Calculation of The Lifetimes of Thin Stripper Targets Under Bombardment of Intense Pulsed Ions

The problems of stripper target behavior in the nonstationary intense particle beams are considered. The historical sketch of studying of radiation damage failure of carbon targets under ion bombardment is presented. The simple model of evaporation of a target by an intensive pulsing beam is supposed. Stripper foils lifetimes in the nonstationary intense particle can be described by two failure mechanisms: radiation damage accumulation and evaporation of target. At the maximal temperatures less than 2500K the radiation damage are dominated; at temperatures above 2500K the mechanism of evaporation of a foil prevails. The proposed approach has been applied to the discription of behaviour of stripper foils in the BNL linac and SNS conditions.Comment: 12 pages, 5 figure

Analysis of Structure Destroyed Metal after Diffusion Heat Treatment

It was accomplished research of the structure steel which carbonitriding and subsequent heat treatment was exposed for its cause's destruction to discover. For measure quality field of metal were used methods optical, appearing electronic microscopy and X-ray diffraction. Therefore one of the principal problems were research phase composition, grain and dislocation structure of a metal the gear teeth. Mechanism of rising hear cracks in the gear teeth on different stages her making and their trajectories of evolution were determined

Effect of tantalum on the tensile properties of 12%Cr martensitic steels for steam blades

Co-modified 12%Cr martensitic steels are perspective materials for steam blades for fossil power plants which are able to work at ultra-supercritical parameters of steam (T=620-650°C, P=2530 MPa

Anomalous behavior of the acoustic phonon velocity and elastic constants of relaxor ferroelectric PbMg1/3Ta2/3O3

The behavior of longitudinal acoustic (LA) and transverse acoustic (TA) phonons in a cubic relaxor PbMg1/3Ta2/3O3 (PMT) ferroelectric has been investigated by Brillouin light scattering. Analysis of the temperature dependences of phonon velocity in the temperature range from 50 to 870 K has revealed anomalies in the vicinity of the Burns temperature (TB≈570 K) for LA phonons and a wide frequency-dependent minimum of the velocities of LA and TA phonons in the same temperature region as the dielectric response anomaly. Using experimental data, temperature dependences of the C11 and C44 elastic constants have been calculated. The elastic constants have been found to be frequency-independent in the gigahertz range. The results obtained are discussed in the framework of modern ideas on the crystalline lattice dynamics of relaxor ferroelectrics

Predictive Modelling of Surface Roughness in Layered Manufacturing Using H15N5D4B and KH28M6

Layered manufacturing (LM) technology has the capability to fabricate 3D physical models efficiently, overcoming the limitations of geometric complexities. However, the surface quality of LM-processed parts often falls short compared to parts made through traditional numerically controlled manufacturing technology. This issue of surface roughness has become a significant concern, despite the numerous potential advantages offered by LM. To address this, an elaborate methodology is proposed to predict the surface roughness of LM-processed parts. The proposed methodology takes into account both theoretical and real-world characteristics of surface roughness distributions to accurately reflect the actual roughness distributions in the predictions. This methodology was tested and used to evaluate properties of the H15N5D4B and KH28M6 materials. To achieve this, a design of the testing sample was developed, and a roughness distribution expression was introduced, utilizing measured roughness data from the aforementioned sample. This expression allows engineers to obtain surface roughness values for all surface angles, i.e., desired 3D models. The methodology also includes a prediction application, which demonstrates the validity and effectiveness of the proposed approach through several application examples

Reactive Desorption of CO Hydrogenation Products under Cold Pre-stellar Core Conditions

The astronomical gas-phase detection of simple species and small organic molecules in cold pre-stellar cores, with abundances as high as $\sim$$10^{-8}-10^{-9}$ n$_\text{H}$, contradicts the generally accepted idea that at $10$ K, such species should be fully frozen out on grain surfaces. A physical or chemical mechanism that results in a net transfer from solid-state species into the gas phase offers a possible explanation. Reactive desorption, i.e., desorption following the exothermic formation of a species, is one of the options that has been proposed. In astronomical models, the fraction of molecules desorbed through this process is handled as a free parameter, as experimental studies quantifying the impact of exothermicity on desorption efficiencies are largely lacking. In this work, we present a detailed laboratory study with the goal of deriving an upper limit for the reactive desorption efficiency of species involved in the CO-H$_2$CO-CH$_3$OH solid-state hydrogenation reaction chain. The limit for the overall reactive desorption fraction is derived by precisely investigating the solid-state elemental carbon budget, using reflection absorption infrared spectroscopy and the calibrated solid-state band-strength values for CO, H$_2$CO and CH$_3$OH. We find that for temperatures in the range of $10$ to $14$ K, an upper limit of $0.24\pm 0.02$ for the overall elemental carbon loss upon CO conversion into CH$_3$OH. This corresponds with an effective reaction desorption fraction of $\leq$$0.07$ per hydrogenation step, or $\leq$$0.02$ per H-atom induced reaction, assuming that H-atom addition and abstraction reactions equally contribute to the overall reactive desorption fraction along the hydrogenation sequence. The astronomical relevance of this finding is discussed.Comment: 9 pages, 7 figure

