41 research outputs found

    Pragmatic approach to the little hierarchy problem: the case for Dark Matter and neutrino physics

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    We show that the addition of real scalars (gauge singlets) to the Standard Model can both ameliorate the little hierarchy problem and provide realistic Dark Matter candidates. To this end, the coupling of the new scalars to the standard Higgs boson must be relatively strong and their mass should be in the 1-3 TeV range, while the lowest cutoff of the (unspecified) UV completion must be >~ 5 TeV, depending on the Higgs boson mass and the number of singlets present. The existence of the singlets also leads to realistic and surprisingly reach neutrino physics. The resulting light neutrino mass spectrum and mixing angles are consistent with the constraints from the neutrino oscillations.Comment: discussion of multi singlet case adde

    Применение самораспространяющегося высокотемпературного синтеза для получения защитно-упрочняющих алюмосиликатных покрытий

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    This article shows the possibility of using the method of self-propagating high-temperature synthesis to obtain protective and hardening coatings for the lining of various thermal installations. The development of compositions of ceramic masses for the production of SHS coatings was carried out on the basis of aluminum powder, clay raw materials, exhausting and fluxing components as well as mineralizing additives. The prepared suspension including pre-prepared and thoroughly mixed raw materials was applied with a brush or a spray gun onto the previously cleaned and moistened surface of an aluminosilicate refractory. The firing of the coating was carried out in accordance with the mode of removing the thermal unit at the operating temperature. The temperature of the initiation of the SHS process, previously established using differential thermal analysis, was in the range of 570–720 °C and depended on the chemical composition of the charge. It has been established that the presence of crystalline phases of silica, corundum, hematite and a number of solid solutions (mainly calcium and sodium aluminosilicates) in the coating structure provides the necessary combination of the thermomechanical and thermophysical characteristics of the coatings. On the basis of the conducted research, the expediency of applying the technology of self-propagating high-temperature synthesis for the production of protective and hardening coatings on the lining of thermal units is demonstrated, which is confirmed by industrial tests in the conditions of the Minsk Ceramic Factory OJSC «Keramin».Показана возможность использования метода самораспространяющегося высокотемпературного синтеза для получения защитно-упрочняющих покрытий по футеровке различных тепловых установок. Разработка составов керамических композиций для получения СВС-покрытий осуществлялась на основе алюминиевой пудры, глинистого сырья, отощающих и флюсующих компонентов, а также минерализующих добавок. Приготовленную суспензию, включающую предварительно подготовленные и тщательно перемешанные сырьевые компоненты, с помощью кисти или пульверизатора наносили на предварительно очищенную и увлажненную поверхность алюмосиликатного огнеупора. Обжиг покрытия осуществляли в соответствии с режимом выведения теплового агрегата на рабочую температуру. Температура инициирования процесса СВС, предварительно установленная с помощью дифференциально-термического анализа, находилась в интервале 570–720 °С и зависела от химического состав шихты. Установлено, что наличие в структуре покрытий кристаллических фаз кремнезема, корунда, гематита, а также ряда твердых растворов (преимущественно алюмосиликаты кальция и натрия) обеспечивает необходимое сочетание термомеханических и теплофизических характеристик покрытий. На основании проведенных исследований показана целесообразность применения технологии СВС для получения защитно-упрочняющих покрытий по футеровке тепловых агрегатов, что подтверждено промышленными испытаниями в условиях Минского керамического завода ОАО «Керамин»

    Multilayered vacuum-arc nanocomposite TiN/ZrN coatings before and after annealing: Structure, properties, first-principles calculations

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    Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 °C. All deposited samples were highly polycrystalline with quite large 20–25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 °C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance

    Multilayered vacuum-arc nanocomposite TiN/ZrN coatings before and after annealing: Structure, properties, first-principles calculations

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    Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 °C. All deposited samples were highly polycrystalline with quite large 20–25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 °C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance

    The European Registry for Patients with Mechanical Circulatory Support (EUROMACS)

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    OBJECTIVES: A second paediatric report has been generated from the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). The purpose of EUROMACS, which is operated by the European Association for Cardio-Thoracic Surgery, is to gather data related to durable mechanical circulatory support for scientific purposes and to publish reports with respect to the course of mechanical circulatory support therapy. Since the first report issued, efforts to increase compliance and participation have been extended. Additionally, the data provided the opportunity to analyse patients of younger age and lower weight. METHODS: Participating hospitals contributed pre-, peri- and long-term postoperative data on mechanical circulatory support implants to the registry. Data for all implants in paediatric patients (≤19 years of age) performed from 1 January 2000 to 1 July 2019 were analysed. This report includes updates of patient characteristics, implant frequency, outcome (including mortality rates, transplants and recovery rates) as well as adverse events including neurological dysfunction, device malfunction, major infection and bleeding. RESULTS: Twenty-nine hospitals contributed 398 registered implants in 353 patients (150 female, 203 male) to the registry. The most frequent aetiology of heart failure was any form of cardiomyopathy (61%), followed by congenital heart disease and myocarditis (16.4% and 16.1%, respectively). Competing outcomes analysis revealed that a total of 80% survived to transplant or recovery or are ongoing; at the 2-year follow-up examination, 20% died while on support. At 12 months, 46.7% received transplants, 8.7% were weaned from their device and 18.5% died. The 3-month adverse events rate was 1.69 per patient-year for device malfunction including pump exchange, 0.48 for major bleeding, 0.64 for major infection and 0.78 for neurological events. CONCLUSIONS: The overall survival rate was 81.5% at 12 months following ventricular assist device implant. The comparison of survival rates of the early and later eras shows no significant difference. A focus on specific subgroups showed that survival was less in patients of younger age (<1 year of age) (P = 0.01) and lower weight (<20 kg) (P = 0.015). Transplant rates at 6 months contin

