The paper presents the results of calculating the stresses and strains of manometric tubular springs under loading by internal pressure and external force. For research, the finite element method ...implemented in the ANSYS program was used. The problems of constructing a grid model of the tubular element were solved, the displacements of the free end and stresses from internal pressure were determined, and the maximum permissible pressure value was found.
Refractory foam concrete has been developed in terms of its composition for long-term use at high temperatures in the nuclear power industry. Foam concrete based on Portland cement has an average ...density class of D700 and a maximum permissible application temperature class of I5 (500°C). Refractory foam concrete has improved deformation characteristics in terms of its axial tension and tensile strength in bending. This study investigated the strength variations of refractory foam concrete samples as a function of the heating temperature up to 400°C and prolonged exposure (up to 2000 h) at 200 and 400°C. A thermodynamic calculation was performed with the possible formation of low-base hydrosilicates (gyrolite and afwillite) up to 400°C, which was confirmed by the results of studies on the phase composition of the refractory foam concrete samples.
The goal of the paper is to describe the large time behaviour of a symmetric diffusion in a high-contrast periodic environment and to characterize the limit process under the diffusive scaling. We ...consider separately the
and
settings.
Aim . The guidelines set out the modern methods of diagnostics and treatment of peptic ulcer and are created for gastroenterologists, primary care physicians, general practitioners, surgeons, ...endoscopists. Key points . The clinical guidelines contain modern views on the etiology and pathogenesis of peptic ulcer, its clinical features, methods of laboratory and instrumental diagnostics, the main approaches to conservative and surgical treatment. They include the criteria for assessment of the quality of medical care, the algorithm of the doctor's actions, as well as information for the patient. Conclusion . Knowledge of modern methods of diagnostics and therapy of peptic ulcers will contribute to improving the results of its treatment.
The use of mechanical pressure gauges as pressure measuring devices is regulated by standard documentation. Also, manometric tubular springs - the sensitive elements of pressure gauges are used in ...various technology fields. Thus, the use of MTS in agricultural machinery allows reducing the traction resistance of tillage machines due to the effect of vibration when interacting with the soil, as well as improving the quality of the soil treatment process by adjusting the stiffness of the rack. This paper presents the results of calculating the stresses and deformations of the ripper shank structure, made in the form of a flexible tubular element when loaded with internal pressure and external force. The active development of the oil and gas industry is currently directed towards the remote territories of the Yamal peninsula and the territories of the Far East, which are characterized by complex natural and climatic conditions of construction. In this regard, it is necessary to develop new approaches and methods of construction in permafrost conditions. The paper presents the results of calculating the stresses and deformations of the structure of the ripper shank, made in the form of a flexible tubular element under loading by internal pressure and external force. The finite element method implemented in the "ANSYS" program was used for research.
Aim.
A clinical description of gastroesophageal reflux disease (GERD) complicated by Barrett’s oesophagus (BO) at inadequate antisecretory therapy and the assessment of functional tests in control of ...conservative treatment.
Key points.
A 63-yo patient with no complaints in a proton pump inhibitor (PPI) therapy was admitted for a follow-up examination for BO-complicated GERD using oesophagogastroduodenoscopy (OGDS) with biopsy, high-resolution oesophageal manometry and 24-h pH-impedance. Endoscopy revealed signs of BO (long segment C1M3), erosive reflux oesophagitis (grade B in Los Angeles classification). Non-contractile oesophagus in manometry. Antisecretory therapy was stated ineffective and subject to correction in 24-h pH-impedance.
Conclusion.
Asymptomatic BO-complicated GERD patients comprise a special cohort. The main challenge to prevent progression into oesophageal adenocarcinoma is an adequate personalised patient management leveraging the modern diagnostic techniques, control of antisecretory treatment and its correction
a situ
.
Aim of the study
. To investigate the esophageal dysmotility, changes in the esophageal mucosa and the immune response depending on the type of refluxate in gastroesophageal reflux disease (GERD) ...patients.
Material and methods
. 68 patients with GERD were recruited: 28 (14 men; mean age, 45.74 ± 2.23 years) nonerosive reflux disease (NERD), 22 (15 men; mean age, 45.0 ± 3.24 years) erosive reflux disease (EE), 18 (13 men; mean age, 47.22 ± 2.95) Barrett’s Esophagus (BE). GERD patients underwent esophageal high-resolution manometry (HRM) with a 22-channel water-perfused catheter and Solar GI system (Medical Measurements Systems, Enschede, the Netherlands), 24-hour impedance and pH monitoring using the Ohmega Ambulatory Impedance pH Recorder (Medical Measurements Systems). We analyzed receptor characteristics of monocyte-derived macrophages in all groups of patients.
Results
. On HRM examination, we showed that DCI (distal contractile integral) in NERD patients was higher than in EE (
p
= 0.088) and BE (
p
= 0.076), also LES RP (lower esophageal sphincter resting pressure) in NERD patients was higher than in EE (
p
= 0.039) and BE (
p
= 0.012). The analysis of reflux characteristics showed that the total reflux time with pH < 4 for BE patients was longer than that for NERD and EE patients. An analysis of receptor characteristics of monocyte-derived macrophages showed the prevalence of CD25 and CD80 expression in all groups of patients.
Conclusion
. An analysis of the phenotype of macrophages derived from blood monocytes of GERD patients revealed a prevalence of М1 macrophages that was typical for the Th1 type of immune response. The degree of esophageal dysmotility was correlated with GERD severity and type.
The movement of a tubular manometric spring that experiences oscillations in the plane of curvature of the central axis in a viscous medium is investigated. The Manometr software package for ...automatic calculation of the damping parameters is developed. Experimental estimation of the reliability of the results obtained is performed.
Foreign bodies in the respiratory tract are rare in adults. Clinical manifestations include hemoptysis among other signs which requires the examination to detect tuberculosis and lung cancer. The ...article describes a clinical case that demonstrates the possibilities of endoscopic diagnostics and treatment in the patient with an X-ray negative foreign body (a cigarette filter) that has been in the lumen of the upper lobar bronchus of the right lung for a long time which caused inflammation in the blocked lobe and mimicking endoscopically central lung cancer.
A mathematical model of the stress-strain state of a curved tube of a non-circular cross-section is presented, taking into account the technological wall thickness variation. On the basis of the ...semi-membrane shell theory, a system of linear differential equations describing the deformation of a tube under the effect of pressure is obtained. To solve the boundary value problem, the method of shooting is applied. The adequacy of the proposed mathematical model is verified by comparison with the experimental data and the results of the calculation of tubes by the energy method.
PDF
