Analysis of the Efficacy of Humidified High-Flow Nasal Oxygen Therapy Combined with Alveolar Lavage in the Treatment of Patients with Severe Pneumonia Complicated with Respiratory Failure

Objective:To analyze the curative effect of humidified high-flow nasal oxygen therapy combined with alveolar lavage in patients with severe pneumonia and respiratory failure.Methods:120 patients with severe pneumonia complicated with respiratory failure admitted to the Third People’s Hospital of Xining from July 2021 to December 2022 were randomly divided into two groups:group A and group B.The patients in group A were given humidified high-flow nasal oxygen therapy combined with alveolar lavage,whereas those in group B were given humidified high-flow nasal oxygen therapy.The treatment efficacy,blood gas analysis results,and differences in inflammatory mediators were compared between the two groups.Results:The curative effect in group A(96.67%)was significantly higher than that in group B(81.67%),P<0.05;the partial pressure of carbon dioxide(PaCO2),partial pressure of oxygen(PaO2),oxygen saturation(SpO2),and Horowitz index(P/F)of group A were significantly better than group B,P<0.05;the interleukin 6(IL-6),tumor necrosis factor alpha(TNF-α),and C-reactive protein(CRP)levels,white blood cell(WBC)count,serum procalcitonin(PCT),and neutrophil(N)percentage of group A were significantly lower than those of group B,P<0.05.Conclusion:For patients with severe pneumonia complicated with respiratory failure,alveolar lavage,on the basis of humidified high-flow oxygen therapy,can inhibit local inflammation,improve blood gas analysis results,promote disease recovery,and improve the clinical treatment effect。

Recent Progress of Aerosol Light-scattering Enhancement Factor Studies in China

Assessment of the radiative forcing of aerosols in models still lacks sufficient input data for aerosol hygroscopicity. The light scattering enhancement factor [ f(RH, λ)] is a crucial parameter for describing aerosol hygroscopic growth properties.In this paper, we provide a survey of f(RH, λ) studies in China for the past seven years, including instrument developments of humidified nephelometers, ambient f(RH, λ) measurements in China, f(RH, λ) parameterization schemes, and f(RH, λ)applications in aerosol measurements. Comparisons of different f(RH, λ) parameterizations are carried out to check their performance in China using field measurement datasets. We also summary the parameterization schemes for predicting f(RH, λ)with aerosol chemical compositions. The recently developed methods to observe other aerosol properties using f(RH, λ)measurements, such as calculating the aerosol hygroscopicity parameter, cloud condensation nuclei number concentration,aerosol liquid water content, and aerosol asymmetry factor, are introduced. Suggestions for further research on f(RH, λ) in China are given.

Empirical Model to Calculate the Thermodynamic Wet-Bulb Temperature of Moist Air

An equation model for calculating the adiabatic temperature of the wet-bulb thermometer has been obtained empirical fit through a meteorological database, specificly a trough relative humidity and air temperature. A comparison of the results of calculations with the use of this equation and from meteorological database was made. The model deducted of the comparison is valid for a dry bulb temperature range of 3°C to 35°C and for relative humidity percentage in a range of 7% to 97%. Normalized errors are less than 5.5%. It means a maximum variation of 0.55°C from data. However, this variation from error represents only 3.6% of the data sample. The equation model was satisfactory.

REGRESSION OF HEAT AND MOISTURE EXCHANGE DIAGRAM OF SWISS LUWA AIR WASHER

The thesis has changed the heat and moisture exchange curves of Swiss Luwa air washer into double efficiency formulas which are widely used in our country with a computer, and also worked out the regression formula of heat transfer efficiency(X). This has created favourable condition for us to use computer in our calculation of Luwa air washer.

