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1

The Formation of Uranus and Neptune in Solid-Rich Feeding Zones: Connecting Chemistry and Dynamics  

NASA Astrophysics Data System (ADS)

The core accretion theory of planet formation has at least two fundamental problems explaining the origins of Uranus and Neptune: (1) dynamical times in the trans-saturnian solar nebula are so long that core growth can take >15 Myr and (2) the onset of runaway gas accretion that begins when cores reach 10 Earth masses necessitates a sudden gas accretion cutoff just as Uranus and Neptune's cores reach critical mass. Both problems may be resolved by allowing the ice giants to migrate outward after their formation in solid-rich feeding zones with planetesimal surface densities well above the minimum-mass solar nebula. We present new simulations of the formation of Uranus and Neptune in the solid-rich disk of Dodson-Robinson et al. (2009) using the initial semimajor axis distribution of the Nice model, with one ice giant forming at 12 AU and the other at 15 AU. The innermost ice giant reaches its present mass after 3.8-4.0 Myr and the outermost after 5.3-6 Myr, a considerable time decrease from previous one-dimensional simulations (e.g. Pollack et al. 1996). The core masses stay subcritical, eliminating the need for a sudden gas accretion cutoff. Our calculated carbon mass fractions of 22% are in excellent agreement with the ice giant interior models of Podolak et al. (1995). Based on the requirement that the ice giant-forming planetesimals contain >10% mass fractions of methane ice, we can reject any Solar System formation model that initially places Uranus and Neptune inside of Saturn's orbit. We also demonstrate that a large population of planetesimals must be present in both ice giant feeding zones throughout the lifetime of the gaseous nebula. This research marks a substantial step forward in connecting both the dynamical and chemical aspects of planet formation.

Robinson, Sarah E.; Bodenheimer, P.

2010-10-01

2

Korean Kimchi Chemistry: A Multicultural Chemistry Connection  

ERIC Educational Resources Information Center

|Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

Murfin, Brian

2009-01-01

3

Korean Kimchi Chemistry: A Multicultural Chemistry Connection  

ERIC Educational Resources Information Center

Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

Murfin, Brian

2009-01-01

4

Cross-Connections of Chemistry  

NASA Astrophysics Data System (ADS)

We are in desperate need of qualified chemistry teachers. Are the teachers who have biology, physics, or some psychology degrees qualified to teach chemistry? Have they taken enough chemistry to be prepared to teach outside their degree field? If remediation is necessary, what courses should be required? Attracting pre-service science teachers to the study of pure chemistry is not an easy task when more attractive course offerings are available. Maybe we should concentrate on cross-training in-service teachers by providing appropriate graduate courses to encourage them and bring them into the family. Many teachers with degrees outside the traditional discipline of chemistry have adequate backgrounds in the applications of chemistry. Requiring hours of undergraduate education before they enter the hallowed halls of the chemistry building as graduate students only serves to discourage a large segment of in-service teachers who wish to broaden their perspective. The National Science Education Standards make a compelling argument for connecting and integrating science courses for practicing teachers (3). We are at the crossroads. At a time when we so desperately need qualified chemistry teachers, shouldn't we be more open in our graduate teaching programs, inviting those with degrees in other disciplines to start on a graduate degree without insisting on undergraduate or survey coursework first? Many potential chemical education graduate students have a background in chemistry--it is just known by another name.

Mason, Diana S.

2002-02-01

5

Connected Chemistry--Incorporating Interactive Simulations into the Chemistry Classroom.  

ERIC Educational Resources Information Center

|Describes a novel modeling and simulation package and assesses its impact on students' understanding of chemistry. Connected Chemistry was implemented inside the NetLogo modeling environment. Using Connected Chemistry, students employed problem -solving techniques characterized by stronger attempts at conceptual understanding and logical…

Stieff, Mike; Wilensky, Uri

2003-01-01

6

Strengthening conceptual connections in introductory chemistry courses  

Microsoft Academic Search

Both research on learning across a wide range of disciplines and common theories of learning recognize the importance of learning through making connections between new concepts to which one is exposed and existing cognitive structures or schemata. This paper considers examples of underappreciated cognitive connections that our experience has shown can facilitate students' learning of chemistry in the introductory course.

George M. Bodner

7

Crossing Levels and Representations: The Connected Chemistry (CC1) Curriculum  

ERIC Educational Resources Information Center

|Connected Chemistry (named CC1 to denote Connected Chemistry Chapter 1) is a computer-based environment for learning the topics of gas laws and kinetic molecular theory in chemistry. It views chemistry from an "emergent" perspective, how macroscopic phenomena result from the interaction of many submicroscopic particles. Connected Chemistry

Levy, Sharona T.; Wilensky, Uri

2009-01-01

8

Crossing Levels and Representations: The Connected Chemistry (CC1) Curriculum  

NASA Astrophysics Data System (ADS)

Connected Chemistry (named CC1 to denote Connected Chemistry Chapter 1) is a computer-based environment for learning the topics of gas laws and kinetic molecular theory in chemistry. It views chemistry from an "emergent" perspective, how macroscopic phenomena result from the interaction of many submicroscopic particles. Connected Chemistry employs agent-based models built in NetLogo (Wilensky, NetLogo, Northwestern University, Evanston, 1999a), embedded in scripts that structure and log the students' activities. A conceptual framework was developed to structure students' experiences and learning through exploring the models. The framework describes three spheres of knowledge (conceptual, symbolic and physical) and four forms of access to understanding the system (submicro, macro, mathematical and experiential). Activities were designed to help students build an integrated view of the chemical system, by focusing on understanding within each form of access, and promoting transitions between the spheres of knowledge. The macro-level descriptions were used to bridge between the three spheres and support these shifts. The conceptual framework for the Connected Chemistry curriculum is discussed and demonstrated. Further development directions are suggested.

Levy, Sharona T.; Wilensky, Uri

2009-06-01

9

Astrobiology and green chemistry: a new pedagogical connection  

NASA Astrophysics Data System (ADS)

Various pedagogical approaches are needed to introduce astrobiology into the chemistry curriculum. We are developing a new approach in which we connect green chemistry with astrobiology. Green chemistry is chemistry which is environmentally friendly. One obvious way for the organic chemistry to be environmentally friendly is to use water as solvent, instead of more toxic organic solvents. Another approach is to run so-called solventless reactions. For example, as the solid materials are mixed together, the melting point of the mixture is lower than the melting points of its individual components (the principle of the mixed-melting point). In some cases the entire mixture may melt upon mixing. The reactions would then occur in a viscous semi-solid state. An additional approach is to run the reactions by utilizing enzymes or man-made protein mimics as catalysts instead of toxic catalysts, such as those based on the transition metals. These and some other known examples of green chemistry have a great potential for astrobiology. The astrobiological reactions typically occur in water (e.g. prebiotic soup), in the solid mixtures (e.g. on the meteors), and may be catalyzed by various short peptides. The connection between the green chemistry principles and astrobiology represents a new pedagogical approach for infusion of astrobiology into the organic chemistry.

Kolb, Vera M.

2009-08-01

10

Flat zones filtering, connected operators, and filters by reconstruction  

Microsoft Academic Search

==== Abstract -- This paper deals with the notion of connected operators. Starting from the definition for operator acting on sets, it is shown how to extend it to operators acting on function. Typically, a connected operator acting on a function is a transformation that enlarges the partition of the space created by the flat zones of the functions. It

Philippe Salembier; Jean Serra

1995-01-01

11

Epidemic protection zones: centred on cases or based on connectivity?  

PubMed

When an exotic infectious disease invades a susceptible environment, protection zones are enforced. Historically, such zones have been shaped as circles of equal radius (ER), centred on the location of infected premises. Because the ER policy seems to assume that epidemic dissemination is driven by a similar number of secondary cases generated per primary case, it does not consider whether local features, such as connectivity, influence epidemic dispersal. Here we explored the efficacy of ER protection zones. By generating a geographically explicit scenario that mimicked an actual epidemic, we created protection zones of different geometry, comparing the cost-benefit estimates of ER protection zones to a set of alternatives, which considered a pre-existing connecting network (CN) - the road network. The hypothesis of similar number of cases per ER circle was not substantiated: the number of units at risk per circle differed up to four times among ER circles. Findings also showed that even a small area (of <115?km(2) ) revealed network properties. Because the CN policy required 20% less area to be protected than the ER policy, and the CN-based protection zone included a 23.8% greater density of units at risk/km(2) than the ER-based alternative, findings supported the view that protection zones are likely to be less costly and more effective if they consider connecting structures, such as road, railroad and/or river networks. The analysis of local geographical factors (contacts, vectors and connectivity) may optimize the efficacy of control measures against epidemics. PMID:22360843

Rivas, A L; Fasina, F O; Hammond, J M; Smith, S D; Hoogesteijn, A L; Febles, J L; Hittner, J B; Perkins, D J

2012-02-24

12

Ground water flow paths in relation to nitrogen chemistry in the near-stream zone  

Microsoft Academic Search

Interactions between ground water flow paths and water chemistry were studied in the riparian zone of a small headwater catchment near Toronto, Ontario. Significant variations in oxygen — 18 and chloride indicated the presence of distinct sources of water in the ground water flow system entering the near-stream zone. Shallow ground water at the upland perimeter of the riparian zone

Alan R. Hill

1990-01-01

13

Connecting Acids and Bases with Encapsulation... and Chemistry with Nanotechnology  

ERIC Educational Resources Information Center

|The features and the development of various new acids and bases activity sets that combines chemistry with nanotechnology are being described. These sets lead to the generation of many nanotechnology-based pharmaceuticals for the treatment of various diseases.|

Criswell, Brett

2007-01-01

14

Connecting Acids and Bases with Encapsulation... and Chemistry with Nanotechnology  

ERIC Educational Resources Information Center

The features and the development of various new acids and bases activity sets that combines chemistry with nanotechnology are being described. These sets lead to the generation of many nanotechnology-based pharmaceuticals for the treatment of various diseases.

Criswell, Brett

2007-01-01

15

A Review of Spatial Ability Literature, Its Connection to Chemistry, and Implications for Instruction  

ERIC Educational Resources Information Center

|Chemists and scientists use spatial abilities as part of the way they understand and communicate their subject areas. A review of the foundational research literature in spatial ability and its connections to chemistry as a field and chemical education research allows for the formulation of implications for teaching in chemistry. (Contains 7…

Harle, Marissa; Towns, Marcy

2011-01-01

16

Making Connections: Learning and Teaching Chemistry in Context  

Microsoft Academic Search

Even though several studies have reported positive attitudinal outcomes from context-based chemistry programs, methodological\\u000a obstacles have prevented researchers from comparing satisfactorily the chemistry-learning outcomes between students who experience\\u000a a context-based program with those who experience a content-driven program. In this narrative inquiry we are able to address\\u000a the question: how do the recalled experiences of a student and her teacher

Donna King; Alberto Bellocchi; Stephen M. Ritchie

2008-01-01

17

InChI: connecting and navigating chemistry  

PubMed Central

The International Chemical Identifier (InChI) has had a dramatic impact on providing a means by which to deduplicate, validate and link together chemical compounds and related information across databases. Its influence has been especially valuable as the internet has exploded in terms of the amount of chemistry related information available online. This thematic issue aggregates a number of contributions demonstrating the value of InChI as an enabling technology in the world of cheminformatics and its continuing value for linking chemistry data.

2012-01-01

18

An African Chemistry Connection: Simulating Early Iron Smelting.  

ERIC Educational Resources Information Center

|Presents a lesson plan that uses information about traditional African iron-smelting to highlight the scientific contributions of non-European cultures. Includes a laboratory activity on the reduction of metal oxides with a multicultural perspective that helps students grasp some of the chemistry concepts involved in smelting. (JRH)|

Murfin, Brian

1996-01-01

19

Exploring organic chemistry in planet-forming zones  

NASA Astrophysics Data System (ADS)

Context. Over the last few years, the chemistry of molecules other than CO in the planet-forming zones of disks is starting to be explored with Spitzer and high-resolution ground-based data. However, these studies have focused only on a few simple molecules. Aims: The aim of this study is to put observational constraints on the presence of more complex organic and sulfur-bearing molecules predicted to be abundant in chemical models of disks and to simulate high resolution spectra in view of future missions. Methods: High signal-to-noise ratio (S/N) Spitzer spectra of the near edge-on disks IRS 46 and GV Tau are used to search for mid-infrared absorption bands of various molecules. These disks are good laboratories because absorption studies do not suffer from low line/continuum ratios that plague emission data. Simple local thermodynamic equilibrium (LTE) slab models are used to infer column densities (or upper limits) and excitation temperatures. Results: Mid-infrared bands of HCN, C2H2 and CO2 are clearly detected toward both sources. The HCN and C2H2 absorption arises in warm gas with excitation temperatures of 400-700 K, whereas the CO2 absorption originates in cooler gas of ~250 K. Column densities and their ratios are comparable for the two sources. No other absorption features are detected at the 3? level. Column density limits of the majority of molecules predicted to be abundant in the inner disk - C2H4, C2H6, C6H6, C3H4, C4H2, CH3, HNC, HC3N, CH3CN, NH3 and SO2 - are determined and compared with disk models. Conclusions: The inferred abundance ratios and limits with respect to C2H2 and HCN are roughly consistent with models of the chemistry in high temperature gas. Models of UV irradiated disk surfaces generally agree better with the data than pure X-ray models. The limit on NH3/HCN implies that evaporation of NH3-containing ices is only a minor contributor. The inferred abundances and their limits also compare well with those found in comets, suggesting that part of the cometary material may derive from warm inner disk gas. The high resolution simulations show that future instruments on the James Webb Space Telescope (JWST), the Extremely Large Telescopes (ELTs), the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) can probe up to an order of magnitude lower abundance ratios and put important new constraints on the models, especially if pushed to high S/Ns. Appendices are available in electronic form at http://www.aanda.org

Bast, J. E.; Lahuis, F.; van Dishoeck, E. F.; Tielens, A. G. G. M.

2013-03-01

20

Identifying fracture-zone geometry using simulated annealing and hydraulic-connection data  

Microsoft Academic Search

A new approach is presented to condition geostatistical simulation of high-permeability zones in fractured rock to hydraulic-connection data. A simulated-annealing algorithm generates three-dimensional (3-D) realizations conditioned to borehole data, inferred hydraulic connections between packer-isolated borehole intervals, and an indicator (fracture zone or background-K bedrock) variogram model of spatial variability. We apply the method to data from the U.S. Geological Survey

Frederick D. Day-Lewis; Paul A. Hsieh; Steven M. Gorelick

2000-01-01

21

Shear instability of panel zone in beam-to-column connections  

Microsoft Academic Search

In this paper, the problem of shear buckling in the panel zone of beam-to-column connections is examined. In particular, following the application of the shear buckling theory for rectangular plates, both in the elastic and in the plastic field, and a critical review of American and European provisions for panel zones, a parametric FEM analysis using ABAQUS Code is carried

Giuseppe Brandonisio; Antonio De Luca; Elena Mele

2011-01-01

22

Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

|We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure…

Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

2008-01-01

23

Physical conditions and molecular chemistry of the Central Molecular Zone  

NASA Astrophysics Data System (ADS)

We discuss the physical conditions of the different kineniatical components of the Central Molecular Zone. In particular we compare the properties of the clouds moving with in elongated orbits along the Galactic bar with those of the well-known Galactic center ring (GCR) clouds (Sgr A, Sgr B2,...). We show that all the components contain dense clouds that can withstand the tidal shear. The SiO abundance in the clouds with non-circular velocities is high (~ 10-8), in perfect agreement with that of the GCR clouds. We discuss the role of the UV radiation and C-shocks in the heating of the neutral gas and the high abundances of some molecules like SiO. The SiO emission in the clouds moving in elongated trajectories is probably due to the cloud collisions expected in the inner regions of a bar.

Rodríguez-Fernández, Nemesio J.

2006-12-01

24

The Connection between Success in a Freshman Chemistry Class and a Student's Jungian Personality Type  

NASA Astrophysics Data System (ADS)

This paper explores the connection between a student's performance in a freshman chemistry class and his or her personality type. Performance was gauged by the final percentage grade earned in class and personality type was based on Carl G. Jung's personality typology as assessed by the Myers-Briggs Type Indicator (MBTI). Performance and personality type were correlated using ANOVA statistics. The results show that only one of the 16 personality types had a class average that was significantly higher than 14 of the other 15 types. The lowest-scoring type was also significantly lower than 3 other personality types. This research shows that characteristics of personality types may be a basis for assisting or deterring success in a general chemistry class. Data on the personality types of 23 chemistry professors suggest that a success bias may be amplified by similar personality traits in the instructors.

Clark, Gale J.; Riley, Wayne D.

2001-10-01

25

Testing early life connectivity using particle tracking simulations and otolith chemistry  

NASA Astrophysics Data System (ADS)

Large-scale circulation may structure populations of oceanic fish, and hence distributions of chemistry in their otoliths. We applied a combination of Lagrangian modelling and otolith chemistry of Scotia Sea icefish (Chaenocephalus aceratus), a species with a long pelagic larval phase found along the Antarctic Circumpolar Current, to test connectivity previously predicted between the Antarctic Peninsula and South Georgia. Material laid down in the otolith nucleus during early life showed evidence of heterogeneity between sampling areas on the northern Antarctic Peninsula, whereas similar nucleus chemistry at sampling areas off South Georgia suggested a discrete, locally-recruiting population, consistent with observed larval assemblages. Strong evidence of a population boundary discounted hypotheses of early life connectivity between the two regions. This was consistent with particle simulations of the large-scale circulation, which predicted that particles released deep on the Antarctic Peninsula shelf during late winter, corresponding to hatching of icefish larvae from benthic nests, are transported close to the ACC southern boundary, missing South Georgia but following trajectories along the south Scotia Ridge. Used together, the two techniques promise an innovative approach to generate and test predictions, and resolve early dispersal and connectivity related to the physical circulation of oceanic systems.

Ashford, Julian; Fach, Bettina A.; La Mesa, Mario; Jones, Christopher; Everson, Inigo

2010-05-01

26

Collboration: Interfacial Soil Chemistry of Radionuclides in the Unsaturated Zone  

SciTech Connect

The principal goal of this project was to assess the molecular nature and stability of radionuclide immoblization during weathering reactions in bulk Hanford sediments and their high surface area clay mineral constituents. We focused on the unique aqueous geochemical conditions that are representative of waste-impacted locations in the Hanford site vadose zone; high ionic strength, high pH and high Al concentrations. The specific objectives of the work were to measure the coupling of clay mineral weathering and contaminant uptake kinetics of Cs, Sr and I; determine the molecular structure of contaminant binding sites and their change with weathering time during and after exposure to synthetic tank waste leachate; establish the stability of neoformed weathering products and their sequestered contaminbants upon exposure of the solids to more natural soil solutaions afer remofal of the caustic waste source; and integrate macroscopic, microscopic and spectroscopic data to distinguish labile from non-labile contaminant binding environments, including their dependence on system composition and weathering time.

Karl T. Mueller; Don Chorover; Peggy O'Day; R. Jeff Serne; Garry Crosson; Geoffrey Bowers; Nelson Rivera

2006-12-11

27

Supra-subduction zone (SSZ) ophiolites: the Fore-arc connection (Invited)  

NASA Astrophysics Data System (ADS)

Ophiolites are distinct assemblages of submarine volcanic rocks and plutonic rocks that include cumulate dunite, wehrlite, and gabbro, as well as isotropic gabbro and diorite, and peridotite tectonite, representing the underlying refractory mantle. They were originally thought to represent oceanic crust formed at mid-oceanic spreading centers, but their connection with island arcs has become increasingly apparent ever since it was proposed by Miyashiro (1973). Recognition that ophiolites are not normal arc assemblages, but form during unique, transient episodes of arc formation, has led to the concept of supra-subduction zone ophiolites (Pearce, 1984). SSZ ophiolites display a consistent development history from birth through death that implies a common origin and evolution in response to systematic, non-random processes (Shervais 2001). A review of modern volcanic rocks formed at mid-ocean ridges and back-arc basins shows that they have a limited range in major element compositions, and trace element systematics that range from depleted (“normal”) to enriched MORB, in which ratios of fluid-mobile LFS elements to fluid-immobile HFS elements are relatively constant. In contrast, volcanic rocks formed within regionally-extended fore-arcs (which may also form the basement of later arc complexes) have wider range in major element compositions and trace element systematics that are depleted in the HFS elements and enriched in fluid-mobile LFS elements (Metcalf and Shervais 2008). Most ophiolite volcanic suites are dominated by major and trace element systematics that are identical to those displayed by fore-arc volcanic suites, including the occurrence of boninites, which are only found within forearc settings. These systematics are consistent with fluid-enrichment of the mantle source region that had seen a prior extreme melt depletion event. Some ophiolites display more complex relations, with both SSZ and MORB or BAB-like compositions, but the SSZ components are generally dominant. These observations of volcanic rock chemistry are reinforced by recent studies of the mantle peridotite tectonites that underlie ophiolites. These studies show that ophiolite tectonites are strongly depleted in HFS and rare earth elements, requiring extensive melt extraction, and enriched in fluid-mobile elements, requiring a significant fluid flux that can only be sustained in a supra-subduction zone setting. This conclusion is enforced by recent isotopic studies, which document subduction-enriched isotopic compositions of Sr and Pb in SSZ ophiolites, and by ICP-MS studies of fluid mobile elements in relict pyroxene, which document enrichment in all fluid mobile elements. We conclude that ophiolites provide an analogue to modern fore-arc settings, and that their position in the upper plate of a subduction-zone leads to their preferential emplacement by obduction onto passive continental margins, or by accretionary uplift along continually active margins.

Shervais, J. W.; Metcalf, R. V.

2009-12-01

28

Investigating macroscopic, submicroscopic, and symbolic connections in a college-level general chemistry laboratory  

NASA Astrophysics Data System (ADS)

Explanations of chemical phenomena rely on understanding the behavior of submicroscopic particles. Because this level is "invisible," it is described using symbols such as models, diagrams and equations. For this reason, students often view chemistry as a "difficult" subject. The laboratory offers a unique opportunity for the students to experience chemistry macroscopically as well as symbolically. The purpose of this investigation was to determine how chemistry lab students explained chemical phenomenon on the macroscopic, submicroscopic, and representational/symbolic level. The participants were undergraduate students enrolled in an introductory level general chemistry lab course. Students' background information (gender, the number of previous chemistry courses), scores on final exams, and final average for the course were collected. Johnstone's triangle of representation guided the design and implementation of this study. A semi-structured interview was also conducted to bring out student explanations. The questionnaires required students to draw a molecule of water, complete acid base reaction equations, represent, submicroscopically, the four stages of an acid-base titration, and provide definitions of various terms. Students were able represent the submicroscopic level of water. Students were not able to represent the submicroscopic level of the reaction between an acid and a base. Students were able to represent the macroscopic level of an acid base reaction. Students were able to symbolically represent the reaction of an acid and a base. These findings indicate that students can use all three levels of chemical representation. However, students showed an inability to connect the levels in relation to acid-base chemistry. There was no relationship between a student's ability to use the levels and his or her final score in the course.

Thadison, Felicia Culver

29

Associations between water chemistry and fish community composition: a comparison between isolated and connected lakes in northern Sweden  

Microsoft Academic Search

SUMMARY 1. The correlation between water chemistry, physical variables and fish community composition was examined in 40 small (£30 ha) coastal lakes in northern Sweden. Twenty of the 40 lakes were isolated from other water bodies and 20 were connected to the Baltic Sea. Lakes were fished in summer, using three different methods. Water chemistry was sampled in late winter

JOHANNA OHMAN; I SHI; GORAN E NGLUND; A NDREAS B LOM; EMMA L INDGREN; H JALMAR L AUDON

30

Cortical Connections of Functional Zones in Posterior Parietal Cortex and Frontal Cortex Motor Regions in New World Monkeys  

PubMed Central

We examined the connections of posterior parietal cortex (PPC) with motor/premotor cortex (M1/PM) and other cortical areas. Electrical stimulation (500 ms trains) delivered to microelectrode sites evoked movements of reach, defense, and grasp, from distinct zones in M1/PM and PPC, in squirrel and owl monkeys. Tracer injections into M1/PM reach, defense, and grasp zones showed dense connections with M1/PM hand/forelimb representations. The densest inputs outside of frontal cortex were from PPC zones. M1 zones were additionally connected with somatosensory hand/forelimb representations in areas 3a, 3b, and 1 and the somatosensory areas of the upper bank of the lateral sulcus (S2/PV). Injections into PPC zones showed primarily local connections and the densest inputs outside of PPC originated from M1/PM zones. The PPC reach zone also received dense inputs from cortex caudal to PPC, which likely relayed visual information. In contrast, the PPC grasp zone was densely connected with the hand/forelimb representations of areas 3a, 3b, 1, and S2/PV. Thus, the dorsal parietal–frontal network involved in reaching was preferentially connected to visual cortex, whereas the more ventral network involved in grasping received somatosensory inputs. Additional weak interlinks between dissimilar zones (e.g., PPC reach and PPC grasp) were apparent and may coordinate actions.

Stepniewska, Iwona; Kaas, Jon H.

2011-01-01

31

Dynamics of plasmodesmal connectivity in successive interfaces of the cambial zone  

Microsoft Academic Search

Frequency, density and branching of plasmodesmata were counted in successive tangential and transverse walls in the cambial\\u000a zone of tomato stems in order to examine development of the plasmodesmal network in a chronological order. Coincident with\\u000a progress of cell development, plasmodesmal connectivity increased, both at the xylem- and phloem-side. In transverse walls,\\u000a the number of secondary plasmodesmata enhanced considerably. The

Katrin Ehlers; Aart J. E. van Bel

2010-01-01

32

Thalamic and extrathalamic connections of the dysgranular unresponsive zone in the grey squirrel (Sciurus carolinensis).  

PubMed

The connections of the cortical dysgranular "unresponsive zone" (UZ) (Sur et al.: J. Comp. Neurol. 179:425-450, '78) in the grey squirrel were studied with horseradish peroxidase and autoradiographic techniques. The results of these experiments show that the major subcortical connections of the unresponsive zone are in large part reciprocal. Connections are distributed within the thalamus in a poorly defined region including restricted portions of several nuclei that lie along the rostral, dorsal, and caudal borders of the ventral posterior nucleus. Additional thalamic connections of the UZ terminate in the reticular nucleus and are reciprocally related to the paralaminar and central median nuclei. Extrathalamic terminations were observed in the zona incerta, the intermediate and deep layers of the superior colliculus, the red nucleus, and several subdivisions of the pontine nuclei. The similarity between the pattern of subcortical connections of the UZ in the grey squirrel and patterns reported for the parietal septal region in rats (Chapin and Lin: J. Comp. Neurol. 229:199-213, '84) and for area 3a in primates (Friedman and Jones: J. Neurophysiol. 45:59-85, '81), suggests that the UZ in the grey squirrel may represent a counterpart of at least part of area 3a as described in primates. The results are further discussed with respect to a possible role of the thalamus in control or modulation of interhemispheric circuits and of the UZ in the modulation of nociceptive and kinesthetic pathways through the thalamus. Finally, the term parietal dysgranular cortex (PDC) is proposed as an alternative to denote the region currently called the unresponsive zone. PMID:2477399

Gould, H J; Whitworth, R H; LeDoux, M S

1989-09-01

33

Using elemental chemistry of fish otoliths to determine connectivity between estuarine and coastal habitats  

NASA Astrophysics Data System (ADS)

Connectivity between estuarine and coastal populations is poorly understood but fundamental to the study of population dynamics, as well as the design of effective conservation and management strategies. Naturally occurring elemental signatures (or composition) in the otoliths of fish are an ideal natural tag due to the metabolic inertness of otoliths, continuous growth including daily increments and incorporation of elements that are influenced by environmental variables. In this paper, I review the use of otolith chemistry to determine connectivity between estuarine and coastal habitats focusing on assumptions of using elemental signatures as natural tags, consequences of violating these assumptions and finally providing examples of the application of natural tags to determine connectivity. As a first step to determining connectivity, it is important to determine whether fish residing in different estuaries do in fact have different elemental signatures. Spatial differences must be determined for each species of interest since variability has been found between species collected from the same location. For retrospective determination of origins of fish, it is also necessary to ensure either that there is no temporal variation at both the small (e.g. among months within a year) and large scale (e.g. among years) or to match adults to the appropriate year class of juveniles. In addition, fish should be collected from all possible source groups contributing to the group mixture. The majority of studies that show connectivity between estuarine and open coastal populations using otolith chemistry have determined the contribution of different habitats or estuaries to the adult population, although natal homing has also been examined.

Gillanders, B. M.

2005-07-01

34

Introductory college chemistry students' understanding of stoichiometry: Connections between conceptual and computational understandings and instruction  

NASA Astrophysics Data System (ADS)

Previous research has shown a gap between chemistry students' conceptual and computational understandings of chemistry topics such as gas laws, equilibrium, and reactions. This qualitative study examined the conceptual and computational understandings of stoichiometry of college students enrolled in a large lecture Introductory Chemistry course. Factors that might influence students' understandings were examined to determine their influence. Possible influential factors examined included students' prior coursework, and their current chemistry instruction. Instruction on stoichiometry was examined through classroom observations, an instructor interview, and review of the course resources. Course exams and out-of-class assignments were also examined for their influence on students. Student volunteers (n = 6) were interviewed to gauge their understanding of stoichiometry. Students' understanding was assessed through tasks that included a card sort, solving conceptual and computational problems, drawing representations of reactions, and answering questions concerning their philosophy of learning chemistry. Results indicated that students had an acceptable understanding of the particulate nature of matter but did not apply this knowledge to problem solving. The students were most comfortable solving computational problems where they could apply algorithms learned from their instructor. The students also applied algorithms in answering conceptual problems. There appeared to be a connection between the students' conceptual structures of stoichiometry and their ability to solve computational problems. The lack of conceptual questions in assessment appeared to be a major contributing factor in the students' lack of conceptual understanding because the students discounted the importance of learning aspects of stoichiometry that were not included on exams. Other contributing factors included the computational focus of instruction on limiting reactant problems, textbook presentation, and student exercises.

Wolfer, Adam Joseph

35

Theoretical study of multicomponent continuous countercurrent chromatography based on connected 4-zone units.  

PubMed

Continuous countercurrent or simulated moving bed (SMB) chromatography is a well-established separation technology. Conventional processes are based on four zones which fulfil distinct functions in order to split a feed into two fractions. Frequently there is an interest in isolating a target component out of a feed mixture containing more than two components. Modifications of the classical SMB process are required to solve this task. In the last years several concepts exploiting more than four zones have been suggested. To analyse these concepts the equilibrium theory has been frequently applied, neglecting all kinetic effects. It is the purpose of this paper to apply an equilibrium stage model in order to describe the performance of a combination of two or three 4-zone true moving bed units which are connected in series or integrated into 8- or 12-zone true moving bed units. The performance of such units is evaluated with respect to their potential to continuously separate ternary or quaternary mixtures. The analysis is based on the assumption of linear adsorption isotherms. An important aspect is the introduction of additional purge streams required for a successful operation of integrated 8- and 12-zone units. PMID:16759666

Kessler, Lars Christian; Seidel-Morgenstern, Andreas

2006-06-06

36

Spatial and temporal variation in the natal otolith chemistry of a Hawaiian reef fish: prospects for measuring population connectivity  

Microsoft Academic Search

One of the most compelling unanswered questions in marine ecology is the extent to which local populations are connected via larval exchange. Recent work has suggested that variation in the chemistry of otoliths (earstones) of fishes may function as a natural tag, potentially allowing investigators to determine sources of individual larvae and esti- mate larval connectivity. We analyzed the spatial

Benjamin I. Ruttenberg; Scott L. Hamilton; Robert R. Warner

2008-01-01

37

Hydrologic connectivity increases denitrification in the hyporheic zone and restored floodplains of an agricultural stream  

NASA Astrophysics Data System (ADS)

Stream ecotones, specifically the lateral floodplain and subsurface hyporheic zone, can be important sites for nitrogen (N) removal via denitrification, but their role in streams with constructed floodplains has not been examined. We studied denitrification in the hyporheic zone and floodplains of an agriculturally influenced headwater stream in Indiana, USA, that had floodplains added as part of a "two-stage ditch" restoration project. To examine the potential for N removal in the hyporheic zone, we seasonally measured denitrification rates and nitrate concentrations by depth into the stream sediments. We found that nitrate concentration and denitrification rates declined with depth into the hyporheic zone, but denitrification was still measureable to a depth of at least 20 cm. We also measured denitrification rates on the restored floodplains over the course of a flood (pre, during, and post-inundation), and also compared denitrification rates between vegetated and non-vegetated areas of the floodplain. We found that floodplain denitrification rates increased over the course of a floodplain inundation event, and that the presence of surface water increased denitrification rates when vegetation was present. Stream ecotones in midwestern, agriculturally influenced streams have substantial potential for N removal via denitrification, particularly when they are hydrologically connected with high-nitrate surface water.

Roley, Sarah S.; Tank, Jennifer L.; Williams, Maureen A.

2012-09-01

38

Introductory College Chemistry Students' Understanding of Stoichiometry: Connections between Conceptual and Computational Understandings and Instruction.  

ERIC Educational Resources Information Center

|Many studies of college chemistry students have found a gap between students' success in solving computational chemistry problems and their success in solving conceptual chemistry problems. This paper examines college students' understanding of the concept of stoichiometry, the particulate nature of matter, and chemistry problem solving. This…

Wolfer, Adam J.; Lederman, Norman G.

39

Pore fluid chemistry of the North Anatolian Fault Zone in the Sea of Marmara: A diversity of sources and processes  

Microsoft Academic Search

As part of the 2007 Marnaut cruise in the Sea of Marmara, an investigation of the pore fluid chemistry of sites along the Main Marmara Fault zone was conducted. The goal was to define the spatial relationship between active faults and fluid outlets and to determine the sources and evolution of the fluids. Sites included basin bounding transtensional faults and

M. D. Tryon; P. Henry; M. N. Ça?atay; T. A. C. Zitter; L. Géli; L. Gasperini; P. Burnard; S. Bourlange; C. Grall

2010-01-01

40

Volatile and N isotope chemistry of the Molucca Sea collision zone: Tracing source components along the Sangihe Arc, Indonesia  

Microsoft Academic Search

Volcanic gases are sensitive indicators of subduction processes and are used to evaluate the contributions from various source components. Nitrogen isotope systematics in particular are a valuable tool for determining the fate of organic matter in subduction zones. We present the first arc-wide survey of trace gas chemistry and nitrogen isotope variations from the Sangihe Arc of northeastern Indonesia, where

Laura E. Clor; Tobias P. Fischer; David R. Hilton; Zachary D. Sharp; Udi Hartono

2005-01-01

41

Hydrological connectivity of upland-riparian zones in agricultural catchments: Implications for runoff generation and nitrate transport  

NASA Astrophysics Data System (ADS)

This paper addresses the issue of hydrological connectivity between discrete units of the landscape, notably, upland and riparian zones, and its implication for runoff generation and chemical transport. It presents results based on a field experiment carried in Susannah Brook catchment in Western Australia, during which measurements of relevant physical and chemical parameters were carried out using a sampling strategy that enabled us to capture the complete cycle of hydrological connection and disconnection over the entire hillslope. The results show that the upland and riparian zones respond to rainfall events almost independently and differently, and remain disconnected from each other for much of the year. During a 2 3 month period in mid-winter, however, a shallow groundwater system becomes established all the way across the hillslope, providing a direct hydrological connection between the two zones, enabling not only down-slope transport of fresh water but also nitrates that had previously accumulated in the upland zone. Associated with the establishment of connectivity is a sharp increase in the hydraulic gradient that drives shallow subsurface flow to the stream. These results have important implications for the modelling of runoff generation and nutrient export. The lack of connectivity for much of the year precludes the use of models that assume that the shallow subsurface flow system is connected all the way up the slope, and that hydraulic gradient is equal to local topographic gradient. The findings relating to hydrological connectivity also have important ramifications for Cl- and NO3- transport and export. The complex internal dynamics of flow, transport and reaction, and their dependence on hydraulic connectivity, must be explicitly captured if we are to develop predictive models that remain accurate as well as internally consistent.

Ocampo, Carlos J.; Sivapalan, Murugesu; Oldham, Carolyn

2006-12-01

42

Vygotskian-based grouping: Utilizing the zone of proximal development in a chemistry laboratory  

NASA Astrophysics Data System (ADS)

A large portion of any science major's curriculum utilizes laboratories. Many of these laboratories now incorporate cooperative learning as a result of studies attesting to its beneficial effects. However, little attention has been given to the composition of those groups, specifically at post-secondary education institutes. We have therefore investigated the effectiveness of a grouping technique based on the theories of L. S. Vygotsky and his construct of the zone of proximal development (ZPD) in the context of an undergraduate general chemistry laboratory course at The University of Texas at Austin. All students were responsible for the completion of a short, 11 question, pre-quiz. Depending on their respective classes, students were grouped either according to the ZPD-scheme, based on pre-quiz scores, or randomly, regardless of pre-quiz score. Achievement of the students in each of the two groups was compared in order to determine grouping effectiveness. This study was carried out for 3 semesters (spring 2003, spring 2004, and fall 2004) under two different instructors. Overall, results indicate that grouping according to the ZPD-scheme revealed higher student achievement versus random grouping. Moreover, students scoring low and average on pre-quizzes benefited far more from this grouping method than higher scoring students. The protocol for implementing this grouping scheme is straightforward and is discussed in detail.

Briggle, Justin David

43

Connectivity  

ERIC Educational Resources Information Center

Connectivity has dramatically changed the landscape of higher education IT. From "on-demand" services for net-gen students and advanced eLearning systems for faculty, to high-performance computing grid resources for researchers, IT now provides more networked services than ever to connect campus constituents to each other and to the world.…

Grush, Mary, Ed.

2006-01-01

44

Connecting Geometry and Chemistry: A Three-Step Approach to Three-Dimensional Thinking  

ERIC Educational Resources Information Center

|A three-step active-learning approach is described to enhance the spatial abilities of general chemistry students with respect to three-dimensional molecular drawing and visualization. These activities are used in a medium-sized lecture hall with approximately 150 students in the first semester of the general chemistry course. The first activity…

Donaghy, Kelley J.; Saxton, Kathleen J.

2012-01-01

45

Chemistry  

NSDL National Science Digital Library

Finds ChemEd DL resources related to the sections of the General Chemistry textbook, Chemistry, by Kenneth W. Whitten, Raymond E. Davis, M. Larry Peck, George G. Stanley published by Brooks/Cole, 2010.

