the closures. Using three-level logistic regression models, we explore potential predictors of regular remote instruction, including prepandemic measures of broadband access, the demographic composition of schools, and measures of district policy responses created from districts’ public COVID-19 plans. We find that teachers in schools serving more economically disadvantaged students and in rural districts are less likely to report regular remote instruction, especially via providing digital resources and holding virtual classes or tutoring. Fewer opportunities for Tennessee’s rural students appear driven in part by lower community access to high-speed broadband, but district policies to distribute technology may partially mitigate this gap in access

Pacific Basin Heavy Oil Refining Capacity

The United States today is Canada’s largest customer for oil and refined oil products. However, this relationship may be strained due to physical, economic and political influences. Pipeline capacity is approaching its limits; Canadian oil is selling at substantive discounts to world market prices; and U.S. demand for crude oil and finished products (such as gasoline), has begun to flatten significantly relative to historical rates. Lower demand, combined with increased shale oil production, means U.S. demand for Canadian oil is expected to continue to decline. Under these circumstances, gaining access to new markets such as those in the Asia-Pacific region is becoming more and more important for the Canadian economy. However, expanding pipeline capacity to the Pacific via the proposed Northern Gateway pipeline and the planned Trans Mountain pipeline expansion is only feasible when there is sufficient demand and processing capacity to support Canadian crude blends. Canadian heavy oil requires more refining and produces less valuable end products than other lighter and sweeter blends. Canadian producers must compete with lighter, sweeter oils from the Middle East, and elsewhere, for a place in the Pacific Basin refineries built to handle heavy crude blends. Canadian oil sands producers are currently expanding production capacity. Once complete, the Northern Gateway pipeline and the Trans Mountain expansion are expected to deliver an additional 500,000 to 1.1 million barrels a day to tankers on the Pacific coast. Through this survey of the capacity of Pacific Basin refineries, including existing and proposed facilities, we have concluded that there is sufficient technical capacity in the Pacific Basin to refine the additional Canadian volume; however, there may be some modifications required to certain refineries to allow them to process Western Canadian crude. Any additional capacity for Canadian oil would require refinery modifications or additional refineries, both of which are not expected, given the volume of lighter and more valuable crude from the Middle East finding its way to Pacific Basin markets. Consequently, any new refinery capacity is not likely to be dedicated to Canadian crude shipments. This places increasing importance on the need to enter into long-term contracts to supply Pacific Basin refineries, backed up by evidence of adequate transportation capacity. Canadians will have to show first, and quickly, that we are committed to building pipelines that will bring sufficient volumes of oil to the Pacific coast necessary to give the refiners the certainty they need to invest in infrastructure for refining Canadian oil. Access to this crucial market will depend critically on the outcome of the pipeline approval process, and also the cost to ship from Canada. If Canada does not approve of the Pacific coast pipeline expansions, or takes too long in doing so, it could find its crude unable to effectively penetrate the world’s most promising oil export market

Catching the Brass Ring: Oil Market Diversification Potential for Canada

This paper examines the nature and structure of the Canadian oil export market in the context of world prices for heavy crude oil and the potential price differential available to Canadian producers gaining access to new overseas markets. Success in this arena will allow Canada to reap incredible economic benefits. For example, the near term benefits for increased access to Gulf Coast markets after mid-continent bottlenecks are removed, are significant, representing nearly 10$US per barrel for Canadian producers. On the Pacific Coast, the world market is represented by growing capacity for heavy crude products in emerging Asian markets including Japan, Korea and China and existing heavy crude facilities in California and the west coast. Here, in the reference scenario for California and Asia the benefits are assumed to begin in 2020. The differential value range in California in 2020 is estimated at$7.20US per barrel and escalates to $8.77US by 2030. In Asia, the benefit range is estimated to grow from$11.15US per barrel in 2020 to $13.60US in 2030. Those higher prices for Canadian heavy oil would translate into significant increases in profits, jobs and government revenues. With better access and new pipeline capacity, oil producers will see more efficient access to international markets which can add up to$131 billion to Canada’s GDP between 2016 and 2030 in the reference scenario. This amounts to over $27 billion in federal, provincial and municipal tax receipts, along with an estimated 649,000 person-years of employment. Alberta will be the principal but not sole beneficiary from increased access to world market pricing. Most provinces and territories will realize fiscal and economic gains from the distribution and sale of products reflecting reduced costs and increased access to refineries for heavy oil. The key to this change is the elimination of current bottlenecks in transport and the expansion of a network of pipelines that can move Canadian crude oil to locations reflecting minimal discounts from world market prices. As this paper demonstrates with hard facts and figures, the rewards are too great to ignore

University of North Florida Environmental Center Annual Report 2019

2019 Annual Report of the Environmental Center at the University of North Floridahttps://digitalcommons.unf.edu/ecenter_annual/1007/thumbnail.jp

Phylogenetics links monster larva to deep-sea shrimp.

