Two-way Valve Research Articles

ABOUT THE USE OF DIGITAL HYDRAULIC VALVES IN INDUSTRY

The article discusses digital hydraulic valves, which are an innovative alternative to traditional proportional analog valves. Digital hydraulics utilize a combination of simple, reliable, and inexpensive ON/OFF type valves, offering high precision in flow and pressure control through programmable logic controllers. The main advantage of such systems is the reduction in energy consumption, as they eliminate the need for constant pump operation and have no internal leakage. The article highlights the economic benefits of digital valves, including lower initial investments due to their lower cost compared to proportional counterparts. Importantly, if one valve fails, the system remains operational, as the failure of individual components does not critically affect overall performance. Special attention is given to coding schemes and control methods, particularly binary coding and pulse number modulation. Binary coding allows for significantly improved regulation accuracy with a minimal number of valves and ensures system fault tolerance. The use of parallel-connected valves, which offer a wide range of states, allows precise control of flows and pressures without the need for switching after the desired positions are set. Additionally, digital hydraulic systems provide fast response times and precise control, making them effective for various industrial applications. Further research in this area could lead to the development of new technological solutions and broader implementation in the industry. The article also covers the technical aspects of such systems, particularly pulse-width modulation, the most common approach to controlling two-way valves. PWM achieves high regulation accuracy through frequency modulation, although low switching frequencies may cause pressure pulsations, which must be compensated through specialized system design or damping devices. In conclusion, digital hydraulic valves represent a promising solution for increasing the efficiency and reliability of hydraulic systems in modern industries, with the potential for significant reductions in energy consumption and operational costs.

Effect of Breathing Room Air Through a Two-Way Non-Rebreathing Valve on HRV in BI and NBI College-Aged Students

Behavioral inhibition (BI) is a temperament associated with increased vulnerability to stress compared to non-behaviorally inhibited (NBI) individuals. Heart-rate variability (HRV) analysis to assess physiological stress has been growing in popularity due to its association with crucial physiological functions, including cardiac activity, autonomic nervous system activity, and physiologic stress. Previous studies in our lab have demonstrated that HRV in female college-age students expressing a BI temperament is significantly lower than in NBI individuals while breathing room air through a two-way non-rebreathing valve. These findings suggested that the parasympathetic nervous system is partially inhibited at rest in BI females; however, it is unknown if the parasympathetic nervous system in these individuals is inhibited prior to or after breathing through a breathing valve. Our current study will address this question by measuring HRV in BI and NBI individuals while breathing room air for 15 minutes without a breathing valve and for 10 minutes with a two-way breathing valve. Raw electrocardiogram signals will be collected throughout the study protocol and will be used to calculate HRV, which will be measured using a BIOPAC data acquisition system during the experiment. BI individuals will be identified through a series of self-reported questionnaires. Our preliminary results indicate that BI individuals have a lower HRV and are stressed throughout the duration of the study. Thank you to Carthage College's Biology and Neuroscience Department for allowing this research project to be conducted. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Cybernetic Proportional System for a Hydraulic Cylinder Drive Using Proportional Seat-Type Valves

Hydraulic cylinders are well known as cheap and robust actuators for moving heavy loads, especially in harsh environments. For this reason, they are often used in construction machines such as excavators. Basically, the hydraulic cylinders are controlled by four-way proportional spool valves, resulting in poor energy efficiency due to resistance control. Furthermore, because all valve edges are located at the same spool, common proportional valves suffer from limited flexibility with regard to different loads. Independent metering (IM) is a well-known strategy for making proportional hydraulic drives more efficient and more flexible because each port of the actuator can be connected individually to pressure or tank by independent two-way proportional valves. In this paper, the IM concept is realized as an open-loop control for a hydraulic cylinder drive, which, in combination with a human operator, constitutes a so-called cybernetic proportional system (CPS). The piston velocity commanded by the operator is controlled by the compensation of the static characteristics of the proportional seat-type valves. Basic simulations show the benefits and also the problems of open-loop independent metering. Furthermore, measurements on one actuator of a real excavator regarding controllability and energy consumption are presented.

