Space shuttle launch vehicle performance trajectory, exchange ratios, and dispersion analysis

A baseline space shuttle performance trajectory for Mission 3A launched from WTR has been generated. Design constraints of maximum dynamic pressure, longitudinal acceleration, and delivered payload were satisfied. Payload exchange ratios are presented with explanation on use. Design envelopes of dynamic pressure, SRB staging point, aerodynamic heating and flight performance reserves are calculated and included

Use of Cryogenically Prepared Samples in the Scanning Electron Microscopic Study of Dry-to-Wet Transitions

Cryogenic preparation has been used to study changes that occur as a dry specimen undergoes hydration. Conventional techniques such as critical point drying or anhydrous fixation are unsuitable for studying such changes. Seed tissue, a dry moss and various foods were chosen to show dry-to-wet transitions that take place after wetting of the dry sample begins. Cryogenically prepared specimens have great potential, not only in the study of changes which occur during imbibition of one sample, but also in the study of samples with different moisture content

Beam Sensitivity of Globoid Crystals within Seed Protein Bodies and Commercially Prepared Phytates During X-Ray Microanalysis

Magnesium, potassium, calcium and phosphorus are stored in seed tissues in spherical particles called globoid crystals. The main component of globoid crystals is phytin, a salt of myo-inositol hexaphosphoric acid. Based on chemical similarity, commercially available phytates may be suitable standards for quantitative energy dispersive X-ray (EDX) microanalysis of globoid crystals. The stability of globoid crystals and commercial phytates was different when analyzed under identical conditions. Phytates in globoid crystals from Cucurbita maxima cotyledons, were relatively stable in the electron beam during EDX microanalysis at room temperature, but there was a loss of potassium. No loss of potassium occurred during analysis at low temperature, even with repeated analyses on the same spot. Commercial phytates showed considerable beam damage in the form of raised mounds at the sites of analyses. The extent of the damage was much reduced with analysis at low temperature. Although there was some variation in the peak-to-background ratios of potassium and sodium with various analytical conditions, there was no differential loss of potassium or sodium as occurred with EDX analysis of globoid crystals. Reasons for differences between in situ and isolated phytates are unclear. Provided analyses are carried out at low temperature, commercial phytates have potential as standards but further research is required to determine how to control moisture content during sample preparation and analysis

The effect of human land use change in the Hadley Centre attribution system

This is the final version. Available on open access from Wiley via the DOI in this recordAtmospheric Science Letters published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society. We have investigated the effects of land use on past climate change by means of a new 15-member ensemble of the HadGEM3-A-N216 model, usually used for event attribution studies. This ensemble runs from 1960 to 2013, and includes natural external climate forcings with the addition of human land use changes. It supports previously-existing ensembles, either with only natural forcings, or with all forcings (both anthropogenic and natural, including land use changes), in determining the contribution to the change in risk of extreme events made by land use change. We found a significant difference in near-surface air temperature trends over land, attributable to the effects of human land use. The main part of the signal derives from a relative cooling in Arctic regions which closely matches that of deforestation. This cooling appears to spread by polar amplification. A similar pattern of change is seen in latent heat flux trend, but significant rainfall change is almost entirely absent.Department for Business, Energy and Industrial Strategy, Met Office Hadley Centre Climate ProgrammeDepartment for Environment, Food and Rural AffairsEuropean CommissionUK‐China Research & Innovation Partnership Fund, Newton Fun

Cell Wall Wrinkling and Solute Leakage in Imbibing Squash and Carrot Seeds

Dry seeds placed in an aqueous solution take up water, swell, and leak potassium and a variety of other materials into the solution. It is likely that much of the potassium is from the cell walls. Neutron activation analysis was used to measure the concentration of potassium leaked from both squash embryos and carrot mericarps that had been soaked in solutions of different water content. The cell walls in dry seed tissues are often wrinkled, whereas imbibed tissues have smooth cell walls. Cryogenic preparation for scanning electron microscopy was used to study the degree of cell wall wrinkling in the seed tissues at different hydration levels. The aim of this study was to test the hypothesis that the degree of cell wall wrinkling was related to the leakage of potassium. It was found that the amount of potassium leaked into the soaking solutions was not directly related to the degree of wrinkling of the cell walls

New holomorphically closed subalgebras of C∗C^*-algebras of hyperbolic groups

We construct dense, unconditional subalgebras of the reduced group $C^*$-algebra of a word-hyperbolic group, which are closed under holomorphic functional calculus and possess many bounded traces. Applications to the cyclic cohomology of group $C^*$-algebras and to delocalized $L^2$-invariants of negatively curved manifolds are given

Calculus and heat flow in metric measure spaces and applications to spaces with Ricci bounds from below

This paper is devoted to a deeper understanding of the heat flow and to the refinement of calculus tools on metric measure spaces (X,d,m). Our main results are: - A general study of the relations between the Hopf-Lax semigroup and Hamilton-Jacobi equation in metric spaces (X,d). - The equivalence of the heat flow in L^2(X,m) generated by a suitable Dirichlet energy and the Wasserstein gradient flow of the relative entropy functional in the space of probability measures P(X). - The proof of density in energy of Lipschitz functions in the Sobolev space W^{1,2}(X,d,m). - A fine and very general analysis of the differentiability properties of a large class of Kantorovich potentials, in connection with the optimal transport problem. Our results apply in particular to spaces satisfying Ricci curvature bounds in the sense of Lott & Villani [30] and Sturm [39,40], and require neither the doubling property nor the validity of the local Poincar\'e inequality.Comment: Minor typos corrected and many small improvements added. Lemma 2.4, Lemma 2.10, Prop. 5.7, Rem. 5.8, Thm. 6.3 added. Rem. 4.7, Prop. 4.8, Prop. 4.15 and Thm 4.16 augmented/reenforced. Proof of Thm. 4.16 and Lemma 9.6 simplified. Thm. 8.6 corrected. A simpler axiomatization of weak gradients, still equivalent to all other ones, has been propose

Gender-specific Equations for Predicting Maximal Heart Rate in Exercise Stress Testing

Please view abstract in the attached PDF file