46

DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River  

USGS Publications Warehouse

Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ???3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss. Biologically available organic carbon controlled biotic nitrate retention during hillslope transport. In the alluvial riparian zone (Zone 2) biologically available organic carbon controlled nitrate depletion although processing of both ambient and amended nitrate was faster during the summer than winter. In the hyporheic zone (Zone 3) and stream surface water (Zone 4) DIN retention was primarily controlled by temperature. Perfusion core studies using hyporheic sediment indicated sufficient organic carbon in bed sediments to retain ground water DIN via coupled nitrification-denitrification. Numerical simulations of seasonal hyporheic sediment nitrification-denitrification rates from perfusion cores adequately predicted surface water ammonium but not nitrate when compared to 5 years of monthly field data (1989-93). Mass balance studies in stream surface water indicated proportionally higher summer than winter N retention. Watershed DIN retention was effective during summer under the current land use of intermittently grazed pasture. However, more intensive land use such as row crop agriculture would decrease nitrate retention efficiency and increase loads to surface water. Understanding DIN retention capacity throughout the system, including special channel features such as sloughs, wetlands and floodplains that provide surface water-ground water connectivity, will be required to develop effective nitrate management strategies. ?? 2007 American Water Resources Association.

Triska, F. J.; Duff, J. H.; Sheibley, R. W.; Jackman, A. P.; Avanzino, R. J.

2007-01-01

47

Mineral chemistry and zoning in eclogite inclusions from Colorado Plateau diatremes  

Microsoft Academic Search

Eclogite inclusions from kimberlitic diatremes on the Colorado Plateau contain intricately zoned garnet and pyroxene and unusual textures. Detailed electron microprobe traverses for a clinopyroxene-garnet-phengite-lawsonite-rutile assemblage show garnet zoning from Alm69Gr21Py10 (core) to Alm61Gr13Py26 (rim) and pyroxene zoning from Jd50 (core) through Jd77 to Jd55 (rim). Pyroxene cores are Cr-rich in another rock. Sharp compositional discontinuities and zoning reversals are

Douglas Smith; M. Zientek

1979-01-01

48

Relation Between Connected Patterns in Heterogeneous Soil Parameter Fields and Solute Transport Models in the Unsaturated Zone  

NASA Astrophysics Data System (ADS)

Transport of solutes, such as agrochemicals, in the vadose zone is mostly described by an advection-dispersion equation, where the flow velocity of water in is described by the Richards equation. Soil is in reality highly heterogeneous, so the hydraulic parameters vary in space and their detailed structure is unknown. Heterogeneity of hydraulic soil parameters has a strong influence on flow and transport processes. As an example, it determines dispersion of solute concentration. As water and mass fluxes usually have to be predicted on length scales much larger than the typical length scales of heterogeneities, flow and transport models have to be upscaled to predict spatial averages of state variables (water content or solute concentration). Upscaled models for flow and transport in aquifers are quite well established. In the unsaturated zone, where variances of hydraulic parameters can be extremely high, assumptions such as smoothly varying, moderately heterogeneous hydraulic parameter fields can often not be made to derive upscaled models. Heterogeneity of soil is usually captured by modeling hydraulic parameters as correlated random fields. These fields are mostly directly or indirectly assumed to be multi-Gaussian. This implies that no information is used upon whether a certain parameter range is spatially connected or forms isolated clusters. However, connectivity has been found to have a strong influence on parameters of upscaled flow models, in particular if the variance of parameters is high. In this presentation, the influence of connected structures of heterogeneous hydraulic parameter fields on upscaled solute transport models in the vadose zone will be discussed. Upscaled models are derived using homogenization theory. The models are analyzed for different configurations of connected and isolated parameter ranges and for different parameter contrasts. Homogenization theory is based on an expansion of the flow- and transport equation in terms of the ratio between typical large length scale (for example the medium size) and typical small length scale (for example the length scale of a macroscopic representative elementary volume). By analyzing different parameter contrasts, quantified in terms of the expansion parameter, it can be demonstrated that, for example, the occurrence of non-equilibrium effects in the upscaled model depends crucially on the information about connectivity of different parameter ranges. Besides the type of upscaled model, also the effective model parameters depend on this type of information and can deviate significantly from effective parameters derived under the assumption that parameter fields are multi-Gaussian. The influence of connectivity of parameter fields on upscaled transport models in the vadose zone will be demonstrated with different multi-Gaussian and non-Gaussian test fields.

Neuweiler, I.; Nowak, W.

2007-12-01

49

For the Love of Learning Science: Connecting Learning Orientation and Career Productivity in Physics and Chemistry  

ERIC Educational Resources Information Center

|An individual's motivational orientation serves as a drive to action and can influence their career success. This study examines how goal orientation toward the pursuit of a graduate degree in physics and chemistry influences later success outcomes of practicing physicists and chemists. Two main categories of goal orientation are examined in this…

Hazari, Zahra; Potvin, Geoff; Tai, Robert H.; Almarode, John

2010-01-01

50

Investigating Macroscopic, Submicroscopic, and Symbolic Connections in a College-Level General Chemistry Laboratory  

ERIC Educational Resources Information Center

|Explanations of chemical phenomena rely on understanding the behavior of submicroscopic particles. Because this level is "invisible," it is described using symbols such as models, diagrams and equations. For this reason, students often view chemistry as a "difficult" subject. The laboratory offers a unique opportunity for the students to…

Thadison, Felicia Culver

2011-01-01

51

Connecting scientific research and classroom instruction: Developing authentic problem sets for the undergraduate organic chemistry curriculum  

NASA Astrophysics Data System (ADS)

Reform efforts in science education have called for instructional methods and resources that mirror the practice of science. Little research and design methods have been documented in the literature for designing such materials. The purpose of this study was to develop problems sets for sophomore-level organic chemistry instruction. This research adapted an instructional design methodology from the science education literature for the creation of new curricular problem sets. The first phase of this study was to establish an understanding of current curricular problems in sophomore-level organic chemistry instruction. A sample of 792 problems was collected from four organic chemistry courses. These problems were assessed using three literature reported problem typologies. Two of these problem typologies have previously been used to understand general chemistry problems; comparisons between general and organic chemistry problems were thus made. Data from this phase was used to develop a set of five problems for practicing organic chemists. The second phase of this study was to explore practicing organic chemists' experiences solving problems in the context of organic synthesis research. Eight practicing organic chemists were interviewed and asked to solve two to three of the problems developed in phase one of this research. These participants spoke of three problem types: project level, synthetic planning, and day-to-day. Three knowledge types (internal knowledge, knowledgeable others, and literature) were used in solving these problems in research practice and in the developed problems. A set of guiding factors and implications were derived from this data and the chemistry education literature for the conversion of the problems for practicing chemists to problems for undergraduate students. A subsequent conversion process for the five problems occurred. The third, and last phase, of this study was to explore undergraduate students' experiences solving problems in the classroom. Eight undergraduate students from four different organic chemistry courses were interviewed and asked to solve three of the problems converted at the end of phase two. Data from these interviews were used to understand the types, methods, and knowledge uses by undergraduate students in the problem-solving process. Data from all three phases were used to assert seven ideas for the development of problems for undergraduate students.

Raker, Jeffrey R.

52

Chemistry  

NSDL National Science Digital Library

Chemistry is the scientific study of matter and its interaction with other matter and with energy. It is the branch of natural science that deals with the composition of substances and their properties and reactions.

K-12 Outreach,

53

Archean inheritance in zircon from late Paleozoic granites from the Avalon zone of southeastern New England: an African connection  

USGS Publications Warehouse

In southeastern New England the Narragansett Pier Granite locally intrudes Carboniferous metasedimentary rocks of the Narragansett basin, and yields a monazite UPb Permian emplacement age of 273 ?? 2 Ma. Zircon from the Narragansett Pier Granite contains a minor but detectable amount of an older, inherited component, and shows modern loss of lead. Zircon from the late-stage, aplitic Westerly Granite exhibits a more pronounced lead inheritance -permitting the inherited component to be identified as Late Archean. Such old relict zircon has not been previously recognized in Proterozoic to Paleozoic igneous rocks in New England, and may be restricted to late Paleozoic rocks of the Avalon zone. We suggest that the Archean crustal component reflects an African connection, in which old Archean crust was underplated to the Avalon zone microplate in the late Paleozoic during collision of Gondwanaland with Avalonia. ?? 1987.

Zartman, R. E.; Don, Hermes, O.

1987-01-01

54

Carbonate chemistry in the coastal zone responds more strongly to eutrophication than to ocean acidification  

Microsoft Academic Search

The accumulation of anthropogenic CO2 in the ocean has altered carbonate chemistry in surface waters since pre-industrial times and is expected to continue to do so in the coming centuries. Changes in carbonate chemistry can modify the rates and fates of marine primary production and calcification. These modifications can in turn lead to feed-backs on increasing atmospheric CO2. We show

Alberto V. Borges; Gypens Nathalie

2010-01-01

55

APPLICATIONS OF MOLECULAR CONNECTIVITY INDEXES AND MULTIVARIATE ANALYSIS IN ENVIRONMENTAL CHEMISTRY  

EPA Science Inventory

The authors have developed a data matrix of 90 variables calculated from molecular connectivity indices for 19,972 chemicals in the Toxic Substance Control Act (TSCA) inventory of industrial chemicals. The first three principal components convey generalized information on chemica...

56

Confirmation of functional zones within the human subthalamic nucleus: Patterns of connectivity and sub-parcellation using diffusion weighted imaging  

PubMed Central

The subthalamic nucleus (STN) is a small, glutamatergic nucleus situated in the diencephalon. A critical component of normal motor function, it has become a key target for deep brain stimulation in the treatment of Parkinson's disease. Animal studies have demonstrated the existence of three functional sub-zones but these have never been shown conclusively in humans. In this work, a data driven method with diffusion weighted imaging demonstrated that three distinct clusters exist within the human STN based on brain connectivity profiles. The STN was successfully sub-parcellated into these regions, demonstrating good correspondence with that described in the animal literature. The local connectivity of each sub-region supported the hypothesis of bilateral limbic, associative and motor regions occupying the anterior, mid and posterior portions of the nucleus respectively. This study is the first to achieve in-vivo, non-invasive anatomical parcellation of the human STN into three anatomical zones within normal diagnostic scan times, which has important future implications for deep brain stimulation surgery.

Lambert, Christian; Zrinzo, Ludvic; Nagy, Zoltan; Lutti, Antoine; Hariz, Marwan; Foltynie, Thomas; Draganski, Bogdan; Ashburner, John; Frackowiak, Richard

2012-01-01

57

Thermal regime in the central Alpine Fault zone, New Zealand: Constraints from microstructures, biotite chemistry and fluid inclusion data  

NASA Astrophysics Data System (ADS)

The thermal state within plate boundary fault zones is likely to influence the dimensions of large co-seismic fault ruptures, and strain localisation in underlying mylonitic shear zones. Vein microstructures, biotite chemistry and fluid inclusion data offer new insights into the thermal structure of the mylonitic shear zone down dip of the Alpine Fault, the main Pacific-Australian plate boundary structure through southern New Zealand.Quartz veins within the fault rocks were formed and deformed at temperatures ranging from > 500 °C to immediately above that of the brittle-viscous transition (˜ 325 °C), illustrating that fluids are present throughout the fault zone. Microthermometric data from primary, mixed CO2-H2O fluid inclusions in boudin-neck quartz-carbonate veins indicate that these inclusions were trapped at temperatures of 325 ± 15 °C and pressures of c. 40 MPa. Vein microstructures indicate that fluid temperatures were equal to rock temperatures. Assuming hydrostatic fluid pressure, the veins were trapped at depths of < 8 km for an average density of mixed H2O-CO2 fluids in the shallower crust of > 500 kg m- 3.Biotite grains in the mylonites are a mixture of porphyroclastic grains with high R = Ti/Mg# inherited from the parent Alpine Schist, and smaller, low R grains that recrystallised during mylonitisation, particularly those that are found within syn-mylonitic shear bands. Assuming a simple step-function model approximating diffusive equilibration, the changes in biotite chemistry indicate ?T during mylonitic deformation of ˜-340 °C according to the Ti-in-biotite thermometer of Henry et al. (2005).A best-fit uplift P-T path to existing data and these new results indicate that the uplift path P-T gradient of fault zone rocks above the brittle-viscous transition is of the order of 40 °C km- 1. Below the brittle-viscous transition, the uplift path P-T gradient is 10 °C km- 1. The P-T profile within the fault rocks is comparable to that in the immediate hanging wall Alpine Schist, indicating there is no peak in the crustal isotherms in the fault hanging wall, as was indicated by previous numerical models, and analyses that did not consider data from the fault rocks themselves.

Toy, Virginia G.; Craw, Dave; Cooper, Alan F.; Norris, Richard J.

2010-04-01

58

Hydrologic connections of a stream aquifer-vegetation zone in south-central Platte River valley, Nebraska  

NASA Astrophysics Data System (ADS)

Field investigation and numerical modeling approaches were used to examine the hydrologic relations between the Platte River and the adjacent alluvial aquifer and riparian zone in south-central Nebraska. Field methods include direct-push techniques for coring and electric logging in the river channel, permeameter tests for estimating the hydraulic conductivity of the streambed, and monitoring of groundwater levels responding to changes in stream stages and to groundwater evapotranspiration. The channel sediments consist mostly of coarse sand and gravels at the study site with large values of horizontal and vertical hydraulic conductivity. Groundwater in the riparian zone responded nearly simultaneously to the changes in stream stages, and diurnal fluctuations of the water table are correlated with fluctuations of stream stage in summer. All these indicate a well-connected river-aquifer-vegetation hydrologic system. Numerical models, based on the Galerkin finite element method, were developed to construct detailed flow nets for examining the changes in the patterns of groundwater flow dynamics resulting from the use of groundwater and stream water by riparian vegetation. Simulation results suggest that a number of hydrologic factors, such as the thickness of the aquifer and vertical anisotropy of aquifer hydraulic conductivity, also affect the flow patterns. Vertical flow is a major component, more significant than the horizontal flow below the river and the vegetation zone in the growing season. Groundwater evapotranspiration can bring deeper groundwater to the water table by hydraulic lift. This function of riparian vegetation could cause a complicated situation in an investigation of groundwater quality in riparian zones.

Chen, Xunhong

2007-02-01

59

The formation and chemistry of low degree hydrous partial melt on top of the transition zone  

Microsoft Academic Search

There is some geophysical evidence for the presence of silicate melt on top of the 410 km seismic discontinuity. It has also been argued that the difference in the water storage capacity of upper mantle versus transition zone minerals may cause dehydration melting as material up-wells across the 410. Studies have proposed that hydrous partial melts may be neutrally buoyant

Daniel J. Frost; Mainak Mookherjee

2010-01-01

60

Redox Chemistry in the Root Zone of a Salt Marsh Sediment in the Tagus Estuary, Portugal  

Microsoft Academic Search

Measurements of O2, Fe(II), Mn(II)and HS5 in salt marshsediments in the Tagus Estuary, Portugal, made with a voltammetric microelectrode, reveal strong seasonal differences in pore water composition within the 20~cm deep root zone. In spring, oxygen was below detection limit except close to the sediment surface. Fe(II) was present below 5 cm in concentrations ranging from detection limit to 1700

Bjørn Sundby; Carlos Vale; Miguel Caetano; George W. Luther III

2003-01-01

61

Pore fluid chemistry of the North Anatolian Fault Zone in the Sea of Marmara: A diversity of sources and processes  

NASA Astrophysics Data System (ADS)

As part of the 2007 Marnaut cruise in the Sea of Marmara, an investigation of the pore fluid chemistry of sites along the Main Marmara Fault zone was conducted. The goal was to define the spatial relationship between active faults and fluid outlets and to determine the sources and evolution of the fluids. Sites included basin bounding transtensional faults and strike-slip faults cutting through the topographic highs. The basin pore fluids are dominated by simple mixing of bottom water with a brackish, low-density Pleistocene Lake Marmara end-member that is advecting buoyantly and/or diffusing from a relatively shallow depth. This mix is overprinted by shallow redox reactions and carbonate precipitation. The ridge sites are more complex with evidence for deep-sourced fluids including thermogenic gas and evidence for both silicate and carbonate diagenetic processes. One site on the Western High displayed two mound structures that appear to be chemoherms atop a deep-seated fluid conduit. The fluids being expelled are brines of up to twice seawater salinity with an exotic fluid chemistry extremely high in Li, Sr, and Ba. Oil globules were observed both at the surface and in cores, and type II gas hydrates of thermogenic origin were recovered. Hydrate formation near the seafloor contributes to increase brine concentration but cannot explain their chemical composition, which appears to be influenced by diagenetic reactions at temperatures of 75°C-150°C. Hence, a potential source for fluids at this site is the water associated with the reservoir from which the gas and oil is seeping, which has been shown to be related to the Thrace Basin hydrocarbon system. Our work shows that submerged continental transform plate boundaries can be hydrologically active and exhibit a diversity of sources and processes.

Tryon, M. D.; Henry, P.; ?A?Atay, M. N.; Zitter, T. A. C.; GéLi, L.; Gasperini, L.; Burnard, P.; Bourlange, S.; Grall, C.

2010-10-01

62

Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone  

USGS Publications Warehouse

Although the presence of extensive gas hydrate on the Cascadia margin, offshore from the western U.S. and Canada, has been inferred from marine seismic records and pore water chemistry, solid gas hydrate has only been found at one location. At Ocean Drilling Program (ODP) Site 892, offshore from central Oregon, gas hydrate was recovered close to the sediment - water interface at 2-19 m below the seafloor, (mbsf) at 670 m water depth. The gas hydrate occurs as elongated platy crystals or crystal aggregates, mostly disseminated irregularly, with higher concentrations occurring in discrete zones, thin layers, and/or veinlets parallel or oblique to the bedding. A 2-to 3-cm thick massive gas hydrate layer, parallel to bedding, was recovered at ???17 mbsf. Gas from a sample of this layer was composed of both CH4 and H2S. This sample is the first mixed-gas hydrate of CH4-H2S documented in ODP; it also contains ethane and minor amounts of CO2. Measured temperature of the recovered core ranged from 2 to - 18??C and are 6 to 8 degrees lower than in-situ temperatures. These temperature anomalies were caused by the partial dissociation of the CH4-H2S hydrate during recovery without a pressure core sampler. During this dissociation, toxic levels of H2S (??34S, +27.4???) were released. The ??13C values of the CH4 in the gas hydrate, -64.5 to -67.5???(PDB), together with ??D values of - 197 to - 199???(SMOW) indicate a primarily microbial source for the CH4. The ??18O value of the hydrate H2O is +2.9???(SMOW), comparable with the experimental fractionation factor for sea-ice. The unusual composition (CH4-H2S) and depth distribution (2-19 mbsf) of this gas hydrate indicate mixing between a methane-rich fluid with a pore fluid enriched in sulfide; at this site the former is advecting along an inclined fault into the active sulfate reduction zone. The facts that the CH4-H2S hydrate is primarily confined to the present day active sulfate reduction zone (2-19 mbsf), and that from here down to the BSR depth (19-68 mbsf) the gas hydrate inferred to exist is a ???99% CH4 hydrate, suggest that the mixing of CH4 and H2S is a geologically young process. Because the existence of a mixed CH4-H2S hydrate is indicative of moderate to intense advection of a methane-rich fluid into a near surface active sulfate reduction zone, technically active (faulted) margins with organic-rich sediments and moderate to high sedimentation rates are the most likely regions of occurrence. The extension of such a mixed hydrate below the sulfate reduction zone should reflect the time-span of methane advection into the sulfate reduction zone. ?? 1998 Elsevier Science B.V. All rights reserved.

Kastner, M.; Kvenvolden, K. A.; Lorenson, T. D.

1998-01-01

63

Using biodiversity of diatoms to identify hydrological connectivity in the hillslope-riparian zone-stream system  

NASA Astrophysics Data System (ADS)

In recent years, there have been increasingly calls for new eco-hydrological approaches to answer questions on water source and connectivity in the landscape. Diatoms are one of the most common and diverse algal groups, and offer the potential for the identification of reproducible flow patterns and a link to underlying watershed behaviour. Our preliminary investigations on the potential for terrestrial diatoms to detect the onset/cessation of surface runoff suggested that diatoms can contribute to confirm or reject the existence of a surface runoff component in total runoff, thereby helping to constrain assumptions made on a potential surface runoff component in a conventional tracer based hydrograph separation. Our investigations currently focus on the Attert River basin (Luxembourg, Europe) and the HJ Andrews experimental forest (Oregon, USA). Here we show results from the schistose Weierbach experimental catchment (0.45 km2), located in the Attert River basin. Ordination analysis revealed a clear distinction between communities belonging to the river bed substrate and the riparian zone. Drift samples corresponding to stream water show a mixed composition of diatoms stemming from the river bed substrate and the riparian zone. Ongoing investigations focus on the composition of hillslope communities. In winter, long-lasting low intensity rainfall events generate a two-tailed hydrograph response of the Weierbach, consisting in an immediate reaction to precipitation, followed by a delayed and much more significant rise of the hydrograph. For these events, mixing diagrams (SiO2 & Absorbance) suggest a substantial contribution of the soil water component to total runoff, with groundwater and especially overland flow remaining insignificant. Terrestrial diatom abundance appeared to be very sensitive to incident precipitation (rising to +/- 15% of the total diatom population), suggesting a rapid connectivity between the soil surface and the stream. In summer, short and very intense rainfall events cause a single-tailed rather small rise of the hydrograph in the Weierbach. Mixing diagrams suggest a very brief and intense switch from groundwater to soil water contribution. Almost simultaneously to incoming precipitation, terrestrial diatom abundance increases to 20-30% inside the stream. Species composition was also seasonally structured. During winter season (November 2010 and January 2011 events) the diatom drift was characterized and dominated by colony forming species (e.g. Fragilaria nevadensis Linares-Cuesta & Sánchez-Castillo and Fragilariforma virescens (Ralfs) Williams & Round), while summer events were characterized by a large number of small aerophytic species (i.e. Chamaepinnularia evanida (Hustedt) Lange-Bertalot, Eolimna tantula (Hustedt) Lange-Bertalot, Navicula obsoleta Hustedt, Navicula parsura Hustedt and Stauroneis thermicola (Petersen) Lund). Chemical tracers suggest a substantial role of soil water contributions to storm hydrographs in the Weierbach, regardless of the season, with overland flow playing no prominent role at all. Meanwhile, terrestrial diatom abundance in drift samples strongly increases during precipitation events, suggesting a rapid onset of connectivity between the soil surface and the stream. We assume the terrestrial diatoms to be mobilized during precipitation and eventually flushed to the stream through a subsurface network of macropores in the shallow soils and cracks in the fractured and weathered schistose bedrock.

Wetzel, C. E.; Martínez-Carreras, N.; Ector, L.; Hlubikova, D.; Frentress, J.; McDonnell, J. J.; Hoffmann, L.; Pfister, L.

2012-04-01

64

Making every SAR point count: the development of Chemistry Connect for the large-scale integration of structure and bioactivity data  

Microsoft Academic Search

\\u000a The increase in drug research output from patent applications, together with the expansion of public data collections, such as ChEMBL and PubChem BioAssay, has made it essential for pharmaceutical companies to integrate both internal and external 'SAR estate'. The AstraZeneca response has been the development of an enterprise application, Chemistry Connect, containing 45 million unique chemical structures from 18 internal

Sorel Muresan; Plamen Petrov; Christopher Southan; Magnus J. Kjellberg; Thierry Kogej; Christian Tyrchan; Peter Varkonyi; Paul Hongxing H. Xie

2011-01-01

65

Cobinamide chemistries for photometric cyanide determination. A merging zone liquid core waveguide cyanide analyzer using cyanoaquacobinamide  

PubMed Central

Diaquacobinamide (H2O)2Cbi2+ or its conjugate base hydroxyaquacobinamide (OH(H2O)Cbi+)) can bind up to two cyanide ions, making dicyanocobinamide. This transition is accompanied by a significant change in color, previously exploited for cyanide determination. The reagent OH(H2O)Cbi+ is used in excess; when trace amounts of cyanide are added, CN(H2O)Cbi+ should be formed. But the spectral absorption of CN(H2O)Cbi+ is virtually the same as that of OH(H2O)Cbi+. It has been inexplicable how trace amounts of cyanide are sensitively measured by this reaction. It is shown here that even with excess OH(H2O)Cbi+, (CN)2Cbi is formed first due to kinetic reasons; this only slowly forms CN(H2O)Cbi+. This understanding implies that CN(H2O)Cbi+ will itself be a better reagent. We describe a single valve merging zone flow analyzer that allows both sample and reagent economy. With a 50 cm liquid core waveguide (LCW) flow cell and an inexpensive fiber optic - charge coupled device array spectrometer, a S/N=3 limit of detection of 8 nM, a linear dynamic range to 6 ?M, and excellent precision (RSD 0.49% and 1.07% at 50 and 100 nM, respectively, n=5 each) are formed. At 1% carryover, sample throughput is 40 h?1. The setup is readily used to measure thiocyanate with different reagents. We demonstrate applicability to real samples by analyzing human saliva samples and hydrolyzed extracts of apple seeds, peach pits, and almonds.

Ma, Jian; Dasgupta, Purnendu K.; Zelder, Felix H.; Boss, Gerry R.

2012-01-01

66

Connecting knowledge of physics and chemistry in teaching: behaviour of a jet of water in the presence of charged insulators  

Microsoft Academic Search

The main aim of this study is to find out how physics and chemistry teacher trainees apply and integrate their knowledge in physics and chemistry ac- quired during their studies in the corresponding subject departments in a teaching situation. In the first part of the study the senior secondary school students' (age 16- 17) interpretations about the experiment in which

Liisa Kyyrönen

67

Particulate matter chemistry and dynamics in the Twilight Zone at VERTIGO ALOHA and K2 Sites  

SciTech Connect

Understanding particle dynamics in the 'Twilight Zone' is critical to prediction of the ocean's carbon cycle. As part of the VERTIGO (VERtical Transformations In the Global Ocean) project, this rarely sampled regime extending from the base of the euphotic layer to 1000 m, was characterized by double-paired day/night Multiple Unit Large Volume in-situ Filtration System (MULVFS) deployments and by {approx}100 high-frequency CTD/transmissometer/turbidity sensor profiles. VERTIGO studies lasting three weeks, contrasted oligotrophic station ALOHA (22.75{sup o}N 158{sup o}W), sampled in June-July 2004, with a biologically productive location (47{sup o}N 161{sup o}E) near station K2 in the Oyashio, occupied July-August 2005. Profiles of major and minor particulate components (C{sub org}, N, P, Ca, Si, Sr, Ba, Mn) in <1, 1-51, and >51 {micro}m size fractions, in-water optics, neutrally buoyant sediment trap (NBST) fluxes, and zooplankton data were intercompared. MULVFS total C{sub org} and C-Star particle beam attenuation coefficient (C{sub P}) were consistently related at both sites with a 27 {micro}M m{sup -1} conversion factor. 26 At K2, C{sub P} profiles further showed a multitude of transient spikes throughout the water column and spike abundance profiles closely paralleled the double peaked abundance profiles of zooplankton. Also at K2, copepods contributed {approx}40% and 10%, night and day, respectively to >51 {micro}m C{sub org} of MULVFS samples in the mixed layer, but few copepods were collected in deeper waters; however, non-swimming radiolarians were quantitatively sampled. A recent hypothesis regarding POC differences between pumps and bottles is examined in light of these results. Particulate >51 {micro}m C{sub org}, N, and P at both ALOHA and K2 showed strong attenuation with depth at both sites. Notable at ALOHA were unusually high levels of >51 {micro}m Sr (up to 4 nM) in the mixed layer, a reflection of high abundances of SrSO{sub 4} precipitating Acantharia. Notable at K2 were major changes in water column inventories of many particulate components to 700 m over 10 days. Carbon mass balance, with the consideration of particle inventory changes included, indicated that over 98% and 96% of primary produced C{sub org} was remineralized shallower than 500 m at ALOHA and K2, respectively. Production of CaCO3 was estimated to be {approx}0.06, 0.89 and 0.02 mmols m{sup -2} d{sup -1} at ALOHA and at K2 during two separate week long study periods, respectively. Similarly, Si production was estimated to be {approx}0.08, 10.7, and 4.2 mols m{sup -2} d{sup -1}. An estimated 50% and 65% of produced Si was remineralized by 500m at ALOHA and K2, respectively. Little carbonate dissolution was seen in the upper 500 m at ALOHA, a reflection of 400% super saturation of surface waters and the 700 m deep saturation horizon. Over 92% of produced CaCO{sub 3} was dissolved shallower than 500 m at K2 and biological enhancement of dissolution was readily apparent in waters above the 200 m calcite saturation horizon.

Bishop, James K.B.; Wood, T.J.

2008-03-25

68

A multi-zone chemistry mapping approach for direct numerical simulation of auto-ignition and flame propagation in a constant volume enclosure  

Microsoft Academic Search

A direct numerical simulation (DNS) coupling with multi-zone chemistry mapping (MZCM) is presented to simulate flame propagation and auto-ignition in premixed fuel\\/air mixtures. In the MZCM approach, the physical domain is mapped into a low-dimensional phase domain with a few thermodynamic variables as the independent variables. The approach is based on the fractional step method, in which the flow and

M. Jangi; R. Yu; X. S. Bai

2011-01-01

69

A multi-zone chemistry mapping approach for direct numerical simulation of auto-ignition and flame propagation in a constant volume enclosure  

Microsoft Academic Search

A direct numerical simulation (DNS) coupling with multi-zone chemistry mapping (MZCM) is presented to simulate flame propagation and auto-ignition in premixed fuel\\/air mixtures. In the MZCM approach, the physical domain is mapped into a low-dimensional phase domain with a few thermodynamic variables as the independent variables. The approach is based on the fractional step method, in which the flow and

M. Jangi; R. Yu; X. S. Bai

2012-01-01

70

Structural organization of process zones in upland watersheds of central Nevada and its influence on basin connectivity, dynamics, and wet meadow complexes  

NASA Astrophysics Data System (ADS)

The drainage network within upland watersheds in central Nevada can be subdivided into distinct zones each dominated by a unique set of processes on the basis of valley form, the geological materials that comprise the valley floor, and the presence or absence of surficial channels. On hillslopes, the type and structure (frequency, length, and spatial arrangement) of these process zones is related to the lithology and weathering characteristics of the underlying bedrock. Process zones dominated by sediment accumulation, storage, and groundwater recharge are associated with less resistant rocks that weather into abundant but relatively small particles. Sediment transport and runoff-dominated zones are associated with resistant, sparsely fractured rocks that produce limited but larger clasts. The type and structure of process zones along axial valleys depend on the characteristics of the process zones on the hillslopes. Numerous sediment storage-dominated reaches leads to a relatively high number of unincised fans located at the mouth of tributaries along the axial valleys and to frequent and lengthy unincised valley segments, both of which disconnect large sections of the drainage basin from channelized flows. In contrast, a relatively high density of transport-dominated process zones leads downstream to the incision of side-valley fans and axial valley deposits as well as a high degree of basin connectivity (defined by the integration of surficial channels). Connectivity also is related to the lithology of the underlying bedrock, with higher degrees of connectivity being associated with volcanic rocks that presumably yield high rates of runoff. Lower levels of connectivity are associated most frequently with extensively fractured, locally permeable sedimentary and metamorphic rock assemblages. Thus, basins underlain by volcanic rocks appear to be more sensitive to incision and produce more dynamic channels in terms of the rate of channel/valley modification than those underlain by other lithologies. Considerable attention has been devoted in recent years to the management of wet meadow ecosystems that serve as important riparian habitats within upland basins of central Nevada. The data presented here show that, within basins characterized by a high degree of connectivity, areas of wet meadow are minimal. Where they do exist in these basins, they tend to be severely degraded by incision or gully erosion and will be difficult to manage given the dynamic nature of the axial channel processes. Wet meadows within basins that exhibit a low degree of connectivity and high sediment storage-to-transport ratios on hillslopes will likely be more responsive to management activities because of the reduced threats of channel incision and, presumably, a larger supply of groundwater flow to the meadows created by an extensive network of recharge sites. Importantly, human activities that lead to an increase in basin connectivity can negatively impact downstream meadows through a decrease in groundwater recharge and an increase in stream dynamics, in spite of the fact that these activities may be physically separated from the wet meadow areas.

Miller, Jerry R.; Lord, Mark L.; Villarroel, Lionel F.; Germanoski, Dru; Chambers, Jeanne C.

2012-02-01

71

General Chemistry: Expanding the Learning Outcomes and Promoting Interdisciplinary Connections through the Use of a Semester-Long Project  

ERIC Educational Resources Information Center

|The laboratory component of a first-semester general chemistry course for science majors is described. The laboratory involves a semester-long project undertaken in a small-group format. Students are asked to examine whether plants grown in soil contaminated with lead take up more lead than those grown in uncontaminated soil. They are also asked…

Wenzel, Thomas J.

2006-01-01

72

Fluid chemistry and evolution of hydrothermal fluids in an Archaean transcrustal fault zone network: The case of the Cadillac Tectonic Zone, Abitibi greenstone belt, Canada  

USGS Publications Warehouse

Detailed fluid geochemistry studies on hydrothermal quartz veins from the Rouyn-Noranda and Val-d'Or areas along the transcrustal Cadillac Tectonic Zone (CTZ) indicate that unmineralized (with respect to gold) sections of the CTZ contained a distinct CO2-dominated, H2S-poor hydrothermal fluid. In contrast, both gold mineralized sections of the CTZ (e.g., at Orenada #2) and associated higher order shear zones have a H2O-CO2 ?? CH4-NaCl hydrothermal fluid. Their CO2/H2S ratios indicate H2S-rich compositions. The Br/Cl compositions in fluid inclusions trapped in these veins indicate that hydrothermal fluids have been equilibrated with the crust. Oxygen isotope ratios from hydrothermal quartz veins in the CTZ are consistently 2??? more enriched than those of associated higher order shear zones, which are interpreted to be a function of greater fluid/rock ratios in the CTZ and lower fluid/rock ratios, and more efficient equilibration of the hydrothermal fluid with the wall rock, in higher order shear zones. An implication from this study is that the lower metal endowment of the transcrustal CTZ, when compared with the higher metal endowment in higher order shear zones (ratio of about 1 : 1000), may be the result of the lack of significant amounts of H2O-H2S rich fluids in most of the CTZ. In contrast, gold mineralization in the higher order shear zones appear to be controlled by the high H2S activity of the aqueous fluids, because gold was likely transported in a bisulfide complex and was deposited during sulfidation reactions in the wall rock and phase separation in the quartz veins. ?? 2007 NRC Canada.

Neumayr, P.; Hagemann, S. G.; Banks, D. A.; Yardley, B. W. D.; Couture, J. -F.; Landis, G. P.; Rye, R.

2007-01-01

73

Nutrient transfer between the root zones of soybean and maize plants connected by a common mycorrhizal mycelium  

Microsoft Academic Search

The objective of the study was to determine whether nutrient fluxes mediated by hyphae of vesicular-arbuscular myeorrhizal (VAM) fungi between the root zones of grass and legume plants differ with the legume's mode of N nutrition. The plants, nodulating or nonnodulating isolines of soybean (Glycine max (L.) Merr.J, were grown in association with a dwarf maize (Zea mays L.) eultivar

Gabor J. Bethlenfalvay; Maria G. Reyes-Solis; Susan B. Camel; Ronald Ferrera-Cerrato

1991-01-01

74

Chemistry, isotopic composition, and origin of a methane-hydrogen sulfide hydrate at the Cascadia subduction zone  

Microsoft Academic Search

Although the presence of extensive gas hydrate on the Cascadia margin, offshore from the western U.S. and Canada, has been inferred from marine seismic records and pore water chemistry, solid gas hydrate has only been found at one location. At Ocean Drilling Program (ODP) Site 892, offshore from central Oregon, gas hydrate was recovered close to the sediment-water interface at

Miriam Kastner; Keith A. Kvenvolden; Thomas D. Lorenson

1998-01-01

75

An autoradiographic analysis of the cortical connections of the pallidal and cerebellar zones within the feline motor thalamus  

SciTech Connect

The feline motor thalamus relays both basal ganglia and cerebellar inputs to the motor cortex. This complex is classically subdivided into three nuclei: the ventroanterior nucleus (VA), the ventrolateral nucleus (VL), and the ventromedial nucleus (VM). Poor correlation between recognized patterns of cortical and subcortical connectivity and traditional boundaries used to distinguish these nuclei complicate the elucidation of the role they play in the elaboration of motor behavior. The recent demonstration of complementarity for the pallidothalamic and dentatothalamic projections to the motor thalamus of the cat provided the foundation for a revision of these nuclear borders to reflect differences in subcortical connectivity. Using a revised topography, this study analyzed the afferent and efferent connections of the feline VA and VL through the application of both anterograde and retrograde tracing techniques. The extent of the cerebellothalamic projection, as revealed by the bidirectional transport of WGA-HRP, was used to demarcate the boundary between VA and VL. Injections of tritiated amino acids into VA and VL allowed for the autoradiographic tracing of their cortical projections. Autoradiography was also used to demonstrate the distributions of corticothalamic projections from selected pericruciate and posterior parietal subfields to the motor thalamus.

Wensel, J.P.

1989-01-01

76

Limits to magma mixing based on chemistry and mineralogy of pumice fragments erupted from a chemically zoned magma body  

Microsoft Academic Search

The chemical variation among pumice fragments from the Pahute Mesa Member of the Thirsty Canyon Tuff (Black Mountain volcanic center, southwestern Nevada) is consistent with magma withdrawal from a chemically zoned magma body. The top of this magma body contained little chemical variations, the lowest concentration of light REEs, and the highest concentrations of SiOâ, heavy REEs, and Th. The

Thomas A. Vogel; Frederick J. Ryerson; Donald C. Noble; Leland W. Younker

1987-01-01

77

Sporadic metal atom and ion layers and their connection to chemistry and thermal structure in the mesopause region at Arecibo  

NASA Astrophysics Data System (ADS)

We present an analysis of two separate and distinct sporadic layer events in the mesosphere and lower thermosphere region above the Arecibo Observatory. These layers were observed in both neutral K and ionic Ca+ with lidars, and in electron density with incoherent scatter radar. Temperature profiles were determined from the K lidar. One sporadic event was a high altitude layer, in which both atomic and ion sporadic layers were positioned above 100 km altitude. This represents a relatively common sporadic layer visible in both ions and neutrals at Arecibo. The other observation was less typical, with a lower altitude and more diffuse sporadic E layer, extending from below 90 km to above 95 km, which dissipated coincident with growth of a sporadic neutral K layer. We analyze these separate events using a temperature-dependent chemical model, which employs commonly accepted chemical processes. We find that the model successfully reproduces the high altitude layer of June 12-13, 2002. The result shows a temperature dependence related to the chemical lifetimes of the metallic constituents, and that the neutral layer would not have formed had the temperature profile matched that of the MSIS-90 model. Second, the temperature dependent chemistry model also reproduced K+ in close agreement with electron densities on June 14-15, 2002. However, the modeled neutrals do not agree well with the observation above 90 km, and it likely requires inclusion of dynamical forcing and advection. We speculate that model and observational deficiencies, primarily exclusion of dynamics such as advection and wave interactions, are the likely shortcomings in the failure to reproduce the observations.