Research on the Analysis of Wear Mechanism and Improvement of the Two-way Limit Valve

Aiming at the pollution fault of aircraft hydraulic system caused by the abnormal wear of the two-way limit valve, the method combining theoretical analysis and numerical simulation is used for fault location analysis based on the structural characteristics of the two-way limit valve, and the effect of the main affecting factors, such as the fitting size between parts and the position deviation of the filter holes, on the wear is studied. The results show that the wear of the two-way limit valve is mainly caused by axial assembly gap inside the product, and assembly gap greater than 0.019mm will cause abnormal wear. To solve the problem, it is suggested that no axial assembly gap will be controlled for subsequent product assembly. The two-way limit valve after 100 times of bidirectional alternating pressure supply test has normal performance and no wear phenomenon occurs.

Fast on-off jet control of aerosol jet printing (AJP) using internal rotary valve

Aerosol jet printing (AJP) has been used in additive manufacturing sectors because it has advantages over conventional printing due to its capability of micro-pattern printing on various surfaces including a non-flat (3D) substrate with higher aspect ratio. Since the aerosol systems rely on continuous jet stream, one of the key issues is how to control the on-off of the jets to obtain desired patterns. An external shuttering system outside the nozzle was used to block the jet on non-printing regions. However, there are some downsides, for example, non-optimal stand-off distance due to mechanical interference, unwanted accumulation of the ink on the shutter, and possible mechanical interference when printing on curved surface or surfaces with protrusions. The purpose of this study is to develop AJP system with an internal rotary valve to eliminate the problems of the external shutter. The proposed internal two-way rotary valve can select the jet direction for printing or diverting the jet stream to the air. However, there was jetting delay because it takes time to stabilize the internal pressure. This delay results in non-uniform printing especially when resuming printing from off. In this study, we investigate the pressure behaviors of the flow cell under internal shutter on-off conditions and proposed a new flow rate control method capable of fast on-off control for uniform printing.

Segmented Flow Strategies for Integrating Liquid Chromatography-Mass Spectrometry with Nuclear Magnetic Resonance for Lipidomics.

Building an accurate lipid inventory relies on coordinated information from orthogonal analytical capabilities. Integrating the familiar workflow of liquid chromatography (LC), high-resolution mass spectrometry (HRMS), and tandem mass spectrometry (MS/MS) with proton nuclear magnetic resonance spectroscopy (1H NMR) would be ideal for building that inventory. For absolute lipid structural elucidation, LC-HRMS/MS can provide lower-level structural information with superior sensitivity, while 1H NMR can provide invaluable higher-order structural information for the disambiguation of isomers with absolute chemical specificity. Digitization of the LC eluent followed by splitting the microfractions into two flow paths in a defined ratio for HRMS/MS and NMR would be the ideal strategy to permit correlation of the MS and NMR data as a function of chromatographic retention time. Here, we report an active segmentation platform to transform analytical flow rate LC eluent into parallel microliter segmented flow queues for high confidence correlation of the MS, MS/MS, and NMR data. The practical details in implementing this strategy to achieve an integrated LC-MS-NMR platform are presented, including the development of an active segmentation technology using a four-port two-way valve to transform the LC eluent into parallel segmented flows for online MS analysis followed by offline segment-specific 1H NMR and optimization of the detector response toward segmented flow. To demonstrate the practicality of this novel platform, it was tested using lipid mixture samples.

