244 research outputs found

    Numerical simulation of synthesis gas incineration

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    The authors have analysed the expediency of the suggested low-grade fuels application method. Thermal processing of solid raw materials in the gaseous fuel, called synthesis gas, is investigated. The technical challenges concerning the applicability of the existing gas equipment developed and extensively tested exclusively for natural gas were considered. For this purpose computer simulation of three-dimensional syngas-incinerating flame dynamics was performed by means of the ANSYS Multiphysics engineering software. The subjects of studying were: a three-dimensional aerodynamic flame structure, heat-release and temperature fields, a set of combustion properties: a flare range and the concentration distribution of burnout reagents. The obtained results were presented in the form of a time-averaged pathlines with color indexing. The obtained results can be used for qualitative and quantitative evaluation of complex multicomponent gas incineration singularities

    Dependence of the diffusion wear of the hard alloy surface on its fractal dimension

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    The paper presents the research results in the synergies between the wear resistance of carbide cutting tools of P-group applicability and fractal dimension of the wear surface occurring on the rake face of the tool when processing the material, which causes intensive diffusion wear. It was found that the resistance of carbide cutting tools increases as the fractal dimension of their wear surface reduces

    Features of empathy among students of the direction "Ecology and nature management" with different mathematical abilities and strategies for conveying meaning

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    Today, the entire education of the Russian Federation is being reformed, high requirements for the quality of education have been set. The restructuring and integration of the world educational process expects high efficiency of all educational activities, therefore, the problem of the study of mathematical abilities and the ability to convey meaning of students is particularly relevant today. Equally important is the problem of educating socially approved personality traits in the younger generation, including empathy. The study allowed us to establish that students with an average level of development of mathematical abilities have significantly less formed empathy, and vice versa, with the development of communicative properties, there is an increase in empathy abilities. It has been established that empathy is best formed in students of the direction "Ecology and nature management" with an active, emotionally dominant and cognitively dominant strategy for conveying meaning

    Closed-system behaviour of the Re-Os isotope system recorded in primary and secondary platinum-group mineral assemblages : evidence from a mantle chromitite at Harold's Grave (Shetland ophiolite complex, Scotland)

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    This study evaluates in detail the mineral chemistry, wholerock and mineral separate Os-isotope compositions of distinct platinumgroup mineral (PGM) assemblages in an isolated chromitite pod at Harold's Grave which occurs in mantle tectonite in the Shetland Ophiolite Complex (SOC), Scotland. This was the first ophiolite sequence worldwide that was shown to contain ppm levels of all six platinum-group elements (PGE) in podiform chromitite, including the contrasting type localities found here and at Cliff. At Harold's Grave the primary PGM assemblage is composed mainly of laurite and/or Os-rich iridium and formed early together with chromite, whereas the secondary PGM assemblage dominated by laurite, Osrich laurite, irarsite, native osmium and Ru-bearing pentlandite is likely to reflect processes including in-situ serpentinization, alteration during emplacement and regional greenschist metamorphism. The osmium isotope data define a restricted range of 'unradiogenic' 187Os/188Os values for coexisting laurite and Os-rich alloy pairs from 'primary' PGM assemblage (0.12473-0.12488) and similar 'unradiogenic' 187Os/188Os values for both 'primary' and 'secondary' PGM assemblages (0.1242±0.0008 and 0.1245±0.0006, respectively), which closely match the bulk 187Os/188Os value of their host chromitite (0.1240±0.0006). The unprecedented isotopic similarity between primary or secondary PGM assemblages and chromitite we report suggests that the osmium isotope budget of chromitite is largely controlled by the contained laurite and Os-rich alloy. This demonstrates that closed system behaviour of the Re- Os isotope system is possible, even during complex postmagmatic hydrothermal and/or metamorphic events. The preserved mantle Os-isotope signatures provide further support for an Enstatite Chondrite Reservoir (ECR) model for the convective upper mantle and are consistent with origin of the complex as a Caledonian ophiolite formed in a suprasubduction zone setting shortly before obduction

    Historical Patterns of Diagnosis, Treatments, and Outcome of Epilepsy Associated With Tuberous Sclerosis Complex: Results From TOSCA Registry

