Evaluation of Modification of the Upper Batavia Dam on the Fox River, Illinois

Progress Report, Federal Aid Project F-136-R Segment 6Report issued on: August 2004Submitted to Office of Water Resources, Illinois Department of Natural Resource

Pinedale Deglaciation and Subsequent Holocene Environmental Changes and Geomorphic Responses in the Central Lemhi Mountains, Idaho, U.S.A.

In several glaciated valleys along the eastern front of the Lemhi Mountains, subalpine meadows are located along the central axes of the valleys, in positions immediately upvalley of arcuate Pinedale readvance moraines. The meadows are comprised of varying thicknesses of finegrained sediments which were impounded by the damning action of the moraines. These sediments, and pollen contained therein, record complex environmental fluctuations which accompanied déglaciation and postglacial recovery. The thickness of sediments in each meadow is a function of the proficiency of the arcuate moraines as dams. The presence of Glacier Peak B ash in one meadow illustrates that, at minimum, the lower one-third of that valley was deglaciated prior to approximately 11,250 yr BP. Over one meter of glacial-runoff sediments underlies the ash ; sedimentation rates in the meadow suggest that déglaciation in the lower portions of the valley may have been complete before 11,500 yr BP. Sedimentation rates slowed dramatically after 10,000 yr BP. A cold, early HoIocene climatic episode may have occurred around 7500 yr BP. Massive protalus landforms were deposited during the Indian Basin Advance. Later Neoglacial landforms were areally restricted to the most shaded, climatically-favorable locations.Dans plusieurs vallées glaciaires le long du front oriental des Lemhi Mountains, les prairies subalpines se situent le long des axes centraux, immédiatement en amont d'arcs morainiques mis en place lors d'une récurrence de l'épisode de Pinedale. Les prairies sont composées de sédiments d'épaisseur variable retenus dans des lacs derrière les moraines. Les sédiments et le pollen qu'ils contiennent ont enregistré les fluctuations complexes qu'a subi l'environnement et qui ont accompagné la déglaciation et le relèvement postglaciaire. L'épaisseur des sédiments est fonction de l'efficacité des barrages que constituaient les arcs morainiques. La présence de cendres volcaniques du type Glacier Peak B dans une des prairies démontre que le tiers inférieur de la vallée était libre de glace au moins avant 11 250 BP environ. Les cendres recouvrent plus d'un mètre de sédiments fluvioglaciaires. Les taux de sédimentation dans la prairie suggère que la déglaciation était terminée avant 11 500 BP dans les parties basses de la vallée. Les taux de sédimentation ont nettement diminué après 10 000 BP. Un épisode froid a probablement prévalu au début de l'Holocène, aux environs de 7500 BP. De gros bourrelets de congères ont été mis en place au cours de l'avancée d'lndian Basin. Plus tard, les formes néoglaciaires ne se trouvaient plus qu'aux endroits les plus ombragés et les plus propices du point de vue climatique.In mehreren glazialen Tàlern entlang der Ostfront der Lehmi Mountains befinden sich subalpine Wiesen entlang der zentralen Achsen der Tâler, direkt oberhalb der bogenfôrmigen RùckvorstoB-Morànen von Pinedale. Die Wiesen bestehen aus feinkômigen Sedimenten unterschiedlicher Dicke, welche durch die Damm-Wirkung der Morànen festgehalten wurden. Dièse Sedimente und derdarin enthaltene Pollen halten komplexe Umweltverânderungen fest, welche die Enteisung und die postglaziale Hebung begleitet haben. Die Dicke der Sedimente in jeder Weise ist abhàngig von der Damm-Wirkung der bogenfôrmigen Morânen. Das Vorkommen von Asche des Typs Glacier Peak B in einer der Wiesen zeigt, daB zumindest das untere Drittel dieses TaIs vor ungefàhr 11,250 Jahren v.u.Z. enteist war. Unter der Asche liegt mehr als ein Meter von glazialen AbfluB-Sedimenten; die Sedimentierungs-grade in der Wiese lassen vermuten, daB die Enteisung in den unteren Teilen des TaIs vor 11.500 Jahren v.u.Z. abgeschlossen war. Nach 10.000 Jahren v.u.Z. verlangsamten die Sedimentierungsgrade sich drastisch. Im frùhen Holozàn kônnte wohl eine kalte KIimatische Episode um 7.500 v.u.Z. eingetreten sein. Wàhrend des VorstoBes von Indian Basin wurden massive Protalus-Landformen abgelagert. Spàter waren neoglaziale Landformen ôrtlich begrenzt auf die schattigsten, klimatisch gùnstigsten Plâtze

