Thermomechanical Energy Converters for Harvesting Thermal Energy:A Review

Thermal energy,i.e.,the electromagnetic energy in the infrared range that originates from the direct solar radiation,outgoing terrestrial radiation,waste heat from combustion of fuels,heat-emitting electrical devices,decay of radioactive isotopes,organic putrefaction and fermentation,human body heat,and so on,constitutes a huge energy flux circulating on the earth surface.However,most energy converters designed for the conversion of electromagnetic energy into electricity,such as photovoltaic cells,are mainly focused on using a narrow part of the solar energy lying in the visible spectrum,while thermomechanical engines that are fueled by heat in the broad energy range and then convert it into mechanical work or store it as mechanical deformation,are paid less attention.Although the efficiency of thermomechanical devices is relatively low,they can be applied to collect waste heat which otherwise contributes to negative climate changes.In this review,operational principles of thermomechanical energy converters and a description of basic devices and materials that utilize thermal energy are given.In addition to conventional macroscopic engines,based on thermoacoustic,thermomagnetic,thermoelastic,hydride heat converters,and shape memory alloys,the emergent devices are described which are classified as smart actuators,breathing frameworks,thermoacoustic micro-transducers,nanomechanical resonators,plasmomechanical systems,and optothermal walkers.The performance of the different types of thermomechanical energy converters is described and compared.

Enhanced sampling for lipid-protein interactions during membrane dynamics

The inflexible concept of membrane curvature as an independent property of lipid structures is today obsolete.Lipid bilayers behave as many-body entities with emergent properties that depend on their interactions with the environment.In particular,proteins exert crucial actions on lipid molecules that ultimately condition the collective properties of the membranes.In this review,the potential of enhanced molecular dynamics to address cell-biology problems is discussed.The cases of membrane deformation,membrane fusion,and the fusion pore are analyzed from the perspective of the dimensionality reduction by collective variables.Coupled lipid-protein interactions as fundamental determinants of large membrane remodeling events are also commented.Finally,novel strategies merging cell biology and physics are considered as future lines of research.

Diverticulitis is a population health problem:Lessons and gaps in strategies to implement and improve contemporary care

The disease burden of diverticulitis is high across inpatient and outpatient settings,and the prevalence of diverticulitis has increased.Historically,patients with acute diverticulitis were admitted routinely for intravenous antibiotics and many had urgent surgery with colostomy or elective surgery after only a few episodes.Several recent studies have challenged the standards of how acute and recurrent diverticulitis are managed,and many clinical practice guidelines(CPGs)have pivoted to recommend outpatient management and individualized decisions about surgery.Yet the rates of diverticulitis hospitalizations and operations are increasing in the United States,suggesting there is a disconnect from or delay in adoption of CPGs across the spectrum of diverticular disease.In this review,we propose approaching diverticulitis care from a population level to understand the gaps between contemporary studies and real-world practice and suggest strategies to implement and improve future care.

中国疫苗供应管理现状及挑战

目的分析全国31个省(自治区、直辖市)和新疆生产建设兵团(以下简称“兵团”)的疫苗供应管理现状,总结我国疫苗供应管理的经验及面临的挑战,为疫苗供应管理决策提供参考。方法对全国31个省(自治区、直辖市)的省(自治区、直辖市)级疾病预防控制中心和兵团疾病预防控制中心进行机构问卷调查,调查内容为疫苗供应管理情况。结果全国31个省(自治区、直辖市)和兵团均出现过疫苗供应不及时的情况,供应延迟的平均天数普遍较长。疫苗配送的及时性总体良好。相比东中部地区,西部地区更需要采购应急疫苗。结论我国疫苗配送的及时性总体良好,对疫苗需求把控准确。但部分疫苗供应紧张,二类疫苗退出机制有待建立,西部地区在疫苗调动及库存把控方面有较大提升空间。

日本“Emergent系统”的研究

本文介绍了日本文部省重点科学研究课题“Emergent系统”的立题背景，研究的出发点，所设立的基础研究项目，及研究的进展．

Modelling and stability analysis of emergent behavior of scalable swarm system

In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the neighbors in the positive visual set of individuals) resulting from the individual motion to one or two farthest neighbors in its positive visual set; the second layer describes the emergent aggregating swarm behavior resulting from the individual motion to its local goal position. The scale of the swarm will not be limited because only local individual information is used for modelling in the two-layer topology. We study the stability properties of the swarm emergent behavior based on Lyapunov stability theory. Simulations showed that the swarm system can converge to goal regions while maintaining cohesiveness.

