Mitigation of blast effects on existing structures in austere environments

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 52-53).Military commanders in austere environments often face challenges in setting up headquarters buildings that offer protected areas for sensitive equipment. One solution to this problem is simply to build a structure that can be used for this purpose. This method can prove to be difficult in that it could either require large amounts of prefabricated concrete, heavy earthmoving equipment, or a significant effort in digging by hand. Clearly, all of these options are unsuitable for constructing a headquarters building that would be occupied for a short time or if the resources required were unavailable. Another solution to this problem is to simply occupy an existing structure. This method is extremely favorable with respect to resources required; with the major drawback being that at times existing structures may offer limited protection from hostile forces. Since the US Army often has overwhelming firepower when compared to contemporary threats, many times hostile forces will resort to suicide or remotely detonated explosive devices when attempting to destroy or damage structures of this type. In order to determine the feasibility of mitigating this threat, this paper will explore the effects of various explosive devices on model building types that may be found in austere environments, and explore the effects of possible reinforcement schemes in mitigating blast threats to these structures.by Andrew J. Maxa.S.M

Development of a versatile laboratory experiment to teach the metabolic transformation of hydrolysis

In this paper we describe an easy, reliable, versatile and inexpensive laboratory experiment to teach the metabolic transformation of hydrolysis to Pharmacy students. The experiment does not require the sacrifice of any experimental animal, or any work with organs or tissues, and so can be implemented in a typical university chemistry laboratory. We used acetylsalicylic acid (ASA), hexyl salicylate (HS) and two enzymes, a lipase and an esterase. Since both ASS and HS liberate salicylic acid (SA) upon hydrolysis, students can evaluate the different enzymatic transformations by monitoring the amount of SA liberated. The learning outcomes are an enhanced student understanding of: (1) the process of hydrolysis; (2) the application of enzymatic transformations of molecules from food to xenobiotics; (3) the differences between the general specificity of substrate of both enzymes; (4) the concepts of the lipophilic pocket; (5) the catalytic triad and its regioselectivity in relation to the ester bond. A questionnaire was administered to participating students at three points in time: at the beginning of the module, after enzymatic hydrolysis was taught in class, and after the laboratory experiment. From an analysis of the questionnaire data we conclude that this practical helped Pharmacy students to understand these concepts

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

Results are presented from searches for the standard model Higgs boson in proton–proton collisions at √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb^(−1) at 7 TeV and 5.3 fb^(−1) at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W^+W^−, τ^+τ^−, and bb. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3±0.4(stat.)±0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one

Simulated environment of EPD and PDM in education

This article contains a description of relationship between EPD and PDM environment and way of education methodology

Using Cosmos FloWorks to Design the Differentially Pumped Chamber

Environmental scanning electron microscope creates new possibilities in the field of examination various types of specimens and their phases. Using Cosmos FloWorks to design the differentially pumped chamber enable make optimal shape of this chamber, which is very important for god function of VP-SEM

System COSMOS FloWorks educated in a consequence with electronic product definition

This article show practical advantages of COSMOS FloWorks and possibilities of their application to design of optimized differentially pumped chamber applied in environmental scanning electron microscop