Addressing Issues of Trust and Power Gap by Empowering Middle Leaders in an Asian International School

This Organizational Improvement Plan explores trust, leadership, and power at True North Academy (a pseudonym), a Canadian-themed international school in Asia. The Problem of Practice (PoP) recognizes a gap between the school’s current collaborative practices and its aspirations being a cutting-edge learning organization. Recent events, especially the global pandemic, have highlighted the school’s reliance on traditional hierarchies and top-down decision-making. Unpopular decisions made without staff input have damaged teacher trust in the leadership, raised concerns of a staff exodus, and stalled ongoing improvement of school programmes. Within a theoretical framework of social constructivism, a plan is proposed to address the challenges posed by declining trust and the power gap by exploring alternate approaches to decision-making within the senior school. Using a hybrid of Lewin’s stage change model and Duck’s five-stage change curve, the role of middle leaders will be broadened, empowering them as members of a more robust leadership team and in their interactions with their own followers. The solution described in this OIP is for middle leaders to build capacity by engaging in an ongoing Plan, Do, Study, Act (PDSA) cycle in which they learn to work together effectively and model distributive leadership practices within their own professional teams. Supporting middle leaders in redefining their own roles will draw upon the principles of adaptive and situational approaches that focus on their individual readiness, capacity, and emotional needs to ensure a positive transition into a more dynamic and inclusive vision of school leadership

Low-Voltage Bandgap Reference Design Utilizing Schottky Diodes

As semiconductor device geometries continue to shrink, the corresponding voltage applied across the processed devices must also be reduced. Therefore reference voltages used in integrated circuits will need to be reduced as well. A typical bandgap reference (BGR) voltage generator uses PN junction diodes or PNP BJT’s to bias the reference. The forward bias voltage of these devices is typically 0.7 volts, and has a limiting effect on how low a reference voltage can be generated, as well as how low a system voltage can be applied. Schottky, or metal-semiconductor (MS), diodes have a lower forward bias voltage, typically of about 0.3 volts. The implementation of Schottky metal-semiconductor diodes in place of PN diodes in the design of the BGR, should allow for lower reference voltage generation. This project consists of the design and simulation of a BGR utilizing MS diodes, followed by fabrication and validation of the design

Gamma-ray Bursts, Classified Physically

From Galactic binary sources, to extragalactic magnetized neutron stars, to long-duration GRBs without associated supernovae, the types of sources we now believe capable of producing bursts of gamma-rays continues to grow apace. With this emergent diversity comes the recognition that the traditional (and newly formulated) high-energy observables used for identifying sub-classes does not provide an adequate one-to-one mapping to progenitors. The popular classification of some > 100 sec duration GRBs as ``short bursts'' is not only an unpalatable retronym and syntactically oxymoronic but highlights the difficultly of using what was once a purely phenomenological classification to encode our understanding of the physics that gives rise to the events. Here we propose a physically based classification scheme designed to coexist with the phenomenological system already in place and argue for its utility and necessity.Comment: 6 pages, 3 figures. Slightly expanded version of solicited paper to be published in the Proceedings of ''Gamma Ray Bursts 2007,'' Santa Fe, New Mexico, November 5-9. Edited by E. E. Fenimore, M. Galassi, D. Palme

Paleomagnetism of the Chinle and Kayenta Formations, New Mexico and Arizona

Paleomagnetic data were obtained from 22 sites (6–10 samples/site) in the Upper Shale Member of the Chinle Formation, 43 sites in the Owl Rock Member of the Chinle Formation, and 35 sites in the Kayenta Formation. Thermal demagnetization and data analyses indicate that within-site dispersion is an important criterion for selecting sites which retain a high unblocking temperature characteristic remanent magnetization (ChRM). Site-mean directions define at least four antipodal polarity zones within each member/formation, suggesting the ChRM was acquired soon after deposition. Fifteen site-mean virtual geomagnetic poles (VGPs) from the Upper Shale Member of the Chinle Formation yield an early Norian paleomagnetic pole position of 57.4°N, 87.8°E (K = 60, A95 = 5.0°). Eighteen site-mean VGPs from the Owl Rock Member of the Chinle Formation yield a middle Norian paleomagnetic pole position of 56.5°N, 66.4°E (K = 183, A95 = 2.6°). Twenty-three site-mean VGPs from the Kayenta Formation yield a Pliensbachian pole position of 59.0°N, 66.6°E (K = 155, A95 = 2.4°). Combined with paleomagnetic poles from the Moenave Formation and the Shinarump Member of the Chinle Formation, these data record ∼30 m.y. of North American apparent polar wander (APW) within a regional stratigraphic succession. During the Camian and Norian stages of the Late Triassic, Chinle poles progress westward. During the Hettangian through Pliensbachian stages of the Early Jurassic, the pattern of APW changed to an eastward progression. Even after correction for 4° clockwise rotation of the Colorado Plateau, a sharp comer in the APW path (J1 cusp) is resolved near the pole from the Hettangian/Sinemurian (∼200 Ma) Moenave Formation (59.4°N, 59.2°E). Amongst other implications, the sharp change in the APW path at the J1 cusp implies an abrupt change from counterclockwise rotation of Pangea prior to 200 Ma to clockwise rotation thereafter