Mid-water plankton collections commonly include bizarre and mysterious developmental stages that differ conspicuously from their adult counterparts in morphology and habitat. Unaware of the existence of planktonic larval stages, early zoologists often misidentified these unique morphologies as independent adult lineages. Many such mistakes have since been corrected by collecting larvae, raising them in the lab, and identifying the adult forms. However, challenges arise when the larva is remarkably rare in nature and relatively inaccessible due to its changing habitats over the course of ontogeny. The mid-water marine species Cerataspis monstrosa (Gray 1828) is an armored crustacean larva whose adult identity has remained a mystery for over 180 years. Our phylogenetic analyses, based in part on recent collections from the Gulf of Mexico, provide definitive evidence that the rare, yet broadly distributed larva, C. monstrosa, is an early developmental stage of the globally distributed deepwater aristeid shrimp, Plesiopenaeus armatus. Divergence estimates and phylogenetic relationships across five genes confirm the larva and adult are the same species. Our work demonstrates the diagnostic power of molecular systematics in instances where larval rearing seldom succeeds and morphology and habitat are not indicative of identity. Larval-adult linkages not only aid in our understanding of biodiversity, they provide insights into the life history, distribution, and ecology of an organism

Phylogeny of Stenopodidea (Crustacea: Decapoda) shrimps inferred from nuclear and mitochondrial genes reveals non-monophyly of the families Spongicolidae and Stenopididae, and most of their composite genera

The infraorder Stenopodidea is a relatively small group of marine decapod crustaceans including the well known cleaner shrimps, but their higher taxonomy has been rather controversial. This study provides the most comprehensive molecular phylogenetic analyses of Stenopodidea using sequence data from two mitochondrial (16S and 12S rRNA) and two nuclear (histone H3 and sodium–potassium ATPase α-subunit (NaK)) genes. We included all 12 nominal genera from the three stenopodidean families in order to test the proposed evolutionary hypothesis and taxonomic scheme of the group. The inferred phylogeny did not support the familial ranking of Macromaxillocarididae and rejected the reciprocal monophyly of Spongicolidae and Stenopididae. The genera Stenopus, Richardina, Spongiocaris, Odontozona, Spongicola and Spongicoloides are showed to be poly- or paraphyletic, with monophyly of only the latter three genera strongly rejected in the analysis. The present results only strongly support the monophyly of Microprosthema and suggest that Paraspongiola should be synonymised with Spongicola. The three remaining genera, Engystenopus, Juxtastenopus and Globospongicola, may need to be expanded to include species from other genera if their statuses are maintained. All findings suggest that the morphological characters currently adopted to define genera are mostly invalid and substantial taxonomic revisions are required. As the intergeneric relationships were largely unresolved in the present attempt, the hypothesis of evolution of deep-sea sponge-associated taxa from shallow-water free-living species could not be verified here. The present molecular phylogeny, nevertheless, provides some support that stenopoididean shrimps colonised the deep sea in multiple circumstances

Investigating the role of time in affective forecasting: temporal influences on forecasting accuracy.

Using extensive diary data from people taking their driver's license exam, the authors investigated the role of time in affective forecasting accuracy. Replicating existing findings, participants grossly overestimated the intensity and duration of their negative affect after failure and only slightly overestimated the intensity and duration of their positive affect after success. Extending existing findings, participants accurately predicted a decrease of their affective reactions over time but underestimated the speed with which this decrease would occur. In addition, they showed greater forecasting accuracy for positive affect than negative affect when the exam was distant and greater forecasting accuracy for negative affect than positive affect when the exam was close. The motivational processes underlying these findings are being discussed. © 2007 by the Society for Personality and Social Psychology, Inc