A mechanistic study of methyl parathion hydrolysis by a bifunctional organoclay

The mechanism for the hydrolysis of methyl parathion (MP) by a bifunctional quaternary-ammonium based long-chained organclay(LCOC) containing an alkylamine (-CH2CH2-NH2) headgroup was elucidated. The pathway of the catalytic hydrolysis of methyl parathion by the LCOC was defined by following the effect of replacing H20 with D20, by replacing the primary amino headgroup by a tertiary amino group, and by a detailed mathematical analysis of the proposed reaction scheme. A phosphorothioate isomer of MP was formed in the presence of the LCOC as an intermediate reaction product, initially increasing in concentration and then disappearing. The isotope effect was minimal and substituting a tertiary amine in the LCOC increased the rate of MP hydrolysis. A mechanism is proposed in which hydrolysis of MP can proceed via both a direct route (specific base hydrolysis) and through the formation of the isomer which then undergoes specific base hydrolysis more rapidly than the parent MP. The relative importance of each pathway is a function of pH with the direct hydrolysis of MP being predominant at higher pH values (pH > 10) and the isomer intermediate pathway predominating at lower pH values (pH approximately 8-10).     

Correction to diamond et al. (2010).

Reports an error in "Ongoing traumatic stress response (OTSR) in Sderot, Israel" by Gary M. Diamond, Joshua D. Lipsitz, Zvi Fajerman and Omit Rozenblat (Professional Psychology: Research and Practice, 2010[Feb], Vol 41[1], 19-25). In the article “Ongoing Traumatic Stress Response (OTSR) in Sderot, Israel,” by Diamond, Lipsitz, Fajerman and Rozenblat (Professional Psychology: Research and Practice, 2010, Vol. 41, No. 1., pp. 19–25), due to a production error, the last author’s name was misspelled in the byline and the author note. The correct spelling is Ornit Rozenblat. (The following abstract of the original article appeared in record 2010-02467-003.) In Sderot, a small city in southern Israel, seven years of continuous missile attacks have led to dramatic increases in treatment seeking for anxiety symptoms. For some clients, the clinical picture is consistent with a diagnosis of post traumatic stress disorder (PTSD). For other clients, however, the onset and constellation of symptoms are less typical of PTSD. In these cases, anxiety symptoms seem to evolve gradually and be associated with ongoing, daily stress about imminent attacks, rather than with a discrete, past traumatic event. Much of their avoidance behavior is reality based. They report hyperarousal, severe distress, and loss of control during and immediately following actual missile attacks. However, they are less likely to exhibit reexperiencing symptoms. Furthermore, in contrast to the typical presentation of PTSD, their symptoms tend to diminish dramatically or completely resolve when they are no longer within harm’s way. We suggest that this clinical presentation may be best understood as an ongoing traumatic stress response (OTSR), rather than PTSD or PTSD symptoms. We consider diagnostic features which discriminate between these two phenomena as well as implications for treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microbial and algal oils: Do they have a future for biodiesel or as commodity oils?

We review the prospects of using yeasts and microalgae as sources of cheap oils that could be used for biodiesel. We conclude that yeast oils, the cheapest of the oils producible by heterotrophic microorganisms, are too expensive to be viable alternatives to the major commodity plant oils. Algal oils are similarly unlikely to be economic; the cheapest form of cultivation is in open ponds which then requires a robust, fast‐growing alga that can withstand adventitious predatory protozoa or contaminating bacteria and, at the same time, attain an oil content of at least 40% of the biomass. No such alga has yet been identified. However, we note that if the prices of the major plant oils and crude oil continue to rise in the future, as they have done over the past 12 months, then algal lipids might just become a realistic alternative within the next 10 to 15 years. Better prospects would, however, be to focus on algae as sources of polyunsaturated fatty acids.     

