Cyclic cocycles on twisted convolution algebras

We give a construction of cyclic cocycles on convolution algebras twisted by gerbes over discrete translation groupoids. For proper \'etale groupoids, Tu and Xu provide a map between the periodic cyclic cohomology of a gerbe-twisted convolution algebra and twisted cohomology groups which is similar to a construction of Mathai and Stevenson. When the groupoid is not proper, we cannot construct an invariant connection on the gerbe; therefore to study this algebra, we instead develop simplicial techniques to construct a simplicial curvature 3-form representing the class of the gerbe. Then by using a JLO formula we define a morphism from a simplicial complex twisted by this simplicial curvature 3-form to the mixed bicomplex computing the periodic cyclic cohomology of the twisted convolution algebras. The results in this article were originally published in the author's Ph.D. thesis.Comment: 39 page

Groupoids and an index theorem for conical pseudo-manifolds

We define an analytical index map and a topological index map for conical pseudomanifolds. These constructions generalize the analogous constructions used by Atiyah and Singer in the proof of their topological index theorem for a smooth, compact manifold $M$. A main ingredient is a non-commutative algebra that plays in our setting the role of $C_0(T^*M)$. We prove a Thom isomorphism between non-commutative algebras which gives a new example of wrong way functoriality in $K$-theory. We then give a new proof of the Atiyah-Singer index theorem using deformation groupoids and show how it generalizes to conical pseudomanifolds. We thus prove a topological index theorem for conical pseudomanifolds

Derivation and measurement of the M/# in spectral hole burning media

We demonstrate 10 plane wave holograms angularly multiplexed at one frequency channel in spectral hole burning medium. We show that the M/# is still a valid system metric and the measured M/# in one frequency channel is about 0.01

Foamed glass-ceramic materials based on oil shale by-products

The feasibility and features of the production of foamed glass-ceramic materials based on oil shale ash were investigated. The optimal regime of synthesis found involved the following steps: glass fusion at 1400 °C, preparation of the glass powders and blending with the foaming agent. The foaming was carried out at 900 to 920 °C with a further one-stage crystallization at 790 to 820 °C. It was noted that the admixture of calcium carbonate, as a foaming agent, changed the phase composition of the resulting glass-ceramics by an increased rate of the crystallization process and the intensive formation of gehlenite simultaneously with diopside

ЭТАПЫ РАЗВИТИЯ СЕЛЕКЦИИ ОГУРЦА В ЛАБОРАТОРИИ СЕЛЕКЦИИ ОВОЩНЫХ КУЛЬТУР ПРИДНЕСТРОВСКОГО НИИ СЕЛЬСКОГО ХОЗЯЙСТВА

The main stages of development of research on cucumber breeding during more than 70 years in the Institute, and, in particular, in the laboratory of breeding are described.Приведены основные этапы развития селекционных исследований по огурцу за более чем 70,ти летний период работы института, и, в частности, в лаборатории селекции

REMOCIÓN DE PLOMO DE SOLUCIONES ACUOSAS POR TITANATO DE POTASIO DOPADO CON SÍLICE

This paper is related to elimination of Pb2+ ions from aqueous solutions by adsorption in potassium tetratitanate doped with silica. The adsorbent was prepared in the form of granules with pastes of potassium polytitanate (45 %), powdered Pyrex® glass (5 %) and potato starch (50 %), which were extruded and thermally treated at 1100 ºC. The structural characteristic of the granulated adsorbent allows reducing the Pb concentration, from the solutions eluted through an adsorption column, to levels below the requirement of national standards. The effects of the time of saturation of the adsorbent and the pH of the solution were also investigated on the effectiveness of the adsorption of Pb. The mechanism of lead adsorption, by the developed adsorbent, is considered as a combination of adsorption, ion-exchange and co-precipitation processes. It is also shown that the lead-saturated adsorbent could be utilized to produce high-strength non-dangerous ceramic materials.Este trabajo se refiere a la remoción de iones de Pb2+ de soluciones acuosas mediante adsorción en tetratitanato de potasio dopado con sílice. El adsorbente se preparó en forma de gránulos con pastas de polititanato de potasio (45%), vidrio Pyrex® (5%) y almidón de papa (50%), extruídas y tratadas térmicamente a 1100°C. Las características estructurales del adsorbente granular, permiten la remoción de plomo de soluciones acuosas eluídas a través de una columna de adsorción, a niveles inferiores a los requerimientos de las normas mexicanas. También se estudiaron los efectos del tiempo de saturación del adsorbente y el valor del pH de solución sobre la efectividad de remoción del plomo. El mecanismo de remoción de Pb, mediante el uso del adsorbente desarrollado, se considera como una combinación de procesos de adsorción, intercambio iónico y co-precipitación. También se muestra que el adsorbente saturado con iones de plomo (Pb2+) puede reutilizarse para producir un material cerámico no peligroso y de alta resistencia mecánica