Pressure Signal-Based Analysis of Anomalies in Switching Behavior of a Two-Way Directional Control Valve

Abstract Solenoid operated direction control valves, responsible for regulating the flow of fluid in hydraulic circuit highly relies on the control current for their actuation. The control currents supplied to the solenoid generate the electromagnetic force required for switching of valves by mechanical movement of spools inside. The deterioration in control current leads to the degradation in electromagnetic force and thus the spool takes longer to initiate as well as terminate the switching phenomenon. This delay or lag potentially causes the pressure, flow and power fluctuation, and unintended impacts on the system. This article presents a comparative analysis of detecting these anomalies by acquiring pressure signals across the valve using extreme gradient boosting (XGBoost) and one-dimensional convolution neural network (CNN). Four handcrafted statistical features and four fractal dimensions train XGBoost whereas 1D CNN with six hidden layers utilizes the raw signal of net pressure change across the valve. XGBoost predicts the switching behavior at an accuracy of 99.68%, and 1D CNN performs at its maximum possible accuracy (100%). The very narrow gap signifies the nearly equal significance of both of these different category classifiers. As XGBoost cannot handle the raw signals, the pre-processing increases the time consumption while 1D CNN does not require deep architecture and efficiently maps the complexity of the hydraulic system using pressure signals.

529 PERSPECTIVES ON CARDIAC OUTPUT EVALUATION IN PULMONARY HYPERTENSION PATIENTS UNDERGOING RIGHT HEART CATHETERIZATION

Abstract Background and aim Right heart catheterization (RHC) is the gold standard for the diagnosing and classifying pulmonary hypertension (PH). Cardiac output (CO) and the derived cardiac index (CI) are cornerstones of the hemodynamic evalution allowing pulmonary vascular resistance (PVR) calculation and risk stratification. According to the current European Guidelines, CO should be assessed by the direct Fick method or thermodilution (TD). The indirect Fick (IF) method based on theorically estimated values for VO2, is deemed acceptable bul lacks reliability. Of note, data from the literature on a direct comparison among these three methods used for CO measurement are poor. The objective of our study is to compare CO evaluation by the DF method (DFCO) with CO assessed by IF (IFCO) and TD (TDCO). Secondly, we aimed at assessing the impact of CO estimation by different methods on PVR measurement and therefore on PH hemodynamic classification. This might translate into relevant diagnostic, prognostic and therapeutic implications. Methods 27 patients underwent RHC. Breath-by breath VO2 was measured through a Rudolph mask connected with a two-way respiratory valve to a metabolic cart and averaged over the course of 12 to 15 minutes. DFCO was calculated using the following formula: VO2 (ml/min)/(arteriovenous oxygen content difference×10). For IFCO, the same formula was used with VO2 computed by the Dehmer and the LaFarge-Miettinen formulas. TDCO was obtained through the injection of 10 ml of cold saline solution (0-4°C), in the right atrium and by measuring the temperature variation in the pulmonary artery. Results RHC revealed PH in 23 patients (85%) Average VO2 by Dehmer formula differed significantly from direct measurement (228.9 ± 27.9 ml/min and 204.4 ± 43.6 ml/min respectively; P = 0.017). By using LaFarge formula, mean estimated VO2 differed from direct measurement without reaching statistical significance (185.3 ± 31.9 ml/min and 204.4 ± 43.6 ml/min respectively, P= 0.072). Average CO values did not differ significantly from each other (DFCO 4.2 ± 1.5 L/min; IFCO 4.7 ± 1.3 L/min; TDCO 4.6 ± 1.2 L/min; P=NS for all pairwise comparisons) and showed significant Pearson's correlation. Out of 27 cases, TDCO differed for more (± 0.5 L/min) than 10% as compared to DFCO in 17 (63%). IFCO differed consistently from DFCO in 12 (44%) and IFCO from TDCO in 17 (63%). Despite discrepancies among different CO measurement methods, Cohen's kappa coefficient showed good agreement between the three methods in high PVR (≥3 WU) estimation (IF vs DF 0.79; TD vs DF 0.83 and IF vs TD 0.92 respectively). Conclusions Our results indicate consistent discrepancies among different approaches for VO2 and CO measurement, however this did not impact over PVR assessment and therefore in PH classification. Probably, this is due to the small sample size and the low number of patients (8 of 27) with values around the pathological cut-off for PVR (3 WU). Further studies are needed to better investigate the magnitude of CO measurement discrepancies among different methods on PVR calculation and hemodynamic classification.

