140,293 research outputs found
The Effects of Possible Contamination on the Radiocarbon Dating of the Dead Sea Scrolls II: Empirical Methods to Remove Castor Oil and Suggestions for Redating
No full textWhile kept at the Rockefeller Museum in East Jerusalem, many Dead Sea Scroll fragments were exposed to castor oil by the original team of editors in the course of cleaning the parchments. Castor oil must be regarded as a serious contaminant in relation to radiocarbon dating. If modern castor oil is present and is not removed prior to dating, the 14C dates will be skewed artificially towards modern values. Earlier, it was shown that the standard AAA pretreatment procedure used in the 2 previous studies dating Dead Sea Scroll samples is not capable of removing castor oil from parchment samples. In the present work, we show that it is unlikely that castor oil reacts with the amino acids of the parchment proteins, a finding which leaves open the possibility of devising a cleaning method that can effectively remove castor oil. We then present 3 different pretreatment protocols designed to effectively remove castor oil from parchment samples. These involve 3 different cleaning techniques: extraction with supercritical CO2, ultrasound cleaning, and Soxhlet extraction—each with their own advantages and disadvantages. Our data show that the protocol involving Soxhlet extraction is the best suited for the purpose of decontaminating the Dead Sea Scrolls, and we recommend that this protocol be used in further attempts to 14C date the Dead Sea Scrolls. If such an attempt is decided on by the proper authorities, we propose a list of Scroll texts, which we suggest be redated in order to validate the 14C dates done earlier.
A case of accidental Ricin poisoning
No full textA case report of accidental, mild ricin poisoning by ingestion of ten Castor beans by a 70 year old man. The clinical presentation is followed by a discussion about the toxicity of ricin, its use and misuse and the contrast between the toxicity of pure ricin and the ingestion of castor beans. Management of castor bean poisoning is also discussed.peer-reviewe
G. Radet. Alexandre le Grand
No full textCohen Robert. G. Radet. Alexandre le Grand. In: Revue des Études Grecques, tome 45, fascicule 213, Octobre-décembre 1932. p. 427
G. Radet. Alexandre le Grand
No full textCohen Robert. G. Radet. Alexandre le Grand. In: Revue des Études Grecques, tome 45, fascicule 213, Octobre-décembre 1932. p. 427
Selectivity of pre and postemergence herbicides in single or combined applications in castor crop.
No full textOne of the main challenges in castor crop (Ricinus communis L.) production is efficient weed management mainly due to limited options of selective herbicides. This study evaluated the selectivity of herbicides applied alone or in combination in pre- and postemergence applications in castor crop. Two field experiments were carried out under irrigation conditions in a semi-arid region of Northeast Brazil. It was found that the visual symptoms of phytointoxication of the herbicides used on castor were mild in both experiments. Consequently, there were no significant interferences on plant height, number of racemes, and grain (seed) yield. Pre-emergence applications (g ha−1) of trifluralin (1800), pendimethalin (1500), clomazone (750), clomazone + trifluralin (750 + 1800), and clomazone + pendimethalin (750 + 1500) followed by chlorimuron-ethyl in postemergence (15 g ha−1) are selective to castor. The application (g ha−1) of pendimethalin + clomazone (1000 + 500) in pre-emergence, associated with chlorimuron-ethyl (10 and 15), metamitron (2800 and 4200), ethoxysulfuron (60 and 80), or halosulfuron-methyl (75 and 112.5) in one or two applications in postemergence, as single or split applications, in an interval of 14 days, are selective to castor crop
Castor Dynamic Investigation
No full textDynamic behaviour of vehicles having castored wheels can be affected by wheel shimmy phenomenon, that is a self-sustained vibration of the whole castor around the steering axis. This article presents a shimmy investigation conducted on a laboratory castor characterized by low lateral stiffness; numerical models show that this characteristics leads to three different stability conditions depending on the forward velocity: at low speeds the system is unstable and the castor is affected by shimmy oscillations; then there is an intermediate speed range in which the system recovers stability; finally, above a threshold speed value, the system returns to be unstable. The experimental investigation mainly aims to compare the numerical results with the experimental ones and to define the steering damping required to stabilize the castor according to its main features
Castor
No full textMedium: etchingprintsSigned l.r., pencil "F L Griggs" ; signed and dated on plate l.r. "F L G 1927""Castor" [1984.2022.000.000], Griggs, Frederick LandseerArtist and Role: Griggs, Frederick Landseer,Extent: plate 13.5 x 12.
Globalization and Politics from Alexandre Kojève to Eric Weil
No full textIn this essay, I provide an analysis of Alexandre Kojève’s «état universel et
homogène» and Eric Weil’s «état mondial». In particular, I consider how these
very different historical-political paradigms can help us to reflect on the end of
modernity and on the current effects of globalization
G. Radet. Notes critiques sur thistoire dt Alexandre
No full textGraindor Paul. G. Radet. Notes critiques sur thistoire dt Alexandre. In: Revue belge de philologie et d'histoire, tome 6, fasc. 3-4, 1927. pp. 855-857
Reply to Israel Carmi (2002): “Are the 14C Dates of the Dead Sea Scrolls Affected by Castor Oil Contamination?”
No full textThe Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
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