BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU ad...BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.展开更多
In this paper,the fow physics and impact dynamics of a sphere bouncing on a water surface are studied experimentally.During the experiments,high-speed camera photography techniques are used to capture the cavity and f...In this paper,the fow physics and impact dynamics of a sphere bouncing on a water surface are studied experimentally.During the experiments,high-speed camera photography techniques are used to capture the cavity and free surface evolution when the sphere impacts and skips on the water surface.The infuences of the impact velocity(v_(1))and impact angle(θ_(1))of the sphere on the bouncing fow physics are also investigated,including the cavitation evolution,motion characteristics,and bounding law.Regulations for the relationship between v_(1)andθ_(1)to judge whether the sphere can bounce on the water surface are presented and analyzed by summarizing a large amount of experimental data.In addition,the efect ofθ_(1)on the energy loss of the sphere is also analyzed and discussed.The experiment results show that there is a ftted curve of v_(1)=17.5θ_(1)−45.5 determining the relationship between the critical initial velocity and angle whether the sphere bounces on the water surface.展开更多
Multi-Threshold CMOS(MTCMOS) is an effective technique for controlling leakage power with low delay overhead.However the large magnitude of ground bouncing noise induced by the sleep to active mode transition may caus...Multi-Threshold CMOS(MTCMOS) is an effective technique for controlling leakage power with low delay overhead.However the large magnitude of ground bouncing noise induced by the sleep to active mode transition may cause signal integrity problem in MTCMOS circuits.We propose a methodology for reducing ground bouncing noise under the wake-up delay constraint.An improved two-stage parallel power gating structure that can suppress the ground bouncing noise through turn on sets of sleep transistors consecutively is proposed.The size of each sleep transistor is optimized by a novel sizing algorithm based on a simple discharging model.Simulation results show that the proposed techniques achieve at least 23% improvement in the product of the peak amplitude of ground bouncing noise and the wake-up time when compared with other existing techniques.展开更多
Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary av...Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary avenue to explore the pre-inflationary dynamics. Brans-Dicke(BD) loop quantum cosmology(LQC) is one of such theories whose effective background dynamics is considered in this article. Starting with a quantum bounce, we explore the pre-inflationary dynamics of a universe sourced by a scalar field with the Starobinsky potential in BD-LQC. Our study is based on the idea that though Einstein’s and Jordan’s frames are classically equivalent up to a conformal transformation in BD theory, this is no longer true after quantization. Taking the Jordan frame as the physical one we explore in detail the bouncing scenario which is followed by a phase of a slow roll inflation. The three phases of the evolution of the universe, namely, bouncing, transition from quantum bounce to classical universe, and the slow roll inflation, are noted for an initially kinetic energy dominated bounce. In addition, to be consistent with observations, we also identify the allowed phase space of initial conditions that would produce at least 60 e-folds of expansion during the slow roll inflation.展开更多
In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of gravity.The metric assumed here is the flat Friedmann–Robertson...In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of gravity.The metric assumed here is the flat Friedmann–Robertson–Walker space–time and the stress energy tensor is of perfect fluid.Since general relativity(GR)has certain issues with late time cosmic speed up phenomena,here we have introduced an additional matter geometry coupling that described the extended gravity to GR.The dynamical parameters are derived and analyzed.The dynamical behavior of the equation of state parameter has been analyzed.We have observed that the bouncing behavior is mostly controlled by the coupling parameter.展开更多
One-dimensional particle simulations have been conducted to study the interaction between a radio-frequency electrostatic wave and electrons with bouncing motion.It is shown that bounce resonance heating can occur at ...One-dimensional particle simulations have been conducted to study the interaction between a radio-frequency electrostatic wave and electrons with bouncing motion.It is shown that bounce resonance heating can occur at the first few harmonics of the bounce frequency(nω_(b),n=1,2,3,...).In the parameter regimes in which bounce resonance overlaps with Landau resonance,the higher harmonic bounce resonance may accelerate electrons at the velocity much lower than the wave phase velocity to Landau resonance region,enhancing Landau damping of the wave.Meanwhile,Landau resonance can increase the number of electrons in the lower harmonic bounce resonance region.Thus electrons can be efficiently heated.The result might be applicable for collisionless electron heating in low-temperature plasma discharges.展开更多
The “shooting and bouncing rays” (SBR) technique is used to analyze the electromagnetic scattering characters of ocean rough surfaces varying with time. Some numerical results are presented and compared with the met...The “shooting and bouncing rays” (SBR) technique is used to analyze the electromagnetic scattering characters of ocean rough surfaces varying with time. Some numerical results are presented and compared with the method of moments, and some factors, such as the incident angle, polarization and frequency are investigated which influence on electromagnetic scattering characters of ocean rough surfaces.展开更多
In this paper, by using the topological degree method and some limiting arguments, the existence of admissible periodic bouncing solutions for a class of non-conservative semi-linear impact equations is proved.
