Flow Rate Measurement of Gravity Infusion Set and Functional Evaluation of Drop Counter: A Pilot Study

Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate count feature is essential for improving safety in infusion management. This study aimed to verify if the new drop counters could secure accurate flow rate and drip count by conducting actual flow rate measurements using gravimetry and functional evaluation. A drop counter was attached to each drip chamber of the infusion set, and an IV drip was conducted at the 100 ml/h flow rate. The weight of discharged physiological saline was measured to plot trumpet curves. Next, three different types of drop counters were evaluated to determine if they maintained drip count accuracy according to the changes in their position angles. The flow rate errors in all conditions indicated trumpet-like curves, exhibiting an overall error range within ±10% in all observation windows. Although every drop counter successfully detected and measured dripping, it was challenging in some counters to detect dripping when the drip chamber was tilted. In comparing adult and pediatric IV sets, the adult IV set was found to be less likely to detect dripping in the angled position. No significant differences in results were confirmed between high and low flow rates, suggesting that the drop count function would not be affected by the flow rate in the ranges of typical infusion practices. Doppler sensors have a wide range of measurements and high sensitivity;the dripping was detected successfully even when the drip chamber was tilted, probably due to the advantages of these sensors. In contrast, miscounts occurred in those equipped with infrared sensors, which could not detect light intensity changes in tilted positions. Understanding the tendencies in flow rate errors in infusion can be valuable information for infusion management.

COUNTER Release 5新版本规范分析与研究

本文通过介绍COUNTER规范的历史发展、报告视图、元素属性,并对最新版本的更新与特点进行分析研究,以便国内研究者能更方便快捷地了解和应用COUNTER规范。

Experimental investigation on the radiation background inside body counters

In vivo measurement of radioactivity based on various body counters is arguably the leading measure used to determine the distribution and activity of radionuclides in human subjects,such as I-131 in the thyroid,Am-241 in the lungs,and Pb-210 in the skull.Throughout the measurements,the radiation background is the key factor that determines the sensitivity of the counter.Therefore,to facilitate in vivo measurements,a well-designed shielding room is required to create a low-background environment.However,because the compositions of the radiation background are quite complicated,the respective contributions from each source remain obscure,which places a considerable burden on seeking an optimized design of shielding rooms that strikes the optimum balance between the construction cost and background suppression effect.In this study,we conducted a systematic experimental investigation on the radiation background outside and inside four representative body counters with assorted designs using a variety of radiation detectors,including high-purity germanium detectors,CdZnTe detector,radon emanometer,and gamma-ray dosimeter.By carefully controlling the experimental conditions and synergetic analysis of the measurement results,in conjunction with previous studies,we separated and determined the relative contributions induced by environmental radiation(4%),airborne radon and its daughters(2%),the normal radioactivity of human subjects arising from K-40(58%),cosmic rays(12%),and radioactivity in shielding materials and measuring instruments(24%).Furthermore,based on these results,we discuss practical guidelines to design a shielding room for body counters.

Performance Evaluation of Four Commercial Optical Particle Counters

The performances of four optical particles counters, Aerosol Spectrometer (Grimm 1.108), Enviro Check (Grimm 1.107), DustMonit and ParticleScan, were evaluated in laboratory tests employing monodisperse aerosol particles. The study focused on how commercial instruments perform during routine measurements respect to OPC scientific understanding, because it is important for users of such instruments to be aware of their limitations. Measurements were performed using aerosol generated by a Monodisperse Aerosol Generator (MAGE), which produced carnauba wax particles of diameter (1.00 ± 0.08) μm and (1.40 ± 0.15) μm, and monodisperse Polystyrene Latex (PSL) aerosol with nominal diameter of 1.0mm. The results show comparable total particle number concentrations for all the counters, when the count of the first size channel (0.3 - 0.4 μm) for the 1.108 Grimm counter was left out. In the said channel the Grimm counter 1.108 always showed much higher particle counts than those inferred from the tested aerosols. The overcount was proved by the fact that the aerosol sampled in each test on a Nuclepore filter showed no particles in the 0.3 - 0.4 μm range when examined under Scanning Electronic Microscope (SEM). The presence of an artefact produced by the counter was assumed as a likely explanation. For all the counters, the Count Median Diameters (CMDs) of aerosol size distributions, were far below the expected value for the aerosol used. The nearest CMD values to the expected ones were shown by the Grimm 1.107 counter.