    Logistics control of the resources flow in energy-saving projects: Case study for metallurgical industry

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    The multilevel model for the formation and assessment of resource flows of a metallurgical enterprise is presented, which, at the logistics positions, reconcile the enterprise flow processes at all management levels, providing procedures for regulating the parameters of material and financial flows due to parametric and structural coordination in the short period of time and system coordination and adaptation of goals in the long term period. Drawing on the theory of logistics, it is possible to define the resource flow in project management as an aggregate of the enterprise’s own and attracted resources, considering in the process of interconnected and interdependent changes and movements carried out to achieve the objectives of the project. Optimization models of rational options selection for attracting additional resources, which allow implementing energy-saving projects under conditions of suspending finances at definite time periods due to a change in the project implementation schedule are described

    CTIP2 Expression in Human Head and Neck Squamous Cell Carcinoma Is Linked to Poorly Differentiated Tumor Status

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    We have demonstrated earlier that CTIP2 is highly expressed in mouse skin during embryogenesis and in adulthood. CTIP2 mutant mice die at birth with epidermal differentiation defects and a compromised epidermal permeability barrier suggesting its role in skin development and/or homeostasis. CTIP2 has also been suggested to function as tumor suppressor in cells, and several reports have described a link between chromosomal rearrangements of CTIP2 and human T cell acute lymphoblast leukemia (T-ALL). The aim of the present study was to look into the pattern of CTIP2 expression in Head and Neck Squamous Cell Carcinoma (HNSCC).In the present study, we analyzed CTIP2 expression in human HNSCC cell lines by western blotting, in paraffin embedded archival specimens by immunohistochemistry (IHC), and in cDNA samples of human HNSCC by qRT-PCR. Elevated levels of CTIP2 protein was detected in several HNSCC cell lines. CTIP2 staining was mainly detected in the basal layer of the head and neck normal epithelium. CTIP2 expression was found to be significantly elevated in HNSCC (p<0.01), and increase in CTIP2 expression was associated with poorly differentiated tumor status. Nuclear co-localization of CTIP2 protein and cancer stem cell (CSC) marker BMI1 was observed in most, if not all of the cells expressing BMI1 in moderately and poorly differentiated tumors.We report for the first time expression of transcriptional regulator CTIP2 in normal human head and neck epithelia. A statistically significant increase in the expression of CTIP2 was detected in the poorly differentiated samples of the human head and neck tumors. Actual CTIP2, rather than the long form of CTIP2 (CTIP2(L)) was found to be more relevant to the differentiation state of the tumors. Results demonstrated existence of distinct subsets of cancer cells, which express CTIP2 and underscores the use of CTIP2 and BMI1 co-labeling to distinguish tumor initiating cells or cancer stem cells (CSCs) from surrounding cancer cells

    An osteocalcin-deficient mouse strain without endocrine abnormalities

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    Osteocalcin (OCN), the most abundant noncollagenous protein in the bone matrix, is reported to be a bone-derived endocrine hormone with wide-ranging effects on many aspects of physiology, including glucose metabolism and male fertility. Many of these observations were made using an OCN-deficient mouse allele (Osc– ) in which the 2 OCN-encoding genes in mice, Bglap and Bglap2, were deleted in ES cells by homologous recombination. Here we describe mice with a new Bglap and Bglap2 double-knockout (dko) allele (Bglap/2p.Pro25fs17Ter) that was generated by CRISPR/Cas9-mediated gene editing. Mice homozygous for this new allele do not express full-length Bglap or Bglap2 mRNA and have no immunodetectable OCN in their serum. FTIR imaging of cortical bone in these homozygous knockout animals finds alterations in the collagen maturity and carbonate to phosphate ratio in the cortical bone, compared with wild-type littermates. However, μCT and 3-point bending tests do not find differences from wild-type littermates with respect to bone mass and strength. In contrast to the previously reported OCN-deficient mice with the Osc− allele, serum glucose levels and male fertility in the OCN-deficient mice with the Bglap/ 2pPro25fs17Ter allele did not have significant differences from wild-type littermates. We cannot explain the absence of endocrine effects in mice with this new knockout allele. Possible explanations include the effects of each mutated allele on the transcription of neighboring genes, or differences in genetic background and environment. So that our findings can be confirmed and extended by other interested investigators, we are donating this new Bglap and Bglap2 double-knockout strain to the Jackson Laboratories for academic distribution

    Potential range of impact of an ecological trap network: the case of timber stacks and the Rosalia longicorn

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    Although the negative impact of timber stacks on populations of saproxylic beetles is a well-known phenomenon, there is relatively little data concerning the scale of this impact and its spatial aspect. Beech timber stored in the vicinity of the forest can act as an ecological trap for the Rosalia longicorn (Rosalia alpina), so in this study we have attempted to determine the spatial range of the impact of a network of timber stacks. Timber stacks in the species’ range in the study area were listed and monitored during the adult emergence period in 2014–2016. Based on published data relating to the species’ dispersal capabilities, buffers of four radii (500, 1000, 1600, 3000 m) were delineated around the stacks and the calculated ranges of potential impact. The results show that the percentage of currently known localities of the Rosalia longicorn impacted by stacks varies from 19.7 to 81.6%, depending on the assumed impact radius. The percentage of forest influenced by timber stacks was 77% for the largest-radius buffer. The overall impact of the ecological trap network is accelerated by fragmentation of the impact-free area. It was also found that forests situated close to the timber stacks where the Rosalia longicorn was recorded were older and more homogeneous in age and species composition than those around stacks where the species was absent. Such results suggest that timber stacks act as an ecological trap in the source area of the local population
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