A solid ball of mass m, size r and spin ω about an axis through its center is dropped freely from a height h on a rough horizontal plane. Assuming its angular momentum is parallel to the horizontal plane upon impact ...A solid ball of mass m, size r and spin ω about an axis through its center is dropped freely from a height h on a rough horizontal plane. Assuming its angular momentum is parallel to the horizontal plane upon impact it bounces repeatedly drifting on a vertical plane. We analyze the kinematics of the bouncing ball assuming the impacts are semi-elastic without slipping. By varying the spin and relevant parameters, a robust Mathematica [1] program enables simulating the trajectories.展开更多
Dynamics of a ball moving in gravitational field and colliding with a moving table is studied in this paper. The motion of the limiter is assumed as periodic with piecewise constant velocity—it is assumed that the ta...Dynamics of a ball moving in gravitational field and colliding with a moving table is studied in this paper. The motion of the limiter is assumed as periodic with piecewise constant velocity—it is assumed that the table moves up with a constant velocity and then moves down with another constant velocity.The Poincaré map,describing evolution from an impact to the next impact,is derived and scenarios of transition to chaotic dynamics are investigated analytically and numerically.展开更多
Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions ...Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions pose significant challenges to reliable CFD predictions.A numerical model of multi-particle SLD coupling breaking,bouncing and splashing behaviors is established to explore the relationship between dynamics behavior and particle size.The results show that the peak value of droplet collection efficiencyβdecreases due to splashing.The bounce phenomenon will make the impact limit S_(m)of the water drops decrease.With the increase of the SLD particle size,the water drop bounce point gradually moves toward the trailing edge of the wing.The critical breaking diameter of SLD at an airflow velocity of 50 m/s is approximately 100μm.When the SLD particle size increases,the height of the water droplet shelter zone on the upper edge of the wing gradually decreases,and the velocity in the Y direction decreases first and then increases in the opposite direction,increasing the probability of SLD hitting the wing again.Large particle droplets have a higher effect on the impact limit S_(m)than smaller droplets.Therefore,in the numerical simulation of the SLD operating conditions,it is very important to ensure the proportion of large particle size water droplets.展开更多
Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is a...Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is analyzed. The dynamic model uses Euler-Bernoulli beam theory for cantilever beam, in which the driving force (or driving moment) of the electromagnetic system is taken into account, and the contact force between moving contact and stationary contact is simulated by the Kelvin-Voigt vis-coelastic...展开更多
文摘BACKGROUND The need for an emergency upgrade of a hospitalized trauma patient from the floor to the trauma intensive care unit(ICU)is an unanticipated event with possible life-threatening consequences.Unplanned ICU admissions are associated with increased morbidity and mortality and are an indicator of trauma service quality.Two different types of unplanned ICU admissions include upgrades(patients admitted to the floor then moved to the ICU)and bounce backs(patients admitted to the ICU,discharged to the floor,and then readmitted to the ICU).Previous studies have shown that geriatric trauma patients are at higher risk for unfavorable outcomes.AIM To analyze the characteristics,management and outcomes of trauma patients who had an unplanned ICU admission during their hospitalization.METHODS This institutional review board approved,retrospective cohort study examined 203 adult trauma patients with unplanned ICU admission at an urban level 1 trauma center over a six-year period(2017-2023).This included 134 upgrades and 69 bounce backs.Analyzed variables included:(1)Age;(2)Sex;(3)Comorbidities;(4)Mechanism of injury(MOI);(5)Injury severity score(ISS);(6)Glasgow Coma Scale(GCS);(7)Type of injury;(8)Transfusions;(9)Consultations;(10)Timing and reason for unplanned admission;(11)Intubations;(12)Surgical interventions;(13)ICU and hospital lengths of stay;and(14)Mortality.RESULTS Unplanned ICU