Method to Measure Indoor Radon Concentration in an Open Volume with Geiger-Mueller Counters: Analysis from First Principles

A simple method employing a pair of pancake-style Geiger-Mueller (GM) counters for quantitative measurement of radon activity concentration (activity per unit volume) is described and demonstrated. The use of two GM counters, together with the basic theory derived in this paper, permit the detection of alpha particles from decay of and progeny ( 218Po, 214Po) and the conversion of the alpha count rate into a radon concentration. A unique feature of this method, in comparison with standard methodologies to measure radon concentration, is the absence of a fixed control volume. Advantages afforded by the reported GM method include: 1) it provides a direct in-situ value of radon level, thereby eliminating the need to send samples to an external testing laboratory;2) it can be applied to monitoring radon levels exhibiting wide short-term variability;3) it can yield short-term measurements of comparable accuracy and equivalent or higher precision than a commercial radon monitor sampling by passive diffusion;4) it yields long-term measurements statistically equivalent to commercial radon monitors;5) it uses the most commonly employed, overall least expensive, and most easily operated type of nuclear instrumentation. As such, the method is par-ticularly suitable for use by researchers, public health personnel, and home dwellers who prefer to monitor indoor radon levels themselves. The results of a consecutive 30-day sequence of 24 hour mean radon measurements by the proposed GM method and a commercial state-of-the-art radon monitor certified for radon testing are compared.

Fuzzy Reasoning Methods by Choosing Different Fuzzy Counters and Analysis of Effect

Different fuzzy reasoning methods were gave by choosing different fuzzy counters.This article generally introduced the basic structure of fuzzy controller,and compared and analysised the reasoning effect of fuzzy reasoning methods and the effect of computer simulating control basicly on different fuzzy counters.

Accuracy of the automated cell counters for management of spontaneous bacterial peritonitis

AIM: To evaluate the accuracy of automated blood cell counters for ascitic polymorphonuclear (PMN) determination for: (1) diagnosis, (2) efficacy of the ongoing antibiotic therapy, and (3) resolution of spontaneous bacterial peritonitis (SBP). METHODS: One hundred and twelve ascitic fluid samples were collected from 52 consecutive cirrhotic patients, 16 of them with SBP. The agreement between the manual and the automated method for PMN count was assessed. The sensitivity/specificity and the positive/negative predictive value of the automated blood cell counter were also calculated by considering the manual method as the "gold standard" . RESULTS: The mean ± SD of the difference between manual and automated measurements was 7.8 ± 58 cells/mm3, while the limits of agreement were +124 cells/mm3 [95% confidence interval (CI): +145 to +103] and -108 cells/mm3 (95% CI: -87 to -129). The automated cell counter had a sensitivity of 100% and a specificity of 97.7% in diagnosing SBP, and a sensitivity of 91% and a specificity of 100% for the efficacy of the ongoing antibiotic therapy. The two methods showed a complete agreement for the resolution of infection. CONCLUSION: Automated cell counters not only have a good diagnostic accuracy, but are also very effective in monitoring the antibiotic treatment in patients with SBP. Because of their quicker performance, they should replace the manual counting for PMN determination in the ascitic fluid of patients with SBP.

Use of a Public Fishing Area Determined by Vehicle Counters with Verification by Trail Cameras

This study was performed in order to determine visitation at remote areas that would be unaffordable due to logistic reasons. Four TrafxTM vehicle counters, each programmed with different settings, were placed along the lone access road to remotely sense the daily use activities and count accuracy at the New Underwood Lake Public Water Access Area. Use was corroborated during daylight hours with game cameras. Data was stratified between weekdays/weekends due to differences between the two periods. Two counter settings, threshold and delay, were best when set at a value of 8, but a value of 16 for delay provided almost equal results. Overall, there were 38 counts of use per day for a total of 2318 over the 61 day period. This study demonstrated how vehicle counters, in combination with game cameras for verification, can aid managers for determining use in remote access areas. Future work may lead to identifying details for producing a surrogate to traditional angler use surveys.