Wastewater Treatment from Lead and Strontium by Potassium Polytitanates: Kinetic Analysis and Adsorption Mechanism

The reduction of heavy and radioactive metal pollution of industrial wastewater remains a vital challenge. Due to layered structure and developed surface, potassium polytitanate had potential in becoming an effective sorbent for metal extraction from wastewater in the presented paper. On the basis of the different sorption models, this paper studied the mechanism of Pb2+ and Sr2+ cation extraction from aqueous solution by non-crystalline potassium polytitanate produced by molten salt synthesis. The ion exchange during metal extraction from model solutions was proven by kinetic analysis of ion concentration change, electronic microscopy, and X-ray fluorescence analysis of sorbent before and after sorption, as well as by theoretical modeling of potassium, lead, and strontium polytitanates. The sorption was limited by the inner diffusion in the potassium polytitanate (PPT) interlayer space, as was shown using the Boyd diffusion model. The sorption processes can be described by Ho and McKay’s pseudo-second-order model compared to the Lagergren pseudo-first-order model according to kinetic analysis. It was found that the ultimate sorption capacity of synthesized sorbent reached about 714.3 and 344.8 (ions mg/sorbent grams) for Pb2+ and Sr2+ ions, respectively, which was up to four times higher than sorption capacity of the well-known analogues. Therefore, the presented study showed that potassium polytitanate can be considered as a promising product for industry-scaled wastewater purification in practice

Production tests of birch wood drying technology with stepless modes

Ученые-сушильщики все чаще обращают свое внимание на вопросы сушки древесины различных лиственных пород. Это связано как с отраслевыми потребностями лесоперерабатывающей промышленности (истощение запасов хвойной древесины), так и с отсутствием эффективных технологий переработки лиственной древесины. Среди прочих лиственных пород береза привлекает особое внимание из-за огромных запасов и физико-механических показателей. В последние годы довольно широкое применение получили так называемые бесступенчатые режимы сушки различных пород древесины, но для березы данный тип режимов не применялся. Проведенные в УГЛТУ теоретические исследования сушки березовых пиломатериалов бесступенчатыми режимами позволили надеяться на благоприятные результаты испытаний данной технологии в условиях реального производства, которые и были проведены в условиях производства в Свердловской области. Были использованы лесосушильные камеры MGR-50 (Режевской леспромхоз г. Реж) и УРАЛ-30 (ООО «НИКРЕС» г. Первоуральск). Благодаря проведенным экспериментам получены удачные результаты промышленной проверки. Во-первых, достигнуто реальное снижение продолжительности сушки и брака при ее проведении. Во-вторых, бесступенчатый режим позволяет повышать качество сушки за счет гарантированного соблюдения допуска на конечную влажность древесины с большим запасом. Нормативные режимы сушки предприятий позволяют получить конечные внутренние напряжения при сушке не выше II категории качества, хотя для снижения величины напряжений применяется влаготеплообработка. В то же время при применении бесступенчатых режимов влаготеплообработка не применяется, но внутренние напряжения при сушке существенно меньше и соответствуют в основном I категории качества.Drying scientists increasingly turn their attention to the issues of drying wood of various hardwoods. This is due to both the industry needs of wood processing industry (depletion of softwood stocks) so the lack of effective technologies for recycling hardwood. Among other hardwoods birch attracts special attention due to its huge reserves of wood and physical and mechanical properties. In recent years, so-called stepless drying modes of various wood have become been widely used, but this type of mode has not been used for birch. Theoretical studies of drying birch lumber by stepless modes carried out at USFEU allowed us to hope for favorable test results of this technology in real production conditions. These experiments were carried out under production conditions in the Sverdlovsk region. The wood drying chambers MGR-50 (Rezhevsky forestry enterprise, Rezh) and URAL-30 (LLC NIKRES, Pervouralsk) were used. Due to the conducted experiments, successful results of industrial testing were obtained. Firstly, a real reduction in drying time and rejection during its implementation has been achieved. Secondly, the stepless drying mode allows you to improve drying quality due to guaranteed compliance with the tolerance to the fi nal moisture wood moisture tolerance with a large margin. Standard drying modes of enterprises make it possible to obtain fi nal internal stresses during drying not higher the II quality category, although moisture and heat treatment is used to reduce the magnitude of stresses. At the same time, when using stepless modes, moisture and heat treatment is not used, but the internal stresses during drying are signifi cantly less and correspond mainly to the I quality category