Numerical Simulation and Experimental Studies of Air Treatment Process with Water Spray of One Row Counter Flow

The present work is focused on heat and mass transfer in a direct evaporative air cooler of one row counter flow spray. Models of the two-phase flow in such a air treatment system have been developed. The fields of temperature and relative humidity in spray chamber, as well as the trajectories of sprayed drops have been obtained by numerical method. Experiments aiming at quantifying the system performance and its influence factors have been conducted. It indicates that the increase of air velocity and water/air ratio while the decrease of nozzle density are favorable. The performance of the system of parallel flow spray and counter flow spray have been compared by means of humidifying efficiency. Comparison between numerical simulation and experimental results demonstrate good agreement for outlet air temperature with a maximum error of 8% observed for air relative humidity.

Numerical Simulation and Experimental Studies of Air Treatment Process with Water Spray of One Row Parallel Flow

The main purpose of the present work is to make a further insight into the procedure of heat and mass transfer between water droplets sprayed and air stream in a direct evaporative air cooler used in air-conditioning system in textile mills. The thermodynamic models of the two-phase flow in such a air treatment system have been developed for one row parallel flow spray.The fields of temperature and relative humidity in spraylchamber, as well as the trajectories of sprayed drops have been obtained by calculation. A series of experiment aiming at quantifying the system performance and its influence factors have been conducted. It indicates that the increases of air velocity and water/air ratio while the decrease of nozzle density are favorable. Finally, the comparison between numerical simulation and experimental results have been carried out. Good agreements have been found for outlet air temperaturewhile a maximum error of 10% has been observed for air relative humidity.

Humidifying Effect of Riparian Wetland Park of Shijiazhuang, Hebei Province in Autumn

As an important part of urban green space system, wetland parks have good ecological environment and various landscape resources, which play an irreplaceable role in adjusting the climate, beautifying the environment and maintaining regional ecological balance. Therefore, research on humidifying effect of wetland park is of great significance. Air humidity below the height of 1.5 m above various underlying surfaces was measured in Taiping Riparian Wetland Park of Shijiazhuang. Monitoring time was selected in October 10–12, 2012 and six days among September and October, 2013 which were sunny days without wind(or the speed of wind less than 0.2 m/s). By analyzing the basic distribution regularity of humidity from horizontal and vertical directions at different times in autumn days, humidifying effect of various types of plants could be summarized from the sampled data. The humidifying effect of arbor-grasses can strengthen with the increase of temperature. The humidifying effect is the strongest at 10:00–14:00, then, it weakens after noon and the reduction rate tends to be smaller. Second, the humidity above the height of 0.2 m changes at a small scale and is much lower than that close to ground, which reveals great effect of ground cover plants and soil moisture. According to the monitoring data below the height of 1.5 m, the humidifying effect of shrubs is stronger than that of arbor-grasses. Last, the humidifying effect of surfaces with different land covers from strong to weak are shrubs, arbor-grasses, river. The rational allocation on various types of wetlands with a wide variety of structures can improve the atmospheric environment more effectively.

Humidifying Effect of Green Space during Spring in Yuxi Park of Shijiazhuang City of China

As one of the important parts of urban ecosystem, urban green space plays an irreplaceable role in maintaining the balance of carbon and oxygen, absorbing the pollution and removing dust, killing bacteria, purifying soil and water. To analyze the spatio-temporal changes of humidifying effect of green lands at the spring daytime, the authors monitored the air humidity within 1.8 m high from various underlying surfaces, including arbor-grass lands, shrub lands, herb lands and a cement pavement, from late February to late April in 2015 and 2016, when it was sunny and windless, in the Yuxi park of Shijiazhuang. The results were compared with the monitoring data of a bare land(190 m×120 m) without environmental interventions such as vegetation and water. The results could be summarized as follows:(1) The humidifying effect of green spaces was the weakest at 8:00 a.m. during the late February, whereas it was the strongest at 10:00 a.m.; from late March to late April, the humidifying effect of green spaces strengthened with the increase of air temperature, and the strongest was noted around 12:00-16:00.(2) The humidifying effect of various types of green lands was the strongest close to the ground, and reduced from 0.2 m to 1.8 m. This vertical stratification became apparent after the plants sprouted, the vertical difference of humidifying effect was the most significant in the herb lands, less significant in arbor-grass lands, and least in the shrub lands.(3) Multiple comparison analysis of the humidity data showed that relative humidity of all green lands achieved the significant level(P < 0.05), indicating the strong effect of landscape plants in adjusting atmospheric humidity in spring.(4) The humidifying effect of the artificial lake was more remarkable before the plants sprouted, however, with the rapid growth of plant leaves, theeffect gradually reduced and became even weaker than the effect of vegetation. Although the humidifying effect in spring was weaker than that in summer and autumn, the effect of humidification was more complicated during the growth of green leaves in spring than in summer and autumn. This is useful to construct the theory system of ecological environment effect of green lands in spring, summer and autumn.