Chaim Weizmann as a Scientist – From Berlin to the End of His Manchester Period

After finishing high school in Pinsk, Russia, Chaim Weizmann studied two semesters in the Technical University of Darmstadt, returned home for a year, and in 1895 registered as a chemistry student at the Charlottenburg Technical University at Berlin. He studied and worked in the research group of A. Bistrzycki on synthetic dyestuffs and received a patent in the field. He graduated after 3 years and followed Bistrzycki to Freiburg, Switzerland, where he received in January 1899 a Ph.D. degree with a grade of Magna cum laude. He became a Privatdocent at the University of Geneva, worked in Prof. C. Graebe’s group, published papers and patents and sold patents. In 1904, he moved to the University of Manchester in the UK and collaborated with Prof. William Henry Perkin Jr. in research on synthetic dyestuffs and natural products, and started to work with him on the synthesis of acetone by fermentation. He failed to be nominated to Perkin’s chair when Perkin left in 1913, but became a Reader and head of the biochemistry laboratory. After a conflict with Perkin, he continued alone with the acetone synthesis project, found a bacterium that fermented the starch of corn, potatoes, and chestnuts to acetone and butyl alcohol, which was more efficient than a bacterium found by Perkin and co-workers. The urgent need for acetone in World War One for military purpose and the high yield of his bacterium in acetone-producing fermentation, compared with the bacterium of his competitors, made Weizmann’s process the favored one by the British military during the war. Weizmann scaled up acetone production and increased its yield by increasing the sophistication of the process by using a high degree of sterilization. For his contributions he is regarded as the father of industrial biotechnology. His contribution to the war effort opened the door to the British leadership in his Zionistic activity. However, this activity and his scientific activity at later periods are not covered in this article.     

Zeolite membranes for hydrogen production from natural gas: state of the art

Journal of Porous Materials - Currently, hydrogen is produced industrially by processes requiring high energy consumption, especially by cracking fossil fuels and by splitting water. In recent...     

Self-calibration and mirror center offset elimination of a multi-beam laser tracking system

New methods for the self-calibration of a laser tracking coordinate measuring machine are reported in this paper. Proper calibration of a laser tracking system is essential prior to using such a device for coordinate measuring. The task is nontrivial in the absence of other measurement systems of comparable accuracy. One has to rely on a self-calibration strategy. Two calibration methods, one based on a four-tracker system and the other based on three trackers combined with precision planes to constrain the target motion, are proposed. Iterative optimization algorithms are developed. A basic assumption for these calibration methods is that there is no tracking mirror center offset. Error analysis presented in this paper reveals that measurement errors due to mirror center offsets are significant. Therefore before calibrating the laser tracking system, the mirrors must be adjusted so that the laser beams hit the mirror centers. The adjustment is a tedious manual task. In the FAU laser tracking machine, an adjustment procedure which employs a four quadrant detector has been devised for the elimination of tracking mirror center offsets. Simulation and experimental results are presented to demonstrate the effectiveness of the suggested methods.     

Sigmund Freud and Minna Bernays: Primal curiosity, primal scenes, primal fantasies--And prevarication.

Attacks on Freud's theories on sexuality began when Freud launched his studies on hysteria in the last decade of the 19th century and are still ongoing. The latest cavil is embedded in a sensation exploded in the summer of 2006 by Franz Maciejewski of Heidelberg, Germany. It was publicized in front-page reportage by New York Times columnist Ralph Blumenthal (2006): "A Century-Old Swiss Hotel Log Hints at an Illicit Desire That Dr. Freud Didn't Repress," additionally editorialized as adequate "to impugn [Freud's] reputation" (p. A4). In this article, arguments ad hominem, bordering on Freud-bashing, concerning Freud as a person and his relationship with his sister-in-law Minna Bernays, are separated from arguments ad rem, regarding the merits of Freud's theory of the Oedipus complex. The evidence presented by Maciejewski is found to be flawed and to not rise above the level of conjecture. Similarly, his construction that the alleged sexual affair between Freud and his sister-in-law was tantamount to incest, and thus source of theory of the Oedipus complex, has no standing either. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

5. VCNR type characteristic in thin film amorphous TeGeAsSi films

In the hope of further understanding the memory and switching effects of amorphous evaporated semi-conductor films, the current-voltage curve of the quarternary system TeGeAsSi was experimentally examined and our findings are discussed below.     

Plastic behavior of composites and porous media under isotropic stress

The macroscopic relation between isotropic stress and dilatation is analyzed for a composite consisting of elasto-plastic matrix and elastic particles or empty cavities (porous material), on the basis of the composite spheres assemblage model. Results show that plastic macro-dilatation is not significant for elastic particles but is very significant for porous materials.     

The Minimax and Maximin Location Problems on a Network with Uniform Distributed Weights

In this paper we consider the weighted minimax and maximin location problems on the network when the weights are drawn from a uniform distribution. In the minimax (maximin) problem with stochastic demand the probability that the maximum (minimum) weighted distance between the facility and demand points exceeding (falling short of) a given value T is minimized. Properties of the solution points for both problems are proven and algorithms are presented.