Comparative Alpha Tracks Counting Using an Optical Microscope and a Spark Counter

In the metrology of radon, an environmental lung carcinogen, the integrated measurements necessary for epidemiological studies are made very often using the tracks detector LR 115 type 2. For dosimetric analysis, the etched tracks from radon alpha particles on this detector are usually counted by means of an optical microscope or a spark counter. An optimal reading of the track densities which must be converted into radon concentrations, can’t be done without a good mastery of the mode of operation and use of these devices. Furthermore, investigations to know as to whether or not each of those can be used to determine radon concentration are necessary. These are the objectives of the present work in which LR 115 samples exposed to radon for at least 3 months, were chemically developed under standard conditions and read. The track densities obtained with the microscope are very much higher than those of the counter for each sample. These results are consistent with those published by other authors. However, each of these devices can be used interchangeably for alpha tracks counting, as both provide radon concentrations with a very good linear correlation coefficient of 0.95 taking into account their respective calibration factors for the reading of this detector. In addition, the saturation phenomenon for the spark counter reading of LR 115 detector occurs beyond 11,000 tr/cm2, a density never reached during our environmental radon measurements.

Aerodynamic Coupling Analysis of Counter⁃rotating Propfan and Inlet Flow Field

Taking a propfan engine as the research object,the CFD method was used for 3D modeling and unsteady slip flow for numerical calculation.The propfan rotation domain and the nacelle outside flow domain were meshed by using the partition splicing grid technology.Used the Reynolds⁃averaged of N⁃S equation,the Reynolds stress term uses the RNG turbulence model;and based on the slip grid method,numerical calculation of the flow field with different Mach numbers,front and rear blade angles and engine state were carried out;and the change law of propeller fan characteristics and the influence of slip flow on the inlet flow field were analyzed.The blade angle was the key parameter of the propeller fan characteristic conditions.When the blade angle increases from 41°to 50°,the thrust coefficient increases by 31.2%,and the power coefficient increases by 33.4%;in the climbing state of the propeller fan,the maximum total pressure distortion at the inlet port of 6.8%;the cross section is less affected by the slip flow of the propfan;and the pressure distribution is relatively uniform,but the area of the flow channel is small.The research results can provide a solution for the matching of the counter⁃rotating propeller fan and the engine and the arrangement of the air inlet measuring rake.

乡村振兴战略下逆城镇化形成动因与推进策略探析

推进逆城镇化,让社会精英到农村发挥引领作用,是实现乡村振兴的重要举措。从乡村振兴战略视角阐述逆城镇化的概念与作用,并基于社会行为学理论,从外部环境和行为主体两方面解析推进逆城镇化形成的动力因素及其作用关系,以此探析逆城镇化的前因后果。研究认为:促进逆城镇化形成与发展的动力可归纳为四个方面,即政府引导力、城市推动力、农村吸引力和基础支撑力;当前应以政府引导力、农村吸引力为着力点,以产业振兴为中心,推动城乡融合发展。基于上述分析,可以从发挥逆城镇化在乡村振兴中的基础作用、发挥产业振兴在逆城镇化中的核心作用、健全促进逆城镇化发展的政策与机制、创造逆城镇化发展的基础条件等方面着手更好地推进逆城镇化。

一种基于多变量卡诺图的自启动方法

在时序逻辑电路的分析或设计过程中,都存在自启动的确认环节。以扭环形计数器的自启动电路设计为例,提出一种基于自定义多变量卡诺图的自启动研究方法,分析了电路没有自启动功能的原因所在,并利用卡诺图具有的化简能力,精简优化自启动电路设计。5变量以上的多变量卡诺图应用,使此方法具有更强的工程实用性。同时,此方法可推广到其他类型时序逻辑电路自启动功能的分析、设计工作中。