Investigation of Inspiratory Circuit Condensation due to Room Temperature in a Heated Humidifier during Mechanical Ventilation

Heating and humidification control during mechanical ventilation is important. Water condensation can occur due to insufficient humidification. Condensation in the breathing circuit can cause various adverse events. In this study, we investigated whether the occurrence of tubing condensation in the breathing circuit could be affected by room temperature using a simulated respiratory circuit with a humidifier. The room temperature was set at 23°C, 25°C, and 27°C, and mechanical ventilation was performed for 8 h. The inspired gas was appropriately heated and humidified according to the manufacturer’s instructions. The weight of the circuit was measured every 2 h at room temperature to estimate the amount of condensation. During the mechanical ventilation, condensation continued to increase at a room temperature of 23°C, but only for the first 2 h at 25°C, and did not occur at 27°C. The room temperature of the indoor environment was one of the factors generating water condensation in the breathing circuit with a humidifier even when a heater wire in the breathing circuit was appropriately operated.

Experimental Evaluation of a Multistage Reciprocating Evaporative Cooler Performance for Varied Climatic Conditions

Current system focuses on design&construction of a multistage reciprocating evaporative cooling test rig.Four packings that are used will undergo the reciprocating action,powered by the cam follower mechanism maintained at an actual rotation speed.Inlet dry bulb temperature&humidity values are varied to replicate the varying climatic conditions,and the output parameters such as cooling load,evaporation rate(ER),humidification efficiency(HE),coefficient of performance(COP)are obtained.Output results showed that as inlet humidity raises,the performance of system drops.With the rise in the camshaft speed or packing velocity,there is an upsurge in the performance until a cam speed of 10 r/min or packing velocity of 0.083 m/s and with further increases in the value,overall performance drops.The system gave a maximum COP,ER,and HE equal to 3.80,73.87%,and 0.53 g/kg respectively.A rise in the inlet air temperature yielded a maximum change in dry bulb temperature of 8.2℃.Overall,results indicated that evaporative cooling is more effective in arid climates than the cold and humid climates.Air quality test is performed to measure CO_(2),Total Volatile Organic Compound(TVOC),and Formaldehyde(HCHO),and it is found that humidified air entering the defined space is of excellent quality.

Effects of ripple cross angles and turbulence models on wet curtain resistance

To study the influence of ripple cross angles on the resistance of wet curtains,wet curtains with different ripple cross angles(45°/45°,45°/15°)were tested on agricultural ventilation equipment performance testing benches,and the static pressure drop under different wind speeds(1-3 m/s)was determined.Four turbulence models(κ-ε,RNGκ-ε,κ-ω,SSTκ-ω)were adopted for numerical simulations of the two types of wet curtain,and the simulations’results were compared with those of experiments.The average errors found are 41.1%,48.7%,27.1%,and 27.8%,respectively,and theκ-ωmodel is found to be the most suitable one for the calculation of wet curtain resistance among the four turbulence models.By using theκ-ωturbulence model,the static pressure drop performances of wet curtains with ripple cross angles 45°/35°and 45°/25°were calculated.Resistance increases with wind speed and ripple cross angles,and a large ripple cross angle has a higher resistance growth rate with increasing wind speed.