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    TOSCA; Epilepsia; RegistroTOSCA; Epilèpsia; RegistreTOSCA; Epilepsy; RegistryBackground: Epilepsy is the most common neurological manifestation in individuals with tuberous sclerosis complex (TSC). However, real-world evidence on diagnosis and treatment patterns is limited. Here, we present data from TuberOus Sclerosis registry to increase disease Awareness (TOSCA) on changes in patterns of epilepsy diagnosis, treatments, and outcomes over time, and detailed epilepsy characteristics from the epilepsy substudy. Methods: TuberOus Sclerosis registry to increase disease Awareness (TOSCA) was a multicentre, international disease registry, consisting of a main study that collected data on overall diagnostic characteristics and associated clinical features, and six substudies focusing on specific TSC manifestations. The epilepsy substudy investigated detailed epilepsy characteristics and their correlation to genotype and intelligence quotient (IQ). Results: Epilepsy was reported in 85% of participants, more commonly in younger individuals (67.8% in 1970s to 91.8% in last decade), while rate of treatments was similar across ages (>93% for both infantile spasms and focal seizures, except prior to 1960). Vigabatrin (VGB) was the most commonly used antiepileptic drugs (AEDs). Individuals with infantile spasms showed a higher treatment response over time with lower usage of steroids. Individuals with focal seizures reported similar rates of drug resistance (32.5–43.3%). Use of vagus nerve stimulation (VNS), ketogenic diet, and surgery remained low. Discussion: The epilepsy substudy included 162 individuals from nine countries. At epilepsy onset, most individuals with infantile spasms (73.2%) and focal seizures (74.5%) received monotherapies. Vigabatrin was first-line treatment in 45% of individuals with infantile spasms. Changes in initial AEDs were commonly reported due to inadequate efficacy. TSC1 mutations were associated with less severe epilepsy phenotypes and more individuals with normal IQ. In individuals with TSC diagnosis before seizure onset, electroencephalogram (EEG) was performed prior to seizures in only 12.5 and 25% of subsequent infantile spasms and focal seizures, respectively. Conclusions: Our study confirms the high prevalence of epilepsy in TSC individuals and less severe phenotypes with TSC1 mutations. Vigabatrin improved the outcome of infantile spasms and should be used as first-line treatment. There is, however, still a need for improving therapies in focal seizures. Electroencephalogram follow-up prior to seizure-onset should be promoted for all infants with TSC in order to facilitate preventive or early treatment.The study was funded by Novartis Pharma AG. Novartis has contributed to study design, data analysis and the decision to publish. Novartis authors reviewed the draft for submission

    Four-year update of the EXIST-2 study

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    Objectives We examined the long-term effects of everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. Methods Following favorable results from the double- blind core phase of EXIST-2 (NCT00790400), patients were allowed to receive open-label everolimus (extension phase). Patients initially randomly assigned to everolimus continued on the same dose; those who were receiving placebo crossed over to everolimus 10 mg/day. Dose modifications were based on tolerability. The primary end point was angiomyolipoma response rate, defined as a ≥50% reduction from baseline in the sum volume of target renal angiomyolipomas in the absence of new target angiomyolipomas, kidney volume increase of >20% from nadir, and angiomyolipoma-related bleeding grade ≥2. The key secondary end point was safety. Results Of the 112 patients who received ≥1 dose of everolimus, 58% (95% CI, 48.3% to 67.3%) achieved angiomyolipoma response. Almost all patients (97%) experienced reduction in renal lesion volumes at some point during the study period. Median duration of everolimus exposure was 46.9 months. Sixteen (14.3%) patients experienced angiomyolipoma progression at some point in the study. No angiomyolipoma-related bleeding or nephrectomies were reported. One patient on everolimus underwent embolization for worsening right flank pain. Subependymal giant cell astrocytoma lesion response was achieved in 48% of patients and skin lesion response in 68% of patients. The most common adverse events suspected to be treatment-related were stomatitis (42%), hypercholesterolemia (30.4%), acne (25.9%), aphthous stomatitis and nasopharyngitis (each 21.4%). Ten (8.9%) patients withdrew because of an adverse event. Renal function remained stable, and the frequency of emergent adverse events generally decreased over time. Conclusions Everolimus treatment remained safe and effective over approximately 4 years. The overall risk/benefit assessment supports the use of everolimus as a viable treatment option for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. Trial registration ClinicalTrials.gov NCT0079040
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