14 research outputs found
Extended defects in natural diamonds: Atomic Force Microscopy investigation
Surfaces of natural diamonds etched in high-pressure experiments in H2O, CO2
and H2O-NaCl fluids were investigated using Atomic Force Microscopy. Partial
dissolution of the crystals produced several types of surface features
including the well-known trigons and hillocks and revealed several new types of
defects. Besides well-known trigons and dissolution hillocks several new types
of defects are observed. The most remarkable ones are assigned to anelastic
twins of several types. The observation of abundant microtwins, ordering of
hillocks and presence of defects presumably related to knots of branched
dislocations suggests importance of post-growth deformation events on formation
of diamond microstructure. This work confirms previous reports of ordering of
extended defects in some deformed diamonds. In addition, the current work shows
that natural diamonds deform not only by dislocation mechanism and slip, but
also but mechanical twinning. The dominant mechanism should depend on
pressure-temperature-stress conditions during diamond transport from the
formation domain to the Earth surface.Comment: Submitted to special issue (1st European Mineralogical congress,
Frankfurt, Germany, September 2012) of European Journal of Mineralogy. 21
page, 9 figure
String versus Einstein frame in an AdS/CFT induced quantum dilatonic brane-world universe
AdS/CFT induced quantum dilatonic brane-world where 4d boundary is flat or de
Sitter (inflationary) or Anti-de Sitter brane is considered. The classical
brane tension is fixed but boundary QFT produces the effective brane tension
via the account of corresponding conformal anomaly induced effective action.
This results in inducing of brane-worlds in accordance with AdS/CFT set-up as
warped compactification. The explicit, independent construction of quantum
induced dilatonic brane-worlds in two frames: string and Einstein one is done.
It is demonstrated their complete equivalency for all quantum cosmological
brane-worlds under discussion, including several examples of classical
brane-world black holes. This is different from quantum corrected 4d dilatonic
gravity where de Sitter solution exists in Einstein but not in Jordan (string)
frame. The role of quantum corrections on massive graviton perturbations around
Anti-de Sitter brane is briefly discussed.Comment: LaTeX file, 24 pages, minor changes to match with published versio
Dry Residues of Sewage – a Promising Energy Fuel
По профилям кривых дифференциальной сканирующей калориметрии была
определена максимальная интенсивность теплового потока, а также эндотермические
и экзотермические эффекты горения остатков сточных вод (ОСВ). Иловые остатки сточных
вод имеют высокую зольность (более 50 %), что снижает значение низшей теплоты сгорания
в рабочем состоянии. Высокое содержание летучих веществ (более 80 %) обеспечивает раннее
зажигание при температуре 268 °C. Имея низкую температуру зажигания, они могут быть
перспективным добавочным топливом к углю после обогащения с целью существенного
снижения зольности и увеличения теплоты сгорания. Низкое значение индекса горения, равное
0,4×10–6, обусловлено низким значением максимальной скорости реакции, равной 13 %/мин,
и высокой температурой выгорания, равной 633 °C. Проведенные исследования показали, что
сжигание ОСВ не приводит к ухудшению условий эксплуатации топочных экранов в топках
котлов из-за
высокого содержания минералов в золе с высокой температурой плавления
(фосфаты железа и кальция). Высокое содержание фосфора в остатках сточных вод способствует
иммобилизации подвижного железа в фосфаты. Такой состав ОСВ будет способствовать
уменьшению мобильности тяжелых металлов в шлаковых и зольных остатках совместного
сжигания с углями при последующем долговременном хранении. Результаты данного
исследования целесообразно использовать при проектировании объектов теплоэнергетикиFrom the profiles of the curves of differential scanning calorimetry, the maximum intensity of the heat flux, as well as the endothermic and exothermic effects of the combustion of wastewater residues (SWS) were determined. Sludge wastewater residues have a high ash content (more than 50 %), which reduces the value of the lower calorific value in the working state. The high content of volatile substances (more than 80 %) ensures early ignition at a temperature of 268 °C. Having a low ignition temperature, they can be a promising additional fuel to coal after enrichment in order to significantly reduce the ash content and increase the calorific value. The low value of the combustion index equal to 0.4×10–6 is due to the low value of the maximum reaction rate equal to 13 %/min and the high burnout temperature equal to 633 °C. The conducted studies have shown that the combustion of WWS does not lead to a deterioration in the operating conditions of the furnace screens in boiler furnaces due to the high content of minerals in the ash with a high melting point (iron and calcium phosphates). The high content of phosphorus in wastewater residues contributes to the immobilization of mobile iron into phosphates. Such a composition of WWS will help to reduce the mobility of heavy metals in slag and ash residues of co-combustion with coal during subsequent long-term storage. The results of this study should be used in the design of thermal power facilitie
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
Hydrocarbon films obtained by electron beam for micropatterning in liquid crystal diffraction grating
We demonstrate very simple method of obtaining the nano-scale hydrocarbon (CH) covering for orientation of liquid crystal. We used a snuff effect of hydrocarbon film on the surface of the substrate in a residual atmosphere of electron scanning microscope under electron beam for micropatterning in liquid crystal cell. By means of such a method the nano dimension CH films were produced as stripes with micron size needed for liquid crystal diffraction grating. Qualitative polarization analysis shows that liquid crystal orientation over CH film depends on its thickness. It is established that in LC cell with homeotropic reference surface the liquid crystal orientation over closed arranged narrow CH stripes is uniform. The performed liquid crystal grating demonstrates a satisfactory resolution and effective electric field control
The Mathematical Description for the Electropolymerization of Electrochemically Modified Monomers in Galvanostatic Mode
Математически описана система с электрополимеризацией электрохимически
модифицированных органических мономеров в гальваностатическом режиме.
Соответствующая математическая модель была проанализирована с помощью
линейной теории устойчивости и бифуркационного анализа. Показано, что причиной
автоколебательного поведения в таких системах могут быть влияния на ДЭС
электрохимических реакций на первой и второй стадиях. Условия устойчивости
стационарного состояния, а также монотонной неустойчивости также были найденыThe system with galvanostatic electropolymerization of electrosynthetized monomers was described
mathematically. The correspondent mathematical model was analyzed by using of linear stability
theory and bifurcation analysis. It was shown that the oscillatory behavior may be caused by the
influences on DEL of electrochemical reactions on the first and the second stage. The steady-state
stability conditions and the conditions for the monotonic instability were also foun
Development of the Method of Evaluation of the Level of Environmental Safety of Housing Accommodation and Its Approbation
The method of estimating the level of ecological safety of a housing accommodation by environmental factors: physical, chemical, microclimatic and aesthetic is presented. Groups of danger factors in the structure of such a category of life quality as “Environmental safety of a dwelling house” are formed.The analysis of modern scientific studies showed that the vast majority of researchers use the survey method when assessing the quality of dwellings. This approach is justified in terms of the ease of processing the results. However, when using this approach, it is difficult to avoid subjectivity in assessment.Qualimetric tables have been compiled for the scoring assessment of the selected environmental hazards factors. Based on the values of the hazard factors scoring assessment and their weight determination, a formula is proposed for determining the numerical value of the integral indicator of the environmental safety of the dwelling.The application of the developed method allows:– assessing the existing environmental safety level of residential premises to manage its quality, in terms of both new construction and reconstruction;– justifying the choice of new architectural projects regarding environmental safety in the room;– estimating the cost of a premise when it is purchased on the primary or secondary market in the conditions of equivalence of all other parameters such as location, the state of the infrastructure of the district, etc