17,817 research outputs found
Diamond films from combustion of methyl acetylene and propadiene
To date diamond films grown with the combustion technique have used either acetylene or, rarely, ethylene as the fuel. However, there are barriers to large scale commercialization of the combustion technique using either fuel. For example, acetylene is relatively expensive and difficult to handle, while the use of ethylene gives relatively low growth rates. In this letter we propose replacing acetylene with MAPPTM gas, a commercial mixture of methyl acetylene and propadiene in liquefied petroleum gas (primarily propylene). MAPP gas is considerably cheaper, safer, and easier to handle than acetylene. Furthermore, the experiments described here suggest that MAPP gas flames are only slightly less efficient than acetylene flames at converting fuel carbon atoms into diamond
Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset
CRU TS (Climatic Research Unit gridded Time Series) is a widely used climate dataset on a 0.5 degrees latitude by 0.5 degrees longitude grid over all land domains of the world except Antarctica. It is derived by the interpolation of monthly climate anomalies from extensive networks of weather station observations. Here we describe the construction of a major new version, CRU TS v4. It is updated to span 1901-2018 by the inclusion of additional station observations, and it will be updated annually. The interpolation process has been changed to use angular-distance weighting (ADW), and the production of secondary variables has been revised to better suit this approach. This implementation of ADW provides improved traceability between each gridded value and the input observations, and allows more informative diagnostics that dataset users can utilise to assess how dataset quality might vary geographically
Restorative practice and behaviour management in schools: discipline meets care.
The history of restorative practices in New Zealand schools is directly related to projects such as the Suspension Reduction Initiative (SRI) and the more recent Student Engagement Initiative (SEI); thus the origins of restorative practices in schools are linked with behaviour management and school discipline. During the same period, teachers' work has become more complex: They are working with an increasingly diverse range of students, which in turn requires epistemologically diverse teaching and relationship-building approaches to ensure maximum participation for all. Teachers are looking for new and better ways to interact with students in their classrooms, and those responsible for disciplinary systems are looking to restorative practice for new ways to resolve the increasing range and number of difficulties between teachers and students, students and other students, and between the school and parents. Restorative practices (RP) are currently seen as a way of achieving all this, so they carry a huge burden of hope. Relationship skills are a key competency in the new curriculum, and the philosophy of restoration offers both a basis for understanding and a process for putting this agenda into practice. In effect, it means educating for citizenship in a diverse world, including teaching the skills of conflict resolution. If we accept this philosophy, the curriculum for teacher education will require significant changes in what students are taught about behaviour and classroom management
Atlantic Exchange: Case Studies of Housing and Community Redevelopment in the United States and the United Kingdom
Examines lessons learned from community redevelopment initiatives in Birmingham, England, and Chicago. Explores physical, managerial, and demographic changes and issues of place identity, community cohesion, and the communities' place in city initiatives
Evaluation of Phosphorus Fertilizer Materials on Two Benchmark Soils of the Tropics
One possible strategy for improving the economic attractiveness of P fertilization on acid P-deficient soils in the tropics was investigated agronomically in two field experiments on sites of the Benchmark Soils Project in the Philippines and Indonesia. The specific strategy is the use of phosphate rock for direct application or partially acidulated or thermally altered phosphate rock in place of acidulated phosphates, e.g., superphosphate. The experiments were conducted on Hydric Dystr'andept soil on a site near Naga City, Camarines Sur, Philippines and on a Typic Paleudult on a site located near Kotabumi, Lampung on the island of Sumatra, Indonesia. The experiments compared crop response (primarily maize) to one highly reactive phosphate rock (North Carolina, NC) and one moderately reactive phosphate rock (Central Florida, CF), which were used because they are well characterized with respect Co reactivity. These two P-sources were used in finely-ground form and also each was used in a different minimally altered form. For the North Carolina rock, a minigranular form was used form, Co determine if the minigranulation process can be used Co overcome the handling and transportation problems of the dusty, finely-ground form without reducing agronomic effectiveness. For the Central Florida rock a minigranular form which was 20% partially acidulated with phosphoric acid was used as the minimally altered form to determine if partial acidualcion of moderately reactive phosphate rocks could adequately improve agronomic effectiveness on acid soils.