Delgado, Rubén; Friedman, Jonathan S.; Fentzke, Jonathan T.; Raizada, Shikha; Tepley, Craig A.; Zhou, Qihou

2012-01-01

78

DNAPL Surface Chemistry: Its Impact on DNAPL Distribution in the Vadose Zone and its Manipulation to Enhance Remediation  

SciTech Connect

The remediation of DNAPLs in subsurface environments is often limited by the heterogeneous distribution of the organic fluid. The fraction of DNAPL that is in the high conductivity regions of the subsurface can often be recovered relatively easily, although DNAPL in lower conductivity regions is much more difficult to extract, either through direct pumping or remediation measures based on interface mass transfer. The distribution of DNAPL within the vadose zone is affected by a complex interplay of heterogeneities in the porous matrix and the interfacial properties defining the interactions among all fluid and solid phases. Decreasing the interfacial tension between a DNAPL and water in the vadose zone could change the spreading of the DNAPL, thereby increase the surface area for mass transfer and the effectiveness of soil vapor extraction remediation.

Suan Power; Stefan Grimberg; Miles Denham

2003-06-16

79

Mineral chemistry of submarine lavas from Hilo Ridge, Hawaii: implications for magmatic processes within Hawaiian rift zones  

Microsoft Academic Search

The crustal history of volcanic rocks can be inferred from the mineralogy and compositions of their phenocrysts which record\\u000a episodes of magma mixing as well as the pressures and temperatures when magmas cooled. Submarine lavas erupted on the Hilo\\u000a Ridge, a rift zone directly east of Mauna Kea volcano, contain olivine, plagioclase, augite ±orthopyroxene phenocrysts. The\\u000a compositions of these phenocryst

Huai-Jen Yang; Frederick A. Frey; David A. Clague; Michael O. Garcia

1999-01-01

80

Cycling of Li, K, Rb, and Cs at Subduction Zones and Ridge Crests With Implications for Ocean Chemistry: Hydrothermal Experiments at 35-350° C and 600 bars  

NASA Astrophysics Data System (ADS)

The alkali metals (Li, K, Rb, Cs) are excellent tracers of fluid-rock reactions and cycling because of strong partitioning into the fluid phase, particularly at moderate to high temperatures. As such, they can provide critical information on the process of fluid recycling at the principal plate boundary, the reaction site temperature, the nature of the reacting solid phases (i.e. the involvement of sediment in arc volcanoes), with links to seawater (SW) chemistry. Our hydrothermal experiments indicate that the reactivity of each alkali metal is distinct; each has a characteristic behavior with respect to partitioning into the fluid phase with temperature. The data thus suggest that alkali concentration ratios together with Li isotopes may be used for geothermometry. MORB-SW and smectite-SW hydrothermal experiments were conducted between 35-350° C at 25° C, 600 bars, and a water/rock mass ratio of ˜5, using the Dickson-type rocking autoclave. Run-times continued until steady-state partitioning was observed. In the MORB-SW experiments, fluid K/Cl molar ratios first increase slightly, from 35-65° C, then decrease to a minimum of 1.1 x10-2 at 275° C. At >275° C the ratio sharply increases to 6.0 x10-2 at 350° C. In contrast, Li/Cl, Rb/Cl, and Cs/Cl ratios all increase from 35-350° C, but each at a distinct slope, indicating significant fractionation between the alkali metals. The Li/Cl ratio gently increases between 35-250° C, and sharply increases to a ratio of ˜1.20 x10-3 at 350° C. Rb/Cl behaves similarly, except for a higher inflection temperature of ˜300° C, and a steeper slope between 300-350° C. Cs/Cl behaves distinctly, the ratio increasing steadily with temperature (i.e. no inflection point) to 1.8 x10-8 at 350° C. Consequently, Li/K and Cs/K ratios exhibit sharp maxima at ˜275° C, at 35 x10-3 & 10 x10-6, respectively. In the smectite-SW experiments there is no reversal in slope, thus the sediment influence on the fluid chemistry can be clearly identified. Rb/K, in contrast to Li/K and Cs/K, do not have a maximum, but steadily increase from 35-350° C in the MORB experiments. In the smectite experiments, the fluid Rb/K ratios are considerably higher, hence, are as well indicators of sediment contribution. At 350° C the enrichment factors (ER) of Li/Cl and Cs/Cl are higher in the smectite than in the MORB experiments ( ˜70 & 150 vs. ˜20 & 30, respectively). The ER of Rb/Cl is ˜10 in both experiments, but that of K/Cl is higher in the MORB vs. smectite experiments (3.0 & 1.7, respectively). Like Sr, the fluid Li totally exchanges its isotopes with MORB or with the smectite. In the MORB experiments, the fluid ? 7Li fall on a SW-MORB mixing line, shifting from 30.95‰ , the SW value, to17.4‰ at 150° C, and 7.33‰ at 350° C. Hence, ? 7Li values together with Li/K, Li/Rb and Li/Cs ratios constrain the reaction temperature (±20-30° C) and the nature of the rock involved. Applications of the experimental data (1) to pore fluids from two subduction zones: the Middle America Trench offshore Costa Rica, and the Nankai Trough, and to an 'average' ridge crest hydrothermal fluid composition, and (2) to revised Rb and Cs ocean budgets, will be presented.

Wei, W.; Kastner, M.; Rosenbauer, R.; Weinstein, Y.; Chan, L.

2004-12-01

81

Hydrogeology, water chemistry, and transport processes in the zone of contribution of a public-supply well in Albuquerque, New Mexico, 2007-9  

USGS Publications Warehouse

The National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey began a series of groundwater studies in 2001 in representative aquifers across the Nation in order to increase understanding of the factors that affect transport of anthropogenic and natural contaminants (TANC) to public-supply wells. One of 10 regional-scale TANC studies was conducted in the Middle Rio Grande Basin (MRGB) in New Mexico, where a more detailed local-scale study subsequently investigated the hydrogeology, water chemistry, and factors affecting the transport of contaminants in the zone of contribution of one 363-meter (m) deep public-supply well in Albuquerque. During 2007 through 2009, samples were collected for the local-scale study from 22 monitoring wells and 3 public-supply (supply) wells for analysis of major and trace elements, arsenic speciation, nutrients, dissolved organic carbon, volatile organic compounds (VOCs), dissolved gases, stable isotopes, and tracers of young and old water. To study groundwater chemistry and ages at various depths within the aquifer, the monitoring wells were divided into three categories: (1) each shallow well was screened across the water table or had a screen midpoint within 18.3 m of the water level in the well; (2) each intermediate well had a screen midpoint between about 27.1 and 79.6 m below the water level in the well; and (3) each deep well had a screen midpoint about 185 m or more below the water level in the well. The 24-square-kilometer study area surrounding the "studied supply well" (SSW), one of the three supply wells, consists of primarily urban land within the MRGB, a deep alluvial basin with an aquifer composed of unconsolidated to moderately consolidated deposits of sand, gravel, silt, and clay. Conditions generally are unconfined, but are semiconfined at depth. Groundwater withdrawals for public supply have substantially changed the primary direction of flow from northeast to southwest under predevelopment conditions, to west to east under modern conditions. Analysis of age tracers indicates that groundwater from most sampled wells is dominated by old (pre-1950) water, ranging in mean age from about 4,000 years to more than 22,000 years, but includes a fraction of young (post-1950) recharge. Patterns in chemical and isotopic data are consistent with the conclusions that shallow groundwater in the area typically includes a fraction that evaporated prior to recharge and (or) flushed accumulated solutes out of the unsaturated zone during recharge, and that shallow groundwater has mixed to deeper parts of the aquifer, which receives recharge mainly by seepage from the Rio Grande. Among shallow and intermediate wells that produced water with a fraction of young recharge, that fraction ranged between 1.5 and 46 percent. Samples from the two deep wells had groundwater ages exceeding 18,000 years, with no fraction of young recharge. Two supply wells (including the SSW) had a fraction of young recharge, which ranged between about 3 and 11 percent, despite mean groundwater ages exceeding 10,000 years. The fraction of young recharge to the SSW varied seasonally, probably because seasonal pumping patterns affected local hydraulic gradients and (or) because of flow through the well bore when the SSW is not pumping. Well-bore flow data collected during winter (low-pumping season) indicated that about 61 percent of the water pumped from the SSW entered the well from the intermediate part of the aquifer, and that the remaining 39 percent entered from the deep part of the aquifer. Volatile organic compounds (VOCs) were detected in samples from most shallow and intermediate monitoring wells and from two of three supply wells, including the SSW. Detected VOCs were primarily chlorinated solvents or their degradation products. Many of the wells in which most of these VOCs were detected are located near known sites of solvent contamination that were targeted for sampling because trichloroethylene (TCE) and cis-1,2-dichloroethylene had been detected in the SSW, and several of these wells m

Bexfield, Laura M.; Jurgens, Bryant C.; Crilley, Dianna M.; Christenson, Scott C.

2012-01-01

82

Chemistry: Principles and Practice, 3rd ed  

Microsoft Academic Search

A text that truly embodies its name, CHEMISTRY: PRINCIPLES AND PRACTICE connects the chemistry students learn in the classroom (principles) with real-world uses of chemistry (practice). The authors accomplish this by starting each chapter with an application drawn from a chemical field of interest and revisiting that application throughout the chapter. The Case Studies, Practice of Chemistry essays, and Ethics

Daniel L. Reger; Scott L. Goode; David W. Ball

2010-01-01

83

Coupled physical, chemical, and microbiological measurements suggest a connection between internal waves and surf zone water quality in the Southern California Bight  

NASA Astrophysics Data System (ADS)

Internal waves have been implicated in the cross-shore transport of scalars such as larvae, nutrients, and pollutants at locations around the world. The present study combines physical measurements with a comprehensive set of surf zone water quality measurements to evaluate the possible impact of cross-shore internal wave transport on surf zone water quality during two study periods. An array of oceanographic moorings was deployed in the summer of 2005 and 2006 at 10-20 m depth offshore of the beach to observe internal waves. Concurrently, surf zone water quality was assessed twice daily at night at an adjacent station (Huntington State Beach) by measuring concentration of phosphate, dissolved inorganic nitrogen (DIN), silicate, chlorophyll a, fecal indicator bacteria (FIB), and the human-specific fecal DNA marker in Bacteroidales. The baroclinic component accounted for about 30% of the total variance in water column velocity, indicating the importance of density-driven flow during the summer when the water column was stratified. Arrival of cold subthermocline water in the very nearshore (within 1 km of the surf zone) was characterized by strong baroclinic onshore flow near the bottom of the water column. The near bottom, baroclinic, cross-shore current was significantly lag-correlated with the near bottom temperature data along a cross-shore transect towards shore, demonstrating shoreward transport of cold subthermocline water. Wavelet analysis of temperature data showed that non-stationary temperature fluctuations were correlated with buoyancy frequency and the near bottom cross-shore baroclinic current. During periods of large temperature fluctuations, the majority of the variance was within the semi-diurnal band; however, the diurnal and high frequency bands also contained a substantial fraction of total variance. The bottom cross-shore baroclinic current was proposed as a proxy for shoreward transport potential by internal waves and was positively correlated with phosphate concentration in both years, silicate in 2005, and fecal indicator bacteria measurements in 2006. The results suggest internal waves are an important transport mechanism of nutrient-rich subthermocline water to the very nearshore in the Southern California Bight, and may facilitate the transport of FIB into the surf zone or enhance persistence of land-derived FIB.

Wong, Simon H. C.; Santoro, Alyson E.; Nidzieko, Nicholas J.; Hench, James L.; Boehm, Alexandria B.

2012-02-01

84

Water-planets in the Habitable Zone: Atmospheric Chemistry, Observable Features, and the Case of Kepler-62e and -62f  

NASA Astrophysics Data System (ADS)

Planets composed of large quantities of water that reside in the habitable zone are expected to have distinct geophysics and geochemistry of their surfaces and atmospheres. We explore these properties motivated by two key questions: whether such planets could provide habitable conditions and whether they exhibit discernable spectral features that distinguish a water-planet from a rocky Earth-like planet. We show that the recently discovered planets Kepler-62e and -62f are the first viable candidates for habitable zone water-planets. We use these planets as test cases for discussing those differences in detail. We generate atmospheric spectral models and find that potentially habitable water-planets show a distinctive spectral fingerprint in transit depending on their position in the habitable zone.

Kaltenegger, L.; Sasselov, D.; Rugheimer, S.

2013-10-01

85

Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.  

PubMed

Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter. PMID:22169958

Lehn, Jean-Marie

2012-01-01

86

Moving Chemistry Education into 3D: A Tetrahedral Metaphor for Understanding Chemistry  

ERIC Educational Resources Information Center

|A new conceptual metaphor is proposed to enrich the description of chemistry education and support the many existing efforts to help students make connections with the chemistry found in textbooks. A widely used metaphor for chemistry education takes the shape of a planar triangle that highlights three thinking levels in learning chemistry such…

Mahaffy, Peter

2006-01-01

87

Science Connects  

NSDL National Science Digital Library

Science Connects has been chosen to run the STEMNET program for the West of Scotland, and their work will be of great interest to science educators. The STEM ambassador program is what distinguishes the STEMNET program from other STEM programs. The UK-wide program works with "volunteers from a wide range of disciplines, such as forensic science, geology, mechanical engineering, parasitology...etc. who want to share their enthusiasm for their careers to encourage pupils to take an interest in STEM Subjects." The "Case Studies" tab on the left side of any page offers visitors a look at what some ambassadors have done with their field of study. Visitors should check out case study #4, about one Dr. Linda Thomson, who teaches young kids about chemistry and forensics. Visitors will also want to check out case study #9, about Alistair McNeil, who happens to be a health, safety and environment manager who recommends a career in construction. All told, the site is well worth a visit for those interested in promoting STEM education.

88

Chemistry of unsaturated zone gases sampled in open boreholes at the crest of Yucca Mountain, Nevada: Data and basic concepts of chemical and physical processes in the mountain  

Microsoft Academic Search

Boreholes open to the unsaturated zone at the crest of Yucca Mountain, Nevada, were variously sampled for CO2 (including 13C and 14C), CH4, N2, O2, Ar, CFC-11, CFC-12, and CFC-113 from 1986 to 1993. Air enters the mountain in outcrops, principally on the eastern slope, is enriched in CO2 by mixing with soil gas, and is advected to the mountain

Donald C. Thorstenson; Herbert Haas; Eurybiades Busenberg; L. Niel Plummer; Charles A. Peters

1998-01-01

89

Landscape controls on pore water chemistry and chemical weathering rates in the Critical Zone Observatory: Shale Hills Catchment (Central Pennsylvania, USA)  

Microsoft Academic Search

We investigate controls, mechanisms and rates of shale weathering and soil formation at the Susquehanna\\/Shale Hills Critical Zone Observatory of central Pennsylvania. The Shale Hills is forested and V-shaped catchment, with slopes around 16-18%. The parent shales, of Silurian Rose Hill Formation, are comprised of primarily illite, quartz, and chlorite. The dominant chemical reactions in the soil profiles are dissolution

L. Jin; S. L. Brantley

2009-01-01

90

Effects of sequence, connectivity, and counter ions in new amide-linked Ru(tpy)2-Re(bpy) chromophores on redox chemistry and photophysics.  

PubMed

New cationic metallo ligands L1-L3 based on bis(terpyridine) ruthenium(II) complexes decorated with differently substituted 2,2'-bipyridines attached via amide groups (5-NHCO-bpy, 4-CONH-bpy, 5-CONH-bpy) were prepared. Coordination of Re(I)Cl(CO)(3) fragments to the bpy unit gives the corresponding bimetallic Ru~Re complexes 1-3. Hydrogen bonds of the bridging amide groups to [PF(6)](-) counterions or to water molecules are observed both in the solid state and in solution. The impact of the amide orientation, the connecting site, and the coordination of counterions on redox and photophysical properties is explored. Both the metallo ligands L1-L3 and the bimetallic complexes 1-3 are emissive at room temperature in fluid solution. The emission originates from (3)MLCT(Ru) states in all cases. Accordingly, the first oxidation of L1-L3 and 1-3 to [L1](+)-[L3](+) and [1](+)-[3](+) is assigned to the Ru(II/III) couple, while the first reduction to [L1](-)-[L3](-) and [1](-)-[3](-) occurs at the tpy-CO ligand as shown by UV/vis, IR, and EPR spectroscopy of the chemically generated radicals. Under rapid freezing conditions, radicals [2](-) and [3](-) are stabilized as different valence isomers with the odd electron localized at the [bpy-CO](•) bridging unit instead of the [tpy-CO](•). Furthermore, in radical [3](-) this valence equilibrium is shifted from [bpy-CO](•) to [tpy-CO](•) by coordination of [PF(6)](-) counterions to the bridging amide unit and back by replacing the [PF(6)](-) counterion with [BPh(4)](-). Photoinduced electron transfer (?(exc) = 500 nm) to L1-L3 and to 1-3 is successful using triethanolamine (TEOA) as a reducing agent. Photocatalytic reduction of CO(2) by TEOA and 1-3 is hampered by the wrong site of electron localization in the one-electron reduced species [1](-)-[3](-). PMID:23311446

Dietrich, Jan; Thorenz, Ute; Förster, Christoph; Heinze, Katja

2013-01-11

91

Trench Connection  

PubMed Central

‘Trench Connection’ was the first international symposium focusing primarily on the hadal zone (depths greater than 6000 m). It was held at the University of Tokyo's Atmosphere and Ocean Research Institute in November 2010. The symposium was successful in having attracted an international collective of scientists and engineers to discuss the latest developments in the exploration and understanding of the deepest environments on Earth. The symposium sessions were categorized into three themes: (i) new deep-submergence technology; (ii) trench ecology and evolution; and (iii) the physical environment. Recent technological developments have overcome the challenges of accessing the extreme depths, which have in turn prompted an international renewed interest in researching physical and biological aspects of the hadal ecosystems. This bringing together of international participants from different disciplines led to healthy discussions throughout the symposium, providing potential opportunities and realizations of where the future of unravelling hadal ecology lies. Hadal science is still at relatively rudimentary levels compared with those of shallower marine environments; however, it became apparent at the symposium that it is now an ever-expanding scientific field.

Jamieson, Alan J.; Fujii, Toyonobu

2011-01-01

92

Groundwater Hydrology and Chemistry in and near an Emulsified Vegetable-Oil Injection Zone, Solid Waste Management Unit 17, Naval Weapons Station Charleston, North Charleston, South Carolina, 2004-2009  

USGS Publications Warehouse

The U.S. Geological Survey and the Naval Facilities Engineering Command Southeast investigated the hydrology and groundwater chemistry in the vicinity of an emulsified vegetable-oil injection zone at Solid Waste Management Unit (SWMU) 17, Naval Weapons Station Charleston, North Charleston, South Carolina. In May 2004, Solutions-IES initiated a Phase-I pilot-scale treatability study at SWMU17 involving the injection of an edible oil emulsion into the aquifer near wells 17PS-01, 17PS-02, and 17PS-03 to treat chlorinated solvents. The Phase-I injection of emulsified vegetable oil resulted in dechlorination of trichloroethene (TCE) to cis-1,2-dichloroethene (cDCE), but the dechlorination activity appeared to stall at cDCE, with little further dechlorination of cDCE to vinyl chloride (VC) or to ethene. The purpose of the present investigation was to examine the groundwater hydrology and chemistry in and near the injection zone to gain a better understanding of the apparent remediation stall. It is unlikely that the remediation stall was due to the lack of an appropriate microbial community because groundwater samples showed the presence of Dehalococcoides species (sp.) and suitable enyzmes. The probable causes of the stall were heterogeneous distribution of the injectate and development of low-pH conditions in the injection area. Because groundwater pH values in the injection area were below the range considered optimum for dechlorination activity, a series of tests was done to examine the effect on dechlorination of increasing the pH within well 17PS-02. During and following the in-well pH-adjustment tests, VC concentrations gradually increased in some wells in the injection zone that were not part of the in-well pH-adjustment tests. These data possibly reflect a gradual microbial acclimation to the low-pH conditions produced by the injection. In contrast, a distinct increase in VC concentration was observed in well 17PS-02 following the in-well pH increase. Adjustment of the pH to near-neutral values in well 17PS-02 may have made that well relatively favorable to VC production compared with much of the rest of the injection zone, possibly accounting for acceleration of VC production at that well. Following a Phase-II injection in which Solutions-IES, Inc., injected pH-buffered emulsified vegetable oil with an improved efficiency injection approach, 1,1-dichloroethene, TCE, and cDCE rapidly decreased in concentration and are now (2009) undetectable in the injection zone, with the exception of a low concentration (43 micrograms per liter, August 2009) of cDCE in well 17PS-01. In August 2009, VC was still present in groundwater at the test wells in concentrations ranging from 150 to 640 micrograms per liter. The Phase-II injection, however, appears to have locally decreased aquifer permeability, possibly resulting in movement of contamination around, rather than through, the treatment area.

Vroblesky, Don A.; Petkewich, Matthew D.; Lowery, Mark A.; Conlon, Kevin J.; Casey, Clifton C.

2010-01-01

93

Connected Curriculum Project (CCP)  

NSDL National Science Digital Library

The Connected Curriculum Project (CCP) has modules for use in courses from precalculus to linear algebra, differential equations, and engineering mathematics. The project emphasizes mathematical subject areas within biology, chemistry, economics, environmental science, epidemiology and physics. Classroom materials have been classroom tested. In addition to course modules, suitable for a single in-class period, the site contains two longer projects contributed by faculty. Modules use helper applications like Mathcad, Maple, Mathematica or Matlab.

2009-03-01

94

Green Chemistry  

NSDL National Science Digital Library

This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, green chemistry links (including conferences), and an online preview of the ACS-published book Real-World Cases in Green Chemistry are all found at the site. Five video clips on green chemistry from the standpoint of academia, industry, and small business are also featured (Windows Media Player). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students. Check back often for updates.

2002-01-01

95

Final Technical Report for "High-resolution temporal variations in groundwater chemistry: Tracing the links between climate, hydrology, and element mobility in the vadose zone"  

SciTech Connect

In spite of a developing emphasis on geochemical methods in studies of modern hydrologic systems, there have been few attempts to examine temporal fluctuations in groundwater chemistry and element mobility in the near-surface environment. Relatively little is known regarding how groundwaters evolve over 10 to 10,000 year scales, yet this knowledge provides a critical framework for understanding the links between climate and hydrology, the evolution of soils, and element migration in the vadose environment. Recent analytical advances allow U-series measurements to be applied to developing high-resolution chronologies of Pleistocene and Holocene carbonates. The potential of these new tools is examined through an analysis of two well-defined, active karst systems in (1) Barbados and (2) Texas. (1) The research effort on Barbados has developed methods of estimating recharge and inferring the spatial and seasonal distribution of recharge to the Pleistocene limestone aquifer on Barbados. A new method has been developed to estimate recharge based on oxygen isotope variations in rainwater and groundwater. Inter-annual recharge variations indicate that recharge is dependent on the distribution of rainfall throughout the year rather than total annual rainfall. Consequently, a year when rainfall occurs primarily during the peak wet season months (August through November) may have more recharge than a year when rainfall is more evenly distributed through the year. These results lay important groundwork for analysis of rainfall/recharge variations over different time scales based on isotopic records presently being constructed using Barbados speleothems from the same aquifer. (2) The chronology of speleothems (cave calcite deposits) from three caves across 130 kilometers in central Texas provides a 71,000-year record of temporal changes in hydrology and climate. Fifty-three ages were determined by mass spectrometric 238U - 230Th and 235U - 231Pa analyses. The accuracy of the ages and the closed-system behavior of the speleothems are indicated by inter-laboratory comparisons, concordancy of 230Th and 231Pa ages, and the result that all ages are in correct stratigraphic order. Over the last 71,000 years, the stalagmites have similar growth histories with alternating periods of relatively rapid and slow growth. The growth rates vary over more than two orders-of-magnitude, with three periods of rapid growth from 71-60 ka, 39-33 ka, and 24-12 ka. These growth rate shifts correspond in part with global glacial-interglacial climatic shifts. The potential effects of temporal variations in precession of Earth?s orbit on regional effective moisture may provide a mechanism for increased effective moisture coincident with the observed intervals of increased speleothem growth. The stalagmites all exhibit a large drop in growth rate between 15 and 12 ka, and very slow growth up to the present, consistent with drier climate during the Holocene. These results illustrate that speleothem growth rates can reflect the regional response of a hydrologic system to regional and global climate variability.

Jay L. Banner

2002-04-23

96

Zoning Study.  

National Technical Information Service (NTIS)

The study analyzes existing zoned properties in the Shreveport Standard Metropolitan Statistical Area to determine if current development justifies the amount of such zoning. It reviews administrative procedures and policies used in carrying out zoning ch...

1968-01-01

97

Chemistry Notes.  

ERIC Educational Resources Information Center

Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

School Science Review, 1983

1983-01-01

98

Chemistry Notes.  

ERIC Educational Resources Information Center

|Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

School Science Review, 1983

1983-01-01

99

Organic Chemistry  

NSDL National Science Digital Library

R. H. Logan, an chemistry instructor at North Lake College, created this introduction to organic chemistry. The introduction covers a eight types of organic compounds, including Alkanes, Alkyl Halides, and Acyl Compounds (forthcoming); Conformational Analysis and Stereoisomerism; and Instrumental Analysis of Organic Compounds, as well an extensive lesson in general chemistry.

100

Forensic Chemistry  

Microsoft Academic Search

“Forensic chemistry” is a broad term that, if taken literally, would encompass most of the functions within a crime laboratory.\\u000a Techniques used in forensic chemistry are also used by the toxicology and trace analysis sections. However, forensic chemistry\\u000a generally refers to controlled substance or drug analysis.

Donnell Christian

101

Forensic Chemistry  

Microsoft Academic Search

Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is

Suzanne Bell

2009-01-01

102

Chemistry Notes.  

ERIC Educational Resources Information Center

|Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

School Science Review, 1982

1982-01-01

103

CLUSTER CHEMISTRY  

SciTech Connect

Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.

Muetterties, Earl L.

1980-05-01

104

Forensic Chemistry  

NASA Astrophysics Data System (ADS)

Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

Bell, Suzanne

2009-07-01

105

Innovative interdisciplinary approaches in catchment hydrology: on the potential for diatoms and thermal infrared imagery for documenting spatio-temporal dynamics and connectivity of saturated areas in the hillslope-riparian zone-stream system  

NASA Astrophysics Data System (ADS)

Over the past decades, hydrologists have been relentlessly investigating water source, flowpaths and residence time. These issues are of paramount importance when it comes to both the quantitative and qualitative management of water resources. Support from the scientific community has indeed been repeatedly sollicited by the European Union in the context of an optimization of the implementation of its framework directives on water quality and floods. However, to date large uncertainties remain adjunct to our measurements of hydrological processes on the one hand and the modelling of the precipitation-runoff relationship on the other hand. Originally, investigations on the rainfall-runoff transformation were based on conventional geochemical and isotopic tracing techniques. Unfortunately, well-known and documented technical limitations (e.g. non-stable end-members, incomplete mixing assumptions) have rapidly stymied further progress in our understanding of the rainfall-runoff transformation. More recently, technological progress has created new potential for going well beyond the traditional sources of information, such as rainfall and discharge. New measuring techniques have been recently introduced (e.g. thermographic systems such as temperature fiber optic cables and thermal IR cameras for tracing water source and flowpaths, satellite aperture radar for measuring flood extents and/or soil humidity, laser spectrometers for stable isotope measurements, etc.). Indeed the rainfall-runoff transformation inside a catchment is the result of a plethora of interrelated processes that go well beyond water movements. As a consequence, it is crucial to the development of hydrological science to integrate the advances and knowledge from different disciplines. In other terms, knowledge from ecology, biology, as well as other sciences is needed to better understand the functioning of catchments. We need to work together on common problems to find better solutions In recent years, our research activities have been focusing on the exploration of new research avenues for untapping new insights on inherent hydrological processes, guiding water source and flowpaths. Here, we will present the most recent results obtained to date from interdisciplinary proof-of-concept studies carried out in the Weierbach experimental watershed. New research avenues, such as the introduction of terrestrial diatom tracing in flood waves, will hopefully contribute to reduce uncertainties in the determination of the onset/cessation of surface runoff and connectivity in the hillslope-riparian zone-stream system. Likewise, thermal infrared imaging has shown considerable potential for tracing surface water flowpaths, connectivity, as well as saturated area dynamics.

Pfister, L.; Martínez-Carreras, N.; Wetzel, C.; Ector, L.; Frentress, J.; McDonnell, J. J.

2012-04-01

106

Doing Chemistry  

NSDL National Science Digital Library

This website includes over 150 chemistry experiments in the following areas: Atomic Structure, Bonding, Chemical Reactions, Colligative Properties, Condensed States, Electrochemistry, Equilibrium Gases, Instrumentation, Limiting Reactant and more.

Brooks, David W.

2010-05-25

107

Chemistry Notes.  

ERIC Educational Resources Information Center

|Outlines laboratory procedures, demonstrations, teaching suggestions, and content information related to chemistry. Topics include polarizing power; calorimetry and momentum; microcomputers in school chemistry; a constant-volume dispenser for liquids, floating magnets, and crystal lattices; preparation of chromium; and solvent polarity and…

School Science Review, 1981

1981-01-01

108

Teaching Chemistry Using the Movie "Apollo 13."  

ERIC Educational Resources Information Center

|Offers suggestions for incorporating topics that relate to the Apollo 13 space mission into a chemistry course. Discusses connections between the study of chemistry and space exploration, including fuels and oxidants used, reasons for an oxygen tank rupture, and lithium hydroxide-containing carbon dioxide filters. Contains 11 references. (WRM)|

Goll, James G.; Woods, B. J.

1999-01-01

109

Catalytic Chemistry.  

ERIC Educational Resources Information Center

Describes an approach for making chemistry relevant to everyday life. Involves the study of kinetics using the decomposition of hydrogen peroxide by vegetable juices. Allows students to design and carry out experiments and then draw conclusions from their results. (JRH)

Borer, Londa; And Others

1996-01-01

110

Chemistry Notes.  

ERIC Educational Resources Information Center

Describes equipment, activities, and experiments useful in chemistry instruction, including among others, a rapid method to determine available chlorine in bleach, simple flame testing apparatus, and a simple apparatus demonstrating the technique of flash photolysis. (SK)

School Science Review, 1980

1980-01-01

111

Catalytic Chemistry.  

ERIC Educational Resources Information Center

|Describes an approach for making chemistry relevant to everyday life. Involves the study of kinetics using the decomposition of hydrogen peroxide by vegetable juices. Allows students to design and carry out experiments and then draw conclusions from their results. (JRH)|

Borer, Londa; And Others

1996-01-01

112

Nuclear Chemistry.  

ERIC Educational Resources Information Center

Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

Chemical and Engineering News, 1979

1979-01-01

113

Green Chemistry  

NSDL National Science Digital Library

Learn about a study in which participants discovered contaminants in their homes, and how green chemistry may provide alternatives to such everyday toxins, in this video adapted from Contaminated Without Consent.

Foundation, Wgbh E.

2011-03-21

114

Chemistry Notes.  

ERIC Educational Resources Information Center

|Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)|

School Science Review, 1981

1981-01-01

115

Nuclear Chemistry.  

ERIC Educational Resources Information Center

|Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)|

Chemical and Engineering News, 1979

1979-01-01

116

Chemistry Notes  

ERIC Educational Resources Information Center

|Several ideas are proposed for chemistry teachers to try in their classrooms. Subjects included are polymerization of acrylate, polymerization of styrene, conductivity, pollution, preparation of chlorine, redox equations, chemiluminescence, and molecular sieves. (PS)|

School Science Review, 1973

1973-01-01

117

Chemistry Notes.  

ERIC Educational Resources Information Center

|Describes equipment, activities, and experiments useful in chemistry instruction, including among others, a rapid method to determine available chlorine in bleach, simple flame testing apparatus, and a simple apparatus demonstrating the technique of flash photolysis. (SK)|

School Science Review, 1980

1980-01-01

118

Organosilicon Chemistry.  

National Technical Information Service (NTIS)

Several new aspects of the chemistry of silylenes, divalent reactive silicon intermediates, have been explored. Insertion reactions of dimethylsilylene into O-H bonds of primary, secondary, and tertiary alcohols were studied. This provides an efficient ro...

W. P. Weber

1982-01-01

119

Stratospheric chemistry  

SciTech Connect

Advances in stratospheric chemistry made by investigators in the United States from 1987 to 1990 are reviewed. Subject areas under consideration include photochemistry of the polar stratosphere, photochemistry of the global stratosphere, and assessments of inadvertent modification of the stratosphere by anthropogenic activity. Particular attention is given to early observations and theories, gas phase chemistry, Antarctic observations, Arctic observations, odd-oxygen, odd-hydrogen, odd-nitrogen, halogens, aerosols, modeling of stratospheric ozone, and reactive nitrogen effects.

Brune, W.H. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

120

Chemistry Tutorials  

NSDL National Science Digital Library

The California State University Stanislaus developed these interactive chemistry Web tutorials to assist college students in mass spectrometry, proton NMR chemical shifts, and more. With the many animations and figures, visitors will find assistance with the subtraction and absorption of light and with infrared absorption frequencies for numerous compounds. The titration tutorials simulate laboratory experiments without the hazards of dealing with chemicals. Students will also find a very informative lesson describing how to use Excel to record and analyze their chemistry data.

121

Physical Chemistry in Practice: Evaluation of DVD Modules  

ERIC Educational Resources Information Center

The Physical Chemistry in Practice (PCIP) DVD contains video programs (modules) and experimental data that present the research of scientists working in applications of physical chemistry. The DVD allows students to learn about cutting edge research in physical chemistry while making connections to the theoretical concepts learned in lecture.…

Dyer, James U.; Towns, Marcy; Weaver, Gabriela C.

2007-01-01

122

College Connection  

ERIC Educational Resources Information Center

This article describes Oakwood City School District's College Connection Study, which is now in its eighth year. The purpose of the study is to help the educators in the district learn how to effectively prepare students for success in the colleges of their choice. Teachers, administrators, and other staff members travel to colleges to conduct…

Hewitt, Kimberly Kappler; Scalzo, Mary Jo

2012-01-01

123

Getting Connected  

ERIC Educational Resources Information Center

|That the world outside schools is changing faster than ever is old news. Unfortunately, that the world "inside" schools is changing at a glacial pace is even older news. As school leaders, principals have an important choice to make as they move into the second decade of the 21st century. School leaders have a moral obligation to connect and…

Larkin, Patrick

2011-01-01

124

Making Connections.  

ERIC Educational Resources Information Center

|Discusses ways to overcome seventh and eight graders' negative feelings of diversity in the context of a study of the Holocaust. Describes the use of poetry, music and lyrics, and memoirs and novels that reflect a wide range of viewpoints to help students feel more connected to their own world. (LRW)|

Landsman, Julie

1999-01-01

125

New Perspectives on Context-Based Chemistry Education: Using a Dialectical Sociocultural Approach to View Teaching and Learning  

ERIC Educational Resources Information Center

|Context-based chemistry education aims to improve student interest and motivation in chemistry by connecting canonical chemistry concepts with real-world contexts. Implementation of context-based chemistry programmes began 20 years ago in an attempt to make the learning of chemistry meaningful for students. This paper reviews such programmes…

King, Donna

2012-01-01

126

New Perspectives on Context-Based Chemistry Education: Using a Dialectical Sociocultural Approach to View Teaching and Learning  

ERIC Educational Resources Information Center

Context-based chemistry education aims to improve student interest and motivation in chemistry by connecting canonical chemistry concepts with real-world contexts. Implementation of context-based chemistry programmes began 20 years ago in an attempt to make the learning of chemistry meaningful for students. This paper reviews such programmes…

King, Donna

2012-01-01

127

Livelihoods Connect  

NSDL National Science Digital Library

The Department for International Development (DFID), tbe British government agency responsible for promoting economic development and reducing poverty, has created Livelihoods Connect, a Website devoted to "creating sustainable livelihoods to eliminate poverty." Through distance learning materials, traditional online resources, email updates, and online discussions, Livelihoods Connect strives to offer information pertinent and helpful to members of the DFID, those NGOs and consultants working with the DFID, and a host of other NGOs, including the World Bank, the Food and Agriculture Organization, and the International Fund for Agriculture Development. The featured section of the site, Information Resources, offers concise, helpful resources on sustainable livelihoods, including key documents, a Sustainable Livelihood toolbox of draft presentations and project documentation, guidance sheets from the DFID, and distance learning materials. The site also contains information on partnerships and research and an interactive message board.

128

Connecting Organelles  

NSDL National Science Digital Library

This perspective discusses a recent report demonstrating the existence of a complex of proteins connecting mitochondria to the endoplasmic reticulum. Mitochondria are organelles that form a dynamic network in most eukaryotic cell types. Although originally considered to be semi-autonomous powerhouses, they are intimately connected to the rest of the cell through metabolic and signaling pathways, and play a central role in programmed cell death (apoptosis). Sites of close proximity between mitochondria and the tubular network of the endoplasmic reticulum have long been known from electron micrographs, yet their molecular nature remained elusive. In a recent report, Kornmann et al. show that a complex of proteins that controls mitochondrial shape and protein biogenesis bridge these two organelles.

Nils Wiedemann (Universität Freiburg;Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung and Centre for Biological Signalling Studies); Chris Meisinger (Universität Freiburg;Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung and Centre for Biological Signalling Studies); Nikolaus Pfanner (Universität Freiburg;Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung and Centre for Biological Signalling Studies)

2009-07-24

129

Connect Three  

NSDL National Science Digital Library

This problem offers students an opportunity to analyze an interactive Flash game similar to "First Connect Three" (cataloged separately) which involves adding and subtracting positive and negative numbers. This advanced version includes a game board with the integers from -12 to 12. Each player rolls the dice, (one with the numbers 1, 2, 3, â4, â5, â6 and the other with the numbers â1, â2, â3, 4, 5, 6), chooses which number to begin with and whether to add or subtract the other number to produce either a negative or positive result shown on the board. The goal is to be first player to complete a row of three counters either horizontally, vertically or diagonally on the game board. There a link to a resource, "Playing Connect Three" (cataloged separately).

2008-01-01

130

Regional connections  

Microsoft Academic Search

\\u000a The Pantanal is the centre of a whole system of wetlands which are encountered in continental South America. The connections\\u000a with the swamps of the Guaporé were already mentioned above. The wetlands situated to the north and the west of the Pantanal\\u000a are even less known than the Pantanal itself. One fact has to be emphasized, however: these wetlands have

F. D. Por

131

Chemistry Now  

NSDL National Science Digital Library

The National Science Foundation (NSF) recently teamed up with NBC and the National Science Teachers Association to celebrate the International Year of Chemistry. Their big joint project was to create Chemistry Now, a weekly online video series that uncovers and explains the science of common, physical objects. There are over two dozen short films here that cover topics like the chemistry of salt, grapheme, safety glass, and the common cheeseburger. All of the videos are lively and interesting, and they can be used in a wide range of classroom settings to provide visual and audio reinforcement of topics that might be addressed in course lectures and other activities. The videos are completely free and the site includes links to other organizations that have created similar videos.

2012-08-17

132

Lycos Zone  

NSDL National Science Digital Library

In the tradition of Yahooligans (reviewed in the March 22, 1996 Scout Report) and other so-called "green spaces," Lycos has created a new online safe haven for young users which is fairly self-contained, with the exception of the advertisements. (In response to criticisms regarding aggressive marketing to children at similar sites, Lycos claims that the ads are clearly marked and will not collect any personal information.) The site is composed of four sections: the Fun and Games Zone, the Homework Zone, the New and Cool Zone, and an area for parents and teachers. The first two sections are fairly deep, with numerous resources and activities aimed at various age levels. Some links in the Homework Zone lead users outside the site, but they are first presented with a gateway page informing them that they are leaving and offering advice on not divulging personal information.

