scholarly journals Structure of U-Zr-Mo alloy shell after explosive loading

2018 ◽  
Vol 183 ◽  
pp. 03025
Author(s):  
Dmitry Belyaev ◽  
Alexey Aleksandrov ◽  
Yuri Zuyev ◽  
Eugene Kozlov ◽  
Igor Svyatov ◽  
...  

This presentation describes investigation of a thick-wall spherical shell 48 mm in diameter from the alloy of uranium with molybdenum and zirconium, which survived after high-intensity explosive loading. Investigation was performed in the meridional section of the shell to obtain qualitative data on hardness and microhardness, metallurgical inclusions, damage, and also material microstructure. Structural changes are observed to widely present in the shell material. The localized damage observed both at R ≈ 12-14 mm and R ≈ 16-18 mm are the first and second converged spalls, respectively. What is more, in the southern sector the first spall was recompacted with the remelting of a large region of the material in the adjacent layers (region with the enhanced hardness for the first spall). Cracks of the second spall in the northern sector were also recompacted almost completely.

2021 ◽  
Vol 250 ◽  
pp. 03003
Author(s):  
D.A. Belyaev ◽  
A.S. Aleksandrov ◽  
Yu.N. Zuev ◽  
E.A. Kozlov ◽  
A.E. Shestakov ◽  
...  

This paper presents results of metallographic examination of a thick-wall spherical shell from uranium alloyed with iron and germanium. This shell is recovered after low-level explosive loading. Light microscopy, hardness measurement, scanning electron microscopy and X-Ray diffraction study were used to investigate the meridional section of the test shell as this section most completely exhibits the whole variety of structural features associated with explosive loading of the material. Processing, presentation, and analysis of experimental data on volumetric distribution of studied physical quantities were performed with the help of digital panning and color mapping.


Author(s):  
Heather Churchill ◽  
Jeremy M. Ridenour

Abstract. Assessing change during long-term psychotherapy can be a challenging and uncertain task. Psychological assessments can be a valuable tool and can offer a perspective from outside the therapy dyad, independent of the powerful and distorting influences of transference and countertransference. Subtle structural changes that may not yet have manifested behaviorally can also be assessed. However, it can be difficult to find a balance between a rigorous, systematic approach to data, while also allowing for the richness of the patient’s internal world to emerge. In this article, the authors discuss a primarily qualitative approach to the data and demonstrate the ways in which this kind of approach can deepen the understanding of the more subtle or complex changes a particular patient is undergoing while in treatment, as well as provide more detail about the nature of an individual’s internal world. The authors also outline several developmental frameworks that focus on the ways a patient constructs their reality and can guide the interpretation of qualitative data. The authors then analyze testing data from a patient in long-term psychoanalytically oriented psychotherapy in order to demonstrate an approach to data analysis and to show an example of how change can unfold over long-term treatments.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Veria Khosrawipour ◽  
Sören Reinhard ◽  
Alice Martino ◽  
Tanja Khosrawipour ◽  
Mohamed Arafkas ◽  
...  

Background. High‐intensity ultrasound (HIUS) has been studied for the past two decades as a new therapeutic option for solid tumor direct treatment and a method for better chemotherapy delivery and perfusion. This treatment approach has not been tested to our knowledge in peritoneal metastatic therapy, where limited tissue penetration of intraperitoneal chemotherapy has been a main problem. Both liquid instillations and pressurized aerosols are affected by this limitation. This study was performed to evaluate whether HIUS improves chemotherapy penetration rates. Methods. High-intensity ultrasound (HIUS) was applied for 0, 5, 30, 60, 120, and 300 seconds on the peritoneal tissue samples from fresh postmortem swine. Samples were then treated with doxorubicin via pressurized intraperitoneal aerosol chemotherapy (PIPAC) under 12 mmHg and 37°C temperature. Tissue penetration of doxorubicin was measured using fluorescence microscopy on frozen thin sections. Results. Macroscopic structural changes, identified by swelling of the superficial layer of the peritoneal surface, were observed after 120 seconds of HIUS. Maximum doxorubicin penetration was significantly higher in peritoneum treated with HIUS for 300 seconds, with a depth of 962.88 ± 161.4 μm (p < 0.05). Samples without HIUS had a penetration depth of 252.25 ± 60.41. Tissue penetration was significantly increased with longer HIUS duration, with up to 3.8-fold increased penetration after 300 sec of HIUS treatment. Conclusion. Our data indicate that HIUS may be used as a method to prepare the peritoneal tissue for intraperitoneal chemotherapy. Higher tissue penetration rates can be achieved without increasing chemotherapy concentrations and preventing structural damage to tissue using short time intervals. More studies need to be performed to analyze the effect of HIUS in combination with intraperitoneal chemotherapy.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3637
Author(s):  
Xinhui Zhou ◽  
Cuina Wang ◽  
Xiaomeng Sun ◽  
Zixuan Zhao ◽  
Mingruo Guo

This study aimed to compare the effects of high intensity ultrasound (HIU) applied at various amplitudes (20~40%) and for different durations (1~10 min) on the physiochemical and structural properties of goat milk β-lactoglobulin. No significant change was observed in the protein electrophoretic patterns by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Deconvolution and second derivative of the Fourier transform infrared spectra (FTIR) showed that the percentage of β-sheet of goat milk β-lactoglobulin was significantly decreased while those of α-helix and random coils increased after HIU treatment The surface hydrophobicity index and intrinsic fluorescence intensity of samples was enhanced and increased with increasing HIU amplitude or time. Differential scanning calorimetry (DSC) results exhibited that HIU treatments improved the thermal stability of goat milk β-lactoglobulin. Transmission electron microscopy (TEM) of samples showed that the goat milk β-lactoglobulin microstructure had changed and it contained larger aggregates when compared with the untreated goat milk β-lactoglobulin sample. Data suggested that HIU treatments resulted in secondary and tertiary structural changes of goat milk β-lactoglobulin and improved its thermal stability.