Experimental investigation on the performances of a valve-based and on-demand droplet generator producing droplets in a wide size range

Many aspects of our daily lives are affected by the generation of water droplets, and it is important to controllably produce droplets with a wide size range in various applications. In this paper, we describe an on-demand droplet generating system based on a high-speed two-way solenoid valve. A nozzle made of stainless steel tubing is fit into one port of the valve, and the other port is connected to the fluid reservoir by which the pressure can be controlled via a pressure regulator. When the liquid is pressurized and the valve is opened with a short pulse voltage, trace amounts of liquid will be ejected from the nozzle to form a droplet. Droplet generation is captured using a high-speed camera to measure the dimension and velocity and to evaluate the performances of the generator, such as repeatability and stability. We demonstrate the influences of applied pressure and pulse width of driving voltage on droplet generation. It is shown that the droplet generator is capable of producing droplets in a wide size range for a given nozzle (e.g., about 0.7–2.2 mm for a 1.0 mm diameter nozzle). A single droplet is stably generated at Z = 268.1, obviously higher than the published data and the Weber number of a fluid jet (Wej) ranging from 2.1 to 5.6. The droplet generator presented here will be useful for research related to large droplets, such as freezing rain in atmospheric science and supercooled large drops in aircraft icing.

A comfort performance improved anti-pitch hydraulically interconnected suspension system with switchable dual accumulators

This paper introduces a novel switchable dual accumulators hydraulically interconnected suspension (SDAHIS) system. The proposed SDAHIS system can improve the ride comfort and anti-pitch performances simultaneously compared with the existing anti-pitch hydraulically interconnected suspension (HIS) system. The SDAHIS system uses a two-way valve for accumulators switching. The developed SDAHIS system achieve the function by controlling the connection of the two switchable accumulators. To comprehensively study the proposed system, the SDAHIS system model and the seven-DOF vehicle model are established. The model of the SDAHIS system is validated by the bench test. The simulation results of the full vehicle with the proposed SDAHIS system show that the anti-pitch and ride comfort performances are simultaneously improved. This research further exploits the potential of the HIS system which can help to better design the suspension system.

A Classical Physics Approach for Space Expansion: The Hubble Drift

Accelerating expansion of metric space AEMS is investigated with classical Newtonian mechanics. Relying on earlier positions, the results are analyzed to reveal what could be a new understanding of the theoretical framework of the subject. Notably, it is shown that space is physical; it comprises aggregated waveforms of the chemical elements and shares identical quantization, periodicity and mass-evolution with matter. Three plausible methods are identified for classical investigation of the Hubble effect, all three give same result, Ho= 49.5 km s-1Mpc. AEMS results from coupling of light’s 36.9o tangential component (vr=0.75rω) to periodic space, i.e., a component of the vacuum field’s e-m radiation couples to logarithmically decreasing distance scales, vr(E)/drE, to create an acceleration relative to space not time. Multiplicity of the Hubble constant aHo is traceable to corresponding multiplicity of universes nested within our universe. Mass ejection from a cosmic quantum envelope is the cosmic equivalence of radioactivity, it signals ageing and eventual disappearance of the host periodic envelope from visibility. Reality is an imperturbable (ideal) Steady-State, observations thought to invalidate this view are hugely misinterpreted, an explosion in or of spacetime marking the beginning of time could not conceivably sustain, over the aeons, an accelerating expansion of metric space; furthermore, the cosmic microwave background is the zero-point energy or vacuum radiation. The active galactic nucleus or black hole is not a singularity, it is a two-way valve that facilitates circulation of mass-energy matrices across the four phases or ref. frames of reality. There is no new creation of space or matter, only continuous recycling in line with NASA’s recent observation.

