Real-time Measurement Method Research Articles

A new method to quantify penile erection hardness: real-time ultrasonic shear wave elastography.

BackgroundAn important indicator of penile erectile function is erection hardness (EH), which is currently evaluated by the semi-quantitative erectile hardness score (EHS). EH increases continuously during the course of an erection, so although it is statistically a continuous variable, the EHS is a grade variable. We propose a new method for real-time quantitative measurement of penile EH using ultrasonic shear wave elastography (SWE).MethodsThe study group comprised 40 patients with erectile dysfunction (ED) and 20 normal controls who all underwent real-time SWE to measure tissue stiffness (Young’s modulus, YM) of the penile corpus cavernosum and tunica albuginea during erection, at rest and at different EH grades induced by intracavernosal injection (ICI) of prostaglandin. The examiner gently placed the high frequency probe on the ventral penis and got the two-dimensional longitudinal US image of penis, then switched to SWE mode, the appropriate region of interest (ROI) was selected, then a 3–5 mm circle (“Q-box”) was automatically set to by machine to measure the SWE of the corpus cavernosum and tunica albuginea on the left side.ResultsIn both the ED patients and normal controls, YM slightly decreased in the corpus cavernosum during erection but the stiffness of tunica albuginea increased significantly with increasing EH (resting: 21.66±4.21 kPa, grades 1–4: 32.61±4.27, 54.86±8.69, 128.02±20.66, and 223.23±23.61 kPa, respectively). Because EH grades 1 and 2 clinically predicted failure to complete sexual intercourse, and EH grades 3 and 4 predicted ability, the cutoff point for the YM of the tunica albuginea to evaluate whether sexual intercourse could be completed was 81.60 kPa.ConclusionsOur data demonstrated that tunica albuginea stiffness, not corpus cavernosum stiffness, provided a good clinical imaging index indicator for evaluating penile EH. The tunica albuginea stiffness changed continuously during penile erection, which could be measured quantitatively by SWE. Compared with the EHS, measuring the YM of the penile tunica albuginea using SWE is a new and objective technique for quantitatively assessing EH. Because of its objective and quantifiable characteristics, measuring YM enables more accurate evaluation of the effect on EH of various treatments for ED.

Real-time measurement method of melt pool temperature in the directed energy deposition process

In metal additive manufacturing, the quality of the parts is closely related to the temperature distribution in the melt pool; hence, real-time monitoring of the temperature distribution has become a common method of evaluating printing quality. However, there are difficulties in the temperature measurement of a melt pool related to its small size, high temperature, and rapid melting and cooling. A high-speed measuring optical path for a temperature field using a single camera is designed based on dual-wavelength thermometry herein. A dual-waveband image-matching method with sub-pixel accuracy, and a multi-parameter cooperative optimization and calibration method of proportional coefficient K, λ1, and λ2 are developed. Moreover, it was found that the splitting ratio of a beam splitter is not a constant value, rather, it is a distribution; hence, an accurate calibration method for the splitting ratio distribution of the optical system is developed. An on-line temperature measurement system is developed, and its validation experiment indicates a measuring error of less than 1%. The temperature distribution of the melt pool in the directed energy deposition (DED) process was measured. It was found that the temperature distribution was uneven, and the position of the high-temperature peak region changed with time. The evolution law of profile size and temperature change rates during the formation, development, and cooling process of the melt pool are analyzed. The method developed herein significantly reduces the system development cost, and can realize real-time monitoring of the temperature distribution of the melt pool in DED processing.

Videometric mass flow control: A new method for real-time measurement and feedback control of powder micro-feeding based on image analysis.

The present paper reports the first monitoring and control of ultra-low dose powder feeding using a camera image-based mass flow measurement system. Caffeine was fed via a single-screw microfeeder as a model active pharmaceutical ingredient (API). The mass, mass flow and sizes of the particles were successfully monitored in real-time by the developed videometric system consisting of a high-speed process camera coupled with an image analysis software. The system was also tested in feedback control mode to automatically reach the desired mass flow values by adjusting the feeder speed based on the mass flow measured by the image analysis system. Based on these features, the developed videometric system can serve as a multi-purpose PAT-tool and can provide valuable real-time information about the process which is indispensable for modern continuous pharmaceutical manufacturing.