admissions comprised 4.2%of total ICU admissions.Main MOI was falls.Mean age was 70.7 years,ISS was 12.8 and GCS was 13.9.Main injuries were traumatic brain injury(37.4%)and thoracic injury(21.7%),and main reason for unplanned ICU admission was respiratory complication(39.4%).The 47.3%underwent a surgical procedure and 46.8%were intubated.Average timing for unplanned ICU admission was 2.9 days.Bounce backs occurred half as often as upgrades,however had higher rates of transfusions(63.8%vs 40.3%,P=0.002),consultations(4.8 vs 3.0,P<0.001),intubations(63.8%vs 38.1%%,P=0.001),longer ICU lengths of stay(13.2 days vs 6.4 days,P<0.001)and hospital lengths of stay(26.7 days vs 13.0 days,P<0.001).Mortality was 25.6%among unplanned ICU admissions,31.9%among geriatric unplanned ICU admissions and 11.9%among all trauma ICU patients.CONCLUSION Unplanned ICU admissions constituted 4.2%of total ICU admissions.Respiratory complications were the main cause of unplanned ICU admissions.Bounce backs occurred half as often as upgrades,but were associated with worse outcomes.
基金the Fundamental Research Funds for the Central Universities(30918012201)the Fund of the State Key Laboratory(6142604190302).
文摘In this paper,the fow physics and impact dynamics of a sphere bouncing on a water surface are studied experimentally.During the experiments,high-speed camera photography techniques are used to capture the cavity and free surface evolution when the sphere impacts and skips on the water surface.The infuences of the impact velocity(v_(1))and impact angle(θ_(1))of the sphere on the bouncing fow physics are also investigated,including the cavitation evolution,motion characteristics,and bounding law.Regulations for the relationship between v_(1)andθ_(1)to judge whether the sphere can bounce on the water surface are presented and analyzed by summarizing a large amount of experimental data.In addition,the efect ofθ_(1)on the energy loss of the sphere is also analyzed and discussed.The experiment results show that there is a ftted curve of v_(1)=17.5θ_(1)−45.5 determining the relationship between the critical initial velocity and angle whether the sphere bounces on the water surface.
基金Supported by the National Natural Science Foundation of China (No. 6087001)
文摘Multi-Threshold CMOS(MTCMOS) is an effective technique for controlling leakage power with low delay overhead.However the large magnitude of ground bouncing noise induced by the sleep to active mode transition may cause signal integrity problem in MTCMOS circuits.We propose a methodology for reducing ground bouncing noise under the wake-up delay constraint.An improved two-stage parallel power gating structure that can suppress the ground bouncing noise through turn on sets of sleep transistors consecutively is proposed.The size of each sleep transistor is optimized by a novel sizing algorithm based on a simple discharging model.Simulation results show that the proposed techniques achieve at least 23% improvement in the product of the peak amplitude of ground bouncing noise and the wake-up time when compared with other existing techniques.
基金Supported in part by the National Natural Science Foundation of China(NNSCF)under Grant Nos.11375153 and 11675145T.Z.is supported in part by NFSC under Grant No.11675143the Fundamental Research Funds for the Provincial Universities of Zhejiang in China under Grant No.RF-A2019015
文摘Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary avenue to explore the pre-inflationary dynamics. Brans-Dicke(BD) loop quantum cosmology(LQC) is one of such theories whose effective background dynamics is considered in this article. Starting with a quantum bounce, we explore the pre-inflationary dynamics of a universe sourced by a scalar field with the Starobinsky potential in BD-LQC. Our study is based on the idea that though Einstein’s and Jordan’s frames are classically equivalent up to a conformal transformation in BD theory, this is no longer true after quantization. Taking the Jordan frame as the physical one we explore in detail the bouncing scenario which is followed by a phase of a slow roll inflation. The three phases of the evolution of the universe, namely, bouncing, transition from quantum bounce to classical universe, and the slow roll inflation, are noted for an initially kinetic energy dominated bounce. In addition, to be consistent with observations, we also identify the allowed phase space of initial conditions that would produce at least 60 e-folds of expansion during the slow roll inflation.