Modular Approach for Modelling Warming up Process in Water Installations with Flow-Regulating Elements

The paper presents a new method for modelling the warming up process of a water system with elements regulating the flow in a stochastic manner. The paper presents the basic equations describing the work of typical elements which the water installation is composed of. In the proposed method, a new computational algorithm was used in the form of an iterative procedure enabling the use of boundary conditions that can be stochastically modified during the warming-up process. A typical situation, when such a modification is processed, is the regulation of the medium flow through two-way or three-way valves or applying additional heat source. Moreover, the presented method does not require the transformation of the differential equations, describing the operation of individual elements, into a linear form, which significantly facilitates analytical work and makes it more flexible. The example of analysis of the operation of water installation used for controlling temperature of the process gases in a chemical installation shows the functionality and flexibility of the method. The adopted calculation schematics enable changing the direction of the heat flow while the heat exchanger is in operation. Additionally, the sequence of calculation processed in modules describing operation of installation elements is elective (there is no situation that output parameters from one element are used as input parameters for other element in the same calculation step).

Breath Analysis of Drivers for Monitoring Their Conditions on Driving Simulator

In this study, we investigated the correlation between the condition of drivers and their expiration using a spirometer and a volatile organic compound (VOC) gas sensor on a driving simulator. Twenty-four participants with normal or corrected-to-normal vision (11 males and 13 females; age range = 19−58 years, mean age = 39.3 years) were enrolled in this study. All participants were licensed drivers who reported driving more than one day per week and never participated in any lectures for motorsports. They were equipped with air-seal masks and transducers of the spirometer (Minato Medical Science AE-310S). The spirometer measured flow rate, oxygen and carbon dioxide concentrations for output to several parameters, such as tidal volume, respiration rate, oxygen consumption, carbon dioxide excretion, end tidal oxygen and carbo dioxide etc. The masks connected to a two-way valve for dividing between inhaled and exhaled breaths (Hans Rudolph series 2600) and a gas sensor chamber for a homemade gas sensor of Pt, Pd, and Au-loaded SnO2. Resistance signal of the gas sensor affected by concentrations of volatile organic compounds (VOCs), so that the gas sensor can monitor to fluctuation of VOCs in exhaled breath. They drove a fixed-base driving simulator (Mitsubishi Precision), which had an automatic transmission system and right-hand-drive and consisted of a cockpit with a steering wheel, an accelerator pedal, a brake pedal, a side brake lever, and a shift lever, as well as a liquid crystal monitor (70-inch) and speakers (for simulated noise of engine and tires). They drove in the overtaking lane at 90−100 km/h on four different courses of varying difficulty for approximately 5 minutes each. All courses include straight roads, right-curves, and left-curves. All curves were shallow (1000R) and sharp (200R), and the frequency of curves were infrequent and frequent (0.8 and 0.2 km straight road between curves). The mean and standard deviation (SD) of all breath parameters from them were calculated during the cruising section of the courses. After driving each course, they assessed the “enjoyment” and “difficulty” of the course on a scale of one to seven. The mean and SD of all parameters were analyzed using box-and-whisker plots and two-way analysis of variance (ANOVA). There was no significant difference in the correlation between the questionnaire result of “difficulty” and each parameter of the spirometer and gas sensor. Also, the mean of all breath parameter shows no significant difference to the questionnaire result of “difficulty” and “enjoyment”. By contrast, the low (1, 2, and 3 points) and high (5, 6, and 7 points) assessment groups of "enjoyment" showed large and small SDs of all parameters from the spirometer and the gas sensor, respectively. Specifically, in the highest course difficulty (C4), there was a clear tendency between the SDs and the assessment of “enjoyment”. The box-and whisker plots show the tendency. Two-way ANOVA shows p-values classified according to the assessment, courses and, their interaction. The p-values, used in statistical study, mean the significant difference of the parameter. The parameter possesses the significant differences when the p-values of the parameter is less than 0.05. On the two-way ANOVA between “enjoyment” and courses of SDs from all parameters, the “enjoyment” and the interaction showed high significant differences with less than 0.01 of p-values. No significant differences were observed from the courses, so that there is no dependency of the running course and only the assessment of “enjoyment” was effective. Moreover, no differences were found in comparison with the parameters from the spirometer and the gas sensor so that the condition of the driver could be evaluated objectively even when only one parameter was monitored.Ref. T. Itoh, T. Sato, T. Akamatsu, W. Shin, J. Breath Res. 2019, 14, 016003. Figure 1