Reducing Uncertainties in Climate Projections with Emergent Constraints:Concepts, Examples and Prospects

Models disagree on a significant number of responses to climate change,such as climate feedback,regional changes,or the strength of equilibrium climate sensitivity.Emergent constraints aim to reduce these uncertainties by finding links between the inter-model spread in an observable predictor and climate projections.In this paper,the concepts underlying this framework are recalled with an emphasis on the statistical inference used for narrowing uncertainties,and a review of emergent constraints found in the last two decades.Potential links between highlighted predictors are explored,especially those targeting uncertainty reductions in climate sensitivity,cloud feedback,and changes of the hydrological cycle.Yet the disagreement across emergent constraints suggests that the spread in climate sensitivity can not be significantly narrowed.This calls for weighting the realism of emergent constraints by quantifying the level of physical understanding explaining the relationship.This would also permit more efficient model evaluation and better targeted model development.In the context of the upcoming CMIP6 model intercomparison a growing number of new predictors and uncertainty reductions is expected,which call for robust statistical inferences that allow cross-validation of more likely estimates.

Moving contact line problem: Advances and perspectives

The solid-liquid interface, which is ubiquitous in nature and our daily life, plays fundamental roles in a variety of physical-chemical-biological- mechanical phenomena, for example in lubrication, crystal growth, and many biological reactions that govern the building of human body and the functioning of brain. A surge of interests in the moving contact line （MCL） problem, which is still going on today, can be traced back to 1970s primarily because of the exis- tence of the ＂Huh-Scriven paradox＂. This paper, mainly from a solid mechanics perspective, describes very briefly the multidisciplinary nature of the MCL problem, then summarizes some major advances in this exciting research area, and some future directions are presented.

Effect of tranexamic acid on the treatment of patients with upper gastrointestinal bleeding: A double-blinded randomized controlled clinical trial

Objective:To determine the efficacy of tranexamic acid(TXA)in the management of acute upper gastrointestinal(GI)bleeding.Methods:A total of 70 patients with acute upper GI bleeding were included in this double-blinded randomized controlled clinical trial from September 2018 to December 2018.Patients were divided into the control group(received fluid therapy and intravenous infusion of pantoprazole,35 cases)and the TXA group(received intravenous TXA besides the treatment of control group,35 cases).Rebleeding,admission duration,and need for blood transfusion were compared between the two groups.Results:Fifteen patients(42.9%)in the TXA group and 10 patients(28.6%)in the control group stayed in hospital for more than 3 days during their admission(P=0.21).Rebleeding occurred in 8 patients(22.9%)and 5 patients(14.3%)of the TXA group and the control group,respectively(P=0.35).More patients in the TXA group(21 cases,60%)received blood transfusion than the control group(8 cases,22.9%)(P=0.02).Conclusions:TXA did not improve the outcome of patients with acute upper GI bleeding.

Symmetric Equations for Evaluating Maximum Torsion Stress of Rectangular Beams in Compliant Mechanisms

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the crosssection(i.e., the thickness and the width). After reviewing the available equations, two thickness-to-width ratio Independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design Insights are obtained. These equations, together with the previous work on symmetric equations for calculating torsional compliance, provide a convenient and effective way for designing and optimizing torsional beams in compliant mechanisms.