133

Common Chemistry  

NSDL National Science Digital Library

A web resource that contains Chemical Abstracts Service (CAS) Registry Numbers for approximately 7,800 chemicals of widespread general public interest. Common Chemistry is helpful to non-chemists who know either a name or CAS Registry Number® of a common chemical and want to pair both pieces of information.

Chemical Abstracts Service (CAS)

134

Chemistry Notes  

ERIC Educational Resources Information Center

Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

School Science Review, 1972

1972-01-01

135

Chemistry Notes  

ERIC Educational Resources Information Center

|Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

School Science Review, 1972

1972-01-01

136

Chemistry Notes.  

ERIC Educational Resources Information Center

|Presents chemistry experiments, laboratory procedures, demonstrations, teaching suggestions, and classroom materials/activities. These include: game for teaching ionic formulas; method for balancing equations; description of useful redox series; computer programs (with listings) for water electrolysis simulation and for determining chemical…

School Science Review, 1983

1983-01-01

137

Chemistry Notes.  

ERIC Educational Resources Information Center

|Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

School Science Review, 1983

1983-01-01

138

Green Chemistry  

NSDL National Science Digital Library

This audio segment from PRI's The World Science Podcast explores the science of Green Chemistry. Hear about companies that are developing greener chemicals, and learn why they are fast becoming an attractive alternative for the multi-billion dollar chemical industry.

Foundation, Wgbh E.

2010-02-12

139

Chemistry Notes.  

ERIC Educational Resources Information Center

Presents procedures, experiments, demonstrations, teaching suggestions, and information on a variety of chemistry topics including, for example, inert gases, light-induced reactions, calculators, identification of substituted acetophenones, the elements, analysis of copper minerals, extraction of metallic strontium, equilibrium, halogens, and…

School Science Review, 1982

1982-01-01

140

Confectionary Chemistry.  

ERIC Educational Resources Information Center

|Presents activities and demonstrations that enable teachers to use various types of confections as tactile experiences to spark chemistry students' interest and generate enthusiasm for learning. Presents uses of candy in teaching about atomic structure, spontaneous nuclear decay, chemical formulas, fractoluminescence, the effect of a molecular…

Levine, Elise Hilf

1996-01-01

141

Chemistry Notes.  

ERIC Educational Resources Information Center

|Presents procedures, experiments, demonstrations, teaching suggestions, and information on a variety of chemistry topics including, for example, inert gases, light-induced reactions, calculators, identification of substituted acetophenones, the elements, analysis of copper minerals, extraction of metallic strontium, equilibrium, halogens, and…

School Science Review, 1982

1982-01-01

142

Chemistry's year  

NASA Astrophysics Data System (ADS)

The United Nations has proclaimed 2011 to be the International Year of Chemistry. Under this banner, chemists should seize the opportunity to highlight the rich history and successes of our subject to a much broader audience - and explain how it can help to solve the global challenges we face today and in the future.

2011-01-01

143

Chemistry Notes  

ERIC Educational Resources Information Center

|Describes several chemistry projects, including solubility, formula for magnesium oxide, dissociation of dinitrogen tetroxide, use of 1-chloro-2, 4-dinitrobenzene, migration of ions, heats of neutralizations, use of pocket calculators, sonic cleaning, oxidation states of manganese, and cell potentials. Includes an extract from Chemical Age on…

School Science Review, 1976

1976-01-01

144

Chlorine Chemistry  

NSDL National Science Digital Library

From poolcenter.com comes the Chlorine Chemistry Web site. Ten questions related to chlorine are answered such as What's the History of Chlorine, How Does Chlorine Work to Sanitize, and What Effect Does pH Have on Chlorine. Each is briefly explained in simple and non-technical language.

2008-01-25

145

Chemistry Activities  

NSDL National Science Digital Library

This collection of resource features demonstrations, laboratory investigations, teaching tips, worksheets and other chemistry-related activities. Materials include investigations of mols, nuclear energy, the periodic table, weight and mass, elements, calculations, equations, pH, atomic weight, half-lives, and reactions.

146

Chemistry Gateways and Resources  

NSDL National Science Digital Library

The Chemistry Gateways and Resources collection is comprised of chemistry-related web portals, web sites, and individual digital resources pertaining to many areas of the discipline - general chemistry, organic and inorganic chemistry, physical chemistry, and others - and intended for a wide range of audiences: educators and learners, the general public, and chemistry research communities.

2008-03-14

147

46 CFR 76.27-5 - Zoning.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Electric Fire Detecting System, Details § 76.27-5 Zoning...are easily communicable with the area of the fire-detecting circuit to which they are connected. (3) Systems with...

2012-10-01

148

California Connected  

NSDL National Science Digital Library

Even as public interest programming on television seems to constitute less and less of the average programming schedule, there remain a few bright spots on the dial. One such program is California Connected, which is a public affairs television show that focuses on issues throughout the state of California. The program is produced through a collaboration of four of the state's PBS stations, along with generous assistance from a number of foundations, including The Annenberg Foundation. Visitors can view each show in its entirety on the site, and they may also want to browse the archives, which date back to 2002. There are a number of compelling programs here, including episodes on the efforts to create a solar-hydrogen fuel system and the state of California's biotech industry. If users of the site wish to search the contents of the archive by keyword or topic, they may do so here as well.

149

Resin Chemistry  

Microsoft Academic Search

\\u000a During the ensuing years since the last phenolic resins book was published, many new and remarkable developments have occurred\\u000a in the realm of phenolic chemistry and are given in this chapter.\\u000a \\u000a \\u000a A critical examination of the first step or addition step (methylolation) in the preparation of resoles is described and how\\u000a it can be controlled and compared with the typical

Louis Pilato

2010-01-01

150

Physical Chemistry with a Purpose  

NSDL National Science Digital Library

"The goal of this NSF funded project is to produce a trial set of materials that can be used in physical chemistry courses to more tightly connect the topics introduced in available texts to the realm of modern chemical research." Six modules are currently available at this website, with four more planned by 2006. Each module supplies a reference to a chemistry article, background information, sample questions to stimulate students to think critically about the subject matter, and additional sample chemistry questions. If users are interested in the entire module, they need to contact the author by the email provided. Educators can learn about the teaching approach used in the materials and why the authors feel they are important for education.

Francl, Michelle M.

2005-11-07

151

Physical Chemistry with a Purpose  

NSDL National Science Digital Library

"The goal of this NSF funded project is to produce a trial set of materials that can be used in physical chemistry courses to more tightly connect the topics introduced in available texts to the realm of modern chemical research." Six modules are currently available at this website, with four more planned by 2006. Each module supplies a reference to a chemistry article, background information, sample questions to stimulate students to think critically about the subject matter, and additional sample chemistry questions. If users are interested in the entire module, they need to contact the author by the email provided. Educators can learn about the teaching approach used in the materials and why the authors feel they are important for education.

Francl, Michelle M.

152

Franchise Zone  

NSDL National Science Digital Library

Entrepreneur.com's new service, Franchise Zone, claims to be the "Online Franchise Authority." Featured on the site is Franchise Zone's collection of over 900 franchise opportunities, ranging from financial services to pet businesses. Browseable by name of company as well as by company sector, each franchise is described in detail, including its products or services, company background, costs and fees, number of national and international units, and corporate information. The site also offers news and advice for those looking to buy into a franchise including news-making franchises, the Entrepreneur's Guide to Franchising, an expert advice column, and interactive discussions.

153

(Pesticide chemistry)  

SciTech Connect

This report summarizes a trip by L. W. Barnthouse of the Environmental Sciences Division (ESD), Oak Ridge National Laboratory (ORNL), to Hamburg, Federal Republic of Germany (FRG), where he participated in the 7th International Congress of Pesticide Chemistry. He chaired a workshop on experimental systems for determining effects of pesticides on nontarget organisms and gave an oral presentation at a symposium on pesticide risk assessment. Before returning to the United States, Dr. Barnthouse visited the Netherlands Institute for Sea Research in Texel, the Netherlands.

Barnthouse, L.W.

1990-09-04

154

Organic chemistry on solid surfaces  

NASA Astrophysics Data System (ADS)

Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed.

Ma, Zhen; Zaera, Francisco

2006-07-01

155

Industrial Chemistry and School Chemistry: Making chemistry studies more relevant  

Microsoft Academic Search

In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the context of industrial chemistry

Avi Hofstein; Miri Kesner

2006-01-01

156

Environmental chemistry. Seventh edition  

SciTech Connect

This book presents a basic understanding of environmental chemistry and its applications. In addition to providing updated materials in this field, the book emphasizes the major concepts essential to the practice of environmental chemistry. Topics of discussion include the following: toxicological chemistry; toxicological chemistry of chemical substances; chemical analysis of water and wastewater; chemical analysis of wastes and solids; air and gas analysis; chemical analysis of biological materials and xenobiotics; fundamentals of chemistry; and fundamentals of organic chemistry.

Manahan, S.E. [Univ. of Missouri, Columbia, MO (United States)

1999-11-01

157

Fundamental chemistry of precipitation and mineral scale formation  

Treesearch

Research & Development ... In this paper, the chemistry of precipitation and acid/ base equilibria will be reviewed. The use of the Gibbs Free Energy expression that connects equilibrium constants to enthalpy entropy and temperature will be ...

158

What is Chemistry?  

NSDL National Science Digital Library

Provided by Kiwi Web Chemistry & New Zealand, the "What is Chemistry?" Web site offers a wealth of chemistry information and links. Visitors can read the definition of and link to other sites on inorganic chemistry, organic chemistry, analytical chemistry, physical chemistry, stoichiometry, nuclear chemistry, alchemy, and biochemistry. Other pages of the site explore acids and bases, redox reductions, equations, moles, periodic tables, and more. This extensive and interesting site does a good job of clearly explaining some difficult concepts as well as providing educators and students a good source of other quality sites containing similar content.

Campbell, Allan

159

Astronomical chemistry.  

PubMed

The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic. PMID:21128763

Klemperer, William

2011-01-01

160

Astronomical Chemistry  

NASA Astrophysics Data System (ADS)

The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic.

Klemperer, William

2011-05-01

161

Chemistry 20-30: Background, Exemplars and Resources.  

ERIC Educational Resources Information Center

|This document is designed to provide practical information for teaching the Chemistry 20-30 Program of Studies. The first section provides an overview of Chemistry 20, explaining the program philosophy and the relationships among science, technology, and society. The use of concept connections and teaching a course around major science themes is…

Hackman, Desiree; And Others

162

Visual Experiments Supporting Four Basic Concepts in Chemistry  

Microsoft Academic Search

Visual experiments based on color mixing are proposed to illustrate four basic concepts in chemistry. These visual experiments involve connecting liquid puddles of different colors placed on a flat glass surface and observing and describing the phenomena that occur. Employing as nonspecialized a vocabulary as possible, these experiments can be used as part of a general introduction to chemistry.

François Saint-Antonin

2003-01-01

163

Art and Chemistry: Designing a Study-Abroad Course  

ERIC Educational Resources Information Center

Three related courses examining the connection between chemistry and art have been developed for study-abroad programs in Florence, Italy, by faculty members at Gonzaga University and Mount Saint Mary's University. These courses are described with the intent of providing a general framework for the development of chemistry and art courses in other…

Smieja, Joanne A.; D'Ambruoso, Gemma D.; Richman, Robert M.

2010-01-01

164

Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…

Smith, Andri L.; Tan, Paula

2006-01-01

165

Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

|Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…

Smith, Andri L.; Tan, Paula

2006-01-01

166

Art and Chemistry: Designing a Study-Abroad Course  

ERIC Educational Resources Information Center

|Three related courses examining the connection between chemistry and art have been developed for study-abroad programs in Florence, Italy, by faculty members at Gonzaga University and Mount Saint Mary's University. These courses are described with the intent of providing a general framework for the development of chemistry and art courses in…

Smieja, Joanne A.; D'Ambruoso, Gemma D.; Richman, Robert M.

2010-01-01

167

Radiation Research: Chemistry and Physics.  

National Technical Information Service (NTIS)

Papers in this Proceedings are grouped under the following headings: (1) primary processes in radiation physics and chemistry; (2) radiation chemistry - general chemistry; (3) radiation chemistry - DNA and model systems; (4) radiation chemistry - other mo...

J. J. Broerse G. W. Barendsen H. B. Kal A. J. van der Kogel

1983-01-01

168

The Five Senses of Christmas Chemistry  

ERIC Educational Resources Information Center

|This article describes the organic chemistry of five compounds that are directly associated with the Christmas season. These substances and related materials are presented within the framework of the five senses: silver fulminate (sound), alpha-pinene (sight), sodium acetate (touch), tryptophan (taste), and gingerol (smell). Connections with the…

Jackson, Derek A.; Dicks, Andrew P.

2012-01-01

169

Chemistry for the Public: Our Challenge  

ERIC Educational Resources Information Center

|This article summarizes our experience at McGill University in developing a strong connection not only with a large number of students but also with the general public. This has led to the establishment of a cooperative team to deliver useful information about chemistry and science broadly via the radio, television, the Internet, lectures,…

Harpp, David N.; Fenster, A. E.; Schwarcz, J. A.

2011-01-01

170

The Five Senses of Christmas Chemistry  

ERIC Educational Resources Information Center

This article describes the organic chemistry of five compounds that are directly associated with the Christmas season. These substances and related materials are presented within the framework of the five senses: silver fulminate (sound), alpha-pinene (sight), sodium acetate (touch), tryptophan (taste), and gingerol (smell). Connections with the…

Jackson, Derek A.; Dicks, Andrew P.

2012-01-01

171

The 'wired' universe of organic chemistry.  

PubMed

The millions of reactions performed and compounds synthesized by organic chemists over the past two centuries connect to form a network larger than the metabolic networks of higher organisms and rivalling the complexity of the World Wide Web. Despite its apparent randomness, the network of chemistry has a well-defined, modular architecture. The network evolves in time according to trends that have not changed since the inception of the discipline, and thus project into chemistry's future. Analysis of organic chemistry using the tools of network theory enables the identification of most 'central' organic molecules, and for the prediction of which and how many molecules will be made in the future. Statistical analyses based on network connectivity are useful in optimizing parallel syntheses, in estimating chemical reactivity, and more. PMID:21378798

Grzybowski, Bartosz A; Bishop, Kyle J M; Kowalczyk, Bartlomiej; Wilmer, Christopher E

2009-04-01

172

ACS Green Chemistry Institute  

NSDL National Science Digital Library

This special feature page from the American Chemical Society (ACS) showcases the up-and-coming field of "green chemistry," that is, the development of chemical products and processes that eliminate or reduce the use and generation of hazardous substances. A list of principles behind green chemistry, a searchable bibliography of green chemistry references, and green chemistry links (including conferences). This page comes from ACS's Green Chemistry Project, a three-year educational project to develop and disseminate green chemistry educational materials for graduate and undergraduate chemistry students.

2005-12-13

173

Quick Connect Fastener.  

National Technical Information Service (NTIS)

A quick connect fastener and method of use is presented wherein the quick connect fastener is suitable for replacing available bolts and screws, the quick connect fastener being capable of installation by simply pushing a threaded portion of the connector...

B. Weddendorf

1994-01-01

174

National Chemistry Week 2002: Chemistry Keeps Us Clean JCE Resources for Chemistry and Cleaning  

NASA Astrophysics Data System (ADS)

The claims of cleaning products and personal care items are known to many. National Chemistry Week 2002 makes use of this familiar subject with its theme of "Chemistry Keeps Us Clean". A look back through the Journal of Chemical Education yields many articles connected to this theme. Students can make soap, test the properties of various household cleaners, find out how vacuum cleaners work, and more - all in the name of chemistry. This annotated bibliography collects the best that past issues of the Journal of Chemical Education have to offer for use with this year's National Chemistry Week. Each article has been characterized as a demonstration, experiment, activity, informational, or software/video item; several fit in more than one classification. The most recent articles are listed first. Also included is an evaluation as to which levels the article may serve. Articles that appeared adaptable to other levels, but are not designed explicitly for those levels, are labeled "poss. h.s." "poss. elem.", and so forth.

Jacobsen, Erica K.

2002-10-01

175

Applications of Chemistry Through Climate Science  

NSDL National Science Digital Library

These lessons are intended for a high school chemistry course as stand-alone topics embedded within existing chemistry curriculum. The goal is not to teach the entirety of climate change but rather to give students an understanding of chemistry through the lens of climate change. Additionally, it is intended to provide students with a better view of how science is done, what other careers are available for students besides "research scientist," and to connect their high school chemistry course with the real world. There are eight units within the module including: black carbon, pollution and aerosols, greenhouse gases, science and careers, isotopes and ice cores, ozone, societal impacts of climate change, and finding solutions to climate change. Each has a unique activity for the students (i.e. jigsaw reading, lab experiments, comic strips, Socratic seminar, etc) and any information given to students is visually-driven (pictures, animations, videos, etc).

2012-01-01

176

Exploring visuospatial thinking in chemistry learning  

NASA Astrophysics Data System (ADS)

In this article, we examine the role of visuospatial cognition in chemistry learning. We review three related kinds of literature: correlational studies of spatial abilities and chemistry learning, students' conceptual errors and difficulties understanding visual representations, and visualization tools that have been designed to help overcome these limitations. On the basis of our review, we conclude that visuospatial abilities and more general reasoning skills are relevant to chemistry learning, some of students' conceptual errors in chemistry are due to difficulties in operating on the internal and external visuospatial representations, and some visualization tools have been effective in helping students overcome the kinds of conceptual errors that may arise through difficulties in using visuospatial representations. To help students understand chemistry concepts and develop representational skills through supporting their visuospatial thinking, we suggest five principles for designing chemistry visualization tools: (1) providing multiple representations and descriptions, (2) making linked referential connections visible, (3) presenting the dynamic and interactive nature of chemistry, (4) promoting the transformation between 2D and 3D, and (5) reducing cognitive load by making information explicit and integrating information for students.

Wu, Hsin-Kai; Shah, Priti

2004-05-01

177

Social connection enables dehumanization  

Microsoft Academic Search

Being socially connected has considerable benefits for oneself, but may have negative consequences for evaluations of others. In particular, being socially connected to close others satisfies the need for social connection, and creates disconnection from more distant others. We therefore predicted that feeling socially connected would increase the tendency to dehumanize more socially distant others. Four experiments support this prediction.

Adam Waytz; Nicholas Epley

178

Temperate Oceans: Light Zones  

NSDL National Science Digital Library

This reference provides an overview of the three zones into which the ocean can be divided based on the amount of light recieved: the sunlit (or euphotic) zone, the twilight (or disphotic) zone, and the midnight (or aphotic) zone. The descriptions are accompanied by diagrams and a brief listing of the organisms that live in each zone.

179

Hamiltonian Connected Line Graphs  

Microsoft Academic Search

Abstract A graph G is hamiltonian-connected if any two of its vertices are connected by a Hamilton path (a path including every vertex of G); and G is s-hamiltonian-connected if the deletion of any vertex subset with at most s vertices results in a hamiltonian-connected graph. In this paper, we prove that the line graph of a (t + 4)-edge-connected

Deng-Xin Li; Hong-jian Lai; Ye-Hong Shao; Mingquan Zhan

2007-01-01

180

Linking Lu-Hf geochronology and garnet chemistry in eclogites of the Sulu UHP terrane, China. Implications for punctuated garnet growth events and interpretation of element zoning patterns regarding geochronology  

NASA Astrophysics Data System (ADS)

The Lu-Hf isotope system has become an increasingly powerful and often used tool to date garnet-bearing assemblages in metamorphic rocks. Together with thorough investigation of major and trace element distributions in garnet it is possible e.g. to date garnet growth stages, and in conjunction link the petrological and geochemical characteristics of garnet to a P-T-t history. Here we present new Lu-Hf garnet-clinopyroxene isochron ages for five eclogites from the Chinese Scientific Drilling Project drill core. These ages define a narrow time frame for eclogitisation in these rocks between 215.8 and 220.5 Ma. Garnets in these eclogite samples retain a typical core-rim zoning of Lu (and other heavy rare earth elements), indicative of patterns generated during prograde growth, whereas the same garnets have homogeneous major element distributions. Later resorption and re-growth of garnet grains is not visible based on the HREE distributions in these garnets. This points to a mechanism where differences in the diffusional behavior of elements with low and high charges (e.g. Mn2+ diffuses faster than Lu3+), coupled with differences in their partition coefficients and element availability during growth, influence the generation, preservation and resetting of growth patterns. Data from this study as well as from other published Lu-Hf ages for eclogites of the Qinling-Dabie-Sulu UHP terrane show that eclogitisation, and possibly the time frame for UHP metamorphism, was short on small regional scales. However, spanning the whole length of the UHP belt, these Lu-Hf ages form a continuum of nearly 50 Ma. We will also discuss the effect of zircon inclusions in garnet to Lu-Hf chronology if Hf was leached from zircon during dissolution. In the case of one eclogite sample with a high abundance of inherited zircons it shows that, although Hf was leached from zircon, three different garnet separates fit on a well defined isochron with a low MSWD. However, this age is slightly older (220.5 ± 2.7 Ma) than the average of the other four samples (216.9 ± 1.2 Ma), yet the isochron age is close to this average within error.

Schmidt, A.; Mezger, K.; O'Brien, P. J.

2010-12-01

181

Marginal Zone Lymphoma  

MedlinePLUS

Marginal Zone Lymphoma Overview Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma (HL) ... types of marginal zone lymphoma: Extranodal marginal zone lymphoma or mucosa-associated lymphoid tissue (MALT) is the ...

182

The bottom intertidal zone  

NSDL National Science Digital Library

The bottom intertidal area remains under water except during low tides. This zone is most abundant of the intertidal zones and contains seaweeds and other plants, invertebrates, and fishes. The bottom zone is subject to the most intense wave action.

Katie Hale (CSUF;Biological Sciences)

2007-06-08

183

Zone separator for multiple zone vessels  

DOEpatents

A solids-gas contact vessel, having two vertically disposed distinct reaction zones, includes a dynamic seal passing solids from an upper to a lower zone and maintaining a gas seal against the transfer of the separate treating gases from one zone to the other, and including a stream of sealing fluid at the seal.

Jones, John B. (Grand Junction, CO)

1983-02-01

184

Collaborative Physical Chemistry Projects Involving Computational Chemistry  

Microsoft Academic Search

The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes.

David M. Whisnant; Jerry J. Howe; Lisa S. Lever

2000-01-01

185

Special Report: Brain Chemistry.  

ERIC Educational Resources Information Center

Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

Krassner, Michael B.

1983-01-01

186

Chemistry of Americium.  

National Technical Information Service (NTIS)

Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, s...

W. W. Schulz

1976-01-01

187

Environmental chemistry: Volume A  

SciTech Connect

This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

Yen, T.F.

1999-08-01

188

Aquatic Chemistry, Third Edition  

NASA Astrophysics Data System (ADS)

Most water scientists and environmental engineers will recognize this classic environmental chemistry text as “Stumm and Morgan” rather than Aquatic Chemistry. Publication of the first edition in 1970 established a standard for books dealing with environmental chemistry in terms of depth and breadth of coverage. Scientists and engineers concerned with issues of water quality are well advised to have Aquatic Chemistry as part of their personal libraries, or at least in their office libraries.

Schroeder, Edward D.; Young, Thomas M.

189

Mechanisms in Photographic Chemistry  

ERIC Educational Resources Information Center

Reviews current research interests in photographic chemistry, involving two proposed models for spectral sensitization of crystal defects and impurities in the photolysis reactivity and the mechanisms of development and complexation. Establishment of photographic chemistry in a chemistry curriculum is recommended. (CC)

Sahyun, M. R. V.

1974-01-01

190

Green Chemistry and Education.  

ERIC Educational Resources Information Center

|Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)|

Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

2000-01-01

191

Green Chemistry and Education.  

ERIC Educational Resources Information Center

Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

2000-01-01

192

Mechanisms in Photographic Chemistry  

ERIC Educational Resources Information Center

|Reviews current research interests in photographic chemistry, involving two proposed models for spectral sensitization of crystal defects and impurities in the photolysis reactivity and the mechanisms of development and complexation. Establishment of photographic chemistry in a chemistry curriculum is recommended. (CC)|

Sahyun, M. R. V.

1974-01-01

193

Chemistry on Stamps.  

ERIC Educational Resources Information Center

|Suggests how postage stamps can be incorporated into chemistry teaching. Categories considered include emergence of chemistry as a science, metric system, atoms (and molecules and ions), stoichiometry, energy relationships in chemical systems, chemical bonding, nuclear chemistry, biochemistry, geochemistry, matter (gases, liquids, and solids),…

Schreck, James O.

1986-01-01

194

Aquatic Chemistry, Third Edition  

Microsoft Academic Search

Most water scientists and environmental engineers will recognize this classic environmental chemistry text as ``Stumm and Morgan'' rather than Aquatic Chemistry. Publication of the first edition in 1970 established a standard for books dealing with environmental chemistry in terms of depth and breadth of coverage. Scientists and engineers concerned with issues of water quality are well advised to have Aquatic

Edward D. Schroeder; Thomas M. Young

1996-01-01

195

Analytical chemistry instrumentation  

Microsoft Academic Search

Separate abstracts were prepared for 48 papers in these conference proceedings. The topics covered include: analytical chemistry and the environment; environmental radiochemistry; automated instrumentation; advances in analytical mass spectrometry; Fourier transform spectroscopy; analytical chemistry of plutonium; nuclear analytical chemistry; chemometrics; and nuclear fuel technology. (LEW)

Laing

1986-01-01

196

Root Apex Transition Zone As Oscillatory Zone  

PubMed Central

Root apex of higher plants shows very high sensitivity to environmental stimuli. The root cap acts as the most prominent plant sensory organ; sensing diverse physical parameters such as gravity, light, humidity, oxygen, and critical inorganic nutrients. However, the motoric responses to these stimuli are accomplished in the elongation region. This spatial discrepancy was solved when we have discovered and characterized the transition zone which is interpolated between the apical meristem and the subapical elongation zone. Cells of this zone are very active in the cytoskeletal rearrangements, endocytosis and endocytic vesicle recycling, as well as in electric activities. Here we discuss the oscillatory nature of the transition zone which, together with several other features of this zone, suggest that it acts as some kind of command center. In accordance with the early proposal of Charles and Francis Darwin, cells of this root zone receive sensory information from the root cap and instruct the motoric responses of cells in the elongation zone.

Baluska, Frantisek; Mancuso, Stefano

2013-01-01

197

Root apex transition zone as oscillatory zone.  

PubMed

Root apex of higher plants shows very high sensitivity to environmental stimuli. The root cap acts as the most prominent plant sensory organ; sensing diverse physical parameters such as gravity, light, humidity, oxygen, and critical inorganic nutrients. However, the motoric responses to these stimuli are accomplished in the elongation region. This spatial discrepancy was solved when we have discovered and characterized the transition zone which is interpolated between the apical meristem and the subapical elongation zone. Cells of this zone are very active in the cytoskeletal rearrangements, endocytosis and endocytic vesicle recycling, as well as in electric activities. Here we discuss the oscillatory nature of the transition zone which, together with several other features of this zone, suggest that it acts as some kind of command center. In accordance with the early proposal of Charles and Francis Darwin, cells of this root zone receive sensory information from the root cap and instruct the motoric responses of cells in the elongation zone. PMID:24106493

Baluška, František; Mancuso, Stefano

2013-10-02

198

Connecting to the World  

Microsoft Academic Search

The Duke University School of Law Library connected its Student Research Network to the Internet. The article explains the mechanics of the connection and the benefits of utilizing the Internet. Sources for information and of useful software are included.

Kenneth J. Hirsh

1994-01-01

199

Undifferentiated Connective Tissue Disease  

MedlinePLUS

... vessels. Examples of connective tissue diseases include lupus , scleroderma , rheumatoid arthritis , Sjögren's syndrome , myositis , and vasculitis . There ... connective tissue diseases, such as lupus, Sjögren's or scleroderma. More UCTD Information Overview Causes Symptoms Diagnosis Treatment ...

200

78 FR 55684 - ConnectED Workshop  

Federal Register 2010, 2011, 2012, 2013

...integrate Web video and other digital content into the curriculum; and as classroom management software tools move everything from homework assignments to testing into the cloud. The workshop will explore possible strategies to connect virtually all of our...

2013-09-11

201

Alcohol, Chemistry and You  

NSDL National Science Digital Library

Developed by Kennesaw State University, ChemCases.com is a series of curriculum units that link responsible decision making in product development with chemical principles taught in college General Chemistry. Alcohol, Chemistry and You, by Dr. Bill Boggan, is the latest offering by the Web site, which "looks at the chemistry of beverage alcohol (ethyl alcohol) through the eyes of a General Chemistry student." The fourteen chapter lessons cover everything from what ethyl alcohol is to alcohol addiction, relating it to various principles learned in a general chemistry course.

2001-01-01

202

Subsea pipeline connection  

SciTech Connect

A method is described for connecting and laying a flowline from a subsea structure on the seafloor comprising: connecting the flowline from a first vessel to a riser from a second vessel; deploying the flowline and riser downwardly to the subsea structure; connecting the riser to the subsea structure; connecting the flowline to the subsea structure; laying the flowline on the seafloor from the subsea structure; and disconnecting the riser from both the flowline and the subsea structure.

Langer, C.G.

1986-05-13

203

Planning a Connected Curriculum.  

ERIC Educational Resources Information Center

|This book offers strategies to help teachers and curriculum coordinators strengthen student interest through meaningful and purposeful learning. The 15 chapters are: (1) "Introduction: Planning a Connected Curriculum"; (2) "Children, School, and Community"; (3) "On Connections"; (4) "Making Connections: An Interdisciplinary Approach"; (5) "Making…

Wisconsin State Dept. of Public Instruction, Madison.

204

Vadose zone microbiology  

SciTech Connect

The vadose zone is defined as the portion of the terrestrial subsurface that extends from the land surface downward to the water table. As such, it comprises the surface soil (the rooting zone), the underlying subsoil, and the capillary fringe that directly overlies the water table. The unsaturated zone between the rooting zone and the capillary fringe is termed the "intermediate zone" (Chapelle, 1993). The vadose zone has also been defined as the unsaturated zone, since the sediment pores and/or rock fractures are generally not completely water filled, but instead contain both water and air. The latter characteristic results in the term "zone of aeration" to describe the vadose zone. The terms "vadose zone," "unsaturated zone", and "zone of aeration" are nearly synonymous, except that the vadose zone may contain regions of perched water that are actually saturated. The term "subsoil" has also been used for studies of shallow areas of the subsurface immediately below the rooting zone. This review focuses almost exclusively on the unsaturated region beneath the soil layer since there is already an extensive body of literature on surface soil microbial communities and process, e.g., Paul and Clark (1989), Metting (1993), Richter and Markowitz, (1995), and Sylvia et al. (1998); whereas the deeper strata of the unsaturated zone have only recently come under scrutiny for their microbiological properties.

Kieft, Thomas L.; Brockman, Fred J.

2001-01-17

205

Chemistry explained by topology: an alternative approach.  

PubMed

Molecular topology can be considered an application of graph theory in which the molecular structure is characterized through a set of graph-theoretical descriptors called topological indices. Molecular topology has found applications in many different fields, particularly in biology, chemistry, and pharmacology. The first topological index was introduced by H. Wiener in 1947 [1]. Although its very first application was the prediction of the boiling points of the alkanes, the Wiener index has demonstrated since then a predictive capability far beyond that. Along with the Wiener index, in this paper we focus on a few pioneering topological indices, just to illustrate the connection between physicochemical properties and molecular connectivity. PMID:21375503

Galvez, Jorge; Villar, Vincent M; Galvez-Llompart, Maria; Amigó, José M

2011-05-01

206

General Chemistry Online!  

NSDL National Science Digital Library

General Chemistry Online, created by Frederick Senese, a professor at Frostburg State University, is a guide and resource for introductory chemistry students. This site provides five areas of information: The Chemistry Home Companion, Just Ask Antoine!, Chemistry Exam Survival Guide, Tutorials, and a Featured Article. The Companion is a study guide covering the basic concepts of an introductory general chemistry course. Topics include measurement, molecules and compounds, and the quantum theory. Just Ask Antoine! allows students to post their chemistry questions. An archived list provides questions and answers for the past year. The Exam Survival Guide provides tips on passing exams, checklists of objectives and skills, and two online practice exams. The Tutorial currently contains only problems and quizzes for the measurement topic. The featured article for February is about Anandamide, a "messenger molecule that plays a role in pain, depression, appetite, memory, and fertility."

Senese, Frederick A.

207

[The high-pressure chemistry, barophysiological chemistry, comparative enzymology of cholinesterase the 100th anniversary from the birth of A. P. Brestkin].  

PubMed

There are exposed the main landmarks of the scientific biography of Professor Aleksandr Pavlovich Brestkin, connected with his investigations in the field of chemistry of high pressures, physiological chemistry of caisson disease, kinetics of esterase catalysis, and in comparative enzymology of cholinesterases. PMID:23013018

Rozengart, E V

208

Middle School Chemistry  

NSDL National Science Digital Library

Middle school science resource from ACS. It includes activity-based lesson plans for teaching basic chemistry concepts that cover all the main concepts in middle school chemistry. Each lesson also contains integrated animations and video that a teacher can use to help explain student observations on the molecular level. Online professional development will also be available to introduce and familiarize teachers with the demonstrations, activities, and chemistry content in the site.

209

Kurnakov and analytical chemistry  

Microsoft Academic Search

The paper appreciates the role of Academician N.S. Kurnakov in holding the All-Union Conference on Analytical Chemistry (1939)\\u000a and creating the Commission on Analytical Chemistry at the Academy of Sciences of the USSR. The scientific works of Kurnakov\\u000a relating to chemical analysis are indicated; brief review is given to studies on analytical chemistry that were carried out\\u000a in the collectives

Yu. A. Zolotov

2010-01-01

210

Science Update: Analytical Chemistry.  

ERIC Educational Resources Information Center

|Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)|

Worthy, Ward

1980-01-01

211

Environmental chemistry: Volume B  

SciTech Connect

This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume B include equilibria processes, chemical processes, biochemical processes, and physicochemical processes.

Yen, T.F.

1999-08-01

212

Open access and medicinal chemistry  

PubMed Central

Chemistry Central is a new open access website for chemists publishing peer-reviewed research in chemistry from a range of open access journals. A new addition, Chemistry Central Journal, will cover all of chemistry and will be broken down into discipline-specific sections, and Im delighted that Medicinal Chemistry will be a key discipline in this new journal.

Swain, Chris

2007-01-01

213

Coupled Hydrological and Geochemical Processes Governing the Fate and Transport of Radionuclides and Toxic Metals in the Hanford Vadose Zone  

SciTech Connect

At the D.O.E. Hanford Reservation, accelerated migration of radionuclides has been observed in the vadose zone underlying the tank farms. Our goal is to provide an improved understanding and predictive capability of the coupled hydrogeochemical mechanisms responsible for observed migration. Our approach is to perform a suite of experiments ranging from novel surface interrogation techniques (e.g., XAS) to miscible displacement experiments on disturbed and undisturbed sediments from the Hanford, Plio-Pleistocene and Ringold formations. Results indicate during unsaturated conditions hydrologic processes governing transport are a strong function of sediment layering in the Hanford and Ringold formations. The transport of radionuclides and toxic metals (U, Cr(VI), Cs, Sr and Co) is influenced by reactive geochemical nonequilibrium, sedimentary mineralogy and solution chemistry. This research will provide new insights into how physical and mineralogical heterogeneities (e.g. stratification, pore regime connectivity, mineral composition along flowpaths) influence contaminant retardation and degree of geochemical nonequilibrium during transport.

Mayes, M.A.; Jardine, P.M.; Fendorf, S.E.; Pace, M.N.; Yin, X.; Mehlhorn, T.L.; Zachara, J.M.

2003-03-27

214

Cerebellar zones: a personal history.  

PubMed

Cerebellar zones were there, of course, before anyone noticed them. Their history is that of young people, unhindered by preconceived ideas, who followed up their observations with available or new techniques. In the 1960s of the last century, the circumstances were fortunate because three groups, in Leiden, Lund, and Bristol, using different approaches, stumbled on the same zonal pattern in the cerebellum of the cat. In Leiden, the Häggqvist myelin stain divulged the compartments in the cerebellar white matter that channel the afferent and efferent connections of the zones. In Lund, the spino-olivocerebellar pathways activated from individual spinal funiculi revealed the zonal pattern. In Bristol, charting the axon reflex of olivocerebellar climbing fibers on the surface of the cerebellum resulted in a very similar zonal map. The history of the zones is one of accidents and purposeful pursuit. The technicians, librarians, animal caretakers, students, secretaries, and medical illustrators who made it possible remain unnamed, but their contributions certainly should be acknowledged. PMID:20967577

Voogd, Jan

2011-09-01

215

Real World Graph Connectivity  

ERIC Educational Resources Information Center

We present the topic of graph connectivity along with a famous theorem of Menger in the real-world setting of the national computer network infrastructure of "National LambdaRail". We include a set of exercises where students reinforce their understanding of graph connectivity by analysing the "National LambdaRail" network. Finally, we give…

Lind, Joy; Narayan, Darren

2009-01-01

216

Connecting assembly and method  

Microsoft Academic Search

An apparatus and methods are described for making underwater connection of marine riser assemblies which have controlled buoyancy. Methods of assembling and using such riser assemblies in underwater drilling operations also are described. A connecting assembly communicates between a first location and a second location lower than the first location, with the 2 locations separated by a fluid body. A

Wardlaw; H. W. R

1978-01-01

217

Caldecott Connections to Science.  

ERIC Educational Resources Information Center

|This volume brings award-winning literature to all areas of the science curriculum. The lesson plan format includes the four stages of engagement, elaboration, exploration, and connection. Each story is followed by activities that make connections between literature, science, and the arts. Chapters include: (1) "Frog Went A-Courtin'," which…

Glandon, Shan

218

The Gibbs Street Connection.  

ERIC Educational Resources Information Center

Discusses the Gibbs Street Connection, a professional development program for music educators and a collaborative effort between the Eastman School of Music and the Rochester (New York) Philharmonic Orchestra. Highlights efforts to evaluate the Gibbs Street Connection and the benefits of the program. Offers tips for beginning such programs and…

McCusker, Joan

1999-01-01

219

Connecting Arithmetic to Algebra  

ERIC Educational Resources Information Center

|Algebraic thinking is a top priority in mathematics classrooms today. Because elementary school teachers lay the groundwork to develop students' capacity to think algebraically, it is crucial for teachers to have a conceptual understanding of the connections between arithmetic and algebra and be confident in communicating these connections. Many…

Darley, Joy W.; Leapard, Barbara B.

2010-01-01

220

Basic Chemistry Review  

NSDL National Science Digital Library

This assignment reviews basic of chemistry for students who should have had 2 introductory semesters of basic chemistry prior to enrolling in the Fundamental of Water Quality course for which the assignment is used. Assignment reviews basic equation balancing and questions about valence and concentration conversion that students will confront regularly in any geochemistry course.

