The stability of shallow spherical shells under concentrated load

Effect of load area on deformation of clamped spherical cap and behavior of transition from axisymmetric to asymmetric deflection shape

Constraining Dark Matter Interactions with Pseudoscalar and Scalar Mediators Using Collider Searches for Multi-jets plus Missing Transverse Energy

The mono-jet search, looking for events involving missing transverse energy (MET) plus one or two jets, is the most prominent collider dark matter search. We show that multi-jet searches, which look for MET plus two or more jets, are significantly more sensitive than the mono-jet search for pseudoscalar- and scalar-mediated interactions. We demonstrate this in the context of a simplified model with a pseudoscalar interaction that explains the excess in GeV energy gamma rays observed by the Fermi Large Area Telescope. We show that multi-jet searches already constrain a pseudoscalar interpretation of the excess in much of the parameter space where the mass of the mediator (mA) is more than twice the dark matter mass (mDM). With the forthcoming run of the LHC at higher energies, the remaining regions of the parameter space where mA>2mDM will be fully explored. Furthermore, we highlight the importance of complementing the mono-jet final state with multi-jet final states to maximise the sensitivity of the search for the production of dark matter at colliders.Comment: 7 pages, 2 figures. v2: Updated to match the journal versio

Managed retreat: a rare and paradoxical success, but yielding a dismal prognosis

Managed retreat (MR) involves permanent resettlement of existing households and communities away from areas at risk, here coastal flood risk. On post-Sandy Staten Island, New York, where MR has been successful, our research findings from interviews and a focus group of key stakeholders and commentators indicate there are very significant political impediments as well as financial constraints to MR programs being successful without the experience of a disaster and a repetitive sequence of hazardous events. Pre-disaster and long-term plans for reducing risks in such vulnerable areas are easy to advocate but not to implement. Many coastal locations globally will need some form of MR, where current risk is very high as a legacy of past decisions and where many communities will not be defendable against the expected future sea level rise. With leadership and community commitment locally MR agendas can and should be pursued: the optimistic scenario. But success appears likely only in the aftermath of a major disaster. This suggests strongly that we may have to await those inevitable disasters, and then be ready to act, rather than vice versa: a worrying conclusion and a dismal prognosis

The immunohistochemical analysis of fibronectin, collagen type III, laminin, and cytokeratin 5 in putrified skin

Fibronectin, collagen type III, laminin, and cytokeratin 5 were visualized in normal skin and in skin showing early or advanced signs of autolytic decomposition to prove whether the immunohistochemical analysis of these antigens can provide useful information for an age-estimation of skin wounds obtained from putrified corpses. In cases with early signs of decomposition (visible course of veins, greenish discoloration) and without microscopic alterations like relaxation of the epidermal cell layers or destruction of the blood vessel structures, the staining pattern was identical to that found in normal, non-putrefied skin. In skin already showing microscopic alteration of the tissue structure, fibronectin and collagen type III could not be localized unambiguously. The distribution of laminin and cytokeratin 5, however, was well preserved. In advanced putrefied skin no reliable staining results could be obtained for fibronectin, collagen type III, and laminin. Even though cytokeratin 5 was still detectable in remnants of decomposition-resistant skin appendages, no information useful for an age-estimation of skin wounds can be obtained due to the autolytic detachment of the epidermal layers

Use of Dynamic Scale Models to Determine Launch Vehicle Characteristics. Volume 2 - Experimental Investigation Final Report

Determination of free vibration characteristics in conical and cylindrical shell structures of Saturn S-2 stage using dynamic scale models, Vol.

Alveolar macrophages and the diagnosis of drowning

In the present study, we examined the number of alveolar macrophages in lung tissue from 17 cases of fresh water drowning, 22 cases of acute death and 6 cases of lung emphysema. When counting only the number of alveolar macrophages per alveolus without consideration of the alveolar size we found no relevant differences between the groups investigated. To exclude any influence of the alveolar size on the results the surface density of the alveolar macrophages and interstitial tissue was estimated and compared in the different groups. In cases of drowning, the lungs showed significantly lower values in both categories. The ratio of ‘alveolar macrophages/interstitial tissue’ was also reduced in cases of drowning in comparison to the other groups, however, without significant differences. These morphometrical results characterizing the ‘emphysema aquosum’ with almost ‘empty’ and dilated alveoli could be explained by a wash-out effect of the drowning fluid leading to a partial removal of the macrophages from the alveoli. This hypothesis was confirmed by the detection of alveolar macrophages in the drowning froth by immunohistochemical analysis. Even though alveolar macrophages were unambiguously identified in advanced putrefied lungs in HE-stained sections as well as by immunohistochemical staining, an estimation of the number of these cells cannot provide further information for the diagnosis of drowning in putrefied corpses due to the autolytic destruction of the lung architecture providing no reliable values

Aerobic and Anaerobic Respiration: Inquiry Compared to Traditional Pedagogical Approaches

This article discusses and compares two approaches to teaching students about aerobic and anaerobic respiration. One approach was to have students take part in a common cookbook activity where a preset procedure is followed. In the second approach, students completed the same activity, th but in a more inquiry-oriented fashion. Each approach was implemented in two 10 grade classes. Students experiencing the inquiry approach were observed spending more time discussing the targeted concepts, and they performed better on the end-of-unit test. This article addresses National Science Education Standards A, C, and G and Iowa Teaching Standards 1, 2, 3, 4, and 5

Temperature perturbation model of the opto-galvanic effect in CO2-laser discharges

A detailed discharge model of the opto-galvanic effect in molecular laser gas mixtures is developed based on the temperature perturbation or discharge cooling mechanism of Smith and Brooks (1979). Excellent agreement between the model and experimental results in CO2 laser gas mixtures is obtained. The model should be applicable to other molecular systems where the OGE is being used for laser stabilisation and as a spectroscopic tool

Can a charged ring levitate a neutral, polarizable object? Can Earnshaw's Theorem be extended to such objects?

Stable electrostatic levitation and trapping of a neutral, polarizable object by a charged ring is shown to be theoretically impossible. Earnshaw's Theorem precludes the existence of such a stable, neutral particle trap.Comment: 11 pages, 1 figur