Real-time online rescheduling for multiple agile satellites with emergent tasks

The emergent task is a kind of uncertain event that satellite systems often encounter in the application process.In this paper,the multi-satellite distributed coordinating and scheduling problem considering emergent tasks is studied.Due to the limitation of onboard computational resources and time,common online onboard rescheduling methods for such problems usually adopt simple greedy methods,sacrificing the solution quality to deliver timely solutions.To better solve the problem,a new multi-satellite onboard scheduling and coordinating framework based on multi-solution integration is proposed.This method uses high computational power on the ground and generates multiple solutions,changing the complex onboard rescheduling problem to a solution selection problem.With this method,it is possible that little time is used to generate a solution that is as good as the solutions on the ground.We further propose several multi-satellite coordination methods based on the multi-agent Markov decision process(MMDP)and mixed-integer programming(MIP).These methods enable the satellite to make independent decisions and produce high-quality solutions.Compared with the traditional centralized scheduling method,the proposed distributed method reduces the cost of satellite communication and increases the response speed for emergent tasks.Extensive experiments show that the proposed multi-solution integration framework and the distributed coordinating strategies are efficient and effective for onboard scheduling considering emergent tasks.

The Supernetwork Model of Social Networking Services

The unique ways of information organization and dissemination was examined through the microblog and the real-name social network as the representatives of the new virtual social networks. In order to discuss the interrelation and interaction of the two dimensions-topic and user, a supernetwork model was established based on the supernetwork research method. Through the actual data, a supernetwork topology diagram and the changing rule of user participation were attained. And it was concluded that the key factor of dealing with emergent online public sentiment should start with affecting the opinions of key figures, whose opinions would further affect the public opinions.

Novel method of primary endoscopic realignment for high-grade posterior urethral injuries:A case report

BACKGROUND A male urethral disruption injury is a urological emergency.Primary endoscopic realignment(PER)refers to reestablishment of urethral alignment via indwelling urethral catheter by cystoscope,which is recommended as the optimal emergent treatment approach for reducing the likelihood of complications following injury.However,the prior literature suggests the success rate of PER to be relatively low due to complicated urethral disruption.We report a modified PER approach that serves to improve both the success rate and safety of the treatment.CASE SUMMARY A 19-year-old male patient presented with multiple pelvic fractures and complete urethral disruption following a high-velocity traffic accident.The patient’s abdominal computed tomography and retrograde urethrography results revealed complete urethral disruption at the bulbar urethra,with hematoma and contrast medium extravasation that extended into the extraperitoneal space.The conventional retrograde PER by cystoscope failed due to severe disruption and considerable hematoma.Modified simultaneous antegrade and retrograde PER was performed by means of semi-rigid ureteroscopy via a suprapubic Foley catheter and cystoscopy via the external urethra.An antegrade guidewire was passed through the bladder neck and then pulled out through the external urethral meatus with a cystoscope.Urethral continuity was achieved after a 16-Fr silicone Foley catheter was indwelled into the bladder along the guidewire.The patient recovered well,achieving voiding continence and avoiding further operation for urethral stricture.CONCLUSION Modified PER via suprapubic Foley catheter represents a promising and safe treatment approach in patients with posterior urethral injuries.

Hidden Symmetries for Thermodynamics and Emergence of Relativity

Erik Verlinde recently proposed an idea about the thermodynamic origin of gravity.Though this is abeautiful idea, which may resolve many long standing problems in the theories of gravity, it also raises many otherproblems.In this article I will comment on some of the problems of Verlinde’s proposal with special emphasis on thethermodynamical origin of the principle of relativity.It is found that there is a large group of hidden symmetries ofthermodynamics, which contains the Poincare group of the spacetime for which space is emergent.This explains thethermodynamic origin of the principle of relativity.

Hypersphere World-Universe Model. Tribute to Classical Physics

This manuscript summarizes the results of Classical Physics before Quantum Mechanics and Hypotheses proposed by classical physicists from the 17th until the beginning of 21st century. We then proceed to unify these results into a single coherent picture in frames of the developed Hypersphere World-Universe Model (WUM). The Model proposes 5 types of Dark Matter particles and predicts their masses;models the origin, evolution, and structure of the World and Macroobjects;provides a mathematical framework that ties together a number of Fundamental constants and allows for direct calculation of their values.

