Lightweight magnesium-lithium alloys show promise

Evaluation tests show that magnesium-lithium alloys are lighter and more ductile than other magnesium alloys. They are being used for packaging, housings, containers, where light weight is more important than strength

The Ultimate Halo Mass in a LCDM Universe

In the far future of an accelerating LCDM cosmology, the cosmic web of large-scale structure consists of a set of increasingly isolated halos in dynamical equilibrium. We examine the approach of collisionless dark matter to hydrostatic equilibrium using a large N-body simulation evolved to scale factor a = 100, well beyond the vacuum--matter equality epoch, a_eq ~ 0.75, and 53/h Gyr into the future for a concordance model universe (Omega_m ~ 0.3, Omega_Lambda ~ 0.7). The radial phase-space structure of halos -- characterized at a < a_eq by a pair of zero-velocity surfaces that bracket a dynamically active accretion region -- simplifies at a > 10 a_eq when these surfaces merge to create a single zero-velocity surface, clearly defining the halo outer boundary, rhalo, and its enclosed mass, mhalo. This boundary approaches a fixed physical size encompassing a mean interior density ~ 5 times the critical density, similar to the turnaround value in a classical Einstein-deSitter model. We relate mhalo to other scales currently used to define halo mass (m200, mvir, m180b) and find that m200 is approximately half of the total asymptotic cluster mass, while m180b follows the evolution of the inner zero velocity surface for a < 2 but becomes much larger than the total bound mass for a > 3. The radial density profile of all bound halo material is well fit by a truncated Hernquist profile. An NFW profile provides a somewhat better fit interior to r200 but is much too shallow in the range r200 < r < rhalo.Comment: 5 pages, 3 figures, submitted to MNRAS letter

Radar mapping, archaeology, and ancient land use in the Maya lowlands

Data from the use of synthetic aperture radar in aerial survey of the southern Maya lowlands suggest the presence of very large areas drained by ancient canals for the purpose of intensive cultivation. Preliminary ground checks in several very limited areas confirm the existence of canals and raised fields. Excavations and ground surveys by several scholars provide valuable comparative information. Taken together, the new data suggest that Late Classic period Maya civilization was firmly grounded in large-scale and intensive cultivation of swampy zones

Rearing of all Male Tilapia (Oreochromis Niloticus) Fingerlings with Chicken Manure and Mixture of Chicken Manure and Commercial Diet in Fibre Glass Tank

Mono-sex population of Oreochromis niloticus fingerlings were collected from Nigerian Institute for oceanography and Marine Research Sapele station Hatchery and acclimatized for a week and randomly stocked at density of 300 fish/tank in nine fibre glass tank. The fingerling were fed daily 800h and 1600h with three different types of feed (Dry chicken manure, mixture of chicken manure and commercial diet, and commercial (coppens) only. Each treatment was replicated three times. The water quality parameters are within tolerant limit. The growth response in all the treatment wee generally satisfactory. Though treatment T3 Tanks fed with commercial diet only (coppens) had better growth performance compared with treatment T2 and T1, chicken manure and mixture of chicken manure and commercial diet respectively. The results demonstrate the feasibility of rearing all male tilapia (O. niloticus) fingerlings in fiber glass tanks

Coupled near and far field thermal plume analysis using finite element techniques

The use of the open cycle cooling process for thermal power plants requires significant effluent discharges into aquatic environments. Both engineering and environmental considerations require accurate prediction of resulting temperature distribution in the receiving waters. Most predictive models have looked at one of two distinct regions of the discharge--the near or the far field--to the neglect of the other.A methodology is developed in this work to combine the attributes of both near and far field models. A finite element far field code is utilized which calculates both the circulation and heat distribution over a large area of the domain. From the far field coarse grid, a semi-circular area is removed which corresponds to the near field region of the discharge. At the new edge of the domain, which represents the near-far field boundary, mass flux and temperature boundary conditions are specified which simulate both the discharge into and entrainment out of the domain resulting from the surface discharge jet.Initial verification and testing of the model's characteristics is carried out in a hypothetical idealized domain. A more realistic verification is done at two prototype sites by comparing calculated results to previously acquired field data. The two sites are Millstone Nuclear Power Station (on Long Island Sound near Waterford, Connecticut) operating with two units and Brayton Point Generating Station (in Mt. Hope Bay near Somerset, Massachusetts) operating with three units on open cycle (existing conditions) and with four units on open cycle (proposed future condition). These comparisons suggest that the model can realistically describe the far field flow patterns associated with near field mixing thus making the model a useful tool in evaluating induced circulations, the source of entrained organisms, etc. These flow patterns are a direct function of the near field entrainment and discharge distributions which are specified as model boundary conditions and are thus easily calibrated and, if necessary, modified. Comparison between measured and predicted temperatures indicates that the predicted lengths and areas of isotherms are similar to measured lengths and areas. Predicted temperatures generally indicate greater dispersion than measured temperatures thus leading to overprediction of intake recirculation. Also, because boundary conditions on the near-far boundary have been assumed constant, the shape of predicted isotherms is not as responsive to changes in ambient current direction (e.g., tidal variations) as the measurements indicate.Future efforts should emphasize grid and program coding refinement to improve computational efficiency, use of methods to reduce numerical dispersion and incorporation of time-varying near-far field boundary conditions

