Characterization of a new iron-on-zeolite Y Fischer-Tropsch catalyst

Iron pentacarbonyl adsorbed on dry Na-Y zeolite can be oxidized at subambient temperatures into Fe203 located in the zeolite supercages (catalyst I). When catalyst I is hydrogen reduced at 575 K most of the iron has agglomerated externally to the zeolite (catalyst 11). When the iron carbonyl is thermally decomposed in vacuo at 525 K, an iron phase with a very low degree of dispersion is again obtained (catalyst 111). During a Fischer-Tropsch reaction most of the iron is transformed into a Hagg-type carbide phase, located externally to the zeolite. Catalysts I1 and 111 rapidly reach steady state and show a Schulz-Flory-type of product distribution, the Hagg carbide being the active phase. Catalyst I slowly moves to steady state and Schulz-Flory behavior. Product selectivity is only found on this catalyst during transient conditions. The physical information on the three catalysts before and after reaction was obtained with transmission electron microscopy and Mossbauer and EXAFS spectroscopies. These techniques supplied consistent and complementary evidenc

The selection and professional training of teachers : a study based upon questionnaire returns from selected teachers and school administrators in California, as collected by the State Department of Education

This paper is concerned with the professional preparation of teachers and seek to set forth and evaluate the ideas which teachers in the field think would improve the chances of success for the teachers now in training. Obviously, the person to realize the advantages and disadvantages if the preparation which he has had. It is apparent also, that our present system of educating teachers is out of step with present day needs in some respects. A small number of responses were received from the elementary group and therefore the conclusions which will be set forth in this article are predicated very largely upon the answers received from the others. Nevertheless, a high percentage of the suggestions and criticisms which the survey produced may be applied directly to the elementary schools. Evaluation of answers was made somewhat difficult by the fact that in some cases a given answer was not that or an individual but of a committee of teachers. Of course, such a response is really entitled to more consideration, but to know just how much more is something belonging to speculative rather than mathematical thinking. Many replies did not bear directly upon the question. Where replies do not seem to bear directly on the question considered, these will be placed at the end of each group under the heading of Miscellaneous Replies . The responses from the committees especially, showed that the thinking was clear, concise and well organized. In many cases several answers were grouped under one heading in the compilation. Perhaps there is a need for further grouping under basic fields, but in some cases we do not have the word or words to name the basic field. This is true especially, concerning basic traits for teachers

Gait Velocity Estimation using time interleaved between Consecutive Passive IR Sensor Activations

Gait velocity has been consistently shown to be an important indicator and predictor of health status, especially in older adults. It is often assessed clinically, but the assessments occur infrequently and do not allow optimal detection of key health changes when they occur. In this paper, we show that the time gap between activations of a pair of Passive Infrared (PIR) motion sensors installed in the consecutively visited room pair carry rich latent information about a person's gait velocity. We name this time gap transition time and show that despite a six second refractory period of the PIR sensors, transition time can be used to obtain an accurate representation of gait velocity. Using a Support Vector Regression (SVR) approach to model the relationship between transition time and gait velocity, we show that gait velocity can be estimated with an average error less than 2.5 cm/sec. This is demonstrated with data collected over a 5 year period from 74 older adults monitored in their own homes. This method is simple and cost effective and has advantages over competing approaches such as: obtaining 20 to 100x more gait velocity measurements per day and offering the fusion of location-specific information with time stamped gait estimates. These advantages allow stable estimates of gait parameters (maximum or average speed, variability) at shorter time scales than current approaches. This also provides a pervasive in-home method for context-aware gait velocity sensing that allows for monitoring of gait trajectories in space and time

Modulating hypoxia-inducible transcription by disrupting the HIF-1-DNA interface

Transcription mediated by hypoxia-inducible factor (HIF-1) contributes to tumor angiogenesis and metastasis but is also involved in activation of cell-death pathways and normal physiological processes. Given the complexity of HIF-1 signaling, it could be advantageous to target a subset of HIF-1 effectors rather than the entire pathway. We compare the genome-wide effects of three molecules that each interfere with the HIF-1–DNA interaction: a polyamide targeted to the hypoxia response element, small interfering RNA targeted to HIF-1α, and echinomycin, a DNA-binding natural product with a similar but less specific sequence preference than the polyamide. The polyamide affects a subset of hypoxia-induced genes consistent with its binding site preferences. For comparison, HIF-1α siRNA and echinomycin each affect the expression of nearly every gene induced by hypoxia. Remarkably, the total number of genes affected by either polyamide or HIF-1α siRNA over a range of thresholds is comparable. The data show that polyamides can be used to affect a subset of a pathway regulated by a transcription factor. In addition, this study offers a unique comparison of three complementary approaches towards exogenous control of endogenous gene expression

Data-driven analysis methods for the measurement of reconstructed jets in heavy ion collisions at RHIC and LHC

We present data-driven methods for the full reconstruction of jets in heavy ion collisions, for inclusive and co-incidence jet measurements at both RHIC and LHC. The complex structure of heavy ion events generates a large background of combinatorial jets, and smears the measured energy of the true hard jet signal. Techniques to correct for these background effects can induce biases in the reported jet distributions, which must be well controlled for accurate measurement of jet quenching. Using model studies, we evaluate the proposed methods for measuring jet distributions accurately while minimizing the fragmentation bias of the measured population.Comment: 5 pages, 14 figures, Hard Probe 2012 Conference Proceedin

On a minimal model for estimating climate sensitivity

In a recent issue of this journal, Loehle (2014) presents a "minimal model" for estimating climate sensitivity, identical to that previously published by Loehle and Scafetta (2011). The novelty in the more recent paper lies in the straightforward calculation of an estimate of transient climate response based on the model and an estimate of equilibrium climate sensitivity derived therefrom, via a flawed methodology. We demonstrate that the Loehle and Scafetta model systematically underestimates the transient climate response, due to a number of unsupportable assumptions regarding the climate system. Once the flaws in Loehle and Scafetta's model are addressed, the estimates of transient climate response and equilibrium climate sensitivity derived from the model are entirely consistent with those obtained from general circulation models, and indeed exclude the possibility of low climate sensitivity, directly contradicting the principal conclusion drawn by Loehle. Further, we present an even more parsimonious model for estimating climate sensitivity. Our model is based on observed changes in radiative forcings, and is therefore constrained by physics, unlike the Loehle model, which is little more than a curve-fitting exercise

The Expectation Monad in Quantum Foundations

The expectation monad is introduced abstractly via two composable adjunctions, but concretely captures measures. It turns out to sit in between known monads: on the one hand the distribution and ultrafilter monad, and on the other hand the continuation monad. This expectation monad is used in two probabilistic analogues of fundamental results of Manes and Gelfand for the ultrafilter monad: algebras of the expectation monad are convex compact Hausdorff spaces, and are dually equivalent to so-called Banach effect algebras. These structures capture states and effects in quantum foundations, and also the duality between them. Moreover, the approach leads to a new re-formulation of Gleason's theorem, expressing that effects on a Hilbert space are free effect modules on projections, obtained via tensoring with the unit interval.Comment: In Proceedings QPL 2011, arXiv:1210.029