Meixner, Thomas

221

Tropospheric Halogen Chemistry  

Microsoft Academic Search

Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing

R. von Glasow; P. J. Crutzen

2003-01-01

222

WATER CHEMISTRY ASSESSMENT METHODS  

EPA Science Inventory

This section summarizes and evaluates the surfce water column chemistry assessment methods for USEPA/EMAP-SW, USGS-NAQA, USEPA-RBP, Oho EPA, and MDNR-MBSS. The basic objective of surface water column chemistry assessment is to characterize surface water quality by measuring a sui...

223

Chemistry in Microfluidic Channels  

ERIC Educational Resources Information Center

|General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets…

Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

2011-01-01

224

Brushing Up on Chemistry.  

ERIC Educational Resources Information Center

Presents an activity designed for use during National Chemistry Week 2002 with the theme "Chemistry Keeps Us Clean". Allows students to discover more about a cleaning product they use everyday. Students make their own toothpaste and compare its properties with those of commercial toothpaste. (MM)

Trantow, Ashley

2002-01-01

225

Infrared Lasers in Chemistry.  

ERIC Educational Resources Information Center

|Selected infrared laser chemistry topics are discussed including carbon dioxide lasers, infrared quanta and molecules, laser-induced chemistry, structural isomerization (laser purification, sensitized reactions, and dielectric breakdown), and fundamental principles of laser isotope separation, focusing on uranium isotope separation. (JN)|

John, Phillip

1982-01-01

226

Laser applications in chemistry  

SciTech Connect

This book contains the proceedings from SPIE - The International Society for Optical Engineering conference on June 5-6, 1986. Topics are presented under the following session heads: Isotope Separation and Related Photochemistry, Laser Induced Chemistry I, Laser Spectroscopy, and Laser Induced Chemistry II. There are 33 papers in this volume.

Evans, D.K.

1986-01-01

227

Rolf Claessen's Chemistry Index  

NSDL National Science Digital Library

This award is given to sites, that somehow are related to chemistry. The criteria to rank the sites are information content and design (layout, navigation, graphical design). Sites must contain chemistry related topics as innovative and attractive as possible. This award is given away to the best 5% of the submissions to the website and other sites reviewed by site author.

228

Brushing Up on Chemistry.  

ERIC Educational Resources Information Center

|Presents an activity designed for use during National Chemistry Week 2002 with the theme "Chemistry Keeps Us Clean". Allows students to discover more about a cleaning product they use everyday. Students make their own toothpaste and compare its properties with those of commercial toothpaste. (MM)|

Trantow, Ashley

2002-01-01

229

Analogies in chemistry textbooks  

Microsoft Academic Search

This study combines a critical analysis of analogies found in eight chemistry textbooks used by Australian senior high school students with the views of the textbook authors about analogies in chemistry textbooks and teaching. Sixty?two analogies were identified which described abstract chemical concepts such as atomic structure and collision theory. A range of styles, including pictorial analogies, were identified and

Rodney B. Thiele; David F. Treagust

1995-01-01

230

Chemistry and Biology  

ERIC Educational Resources Information Center

|Discusses the relationship between chemisty and biology in the science curriculum. Points out the differences in perception of the disciplines, which the physical scientists favoring reductionism. Suggests that biology departments offer a special course for chemistry students, just as the chemistry departments have done for biology students.…

Wigston, David L.

1970-01-01

231

Chemistry of americium  

Microsoft Academic Search

Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

Schulz

1976-01-01

232

Chlorine Chemistry Division  

NSDL National Science Digital Library

This site is provided by the American Chemistry Council's Chlorine Chemistry Division. The page contains several links that give an introduction to chlorine, its uses, and issues surrounding the chemical compound. There is also a link to the Chlorine Science Center which provides classroom activities and a chlorine compound of the month.

2008-01-02

233

High Energy Halogen Chemistry.  

National Technical Information Service (NTIS)

Contents: Nitrosilicone Chemistry; Chemistry of 2-Fluoro-2-nitropropanediol; Experimental -- Bis(2-fluoro-2,2-dinitropropyl)silanediols; Reaction of bis(2-fluoro-2, 2-dinitropropyl) silanediol with chlorotrimethylsilane, Bis(3-3-fluoro-3,3-dinitropropyl)p...

K. Baum P. T. Berkowitz D. A. Lerdal

1978-01-01

234

Synthetic biology for synthetic chemistry.  

PubMed

The richness and versatility of biological systems make them ideally suited to solve some of the world's most significant challenges, such as converting cheap, renewable resources into energy-rich molecules; producing high-quality, inexpensive drugs to fight disease; and remediating polluted sites. Over the years, significant strides have been made in engineering microorganisms to produce fuels, bulk chemicals, and valuable drugs from inexpensive starting materials; to detect and degrade nerve agents as well as less toxic organic pollutants; and to accumulate metals and reduce radionuclides. The components needed to engineer the chemistry inside a microbial cell are significantly different from those commonly used to overproduce pharmaceutical proteins. Synthetic biology has had and will continue to have a significant impact on the development of these components to engineer cellular metabolism and microbial chassis to host the chemistry. The ready availability of more well-characterized gene expression components and hosts for chemical synthesis, standards for the connection of these components to make larger functioning devices, computer-aided design software, and debugging tools for biological designs will decrease both the time and the support needed to construct these designs. Some of the most important tools for engineering bacterial metabolism and their use for production of the antimalarial drug artemisinin are reviewed. PMID:18205292

Keasling, Jay D

2008-01-18

235

Connect-ED: Higher Education Information Exchange  

NSDL National Science Digital Library

St. John's University offers this distribution-only information service for and about institutions of higher education. Connect-ED was established to disseminate information about the programs, schools, faculties and courses of study of post-secondary institutions, schools of higher learning, or tertiary educational institutes, in order to assist subscribers in decisions regarding recruitment and selection. The list will be of particular interest to education administrators; faculty; information, public relations or recruitment officers; students; and potential employers. The material posted on this list might include: notices of new, established, or unique programs; special events, publications, and media coverage; conferences, meetings, faculty or institutional awards; changes in educational standards, admission criteria, or curricula; fees; scholarship availability; accreditation reports; calls for papers; application deadlines; degree requirements; credit balancing; and course delivery (traditional, on-line, Internet, teleconference or other methods).

1998-01-01

236

Links between worlds: Unraveling migratory connectivity  

USGS Publications Warehouse

Migration is the regular seasonal movement of animals from one place to another, often from a breeding site to a nonbreeding site and back. Because the act of migration makes it difficult to follow individuals and populations year round, our understanding of the ecology and evolution of migrating organisms, particularly birds, has been severely impeded. Exciting new advances in satellite telemetry, genetic analyses and stable isotope chemistry are now making it possible to determine the population and geographical origin of individual birds. Here, we review these new approaches and consider the relevance of understanding migratory connectivity to ecological, evolutionary and conservation issues.

Webster, M.; Marra, P. P.; Haig, Susan M.; Bensch, S.; Holmes, R. T.

2002-01-01

237

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone  

Code of Federal Regulations, 2012 CFR

...Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries...ZONE OFF ALASKA Pt. 679, Table 51 Table 51 to Part 679âModified Gear Trawl Zone...00 W 60 06.15 N Note: The area is delineated by connecting...

2012-10-01

238

50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone  

Code of Federal Regulations, 2011 CFR

...Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries...ZONE OFF ALASKA Pt. 679, Table 51 Table 51 to Part 679âModified Gear Trawl Zone...00 W 60 06.15 N Note: The area is delineated by connecting...

2011-10-01

239

EVOLVING FROM GREEN CHEMISTRY TO SUSTAINABLE CHEMISTRY  

EPA Science Inventory

The twelve principles of green chemistry provide a foundation and pathway which allows researchers to incorporate greenness into existing reactions or when developing new technologies. Research from our laboratory has adopted many of these principles and utlizes them as a major c...

240

Do Not Only Connect  

NASA Astrophysics Data System (ADS)

Although the concept of connectivity has been increasingly canvassed in the last 10 years, there have been relatively few, and sometimes contradictory operational definitions. Connectivity can be reasonably associated with water flow, sediment transport and ecological habitats, and either generally or along specific pathways, for example in hyporheic exchanges, and inherits a legacy from concepts such as contributing area and hydraulic routing. Here we focus on a single mode, for overland flow, but there remain a bewildering range of operational definitions. Connectivity between two points A and B, on a flow line, can be described as a nominal variable (presence or absence of connection), as a scalar (time delay or breakthrough volume), or as increasingly complex vectors (hydrograph at B for given input at A), even at steady state for a conservative system. Detailed descriptions of dynamic connectivity between adjacent points across an area form one critical ingredient of fine scale process-based models, such as CRUM or MAHLERAN. In this way, connectivity provides a valuable way of conceptualizing the local persistence and continuity of overland flow, particularly in semi-arid areas with short bursts of rainfall and patchy surface properties. For time-spans over which the soils and topography can respond, the division between structural and functional connectivity is also valuable; structure providing a necessary pre-condition for functional connection, and function a necessary condition for change in structure. Beyond the strictly local scale, we would like to collapse the detail of overland flow connectivity into summary index variables, providing one or a few parameters that, for example, scale the response of a hillslope or small catchment to storm rainfall. Candidate indices include average travel times from runoff generating cells, average residence times and contributing areas, all potentially time-varying in response to catchment condition and storm rainfall. However, no magic bullet has yet emerged to summarize the complexity of catchment response.

Kirkby, M. J.

2012-04-01

241

An Investigation of the Value of Using Concept Maps in General Chemistry  

Microsoft Academic Search

This paper reports a qualitative investigation of the effects of integrating concept maps into the freshman-level general chemistry curriculum. Ten volunteers each from two sections of general chemistry for science majors were interviewed to assess the degree to which they connected concepts from different domains. The sections were equivalent except for the integration of concept maps into one section. Concept

Gayle Nicoll; Joseph S. Francisco; Mary B. Nakhleh

2001-01-01

242

Learning Chemistry in Laboratory Settings: A Hands-on Curriculum for Non-Science Majors.  

ERIC Educational Resources Information Center

|This curriculum consists of a series of Learning Activity Packets (LAPs) on the chemistry involved in different aspects of modern society. It is intended for non-majors and introduces fundamental concepts by engaging students in hands-on learning activities. The LAPs are designed to make connections between chemistry and other fields of interest…

Wang, Rachel

243

Secondary porosity in a transient vadose zone  

SciTech Connect

The Western New York Nuclear Service Center is the site of low and high level radioactive waster buried in a series of trenches excavated in a 28 m thick, Lavery-age silty clay diamicton that exhibits a 6 meter thick transient vadoes zone where exposed at the surface. Hydrostratigraphy of this till includes a 0.25 m thick poorly developed macroporous soil, a 3.5 m thick weathered zone of densely spaced and randomly orientated horizontal and vertical fractures, a 2 m thick unweathered zone of intermittently spaced fractures exhibiting east-west orientations, and a massive 23 m thick unweathered till zone that exhibits isolated, east-west orientated fractures. Bulk hydraulic conductivity of this active flow zone decreases with depth from 10[sup [minus]5] to 10[sup [minus]8] cm/s. The specific discharge of vertically flowing groundwater in the massive till zone is 1.25 cm/yr. A water surplus in the recharge season saturates the fractured zone to grade with up to 7.37 cm/yr of net infiltration. Tritium and radionuclides from the waste trenches and surrounding soil matrix hydrodynamically disperse into the field-saturated fracture network that contains meteoric recharge water. A soil moisture deficit in discharge season produces a vadose zone of widened fractures that via capillarity enhances the diffusion of contaminants into the soil matrix. These enlarged connecting conduits laterally channel the excess infiltration from the recharge season and diffused contaminants to local lowlands and incised streams that truncate the unweathered till. The current vadose and phreatic zone flow study will be used in numeric simulations that will delineate the areal extend and temporal duration of these seepage faces and the time frame of possible surfaces water contamination.

Frederick, W.T.; Grasso, T.X. Jr. (Dames and Moore, West Valley, NY (United States))

1993-03-01

244

Moderator Chemistry Program  

SciTech Connect

Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

1990-11-01

245

Moderator Chemistry Program  

SciTech Connect

Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

1990-11-01

246

Service-Learning in Introductory Chemistry: Supplementing Chemistry Curriculum in Elementary Schools  

Microsoft Academic Search

The pedagogy of service-learning is becoming an accepted method of connecting college classrooms to the community. A service-learning course component has been successfully incorporated into the second quarter of Introductory Chemistry (Chem 120) at Kalamazoo College. Students in Chem 120 design inquiry-based laboratory experiments related to course material for students in grades K 6. The Chem 120 students then conduct

Joan M. Esson; Regina Stevens-Truss; Anne Thomas

2005-01-01

247

The Chemistry Resource Center  

NSDL National Science Digital Library

Maintained by the British Columbia Institute of Technology Chemistry Department, The Chemistry Resource Center Web site bills itself as "on-line multi-media tutor to direct students to find textbook references, interesting WWW links and to guide them to solve Chemistry problems." Among the many activities on the site, probably the most interesting is the "How well do you know your Periodic Table?" link, which helps to teach students the basics of the elements and the periodic table through a unique interactive online exercise.

2000-01-01

248

Green Chemistry Teaching Resources  

NSDL National Science Digital Library

The American Chemical Society (ACS) has created these excellent resources via the Green Chemistry Institute and the ACS Education Division. The goal of these materials is "to increase awareness and understanding of Green Chemistry principles, alternatives, practices, and benefits within traditional educational institutions and among practicing scientists." In the Online Resources section, visitors will find downloadable pocket guides to basic green chemistry principles, "Greener Education Materials for Chemists" from the University of Oregon, and more. Perhaps the best section of the site is Activities and Experiments, where visitors can look over activities like "Gassing Up Without Air Pollution" and "Cleaning Up With Atom Economy."

2012-10-26

249

Green Chemistry Teaching Resources  

NSDL National Science Digital Library

The American Chemical Society (ACS) has created these excellent resources via the Green Chemistry Institute and the ACS Education Division. The goal of these materials is "to increase awareness and understanding of Green Chemistry principles, alternatives, practices, and benefits within traditional educational institutions and among practicing scientists." In the Online Resources section, visitors will find downloadable pocket guides to basic green chemistry principles, "Greener Education Materials for Chemists" from the University of Oregon, and more. Perhaps the best section of the site is Activities and Experiments, where visitors can look over activities like "Gassing Up Without Air Pollution" and "Cleaning Up With Atom Economy."

250

Wizardry and Chemistry  

NSDL National Science Digital Library

Students learn how common pop culture references (Harry Potter books) can relate to chemistry. While making and demonstrating their own low-intensity sparklers (muggle-versions of magic wands), students learn and come to appreciate the chemistry involved (reaction rates, Gibb's free energy, process chemistry and metallurgy). The fun part is that all wands are personalized and depend on how well students conduct the lab. Students end the activity with a class duelâa face-off between wands of two different chemical compositions. This lab serves as a fun, engaging review for stoichiometry, thermodynamics, redox and kinetics, as well as advanced placement course review.

University Of Houston

251

Microscale Gas Chemistry  

NSDL National Science Digital Library

Created by Professor Bruce M. Mattson, PhD, of Creighton University's Department of Chemistry, the Microscale Gas Chemistry Website "provides instructions for the generation of gases on a microscale level along with instructions for chemical demonstrations and student laboratory experiments with the gases." The no-frills site, designed for high school and university chemistry teachers, contains clear and careful instructions for experiments with carbon dioxide, hydrogen, oxygen and nitrogen, nitrogen oxides, ammonia, ethene, chlorine, carbon monoxide, and more. An introduction offers two low-tech methods for gas generation. Data pages for relevant gases are linked to each experiment.

252

Materials Chemistry at SFU  

NSDL National Science Digital Library

The Materials Science group at Simon Fraser University (SFU) developed this website to address the group's primary research interests in material synthesis, molecular, electronics, and photonics. Visitors will find explanations covering sixteen research topics including chemical sensors, lithography, non-linear optics, and supramolecular chemistry. Under each topic heading, users will find links discussing the faculties' current goals, recent publications, and patents. The site also features links to the Pacific Centre for Advanced Materials and Microstructures; a collaborative effort between the Materials Science group at SFU and the physics and chemistry departments at the University of British Columbia. Anyone searching for the latest investigations in materials chemistry will find this website very informative.

253

CCR Connections: Related Links  

Cancer.gov

CCR Connections Skip to Main Content Home This Issue Features Delving More Than Skin Deep Seeing the Unexpected Deconstructing Health Disparities News New Web-Based Tools Make Systems Pharmacology More Accessible Using Data from the NCI-60 New Targeted

254

CCR Connections: Past Issues  

Cancer.gov

CCR Connections Skip to Main Content Home This Issue Features Delving More Than Skin Deep Seeing the Unexpected Deconstructing Health Disparities News New Web-Based Tools Make Systems Pharmacology More Accessible Using Data from the NCI-60 New Targeted

255

Reassessment of the Bahamas Fracture Zone  

SciTech Connect

The Bahamas Fracture Zone trends northwestward across south Florida and the Western Florida shelf, and it appears to connect with the Gilbertown-Pickens-Pollard portion of the circum-Gulf of Mexico fault system. Along the fracture zone's trend, seismic reflection data reveal normal displacement in the Late Jurassic section of a kilometer, on a down-to-the-west fault, 9 km east of the east end of Destin dome in the Apalachicola basin. This fault was active in Late Jurassic and Early Cretaceous time during the gulf spreading event. The Middle Jurassic Louann Salt thins abruptly to the east across this fault. Toward the southeast, where the fracture zone crosses the Florida peninsula, gravity data have previously been interpreted to indicate coincidence of the Bahamas Fracture Zone with a hinge zone attended by relief on the Mohorovicic discontinuity. This interpretation is an artifact resulting from the use of erroneously low densities for the sedimentary fill of the South Florida basin. The inclusion of a nonexistent negative component for the basin's sedimentary fill necessitated the inclusion of an equally nonexistent positive contribution from relief on the Moho in order to match the observed anomaly. Although northwestward-trending faults do cross south Florida and the Western Florida shelf, the role of the Bahamas Fracture Zone as a boundary between continental and transitional or oceanic crust is insupportable.

Ball, M.M. (Geological Survey, Evergreen, CO (United States))

1991-03-01

256

Flexible connection apparatus  

SciTech Connect

A flexible connection apparatus is disclosed for accommodating relative movement between a compliant offshore structure and the sea floor. The compliant offshore structure supports a fluid-carrying system which conveys fluids between the sea floor and the structure. The fluid-carrying system includes a riser and a helical flowline. The lower end of the riser is connected to the sea floor. The first end of the helical flowline is connected to the upper end of the riser and the second end of the helical flowline is connected to the structure. As the compliant offshore structure is displaced from its vertical equilibrium position due to loading forces induced by wind, waves, and ocean currents, the helical flowline elastically flexes through torsional deflection to accommodate such movement. In a preferred embodiment of the apparatus, a wellhead is connected between the riser and the helical flowline such that the centerline of the helical flowline is substantially vertical. In yet another embodiment of the apparatus, a bending flowline is connected between a wellhead and the structure with its centerline being substantially horizontal to accommodate movement of the structure through bending deflection rather than by torsional deflection.

Barth, J.R.; Fowler, J.R.; Hitchcock, W.A.; Miller, J.E.

1984-06-26

257

Complex plume dynamics in the transition zone underneath the Hawaii hotspot: seismic imaging results  

NASA Astrophysics Data System (ADS)

In recent years, progress has been made in seismology to constrain the depth variations of the transition zone discontinuities, e.g. 410 km and 660 km discontinuities, which can be used to constrain the local temperature and chemistry profiles, and hence to infer the existences and morphology of mantle plumes. Taking advantage of the abundance of natural earthquake sources in western Pacific subduction zones and the many seismograph stations in the Americas, we used a generalized Radon transform (GRT), a high resolution inverse-scattering technique, of SS precursors to form 3-D images of the transition zone structures of a 30 degree by 40 degree area underneath Hawaii and the Hawaii-Emperor seamount chain. Rather than a simple mushroom-shape plume, our seismic images suggest complex plume dynamics interacting with the transition zone phase transitions, especially at the 660’ discontinuity. A conspicuous uplift of the 660 discontinuity in a region of 800km in diameter is observed to the west of Hawaii. No correspondent localized depression of the 410 discontinuity is found. This lack of correlation between and differences in lateral length scale of the topographies of the 410 and 660 km discontinuities are consistent with many geodynamical modeling results, in which a deep-mantle plume impinging on the transition zone, creating a pond of hot material underneath endothermic phase change at 660 km depth, and with secondary plumes connecting to the present-day hotspot at Earth’s surface. This more complex plume dynamics suggests that the complicated mass transport process across the transition zone should be taken into account when we try to link the geochemical observations of Hawaiian basalt geochemistry at the Earth’s surface to deep mantle domains. In addition to clear signals at 410km, 520km and 660km depth, the data also reveals rich structures near 350km depth and between 800 - 1000km depth, which may be regional, laterally intermittent scatter interfaces. This may suggest the influence of water or minor chemical constitutes and calls for interpretations from geodynamics and mineral physics.

Cao, Q.; van der Hilst, R. D.; de Hoop, M. V.; Shim, S.

2010-12-01

258

Uncertainty in integrated coastal zone management  

Microsoft Academic Search

Uncertainty plays a major role in Integrated Coastal Zone Management (ICZM). A large part of this uncertainty is connected\\u000a to our lack of knowledge of the integrated functioning of the coastal system and to the increasing need to act in a pro-active\\u000a way. Increasingly, coastal managers are forced to take decisions based on information which is surrounded by uncertainties.\\u000a Different

Henriëtte S. Otter

2000-01-01

259

Integrating Symmetry in Stereochemical Analysis in Introductory Organic Chemistry  

ERIC Educational Resources Information Center

|We report a comparative study using "knowledge space theory" (KAT) to assess the impact of a hands-on laboratory exercise that used molecular model kits to emphasize the connections between a plane of symmetry, Charity, and isomerism in an introductory organic chemistry course. The experimental design compared three groups of students--two that…

Taagepera, Mare; Arasasingham, Ramesh D.; King, Susan; Potter, Frank; Martorell, Ingrid; Ford, David; Wu, Jason; Kearney, Aaron M.

2011-01-01

260

Integrating Webinar and Blogging Technologies into Chemistry Seminar  

ERIC Educational Resources Information Center

|We report successfully integrating webinar and blogging into an undergraduate chemistry and biochemistry seminar course. Commercial collaboration software linked speaker-operated slides with two-way voice and video effectively connecting the audience and presenter from different states. Student responses to the technology and seminar content were…

Hamstra, Dan; Kemsley, Jyllian N.; Murray, Desmond H.; Randall, David W.

2011-01-01

261

Sequencing General Chemistry  

NSDL National Science Digital Library

The material in the authors' general chemistry curriculum has been rearranged into a sequence thought to be more logical to students than the traditional sequence. This fresh approach does not radically change course content but rather produces a systemat

Yoblinski, B. J.

2003-03-01

262

Chemistry, Population, Resources.  

National Technical Information Service (NTIS)

Chemistry plays a central role in the global development of the world's human population and their resources. Its effect is exercised primarily through (1) the production of food, (2) public health, and (3) medical practice and drugs. These factors togeth...

M. Calvin

1977-01-01

263

Chemistry with a Peel.  

ERIC Educational Resources Information Center

Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)

Borer, Londa; Larsen, Eric

1997-01-01

264

Virtual Chemistry Experiments  

NSDL National Science Digital Library

Chemistry applets simulate various experiments, apparatus, and chemical processes. The display and operation of an applet can be controlled by the user through the PARAM options in the APPLET tag and through JavaScript commands.

Blauch, David N.

265

Chemistry with a Peel.  

ERIC Educational Resources Information Center

|Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)|

Borer, Londa; Larsen, Eric

1997-01-01

266

Chemistry Laboratory Safety Check  

ERIC Educational Resources Information Center

|An accident prevention/safety check list for chemistry laboratories is printed. Included are checks of equipment, facilities, storage and handling of chemicals, laboratory procedures, instruction procedures, and items to be excluded from chemical laboratories. (SL)|

Patnoe, Richard L.

1976-01-01

267

Opportunities in Chemistry.  

National Technical Information Service (NTIS)

Chemistry is a central science that responds to societal needs. It is critical in man's attempts to discover new processes, tap new sources of energy, develop new materials, feed the world's population, improve health and conquer disease, monitor and prot...

1985-01-01

268

Wet Chemistry Instrument Prototype.  

National Technical Information Service (NTIS)

A wet chemistry instrument prototype for detecting amino acids in planetary soil samples was developed. The importance of amino acids and their condensation products to the development of life forms is explained. The characteristics of the instrument and ...

1974-01-01

269

General Chemistry Multimedia Problems  

NSDL National Science Digital Library

General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.

270

Chemistry and Detective Fiction.  

ERIC Educational Resources Information Center

Describes an interdisciplinary program consisting of two courses. The first course deals with the chemistry of drugs and poisons; the second course focuses on fictional works in which these drugs and poisons are central to the plots. (SK)

Labianca, Dominick A.; Reeves, William J.

1981-01-01

271

Kane Fracture Zone  

Microsoft Academic Search

The Kane Fracture Zone probably is better covered by geophysical survey data, acquired both by design and incidentally, than\\u000a any other fracture zone in the North Atlantic Ocean. We have used this data to map the basement morphology of the fracture\\u000a zone and the adjacent crust for nearly 5700 km, from near Cape Hatteras to the middle of the Mesozoic

Brian E. Tucholke; Hans Schouten

1988-01-01

272

Polygonal Fresnel zone plates  

NASA Astrophysics Data System (ADS)

The performance of Fresnel zone plates having a polygonal boundary between zones has been studied. The contribution of the complex amplitude of each zone is calculated analytically and numerically solved. The case of a continuous phase plate is considered as the limit case in performance for each polygonal shape. This performance is compared with respect to the circular case. Also four different methods to define a polygonal FZP having discrete phase shift are analyzed and compared.

Alda, Javier; González, Francisco Javier

2009-08-01

273

Marginal Zone Lymphomas  

Microsoft Academic Search

\\u000a \\u000a Marginal zone lymphoma (MZL) encompasses a heterogeneous group of small B-cell lymphomas, characterized by a predominance of tumor cells with a\\u000a phenotype, homing pattern, and occasionally the appearance of the nonneoplastic marginal zone B cells that surround germinal centers and populate the white pulp of the spleen. Covered in this chapter are extranodal marginal\\u000a zone lymphoma of mucosa-associated lymphoid tissue

Rachel L. Sargent

274

Organic Chemistry Forum  

NSDL National Science Digital Library

ChemWeb's Organic Chemistry Forum bills itself as a "free online club for the organic chemistry community." Users will need to complete a simple online form to obtain membership and access the site. One highlight of this site is free full-text access to Tetrahedron Letters. This rapid publication journal appears weekly. Along with free access to Beilstein Abstracts, the site includes jobs, a conference diary, news, discussion groups, and more.

2005-01-01

275

UCLA: Organic Chemistry Tutorials  

NSDL National Science Digital Library

Steven Hardinger at the Department of Chemistry and Biochemistry at UCLA created these tutorials to assist students with the difficult concepts presented in introductory organic chemistry. Students can find tutorials dealing with acids and bases, carbocations, Lewis dot structures, and more. Within each tutorial, users can find links to a dictionary that adequately explain the unfamiliar terminology. The tutorials include example problems and exercises to challenge users.

Hardinger, Steven

276

Nicotine Smoke Chemistry  

NSDL National Science Digital Library

The featured molecules this month come from the paper Using "Basic Principles" To Understand Complex Science: Nicotine Smoke Chemistry and Literature Analogies by Jeffrey Seeman detailing some of the complexities involved in the volatilization of two alkaloids, nicotine and cocaine. Students could be asked to identify how chemistry is involved in the various steps described in the paper, and most beginning students will be surprised to learn just how complex a process the volatilization of a molecule such as nicotine is.

277

The chemistry of krypton  

Microsoft Academic Search

Krypton is the only noble gas other than xenon to give rise to isolable compounds in macroscopic amounts, although the chemistry of krypton is presently limited to the +2 oxidation state. The strong oxidant-fluorinator properties and thermal instabilities of krypton(II) compounds have posed considerable challenges to determining the extent to which the chemistries of krypton(II) and xenon(II) are analogous. Krypton(II)

John F. Lehmann; Hélène P. A. Mercier; Gary J. Schrobilgen

2002-01-01

278

General Chemistry I  

NSDL National Science Digital Library

From Dr. Michael Bleber of Florida State University's Department of Chemistry, this page contains a virtual guide for a first semester undergraduate course in general chemistry. The site features lecture notes, practice homework, practice exams, homework assignments, useful tables, and a FAQ. The variety and depth of materials at this site make it useful for educators looking for teaching aids, as well as students in search of additional course information.

279

Darwinian evolution and chemistry  

Microsoft Academic Search

Some significant results are collected with a view to ascertain whether a Darwinian chemical evolution is at work in chemistry\\u000a and, if so, to define its specific characters. To this aim prebiotic chemistry, homochirality; chemical reactions and emergence\\u000a of new properties are considered. The Darwinian process of mutation by chance, selection and replication appears to translate\\u000a into chemical exploration of

Gian Paolo Chiusoli

2009-01-01

280

IMMUNE ZONES IN LEPROSY  

PubMed Central

Leprosy affects mainly those areas of skin which have a relatively lower temperature and are more exposed to trauma. Certain zones like scalp, palms and soles, genitalia, groins, axillae, eyelids, transverse band of skin over lumboscaral area, midline of back and perineum have been described to be immune to the development of lesions in leprosy. But clinical, histological and bacteriological evidence of involvement of these so called immune zones though infrequent have been documented. Hence, these immune zones should be termed as relatively immune, rather than absolutely immune zones of leprosy.

Rajashekar, T S; Singh, Gurcharan; Naik, L Chandra

2009-01-01

281

Underwater connection apparatus  

SciTech Connect

This patent describes, in a subsea system for the production of oil or gas from subsurface formations or the injection of liquids or gases into subsurface formations, a subsea system for landing and securing ocean floor flowlines to the system, comprising a flowline receiving structure having two slide plates which are space apart, a first circular hole in each side plate on a first centerline, and a circular projection on each side plate about the first centerline; a flowline end connection suitable for attaching directly to the flowlines before the flowlines are lowered into the water. It includes a first spring loaded pin on each side of the flowline end connection on a second centerline with the second centerline being at right angles to the centerline of the flowlines, a funnel shaped means with a cylindrical stop surface at the bottom of the funnel shaped area on each side of the flowline end connection with the cylindrical stop surface about the second centerline, and circular fixed pin members on each side of the flowline end connection for attachment of pulling tool means also about the second centerline; and a pulling tool means with a guidance nose means including attachment means for engaging the circular fixed pin members and a connection to a wire rope or the such like, a receptacle means for receiving and positioning the guidance nose means, and a wire rope means which can be tensioned to pull the guidance nose means toward and into the receptacle means.

Baugh, B.F.

1987-02-10

282

Dynamic covalent chemistry.  

PubMed

Dynamic covalent chemistry relates to chemical reactions carried out reversibly under conditions of equilibrium control. The reversible nature of the reactions introduces the prospects of "error checking" and "proof-reading" into synthetic processes where dynamic covalent chemistry operates. Since the formation of products occurs under thermodynamic control, product distributions depend only on the relative stabilities of the final products. In kinetically controlled reactions, however, it is the free energy differences between the transition states leading to the products that determines their relative proportions. Supramolecular chemistry has had a huge impact on synthesis at two levels: one is noncovalent synthesis, or strict self-assembly, and the other is supramolecular assistance to molecular synthesis, also referred to as self-assembly followed by covalent modification. Noncovalent synthesis has given us access to finite supermolecules and infinite supramolecular arrays. Supramolecular assistance to covalent synthesis has been exploited in the construction of more-complex systems, such as interlocked molecular compounds (for example, catenanes and rotaxanes) as well as container molecules (molecular capsules). The appealing prospect of also synthesizing these types of compounds with complex molecular architectures using reversible covalent bond forming chemistry has led to the development of dynamic covalent chemistry. Historically, dynamic covalent chemistry has played a central role in the development of conformational analysis by opening up the possibility to be able to equilibrate configurational isomers, sometimes with base (for example, esters) and sometimes with acid (for example, acetals). These stereochemical "balancing acts" revealed another major advantage that dynamic covalent chemistry offers the chemist, which is not so easily accessible in the kinetically controlled regime: the ability to re-adjust the product distribution of a reaction, even once the initial products have been formed, by changing the reaction's environment (for example, concentration, temperature, presence or absence of a template). This highly transparent, yet tremendously subtle, characteristic of dynamic covalent chemistry has led to key discoveries in polymer chemistry. In this review, some recent examples where dynamic covalent chemistry has been demonstrated are shown to emphasise the basic concepts of this area of science. PMID:12491278

Rowan, Stuart J; Cantrill, Stuart J; Cousins, Graham R L; Sanders, Jeremy K M; Stoddart, J Fraser

2002-03-15

283

Algebraic connectivity and graph robustness.  

SciTech Connect

Recent papers have used Fiedler's definition of algebraic connectivity to show that network robustness, as measured by node-connectivity and edge-connectivity, can be increased by increasing the algebraic connectivity of the network. By the definition of algebraic connectivity, the second smallest eigenvalue of the graph Laplacian is a lower bound on the node-connectivity. In this paper we show that for circular random lattice graphs and mesh graphs algebraic connectivity is a conservative lower bound, and that increases in algebraic connectivity actually correspond to a decrease in node-connectivity. This means that the networks are actually less robust with respect to node-connectivity as the algebraic connectivity increases. However, an increase in algebraic connectivity seems to correlate well with a decrease in the characteristic path length of these networks - which would result in quicker communication through the network. Applications of these results are then discussed for perimeter security.

Feddema, John Todd; Byrne, Raymond Harry; Abdallah, Chaouki T. (University of New Mexico)

2009-07-01

284

Sun-Earth Connection  

NSDL National Science Digital Library

One of three divisions within the Office of Space Science at NASA, the Sun-Earth Connection has the primary goal of understanding the Sun, Heliosphere, and planetary environments as a single connected system. The Web site offers visitors information on space science missions including the Living with a Star and Solar Terrestrial Probes mission. Meeting notes and official reports can be viewed online, including the Sun Earth Connection 2002 Strategic Plan. Other items of interest include information on the science and technology behind the missions, education and news links, and more. One highlight of the site is the image gallery that includes some of the most incredible photos and illustrations of the sun that are available online.

285

Inert electrode connection  

DOEpatents

An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000--20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1,200--1,500 C. 5 figs.

Weyand, J.D.; Woods, R.W.; DeYoung, D.H.; Ray, S.P.

1985-02-19

286

Inert electrode connection  

DOEpatents

An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000-20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1200.degree.-1500.degree. C.

Weyand, John D. (Greensburg, PA); Woods, Robert W. (New Kensington, PA); DeYoung, David H. (Plum Boro, PA); Ray, Siba P. (Plum Boro, PA)

1985-01-01

287

Vertical Variability in Saturated Zone Hydrochemistry Near Yucca Mountain, Nevada  

SciTech Connect

The differences in the saturated zone hydrochemistry with depth at borehole NC-EWDP-22PC reflect the addition of recharge along Fortymile Wash. The differences in water chemistry with depth at borehole NC-EWDP-19PB appear to indicate that other processes are involved. Water from the lower part of NC-EWDP-19PB possesses chemical characteristics that clearly indicate that it has undergone cation exchange that resulted in the removal of calcium and magnesium and the addition of sodium. This water is very similar to water from the Western Yucca Mountain facies that has previously been thought to flow west of NC-EWDP-19PB. Water from the lower zone in NC-EWDP-19PB also could represent water from the Eastern Yucca Mountain facies that has moved through clay-bearing or zeolitized aquifer material resulting in the altered chemistry. Water chemistry from the upper part of the saturated zone at NC-EWDP-19PB, both zones at NC-EWDP-22PC, and wells in the Fortymile Wash facies appears to be the result of recharge through the alluvium south of Yucca Mountain and within the Fortymile Wash channel.

G. Patterson; P. Striffler

2007-02-17

288

Single zone control systems  

SciTech Connect

The number of old single zone systems which are operating today is quite high, providing numerous opportunities for retrofit to improve both space conditions and energy consumption characteristics. This report will cover the fundamentals of system controls applied to the single zone unit.

Kapka, L.A.

1987-01-01

289

The Shadow Zone  

NSDL National Science Digital Library

This is a demonstration of the Core Shadow Zone of the Earth. Using a clear or translucent half-sphere held in front of a light source, the refracting properties of the core and how it generates the shadow zone on the surface are illustrated.

Barker, Jeffrey

290

Subduction of fracture zones  

NASA Astrophysics Data System (ADS)

Since Wilson proposed in 1965 the existence of a new class of faults on the ocean floor, namely transform faults, the geodynamic effects and importance of fracture zone subduction is still little studied. It is known that oceanic plates are characterized by numerous fracture zones, and some of them have the potential to transport into subduction zones large volumes of water-rich serpentinite, providing a fertile water source for magma generated in subduction-related arc volcanoes. In most previous geodynamic studies, subducting plates are considered to be homogeneous, and there is no clear indication how the subduction of a fracture zone influences the melting pattern in the mantle wedge and the slab-derived fluids distribution in the subarc mantle. Here we show that subduction of serpentinized fracture zones plays a significant role in distribution of melt and fluids in the mantle wedge above the slab. Using high-resolution tree-dimensional coupled petrological-termomechanical simulations of subduction, we show that fluids, including melts and water, vary dramatically in the region where a serpentinized fracture zone enters into subduction. Our models show that substantial hydration and partial melting tend to concentrate where fracture zones are being subducted, creating favorable conditions for partially molten hydrous plumes to develop. These results are consistent with the along-arc variability in magma source compositions and processes in several regions, as the Aleutian Arc, the Cascades, the Southern Mexican Volcanic Arc, and the Andean Southern Volcanic Zone.

Constantin Manea, Vlad; Gerya, Taras; Manea, Marina; Zhu, Guizhi; Leeman, William

2013-04-01

291

Coastal zone management  

Microsoft Academic Search

In response to the problems of pollution, overdevelopment, shore erosion and population expansion along America's seashores, Congress approved the Coastal Zone Management Act of 1972. It gave 30 coastal states the responsibility for developing plans to protect and promote the 20,000 miles of United States coastline. Coastal Zone Management represents an effort to help the states and cities save coastal

Castello

1976-01-01

292

Subsea wellhead connection assembly  

SciTech Connect

A wellhead connector assembly for use on undersea template platform where a plurality of wellheads are connected to a center work enclosure hull having a plurality of penetration connectors projecting from its sidewall. The present assembly has a connector for fitting on the wellhead, and a laterally movable connector for coupling with a penetration connector. A vertical actuation rod pivots a bell crank linked to the connector to cause lateral movement thereof. A loop of pipe connects the wellhead to the laterally movable connector and biases it to a neutral position.

Miller, H. W.