Comparison of physical properties of voluntary coughing, huffing and swallowing in healthy subjects.

Coughing, huffing and swallowing protect the airway from aspiration. This study was conducted to compare the physical properties of voluntary coughing, huffing and swallowing in healthy subjects. Ten healthy men were asked to huff, cough and swallow repeatedly. Electromyograms (EMGs) were recorded from the left side of the external oblique (EO), sternocleidomastoid, suprahyoid (SH) and thyrohyoid muscles. Airflow was recorded using a face mask with two-way non-rebreathing valves. The expiratory velocity of huffing and coughing and the SH EMG of all actions presented high intraclass correlation coefficients (> 0.8). The inspiratory and expiratory velocities did not differ significantly between coughing and huffing. The expiratory acceleration of coughing was significantly higher than that of huffing, whereas the expiratory volume of coughing was significantly smaller than that of huffing. The EO EMG of coughing and huffing were significantly larger than that of swallowing. The EO EMG activity during the expiratory phase was significantly higher than that of the other phases of both coughing and huffing. The SH EMG of coughing and huffing were significantly smaller than that of swallowing. Correlation analysis revealed that the expiratory velocity of coughing was strongly positively correlated with that of huffing. The expiratory volume of huffing was significantly positively correlated with hand grip strength. These results suggest that EO and SH muscle activities during huffing or coughing differ those during swallowing, and huffing and coughing may work similarly in expiratory function.

Effect of modified inlet flow strategy on the segregation phenomenon in pulsed fluidized bed of ultrafine particles: A collapse bed study

Unlike conventional fluidization of micron-sized particles, the hydrodynamics of ultrafine nanopowders is controlled by their agglomerates, which show strong segregation pattern along the bed height. This aspect was carefully investigated in this study by carrying out collapse experiments in a low-frequency pulsed fluidized bed. Unlike previous studies, the inlet flow was modified with the help of four-way valve configuration to eliminate the inlet flow spike. The region-wise collapse dynamics was monitored by recording pressure transients along the height of the fluidized bed while double drainage deaeration strategy, termed modified dual drainage (MDD), was employed. The size of agglomerates in the different bed regions were evaluated and compared with the conventional single drainage (SD) and dual drainage (DD) deaeration configurations using two-way and three-way solenoid valves. The elimination of the flow spike with MDD helped to suppress the size-based segregation of agglomerates, thereby resulting in faster and smoother bed collapse.

Batch chromatography with recycle lag. II—Physical realization and experimental validation

This is the second of a two-part study in which we explore the concept of batch chromatography with recycle lag, concluding with the design, construction, and experimental validation of a prototype—an eluate recycling device (ERD)—that embodies the physical realization of this concept. The ERD implements an approximate “first in, first out” method of organizing and manipulating the to-be-recycled fractions of eluate collected from the chromatography column, where the oldest (first) amount fluid, or ‘head’ of the fraction, is the first to exit and be recycled back to the column. Moreover, the apparatus is simple to set up in particular in view of large-scale applications. Here we detail the construction of the ERD and assembly of a setup to interconnect the ERD and a chromatography column. Through the coordinated operation of two-way valves and two-position six-port switching valves it is possible to implement a diverse set of configurations or operating modes interconnecting the chromatography column and the ERD. The setup is validated experimentally with success using the separation of a nucleoside mixture by reversed phase chromatography as a model problem. It is also shown that by redesigning the fluid distributor using 3D printing technology the ERD performance can be improved.

