Constraints on axionlike particles with H.E.S.S. from the irregularity of the PKS 2155-304 energy spectrum

Axionlike particles (ALPs) are hypothetical light (sub-eV) bosons predicted in some extensions of the Standard Model of particle physics. In astrophysical environments comprising high-energy gamma rays and turbulent magnetic fields, the existence of ALPs can modify the energy spectrum of the gamma rays for a sufficiently large coupling between ALPs and photons. This modification would take the form of an irregular behavior of the energy spectrum in a limited energy range. Data from the H.E.S.S. observations of the distant BL Lac object PKS 2155-304 (z=0.116) are used to derive upper limits at the 95% C.L. on the strength of the ALP coupling to photons, ggammaa<2.1×10-11GeV-1 for an ALP mass between 15 and 60 neV. The results depend on assumptions on the magnetic field around the source, which are chosen conservatively. The derived constraints apply to both light pseudoscalar and scalar bosons that couple to the electromagnetic fieldFil: Medina, Maria Clementina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto Argentino de Radioastronomia (i); ArgentinaFil: H.E.S. S. collaboration

Methods of restoring the integrity the lower jaw in children with post-resection defects' [Metody vosstanovleniia tselostnosti nizhneĭ cheliusti u deteĭ s postrezektsionnymi defektami]

The review deals with modern concepts on surgical treatment of post-resection defects of the mandible in children. The analysis of domestic and foreign literature. Describes the various classification of tumor lesions in children and post-resection defects of the mandible. Highlighted the advantages and disadvantages, and the prospects for recovery of integrity of the mandible in children.Обзор посвящен современным представлениям о хирургическом лечении и методах восстановления пострезекционных дефектов нижней челюсти. Проведен анализ отечественной и зарубежной литературы. Описаны различные классификации опухолевых поражений у детей и пострезекционных дефектов нижней челюсти. Подчеркнуты преимущества и недостатки, а также перспективы восстановления целостности нижней челюсти у детей

Research possibility of application of non-destructive testing method based on the Barkhausen effect for the control of heat exchange equipment, exposed to im-pulse pressure

The article deals with the issues of ensuring the reliability of operation and methods for evaluation of connections (tube attachment points in tube sheets) of heat exchangers used in various industries. It is estimated the applicability of the control method based on the Barkhausen effect to check the place of tube fastening in tube sheets. Installations are considered as heat exchangers in which the connection is derive pipe with tube sheets is obtained by using impulsed pressure sources

Methods of restoring the integrity the lower jaw in children with post-resection defects' [Metody vosstanovleniia tselostnosti nizhneĭ cheliusti u deteĭ s postrezektsionnymi defektami]

The review deals with modern concepts on surgical treatment of post-resection defects of the mandible in children. The analysis of domestic and foreign literature. Describes the various classification of tumor lesions in children and post-resection defects of the mandible. Highlighted the advantages and disadvantages, and the prospects for recovery of integrity of the mandible in children.Обзор посвящен современным представлениям о хирургическом лечении и методах восстановления пострезекционных дефектов нижней челюсти. Проведен анализ отечественной и зарубежной литературы. Описаны различные классификации опухолевых поражений у детей и пострезекционных дефектов нижней челюсти. Подчеркнуты преимущества и недостатки, а также перспективы восстановления целостности нижней челюсти у детей

Фиброзная дисплазия челюстно-лицевой области: клинико-рентгенологический анализ 15-летнего опыта

The study objective is to determine the clinical and radiological characteristics of fibrous dysplasia of the maxillofacial area in children.Materials and methods. A retrospective analysis of the data of the Department of Maxillofacial Surgery of the Russian Children’s Clinic for 15 years was performed. Clinical manifestations of fibrous dysplasia were compared with the X-ray characteristics in 86 patients.Results and conclusion. In the study group, boys (in 1.2 times) slightly prevailed. The median age of debut of the disease was 8.4 years, and the time before treatment was 2.2 years. The main complaint was the appearance of a painless slowly progressing deformation. Most often, the maxilla and frontal bone were affected. X-ray fibrous dysplasia was manifested by the presence of a focus with a reduced density, relative to the adjacent bone, the type of “ground glass” with the possible presence of cysts.Цель исследования – определить клинико-рентгенологические особенности фиброзной дисплазии челюстно-лицевой области у детей.Материалы и методы. Проведен ретроспективный анализ данных отделения челюстно-лицевой хирургии Российской детской клинической больницы за 15 лет. Клинические проявления фиброзной дисплазии были сопоставлены с рентгенологической картиной у 86 пациентов.Результаты и заключение. Среди пациентов доля мальчиков была в 1,2 раза больше. Средний возраст дебюта заболевания составил 8,4 года, а среднее время от дебюта до обращения к врачу – 2,2 года. Основной жалобой было появление безболезненной медленно прогрессирующей деформации. Чаще всего зоной поражения была верхняя челюсть и лобная кость. Рентгенологически фиброзная дисплазия проявлялась наличием очага пониженной плотности (относительно плотности прилегающей кости) по типу «матового стекла» с возможным наличием кист

Theoretical shear strength and the onset of plasticity in nanodeformation of cubic boron nitride

The nanoindentation in the continuous stiffness measurement mode was used to investigate the onset of plasticity at the nanodeformation of cubic boron nitride (cBN). This technique allows us to reveal an elastic-plastic transition in the contact and to measure the yield strength of cBN at the nanoscale. An abrupt elastoplastic transition (a pop-in) was observed in the (111) cBN single crystal as a result of a homogeneous or heterogeneous nucleation of dislocations in the previously dislocations-free region under the contact. The analysis of the data obtained at the homogeneous nucleation of dislocations in the contact region made it possible to experimentally estimate the theoretical shear strength of cBN and its ideal (elastic) hardness. In a sample of the fine-grained cBN with a nanotwinned substructure a smooth elastoplastic transition was observed in consequence of the propagation and multiplication of already existing dislocations in the contact region