POROSITY: III. WATER AS AN ABSORPTION LIQUID

Classes of absorption method .—The ordinary immersion method has been shown by previous investigators to be unreliable. Simple immersion in low vacuo without boiling is also shown theoretically to be unreliable. An analysis of the results of previous investigators indicates the presence of unsuspected sources of error. Effect of adsorbed gases upon dry weights of test pieces .—Dry air is shown to be without appreciable influence. Depending upon the humidity of the atmosphere, adsorbed water vapor may cause errors up to 2 per cent in the porosity value. Perfectly dry fired clay will remove water from conc. H₂SO₄, and from fused CaCl₂. Saturation by boiling at atmospheric pressure .—A one hour's (and in one instance a 5 hours') boiling failed to saturate completely. On continued boiling the saturated weight increases linearly with the time and this in spite of the fact that appreciable quantities of dissolved materials are removed from the test piece by the hot water. This result is shown to be due to a gradual and continuous rehydration of the clay by the hot water. The error from this factor may amount to as much as 3% and the error from dissolved materials to as much as 2%, during a 3 hours' boiling. The nature of the dissolved material was determined. Method of cooling the test piece .—It is recommended that the test piece be kept in a closed vessel over 95% sulphuric acid for several hours before its dry weight is taken. Saturation procedure .—A vacuum method is described in which water may be employed as the saturation liquid under conditions where the above sources of error are reduced to a minimum. The method is not however recommended as a primary standard. Necessity of a soaking period .—It is shown from theoretical considerations that a soaking period is necessary and methods are given for calculating and for measuring the minimum soaking period required for a given test piece and a given liquid of known penetrativity.     

Individual differences in output variability as a function of job complexity.

The hypothesis was tested that the standard deviation of employee output as a percentage of mean output (SDp) increases as a function of the complexity level of the job. The data examined were adjusted for the inflationary effects of measurement error and the deflationary effects of range restriction on observed SDp figures, refinements absent from previous studies. Results indicate that SDp increases as the information-processing demands (complexity) of the job increase; the observed progression was approximately 19%, 32%, and 48%, from low to medium to high complexity nonsales jobs, respectively. SDp values for sales jobs are considerably larger. These findings have important implications for the output increases that can be produced through improved selection. They may also contribute to the development of a theory of work performance. In addition, there may be implications in labor economics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatal Campylobacter jejuni infection in a patient splenectomised for thalassaemia

A 35 year old man with a fatal Campylobacter jejuni infection is described. He had HbE/beta zero thalassaemia and had undergone splenectomy nine months previously for hypersplenism; he also had chronic hepatitis C infection. He presented with high grade fever but no gastrointestinal symptoms and rapidly progressed to septicaemic shock and hepatic encephalopathy despite treatment with penicillin, gentamicin, and, later, chloramphenicol and ceftazidime. Only one case of Campylobacter jejuni septicaemia occurring post-splenectomy has been reported previously, also in an iron overloaded thalassaemia patient. Unusual Gram negative bacilli must be covered by the chosen antibiotic regimen when splenectomised thalassaemic patients present with high grade fever.     

Sicherheit und rechtliche Herausforderungen in Bezug auf Cloud Computing und Kritische Infrastruktur-IT

The prevalence of machine-to-machine (M2M) will continue to increase because of the connection and interlinking of services in the domain of critical infrastructures (e.g. “smart grids”, traffic management or surveillance systems). This is leading to a constant rise of required computational and storage resources. As field systems typically offer only limited computing and storage capabilities and as many applications require a global view to integrated data from various devices, a natural location to store data and perform analysis tasks is in the Cloud, where an abundance of flexible resources can be used. However, this results in a number of security and privacy challenges in combination with some legal and technical considerations that need to be addressed. In this paper, we will investigate and categorize the above challenges associated with using the Cloud in a critical infrastructure and M2M context.