雷达波形对抗技术发展预见

随着雷达、电子侦察等传感器技术的进步,对电磁空间的操控从能量、频率向更高维度的波形发展,雷达波形对抗应运而生。阐述雷达波形对抗技术产生的背景、概念内涵和发展现状,同时提出可利用博弈思维建立雷达波形“OODA”回路,通过对雷达波形进行伪装、扰乱和利用以达成制造战场迷雾、创造新质杀伤链的效果。此外,介绍实现雷达波形对抗的波形隐匿、波形重建与利用、波形捷变反侦察等关键技术及原理。从波形管控等3个方面提出雷达波形对抗制胜电磁空间的发展建议。

流气式低本底α/β测量仪的串道特征及干扰修正

研究了一系列α、β金属平面源、粉末源及薄层样法自制面源在流气式低本底α/β测量仪上的串道现象。结果显示:^(90)Sr-^(90)Y金属面源以及 ^(14)C,^(137)Cs,^(90)Sr-^(90)Y, ^(40)K粉末源β对α通道的串道比均在0.1%以下,基本可以忽略不计;α金属平面源串道比大小规律表现为 ^(210)Po<^(209)Po<^(239)Pu<^(239)Pu-^(241)Am混合源<241Am,范围为3.49%~25.4%,发射不同能量粒子的α金属源的串道比差异较大。由于衰变过程产生的内转换电子、俄歇电子以及X射线等在β道产生响应,241Am源的串道比明显高于其他源,241Am粉末源的串道比随单位面积质量厚度增加而增大。α粒子对β通道的串道现象较明显,并与样品制源方式有关,主要是不同制源方式造成的自吸收差异导致的,总体有α粉末源串道比>薄层样法自制α面源>α金属平面源,测量时应重点考虑α粒子对β放射性的串道干扰。通过210Po加标样及牡蛎样品经放化分析制成的电镀源验证,对待测样品源进行一定厚度的铝箔或纸片覆盖,可以有效的减小α粒子对β通道的串道干扰;也可以直接利用串道比对测量计数进行修正,此时需要考虑待测样品源和串道比刻度源的一致性,否则会导致修正结果的偏差较大。

基于雷达自动目标识别技术的反无人机雷达

面对“低慢小”(Low Slow Small, LSS)无人机威胁挑战,反无人机雷达的关键作用日益凸显。在反无人机系统(Countering-Unmanned Aerial Systems, C-UAS)技术中,反无人机雷达作为C-UAS的核心传感器,承担着关键任务,包括探测和导引等。尽管其重要性显而易见,反无人机雷达设计仍然存在概念上的不清晰,例如如何定义LSS无人机目标,以及为何众多反无人机雷达难以探测无人机等问题。通过探讨雷达自动目标识别(Automatic Target Recognition, ATR)技术在反无人机雷达中的应用,从目标特性和探测技术2个方面明确了关键问题。强调了雷达探测的独立过程,将其分为“信号检测”和“目标识别”,并指出反无人机雷达的主要探测对象是LSS无人机目标。ATR性能等级被明确定义,涵盖了“Detection探测”“Classification分类”“Identification识别”“Description描述”4个等级。整合ATR功能显著提升了无人机的探测距离和识别能力,推动了反无人机雷达系统的性能升级。

蜘蛛网流道冷板冷却液对向流锂离子电池散热分析

锂离子电池工作温度过高或温差过大将导致其容量降低和寿命缩短。为了降低其工作温度及温差,设计了一款蜘蛛网流道冷板,采用数值方法对其冷却液对向流锂离子电池散热进行了计算。比较了蜘蛛网流道冷板冷却液对向流与同向流锂离子电池的散热情况,分析了冷却液流量以及冷板内流道夹角、槽深、壁厚对电池散热的影响。结果表明:与冷却液同向流电池相比,冷却液对向流电池最高温度、温差都降低,电池温度分布更加均匀。在0.02~0.06 kg/s区间,随着冷却液流量增大,电池最高温度和温差快速降低,而冷却液压降缓慢增大;当冷却液流量大于0.06 kg/s时,随着冷却液流量增大,电池最高温度和温差缓慢降低,而冷却液压降快速增大。增大流道夹角可使流道在冷板内分布更加均匀,提高冷板散热能力。当冷却液质量流量恒定时,增大流道槽深可使冷却液压降显著减小,但会引起电池最高温度和温差略微升高。随着流道壁厚增大,电池最高温度和温差均呈下降趋势。蜘蛛网流道冷板在流道夹角80°、槽深1 mm、壁厚2 mm、冷却液流量0.06 kg/s对向流冷却条件下,可使锂离子电池3C放电最高温度和温差降至31.02℃和4.54℃。

