Feasibility study on non-windowed solar reactor: ZnO carboreduction as an example

This paper describes a solar reactor in which a ceramic crucible replaces the window. The crucible is made of SiC and combines two functions: heating surface and sealing partition of the reaction volume. The reactor is irradiated from top using a beam down optics. The main design issues are the sealing of the reactor and the thermal stresses created in the crucible. Careful design of the temperature profile subsequent with stress analyses, especially on the crucible, which is exposed directly to the concentrated solar radiation, and the material of construction can solve mechanical failures of the crucible. The modeling validity was verified experimentally for different operating conditions, both without reaction and with the endothermic carboreduction of ZnO.     

Reflections stimulated by the comments of Shadish (2010) and West and Thoemmes (2010).

This article offers reflections on the development of the Rubin causal model (RCM), which were stimulated by the impressive discussions of the RCM and Campbell’s superb contributions to the practical problems of drawing causal inferences written by Will Shadish (2010) and Steve West and Felix Thoemmes (2010). It is not a rejoinder in any real sense but more of a sequence of clarifications of parts of the RCM combined with some possibly interesting personal historical comments, which I do not think can be found elsewhere. Of particular interest in the technical content, I think, are the extended discussions of the stable unit treatment value assumption, the explication of the variety of definitions of causal estimands, and the discussion of the assignment mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

深井降温技术中的新方法—冰冷却系统

本文介绍了一种应用冰冷却系统对深井降温的新技术,并对它的技术特点及经济效益作出了初步分析,对于深井的降温,冰冷却系统具有明显的优越性。     

Organo-clay formulations of pesticides: reduced leaching and photodegradation

Adsorption of organic cations on several clay minerals is reviewed with an emphasis on the effect of ionic strength and modeling. The clay exchanged with suitable organic cations forms a basis for ecologically acceptable formulations of herbicides with reduced leaching, ground water contamination and enhanced weed control efficacy. Incomplete neutralization of the clay surface charge by an organic cation may be advantageous in achieving maximal adsorption of hydrophobic herbicides. One conclusion from these studies is that optimization of clay-based herbicide formulations requires a selection of structurally compatible organic cations preadsorbed on the clay at optimal coverage. New experimental results are presented for alachlor formulations, which significantly reduce herbicide leaching under conditions of heavy irrigation. We were able to demonstrate that organo-clay formulations of alachlor and metolachlor can increase crop yields in a 1-year field experiment. The photostabilization of pesticides is reviewed and improved organo-clay formulations of the herbicides trifluralin and norflurazon are described. A pillared clay, nanocomposite micro- and/or meso porous material, was effective in reducing leaching and in conferring photostabilization, without added organic cations.     

The ethics of consulting for the tobacco industry

This article describes how and why I became involved in consulting for the tobacco industry. I briefly discuss the four relatively distinct statistical topics that were the primary focus of my work, all of which have been central to my published academic research for over three decades: missing data; causal inference; adjustment for covariates in observational studies; and meta-analysis. To me, it is entirely appropriate to present the application of this academic work in a legal setting.     

Signal amelioration of electrophoretically deposited whole-cell biosensors using external electric fields

This paper presents an integrated whole-cell biochip system where functioning cells are deposited on the solid micro-machined surfaces while specially designed indium tin oxide electrodes that can be used to apply controllable electric fields during various stages; for example during cell deposition. The electrodes can be used also for sensing currents associated with the sensing mechanisms of electrochemical whole-cell biosensors. In this work a new approach integrating live bacterial cells on a biochip using electrophoretic deposition is presented. The biomaterial deposition technique was characterized under various driving potentials and chamber configurations. An analytical model of the electrophoretic deposition kinetics was developed and presented here. The deposited biomass included genetically engineered bacterial cells that may respond to toxic material exposure by expressing proteins that react with specific analytes generating electrochemically active byproducts. In this study the effect of external electric fields on the whole-cell biochips has been successfully developed and tested. The research hypothesis was that by applying electric fields on bacterial whole-cells, their permeability to the penetration of external analytes can be increased. This effect was tested and the results are shown here. The effect of prolonged and short external electric fields on the bioelectrochemical signal generated by sessile bacterial whole-cells in response to the presence of toxins was studied. It was demonstrated that relatively short 10 ms external DC electric pulse improves the performance of bacterial biosensors by 15% relative to un-biased biosensors. The application of prolonged 1 h external alternating electric fields deteriorated the whole-cell performance in the presence of toxins. In this paper we present the electrode apparatus and methods, as well as the characterization results, e.g. signal vs. time and induction factor, of such chips and discussing the highlight and problems of this new concept.