Universality of pseudogap and emergent order in lightly doped Mott insulators

It is widely believed that high-temperature superconductivity in the cuprates emerges from doped Mott insulators. The physics of the parent state seems deceivingly simple: The hopping of the electrons from site to site is prohibited because their on-site Coulomb repulsion U is larger than the kinetic energy gain t. When doping these materials by inserting a small percentage of extra carriers, the electrons become mobile but the strong correlations from the Mott state are thought to survive; inhomogeneous electronic order, a mysterious pseudogap and, eventually, superconductivity appear. How the insertion of dopant atoms drives this evolution is not known, nor whether these phenomena are mere distractions specific to hole-doped cuprates or represent the genuine physics of doped Mott insulators. Here, we visualize the evolution of the electronic states of (Sr1-xLax)2IrO4, which is an effective spin-1/2 Mott insulator like the cuprates, but is chemically radically different. Using spectroscopic-imaging STM, we find that for doping concentration of x=5%, an inhomogeneous, phase separated state emerges, with the nucleation of pseudogap puddles around clusters of dopant atoms. Within these puddles, we observe the same glassy electronic order that is so iconic for the underdoped cuprates. Further, we illuminate the genesis of this state using the unique possibility to localize dopant atoms on topographs in these samples. At low doping, we find evidence for much deeper trapping of carriers compared to the cuprates. This leads to fully gapped spectra with the chemical potential at mid-gap, which abruptly collapse at a threshold of around 4%. Our results clarify the melting of the Mott state, and establish phase separation and electronic order as generic features of doped Mott insulators.Comment: This version contains the supplementary information and small updates on figures and tex

Prevention of postoperative ventral hernia by choosing the method of suturing the laparotomy wound, taking into account its tension

The aim of the study was to improve the results of treatment of patients undergoing median laparotomy by reducing the number of postoperative ventral hernias and eventrations. Materials and methods In the first stage, 34 patients operated on for diseases of the abdominal cavity were examined to determine the level of normal tension of the edges of the white line of the abdomen. At the second stage, a group of 42 patients operated on via the median laparotomic access was identified, in which the tension indicator was increased, dividing them into two groups. In the main group, the white line was sutured with a continuous chess stitch and strengthening, superimposed on the areas with the greatest tension. Tension was measured using the developed device. In the control group, the median aponeurosis was sutured with a continuous chess stitch. Results There was one event (5%) in the control group, there was no eventration in the main eventration. After one year, two (9%) patients with defects in aponeurosis were identified in the main group. In the control aponeurosis defects were two (10%), and postoperative hernias two (10%). Conclusions Thus, the use of a continuous chess stitch in combination with strengthening, taking into account the tension, the edges of the white line of the abdomen, is a way to prevent eventration and postoperative ventral hernias.Целью исследования явилось улучшение результатов лечения больных подвергшихся срединной лапаротомии путем уменьшения количества послеоперационных вентральных грыж и эвентраций. Материалы и методы на первом этапе обследовано 34 больных, оперированных по поводу заболеваний брюшной полости, на предмет выявления уровня нормального натяжения краёв белой линии живота. На втором этапе выявили группу из 42 больных, оперированных через срединный лапаротомный доступ, у которых показатель натяжения был повышен, разделив их на две группы. В основной группе белая линия ушивалась непрерывным шахматным швом и укрепляющими, наложенными на участки с наибольшим натяжением. Натяжение измеряли с помощью разработанного устройства. В контрольной группе срединный апоневроз ушивался непрерывным шахматным швом. Результаты В контрольной группе была одна (5%) эвентрация, в основной эвентраций не было. Через один год в основной группе выявлено двое (9%) больных с дефектами апоневроза. В контрольной группе дефектов апоневроза было два (10%), послеоперационных грыж две (10%). Выводы. Таким образом, использование непрерывного шахматного шва в сочетании с укрепляющими с учетом натяжения краёв белой линии живота, является способом профилактики эвентраций и послеоперационных вентральных грыж

Development of Intoxication syndrome in patients w ith acute pancreatitis on the background of enteral correction

An important part of the treatment of patients with acute pancreatitis is the fight against the syndrome of enteral insufficiency. In our study we examined the effect of the appointment of prebiotics and probiotics on the basic parameters of enteral insufficiency syndrome and endogenous intoxication, which developed as a result of acute pancreatitis. A clear positive impact of the proposed treatment was determined.Одной из важных составляющих лечения пациентов с острым панкреатитом является борьба с синдромом энтеральной недостаточности. В своём исследовании мы рассматривали влияние назначения пребиотиков и пробиотиков на основные параметры синдромов энтеральной недостаточности и эндогенной интоксикации, развившихся вследствие острого панкреатита. Как результат отмечено явное позитивное влияние предложенной лечебной схемы