Breath Analysis of Drivers for Monitoring Their Conditions on Driving Simulator

In this study, we investigated the correlation between the condition of drivers and their expiration using a spirometer and a volatile organic compound (VOC) gas sensor on a driving simulator. Twenty-four participants with normal or corrected-to-normal vision (11 males and 13 females; age range = 19−58 years, mean age = 39.3 years) were enrolled in this study. All participants were licensed drivers who reported driving more than one day per week and never participated in any lectures for motorsports. They were equipped with air-seal masks and transducers of the spirometer (Minato Medical Science AE-310S). The spirometer measured flow rate, oxygen and carbon dioxide concentrations for output to several parameters, such as tidal volume, respiration rate, oxygen consumption, carbon dioxide excretion, end tidal oxygen and carbo dioxide etc. The masks connected to a two-way valve for dividing between inhaled and exhaled breaths (Hans Rudolph series 2600) and a gas sensor chamber for a homemade gas sensor of Pt, Pd, and Au-loaded SnO2. Resistance signal of the gas sensor affected by concentrations of volatile organic compounds (VOCs), so that the gas sensor can monitor to fluctuation of VOCs in exhaled breath. They drove a fixed-base driving simulator (Mitsubishi Precision), which had an automatic transmission system and right-hand-drive and consisted of a cockpit with a steering wheel, an accelerator pedal, a brake pedal, a side brake lever, and a shift lever, as well as a liquid crystal monitor (70-inch) and speakers (for simulated noise of engine and tires). They drove in the overtaking lane at 90−100 km/h on four different courses of varying difficulty for approximately 5 minutes each. All courses include straight roads, right-curves, and left-curves. All curves were shallow (1000R) and sharp (200R), and the frequency of curves were infrequent and frequent (0.8 and 0.2 km straight road between curves). The mean and standard deviation (SD) of all breath parameters from them were calculated during the cruising section of the courses. After driving each course, they assessed the “enjoyment” and “difficulty” of the course on a scale of one to seven. The mean and SD of all parameters were analyzed using box-and-whisker plots and two-way analysis of variance (ANOVA). There was no significant difference in the correlation between the questionnaire result of “difficulty” and each parameter of the spirometer and gas sensor. Also, the mean of all breath parameter shows no significant difference to the questionnaire result of “difficulty” and “enjoyment”. By contrast, the low (1, 2, and 3 points) and high (5, 6, and 7 points) assessment groups of "enjoyment" showed large and small SDs of all parameters from the spirometer and the gas sensor, respectively. Specifically, in the highest course difficulty (C4), there was a clear tendency between the SDs and the assessment of “enjoyment”. The box-and whisker plots show the tendency. Two-way ANOVA shows p-values classified according to the assessment, courses and, their interaction. The p-values, used in statistical study, mean the significant difference of the parameter. The parameter possesses the significant differences when the p-values of the parameter is less than 0.05. On the two-way ANOVA between “enjoyment” and courses of SDs from all parameters, the “enjoyment” and the interaction showed high significant differences with less than 0.01 of p-values. No significant differences were observed from the courses, so that there is no dependency of the running course and only the assessment of “enjoyment” was effective. Moreover, no differences were found in comparison with the parameters from the spirometer and the gas sensor so that the condition of the driver could be evaluated objectively even when only one parameter was monitored.Fig. (a) The driving simulator used in this study, (b) Air-seal mask with transducer and two-way valve.Ref. T. Itoh, T. Sato, T. Akamatsu, W. Shin, J. Breath Res. 2020, 14, 016003. Figure 1

