Motion forecast of intelligent underwater sampling apparatus —— Part II: CFD simulation and experimental results

1971-1979The part II of the paper adopts the steady-state superposition algorithm proposed in Part I to simulate the vertical surfacing motion and the horizontal drift of the intelligent underwater sampling apparatus (IUSA) under sea current, in order to figure out the surfacing time and horizontal recovery range on the surface of the sea. Through dividing the surfacing process into a number of infinitesimal segments, the velocity, fluid force and displacement of the IUSA are obtained by resorting to Computational Fluid Dynamics (CFD) software, and the procedure of pre-treatment, solver and post-treatment of Fluent is presented in detail. Simulation results based on SolidWorks and FLUENT are compared which also show the proposed algorithm can meet the requirements of the motion forecast of the IUSA. Preliminary experimental results in East Lake validate that the theoretical algorithm and the computational method are effective within the allowable error range, which can guide the mission operator to recover the IUSA on the broad sea area

Effect of Deformation on Precipitation and the Microstructure Evolution during Multistep Thermomechanical Processing of Al-Zn-Mg-Cu Alloy

In order to obtain fine grained structure efficiently, a new multi-step rolling process (MSR: pre-deformation + intermediate annealing + hot deformation) was applied in Al-Zn-Mg-Cu plates. Conventional hot rolling (CHR) was also carried out as a contrast experiment. The evolution of microstructures and improvement of mechanical properties were analyzed by optical microscope, scanning electron microscope, transmission electron microscope, X-ray diffractometer, and tensile tests. The results show that the MSR process can obtain finer longitudinal grain size and better mechanical properties than CHR, which can be explained as follows: spheroidization of precipitates wrapped by high density dislocations could be promoted by increased pre-deformation; numerous ordered substructures were formed during short-period intermediate annealing at high temperature; in the subsequent hot rolling process, the retained spherical precipitates pinned dislocations and boundaries. With the increase of accumulated strain, low angle grain boundaries gradually transformed into high angle grain boundaries, leading to grain refinement. With the increased pre-deformation (MSR1 20 + 60%, MSR2 40 + 40%, MSR3 60 + 20%), the effect of grain refinement and plasticity improvement gradually weakened. The optimum thermomechanical process (MSR1 solid solution + pre-deformation (300 °C/20%) + intermediate annealing (430 °C/5 min) + hot deformation (400 °C/60%)) was obtained, which can increase elongation by ~25% compared with the CHR process, while maintaining similar high strength for reduced longitudinal grain size

A Systematic Review of the Anti-Inflammatory and Immunomodulatory Properties of 16 Essential Oils of Herbs

Background. Inflammation is a host defense mechanism in the body after it is infected and damaged. If inflammation is not treated in time, then it may cause a variety of diseases, such as cancer and autoimmune diseases. Herbal essential oils are natural extracts that can suppress inflammation effectively and are expected to be used in therapeutic drugs for anti-inflammatory diseases in the future. Aim of the review. We review the anti-inflammatory and immunomodulatory effects of essential oils derived from 16 herbs. Materials and methods. We searched the literature of the fields of anti-inflammatory and immunomodulatory herbal essential oil activity published in English within the past five years via databases (PubMed, EMBASE, Scopus, and The Web of Science). Results. A total of 1932 papers were found by searching, and 132 papers were screened after removing duplicates and reading article titles. Fifteen articles met the requirements to be included in this review. Among those selected, 11 articles reported in vivo research results, and 10 articles showed research results. Conclusion. Essential oils extracted from herbs can reduce inflammation by regulating the release of inflammatory cytokines involved in multiple signalling pathways. Herbal essential oils are expected to be developed as anti-inflammatory drugs

Characterization of Precipitation in 7055 Aluminum Alloy by Laser Ultrasonics

After different rolling conditions, four 7055 aluminum alloy samples with different precipitation sizes were measured by scanning electron microscope, transmission electron microscope and laser ultrasonic. The attenuation coefficients of ultrasound measured by laser ultrasonic were calculated in the time domain, frequency domain and wavelet denoising, respectively. The relationship between the precipitate size and attenuation coefficient was established. The results show that the attenuation of the ultrasonic wave is related to the size of the precipitated phase; this provides a new method for rapid non-destructive testing of the precipitation of aluminum alloys

The impact of nurse-led nonpharmacological multidisciplinary holistic nursing care on fatigue patients receiving hemodialysis: a randomized, parallel-group, controlled trial

Abstract Background Fatigue is a symptom characterized by an elevated prevalence in patients undergoing hemodialysis, which may cause extreme mental and muscular debilitation, significantly influencing social interaction, life quality and well-being. However, the significance of fatigue to patients undergoing hemodialysis has not been recognized yet, and prevention and management of fatigue in this population have not been thoroughly investigated. Additionally, previous studies mainly focused on muscular fatigue, while mental fatigue has been seldom discussed. This study aims to investigate the interaction between nurses and multidisciplinary of nonpharmacological integrated care interventions (NICIs) and assess the impact of fatigue on patients undergoing hemodialysis. Methods The integrative nonpharmacological care interventions in this study included walking, motivational interviewing (MI) and health education regarding behavioral self-management. A single-center randomized controlled trial was conducted in the dialysis center of the nephrological department in a tertiary affiliated hospital of medical university from January to June 2019. A total of 118 patients were selected and randomly divided into the intervention group (IG) and the control group (CG). Four patients dropped out during the study, and 114 patients were enrolled for the eventual analysis. The 60 patients in the IG received routine nursing combined with integrated care interventions, while the 54 patients in the CG received routine nursing only. This study lasted for six months. Results The experimental group exhibited significant reductions of overall fatigue (2.26 vs. 0.48), mental fatigue (1.41 vs. 0.54), muscular fatigue (2.13 vs. 0.75), and some biochemical indicators (e.g., serum urea) (P<0.05), compared with the CG. Conclusions Nurses and multidisciplinary teams have been demonstrated to play a key role and interplay function in chronic disease management. Hence, the nurse-led multidisciplinary NICIs significantly alleviated total fatigue (muscular fatigue and mental fatigue) and improved other parameters. Trial registration ChiCTR-IOR-16008621 (March 18, 2016

Nuclear Equation of state for Compact Stars and Supernovae

International audienceThe equation of state (EoS) of hot and dense matter is a fundamental input to describe static and dynamical properties of neutron stars, core-collapse supernovae and binary compact-star mergers. We review the current status of the EoS for compact objects, that have been studied with both ab-initio many-body approaches and phenomenological models. We limit ourselves to the description of EoSs with purely nucleonic degrees of freedom, disregarding the appearance of strange baryonic matter and/or quark matter. We compare the theoretical predictions with different data coming from both nuclear physics experiments and astrophysical observations. Combining the complementary information thus obtained greatly enriches our insights into the dense nuclear matter properties. Current challenges in the description of the EoS are also discussed, mainly focusing on the model dependence of the constraints extracted from either experimental or observational data (specifically, concerning the symmetry energy), the lack of a consistent and rigorous many-body treatment at zero and finite temperature of the matter encountered in compact stars (e.g. problem of cluster formation and extension of the EoS to very high temperatures), the role of nucleonic three-body forces, and the dependence of the direct URCA processes on the EoS