黄土高原植被恢复对局地小气候调节效应研究

With the implementation of the Grain for Green Project,vegetation cover has experienced great changes throughout the Loess Plateau(LP).These changes substantially influence the intensity of evapotranspiration(ET),thereby regulating the local microclimate.In this study,we estimated ET based on the Penman-Monteith(PM)method and Priestley-Taylor Jet Propulsion Laboratory(PT-JPL)model and quantitatively estimated the mass of water vapor and heat absorption on the LP.We analyzed the regulatory effect of vegetation restoration on local microclimate from 2000 to 2015 and found the following:(1)Both the leaf area index(LAI)value and actual ET increased significantly across the region during the study period,and there was a significant positive correlation between them in spatial patterns and temporal trends.(2)Vegetation regulated the local microclimate through ET,which increased the absolute humidity by 2.76-3.29 g m^(-3),increased the relative humidity by 15.43%-19.31%and reduced the temperature by 5.38-6.43℃per day from June to September.(3)The cooling and humidifying effects of vegetation were also affected by the temperature on the LP.(4)Correlation analysis showed that LAI was significantly correlated with temperature at the monthly scale,and the response of vegetation growth to temperature had no time-lag effect.This paper presents new insights into quantitatively assessing the regulatory effect of vegetation on the local microclimate through ET and helps to objectively evaluate the ecological effects of the Grain for Green Project on the LP.

Numerical simulation of membrane humidifier with different flow fields for medical application

Medical humidifier is one of the vital instruments for a respiratory patient in hospital,which is used to humidify the required oxygen for respiratory patients.The conventional type of humidifier,bubble humidifier,has some technical problems,including the need to drain condensed water and a lack of accurate control of air or oxygen required by the patient.In contrast,Membrane humidifier has exciting advantages,including the simplicity of the system,the absence of moving parts,very low noise,and the ability to control temperature and humidity.In this study,three configurations,including parallel,cross,and serpentine of a single module of a membrane humidifier according to the person's weight and breathing rate(the range of 10–28 SLPM)are numerically investigated.For validation of numerical models,a membrane humidifier experimental setup test is used.The obtained results indicated that the crossflow configuration for membrane humidifier has a minimum Dew Point Approach Temperature(DPAT)(2<DPAT<5),which confirms that this flow field has better performance than other flow fields.The results show that increasing the volume flow rate increases the DPAT for membrane humidifiers and Water Vapor Temperature Recovery(WVTR).Furthermore,with an increase of 7 L/min of the gas mixture,the relative humidity has decreased by about 30%.This decrease was most outstanding in the cross-flow field and less in the serpentine flow field.

Design Research of a Novel Aftercool-Humidifier Concept for Humid Air Turbine Cycle

Humid air turbine cycle(HAT)has potential of electrical efficiencies comparable to combined cycle,with lower investment cost and NO_(x) emission.The typical heat exchanger network of HAT consists of intercooler(if there is),aftercooler,recuperator,economizer and humidifier,which brings higher efficiency but makes the system more complex.To simplify HAT layout,a novel humidifier concept is proposed by integrating the aftercooler into traditional counter-current humidifier.Based on this concept,a one-dimensional model including pressure drop and exergy calculation is established to distinguish the thermodynamic and hydrodynamic characteristics,and then the structural parameters,such as the number of rows and columns,tube diameter,pitch and type for a micro HAT are identified.The results show that the aftercool-humidifier plays the same role as original aftercooler and humidifier,and can match the in-tube air,out-tube air and water stream well with lower volume.In the case of micro HAT cycle,the volume of heat and mass transfer area can be reduced by 47%compared with traditional design.The major thermal resistance occurred in the convection heat transfer process inside the tube;however,using enhanced tube cannot effectively improve the compactness of device.