Paleomagnetism of the Middle Jurassic Summerville Formation, East Central Utah

The paleomagnetism of the late Callovian(?) Summerville Formation was analyzed to obtain a late Middle Jurassic paleomagnetic pole for North America. A total of 281 samples were collected from 35 sedimentary horizons (sites) in a single locality in the San Rafael Swell area of east central Utah. Fifteen site-mean characteristic remanent magnetization (ChRM) directions pass the reversals test and define at least five polarity zones within 52 m of stratigraphic section, suggesting that the ChRM was acquired upon, or soon after, deposition. Magnetizations of some specimens are complex, and several horizons yield anomalous site-mean directions. Data analysis included filtering to provide different combinations of virtual geomagnetic poles for calculation of the paleomagnetic pole. However, editing the data did not change the pole position by more than 5°. The preferred paleomagnetic pole position is 56.3°N, 133.4°E (A95 = 7.2°; N = 11 sites). The Summerville Formation paleomagnetic pole is located near the ∼172 Ma Corral Canyon pole and is statistically indistinguishable from the ∼151 Ma Glance Conglomerate and ∼149 Ma Lower Morrison poles. The paleomagnetic pole from the Summerville Formation is located at a much lower latitude and more easterly longitude than the paleomagnetic pole obtained from the ∼165 Ma Moat Volcanics of New England. We propose that the Jurassic North American apparent polar wander path is an age-progressive band at 55°N to 65°N latitude extending from ∼11°E longitude at ∼172 Ma to ∼150°E longitude at ∼149 Ma

Paleomagnetism of the Brushy Basin Member of the Morrison Formation: Implications for Jurassic apparent polar wander

The paleomagnetism of the ∼147 Ma (Tithonian) Brushy Basin Member of the Morrison Formation was analyzed to obtain a Late Jurassic paleomagnetic pole for North America. A total of 200 samples were collected from 25 sedimentary horizons (sites) at Norwood Hill in southwest Colorado. At Montezuma Creek in southeast Utah, 184 samples were collected from 26 sites. Detailed thermal demagnetization (up to nine temperature steps between 600°C and 680°C) and principal component analysis were required to confidently isolate characteristic remanent magnetization (ChRM) directions carried by hematite. Demagnetization behavior for many horizons is erratic and does not allow isolation of a high unblocking-temperature ChRM. Data selection criteria required sample ChRM directions to be defined by three or more thennal demagnetization steps and maximum angular deviations of sample ChRM directions to be ≤20°. Eight sites from the Norwood Hill location and 10 sites from the Montezuma Creek location passed these criteria. The 18 site-mean virtual geomagnetic poles yield a paleomagnetic pole position from the Brushy Basin Member of 68.3°N, 156.2°E (A95 = 4.8°, K = 53). This pole position is within 2° of the paleomagnetic pole which Steiner and Helsley (1975a) reported for the “upper” Morrison Formation at Norwood Hill, Colorado. A second paleomagnetic pole was calculated after excluding sites with site-mean α95 \u3e 20° and sites with fewer than three samples that passed the above selection criteria. This additional editing did not significantly change the paleomagnetic pole position at the 95% confidence level. Along with other paleomagnetic poles from the continental interior the paleomagnetic data from the Brushy Basin Member of the Morrison Formation are interpreted to indicate that the Late Jurassic part of the North American apparent polar wander path progresses from a late Middle Jurassic (∼160 Ma) position at ∼60°N, 135°E toward the mid-Cretaceous pole position at 72°N, 191°E