2006 ◽  
Vol 101 (2) ◽  
pp. 165-173 ◽  
Author(s):  
V. I. Zel’dovich ◽  
I. V. Khomskaya ◽  
N. Yu. Frolova ◽  
A. E. Kheifets ◽  
V. M. Gundyrev ◽  
...  

2012 ◽  
Vol 56 (12) ◽  
pp. 1894-1905 ◽  
Author(s):  
Dragana Stanic-Vucinic ◽  
Marija Stojadinovic ◽  
Marina Atanaskovic-Markovic ◽  
Jana Ognjenovic ◽  
Hans Grönlund ◽  
...  

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16045-e16045
Author(s):  
Veria Khosrawipour ◽  
Piotr Frelkiewicz ◽  
Sören Reinhard ◽  
Jakub Nicpon ◽  
Tanja Khosrawipour ◽  
...  

e16045 Background: The penetration of chemotherapeutic drugs into metastatic peritoneal nodules remains at levels well below 1 mm, thus significantly limiting the antitumor effect of intraperitoneal chemotherapy (IPC). Recently, high-Intensity ultrasound (HIUS) has been discovered as a potential tool to improve peritoneal diffusion rates. Despite promising preliminary data, basic aspects regarding its technical feasibility, safety and possible limitations remain unclear. This study aims to enhance our current understanding of HIUS and test its applicability using an ex-vivo swine model. Methods: Three postmortem swine were subject to laparotomy with consecutive lavage with 0.9%NaCl saline and HIUS application. For this purpose, a large HIUS radiating pen was introduced into the abdominal cavity and HIUS was applied on two of the four abdominal quadrants for 300 seconds each at an output power of 70 W, 50 % amplitude and 20 kHz frequency. Following the procedure, small intestinal tissue samples were removed for further analyses. Results: In all specimen, peritoneal and subperitoneal layers showed structural changes only visible on a microscopic level. The peritoneal layer was transformed into a mash-like structure while the subperitoneal layer (depth of 142 +/- 28 µm) exhibited microcavities and vascular detachment from surrounding tissues. No bowel rupture or vascular perforations were observed. Conclusions: Our data indicate that HIUS is a technically feasible add-on procedure for IPC with measurable microscopic changes on the peritoneal surface and no apparent bowel toxicity. Pretreatment of the abdominal cavity with HIUS could significantly improve IPC efficacy. Further studies are required to optimize and evaluate this novel approach.


2017 ◽  
Vol 17 (2) ◽  
pp. 279-284 ◽  
Author(s):  
Yuxiang Zhang ◽  
Eric Larose ◽  
Ludovic Moreau ◽  
Grégoire d’Ozouville

Locadiff, an innovative imaging technique based on diffuse waves, has recently been developed in order to image mechanical changes in heterogeneous, geological, or man-made materials. This manuscript reports the on-site application of Locadiff to locate several pre-existing cracks on an aeronautical wind tunnel made of pre-stressed concrete. Using 32 transducers working at ultrasonic frequencies (80–220 kHz) where multiple scattering occurs, we monitor during 15 min an area of 2.5 m×2.5 m of a 35-cm-thick wall. With the wind tunnel in its routine operation, structural changes around the cracks are detected, thanks to their closing or opening due to slight pressure changes. By mapping the density of such microstructure changes in the bulk of the material, locating three pre-existing cracks is properly performed in three dimensions.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Kirsten Hötting ◽  
Nadine Schickert ◽  
Jochen Kaiser ◽  
Brigitte Röder ◽  
Maren Schmidt-Kassow

In animals, physical activity has been shown to induce functional and structural changes especially in the hippocampus and to improve memory, probably by upregulating the release of neurotrophic factors. In humans, results on the effect of acute exercise on memory are inconsistent so far. Therefore, the aim of the present study was to assess the effects of a single bout of physical exercise on memory consolidation and the underlying neuroendocrinological mechanisms in young adults. Participants encoded a list of German-Polish vocabulary before exercising for 30 minutes with either high intensity or low intensity or before a relaxing phase. Retention of the vocabulary was assessed 20 minutes after the intervention as well as 24 hours later. Serum BDNF and salivary cortisol were measured at baseline, after learning, and after the intervention. The high-intensity exercise group showed an increase in BDNF and cortisol after exercising compared to baseline. Exercise after learning did not enhance the absolute number of recalled words. Participants of the high-intensity exercise group, however, forgot less vocabulary than the relaxing group 24 hours after learning. There was no robust relationship between memory scores and the increase in BDNF and cortisol, respectively, suggesting that further parameters have to be taken into account to explain the effects of exercise on memory in humans.


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