Numerical Investigations on Harbor Oscillations Induced by Falling Objects

In this paper,the open-sourced computational fluid dynamics software,OpenFOAM~?,is used to study the fluctuation phenomenon of the water body inside a horizontally one-dimensional enclosed harbor basin with constant water depth triggered by falling wedges with various horizontal falling positions,initial falling velocities and masses.Based on both Fourier transfo rm analysis and wavelet spectrum analysis for the time series of the free surface elevations inside the harbor basin,it is found for the first time that the wedge falling inside the harbor can directly trigger harbor resonance.The influences of the three factors(including the horizontal falling position,the initial falling velocity,and the mass)on the response amplitudes of the lowest three resonant modes are also investigated.The results show that when the wedge falls on one of the nodal points of a resonant mode,the mode would be remarkably suppressed.Conversely,when the wedge falls on one of the anti-nodal points of a resonant mode,the mode would be evidently triggered.The initial falling velocity of the wedge mainly has a remarkable effect on the response amplitude of the most significant mode,and the latter shows a gradual increase trend with the increase of the former.While for the other two less significant modes,their response amplitudes fluctuate around certain constant values as the initial falling velocity rises.In general,the response amplitudes of all the lowest three modes are shown to gradually increase with the mass of the wedge.

Influencing factors of fear of falling among glaucoma patients in west China:a cross-sectional study

AIM:To investigate the current situation and influencing factors of fear of falling in glaucoma patients in western China.METHODS:In this cross-sectional study,glaucoma patients treated in the Ophthalmology Department of West China Hospital of Sichuan University were conducted to investigate the demographic data,visual acuity,visual field,activities of daily living,risk of falling,fear of falling and psychological states.Generalized linear model was used for multivariate analysis with fear of falling as dependent variable and other factors as independent variables.RESULTS:The mean score of the Chinese version modified Fall Efficacy Scale(MFES)was 7.52±2.09 points.Univariate analysis and multivariate analysis showed that the history of falls within one year,visual acuity,visual field,risk of falling,activities of daily living and psychological states had statistically difference on fear of falling(P<0.05).CONCLUSION:Glaucoma patients in west China have relatively high risk of fear of falling.History of falling within 1y,severe visual function impairment,high risk of falling,incapable of independence of daily living,and abnormal psychological state are risk factors of fear of falling among glaucoma patients.

Fish Swimming amid Falling Flowers中的中国绘画元素

中国传统文化传播深刻影响了欧美诗人的诗歌创作,如霍华德·奈莫洛夫受中国传统绘画《落花游鱼图》的影响创作了美国现代诗歌Fish Swimming amid Falling Flowers。霍华德·奈莫洛夫受中国传统绘画的影响主要体现在诗歌创作中对物象移用、意境营造、重返自然、诗意栖居、万物相融、和谐共存的哲思。

A Novel Fall Detection Framework Using Skip-DSCGAN Based on Inertial Sensor Data

With the widespread use of Internet of Things(IoT)technology in daily life and the considerable safety risks of falls for elderly individuals,research on IoT-based fall detection systems has gainedmuch attention.This paper proposes an IoT-based spatiotemporal data processing framework based on a depthwise separable convolution generative adversarial network using skip-connection(Skip-DSCGAN)for fall detection.The method uses spatiotemporal data from accelerometers and gyroscopes in inertial sensors as input data.A semisupervised learning approach is adopted to train the model using only activities of daily living(ADL)data,which can avoid data imbalance problems.Furthermore,a quantile-based approach is employed to determine the fall threshold,which makes the fall detection frameworkmore robust.This proposed fall detection framework is evaluated against four other generative adversarial network(GAN)models with superior anomaly detection performance using two fall public datasets(SisFall&MobiAct).The test results show that the proposed method achieves better results,reaching 96.93% and 92.75% accuracy on the above two test datasets,respectively.At the same time,the proposed method also achieves satisfactory results in terms ofmodel size and inference delay time,making it suitable for deployment on wearable devices with limited resources.In addition,this paper also compares GAN-based semisupervised learning methods with supervised learning methods commonly used in fall detection.It clarifies the advantages of GAN-based semisupervised learning methods in fall detection.