1985-05-21

293

Soil Solution Chemistry and Element Fluxes in Three European Heathlands and Their Responses to Warming and Drought  

Microsoft Academic Search

Soil water chemistry and element budgets were studied at three northwestern European Calluna vulgaris heathland sites in Denmark (DK), The Netherlands (NL), and Wales (UK). Responses to experimental nighttime warming and early summer drought were followed during a two-year period. Soil solution chemistry measured below the organic soil layer and below the rooting zone and water fluxes estimated with hydrological

Inger K. Schmidt; Albert Tietema; Dylan Williams; Per Gundersen; Claus Beier; Bridget A. Emmett; Marc Estiarte

2004-01-01

294

Theme-Based Bidisciplinary Chemistry Laboratory Modules  

NASA Astrophysics Data System (ADS)

A thematic approach to each of the two introductory chemistry laboratory sequences, general and organic chemistry, not only provides an element of cohesion but also stresses the role that chemistry plays as the "central science" and emphasizes the intimate link between chemistry and other science disciplines. Thus, in general chemistry the rubric "Environmental Chemistry" affords connections to the geosciences, whereas experiments on the topic of "Plant Assays" bridge organic chemistry and biology. By establishing links with other science departments, the theme-based laboratory experiments will satisfy the following multidisciplinary criteria: (i) to demonstrate the general applicability of core methodologies to the sciences, (ii) to help students relate concepts to a broader multidisciplinary context, (iii) to foster an attitude of both independence and cooperation that can transcend the teaching laboratory to the research arena, and (iv) to promote greater cooperation and interaction between the science departments. Fundamentally, this approach has the potential to impact the chemistry curriculum significantly by including student decision-making in the experimental process. Furthermore, the incorporation of GC-MS, a powerful tool for separation and identification as well as a state-of-the-art analytical technique, in the modules will enhance the introductory general and organic chemistry laboratory sequences by making them more instrument-intensive and by providing a reliable and reproducible means of obtaining quantitative analyses. Each multifaceted module has been designed to meet the following criteria: (i) a synthetic protocol including full spectral characterization of products, (ii) quantitative and statistical analyses of data, and (iii) construction of a database of results. The database will provide several concrete functions. It will foster the idea that science is a continuous incremental process building on the results of earlier experimentalists, it will reinforce an understanding of the scientific method by allowing students to propose testable hypotheses based on previous work, and it will generate a large body of quantitative data that can be used to illustrate the fundamentals of data analysis, including statistical measures of uncertainty. We have already developed several "Environmental Chemistry" modules for general chemistry, including monitoring for orthophosphate and nitrate concentrations in water using colorimetric analyses and assaying for gasoline contamination in water and soil samples using GC-MS. Another module dealing with herbicide residues in soil is still being explored. However, we purposefully choose here to emphasize the two modules that are under development for implementation in the organic chemistry laboratory sequence. The first "Plant Assay" project focuses on fatty acid methyl esters (FAMEs) and involves three discrete phases: (i) synthesis and characterization of FAME standards, (ii) isolation of the fatty acids (as FAMEs) from a variety of different plant leaves that will be collected by BIO 110 students on field trips, and (iii) qualitative and quantitative analysis of the plant leaf extract for whole-leaf lipid composition. Acid-catalyzed Fischer esterification of carboxylic acids in methanol is a standard methodology for the preparation of methyl esters. A textbook procedure (1) for the synthesis of ethyl laurate has been employed, with good success, to prepare eight FAMEs in yields of ca. 70%. Conversion of leaf phospholipids to FAMEs proceeds readily via a transesterification reaction. Treatment of the whole leaf in a methanolic HCl solution for an hour at 80 °C (2) is sufficient after extraction in hexane to provide a suitable sample for GC-MS analysis. Preliminary results obtained with an HP GCD system indicate that GC-MS will afford highly reliable quantitative data on FAME lipid composition. Possible extensions of the project include using boron trifluoride in methanol to effect transesterification (3) and examini

Leber, Phyllis A.; Szczerbicki, Sandra K.

1996-12-01

295

Technetium Chemistry in HLW  

SciTech Connect

Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry.

Hess, Nancy J.; Felmy, Andrew R.; Rosso, Kevin M.; Xia Yuanxian

2005-06-06

296

Residue chemistry guidelines.  

PubMed

Residue chemistry guidelines are designed to determine what the potential residues in food are and how much may be present as a result of pesticide application, so that a tolerance level may be established. Some requirements are established to assist in the enforcement of tolerances by the USDA, FDA, and the states. I realize I have given you a quick overview of the residue chemistry requirements. There are many documents which are available if you should require more information, such as the Subdivision O Residue Chemistry Guidelines, Standard Evaluation Procedures (which are used by reviewers when evaluating the studies), the Data Reporting Guidelines (which provide guidance on preparing final reports), and the Technical Guidance from Phase III of Reregistration. We have also released various papers on studies when additional guidance is required. Most of these documents are available from NTIS. I hope you will consider this information when auditing residue chemistry studies. As I see the efforts that you, the QA professionals, have made to educate yourselves on residue chemistry studies through programs such as this meeting, I have a little more confidence in answering the question "Do you trust them?" with a "Yes." Thank you. PMID:8156199

Olinger, C L; Schmitt, R D; Zager, E

297

ZoneAlarm 5.5.094.000  

NSDL National Science Digital Library

This latest application from ZoneLabs is intended to assist users who wish to protect their DSL- or cable-connected personal computer from marauding hackers. The program includes four interlocking security services, including a firewall and Internet lock, and an application control. The Interlock is particularly handy, as it effectively blocks Internet traffic while your computer is unattended. This version of ZoneAlarm is compatible with Windows 98 or newer.

298

Supergiant Complexes of Solar Activity and Convection Zone  

Microsoft Academic Search

The global distribution of solar surface activity (active regions) is apparently connected with processes in the convection\\u000a zone. The large-scale magnetic structures above the tachocline could in a pronounced way be observable in the surface magnetic\\u000a field. To get the information regarding large-scale magnetic formations in the convection zone, a set of solar synoptic charts\\u000a (Mount Wilson 1998?–?2004, Fe?i, 525.02 nm)

O. V. Arkhypov; O. V. Antonov; M. L. Khodachenko

2011-01-01

299

Making News Connections.  

ERIC Educational Resources Information Center

Describes how one teacher uses news articles to teach connections between the present-day real world and the books that her students read. Notes that her intent is to help readers transfer concepts from one domain (their reading) to another (real life). Offers the example of how this was done with the book "The Giver" by Lois Lowry. (SR)

Swiderek, Bobbi

1998-01-01

300

Making the Connection  

ERIC Educational Resources Information Center

|Enrollment marketing is not just about enrollment; it is about creating relationships and serving one's community or target audience for many years. In this article, the author states that the first step in building such relationships is making a connection, and that is what effective marketing is all about. Administrators, teachers and critical…

Perna, Mark C.

2006-01-01

301

Connect the Dots (polygons)  

NSDL National Science Digital Library

The purpose of this activity is to familiarize the student with the basic shapes and types of polygons. Using an activity that most have done and seen in their childhood like "connect the dots", it will be easier for the student to recognize and memorize the shapes and types of polygons.

2010-01-01

302

Technology and Internet Connections.  

ERIC Educational Resources Information Center

Suggests that teachers can use computer software and Internet connections to enhance curriculum and capitalize student's natural interest in sports and sports figures. Provides a list of activities that students can do in relation to the Olympic games and gives information on how technology can assist in such activities. Appropriate Internet…

Allen, Denise; Lindroth, Linda

1996-01-01

303

The Connection Machine  

Microsoft Academic Search

This book describes what history may judge to be the second stage in the evolution of digital computers. Up to now, all computers have had basically the same architecture: one or a few large memory banks. Challenging that conception, the Connection Machine links together thousands or millions of extremely small processors and memories. From each moment to the next, the

W. Daniel Hillis

1985-01-01

304

Connecting to professional knowledge  

Microsoft Academic Search

Studies of students’ educational outcomes tend to be based on rather simple input–output models. The aim of this article is to demonstrate that more informed theoretical perspectives are appropriate to analyses of quantitative data on professional learning processes. It is suggested that ‘connection to knowledge’ and ‘wanting structure’ are appropriate concepts in this respect. Results from a study of college

2007-01-01

305

The Game Port Connection.  

ERIC Educational Resources Information Center

Provides ideas for using the same port connection of personal computers to interface with laboratory instruments. Contains specific instructions on how to build transducers. Includes plans and diagrams for thermistors and light meters as well as computer programs for displaying instrument readings on monitors. (TW)

Sievers, Dennis

1986-01-01

306

Our Cosmic Connection  

ERIC Educational Resources Information Center

|To help students understand the connection that Earth and the solar system have with the cosmic cycles of stellar evolution, and to give students an appreciation of the beauty and elegance of celestial phenomena, the Chandra X-Ray Center (CXC) educational website contains a stellar evolution module that is available free to teachers. In this…

Young, Donna L.

2005-01-01

307

Connecting assembly and method  

Microsoft Academic Search

Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The

Wardlaw

1980-01-01

308

Long-Distance Connection  

ERIC Educational Resources Information Center

Transient populations, cultural diversity, language barriers, competing loyalties, and geographic separation are just some of the challenges international schools face in communicating and connecting with their alumni. And these issues are not going to get any easier as the sector grows. Communicating effectively with large, diverse groups of…

Clift, Kate

2010-01-01

309

Connecting Electricity and Magnetism  

NSDL National Science Digital Library

As discussed at the beginning of the book, there is an intimate connection between electricity and magnetism, which will be further addressed in this chapter as well. We'll end up with a scientific model for what magnetism is, what makes something a permanent magnet, and why magnets attract some metals and not others.

Robertson, William C.

2005-01-01

310

Subsea wellhead connection assembly  

Microsoft Academic Search

A wellhead connector assembly for use on undersea template platform where a plurality of wellheads are connected to a center work enclosure hull having a plurality of penetration connectors projecting from its sidewall. The present assembly has a connector for fitting on the wellhead, and a laterally movable connector for coupling with a penetration connector. A vertical actuation rod pivots

1985-01-01

311

The CORALS Connection  

ERIC Educational Resources Information Center

|The Ocean, Reefs, Aquariums, Literacy, and Stewardship (CORALS) research program helps students connect global environmental issues to local concerns and personal choices. During the 18-week program, students strengthen their understanding of coral reef decline through a classroom aquarium activity, communicate with science experts, and create…

Plankis, Brian; Klein, Carolyn

2010-01-01

312

Long-Distance Connection  

ERIC Educational Resources Information Center

|Transient populations, cultural diversity, language barriers, competing loyalties, and geographic separation are just some of the challenges international schools face in communicating and connecting with their alumni. And these issues are not going to get any easier as the sector grows. Communicating effectively with large, diverse groups of…

Clift, Kate

2010-01-01

313

CONNECTING WITH WORK  

Microsoft Academic Search

This study considers to what extent immigrants' social networks have acted as important resources that have helped them to connect with employment opportunities during their entire occupational careers in Finland. Adopting a comprehensive job-acquisition model, it offers a detailed investigation into how job information that led to employment is acquired and transmitted, how the jobs themselves are applied for, and

Akhlaq Ahmad

2011-01-01

314

Parabolically connected subgroups  

SciTech Connect

All reductive spherical subgroups of the group SL(n) are found for which the intersections with every parabolic subgroup of SL(n) are connected. This condition guarantees that open equivariant embeddings of the corresponding homogeneous spaces into Moishezon spaces are algebraic. Bibliography: 6 titles.

Netai, Igor V [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

2011-08-31

315

Solderless Wrapped Connection  

Microsoft Academic Search

The solderless wrapped connection is introduced. The terms automatic factory and assembly are defined. Electronic industry growth over the last 30 years is discussed and its expansion during the next 10 years is predicted at 300 percent. The importance of modular building blocks and modular terminal spacing, in the program of standardization for automation, is emphasized. The solid-wire solderless wrapped

R. Mallina

1956-01-01

316

"Write" Reading Connection.  

ERIC Educational Resources Information Center

|Proposes a model which connects the acts of reading and writing in three cyclical components: the forming cycle, the coding cycle, and the reviewing cycle. Explains in each interlock of the cycles are the subprocesses generating, organizing, and editing. Notes that the sensor is centered where all three prime processes overlap, serving to…

Chai, Constance

2002-01-01

317

Coastal zone: battleground and classroom  

Microsoft Academic Search

Survey report:Recent progress in the operation and implementation of coastal zone management programs in the U.S. is surveyed. The provisions of the Coastal Zone Management Act of 1972 are examined. The range of concerns involved in coastal zone management policies, including conservationism, politics, and energy engineering, are thought to fragment the efforts underlying coastal zone studies. Coastal zone problems and

Fairweather

1978-01-01

318

Gas Chemistry in Geothermal Systems  

SciTech Connect

Five new gas geothermometers are introduced. They are useful for predicting subsurface temperatures in water dominated geothermal systems. The geothermometers use data on CO{sub 2}, H{sub 2}S and H{sub 2} concentrations in fumarole steam as well as CO{sub 2}/H{sub 2} and H{sub 2}S/H{sub 2} ratios. It is demonstrated that the gas composition of fumarole steam may be used with or withour drillhole data to evaluate steam condensation in the upflow zones of geothermal systems. Uncertainty exists, however, in distinguishing between the effects of steam condensation and phase separation at elevated pressures. The gas content in steam from discharging wells and the solute content of the water phase can be used to evaluate which boiling processes lead to "excess steam" in the discharge and at which temperature this "excess steam" is added to the fluid moving through the aquifer and into the well. Examples, using field data, are given to demonstrate all the mentioned applications of geothermal chemistry.

Arnorsson, Stefan; Gunnlaugsson, Einar

1983-12-15

319

Atmospheric chemistry research  

SciTech Connect

Global environmental changes are occurring all around us, and the energy industry is a major player in the changes that are taking place. Wise energy policy can only be generated from a position of informed enlightenment and understanding about the environmental consequences of energy production and utilization. The atmospheric chemistry research being conducted at the University of Kentucky's Center for Applied Energy Research is geared toward providing the knowledge necessary to allow industrial and legislative officials to make responsible energy decisions in the 1990's and beyond. Three programs are described: the Kentucky Acid Deposition Program Precipitation chemistry network; modeling of regional and urban photochemistry and acid deposition; and modeling of global tropospheric chemistry.

Saylor, R.D. (Center for Applied Energy Research, Lexington, KY (USA))

1990-01-01

320

Air Composition and Chemistry  

NASA Astrophysics Data System (ADS)

This book is about the atmosphere and humanity's influence on it. For this new edition, Brimblecombe has rewritten and updated much of the book. In the early chapters, he discusses the geochemical, biological and maritime sources of the trace gases. Next, he examines the chemistry of atmospheric gases, suspended particles, and rainfall. After dealing with the natural atmosphere, he examines the sources of air pollution and its effects, with all scenarios updated from the last edition. Scenarios include decline in health, damage to plants and animals, indoor pollution, and acid rain. The final chapters, also revised, are concerned with the chemistry and evolution of the atmospheres of the planets of the solar system. Students with an interest in chemistry and the environmental sciences will find this book highly valuable.

Brimblecombe, Peter

1996-01-01

321

Ammonia chemistry in a flameless jet  

SciTech Connect

In this paper, the nitrogen chemistry in an ammonia (NH{sub 3}) doped flameless jet is investigated using a kinetic reactor network model. The reactor network model is used to explain the main differences in ammonia chemistry for methane (CH{sub 4})-containing fuels and methane-free fuels. The chemical pathways of nitrogen oxides (NO{sub x}) formation and destruction are identified using rate-of-production analysis. The results show that in the case of natural gas, ammonia reacts relatively late at fuel lean condition leading to high NO{sub x} emissions. In the pre-ignition zone, the ammonia chemistry is blocked due to the absence of free radicals which are consumed by methane-methyl radical (CH{sub 3}) conversion. In the case of methane-free gas, the ammonia reacted very rapidly and complete decomposition was reached in the fuel rich region of the jet. In this case the necessary radicals for the ammonia conversion are generated from hydrogen (H{sub 2}) oxidation. (author)

Zieba, Mariusz; Schuster, Anja; Scheffknecht, Guenter [Institute of Process Engineering and Power Plant Technology, University of Stuttgart, Pfaffenwaldring 23, D-70569 Stuttgart (Germany); Brink, Anders; Hupa, Mikko [Process Chemistry Centre, Aabo Akademi University, Biskopsgatan 8, 20500 Aabo (Finland)

2009-10-15

322

Chemistry in water reactors. Reserapport. (Chemistry in water reactors).  

National Technical Information Service (NTIS)

The international conference Chemistry in Water Reactors was arranged in Nice 24-27/04/1994 by the French Nuclear Energy Society. Examples of technical program areas were primary chemistry, operational experience, fundamental studies and new technology. F...

H. P. Hermansson K. Norring

1994-01-01

323

Fourth order connectivity index of polyphenylene dendrimers  

NASA Astrophysics Data System (ADS)

A simple graph G = (V,E) is a finite nonempty set V(G) of objects called vertices together with a (possibly empty) set E(G) of unordered pairs of distinct vertices of G called edges. In chemical graphs, the vertices of the graph correspond to the atoms of the molecule, and the edges represent the chemical bonds. Dendrimers are hyper-branched macromolecules, with a rigorously tailored architecture. They can be synthesized, in a controlled manner, either by a divergent or a convergent procedure. Their applications in chemistry, biology and nano-science are unlimited. A single number which characterizes the graph of a molecular is called a graph theoretical invariant or topological index. The connectivity index is one of the most popular molecular-graph. Recently, some researchers investigated m-order connectivity indices of some dendrimer nanostars, where m = 2 and 3. In this paper, the 4-order connectivity index of an infinite family of polyphenylene dendrimers is investigated.

Hasni, Roslan; Arif, Nabeel Ezzulddin

2013-04-01

324

Anomalous zones (domal)  

SciTech Connect

Each zone contains several anomalous salt properties (anomalous features). Zones cannot be characterized by any single property Zones are highly variable, lenticular, and discontinuous in detail; however, once established, they commonly have a predictable trend. The individual anomalous features can occur alone (locally in pairs) over areas of various sizes and shapes. These alone occurrences are not anomalous zones. Anomalous zones may be of any origin, and origin is not part of the definition. Typical origins include: primary (sedimentary), external sheath zone, separating two spines of salt, or caused by toroidal flow. The major importance of an anomalous zone is that it consists of various anomalous features distributed discontinuously along the zone. Thus, if three or more anomalous properties are observed together, one should look for others. The anomalous zones observed in the Gulf Coast thus far are vertical, linear, and semicontinuous. Most are reasonably straight, but some bend sharply, end abruptly, or coalesce. Textures in salt involve grain size, color (white to dark gray), grain shape, or grain distribution of the salt. Typical anomalous textures are coarse-grain, poikiloblastic, and friability. A change in color is commonplace and seldom anomalous. Structural anomalous features, broadly defined, account for most of the rest of the anomalous features. Not uncommonly they cause mining problems. Among the structural anomalous features: INCLUSIONS: Sediments, hydrocarbons, brine, gases. Common gases are air (as N{sub 2}), CH-compounds, CO{sub 2}, and H{sub 2}S. STRUCTURES: Sheared salt, undue stabbing or jointing, voids (crystal-lined pockets), permeability, increased porosity COMPOSITION: High anhydrite content, visible anhydrite as grains or boudins, very black salt = disseminated impurities such as clay.

Kupfer, D.H. (Louisiana State Univ., Baton Rouge (USA))

1990-09-01

325

Collaborative Physical Chemistry Projects Involving Computational Chemistry  

NASA Astrophysics Data System (ADS)

The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes. They used PM3 and ZINDO calculations to predict the electronic spectra of the molecules and tested the predicted spectra by comparing some with experimental measurements. They also did literature searches for real hair dyes and possible health effects. In the final phase of the project they proposed a synthetic pathway for one compound. In the second project the students were asked to predict which isomer of a small carbon cluster (C3, C4, or C5) was responsible for a series of IR lines observed in the spectrum of a carbon star. After preliminary PM3 calculations, they used ab initio calculations at the HF/6-31G(d) and MP2/6-31G(d) level to model the molecules and predict their vibrational frequencies and rotational constants. A comparison of the predictions with the experimental spectra suggested that the linear isomer of the C5 molecule was responsible for the lines.

Whisnant, David M.; Howe, Jerry J.; Lever, Lisa S.

2000-02-01

326

Mental representation of logical connectives  

Microsoft Academic Search

Logical connectives, such as “AND”, “OR”, “IF... THEN”, and “IF AND ONLY IF” are ubiquitous in both language and cognition; however, reasoning with logical connectives is error?prone. We argue that some of these errors may stem from people's tendency to minimize the number of possibilities compatible with logical connectives and to construct a “minimalist” one?possibility representation. As a result, connectives

Vladimir M. Sloutsky; Yevgeniya Goldvarg

2004-01-01

327

Revitalizing chemistry laboratory instruction  

NASA Astrophysics Data System (ADS)

This dissertation involves research in three major domains of chemical education as partial fulfillment of the requirements for the Ph.D. program in chemistry at Miami University with a major emphasis on chemical education, and concurrent study in organic chemistry. Unit I, Development and Assessment of a Column Chromatography Laboratory Activity, addresses the domain of Instructional Materials Development and Testing. This unit outlines the process of developing a publishable laboratory activity, testing and revising that activity, and subsequently sharing that activity with the chemical education community. A laboratory activity focusing on the separation of methylene blue and sodium fluorescein was developed to demonstrate the effects of both the stationary and mobile phase in conducting a separation. Unit II, Bringing Industry to the Laboratory, addresses the domain of Curriculum Development and Testing. This unit outlines the development of the Chemistry of Copper Mining module, which is intended for use in high school or undergraduate college chemistry. The module uses the learning cycle approach to present the chemistry of the industrial processes of mining copper to the students. The module includes thirteen investigations (three of which are web-based and ten which are laboratory experiments) and an accompanying interactive CD-ROM, which provides an explanation of the chemistry used in copper mining with a virtual tour of an operational copper mine. Unit III, An Alternative Method of Teaching Chemistry. Integrating Lecture and the Laboratory, is a project that addresses the domain of Research in Student Learning. Fundamental Chemistry was taught at Eastern Arizona College as an integrated lecture/laboratory course that met in two-hour blocks on Monday, Wednesday, and Friday. The students taking this integrated course were compared with students taking the traditional 1-hour lectures held on Monday, Wednesday, and Friday, with accompanying 3-hour lab on Tuesday or Thursday. There were 119 students in the test group, 522 students in the Shelton control group and 556 students in the McBride control group. Both qualitative data and quantitative data were collected. A t-test was used to test significance.

McBride, Phil Blake

328

Chemistry in the Kitchen  

NSDL National Science Digital Library

In this kitchen chemistry activity, learners explore the chemistry of crystals by making sugar crystals, consider a common chemical reaction type responsible for the rising of muffins and cake in the oven, and study the cleaning power of soap. For some of the experiments, a molecular-level view is fostered using structural diagrams of the chemicals, along with a fun "cartoon" version of the reaction with molecules represented by colored shapes (both drawn and cut out). The activity is written to be part of a kit that can be checked out of the library, but can be done without the kit.

Shaw, Maisie; Gomez, Maria

2010-01-01

329

Chemistry WebBook  

National Institute of Standards and Technology Data Gateway

SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

330

Chemistry in second life.  

PubMed

This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students. PMID:19852781

Lang, Andrew S I D; Bradley, Jean-Claude

2009-10-23

331

Chemistry in Second Life  

PubMed Central

This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students.

Lang, Andrew SID; Bradley, Jean-Claude

2009-01-01

332

Chemistry in cometary comae.  

PubMed

Significant gas-phase chemistry occurs in the comae of bright comets, as is demonstrated here for the case of Comet Hale-Bopp. The abundance ratio of the two isomers, hydrogen cyanide and hydrogen isocyanide, is shown to vary with heliocentric distance in a way that is consistent with production of HNC by ion-molecule chemistry initiated by the photoionization of water. Likewise, the first maps of emission from HCO+ show an abundance and an extended distribution that are consistent with the same chemical model. PMID:9809016

Irvine, W M; Dickens, J E; Lovell, A J; Schloerb, F P; Senay, M; Bergin, E A; Jewitt, D; Matthews, H E

1998-01-01

333

Chemistry of Transactinides  

NASA Astrophysics Data System (ADS)

In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

Kratz, J. V.

334

Vadose Zone Journal  

NSDL National Science Digital Library

The Vadose Zone Journal is a new publication published by the Soil Science Society of America. The journal is described as "an outlet for interdisciplinary research and assessment of the vadose zone, the mostly unsaturated zone between the soil surface and the permanent groundwater table." A free online trial is currently available to review full text articles until December 31st of 2002. Although the trial includes only the first two issues, the opportunity to search and browse through the publications without charge should be taken advantage of.

Hopmans, J. W. (Jan W.)

2007-07-07

335

Teaching Introductory Organic Chemistry: 'Blooming' beyond a Simple Taxonomy  

NASA Astrophysics Data System (ADS)

Undergraduate students often experience fear and trepidation when studying introductory organic chemistry: the majority of these students use a memorization approach to the material, sacrificing understanding. This paper describes one way the problem can be resolved. The cognitive working level we emphasize in our teaching practice involves making the necessary connections between the general chemistry principles that students have learned (or at least have been exposed to in their senior high school years and have revisited again in their university freshman year) and the many reactions and mechanisms they will encounter in organic chemistry. Educating students early in the course about the various levels of the cognitive process and the necessary working level of cognition for success in organic chemistry teaches connections between the general chemistry principles and reaction mechanisms. This empowers students to approach the subject from a perspective of understanding rather than memorization, and replaces fear and trepidation with confidence. In addition, this can help narrow the gap between what instructors expect from their students and what their students think is sufficient to master the course content.

Pungente, Michael D.; Badger, Rodney A.

2003-07-01

336

The effect of high school chemistry instruction on students' academic self-concept  

NASA Astrophysics Data System (ADS)

The purpose of this study was to investigate the effect of extended instruction in high school chemistry on the academic self-concept of students and determine what parts of the learning experience need to be addressed to make the interaction a more positive one. Fifty-seven students from three metropolitan public schools, who were enrolled in college preparatory chemistry classes, were asked to complete a written instrument, before and after extended chemistry instruction, that measures academic self-concept. Twenty-one of the students who took part in the written task volunteered to answer some in-depth interview questions concerning their academic self-concept and its relationship to chemistry instruction. Student responses, instrument scores, and student chemistry grades were analyzed for a variety of chemistry learning--academic self-concept connections and interactions. Results showed that there was a positive interaction for less than half of the students involved in the interview sessions. The results from the written instrument showed similar findings. Comparing chemistry grades and academic self-concept revealed an uncertain connection between the two, especially for students with strong academic self-concepts. Students felt that the laboratory experience was often disconnected from the remainder of chemistry instruction and recommended that the laboratory experience be integrated with classroom work. Students also expressed concerns regarding the volume of algorithmic mathematical calculations associated with college preparatory chemistry instruction. Results of this study suggest that secondary chemistry instruction must become more aware of the affective domain of learning and develop a mindful awareness of its connection to the cognitive domain if chemistry teaching and learning is going to better facilitate the intellectual growth of secondary students.

Morgan, Peter Wallace

337

33 CFR 334.330 - Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Atlantic Ocean and connecting waters in vicinity of...AREA REGULATIONS § 334.330 Atlantic Ocean and connecting waters in vicinity of...danger zone. The waters of the Atlantic Ocean and connecting waters within an area described as follows:...

2013-07-01

338

33 CFR 334.330 - Atlantic Ocean and connecting waters in vicinity of Myrtle Island, Va.; Air Force practice...  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Atlantic Ocean and connecting waters in vicinity...AREA REGULATIONS § 334.330 Atlantic Ocean and connecting waters in vicinity...danger zone. The waters of the Atlantic Ocean and connecting waters within an area described as...

2009-07-01

339

Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.  

ERIC Educational Resources Information Center

This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

340

Distribution and evolution of water chemistry in Heihe River basin  

Microsoft Academic Search

Surface- vs. ground-water chemistry in the Heihe River basin, assessed through field sampling of precipitation, surface water and groundwater, allowed geographical zones and chemical types to be differentiated. The geographical zones included: alpine ice-snow (>3,900 m), alpine meadow (3,400–3,900 m), mountain forest and shrub (2,600–3,400 m), mountain grassland (1,900–2,600 m) and desert grassland (1,500–1,900 m). Groundwater chemical types included: (1) mountain fissure and piedmont gravel,

Q. Feng; W. Liu; Y. H. Su; Y. W. Zhang; J. H. Si

2004-01-01

341

Service-Learning in Introductory Chemistry: Supplementing Chemistry Curriculum in Elementary Schools  

NASA Astrophysics Data System (ADS)

The pedagogy of service-learning is becoming an accepted method of connecting college classrooms to the community. A service-learning course component has been successfully incorporated into the second quarter of Introductory Chemistry (Chem 120) at Kalamazoo College. Students in Chem 120 design inquiry-based laboratory experiments related to course material for students in grades K 6. The Chem 120 students then conduct these experiments with assigned classes at a local elementary school. This project reinforces course material for the college students while supplementing the elementary school's science curriculum and exposing children to topics they otherwise would not learn. In addition to providing a context for college students to make connections between textbook concepts and real life processes, this project also offers a chance to improve other skills, such as problem solving and communication. Surveys of the Chem 120 students and comments from the elementary school community demonstrate that the project is successful overall and is a way to interest students at all levels in chemistry. This paper discusses the methods used to conduct and assess this service-learning project, survey results, comments from the elementary school community, and the effect of this project on the number of chemistry majors at Kalamazoo College.

Esson, Joan M.; Stevens-Truss, Regina; Thomas, Anne

2005-08-01

342

Organic Chemistry, 5th Edition  

NSDL National Science Digital Library

Finds ChemEd DL resources related to the sections of the Organic Chemistry textbook, Organic Chemistry, 5th Edition, by William H. Brown, Christopher S. Foote, Brent L. Iverson, Eric Anslyn published by Brooks/Cole, 2009.

343

The Lighter Side of Chemistry.  

ERIC Educational Resources Information Center

Discusses the rationale for using photochemistry to merge descriptive chemistry and molecular orbital theory in first-year chemistry courses. Includes procedures and safety information for various activities, demonstrations, and experiments involving photochemical reactions. (DH)

Lamb, William G.

1984-01-01

344

The Art of Teaching Chemistry.  

ERIC Educational Resources Information Center

|Contains descriptions of 11 college chemistry education programs that were awarded grants by the Pfizer Foundation because they make the introductory chemistry experience more positive and engaging for students, especially women and minorities. (LZ)|

Lloyd, Baird W., Ed.

1994-01-01

345

Special Report: Chemistry of Comets.  

ERIC Educational Resources Information Center

|Discusses the chemistry of comets. How comets provide clues to the birth of the solar system, photolytic reactions on comets involving water, chemical modeling, nuclear chemistry, and research findings are among the areas considered. (JN)|

A'Hearn, Michael F.

1984-01-01

346

The Ethics Connection  

NSDL National Science Digital Library

Created and maintained by the Markkula Center for Applied Ethics at Santa Clara University, the Ethics Connection demonstrates the power of the Web as an interactive information and communication medium. This site combines excellent content, form, and function to provide teachers, researchers, community leaders, and the public "with strategies to heighten ethical awareness and improve ethical decision making." The rich information resources at the Ethics Connection include an interactive forum for the discussion of ethical issues; an extensive collection of the latest news and publications on ethics, featuring the Markkula Center's own quarterly, Issues in Ethics; a collection of several case studies on ethics, which include message boards for visitors' comments; a Practicing Ethics section, offering numerous resources for day-to-day ethical decision making; and a compilation of 900 ethical links, all of which are categorized, rated, and reviewed.

347

The Habitable Zone  

NSDL National Science Digital Library

This illustration is an approximate representation of the planets in our solar system and their relation to what scientists call The Habitable Zone. The planet distances from the sun are measured in Astronomical Units (AU) and are not to scale.

2008-03-26

348

Zoning Ordinance, Junction City.  

National Technical Information Service (NTIS)

The zoning ordinance - resolution is a regulatory measure or implementation device which is to be used in conjunction with the Boyle County comprehensive planning program. This ordinance is intended to insure the orderly growth and development of the plan...

1969-01-01

349

Zoning Ordinance, Brentwood, Tennessee.  

National Technical Information Service (NTIS)

Purpose of the zoning regulations and districts and statement of compliance with Tennessee Enabling Legislation. A list of definitions of terms is included. General provisions which affect all districts are enumerated. The various districts are defined an...

1972-01-01

350

Coastal Zone Boundaries.  

National Technical Information Service (NTIS)

This report is the second in a series of working papers which will be issued to interested citizens and governmental officials so that they may actively and effectively participate in the development of Delaware's Coastal Zone Management Program. Regulati...

1976-01-01

351

The Brain Connection  

NSDL National Science Digital Library

The Scientific Learning Corporation maintains the Brain Connection, a Web site "dedicated to providing accessible, high-quality information about how the brain works and how people learn." This extensive site has descriptions, pictures, animations, puzzles, quizzes and much more on nearly every aspect of the human brain. Everyone from kids to adults will find hours of interesting and fun exploration at this well-constructed Web site.

2008-11-13

352

Comparing Connection Cubes  

NSDL National Science Digital Library

Students explore five models of subtraction (counting, sets, number line, balanced equations, and inverse of addition) using connecting cubes. The lessons focus on the comparative mode of subtraction. In them, children explore the relationship between addition and subtraction, write story problems in which comparison is required, and practice the subtraction facts. The unit consists of lessons that build on and extend early understandings about counting, addition, and subtraction in the comparative mode.

Math, Illuminations N.

2009-01-05

353

The CONNECT Architecture  

Microsoft Academic Search

\\u000a Current solutions to interoperability remain limited with respect to highly dynamic and heterogeneous environments, where\\u000a systems encounter one another spontaneously. In this chapter, we introduce the Connect architecture, which puts forward a fundamentally different method to tackle the interoperability problem. The philosophy\\u000a is to observe networked systems in action, learn their behaviour and then dynamically generate mediator software which will

Paul Grace; Nikolaos Georgantas; Amel Bennaceur; Gordon Blair; Franck Chauvel; Valérie Issarny; Massimo Paolucci; Rachid Saadi; Betrand Souville; Daniel Sykes

354

Connectivity of random nets  

Microsoft Academic Search

The weak connectivity ? of a random net is defined and computed by an approximation method as a function ofa, the axone density. It is shown that ? rises rapidly witha, attaining 0.8 of its asymptotic value (unity) fora=2, where the number of neurons in the net is arbitrarily large. The significance of this parameter is interpreted also in\\u000a terms

Ray Solomonoff; Anatol Rapoport

1951-01-01

355

Linking the Microscopic View of Chemistry to Real-Life Experiences: Intertextuality in a High-School Science Classroom  

ERIC Educational Resources Information Center

|Chemistry learning involves establishing conceptual relationships among macroscopic, microscopic, and symbolic representations. Employing the notion of intertextuality to conceptualize these relationships, this study investigates how class members interactionally construct meanings of chemical representations by connecting them to real-life…

Wu, Hsin-Kai

2003-01-01

356

The Big Picture; A Classroom Activity for Organic Chemistry  

NSDL National Science Digital Library

In the article "The Big Picture: A Classroom Activity for Organic Chemistry", Thomas Poon makes interesting use of the device exploited by Istvan Banyai in his Zoom books to help students of organic chemistry make connections between the molecular world and ways in which those molecules are important in daily life. The paper should have appeal at all levels of science education from the time the idea of molecules is first introduced through college-level courses. Along the way, students will encounter important biological molecules (such as chlorophyll), inks (such as pen ink), CFCs, hydrocarbon fuels, plastics (such as Lexan polycarbonate), and molecules with medical applications (such as aspirin and novocaine).

357

Chemistry of soil aluminum  

Microsoft Academic Search

Better understanding of soil aluminum has had dramatic effects on the interpretation of many aspects of soil chemistry. Aluminum is a Group III element, metallic in nature, and exhibits both ionic and cuvaient bonding. It is the most plentiful of all metallic cations of the earth's crust. It is released from octahedral coordination with oxygen in minerals by weathering processes.

E. O. McLean

1976-01-01

358

Chemistry by the Case  

NSDL National Science Digital Library

This article describes the structure and content of a one-semester course dealing with chemistry, science, and technology designed for nonscience majors. The course uses a hybrid of two active learning methodologies--problem-based team learning and the cas

Dinan, Frank J.

2002-09-01

359

Bioconjugation in pharmaceutical chemistry  

Microsoft Academic Search

Polymer conjugation is of increasing interest in pharmaceutical chemistry for delivering drugs of simple structure or complex compounds such peptides, enzymes and oligonucleotides. For long time drugs, mainly with antitumoral activity, have been coupled to natural or synthetic polymers with the purpose of increasing their blood permanence time, taking advantage of the increased mass that reduces kidney ultrafiltration. However only

F. M. Veronese; M. Morpurgo

1999-01-01

360

The Language of Chemistry.  

ERIC Educational Resources Information Center

|Describes a new curriculum called The Language of Chemistry designed to illustrate how problems of biological and/or medical importance can be understood on a molecular basis and to show that the logic, knowledge, and language needed are easily accessible. Among the case studies in the curriculum are the giant peacock moth, bacterial chemotaxis,…

Bretz, Stacey Lowery; Meinwald, Jerrold

2002-01-01

361

General Chemistry, 1970 Edition.  

ERIC Educational Resources Information Center

|This publication is a syllabus for a senior high school chemistry course designed for the average ability, nonscience major. The content of the syllabus is divided into three basic core areas: Area I: Similarities and Dissimilarities of Matter (9 weeks); Area II: Preparation and Separation of Substances (10 weeks); Area III: Structure and…

Dunham, Orson W.; Franke, Douglas C.

362

Green chemistry metrics  

EPA Science Inventory

Synthetic chemists have always had an objective to achieve reliable and high-yielding routes to the syntheses of targeted molecules. The importance of minimal waste generation has emphasized the use of green chemistry principles and sustainable development. These directions lead ...

363

Array processors in chemistry  

SciTech Connect

The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

Ostlund, N.S.

1980-01-01

364

Ziptop Bag Chemistry  

NSDL National Science Digital Library

In this chemistry activity, learners perform three chemical reactions in a sealed zip-top bag. Learners will record their observations and classify the changes as chemical or physical. This resource includes questions for answers to help learners interpret their observations and better understand chemical reactions. The answers to these questions are included on the resource guide.

House, The S.

2013-05-15

365

Chemistry Cook-Off  

ERIC Educational Resources Information Center

|For this activity, high school chemistry students compete in a cooking contest. They must determine the chemical and physical changes that occur in the food they prepare, present their recipe as a step-by-step procedure similar to a lab procedure, identify chemicals in the food, and present all measurements in both metric and English units. The…

McCormick, Cynthia

2012-01-01

366

Chemistry in the Troposphere.  

ERIC Educational Resources Information Center

|Topics addressed in this review of chemistry in the troposphere (layer of atmosphere extending from earth's surface to altitude of 10-16km) include: solar radiation/winds; earth/atmosphere interface; kinetic studies of atmospheric reactions; tropospheric free-radical photochemistry; instruments for nitric oxide detection; sampling…

Chameides, William L.; Davis, Douglas D.