Unusual association of Axenfeld-Rieger syndrome and wandering spleen:A case report

BACKGROUND Axenfeld-Rieger syndrome(ARS)is an autosomal dominant genetic disease characterized by ocular developmental disorders and its association with torsion of wandering spleen(WS)has not been reported to date to the best of our knowledge.This study aimed to describe a rare case of ARS observed at our emergency department.CASE SUMMARY A 25-year-old female presented with a constant lower abdominal pain of increasing severity.Diagnostic computed tomography with intravenous contrast material showed a non-homogenously enhanced splenic parenchyma with a twisted vascular pedicle.Further,an emergent laparoscopic exploration was performed,and an ischemic spleen without its normal ligamentous attachments was noted.Notably,the spleen did not regain its normal vascularity after detorsion;thus,we performed the laparoscopic total splenectomy.The postoperative course was uneventful,and the patient was discharged on the 5th postoperative day.This case demonstrates a rare association of WS and ARS.CONCLUSION Early diagnosis of WS in the emergency department is important to prevent pedicle torsion or splenic necrosis and to avoid splenectomy.

The Emergent Salt Diapirs in the East Zagros, Iran

The emergent salt diapirs of the east Zagros, Iran have been investigated by their structural positions. The study area is including of Zagros orogeny belt and Persian Gulf that both of them have been formed on northeastern part of Arabian plate. There are 84 emergent salt diapirs that originated from Hormuz formation with Infra-Cambrian to Cambrian age. Based on location, shape and orientation of the emergent salt domes in the east Zagros hinterland and Persian Gulf foreland basin, internal motivation forces in the salt deposits has been predominant compared to later tectonic forces. In the other words, most of the emergent salt diapirs are pre-orogenic diapirs and they had got prominent role as pines in determining the shape and location of next structures during to the Zagros orogeny. Finally, Neogene continental collision has a supplementary role to diapirism and salt reactivation. However there are an evidence to syn-orogenic emergent diapirs that they have got an important role in the progressive deformation.

Mathematical Overview of Hypersphere World-Universe Model

The Hypersphere World-Universe Model (WUM) provides a mathematical framework that allows calculating the primary cosmological parameters of the World which are in good agreement with the most recent measurements and observations. WUM explains the experimental data accumulated in the field of Cosmology and Astroparticle Physics over the last decades: the age of the World and critical energy density;the gravitational parameter and Hubble’s parameter;temperatures of the cosmic microwave background radiation and the peak of the far-infrared background radiation;the concentration of intergalactic plasma and time delay of Fast Radio Bursts. Additionally, the model predicts masses of dark matter particles, photons, and neutrinos;proposes new types of particle interactions (Super Weak and Extremely Weak);shows inter-connectivity of primary cosmological parameters of the World. WUM proposes to introduce a new fundamental parameter Q in the CODATA internationally recommended values. This paper is the summary of the mathematical results obtained in [1]-[4].

Evolution of emergent C-points,L-lines,and C-lines in free space

Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical examples.It is shown that there exist C-points,L-lines,in particular,C-lines in incoherently superimposed two-dimensional wavefields.Usually,the C-lines are unstable and disappear during the free-space propagation.The motion,pair creation-annihilation process of the emergent C-points,as well as the distortion of the L-lines may take place,and the degree of polarization of the emergent C-points varies upon propagation and may be less than 1.

Percutaneous Dilational Tracheostomy in the Emergent Setting

Objective: Since its inception, the use of the percutaneous dilational tracheostomy (PDT) has been contraindicated in the setting of an emergent airway. Emerging in the literature are several cases of successful emergent PDTs. Here we present our experience with the use of PDT in managing emergent airways. Study Design: All patients who underwent emergent PDT, using the Ciaglia Blue Rhino Introducer Set (Cook Critical Care, Bloomington,IN), in an academic county hospital setting between February 2010 and May 2012 were included in the study. Electronic medical records were reviewed for demographic and procedural data. Results: Twelve patients were included in the study with ages ranging from 20 to 87 (mean 57) years-old. The most common reason for emergent airway was trauma (7 patients), followed by obstructing neck mass (2 patients), septic shock (2 patients), and angioedema (1 patient). Seven PDTs were performed in the OR, four at bedside and one in the ER. Three of the 12 patients had emergent cricothyroidotomies in place that malfunctioned, requiring emergent conversion. No patients suffered from short term complications. One patient developed a neck abscess at the site of the PDT one month post operatively, two patients had accidental decanulation post operatively, and both were replaced without complication. Conclusions: PDT can be used in the emergent setting in the hands of trained practitioners with minimal complications. A larger, prospective trial is needed to make conclusions regarding patient care.