Multichannel cold collisions between metastable Sr atoms

We present a multichannel scattering calculation of elastic and inelastic cold collisions between two low-field seeking, metastable ^{88}Sr [(5s5p) ^3P_2] atoms in the presence of an external magnetic field. The scattering physics is governed by strong anisotropic long-range interactions, which lead to pronounced coupling among the partial waves of relative motion. As a result, nonadiabatic transitions are shown to trigger a high rate of inelastic losses. At relatively high energies, T > 100 mkK, the total inelastic collision rate is comparable with the elastic rate. However, at lower collisional energy, the elastic rate decreases, and at T ~ 1mkK, it becomes substantially smaller than the inelastic rate. Our study suggests that magnetic trapping and evaporative cooling of ^{88}Sr [(5s5p) ^3P_2] atoms, as well as ^{40}Ca [(4s4p) ^3P_2], in low-field seeking states will prove difficult to achieve experimentally.Comment: 4 pages, Latex, Submitte

Galilei invariant theories. I. Constructions of indecomposable finite-dimensional representations of the homogeneous Galilei group: directly and via contractions

All indecomposable finite-dimensional representations of the homogeneous Galilei group which when restricted to the rotation subgroup are decomposed to spin 0, 1/2 and 1 representations are constructed and classified. These representations are also obtained via contractions of the corresponding representations of the Lorentz group. Finally the obtained representations are used to derive a general Pauli anomalous interaction term and Darwin and spin-orbit couplings of a Galilean particle interacting with an external electric field.Comment: 23 pages, 2 table

Bering Strait transports from satellite altimetry

TOPEX/POSEIDON altimetry data are used to compute sea level slopes across the Bering Strait and associated geostrophic transport anomalies through the strait during ice-free periods from 1992 to 2002. The satellite turning latitude near 66N is just north of the strait, allowing us to use data from seven nearly zonal altimeter tracks close to the strait and to provide estimates of mean slopes, geostrophic currents and water transports approximately every 1.5 days. The altimeter-derived transport anomalies far exceed the mean value and are in good agreement with those derived from in situ observations. Comparison to wind data from a nearby meteorological station in Uelen, Russia, shows that computed transport anomalies correlate well with strong along-strait winds and less so with winds from other directions, thus making the transport predictions from winds alone more successful in seasons with strong and persistent meridional winds

Competitive reactions method in electrochemistry. A new tool for investigating the anodic intermediates reactivity

Some application features of the competitive reactions method (C.R.M.) for anodically generated agents have been considered. Quantitative characteristics of the (RO)3P, (RO)2 POSiMe3, (EtO)2 PONa, and I2 electrochemically induced intermediates have been presented. It is discussed how to apply the obtained information for stating the nature of respective species. © 1989

Combined Indexing Method In NoSQL Databases

Any system must process requests quickly. This is one of the main conditions for a successful system. Higher data processing rates come along with new technologies. An example is 5G technology, which allows data to be exchanged at speed of up to 100 Mbps for downloads and up to 50 Mbps for uploads. The operation of the database depends on many factors, including the characteristics of the server, the number of requests to the server and the requests themselves. Improperly worded queries can degrade the speed of the system in general. The situation can be corrected by indexing, which allows you to increase the speed of searching for information in the database itself

Modification of hashing algorithm to increase rate of operations in NOSQL databases

Optimizing the database is quite a difficult task and involves solving a range of interrelated problems. This is to ensure acceptable performance and functionality of the database, user convenience, optimization of resources consumed, for example, by the criterion of minimizing memory costs and maximizing network usage. The most important aspect of optimization is to increase the performance of the database. To increase the performance of the database, you can use general methods to increase the speed of programs, such as increasing the power of hardware, operating system configuration, optimizing the structure of external media and placing the database on them, and others. In addition, special tools are used to optimize the database, already built into. In particular, most modern relational databases have a special component - query optimizer, which allows you quickly and efficiently process selection requests and data manipulation requests. The most common way to optimize database performance is to compress the database. It optimizes the placement of database objects on external media and the return of free disk space for future use. The most common compression technology is based on differences, when a value is replaced by information about its differences from the previous value. Another type of compression technology is based on hierarchical data compression. The essence is in the encoding of individual characters with bit strings of different lengths. Indexing and hashing are used to speed up access to database data at the request of users. Indexing speeds up search operations in the database, as well as other operations that require search: delete, edit, sort. The purpose of using indexing is to speed up data retrieval by reducing the number of disk I / O operations. Another common way to organize records and access data is hashing, a technology for quick direct access to a database record based on a given value of some record field, usually a key one

Longitudinal trajectories of blood lipid levels in an ageing population sample of Russian Western-Siberian urban population

This study investigated 12-year blood lipid trajectories and whether these trajectories are modified by smoking and lipid lowering treatment in older Russians. To do so, we analysed data on 9,218 Russian West-Siberian Caucasians aged 45-69 years at baseline participating in the international HAPIEE cohort study. Mixed-effect multilevel models were used to estimate individual level lipid trajectories across the baseline and two follow-up examinations (16,445 separate measurements over 12 years). In all age groups, we observed a reduction in serum total cholesterol (TC), LDL-C and non-HDL-C over time even after adjusting for sex, statin treatment, hypertension, diabetes, social factors and mortality (P 60 years at baseline). In smokers, TC, LDL-C, non-HDL-C and TG decreased less markedly than in non-smokers, while HDL-C decreased more rapidly while the LDL-C/HDL-C ratio increased. In subjects treated with lipid-lowering drugs, TC, LDL-C and non-HDL-C decreased more markedly and HDL-C less markedly than in untreated subjects while TG and LDL-C/HDL-C remained stable or increased in treatment naïve subjects. We conclude, that in this ageing population we observed marked changes in blood lipids over a 12 year follow up, with decreasing trajectories of TC, LDL-C and non-HDL-C and mixed trajectories of TG. The findings suggest that monitoring of age-related trajectories in blood lipids may improve prediction of CVD risk beyond single measurements