凝聚核粒子计数器原理与实验研究

针对环境中纳米量级颗粒物浓度检测问题,对凝聚核粒子计数器进行了研究与设计。首先对凝聚核粒子生长原理及检测原理进行了研究,并依据异质核化原理设计了凝聚核粒子计数器的生长装置;其次设计了传感器后级信号处理电路用于解决微弱粒子检测信号抗干扰能力差和测量困难问题;然后设计了基于抗饱和积分PID的控制系统,实现了采样流量的闭环控;最后制研制了凝聚核粒子计数器样机,并开展了流量控制、纳米量级粒子生长及计数实验。实验结果表明,设计的凝聚核粒子计数器,流量稳定性在2%以内,以TSI3772型凝聚核粒子计数器为标准仪器的计数相对误差在±8.5%以内,满足了行业规范要求。

中国与东盟国家反恐合作:理论创新与路径探索

“一带一路”倡议启动十年来,中国与东盟国家在经贸领域的合作不断深入,非传统安全威胁给合作成果带来的威胁日益凸显。东南亚地区的恐怖势力呈现出域内域外整合、与暴力极端组织融合、与有组织犯罪结合的发展新态势。深化在反恐、打击跨境犯罪等领域的合作是中国与东盟国家协调发展、共同应对挑战的必然选择。然而,双方现有合作中面临东盟内部结构性障碍、预防性反恐缺乏、法制建设不均衡以及区域力量制衡等问题,严重阻碍了反恐合作的深入发展。本研究将国际反恐合作问题置于与区域间主义、集体行动等与合作相关的理论所构建的分析框架中进行分析和思考,从合作的达成和合作困难的根本性原因出发,对合作发生的可能性、可行性进行理论分析,从理论与现实相结合的视角审视问题解决的可能途径,并通过该分析框架详细分析中国与东盟国家区域间警务合作中澜湄执法安全合作这一典型案例,为中国与东盟国家化解反恐合作困境提供新的思路。

赫尔德及其同时代人:古典、浪漫、启蒙与反启蒙——乌尔里希·盖尔教授访谈

赫尔德是18世纪德意志重要的思想家,在德意志等西方文学、哲学与其他相关领域享有重要地位。德国康斯坦茨大学盖尔教授是德国著名日耳曼学者,著作等身,长期从事德意志近现代文学研究,尤以在赫尔德研究领域贡献卓著。本文从流派概念出发,围绕赫尔德以及他同时代人,对盖尔教授进行访谈。因为德意志近代文学独具特色,盖尔教授反对用流派概念对这些作家进行标签化的简单划分。而赫尔德在这一独具特色的德意志近代文学中起了举足轻重的作用,对后来德意志文学以及文史哲发展影响深远。

巢与凤:村落环境与乡村振兴背景下的市民下乡——基于广东行政村抽样调查

如何吸引城市人下乡的难题可以归结为“巢”(村落环境)与“凤”(市民下乡)的关系。对广东省312个行政村的随机抽样调查结果表明,只有不到1/3的行政村有下乡市民,而且下乡市民数量的村落分布差异性很大。二元Logistics回归模型显示,整体上“地理区域”和“村里的网络速度”对市民下乡有显著性影响;村落环境对各动机类型(务农、办厂开店、受雇、养老)市民下乡的影响机制各不相同。主要结论:产业自我集聚循环累积效应推动市民下乡,市民下乡具有明显“郊区化”特征,市民下乡“舒适性迁移”特征明显,信息化水平是影响市民下乡的重要因素,市民下乡创业行为具有明显的价值合理性;另外,宗族结构对逆城市化影响的理路值得进一步研究。