1982-01-01

367

Online Organic Chemistry  

ERIC Educational Resources Information Center

This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

Janowicz, Philip A.

2010-01-01

368

Online organic chemistry  

NASA Astrophysics Data System (ADS)

This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online office hours were found to be effective, and discussion sessions can be placed online as well. A model was created that explains 36.1% of student performance based on GPA, ACT Math score, grade in previous chemistry course, and attendance at various forms of discussion. Online exams have been created which test problem-solving skills and is instantly gradable. In these exams, students can submit answers until time runs out for different numbers of points. These facets were combined effectively to create an entirely online organic chemistry course which students prefer over the in-person alternative. Lastly, there is a vision for where online organic chemistry is going and what can be done to improve education for all.

Janowicz, Philip A.

369

Problems of space chemistry  

Microsoft Academic Search

The main problems of space chemistry are examined, including the origin and abundance of chemical elements, their migration to different regions of the universe, the formation of the chemical composition of cosmic bodies, and the chemical evolution of the solar system and the origin of life. Based on current astrophysical and space-chemical data, the main stages of the evolution of

Georgii V. Voitkevich

1987-01-01

370

News: Green Chemistry & Technology  

EPA Science Inventory

A series of 21 articles focused on different features of green chemistry in a recent issue of Chemical Reviews. Topics extended over a wide range to include the design of sustainable synthetic processes to biocatalysis. A selection of perspectives follows as part of this colu...

371

ADVANCED CHEMISTRY BASINS MODEL  

Microsoft Academic Search

The advanced Chemistry Basin Model project has been operative for 48 months. During this period, about half the project tasks are on projected schedule. On average the project is somewhat behind schedule (90%). Unanticipated issues are causing model integration to take longer then scheduled, delaying final debugging and manual development. It is anticipated that a short extension will be required

William Goddard; Lawrence Cathles; Mario Blanco; Paul Manhardt; Peter Meulbroek; Yongchun Tang

2004-01-01

372

Advances in analytical chemistry  

Microsoft Academic Search

The requirement to increase our understanding and control of processes has accelerated development of chemical sensor and analyzer technology. Analytical chemists anticipated the requirement to reduce the time between sampling and reporting the results. Multivariate statistical analyses when implemented on dedicated computers controlling modern instruments provide a mechanism for real time monitors. Implementation of these advanced techniques of analytical chemistry

William F. Arendale; Gary L. Workman

1993-01-01

373

The Pimlico Chemistry Trail.  

ERIC Educational Resources Information Center

|Describes a chemistry "trail" (similar to a nature trail) which focuses on chemical phenomena in the environment. The trail includes 20 stops in and around a local school. Types of phenomena examined include building materials, air pollution, corrosion of metals, swimming pools, and others. Additional activities are also suggested. (DH)|

Borrows, Peter

1984-01-01

374

Water Chemistry Laboratory Manual.  

ERIC Educational Resources Information Center

|This manual of laboratory experiments in water chemistry serves a dual function of illustrating fundamental chemical principles of dilute aqueous systems and of providing the student with some familiarity with the chemical measurements commonly used in water and wastewater analysis. Experiments are grouped in categories on the basis of similar…

Jenkins, David; And Others

375

Online Organic Chemistry  

ERIC Educational Resources Information Center

|This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

Janowicz, Philip A.

2010-01-01

376

Water Chemistry Laboratory Manual.  

ERIC Educational Resources Information Center

This manual of laboratory experiments in water chemistry serves a dual function of illustrating fundamental chemical principles of dilute aqueous systems and of providing the student with some familiarity with the chemical measurements commonly used in water and wastewater analysis. Experiments are grouped in categories on the basis of similar…

Jenkins, David; And Others

377

Get Cooking with Chemistry!  

ERIC Educational Resources Information Center

|This book presents science activities investigating the chemical changes and reactions with powders that are used in baking. Activities include: (1) Mystery Powders; (2) Find the Fizz: Discover the Secret of Baking Powder; and (3) A Feast for Yeast and Cheese: Behold the Power of Chemistry. (YDS)|

American Chemical Society, Washington, DC.

378

The Pimlico Chemistry Trail.  

ERIC Educational Resources Information Center

Describes a chemistry "trail" (similar to a nature trail) which focuses on chemical phenomena in the environment. The trail includes 20 stops in and around a local school. Types of phenomena examined include building materials, air pollution, corrosion of metals, swimming pools, and others. Additional activities are also suggested. (DH)

Borrows, Peter

1984-01-01

379

Chemistry by Computer.  

ERIC Educational Resources Information Center

Describes the features of various computer chemistry programs. Utilization of computer graphics, color, digital imaging, and other innovations are discussed in programs including those which aid in the identification of unknowns, predict whether chemical reactions are feasible, and predict the biological activity of xenobiotic compounds. (CS)

Garmon, Linda

1981-01-01

380

Advanced Chemistry Development (ACD)  

NSDL National Science Digital Library

ACD provides a large set of chemistry software. ChemSketch and Chem 3-D include freely downloadable versions. ChemSketch can be used for drawing and publishing chemical structures; Chem 3-D can be used for three dimensional visualization, and includes a molecular mechanics geometry optimizer.

381

Interstellar Organic Chemistry  

Microsoft Academic Search

Complex organic molecules that are stable against radiation may pervade interstellar space, with their degradation products a source of those molecules observed. The connexion between biological and interstellar organic chemistry is, however, analogical rather than substantive, and the prospect for interstellar biology is dim. This article is based on Professor Sagan's contribution to a symposium at the National Radio Astronomy

Carl Sagan

1972-01-01

382

Epoxying Isoprene Chemistry  

EPA Science Inventory

It seems that every few months we read about another missing aspect of atmospheric chemistry: missing products, missing reactivity, missing sources, missing understanding. Thus, it is with some relief that we read in this issue the paper of Paulot et al. The paper provides more...

383

Getting Reactions to Chemistry.  

ERIC Educational Resources Information Center

|"COMETS on Careers" describes science-related careers, introduces activities illustrating a science concept being studied, and encourages use of professional persons as activity leaders. Several COMETS chemistry activities are described. These activities, which can be performed in school or at home, focus on colloids, acid/base indicators, and…

Smith, Walter S.

1983-01-01

384

The Language of Chemistry.  

ERIC Educational Resources Information Center

Describes a new curriculum called The Language of Chemistry designed to illustrate how problems of biological and/or medical importance can be understood on a molecular basis and to show that the logic, knowledge, and language needed are easily accessible. Among the case studies in the curriculum are the giant peacock moth, bacterial chemotaxis,…

Bretz, Stacey Lowery; Meinwald, Jerrold

2002-01-01

385

Chemistry in Bioinformatics  

Microsoft Academic Search

Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is Openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the

Peter Murray-rust; John B. O. Mitchell; Henry S. Rzepa

2005-01-01

386

The Chemistry of Health  

ERIC Educational Resources Information Center

|Do people realize that chemistry plays a key role in helping solve some of the most serious problems facing the world today? Chemists want to find the building blocks of the chemical universe--the molecules that form materials, living cells and whole organisms. Many chemists are medical explorers looking for new ways to maintain and improve…

Davis, Alison

2009-01-01

387

The Chemistry of Health.  

ERIC Educational Resources Information Center

|This booklet, geared toward an advanced high school or early college-level audience, describes how basic chemistry and biochemistry research can spur a better understanding of human health. It reveals how networks of chemical reactions keep our bodies running smoothly. Some of the tools and technologies used to explore these reactions are…

National Inst. of General Medical Sciences (NIH), Bethesda, MD.

388

Analytical Chemistry in Poland  

Microsoft Academic Search

The paper presents the main achievements of analytical chemistry in Poland on the basis of papers published mainly in the last decade. The selection is somewhat arbitrary but should show the most important directions of research. The citations generally refer to papers published in regular journals. The following topics were discussed: general aspects, chemical methods and reagents, spectrophotometry, speciation studies,

Adam Hulanicki; Zygfryd Witkicewicz

2000-01-01

389

From Chemistry To Culture  

Microsoft Academic Search

Chemistry deals with atoms and molecules, and anybody who views interactions of matter on that level and who successfully resolves problems on that level is a chemist. Many environmental problems can be solved by chemists working, technically speaking, at the molecular level. But when the solution is presented to the public at the socio-economic level or in socio-economic terms, the

W. A. Bridgeo; H. J. Labelle

1991-01-01

390

Chemistry of the natural atmosphere  

Microsoft Academic Search

The fundamental principles of atmospheric chemistry are examined in a textbook for graduate science students. Topics addressed include the bulk composition, structure, and dynamics of the atmosphere; photochemical processes and elementary reactions; the chemistry of the stratosphere; tropospheric chemistry and the methane oxidation cycle; and ozone in the troposphere. Consideration is given to volatile hydrocarbons and halocarbons, the atmospheric aerosol,

Peter Warneck

1988-01-01

391

Department of Chemistry at NYU  

NSDL National Science Digital Library

On this site, New York University Department of Chemistry presents its various research interests including Chemical Biology, Biomolecular and Biophysical Chemistry, and Biomedical Chemistry. In each section, visitors can learn about NYU faculty, their publications, and visit their homepages often with links to course and laboratory educational materials in biochemistry.

2008-03-06

392

Chemistry degree curricula — undergraduate feelings  

Microsoft Academic Search

The end-of-first year attitudes towards chemistry, the degree to which course expectations matched realisations, and examination scores were available for 110 Belgian freshman chemistry majors. Four years later, data of subsequent “careers” enabled the students (Ss) to be classified in four groups: those who continued as chemistry majors throughout their university studies; those who changed their major study but stayed

D. Neerinck; C. R. Palmer

1983-01-01

393

Six Pillars of Organic Chemistry  

ERIC Educational Resources Information Center

|This article describes an approach to teaching organic chemistry, which is to have students build their knowledge of organic chemistry upon a strong foundation of the fundamental concepts of the subject. Specifically, the article focuses upon a core set of concepts that I call "the six pillars of organic chemistry": electronegativity, polar…

Mullins, Joseph J.

2008-01-01

394

Wayne Steinmetz Chemistry Education Resources  

Microsoft Academic Search

The Wayne Steinmetz Chemistry Education Resources Collection provides a thorough and introspective look at the vast body of work produced by Dr. Wayne Steinmetz in the course of his commitment to chemistry education at Pomona College. The collection contains numerous professional resources and research materials related to the teaching of chemistry including but not limited to syllabi, sample homework assignments

Wayne E. Steinmetz

2010-01-01

395

Conditional stochastic mapping of transport connectivity  

NASA Astrophysics Data System (ADS)

We present a method for the stochastic simulation of point-to-point transport connectivity honoring data from three types of information: (1) travel time estimates obtained from field tracer tests; (2) estimates of flow connectivity indicators obtained from the relatively fast or slow flow response that is observed at a point location given the flow impulse at another location, and (3) measurements of transmissivity at a local scale. The method thus efficiently integrates data obtained from different hydraulic tests, each sampling different areas within the aquifer. To achieve this, we first extend the concept of point-to-point flow connectivity and transport connectivity, mathematically formulated by Trinchero et al. (2008) for pumping conditions, to support a more general flow configuration. Interestingly, point-to-point flow connectivity can be generally seen as a weighted integral of transmissivity over the entire domain, the weighting function being proportional to the sensitivity of heads with respect to the natural log of transmissivity per unit of aquifer volume. On the contrary, point-to-point transport connectivity is a weighted integral along the particle path of the solute mass that involves two variables: transmissivity and flow connectivity. Each variable has its own distinct weighting function. The weighting function of transmissivity is inversely proportional to both the homogeneous travel time and the point velocity sampled along the travel path. On this basis, we show how to generate conditional point-to-point transport connectivity maps. The method avoids the inference of cross-covariance functions between variables measured over different scales and sampled areas (which cannot be otherwise estimated with a few data measurements) by expressing them as a function of the local transmissivity covariance function. An example of the method is provided to evaluate the worth of including tracer data to delineate capture zones of abstraction wells originally defined from local transmissivity measurements. Monte Carlo simulations reveal that the impact of including tracer data is a maximum when the travel time data are obtained at a location different than that of transmissivity measurements. The reason is that weighting functions give larger weights to the injection location, so introducing tracer test data at points where transmissivity is already known is somewhat redundant.

Fernã Ndez-Garcia, D.; Trinchero, P.; Sanchez-Vila, X.

2010-10-01

396

Conditional Stochastic Mapping of Transport Connectivity  

NASA Astrophysics Data System (ADS)

We present a method for the stochastic simulation of point-to-point transport connectivity honoring data from three types of information: (a) travel time estimates obtained from field tracer tests; (b) estimates of flow connectivity indicators obtained from the relatively fast or slow flow response that is observed at a point location given the flow impulse at another location; and (c) measurements of transmissivity at a local scale. The method thus efficiently integrates data obtained from different hydraulic tests, each one sampling different areas within the aquifer. To achieve this, we first extend the concept of point-to-point flow connectivity and transport connectivity, mathematically formulated by Trinchero et al. (2008) for pumping conditions, to support a more general flow configuration. Interestingly, point-to-point flow connectivity can be generally seen as a weighted integral of transmissivity over the entire domain, the weighting function being proportional to the sensitivity of heads with respect to the natural log of transmissivity per unit of aquifer volume. On the contrary, point-to-point transport connectivity is a weighted integral along the particle path of the solute mass that involves two variables: transmissivity and flow connectivity. Each variable has its own distinct weighting function. The weighting function of transmissivity is inversely proportional to both the homogeneous travel time and the point velocity sampled along the travel path. Based on this, we show how to generate conditional point-to-point transport connectivity maps. The method avoids the inference of cross-covariance functions between variables measured over different scales and sampled areas (which cannot be otherwise estimated with a few data measurements), by expressing them as a function of the local transmissivity covariance function. An example of the method is provided to evaluate the worth of including tracer data to delineate capture zones of abstraction wells originally defined from local transmissivity measurements. Monte Carlo simulations reveal that the impact of including tracer data is maximum when the travel time data is obtained at a different location than that of transmissivity measurements. The reason is that weighting functions gives larger weights to the injection location, and so introducing tracer test data at points where transmissivity is already known is somewhat redundant.

Sanchez-Vila, Xavier; Fernández-Garcia, Daniel; Trinchero, Paolo

2010-05-01

397

The chemistry of lake sediments in time and space  

Microsoft Academic Search

Five short cores (1.0–1.5 m) representing different depositional zones of an isolated bay of Lake Minnetonka, Minnesota (USA), were independently dated by 210Pb and pollen analysis and were analyzed stratigraphically for elemental chemistry (following sediment fractionation) and sedimentary pigments (including myxoxanthophyll and oscillaxanthin). Because of good dating control, short-interval time-stratigraphic units could be traced across the basin, and lake-wide accumulation

Daniel R. Engstrom; Edward B. Swain

1986-01-01

398

Promoting Scientific Literacy Using a Sociocritical and Problem-Oriented Approach to Chemistry Teaching: Concept, Examples, Experiences  

ERIC Educational Resources Information Center

This paper revisits the discussion about the objectives of scientific literacy-oriented chemistry teaching, its connection to the German concept of "Allgemeinbildung", and the debate of "science through education" vs. "education through science". About 10 years ago the sociocritical and problem-oriented approach to chemistry teaching was suggested…

Marks, Ralf; Eilks, Ingo

2009-01-01

399

Structures and Stability of Lifted Combustion Zones in Preheated Oxidizer  

NASA Astrophysics Data System (ADS)

The structures and stability of lifted combustion zones have been simulated with detailed chemistry and transport properties in an axisymmetric laminar fuel (CH4) jet and outer co-flow of the (O2+N2) oxidizer whose initial temperature is 300K, 700K and 1200K. A set of numerical simulations was executed by increasing the N2 dilution ratio, Z (mole fraction of N2 in the oxidizer). The results showed that at 300K, the lifted combustion zone had a triple flame structure where the rich premixed wing is smaller than the lean one and the trailing diffusion flame immediately inclined to the fuel side from the triple point as well as the leading edge of the triple flame was shifted away from the jet axis as Z increased. As the initial temperature increased, the combustion zones were lifted at larger Z values than the one at 300K. Especially, for 1200K, it was found that the lifted combustion zones, when expressed in terms of the heat release rate, have become so weak that a flameless triple combustion zone was formed due to the high dilution ratio and high preheat temperature. The numerical simulations on the response of the lifted triple combustion zone to the initial fuel velocity were also carried out, and the results showed that the lifted combustion zone using a high preheated temperature was very stable in the near field.

Ruan, Jiongming; Kobayashi, Hideaki; Niioka, Takashi; Abuliti, Abudula; Iida, Fumio

400

33 CFR 150.355 - How are other vessels cleared to move within the safety zone?  

Code of Federal Regulations, 2013 CFR

...vessel operations is required before a vessel, other than a tanker or support vessel, enters the safety zone. (b) The...system, paragraphs (a) and (b) of this section apply once a tanker connects to the STL...

2013-07-01

401

A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula  

NASA Astrophysics Data System (ADS)

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords `context-based', `contextual learning' and `chemistry education' in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context- based chemistry studies, for future research in context- based chemistry studies, and for curriculum developers in context- based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students.

Ültay, Neslihan; Çal?k, Muammer

2012-12-01

402

A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula  

NASA Astrophysics Data System (ADS)

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords `context-based', `contextual learning' and `chemistry education' in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context-based chemistry studies, for future research in context-based chemistry studies, and for curriculum developers in context-based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students.

Ültay, Neslihan; Çal?k, Muammer

2011-12-01

403

University of Minnesota Chemistry Outreach  

NSDL National Science Digital Library

At this website, the University of Minnesota supplies numerous chemistry experiments. The activities are divided into two categories: demos and recipe cards. The demonstrations, which usually require a chemistry lab setting and chemistry supplies, are helpful for chemistry teachers in a classroom environment. The recipe cards, however, can usually be easily performed in the home. For example, students can learn about osmosis with a simple demonstration using an egg, vinegar, and water. The website features a short checklist to help visitors become better scientists. With a quick visit to this site, users can find fun activities to enhance the chemistry learning experience.

404

[Stereological analysis of human gingival connective tissues. Clinically healthy gingiva].  

PubMed

The purpose of this study was to analyse stereologically the composition of the human gingival connective tissue after a period to two weeks of intense oral hygiene. Thiry young adults participated in this study. A clinical examination (plaque index and gingival index) was made at day 0 and day 14: on this last day an interdental papilla in the premolar region was sampled. The stereological analysis on point integration field has been made on serial sections of the interdental papillae sectioned in a buccal lingual plane. The gingivodental status of the subjects after the period of intense hygiene was characterized by a total absence of dental plaque and signs of gingival inflammation. The connective tissue was mainly made of by a dense network of collagen fibers. However an infiltrated zone of inflammatory cells (about 25% of the connective tissue) was always present. As a whole the gingival connective tissue was made of 88.4% of collagen, 7.3% of blood and lymph vessels, 4.9% of edema, 8.4% of fibroblasts, 8.2% of inflammatory cells and 2.7% of residual tissue (unidentified cells, nerves...). The infiltrated zone showed a certain number of differences with the non-infiltrated zone (collagen decrease, increase in oedema, vessels and mainly in inflammatory cells, principally monocytes, polymorphonuclear leukocytes and lymphocytes). PMID:6930378

Daniel, A; Dupont, M

1980-06-01

405

Helping Students Make Connections  

NSDL National Science Digital Library

Science teachers want their students to attain scientific literacy for applications beyond the classroom. Unfortunately, many students view school, and especially school science, as disconnected from their lives and interests. Project-based science (PBS) is a powerful way to help students make connections between school science and the community. However, it can be difficult to enact in the high school classroom. As a result, the author developed a focus sheet to guide students through the complexity of PBS. This organizational tool provides students with parameters for the multiple tasks necessary to successfully accomplish the project.

Nelson, Tamara H.

2004-03-01

406

Achieving Interorganizational Connectivity  

Microsoft Academic Search

Electronic business between enterprises requires interorganizational connectivity–either between humans and machines, or between\\u000a machines and machines. Whereas human-machine communication in eBusiness reflects the B2C scenario, where the customer orders\\u000a products via a web browser, machine-machine interactions are common in B2B scenarios, where two machines exchange business\\u000a messages. Due to asymmetries in size and levels of technical sophistication among the business

Ursula Hübner

407

Playing Connect Three  

NSDL National Science Digital Library

This activity promotes students to explore and analyze the number of different ways of achieving each of the specific outcomes when adding and subtracting positive and negative integers while playing the game, "Connect Three." By answering key questions, the players work out a strategy for improving their chances of winning the game. The Teachers' Notes page offers suggestions for implementation, discussion questions, ideas for support, extension and answers to questions are provided. A pdf of the game board and a spreadsheet to simulate tossing the dice are linked.

2008-01-01

408

Magnificent Ground Water Connection  

NSDL National Science Digital Library

The Magnificent Ground Water Connection is a compilation of ground water-related activities for teaching and learning purposes. The teacher's activity guide is applicable to a wide range of subject matter and the ground water theme is integrated into stories, songs, math, social studies, art and writing. The topics include basic concepts of the water cycle, water distribution, treatment and stewardship. Other subjects include the water cycle and water conservation, New England's ground water resources, ground water contamination and protection. Sections are also available for wetlands, ground water, marine debris, waster, air quality, acid rain, and energy. Users can also access an on-line lending library for educational materials and videos.

409

Connecting Meaning and Mathematics  

NSDL National Science Digital Library

This page contains step-by-step tutorials and guided inquiry activities that are designed to help students discover physical properties and concepts by developing understanding from mathematics. Problem-solving techniques and equation-solving are also discussed. Most of this material is written for upper level classical mechanics courses, but some are meant for other courses. Connections are made with the Intermediate Mechanics Tutorials by Ambrose and Wittmann. Supplementary homework sets are available for some labs. All materials are available in Word and PDF formats.

Meredith, Dawn

2008-08-01

410

Informatics aided design of crystal chemistry  

NASA Astrophysics Data System (ADS)

The search and design of new materials can be significantly aided by combinatorial experiments. However the key to minimizing the search process in combinatorial experiments is to identify the key combinations that achieve the desired functionality in the class of materials being studied. The concept of virtual combinatorial experiments for materials selection and design strategy is useful to show how one may design combinatorial libraries a priori by integrating data mining techniques with physically robust multivariate data. In this thesis, using crystal chemistry of spinel nitrides as a framework for materials design, the methodology for integrating derived variables using newly proposed mixing rules based on statistical tools such as Partial Least Squares (PLS) and Principal Component Analysis (PCA) is described. Strategically selecting appropriate quantum mechanical and crystallographic data are used to predict and identify new alloy chemistries, modulus properties, and phase stabilities. This approach is unique in materials design because it overcomes problems of length scale by connecting the microscopic phenomena and macroscopic engineering properties. The integration of the physics based predictions with data mining predictions is used to propose new virtual compounds, especially with higher order or multicomponent chemistries. With the predicted target properties (bulk moduli and phase stabilities) by PLS, correlations between all variables in a created library of binary and ternary spinel nitrides is visualized in the dimensionally reduced structure maps created by PCA. Through these activities, materials informatics plays an important role in guiding the choice of the most promising chemistries that exhibit the desired functionality in the virtual combinatorial libraries of hypothetical materials.

Suh, Changwon

411

Institutional Creativity: The Relational Zone of Proximal Development  

Microsoft Academic Search

In this article I argue that creative acts cannot be confined to the individual. Creativity can be seen as a meeting between an individual and a wider activity system. This argument is related to the claim that a zone of proximal development (ZPD), the concept connected to the culturalhistorical psychologist Lev Vygotsky, is both an internal and an external relation

Cathrine Hasse

2001-01-01

412

Soil gas radon: a tool for exploring active fault zones  

Microsoft Academic Search

The profile of soil gas radon was monitored in five active fault sites in northern and northwestern Greece. Measurements were carried out during summer months, using CR-39 solid state nuclear track detectors (SSNTDs). The spatial distribution of radon along lines traversing the fault zones revealed anomalies, clearly connected to the local tectonic structure. Specifically, increased radon signals evolved on the

K. Ioannides; C. Papachristodoulou; K. Stamoulis; D. Karamanis; S. Pavlides; A. Chatzipetros; E. Karakala

2003-01-01

413

Connective tissue tumors.  

PubMed

Connective tissue consists of collagen, elastic fibers and ground substances produced by fibrocytes. These cells are usually spindle-shaped with slender nuclei and bipolar cytoplasmic extensions. Apart from labeling for vimentin and variable reactivity for factor XIIIa and CD34, fibrocytes are immunonegative. Electron microscopy reveals prominent endoplasmic reticulum, but is otherwise indistinct. Lesions with fibrocytic differentiation can be divided into five categories: scars, keloids, dermatofibromas, nodular fasciitis, and superficial fibromatoses are inflammatory lesions. Thereby, dermatofibromas and their subcutaneous/deep soft tissue counterpart nodular fasciitis can present with a wide variety of clinicopathologic variants which may be misinterpreted as malignancies. Prurigo nodularis, chondrodermatitis nodularis helicis, acanthoma fissuratum, and knuckle pads are hyperplasias; fibroma molle, fibrous papules, connective tissue nevi, and elastofibroma are hamartomas; and fibroma of tendon sheath, pleomorphic fibroma, and giant cell tumor of tendon sheath are benign neoplasms. Deep fibromatoses, dermatofibrosarcoma protuberans, giant cell fibroblastoma, giant cell angiofibroma, hyalinizing spindle cell tumor with giant rosettes, solitary fibrous tumor, myxofibrosarcoma, low-grade fibromyxoid sarcoma, acral myxoinflammatory fibroblastic sarcoma, and classical fibrosarcoma, are malignant neoplasms, that is fibrosarcomas of variable malignant potential. Lesions dominated by myocytes/ myofibroblasts, e.g. cutaneous myofibroma/infantile myofibromatosis, or by macrophages, e.g. xanthogranulomas, are not part of this chapter. PMID:12079232

Zelger, Bernhard

2002-01-01

414

Integration of Computational Chemistry into the Chemistry Curriculum  

NASA Astrophysics Data System (ADS)

Computational chemistry has been integrated into the chemistry curriculum at the University of North Carolina at Wilmington by incorporating laboratory experiments into six existing undergraduate chemistry courses and adding one new course. This initiative was sponsored by an ILI grant from the National Science Foundation, which provided computers and software. The existing courses affected by the curricular change include Introduction to Computer Applications and Chemical Literature, Organic Chemistry I and II, Advanced Techniques of Organic Chemistry, Biochemical Techniques and Instrumentation, and Medicinal Chemistry. The new course that has been added is Structural Chemistry and Computational Methodology. Experiments are described which integrate the use of molecular modeling for prediction with verification by laboratory experiment. The unifying theme we utilized is to couple computational predictions with experimental results as much as possible. We have attempted to teach computational chemistry as one of a number of tools available to chemists, rather than a separate field of endeavor. Preliminary evaluation of this initiative indicates that students enjoy visualizing models of chemical structures and that the incorporation of computational chemistry into the curriculum has increased their interest in chemistry.

Martin, Ned H.

1998-02-01

415

Dense inhibitory connectivity in neocortex.  

PubMed

The connectivity diagram of neocortical circuits is still unknown, and there are conflicting data as to whether cortical neurons are wired specifically or not. To investigate the basic structure of cortical microcircuits, we use a two-photon photostimulation technique that enables the systematic mapping of synaptic connections with single-cell resolution. We map the inhibitory connectivity between upper layers somatostatin-positive GABAergic interneurons and pyramidal cells in mouse frontal cortex. Most, and sometimes all, inhibitory neurons are locally connected to every sampled pyramidal cell. This dense inhibitory connectivity is found at both young and mature developmental ages. Inhibitory innervation of neighboring pyramidal cells is similar, regardless of whether they are connected among themselves or not. We conclude that local inhibitory connectivity is promiscuous, does not form subnetworks, and can approach the theoretical limit of a completely connected synaptic matrix. PMID:21435562

Fino, Elodie; Yuste, Rafael

2011-03-24

416

Connectivity and Financial Network Shutdown  

Microsoft Academic Search

Connectivity is a measure of the number of connections in a network. It is applied here to financial network shutdown due to inter-institutional default. Since 1797 when Sir Francis Baring introduced the concept of ``lender of last resort\\

Laurence K. Eisenberg

1995-01-01

417

Bone and Connective Tissue Tumors  

MedlinePLUS

... Tumor (ATRT) Bone and Connective Tissue Brain Cysts Choroid Plexus Craniopharyngioma Ependymoma Germ Cell Glioblastoma Gliomas Hemangioma ... Tumor (ATRT) Bone and Connective Tissue Brain Cysts Choroid Plexus Craniopharyngioma Ependymoma Germ Cell Glioblastoma Gliomas Hemangioma ...

418

Organic Chemistry Animations  

NSDL National Science Digital Library

Students who might be puzzled by the world of organic chemistry will definitely want to bookmark this useful site created by a team of researchers at the University of Liverpool. The site focuses on providing interactive 3D animations for a number of important organic reactions that will be encountered by students taking organic chemistry. The site's homepage contains a list of recent updates and additions, and visitors will want to also look at the list of reactions covered on the left-hand side of the same page. After clicking on each reaction, visitors can view the animation and also click on the animation to view additional resources. For those who are looking for specific reactions, the site also contains an embedded search engine feature.

419

Nuclear analytical chemistry  

SciTech Connect

This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

Brune, D.; Forkman, B.; Persson, B.

1984-01-01

420

Aqueous chemistry of iodine  

SciTech Connect

The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H/sub 3/BO/sub 3/ at temperatures up to 150/sup 0/C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO/sub 3//sup -/ + 2I/sup -/ + 3H/sup +/, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >10/sup 4/ has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs.

Toth, L.M.; Pannell, K.D.; Kirkland, O.L.

1984-01-01

421

The World of Chemistry  

NSDL National Science Digital Library

One doesn't have to be a Glenn Seaborg or a Lord Ernest Rutherford to learn about chemistry, though it probably couldn't help to have some of their curiosity about the world of chemistry. Young chemists and their teachers will definitely benefit from this nice resource offered by the Annenberg Media project. This original video series was produced by the University of Maryland and the Educational Film Center, and it consists of 26 half-hour programs. With industrial and research chemists demonstrating a number of high-intensity experiments and processes, the series is quite a find. The installments include such titles as "Modeling the Unseen", "The Atom", and "The Busy Electron".

1990-01-01

422

Medicinal chemistry for 2020  

PubMed Central

Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein–protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists.

Satyanarayanajois, Seetharama D; Hill, Ronald A

2011-01-01

423

Fractal generalized zone plates.  

PubMed

The construction of fractal generalized zone plates from a set of periodic diffractive optical elements with circular symmetry is proposed. This allows us, for instance, to increase the number of foci of a conventional fractal zone plate while keeping the self-similarity property within the axial irradiance. The focusing properties of these fractal diffractive optical elements for points not only along but also in the close vicinity of the optical axis are investigated. In both cases analytical expressions for the irradiance are derived. Numerical simulations of the energetic efficiency of fractal generalized zone plates under plane wave illumination are carried out. In addition, some effects on the axial irradiance caused by variations in the area of their transparent rings are shown. PMID:19412233

Mendoza-Yero, Omel; Fernández-Alonso, Mercedes; Mínguez-Vega, Gladys; Lancis, Jesús; Climent, Vicent; Monsoriu, Juan A

2009-05-01

424

The Chemistry of Coffee  

NSDL National Science Digital Library

The paper Our Everyday Cup of Coffee: The Chemistry behind Its Magic by Marino Petracco provides a hearty blend of molecules for this month. The author deals with coffee at a number of different levels ranging from the economic and social to the still perplexing questions of flavor and aroma. The associated molecules demonstrate a range of structural features that students will benefit from examining in three dimensions.

425

Green chemistry: development trajectory  

NASA Astrophysics Data System (ADS)

Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references.

Moiseev, I. I.

2013-07-01

426

ADVANCED CHEMISTRY BASINS MODEL  

SciTech Connect

The advanced Chemistry Basin Model project has been operative for 48 months. During this period, about half the project tasks are on projected schedule. On average the project is somewhat behind schedule (90%). Unanticipated issues are causing model integration to take longer then scheduled, delaying final debugging and manual development. It is anticipated that a short extension will be required to fulfill all contract obligations.

William Goddard III; Lawrence Cathles III; Mario Blanco; Paul Manhardt; Peter Meulbroek; Yongchun Tang

2004-05-01

427

Life, Chemistry, Action!  

Microsoft Academic Search

\\u000a Born from clumps of Stardust spinning around a central sun, the planets of our Solar System, like most planets in the universe,\\u000a began their voyage through time with a rich mixture of chemistry and energy on board. From such a cauldron, life emerged on\\u000a our planet Earth early, and diversified into the great variety of living organisms that cover the

Louis Neal Irwin; Dirk Schulze-Makuch

428

Advanced Chemistry Basins Model  

SciTech Connect

The DOE-funded Advanced Chemistry Basin model project is intended to develop a public domain, user-friendly basin modeling software under PC or low end workstation environment that predicts hydrocarbon generation, expulsion, migration and chemistry. The main features of the software are that it will: (1) afford users the most flexible way to choose or enter kinetic parameters for different maturity indicators; (2) afford users the most flexible way to choose or enter compositional kinetic parameters to predict hydrocarbon composition (e.g., gas/oil ratio (GOR), wax content, API gravity, etc.) at different kerogen maturities; (3) calculate the chemistry, fluxes and physical properties of all hydrocarbon phases (gas, liquid and solid) along the primary and secondary migration pathways of the basin and predict the location and intensity of phase fractionation, mixing, gas washing, etc.; and (4) predict the location and intensity of de-asphaltene processes. The project has be operative for 36 months, and is on schedule for a successful completion at the end of FY 2003.

William Goddard; Mario Blanco; Lawrence Cathles; Paul Manhardt; Peter Meulbroek; Yongchun Tang

2002-11-10

429

Snow chemistry across Antarctica  

NASA Astrophysics Data System (ADS)

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO3, SO4) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of Antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http://www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized.

Bertler, N.; Mayewski, P. A.; Aristarain, A.; Barrett, P.; Becagli, S.; Bernardo, R.; Bo, S.; Xiao, C.; Curran, M.; Qin, D.; Dixon, D.; Ferron, F.; Fischer, H.; Frey, M.; Frezzotti, M.; Fundel, F.; Genthon, C.; Gragnani, R.; Hamilton, G.; Handley, M.; Hong, S.; Isaksson, E.; Kang, J.; Ren, J.; Kamiyama, K.; Kanamori, S.; Kärkäs, E.; Karlöf, L.; Kaspari, S.; Kreutz, K.; Kurbatov, A.; Meyerson, E.; Ming, Y.; Zhang, M.; Motoyama, H.; Mulvaney, R.; Oerter, H.; Osterberg, E.; Proposito, M.; Pyne, A.; Ruth, U.; Simões, J.; Smith, B.; Sneed, S.; Teinilä, K.; Traufetter, F.; Udisti, R.; Virkkula, A.; Watanabe, O.; Williamson, B.; Winther, J.-G.; Li, Y.; Wolff, E.; Li, Z.; Zielinski, A.

430

Chemistry Learning Tools  

NSDL National Science Digital Library

This site contains a large number of animated tutorials to help visualize how to determine the Lewis Structure of more than 60 molecules, how to interpret the Lewis structure in terms of valence shell electron pair repulsion (VSEPR) theory and how to interpret the Lewis structure in terms of valence bond (VB) theory. Another set of tutorials provides animated organic reaction mechanisms (ORM) to help visualize more than 50 common organic reactions and concepts. The Director Shockwave Player (plug-in) from Macromedia is required. The site also provides "Mastering Chemistry" which contains more than 60 automated assessment units with multiple topics that address the content treated in college introductory and general chemistry as well as high school chemistry. Students always are presented a unique set of questions each time they do a unit. Hence they can repeat the unit as many times as necessary to master the material. The Authorware Web Player (plug-in) and a special set of fonts (ChemSyn) are required in order to display and conveniently type superscripts and subscripts.

431

Chemistry and cosmology.  

PubMed

The simplest elements, hydrogen and helium, offer a remarkably rich chemistry, which has controlled crucial features of the early evolution of the universe. Theoretical models of the origin of structure (stars, galaxies, clusters of galaxies, etc.) now incorporate this chemistry in some detail. In addition to the origin of structure, cosmologists are concerned with observational tests of competing world models. Primordial chemistry may give rise to some of the earliest departures from thermodynamic equilibrium in the universe. These effects may be observable as broad-band spectroscopic distortions of the cosmic background radiation, which otherwise exhibits a nearly perfect blackbody spectrum. The chemical history of the expanding universe is followed through a detailed calculation of the evolution of the abundances of H, H+, H-, H2, H2+, H3+, and other minor species. It is shown that continuous absorption by the small concentration of H- can produce a distortion in the cosmic background spectrum with a maximum at a frequency near nu/c = 9 cm-1 (wavelength 1.1 mm). The predicted effect lies only a factor of 5 below current limits. Its detection would provide an important test of our understanding of the recombination epoch of the universe. PMID:17191439

Black, John H

2006-01-01

432

A note on symmetric connections  

NASA Astrophysics Data System (ADS)

In this paper we analyze a reciprocal of the fundamental theorem of Riemannian geometry. We give a condition for a symmetric connection to be locally the Levi-Civita connection of a metric. We also construct a couple of natural examples of connections on the n-dimensional torus and investigate the global problem.

Cocos, M.

2006-03-01

433

Nuclear free zone  

SciTech Connect

Health professionals have played a leading role in alerting and educating the public regarding the danger of nuclear war which has been described as the last epidemic our civilization will know. Having convinced most people that the use of nuclear weapons would mean intolerable consequences, groups such as Physicians for Social Responsibility have focused on the second critical question how likely is it that these weapons will be used. The oultlook is grim. This article describes the nuclear free zone movement, explores relevant legal questions, and shows how the political potential of nuclear free zones threatens to open a deep rift in the American constitutional system.

Christoffel, T.

1987-07-01

434

Fractional spiral zone plates.  