文摘In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of gravity.The metric assumed here is the flat Friedmann–Robertson–Walker space–time and the stress energy tensor is of perfect fluid.Since general relativity(GR)has certain issues with late time cosmic speed up phenomena,here we have introduced an additional matter geometry coupling that described the extended gravity to GR.The dynamical parameters are derived and analyzed.The dynamical behavior of the equation of state parameter has been analyzed.We have observed that the bouncing behavior is mostly controlled by the coupling parameter.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFE0300406)the National Natural Science Foundation of China(Grant Nos.11975272,12075276,11805133,11705236,and 11375234)。
文摘One-dimensional particle simulations have been conducted to study the interaction between a radio-frequency electrostatic wave and electrons with bouncing motion.It is shown that bounce resonance heating can occur at the first few harmonics of the bounce frequency(nω_(b),n=1,2,3,...).In the parameter regimes in which bounce resonance overlaps with Landau resonance,the higher harmonic bounce resonance may accelerate electrons at the velocity much lower than the wave phase velocity to Landau resonance region,enhancing Landau damping of the wave.Meanwhile,Landau resonance can increase the number of electrons in the lower harmonic bounce resonance region.Thus electrons can be efficiently heated.The result might be applicable for collisionless electron heating in low-temperature plasma discharges.
文摘The “shooting and bouncing rays” (SBR) technique is used to analyze the electromagnetic scattering characters of ocean rough surfaces varying with time. Some numerical results are presented and compared with the method of moments, and some factors, such as the incident angle, polarization and frequency are investigated which influence on electromagnetic scattering characters of ocean rough surfaces.
基金Supported by the NNSF of China(11571249)NSF of JiangSu Province(BK20171275)Supported by the grant of Innovative Training Program of College Students in Jiangsu province(201410324001Z)
文摘In this paper, by using the topological degree method and some limiting arguments, the existence of admissible periodic bouncing solutions for a class of non-conservative semi-linear impact equations is proved.
文摘A solid ball of mass m, size r and spin ω about an axis through its center is dropped freely from a height h on a rough horizontal plane. Assuming its angular momentum is parallel to the horizontal plane upon impact it bounces repeatedly drifting on a vertical plane. We analyze the kinematics of the bouncing ball assuming the impacts are semi-elastic without slipping. By varying the spin and relevant parameters, a robust Mathematica [1] program enables simulating the trajectories.
文摘Dynamics of a ball moving in gravitational field and colliding with a moving table is studied in this paper. The motion of the limiter is assumed as periodic with piecewise constant velocity—it is assumed that the table moves up with a constant velocity and then moves down with another constant velocity.The Poincaré map,describing evolution from an impact to the next impact,is derived and scenarios of transition to chaotic dynamics are investigated analytically and numerically.
基金supported in part by the National Natural Science Foundation of China(No.52276009)。
文摘Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions pose significant challenges to reliable CFD predictions.A numerical model of multi-particle SLD coupling breaking,bouncing and splashing behaviors is established to explore the relationship between dynamics behavior and particle size.The results show that the peak value of droplet collection efficiencyβdecreases due to splashing.The bounce phenomenon will make the impact limit S_(m)of the water drops decrease.With the increase of the SLD particle size,the water drop bounce point gradually moves toward the trailing edge of the wing.The critical breaking diameter of SLD at an airflow velocity of 50 m/s is approximately 100μm.When the SLD particle size increases,the height of the water droplet shelter zone on the upper edge of the wing gradually decreases,and the velocity in the Y direction decreases first and then increases in the opposite direction,increasing the probability of SLD hitting the wing again.Large particle droplets have a higher effect on the impact limit S_(m)than smaller droplets.Therefore,in the numerical simulation of the SLD operating conditions,it is very important to ensure the proportion of large particle size water droplets.
文摘Contact bounce of relay, which is the main cause of electric abrasion and material erosion, is inevitable. By using the mode expansion form, the dynamic behavior of two different reed systems for aerospace relays is analyzed. The dynamic model uses Euler-Bernoulli beam theory for cantilever beam, in which the driving force (or driving moment) of the electromagnetic system is taken into account, and the contact force between moving contact and stationary contact is simulated by the Kelvin-Voigt vis-coelastic...