Comparing the results for the two soils sites in the first crop, a large difference between sources is seem on the Hydric Dystrandept, while no significant differences are seen between sources on the Typic Paleudult. In the second crop, fresh applications of superphosphate were made on former control plots on both sites and the other treatments were left as residuals. On the Hydric Dystrandept significant differences between sources are seen in the residual effects. On the Typic Paleudult, soybeans were planted, and no significant differences are seen between residual effects of the sources.
The higher P requirement evidenced by the Hydric Dystrandept as compared to the Typic Paleudult, made reapplication necessary at all rates for the third crop on the Hydric Dystrandept, whereas for the Typic Paleudult, reapplication of all sources was made only on the LO kg/ha plots, on which 70 kg P/ha were applied to permit comparison with the residual 80 kg P/ha treatments. The third season yield results again show no significant differences between sources on the Typic Paleudult, even for the reapplications of 70 kg P/ha, whereas some significant differences are seem for the reapplication on the Hydric Dystrandept.
With respect to rock modifications on the Hydric Dystrandept, where differences between sources are detected, minigranulation of the NC rock did not reduce its effectivesness, thus confirming the agronomic viability of the process. Also on the Hydric Dystrandept, partial acidulation did improve the performance of the OF rock, but not sufficiently to make it equal Co superphosphate or the NC forms.
In summary, these results indicate that the Typic Paleudult is well suited for direct application of phosphate rocks of moderate and possibly lower reactivity, whereas the Hydric Dystrandept requires phosphate rocks of high reactivity to obtain yields comparable to those of superphosphate. This difference in performance of phoshpate rock between the two soils can be related to the slightly lower pH of the Typic Paleudult and also, its lower P-sorption capacity, in comparison to the Hydric Dystrandept.
The results from the post-harvest P soil test analyses indicate that neither the modified Truog nor the Bray P I procedure can be satisfactorily used to predict residual P in the Hydric Dystrandept when P-sources varying in solubility are used. In the Typic Paleudult there is some indication that the Bray I procedure underestimates residual P from the CF sources; however, it appears that minor modification of the procedure by increasing the solution to soil ratio could overcome this problem. This is considered to be a worthwhile area for research since direct application of phosphate rock over the complete range of solubility appears to be an agronomically advisable practice for the Typic Paleudult and similar soils
Respect for the Living and Respect for the Dead: Return of Indian and Other Native American Burial Remains
Testing for a unit root in the presence of a possible break in trend
In this paper we consider the issue of testing a time series for a unit root in the possible presence of a break in a linear deterministic trend at some unknown point in the series. We propose a break fraction estimator which, in the presence of a break in trend, is consistent for the true break fraction at rate Op(T^-1) when there is either a unit root or near-unit root in the stochastic component of the series. In contrast to other estimators available in the literature, when there is no break in trend, our proposed break fraction estimator converges to zero at rate Op(T^-1/2). Used in conjunction with a quasi difference (QD) detrended unit root test that incorporates a trend break regressor in the deterministic component, we show that these rates of convergence ensure that known break fraction null critical values are applicable asymptotically. Unlike available procedures in the literature this holds even if there is no break in trend (the true break fraction is zero), in which case the trend break regressor is dropped from the deterministic component and standard QD detrended unit root test critical values then apply. We also propose a second testing procedure which makes use of a formal pre-test for a trend break in the series, including a trend break regressor only where the pre-test rejects the null of no break. Both procedures ensure that the correctly sized (near-) efficient unit root test that allows (does not allow) for a break in trend is applied in the limit when a trend break does (does not) occur.Unit root test; quasi difference de-trending; trend break; pre-test; asymptotic power
Deconstructing Digital-to-Analog Converters with Inlet
Many statisticians would agree that, had it not been for DNS, the understanding of hierarchical databases might never have occurred. In fact, few systems engineers would disagree with the deployment of thin clients, demonstrates the structured importance of steganography. In or- der to address this riddle, we better understand how cache coherence [14] can be applied to the construction of RPCs
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