PubMed

In this paper, we generalize the concept of classical spiral zone plates (SZPs) to fractional spiral zone plates (FSZPs). By using an SZP with a fractional topological charge and controlling the starting orientation, we can break down the symmetry of the focusing process to give orientation-selective anisotropic vortex foci. Numerical results show that its binary structure gives additional high-order foci on the optical axis and the intensities in the foci can be controlled by properly choosing the fractional topological charge. Our study reveals the feasibility to control the intensity in the foci by means of FSZPs. PMID:23456058

Wei, Lai; Gao, Yulin; Wen, Xianlun; Zhao, Zongqing; Cao, Leifeng; Gu, Yuqiu

2013-02-01

435

Use of oxygen-free refractories in the tuyere zones of converters  

Microsoft Academic Search

New forms of oxygen converter production of steel introduced in the USSR (bottom and combined blowing, etc.) have been restrained by the absence of highly resistant refractories for use in the tuyere zones of a converter bottom. In connection with this to increase the life of the tuyere zones various materials prepared based on highly refractory oxides have been tested

A. S. Freidenberg; G. I. Fugman; V. A. Perepelitsyn; G. I. Bad'in; A. A. Vyatkin; P. I. Zolkin

1985-01-01

436

New data on the fine structural organization of the subsynaptic zone of the nerve cell  

Microsoft Academic Search

The fine structural organization of the subsynaptic zone of the nerve cell was studied by electron microscopy. This zone of the neuron was shown to be directly connected with special intracellular organelles or microtubules. Their peripheral ends, expanded like funnels, are in close contact with the postsynaptic membrane and apparently merge with its inner osmiophilic layer. These observations definitely show

A. A. Milokhin

1977-01-01

437

Groundwater chemistry at Yucca Mountain, Nevada, and vicinity  

SciTech Connect

The chemistry of groundwater at Yucca Mountain and vicinity has been reviewed and compared with the chemistry of water from the Nevada Test Site and surrounding areas such as the Amargosa Desert and Oasis Valley. Sodium is the primary cation and carbonate is the primary anion in water from the saturated zone of the tuffaceous aquifer at Yucca Mountain. Other major cations present are calcium, potassium, and magnesium; other major anions are sulfate and chloride, with lesser quantities of fluoride and nitrate. Aqueous silica is also present. The primary purpose of this review was to survey water-composition data and look for relations among the compositional variables that could provide insight into the processes that control the composition and would ultimately affect radionuclide transport. The following conclusions were inferred from the review. Major cation concentrations are controlled by rock dissolution and mineral precipitation reactions as well as by cation exchange with existing minerals. Aqueous carbonate initially comes from atmospheric and soil-zone carbon dioxide, but there is evidence at Yucca Mountain that carbon dioxide in the gas phase of the unsaturated zone supplies additional carbonate to saturated-zone water in the tuffaceous aquifer as mineral dissolution and precipitation reactions raise the pH of the water. This combination is effectively mineral dissolution and precipitation in a system that is open with respect to carbon dioxide. A carbon model for this process is discussed.

Kerrisk, J.F.

1987-02-01

438

Power converter connection configuration  

DOEpatents

EMI shielding is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

Beihoff, Bruce C. (Wauwatosa, WI); Kehl, Dennis L. (Milwaukee, WI); Gettelfinger, Lee A. (Brown Deer, WI); Kaishian, Steven C. (Milwaukee, WI); Phillips, Mark G. (Brookfield, WI); Radosevich, Lawrence D. (Muskego, WI)

2008-11-11

439

Editorial: Au Courant Connections  

NSDL National Science Digital Library

In an effort to connect with college-level science instructors "beyond the classroom walls," the editor plans to start a blog. Blogs are the electronic equivalent of an open conversation at a relaxed conference. You get there through an internet site, and watch what's going on. Because it's a place for an ongoing discussion, you can chime in at any time just by typing a casual sentence. Entries by everyone are usually brief, frequently direct, and don't require more than a modicum of energy to overcome the natural inertia or shyness we all experience. So fire up your browser, copy this address into the appropriate spot--http://blogs.nsta.org/JCSTBlog, and hit "enter." We're all waiting!

Cutler, Ann

2009-03-01

440

"F-The French Connection."  

ERIC Educational Resources Information Center

Provides background information for teachers on the chemistry of flourine. Points out that it links aerosols with refrigerants, anaesthetics with fire-fighting agents, batteries with blood substitutes, and atomic energy with the steel, petroleum, and aluminum industries. (JN)

Sleigh, John; Plevey, Ray

1986-01-01

441

49 CFR 71.8 - Mountain zone.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Mountain zone. 71.8 Section 71.8 Transportation... STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part...

2011-10-01

442

49 CFR 71.8 - Mountain zone.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Mountain zone. 71.8 Section 71.8 Transportation... STANDARD TIME ZONE BOUNDARIES § 71.8 Mountain zone. The fourth zone, the mountain standard time zone, includes that part...

2012-10-01

443

Connecting assembly and method  

SciTech Connect

Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The buoyancy of the assembly is selectively controlled by selectively controlling the quantity and density of fluid in the area between the tubes. In an embodiment shown, a marine drilling facility is joined to an underwater well site by a riser with a liner set and sealed therein, and gas-lift pumping is used in controlling buoyancy. In a method, a riser is set between an underwater well site and a marine well operating facility. A first segment of the well may be drilled through the riser. Casing is cemented in the well, and a liner is sealed at its bottom end to the riser. Air and jet lines are positioned in the area between the liner and the riser to control the density and quantity of fluid in that area. Continued drilling may occur through the liner and the casing. The connecting assembly may also be constructed by extending a first tube between two locations and generally enclosing a second which is anchored to the riser toward both ends and held in tension. In a method, a riser is set. Then, a liner is positioned within the riser, and anchored to the riser near the bottom of the liner. The liner is then pulled up on relative to the riser, and anchored at the top to hold the liner in tension and to prevent it from slipping downwardly relative to the riser.

Wardlaw, H. W.

1980-08-12

444

Chemistry and narrative: Short stories and school chemistry  

Microsoft Academic Search

Science competitions can provide rich sources of data about students' knowledge and attitudes. The Australian National Chemistry\\u000a Week's Short Story Competition generates a large number of fictional narratives that can be analysed for the authors' views\\u000a of the place and relevance of chemistry in their lives, as well as providing an opportunity to integrate chemistry knowledge\\u000a with their writing skills.

Paul Strube

1996-01-01

445

Integrated Critical Zone project  

NSDL National Science Digital Library

This project is a way to assemble information about geology, hydrogeology, and soils into a coherent whole in a way that may otherwise not happen in any one class. The "critical zone" concept ties the pieces together. This project is not tied to a course but I have used it as a component of a senior assessment for geology students.

Bader, Nick

446

ZONE PURIFICATION OF BERYLLIUM  

Microsoft Academic Search

Preliminary experimental evidence is presented to show that the metallic ; impurities aluminum, iron, silicon, and beryllium oxide, as found in commercially ; pure hotpressed beryllium pewder, can be reduced to lower concentrations by zone-; purification techniques. The reduction in the concentration of aluminum to ; extremely low levels (10 ppm) is noteworthy, since earlier work demonstrated that ; aluminum

W. R. Mitchell; J. A. Mullendore; R. S. Maloof

1961-01-01

447

euro zone crisis 2010  

Microsoft Academic Search

The euro zone crisis is commonly regarded as a sovereign debt crisis. This definition certainly applies to Greece, but the Irish case represents an almost pure specimen of a banking crisis voluntarily transformed into a sovereign crisis. A debt crisis in two small, peripheral economies could become systemic because the financial system of the euro area is overstretched and highly

Daniel Gros; Cinzia Alcidi

448

New Madrid Seismic Zone.  

National Technical Information Service (NTIS)

The New Madrid Seismic Zone is one of the most potentially dangerous natural hazards that exists anywhere in the continental United States. Having produced three of the greatest earthquakes known to man over a 60-day period during the winter of 1811-1812,...

J. D. Norwood

1998-01-01

449

Deformation Zone Analysis  

NSDL National Science Digital Library

The quick analysis of deformation zones provides an overview of system-relative atmospheric circulations. Since deformation is a primary factor in frontogenesis and frontolysis, understanding of these system-relative circulations is crucial to the diagnosis of atmospheric processes and weather prediction.

Spangler, Tim

2007-03-22

450

Combating splash zone corrosion  

Microsoft Academic Search

Corrosion protection offshore steel structure in the near-surface sea splash zone is examined. It was found that Monel 400 sheathing offers protection to offshore structures. Service experience to date and the most relevant laboratory and field trial data qualitatively indicate that a sheathing of Monel alloy 400 provides excellent protection to offshore hot oil riser pipes against corrosion in the

Glover

1977-01-01

451

Chemistry and narrative: Short stories and school chemistry  

NASA Astrophysics Data System (ADS)

Science competitions can provide rich sources of data about students' knowledge and attitudes. The Australian National Chemistry Week's Short Story Competition generates a large number of fictional narratives that can be analysed for the authors' views of the place and relevance of chemistry in their lives, as well as providing an opportunity to integrate chemistry knowledge with their writing skills. This paper reports on the purposes of the competition, responses in terms of the short stories received and discusses some of the educational implications for the use of stories in the chemistry classroom.

Strube, Paul

1996-06-01

452

NeoModus: Direct Connect  

NSDL National Science Digital Library

Direct Connect is an online file-sharing community. The important feature in Direct Connect is that there is no main data center or master server. The users themselves provide the network architecture. Direct Connect software has two modules - the client and the hub. You can use the Direct Connect client to download files from other users in the Direct Connect network. The hub allows you to share multiple directories from your local and mapped directories with other users. Direct Connect has a user-friendly interface which provides integrated searching, graphical navigation of files, and public and private chatting. It can also be set to shut down automatically after all transfers have been completed. Direct Connect client and hub are available for download from the site. Please note that this program is advertiser supported and some non-personally identifiable information is collected. Concerned users should consult the site's privacy policy.

453

Future perspectives of radiation chemistry  

NASA Astrophysics Data System (ADS)

Future perspectives of radiation chemistry are discussed by the analysis of the related information in detail as obtained from our recent surveys of publications and scientific meetings in radiation chemistry and its neighboring research fields, giving some examples, and are summarized as follows. (1) Traditionally important core-parts of radiation chemistry should be activated more. The corresponding research programs are listed in detail. (2) Research fields of physics, chemistry, biology, medicine, and technology in radiation research should interact more among them with each other. (3) Basic research of radiation chemistry should interact more with its applied research. (4) Interface research fields with radiation chemistry should be produced more with mutually common viewpoints and research interests between the two. Interfaces are not only applied research but also basic one.

Hatano, Yoshihiko

2009-12-01

454

Directed differential connectivity graph of interictal epileptiform discharges  

PubMed Central

In this paper, we study temporal couplings between interictal events of spatially remote regions in order to localize the leading epileptic regions from intracerebral electroencephalogram (iEEG). We aim to assess whether quantitative epileptic graph analysis during interictal period may be helpful to predict the seizure onset zone of ictal iEEG. Using wavelet transform, cross-correlation coefficient, and multiple hypothesis test, we propose a differential connectivity graph (DCG) to represent the connections that change significantly between epileptic and non-epileptic states as defined by the interictal events. Post-processings based on mutual information and multi-objective optimization are proposed to localize the leading epileptic regions through DCG. The suggested approach is applied on iEEG recordings of five patients suffering from focal epilepsy. Quantitative comparisons of the proposed epileptic regions within ictal onset zones detected by visual inspection and using electrically stimulated seizures, reveal good performance of the present method.

Amini, Ladan; Jutten, Christian; Achard, Sophie; David, Olivier; Soltanian-Zadeh, Hamid; Hossein-Zadeh, Gh. Ali; Kahane, Philippe; Minotti, Lorella; Vercueil, Laurent

2011-01-01

455

Directed differential connectivity graph of interictal epileptiform discharges.  

PubMed

In this paper, we study temporal couplings between interictal events of spatially remote regions in order to localize the leading epileptic regions from intracerebral EEG (iEEG). We aim to assess whether quantitative epileptic graph analysis during interictal period may be helpful to predict the seizure onset zone of ictal iEEG. Using wavelet transform, cross-correlation coefficient, and multiple hypothesis test, we propose a differential connectivity graph (DCG) to represent the connections that change significantly between epileptic and nonepileptic states as defined by the interictal events. Postprocessings based on mutual information and multiobjective optimization are proposed to localize the leading epileptic regions through DCG. The suggested approach is applied on iEEG recordings of five patients suffering from focal epilepsy. Quantitative comparisons of the proposed epileptic regions within ictal onset zones detected by visual inspection and using electrically stimulated seizures, reveal good performance of the present method. PMID:21156385

Amini, L; Jutten, C; Achard, S; David, O; Soltanian-Zadeh, H; Hossein-Zadeh, G A; Kahane, P; Minotti, L; Vercueil, L

2010-12-13

456

Volume strain, strain type and flow path in a narrow shear zone  

NASA Astrophysics Data System (ADS)

This study explores the state of finite strain and changes in the mean kinematic vorticity number, grain size, whole-rock chemistry and mineralogy across an upper amphibolite-facies shear zone in a metadiorite, northern Malawi, east-central Africa. P-T conditions during shear-zone formation and deformation were approximately 700-750°C and 5-7kbar and are slightly less than P-T conditions for the regional peak of metamorphism. The major rock-forming minerals, plagioclase, hornblende, biotite, and quartz, were deformed by crystal-plastic processes accompanied by, except for hornblende, dynamic recrystallization. The modal abundance of all four major rock-forming minerals shows no systematic change from the country rock into and across the shear zone, indicating that shear-zone development was not associated with retrograde mineral reactions. The grain size of the major rock-forming minerals decreases within the shear zone. Plagioclase and hornblende, which occur as porphyroblasts outside the shear zone, exhibit a bimodal grain-size distribution within the shear zone. Quartz has a unimodal grain-size distribution in the shear zone. Major and trace element chemistry does not change systematically across the shear zone, implying no volume change in the mylonite. Matrix strain data for plagioclase and hornblende by the Fry method and fabric strain as deduced from Rf/? analysis of plagioclase and quartz grains demonstrate a slightly constrictional strain type (K 1.5) across the shear zone. The quantitative finite-strain data for the different residual minerals as obtained by unlike methods show no systematic variation, but recrystallized plagioclase grains record higher strain than the residual grains. The mean kinematic vorticity number changes from approximately 0.3 outside to approximately 0.8 within the shear zone, indicating that the bulk deformation path deviated from progressive simple shear. The estimates for finite strain and the degree of noncoaxiality account for approximately 50% of thinning normal to the shear zone.

Ring, U.

457

Monitoring and data analysis for the Vadose Zone Monitoring System (VZMS), McClellan AFB. Quarterly status report, August 15, 1997--November 15, 1997  

SciTech Connect

This report contains information on field and laboratory work performed between August 15th and November 15th at site S-7 in IC 34, at McClellan AFB. At this location, a Vadose Zone Monitoring System (VZMS) (LBNL, 1996) is currently being used to collect subsurface data including hydraulic potential, soil gas pressure, moisture content, water chemistry, gas chemistry, and temperature.

Zawislanski, P.T.; Mountford, H.S.; Dahlquist, R.; Rodriguez, S.J.; Salve, R.

1997-12-05

458

NUCLEAR CHEMISTRY ANNUAL REPORT 1970  

SciTech Connect

Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

Authors, Various

1971-05-01

459

The SOHO-Stellar Connection  

NASA Astrophysics Data System (ADS)

The `solar-stellar connection' bridges the daytime and nighttime communities; an essential link between the singular, but detailed, views of our Sun, and the broad, but coarse, glimpses of the distant stars. One area in particular - magnetic activity - has profited greatly from the two way traffic in ideas. In that spirit, I present an evolutionary context for coronal activity, focusing on the very different circumstances of low-mass main-sequence stars like the Sun, compared with more massive stars. The former are active mainly very early in their lives, whereas the latter become coronal only near the end of theirs, during the brief incursion into the cool half of the Hertzsprung-Russell diagram as yellow, then red, giants. I describe tools at the disposal of the stellar astronomer; especially spectroscopy in the ultraviolet and X-ray bands where coronae leave their most obvious imprints. I compare HST STIS spectra of solar-type dwarfs - ? Dor (F7 V), an active coronal source, and ? Cen A (G2 V), near twin of the Sun - to the SOHO SUMER UV solar atlas. I also compare the STIS line profiles of the active coronal dwarf to the corresponding features in the mixed activity `hybrid chromosphere' bright giant ? TrA (K2 II) and the archetype `non-coronal' red giant Arcturus (? Boo K2 III). The latter shows dramatic evidence for a `cool absorber' in its outer atmosphere that is extinguishing the `hot lines' (like Siiv ?1393 and Nv ?1238) below about 1500 Å the corona of the red giant seems to lie beneath its extended chromosphere, rather than outside as in the Sun. I present an early taste of the moderate resolution spectra we can expect from the recently launched Chandra X-ray Observatory (CXO), and contemporaneous STIS high resolution UV measurements of the CXO calibration star Capella (? Aur G8 III + G1 III). Last, I describe preliminary results from a May 1999 observing campaign involving SOHO SUMER, TRACE, and the Kitt Peak Infrared Imaging Spectrometer (IRIS). The purpose was to explore the dynamics of the quiet solar atmosphere through the key `magnetic transition zone' that separates the kinetically dominated deep photosphere from the magnetically dominated coronal regime. Linking spatially and temporally resolved solar phenomena to properties of the average line shapes (widths, asymmetries, intensity ratios, and Doppler shifts) is a crucial step in carrying physical insights from the solar setting to the realm of the distant stars.

Ayres, Thomas R.

2000-04-01

460

Top 20 Activities in Chemistry  

NSDL National Science Digital Library

At this website, Quia furnishes 20 interactive activities to educate students about chemistry. Students can play matching, word, and concentration games to learn the names and formulas of binary ionic compounds, element symbols, common names of chemicals, and other basic chemistry concepts. The website also offers a quiz about chemical bonds, a chemistry Jeopardy game, a Battleship game about balancing equations, and much more. While users can subscribe to customize the activities, the free activities supplied at the website offer amusing ways to learn about chemistry.

461

American Association for Clinical Chemistry  

MedlinePLUS

American Association for Clinical Chemistry Better health through laboratory medicine Home | Customer Service | Site Map | Cart | Login About AACC Members Events Government & Public Affairs Resource ...

462

Brookhaven National Laboratory: Chemistry Department  

NSDL National Science Digital Library

At this website, the Brookhaven National Laboratory presents its chemistry research dealing primarily with imaging and neuroscience, charge transfer for energy conversion, chemistry with ionizing radiation, catalysis and surface science, nanoscience, combustion, and nuclear chemistry. Within each category, users can find instructive text and supportive images about the specific projects and the leading researchers. Visitors can learn about the Beamline U7A at the National Synchrotron Light Source, the Laser-Electron Accelerator Facility (LEAF), the Positron Emission Tomography (PET) Facility, and other exceptional research facilities. The website features histories of the chemistry department and of the Brookhaven National Laboratory.

463

The SOHO-Stellar Connection  

NASA Astrophysics Data System (ADS)

I discusses practical aspects of the so-called "solar-stellar" connection; namely, the fundamental principles, the tools at the disposal of the stellar astronomer, and a few recent examples of the connection in action. I provide an overall evolutionary context for coronal activity, calling attention to the very different circumstances of low mass main sequence stars like the Sun, which are active mainly early in their lives; compared with more massive stars, whose coronally active phase occurs near the end of their lives, during their brief incursion into the cool half of the Hertzsprung-Russell diagram as yellow and then red giants. On the instrumental slide, I concentrate primarily on spectroscopy, in the ultraviolet and X-ray bands where coronae leave their most obvious signatures. I present an early glimpse of the type of moderate resolution spectra we can expect from the recently launched Chandra observatory, and contemporaneous HST STIS high-resolution UV measurements of the CXO calibration star Capella (alpha Aur; G8 III + G1 III). I compare STIS spectra of solar-type dwarfs-zeta Dor (F7 V), an active coronal source; and alpha Cen A (G2 V), a near twin of the Sun-to a trace obtained with the SOHO SUMER imaging UV spectrometer. I also compare STIS line profiles of the active coronal dwarf to the corresponding features in the mixed-activity "hybrid-chromosphere" bright giant alpha TrA (K2 II) and the archetype "noncoronal" red giant Arcturus (alpha Boo; K2 III). The latter shows dramatic evidence for a "cool absorber" in its outer atmosphere that is extinguishing the "hot lines" (like Si IV lambda1393 and N V lambda1238) below about 1500 A, probably through absorption in the Si I lambda1525 and C I lambda1240 photoionization continua. The disappearance of coronae across the "Linsky-Haisch" dividing line near K1 III thus apparently is promoted by a dramatic overturning in the outer atmospheric structure, namely the coronae of the red giants seem to lie beneath their extended chromospheres, rather than outside as in the Sun. I then discuss an intriguing long-slit STIS low-resolution observation of an X-ray active late-A dwarf in the nearby Hyades cluster: the spatially resolved UV spectroscopy clearly shows that a previously unseen close companion (a dKe or dMe) likely is responsible for the coronal activity, rather than some unexplained departure of the A dwarf from its expected state of X-ray dormancy. Finally, I describe early results from a joint observing campaign involving SOHO SUMER, TRACE, and the Kitt Peak Infrared Imaging Spectrometer, conducted May 1999, to explore the dynamics of the quiet solar atmosphere through the key "magnetic transition zone" that separates the kinetically dominated deep photosphere from the magnetically dominated coronal regime. Linking spatially and temporally resolved solar properties to aspects of the averaged lineshapes (for example: widths, asymmetries, intensity ratios, and Doppler shifts) is a crucial step in carrying any physical wisdom we develop in the solar setting to the distant stars.

Ayres, Thomas R.

1999-01-01

464

Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories. The Pinacol Rearrangement: An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories  

Microsoft Academic Search

This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation---a new technique for the general chemistry students and a basic one for the organic students---to isolate

Caleb A. Arrington; Jameica B. Hill; Ramin Radfar; David M. Whisnant; Charles G. Bass

2008-01-01

465

Extended Wordsearches in Chemistry  

NASA Astrophysics Data System (ADS)

Students can be encouraged to develop their factual knowledge by use of puzzles. One strategy described here is the extended wordsearch, where the wordsearch element generates a number of words or phrases from which the answers to a series of questions are selected. The wordsearch can be generated with the aid of computer programs, though in order to make them suitable for students with dyslexia or other learning difficulties, a simpler form is more appropriate. These problems can be employed in a variety of contexts, for example, as topic tests and classroom end-of-lesson fillers. An example is provided in the area of calcium chemistry. Sources of suitable software are listed.

Cotton, Simon

1998-04-01

466

The Virtual Chemistry Laboratory  

NSDL National Science Digital Library

This networked laboratory simulation provides an environment in which students can select from hundreds of standard chemical reagants and combine them in any way they see fit. Instructors may use this environment in a variety of settings including student homework, group projects, computer lab activities and pre- and post-lab exercises to support varied approaches to chemical education. Activities are stored in our online homework repository which currently includes: acids and bases, chemical equilibrium, molarity, redox chemistry, solubility, stoichiometry, thermochemistry, and quantitative analysis.

Yaron, David

1999-01-01

467

Korean Kimchi Chemistry  

NSDL National Science Digital Library

Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious a

Murfin, Brian

2009-10-01

468

The Chitin Connection  

PubMed Central

ABSTRACT Chitin, a polymer of N-acetylglucosamine, is an essential component of the fungal cell wall. Chitosan, a deacetylated form of chitin, is also important in maintaining cell wall integrity and is essential for Cryptococcus neoformans virulence. In their article, Gilbert et al. [N. M. Gilbert, L. G. Baker, C. A. Specht, and J. K. Lodge, mBio 3(1):e00007-12, 2012] demonstrate that the enzyme responsible for chitosan synthesis, chitin deacetylase (CDA), is differentially attached to the cell membrane and wall. Bioactivity is localized to the cell membrane, where it is covalently linked via a glycosylphosphatidylinositol (GPI) anchor. Findings from this study significantly enhance our understanding of cryptococcal cell wall biology. Besides the role of chitin in supporting structural stability, chitin and host enzymes with chitinase activity have an important role in host defense and modifying the inflammatory response. Thus, chitin appears to provide a link between the fungus and host that involves both innate and adaptive immune responses. Recently, there has been increased attention to the role of chitinases in the pathogenesis of allergic inflammation, especially asthma. We review these findings and explore the possible connection between fungal infections, the induction of chitinases, and asthma.

Goldman, David L.; Vicencio, Alfin G.

2012-01-01

469

An example of inversion in a brittle shear zone  

NASA Astrophysics Data System (ADS)

A useful tool to document structural inversion inside a shear zone is the identification of overprinted structures, which can increase the complexity of the internal fabric of shear zones. In the case of thrust faults, shear zones can also be problematic due to the occurrence of structures connected to flexural slip along bedding in the recumbent forelimb. Therefore identification of superimposition among different structures can help to distinguish among these configurations inside a shear zone. In Central Apennines (Italy), favourable conditions along the outcrop of Mt. Tancia's thrust allowed the discovery of two sets of superimposed fabric elements referring to two opposite senses of shear. The first is related to thrusting (top-to-E NE), whereas the second is likely associated to reactivation in normal sense (top-to-W SW). The fabric elements have been mapped and their distribution inside a semi-brittle shear zone has been defined. High angle extensional shear planes occurring only in the uppermost part of the shear zone (closest to the main thrust plane) have been interpreted as a new generation of C-planes, connected to negative reactivation, instead of Riedel shear planes. The overprinting relationship defined inside the shear zone helps in discriminating whether the observed structures developed in the footwall of the main thrust or on the recumbent limb of the hanging wall's anticline. The deformation inside the shear zone can be described using a simple shear model at the outcrop scale, where reoccurrence of fibrous calcite on shear C-planes should control rotation of S-planes; these are dissolution planes parallel to the XY-plane of the local strain ellipsoid. At thin section scale, instead, veins maintaining the same orientation suggest a coaxial deformation due to repeated crystallization events controlled by fluid pressure and differential stress variation.

Bigi, S.

2006-03-01

470

The University of Liverpool: Research Activities in the Department of Chemistry  

NSDL National Science Digital Library

At this website, the Chemistry Department at the University of Liverpool presents its research in organic, inorganic, materials, physical, surfaces, and catalysis chemistry. The site furnishes links to over 35 faculty member homepages where users can learn about individual research interests and successes through concise descriptions and instructive figures. The Surface Science Research Centre link provides an image gallery and highlights of research projects such as _Chirality in Two-Dimensions_ and _Rare-Earth Metal Surfaces_. Through the materials provided in the Centre for Nanoscale Science and additional links, visitors can discover the research connections of the chemistry department and other departments including the Life Sciences.

471

Organic Chemistry on Titan Versus Terrestrial Prebiotic Chemistry: Exobiological Implications.  

National Technical Information Service (NTIS)

Current thinking on the origins of life on Earth are reviewed and the plausible impact of the study of Titan chemistry on this field is discussed. On the primitive Earth, in the presence of liquid water, prebiotic organic chemistry starting from simple re...

F. Raulin C. Frere L. Do M. Khlifi P. Paillous

1992-01-01

472

Introducing Chemistry Students to the "Real World" of Chemistry  

ERIC Educational Resources Information Center

|A majority of chemistry graduates seek employment in a rapidly changing chemical industry. Our attempts to provide the graduates with skills in entrepreneurship and the ability to understand and communicate with their chemical engineering colleagues, in addition to their fundamental knowledge of chemistry, are described. This is done at…

Brown, Michael E.; Cosser, Ronald C.; Davies-Coleman, Michael T.; Kaye, Perry T.; Klein, Rosalyn; Lamprecht, Emmanuel; Lobb, Kevin; Nyokong, Tebello; Sewry, Joyce D.; Tshentu, Zenixole R.; van der Zeyde, Tino; Watkins, Gareth M.

2010-01-01

473

Networked Instructional Chemistry: Using Technology To Teach Chemistry  

Microsoft Academic Search

Networked multimedia microcomputers provide new ways to help students learn chemistry and to help instructors manage the learning environment. This technology is used to replace some traditional laboratory work, collect on-line experimental data, enhance lectures and quiz sections with multimedia presentations, provide prelaboratory training for beginning nonchemistry- major organic laboratory, provide electronic homework for organic chemistry students, give graduate students

Stanley Smith; Iris Stovall

1996-01-01

474

Art in Chemistry: Chemistry in Art. Second Edition  

ERIC Educational Resources Information Center

This textbook integrates chemistry and art with hands-on activities and fascinating demonstrations that enable students to see and understand how the science of chemistry is involved in the creation of art. It investigates such topics as color integrated with electromagnetic radiation, atoms, and ions; paints integrated with classes of matter,…

Greenberg, Barbara R.; Patterson, Dianne

2008-01-01

475

Art in Chemistry: Chemistry in Art. Second Edition  

ERIC Educational Resources Information Center

|This textbook integrates chemistry and art with hands-on activities and fascinating demonstrations that enable students to see and understand how the science of chemistry is involved in the creation of art. It investigates such topics as color integrated with electromagnetic radiation, atoms, and ions; paints integrated with classes of matter,…

Greenberg, Barbara R.; Patterson, Dianne

2008-01-01

476

Aeration Zone Symposium  

NASA Astrophysics Data System (ADS)

The International Symposium on Recent Investigations in the Zone of Aeration (RIZA) was organized by the Institute for Hydrogeology and Hydrochemistry of the Technical University of Munich and held October 1-5, 1984, in the lecture halls of the Grosshadern Klinik in Munich, Federal Republic of Germany (FRG). P. Udluft, B. Merkel, and K.-H. Prüsl, all of the university, were responsible for the organization of the symposium, which was under the patronage of K.-E. Quentin. There were over 200 participants from 22 different countries, among them Australia, Canada, China, India, and the United States. The topics of the symposium were the physical, chemical, and microbiological processes in the unsaturated zone, the region between the surface and the groundwater level. Here a number of complex processes occur that on the one hand are of natural origin and on the other hand are influenced by human activities in a number of ways.

Merkel, B.

477

The Galactic Habitable Zone  

SciTech Connect

We propose the concept of a 'Galactic Habitable Zone' (GHZ). Similar to the circumstellar habitable zone (CHZ), the GHZ is that region in a spiral galaxy where life can exist. The width of the GHZ is controlled by two factors. The inner (closest to the center of the galaxy) limit is set by threats to complex life: nearby transient sources of ionizing radiation and comet impacts. Such threats tend to increase close to the galactic center. The outer limit is imposed by galactic chemical evolution, specifically the abundance of heavier elements. Observation of stars in the Milky Way galaxy suggests that the outer reaches of a spiral galaxy may be too poor in heavy elements to allow terrestrial complex life to exist.

Gonzalez, Guillermo (Iowa State University)

2002-08-21

478

MindZone  

NSDL National Science Digital Library

As incidences of mental health problems among teenagers increase, it is important to make the general public aware of what resources are available to help these individuals (and those who care about them) with such issues. The MindZone site is sponsored by the Annenberg Foundation Trust at Sunnylands with support from the Annenberg Public Policy of the University of Pennsylvania. The site itself is divided into three separate sections: Cope, Care, and Deal. Within each section, users can take quizzes about mental health and learn about how to explore the feelings associated with depressions, suicide, and a number of other conditions. In the MindZone Machine area, users can learn about different anxiety orders and get answers to frequently asked questions. Finally, the site is rounded out by an Ask the Expert area, where visitors can find thoughtful responses to such queries as: "Do people with schizophrenia have multiple personalities?".

2004-01-01

479

49 CFR Horns - Quiet Zones  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Quiet Zones Horns Silenced Horns...Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...quiet zone? (a) A railroad operating over...Groups of CrossingsâQuiet...

2010-10-01

480

Microstructure of shear zones in granular rock  

NASA Astrophysics Data System (ADS)

On the basis of image analysis, porosity and grain-size changes have been studied inside the shear bands formed in triaxial testing on a Fontainebleau sandstone with initial porosity of 21% under drained and undrained conditions. In drained conditions, it is obtained that for specimens tested under relatively low confining pressure (7 MPa), the porosity reaches a maximal value of about 30% inside the band and decreases rapidly towards the initial value of 21% outside the band. This is interpreted as dilating shear banding at low confining pressure. For specimens tested under relatively high confining pressure (28 MPa), a different patterning is observed. A compacting zone with high grain crushing and low porosity (values between 2 and 19%) is observed in the center of the band. This zone is surrounded by a dilating one with grain cracking and high porosity (up to 36%). These two zones correspond to the thickness of the white coloration as observed on the sample (i.e. the shear band). This shear band is surrounded by third zone with initial porosity and healthy grains. In globally undrained conditions, such changes in the microstructure of the rock allows for local fluid exchanges between compacting zones that expel fluid and dilating ones that absorb it. At high confinement, pore pressure generation inside the band leads locally to liquefaction of the crushed material which results into the formation of connected channels in the heart of the band. One application of this study is the influence of shear banding on the flow of fluids and contaminants. Although permeability was not directly measured in our experiments, microstructural observations highlight several features which may significantly affect fluid flow and hydraulic properties in a deformed sample. Under relatively high confining pressure, the center of the shear band is expected to inhibit fluid migration due to reduced grain size. Actually, the powder inside the band and the corresponding porosity reduction fill the porous space and can be a natural barrier to fluid flows. The zones surrounding the center of the shear band show a strong dilatancy which will allow a high permeability. Another aspect is the induced anisotropy of the rock permeability as the fluid flow can be enhanced in the direction parallel to the shear band and significantly reduced in the direction perpendicular to it. At large scale, similar phenomena can be expected in faulted zones when sheared. Changes in the structure of the gouge material, such as grain crushing and porosity reduction, will then affect the global permeability of the reservoir.

Sulem, J.; Ouffroukh, H.; El Bied, A.

2003-04-01

481

Viewpoints: Chemists on Chemistry  

NASA Astrophysics Data System (ADS)

It is a great pleasure for me to be associated with Viewpoints: Chemists on Chemistry, a series of papers in this Journal that will delineate the recent past and the near-term future of our science. Viewpoints is a major feature of the celebration of the Journal of Chemical Education's 75th anniversary year. It is being supported by The Camille and Henry Dreyfus Foundation, Inc., which recently celebrated its own 50th anniversary. Each paper in the Viewpoints series will be written by a chemist or group of chemists with special expertise in a particular field, with the aim of providing an overview of that field&'s accomplishments, importance, and prospects. The goal is to reflect on developments during the past 50 years and to predict how each field will evolve over the next 25 years. The total perspective encompassed by Viewpoints corresponds with the 75 years of this Journal's lifetime and reflects its comprehensive interest in all of chemistry. The 50-year retrospective view of each field corresponds with the period during which the Camille and Henry Dreyfus Foundation has been supporting the chemical sciences.

Seaborg, Glenn T.

1998-01-01

482

THE GUY ZONE  

NSDL National Science Digital Library

Here is a collection of links chosen by the creators of the Guy Zone. We think these websites are perfect for guys. Reading-related Sites: Guys Read This is the site that started it all. Author Jon Scieszka, who wrote books such as the \\"Time Warp Trio\\" series and \\"Squids Will Be Squids,\\" created it just for guys. It\\'s one place to look for book recommendations made by other guys. Gordon Korman s Official Website The official website of author ...

Laz, Mrs.

2008-01-28

483

Connectivity-oriented urban projects  

Microsoft Academic Search

This thesis is about connections in the built environment, networked connections for the mobility of people at the smallest scale of the urban realm: the pedestrian scale.\\u000aIt deals with applications of the new science of networks as a tool for observation and assessment of connectivity in the urban space. It explores networks theoretically through the study recently discovered scientific

E. Philibert Petit

2006-01-01

484

Pseudo-Hamiltonian-connected graphs  

Microsoft Academic Search

Given a graph G and a positive integer k, denote by G(k) the graph obtained from G by replacing each vertex of G with an independent set of size k. A graph G is called pseudo-k Hamiltonian-connected if G(k) is Hamiltonian-connected, i.e., every two distinct vertices of G(k) are connected by a Hamiltonian path. A graph G is called pseudo

Gerard J. Chang; Xuding Zhu

485

Pseudo-Hamiltonian-connected graphs  

Microsoft Academic Search

Abstract Given a graph G and a positive integer k, denote by G[k] the graph obtained from G by replacing each vertex of G with an independent set of size k. A graph G is called pseudo-k Hamiltonian-connected if G[k] is Hamiltonian-connected, i.e., every two distinct vertices of G[k] are connected by a Hamiltonian path. A graph G is called

Gerard J. Chang; Xuding Zhu

2000-01-01

486

Trojans in habitable zones.  

PubMed

With the aid of numerical experiments we examined the dynamical stability of fictitious terrestrial planets in 1:1 mean motion resonance with Jovian-like planets of extrasolar planetary systems. In our stability study of the so-called "Trojan" planets in the habitable zone, we used the restricted three-body problem with different mass ratios of the primary bodies. The application of the three-body problem showed that even massive Trojan planets can be stable in the 1:1 mean motion resonance. From the 117 extrasolar planetary systems only 11 systems were found with one giant planet in the habitable zone. Out of this sample set we chose four planetary systems--HD17051, HD27442, HD28185, and HD108874--for further investigation. To study the orbital behavior of the stable zone in the different systems, we used direct numerical computations (Lie Integration Method) that allowed us to determine the escape times and the maximum eccentricity of the fictitious "Trojan planets." PMID:16225431

Schwarz, Richard; Pilat-Lohinger, Elke; Dvorak, Rudolf; Erdi, Balint; Sándor, Zsolt

2005-10-01

487

Natural Products Version 2.0: Connecting Genes to Molecules  

PubMed Central

Natural products have played a prominent role in the history of organic chemistry, and they continue to be important as drugs, biological probes, and targets of study for synthetic and analytical chemists. In this perspective, we explore how connecting Nature’s small molecules to the genes that encode them has sparked a renaissance in natural product research, focusing primarily on the biosynthesis of polyketides and nonribosomal peptides. We survey monomer biogenesis, coupling chemistries from templated and non-templated pathways, and the broad set of tailoring reactions and hybrid pathways that give rise to the diverse scaffolds and functionalization patterns of natural products. We conclude by considering two questions: What would it take to find all natural product scaffolds? What kind of scientists will be studying natural products in the future?

Walsh, Christopher T.; Fischbach, Michael A.

2009-01-01

488

Telecoil: Connecting Directly to Sound  

MedlinePLUS

... Telecoil Connecting Directly to Sound ? What is hearing assistive technology? (HAT) There are three types of wireless hearing assistive technology discussed here: ? The hearing loop a wire that ...

489

A Spoonful of C[subscript 12]H[subscript 22]O[subscript 11] Makes the Chemistry Go Down: Candy Motivations in the High School Chemistry Classroom  

ERIC Educational Resources Information Center

|A food motivation activity, using a candy bar for high school chemistry classes is described. The use of everyday items like candy makes lab sessions interesting for students and may also help connect chemical concepts to their observable world and encourage them to ask questions.|

Ennever, Fanny K.

2007-01-01

490

Nutrient flux through soils and aquifers to the coastal zone of Guam (Mariana Islands)  

Microsoft Academic Search

Nitrification enriches terrestrial soil waters with nitrate, and other solutes also leach rapidly (within hours to days after saturating rain) through Guam's northern karst plateau into a largely unconfined carbonate aquifer system. Nutrient chemistry and discharge of these enriched aquifer waters into the inter- and subtidal zone was measured to evaluate the importance of this flux to the coastal nutrient

Ernest A. Matson

1993-01-01

491

LATE CRETACEOUS MAGMATISM OF THE CHELOPECH REGION, CENTRAL SREDNOGORIE MAGMATIC ZONE, BULGARIA  

Microsoft Academic Search

The Late Cretaceous magmatism in Chelopech region is characterised by andesitic, latitic to trachydacitic lava flows (probably products of a chemically zoned magmatic chamber), subvolcanic bodies and altered dykes with latite chemistry. The Sr isotope (0.7049 to 0.7054) signature suggests derivation from melts generated in a mantle source modified by the addition of crustal material from the subducted slab.

S. STOYKOV; Y. YANEV; R. MORITZ; D. FONTIGNIE