Geological-hydrogeochemical characteristics of a "silver spring" water source (the Lozovy ridge)

Geological and hydrogeological characteristics of the Lozovy ridge (Southern Primorye) are studied, as far as karst phenomena are widely distributed within its boundaries. Water-bearing rocks of the karst water source "Silver Spring" ("Serebryany Klyuch"), which is located near the bottom of the "Bear's fang" ("Medvezhiy klyk") cave, are investigated. It is found that karst rocks are presented by calcite (CaCO[3]), and an accessory mineral is barite (BaSO[4]). It is determined that among the trace elements forming the composition of carbonate water-bearing rocks the maximum concentrations are typical for Sr, Ba, Fe, Al, Za, Mn, Cu, and Ni. Also, the chemical composition of the waters taken from the "Silver Spring" water source is studied. These waters are fresh, hydrocarbonate, calcium, and weakly alkaline. Among the elements of the spring, such elements as Sr, Ba, Fe, Al, Zn, Mn, Cu, and Ni have the maximum concentration. The other elements have concentrations less than 1 [mu]g/l

Sex and the Single Gametophyte: Revising the Homosporous Vascular Plant Life Cycle in Light of Contemporary Research

Homosporous vascular plants are typically depicted as extreme inbreeders, with bisexual gametophytes that produce strictly homozygous sporophytes. This view is promulgated in textbook life cycles despite ample evidence that natural populations of most species regularly outcross. We review research on a variety of mechanisms, including genetic load, asynchronous production of eggs and sperm, and pheromonal control of gamete production, that actively promote heterozygosity in ferns and lycophytes. Evolution of the land plants cannot be reconstructed without accurate depictions of the unique life cycle that has helped make ferns the second most diverse lineage of vascular plants on Earth. With revised illustrations and definitions, we provide scientists, educators, and students with a contemporary understanding of fern and lycophyte reproduction, revealing them as evolutionarily dynamic and exploiting a wide range of mating systems

Results of UBV Photoelectric Observations of the Early-Type Eclipsing Binary System XZ Cep

Results of the three-colour photoelectric observation of the close binary system XZ Cep, obtained at the Abastumani Astrophysical observatory, are presented.Comment: 23 pages, 3 figures, 1 tebl

Understanding the UK hospital supply chain in an era of patient choice

Author Posting © Westburn Publishers Ltd, 2011. This is a post-peer-review, pre-copy-edit version of an article which has been published in its definitive form in the Journal of Marketing Management, and has been posted by permission of Westburn Publishers Ltd for personal use, not for redistribution. The article was published in Journal of Marketing Management, 27(3-4), 401 - 423, doi:10.1080/0267257X.2011.547084 http://dx.doi.org/10.1080/0267257X.2011.547084The purpose of this paper is to investigate the UK hospital supply chain in light of recent government policy reform where patients will have, inter alia, greater choice of hospital for elective surgery. Subsequently, the hospital system should become far more competitive with supply chains having to react to these changes as patient demand becomes less predictable. Using a qualitative case study methodology, hospital managers are interviewed on a range of issues. Views on the development of the hospital supply chain in different phases are derived, and are used to develop a map of the current hospital chain. The findings show hospital managers anticipating some significant changes to the hospital supply chain and its workings as Patient Choice expands. The research also maps the various aspects of the hospital supply chain as it moves through different operational phases and highlights underlying challenges and complexities. The hospital supply chain, as discussed and mapped in this research, is original work given there are no examples in the literature that provide holistic representations of hospital activity. At the end, specific recommendations are provided that will be of interest to service to managers, researchers, and policymakers

Analysis of the infrared spectra of the peculiar post-AGB stars EPLyr and HD52961

Aim: We aim to study in detail the peculiar mineralogy and structure of the circumstellar environment of two binary post-AGB stars, EPLyr and HD52961. Both stars were selected from a larger sample of evolved disc sources observed with Spitzer and show unique solid-state and gas features in their infrared spectra. Moreover, they show a very small infrared excess in comparison with the other sample stars. Methods: The different dust and gas species are identified on the basis of high-resolution Spitzer-IRS spectra. We fit the full spectrum to constrain grain sizes and temperature distributions in the discs. This, combined with our broad-band spectral energy distribution and interferometric measurements, allows us to study the physical structure of the disc, using a self-consistent 2D radiative-transfer disc model. Results: We find that both stars have strong emission features due to CO_2 gas, dominated by ^{12}C^{16}O_2, but with clear ^{13}C^{16}O_2 and even ^{16}O^{12}C^{18}O isotopic signatures. Crystalline silicates are apparent in both sources but proved very hard to model. EP Lyr also shows evidence of mixed chemistry, with emission features of the rare class-C PAHs. Whether these PAHs reside in the oxygen-rich disc or in a carbon-rich outflow is still unclear. With the strongly processed silicates, the mixed chemistry and the low ^{12}C/^{13}C ratio, EP Lyr resembles some silicate J-type stars, although the depleted photosphere makes nucleosynthetic signatures difficult to probe. We find that the disc environment of both sources is, to a first approximation, well modelled with a passive disc, but additional physics such as grain settling, radial dust distributions, and an outflow component must be included to explain the details of the observed spectral energy distributions in both stars.Comment: 14 pages, accepted for publication by A&

Aquaponics as an educational tool

This chapter provides an overview of possible strategies for implementing aquaponics in curricula at different levels of education, illustrated by case studies from different countries. Aquaponics can promote scientific literacy and provide a useful tool for teaching the natural sciences at all levels, from primary through to tertiary education. An aquaponics classroom model system can provide multiple ways of enriching classes in Science, Technology, Engineering and Mathematics (STEM), and the day-to-day maintenance of an aquaponics can also enable experiential learning. Aquaponics can thus become an enjoyable and effective way for learners to study STEM content, and can also be used for teaching subjects such as business and economics, and for addressing issues like sustainable development, environmental science, agriculture, food systems, and health. Using learner and teacher evaluations of the use of aquaponics at different educational levels, we attempt to answer the question of whether aquaponics fulfils its promise as an educational tool

Проектирование системы электроснабжения машиностроительного завода

Обоснование и расчет системы электроснабжения предприятия машиностроения. Объект исследования: цех твердой изоляции машиностроительного завода. Цель: проектирование системы электроснабжения предприятия. Актуальность определяет проблема рационального электроснабжения предприятий, в данном случае машиностроительного завода. В ходе работы выполнен расчет электрических нагрузок завода и заданного цеха, выбор оборудования, проверка соответствия в разных режимах работы.Justification and calculation of the power supply system of the machine-building enterprise. Object of investigation: workshop of solid insulation of a machine-building plant. Purpose: design of the power supply system of the enterprise. Urgency is determined by the problem of rational power supply of enterprises, in this case, a machine-building plant. In the course of the work, the calculation of the electrical loads of the plant and the given workshop, the choice of equipment, and the verification of compliance in different operating modes were carried out