Identification of Particles in Exhaled Air Using Mass Spectrometry

Bronchiolitis obliterans syndrome (BOS) as a form of chronic lung allograft dysfunction is a limiting factor to the survival of lung transplant recipients. Detection and monitoring of chronic rejection is hampered by a lack of clinically available markers. Particles in exhaled air (PExA) is proposed as a noninvasive means of potentially identifying and observing BOS patients. This pilot study aims to capture the range of exhaled particles expected in human samples and identify possible candidate markers. The PExA device collects exhaled air using a two-way valve that allows subjects to inhale filtered air and exhale air into a reservoir from which an optical particle counter counts and sizes entering particles. Particles are collected according to their inertia and those above a threshold impact onto a plate, collecting onto a membrane of polytetrafluoroethylene. Total accumulated mass can be measured by the PExA device. Samples were obtained from two healthy subjects (1 combined 600 ng sample and 200 ng from each) and from five patients with lung pathology (1 grouped sample of 600 ng from three patients and 200 ng samples from two unique patients). The samples were analyzed via liquid chromatography-mass spectrometry on an Orbitrap Fusion Lumos mass spectrometer coupled to an easy-nLC1200 liquid chromatography system. The fifty most abundant proteins identified by mass spectrometry represented a breadth of biological function and a variety of localizations. Ten could be traced to immunological system processes and included a number of immunoglobulin constant regions. Sixteen of these most abundant proteins could be found in the extracellular region. A number are components of the plasma, including serotransferrin and annexin proteins. Fifteen proteins were found in greater abundance in the healthy subjects compared to patients while two (haptoglobin and gasdermin-A) were notable for a lower abundance in the patients. The PExA device presents as a novel method for non-invasive analysis of lung transplant patients with the potential to monitor developing chronic rejection. This pilot study characterizes the range of proteins identified from samples across subjects and serves as a basis for the exploration of markers in chronic rejection patients. This work establishes a method for the ongoing effort to use PExA to identify and monitor BOS in lung transplant recipients.

Energy optimization of pneumatic actuating systems using expansion energy and exhaust recycling

As an important power source in industrial applications, compressed air makes up an increasingly large proportion of total industrial energy consumption. Due to the compression and leakage of air, however, pneumatic actuating systems have suffered from a low utilization of compressed air. Moreover, for a traditional pneumatic circuit, a three-position five-way valve is used to control the air inlet and exhaust with a single pressure, also causing low efficiency. This study proposes a novel bridge circuit to realize energy savings through utilizing compressed air expansion energy and exhaust energy. The circuit consisted of five two-position two-way switch valves. The open-and-close sequence of these valves was used to control the motions of a cylinder piston. This circuit could realize system energy conservation by less air intake and waste air reuse, while simultaneously ensuring that the piston reached the end of its stroke with stability. In order to optimize air consumption, a nonlinear dynamic system optimization model was built based on the idea of dynamic optimization, and the pressure and flow of the pneumatic system and the dynamic equation were considered as constraint conditions. Optimization of the open-and-close sequence of the five switch valves in the bridge circuit was conducted using orthogonal collocation on finite elements and the interior point method. Lastly, a bridge actuator test platform was built to test the stability and energy efficiency of the proposed pneumatic circuit based on the open-and-close sequence obtained through the optimization algorithm with different air supply pressures and workloads. Compared with the traditional circuit, the proposed circuit yielded energy savings of 55–87%, and the impact acceleration at the end point is smaller than that at the end point, with only −0.01–0.02 m/s. These results suggested that the circuit is important for enhancing the utilization of compressed air.

HPLC-assisted automated oligosaccharide synthesis: the implementation of the two-way split valve as a mode of complete automation.

Reported herein is the development of a user-friendly platform for simple and transformative automation based on standard HPLC equipment. We showcase how the improved platform works in application to the completely automated, a "press of the button," synthesis of various glycan sequences.