Analysis of the Clinical Interventions for Falls in Elderly Patients in the Community From 2002 To 2022:A Bibliometric Analysis

Objective:To analyze and provide a comprehensive overview of the knowledge structure and research hotspots of clinical interventions for falls in elderly patients in the community.Methods:The search for publications related to clinical interventions for falls in elderly patients in the community from 2002 to 2022 was conducted on the Web of Science Core Collection(WoSCC)database.VOSviewers,CiteSpace,and the R package“bibliometrix”were used to conduct this bibliometric analysis.Results:2091 articles from 70 countries,primarily the United States and Australia,were included.The number of publications related to clinical interventions for falls in elderly patients is increasing yearly.The main research institutions in this field were the University of Sydney,Harvard University,and the University of California.BioMed Central(BMC)Geriatrics was the most popular journal in this field and Journals of the American Geriatrics Society was the most co-cited journal.These publications came from 8984 authors among which author Lord SR had published the most papers and author Tinetti Me had the most co-citations.The main keywords in this research field were“balance,”“exercise,”and“risk factor.”Conclusion:This was the first bibliometric study that comprehensively summarized the research hot spots and development of clinical interventions for falls in elderly patients in the community.This paper aims to provide a reference for scholars and researchers in this particular field.

Falling Tree or Fallen Tree?

《英语辅导报》2000-2001学年度第14期(高二版),7—9单元阶段验收题,笔试部分Ⅱ课本要点A)单项选择题,第9小题: The roof was badlydamaged by a——tree inthe great storm last night. A.fall B.fallen C.fallingD.failed 原参考答案为:B 到底是falling tree还是fallen tree?我们先来分析一下现在分词与过去分词作定语时之语意表达功能: 1.现在分词作定语现在分词作定语从其语意功能看:a)

Residence time distribution of high viscosity fluids falling film flow down outside of industrial-scale vertical wavy wall: Experimental investigation and CFD prediction

The flow behavior of gravity-driven falling film of non-conductive high viscosity polymer fluids on an industrial-scale vertical wavy wall was investigated in terms of film thickness and residence time distribution by numerical simulation and experiment.Falling film flow of high viscosity fluids was found to be steady on a vertical wavy wall in the presence of the large film thickness.The comparison between numerical simulation and experiment for the film thickness both in crest and trough of wavy wall showed good agreement.The simulation results of average residence time of falling film flow with different viscous fluids were also consistent with the experimental results.This work provides the initial insights of how to evaluate and optimize the falling film flow system of polymer fluid.

Numerical study on falling film flowing characteristics of R113 inside vertical tube under different structural conditions

To develop an appropriate falling film evaporation device for organic fluid cogeneration, a numerical study on the gas–liquid two-phase counter-current flow characteristics of R113 inside a vertical tube under different structural conditions was conducted using the Fluent software. The effects of the tube length, tube diameter, and annular gap on the falling film flow characteristics were determined, respectively. The results indicated that under a certain spray density, the falling film thickness in the region of the steady section was almost constant with different structural parameters for the tube diameter, tube length, and annular gap. In addition, a smaller tube diameter resulted in a steadier film flow. When the tube diameter decreased to a specific value, the film thickness showed a uniform distribution along the wall surface. This indicated that a best falling tube diameter exists. Meanwhile, the film fluctuation was enhanced with an increase in the tube length. When the tube length was greater than 1.2 m, the falling film splashed and could not completely wet the wall surface. The film fluctuation was enhanced by decreasing the annular gap, and the film could not be formed when the annular gap was smaller than 1.2 mm.

Homing Guidance Law with Falling Angle and Flying Time Control

In this paper,a new homing guidance method is used to control the flying time and falling angle for guided missiles. Through this approach,it finds the approximate solution to the quadratic equation of time-togo,which is used for the formula derivation of the flying time control command. In this guidance law design,the acceleration rate control command is adopted. The guidance law is composed of a PN guidance command and a flying time control command. Firstly,it obtains a desired falling angle with accurate guidance. Secondly,it introduces to satisfy the constraint of flying time. The flying time control requires an assumption on the future evolution of missile,which is called time-to-go. To cope with the time-varying speed of missiles,a method of compensating the estimation of time-to-go is presented. The new guidance law is evaluated by using a simulation of typical terminal guidance for rocket-propelled torpedo. The simulation results show that the guidance achieves excellent control performance and exhibits insensitivity to initial trajectory parameter over a widen flight envelope.