Chemically engineering ligand selectivity at the free fatty acid receptor 2 based on pharmacological variation between species orthologs

When it is difficult to develop selective ligands within a family of related G-protein-coupled receptors (GPCRs), chemically engineered receptors activated solely by synthetic ligands (RASSLs) are useful alternatives for probing receptor function. In the present work, we explored whether a RASSL of the free fatty acid receptor 2 (FFA2) could be developed on the basis of pharmacological variation between species orthologs. For this, bovine FFA2 was characterized, revealing distinct ligand selectivity compared with human FFA2. Homology modeling and mutational analysis demonstrated a single mutation in human FFA2 of C4.57G resulted in a human FFA2 receptor with ligand selectivity similar to the bovine receptor. This was exploited to generate human FFA2-RASSL by the addition of a second mutation at a known orthosteric ligand interaction site, H6.55Q. The resulting FFA2-RASSL displayed a &gt;100-fold loss of activity to endogenous ligands, while responding to the distinct ligand sorbic acid with pEC(50) values for inhibition of cAMP, 5.83 ± 0.11; Ca(2+) mobilization, 4.63 ± 0.05; ERK phosphorylation, 5.61 ± 0.06; and dynamic mass redistribution, 5.35 ± 0.06. This FFA2-RASSL will be useful in future studies on this receptor and demonstrates that exploitation of pharmacological variation between species orthologs is a powerful method to generate novel chemically engineered GPCRs

Landau Collision Integral Solver with Adaptive Mesh Refinement on Emerging Architectures

The Landau collision integral is an accurate model for the small-angle dominated Coulomb collisions in fusion plasmas. We investigate a high order accurate, fully conservative, finite element discretization of the nonlinear multi-species Landau integral with adaptive mesh refinement using the PETSc library (www.mcs.anl.gov/petsc). We develop algorithms and techniques to efficiently utilize emerging architectures with an approach that minimizes memory usage and movement and is suitable for vector processing. The Landau collision integral is vectorized with Intel AVX-512 intrinsics and the solver sustains as much as 22% of the theoretical peak flop rate of the Second Generation Intel Xeon Phi, Knights Landing, processor

Cod Liver Oil as a Source of Vitamin A

In the course of experiments having for their object the study of the properties of vitamin A with a view to its isolation, certain observations were made concerning the behavior of animals on various rations containing cod liver oil. It was noted that different samples of cod liver oil apparently vary markedly in vitamin A potency. Xerophthalmia has been produced in rats on diets containing as much as 3 per cent of cod liver oil. Synthetic rations containing cod liver oil evolve a penetrating odor resembling acrolein. When the cod liver oil is replaced with butter fat, this odor is not observed. It is possible that the failure of rats on diets containing certain samples of cod liver oil may be due to one or more of the following factors. 1. A decreased consumption of the diet clue to this decomposition product. 2. A destruction of vitamin A which runs parallel with the destruction of the cod liver oil. 3. Certain samples of cod liver oil are not as rich in vitamin A as supposed heretofore

The equivalence of fluctuation scale dependence and autocorrelations

We define optimal per-particle fluctuation and correlation measures, relate fluctuations and correlations through an integral equation and show how to invert that equation to obtain precise autocorrelations from fluctuation scale dependence. We test the precision of the inversion with Monte Carlo data and compare autocorrelations to conditional distributions conventionally used to study high-$p_t$ jet structure.Comment: 10 pages, 9 figures, proceedings, MIT workshop on correlations and fluctuations in relativistic nuclear collision