Simulation of the hydrodynamics and mass transfer in a falling film wavy microchannel

The flow in a liquid falling film is predominantly laminar,and the liquid-side mass transfer is limited by molecular diffusion.The effective way to enhance the mass transfer is to improve the liquid film flow behavior.The falling film behaviors of water,ethanol and ethylene glycol in nine different wavy microchannels were simulated by Computational Fluid Dynamics.The simulation results show that the falling film thickness exhibits a waveform distribution resulting in a resonance phenomenon along the wavy microchannel.The fluctuation of liquid film surface increases the gas-liquid interface area,and the internal eddy flow inside the liquid film also improves the turbulence of liquid film,the gas-liquid mass transfer in falling film microchannels is intensified.Compared with flat microchannel,the CO_(2) absorption efficiency in water in the wavy microchannel is improved over 41%.Prediction models of liquid film amplitude and average liquid film thickness were established respectively.

Co-pyrolysis characteristics of typical components of waste plastics in a falling film pyrolysis reactor

Waste plastics mainly come from MSW and usually exist in the form of mixed plastics. During the co-pyrolysis process of mixed plastics, various plastic components have different physicochemical properties and reaction mechanisms. Considering the high viscosity and low thermal conductivity of molten plastics, a falling film pyrolysis reactor was selected to explore the rapid co-pyrolysis process of typical plastic components(PP, PE and PS).The oil and gas yields and the compositions of pyrolysis products of the three components under different ratios at pyrolysis temperatures were analyzed to explore the co-pyrolysis characteristics of PP, PE, and PS. The study is of great significance to the recycling of waste plastics.

Liquid film falling behaviour on horizontal circular cylinder

The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated.These flows can take three forms:discrete droplets,individual jets,and continuous sheet,and special attention is paid to the effects of the physical properties and geometrical parameters of the first two forms(droplets and jets) because these forms are more important in heat-transfer behaviour and less research has been published for these forms,The flow modes and experimental results were successfully compared with previous experimental literatures,and also the effects of liquid flow rate,tube diameter,and tube spacing on departure site spacing,in both drop and jet modes,were evaluated in the low Galileo number and high viscosity fluid(cooking oil),to help developing criteria for determining falling film modes and their transitions,and to understand the heat transfer characteristics associated with each mode.

Some kinds of falling fuzzy filters of lattice implication algebras

In this paper, the concepts of falling fuzzy(implicative, associative) filters of lattice implication algebras based on the theory of falling shadows and fuzzy sets are presented at first. And then the relations between fuzzy(implicative, associative) filters and falling fuzzy(implicative, associative) filters are provided. In particular, we put forward an open question on a kind of falling fuzzy filters of lattice implication algebras. Finally, we apply falling fuzzy inference relations to lattice implication algebras and obtain some related results.

Heat transfer characteristics of molten plastics in a vertical falling film reactor

The heat transfer efficiency during the pyrolysis process is a key factor to be considered in the design of pyrolysis reactors. In this study, the average apparent heat transfer characteristics of molten plastic pyrolysis in a vertical falling film reactor were explored by experiments and numerical simulation and the apparent heat transfer coefficients were determined. In addition, the temperature distribution and the thickness of the liquid film in the reactor were predicted and the influences of pyrolysis temperatures on the average apparent heat transfer coefficients were discussed.

Influence of Proxies on the Reported Frequency of Falls, Fear of Falling and Activity Restriction in Older People

Introduction: In older populations, the help of a third person may be necessary for a certain number of individuals in order to fill in questionnaires. The influence of this assistance on the collected information can raise questions, among others concerning the concordance between the information provided by the persons themselves and by their proxies, or the introduction of a potential bias. Our study’s objective is to examine, among older people, the differences in the reported frequency of falls, fear of falling and activity restriction due to fear of falling, according to the fact that people had filled in a questionnaire with or without the help of a third person. Methods: The data used come from the secondary analysis of a cross-sectional survey using a self-administered questionnaire and conducted in 2006 in a Belgian semi-rural town among non-institutionalised persons aged 65 years and over. Results: Among the 501 questionnaires, 16.4% were filled in with the help of another person. In bivariate analysis, the persons who needed help reported fall history, fear of falling and activity restriction significantly more often. In multivariable analysis, when considering concurrently the covariates (sex, age, living alone and fall history for fear of falling and for activity restriction), the influence of having received help to fill in the survey was only significant for activity restriction. Conclusion: Our study shows that it is important to know whether or not a person has received help to fill in a questionnaire. This can actually influence the reported frequency of certain outcomes, even, for activity restriction, when considering simultaneously the effect of other covariates. Given the current and future ageing of our populations, it seems that more extensive exploration is needed of the influence of proxies on the collected information about falls, fear of falling and activity restriction among older people.

Viscous falling film instability around a vertical moving cylinder

The present work discusses both the linear and nonlinear stability conditions of a viscous falling film down the outer surface of a solid vertical cylinder which moves in the direction of its axis with a constant velocity.After studying the linear conditions,a generalized nonlinear kinematic model is then derived to present the physical system.Applying the boundary conditions,analytical solutions are obtained using the long-wave perturbation method.In the first step,the normal mode method is used to characterize the linear behaviors.In the second step,the nonlinear film flow model is solved by using the method of multiple scales,to obtain Ginzburg-Landau equation.The influence of some physical parameters is discussed in both linear and nonlinear steps of the problem,and the results are displayed in many plots showing the stability criteria in various parameter planes.

Effects of ABA Content on the Development of Abscission Zone and Berry Falling After Harvesting of Grapes

The commodity price of grape reduces as berry falling after harvest.It is crucial to prevent grape from berry falling during storage.In this article,the structure change of grape cells in the abscission zone was observed,the ABA content and the activities of cellulase and polygalacturonase(PG) were measured,and the relationship of ABA and berry falling was investigated.The results suggest that cells in the abscission zone grow into a separation layer soon after the grapes are cut off.According to the level of development,we designed 6 grades to sort the different development stages.The grade 3 plays an important role in berry falling.ABA enhances the activities of cellulase and polygalacturonase,and accelerates the decomposition of cellulose and pectin,which determines the level of development of abscission zone and berry falling.If ABA ratio is less than 20 ng g-1 fresh weight(FW),the abscission zone is not developed to the grade 3,and the berry falling is effectively stopped.We treated grape bunches with nine plant growth regulators and two chemicals.The results indicated that 2,3,5-triiodobenzoic acid(TIBA) can(a) inhibit the generation of ABA significantly,(b) inactivate the activities of cellulase and PG,(c) delay the development of the grade 3 of abscission zone,and(d) stop berry falling.Indole acetic acid(IAA),gibberellic acid(GA3),naphthalene acetic acid(NAA),6-benzylaminopurine(6-BA),calcium chloride(CaCl2),and potassium permanganate(KMnO4) caused similar results as TIBA.Chlorocholine chloride(CCC),dimethyl amino succinamic acid(B9),chloroethylphosphonic acid(CEPA) and exogenous ABA showed opposite effects.

Physical Activation of Elderly and the Decrease of Falling Risk

A Physical Activation Program was designed and implemented with a particular emphasis in recovering of motor independence, and in an indirect manner;the increase of activities was carried out in a social context in such a way that it allowed isolated elderly to develop their ability to perform daily activities diminishing the burden on their caregivers. 30 people were randomly selected: 15 subjects in the experimental group and 15 in the control group;7 women and 8 men each group. Subjects aged between 60 - 84 years with a mean age of 78 years and a standard deviation of 6.5 were applied in a three-month Physical Activation Program with a 45-min daily sessions. Results obtained showed that physical activity in elderly, systematically improved their amplitude and joint mobility which impact directly and indirectly their quality of life, reducing their risk of falling.

Study on heat transfer for falling liquid film flow with consideration of interfacial evaporation

The interfacial evaporative heat transfer was included in the semi-empirical study of the heat transfer for the falling liquid film flow. The investigations showed that, the inclusion of the interfacial evaporative heat transfer in the turbulent model would lower the predicted convective heat transfer coefficient. Predictions of the new model resulted in a prominent deviation from that predictions of the normal model in the case of large mass flow rate and low wall heat flux. This deviation will be decreased with increasing wall heat flux, such that it will be asymptotic zero at very high wall heat flux. Predictions of the new model agreed well with the current experimental measurements. This study has verified that the Reynolds number is not the sole crucial parameter for heat transfer of falling liquid film flow, and wall heat flux will be another important independent parameter. This result is consistent with our previous studies.

Separation and Purification of Dodecanedioic Acid from Its Homologous Compounds by Falling Film Crystallization

Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including crystallizing time, flow rate of melt and temperature of glycerine bath, on purity of DDDA and crystallizing rate were investigated. Over 99% (by mole) DDDA was obtained for a feed composition of 96% (by mole). The main factors affecting the separation efficiency are flow rate of melt and temperature of glycerine bath. The crystallizing layer of DDDA was further purified by sweating and blasting. A set of optimized operation data are provided for better understanding the mechanism of heat and mass transfer in FFC, and for further industrial application of DDDA purification process.