Real-Time Method of Obtaining Rock Mechanics Parameters Based on the Core Drilling Test

Abstract Accurately obtaining the mechanics parameters of the surrounding rock at an engineering site in real time is a key component of the construction process that is required to determine and adjust the support scheme in a timely manner and thus ensure construction safety. Currently, studies of the real-time measurement methods of the cohesion, c, and internal friction angle, φ, of the surrounding rock at a site are relatively limited, and the digital core drilling test technique provides a new approach for obtaining accurate rock parameters (c and φ) in real time at an underground engineering site. Based on the principle of upper bound analysis, in this article, a relationship model between the core drilling parameters and rock mechanics parameters (CDP-RMP) is established, and the rock core drilling cutting strength is obtained. An inversion method is proposed to obtain the rock parameters (c and φ). Additionally, by using the multifunctional rock digital drilling test system developed, digital core drilling tests are conducted on rock specimens with different lithologies. The results show that the inversion values for the rock parameters c and φ are essentially consistent with the results of the triaxial test, which verifies the accuracy of the CDP-RMP model and that of the inversion method for the rock parameters c and φ. A real-time method for obtaining rock mechanics parameters based on the digital core drilling test is further established. This method can conveniently obtain accurate mechanical parameters for the surrounding rock onsite in real time and provides a foundation for the timely optimization of the support scheme and the informatization construction of underground engineering.

A novel real-time measurement method for dynamic resistance signal in medium-frequency DC resistance spot welding

Resistance spot welding (RSW) is widely used in auto-body manufacturing, and the weld quality is critical to ensure the safety and reliability of an automobile structure. The dynamic resistance (DR) signal is one of the most frequently applied process signals for real-time quality monitoring and control of RSW. However, the accuracy of DR measurement is highly affected by the inductive component of the secondary voltage signal. In a medium-frequency direct-current (MFDC) RSW system, it is proven that traditional DR measurement methods such as the root mean square (RMS) method and average method fail to eliminate the interference of inductance, and barely meet the monitoring requirements. Therefore, a novel real-time DR measurement method based on a forgetting-factor recursive least square algorithm is proposed and tested under simulated and experimental conditions in this paper. Sensitivity analysis is performed to optimize the forgetting factor, which is proven to be the critical parameter of the novel method to balance the convergence speed and oscillation amplitude. With the optimized forgetting factor, the error analysis and comparative study are conducted under different welding modes. The results show that the inductive noise can be effectively eliminated by the new method. The measurement error of the proposed method is limited within ±6 µΩ at a 99.73% confidence level (±3σ) at both constant and time-varying current modes. This study can pave the way for real-time monitoring and control for an MFDC RSW system.

Substrate binding in the processive cellulase Cel7A: Transition state of complexation and roles of conserved tryptophan residues

Cellobiohydrolases effectively degrade cellulose and are of biotechnological interest because they can convert lignocellulosic biomass to fermentable sugars. Here, we implemented a fluorescence-based method for real-time measurements of complexation and decomplexation of the processive cellulase Cel7A and its insoluble substrate, cellulose. The method enabled detailed kinetic and thermodynamic analyses of ligand binding in a heterogeneous system. We studied WT Cel7A and several variants in which one or two of four highly conserved Trp residues in the binding tunnel had been replaced with Ala. WT Cel7A had on/off-rate constants of 1 × 105 m-1 s-1 and 5 × 10-3 s-1, respectively, reflecting the slow dynamics of a solid, polymeric ligand. Especially the off-rate constant was many orders of magnitude lower than typical values for small, soluble ligands. Binding rate and strength both were typically lower for the Trp variants, but effects of the substitutions were moderate and sometimes negligible. Hence, we propose that lowering the activation barrier for complexation is not a major driving force for the high conservation of the Trp residues. Using so-called Φ-factor analysis, we analyzed the kinetic and thermodynamic results for the variants. The results of this analysis suggested a transition state for complexation and decomplexation in which the reducing end of the ligand is close to the tunnel entrance (near Trp-40), whereas the rest of the binding tunnel is empty. We propose that this structure defines the highest free-energy barrier of the overall catalytic cycle and hence governs the turnover rate of this industrially important enzyme.

Study on a digital drilling test–based rock uniaxial compressive strength measurement method

Real-time and accurate measurement of the uniaxial compressive strength of rock on-site is the foundation of the design optimization and digital construction of the support structure in an underground project. Currently, effective methods to obtain the rock uniaxial compressive strength Rc in real-time on-site are scarce. Digital drilling test technology provides a new opportunity to solve this problem; however, the lack of a universal relational model for the drilling parameters versus Rc constrains further development of this technology. In this study, based on developed PDC bit for probing, the Sc parameters of rock cutting strength are proposed, and the relational equation between Sc and drilling parameters is deduced. Using an in-house-developed rock drilling test system, laboratory digital drilling tests for sandstone and mortar specimens with various strengths are performed. Based on the test results, a relational equation between Rc and Sc is developed. Subsequently, a relational model for drilling parameters versus Rc (the DP-Rc model) is developed, and its effectiveness is verified. The results show that the average difference in the uniaxial compressive strength predicted by the DP-Rc model versus the Rc measured in the uniaxial test is less than 10%, which proves the effectiveness of this model. On this basis, we propose a digital drilling test–based rock uniaxial compressive strength real-time measurement method that provides the foundation for the real-time and accurate measurement of the uniaxial compressive strength of the surrounding rock in underground projects.

基于光梳的实时高分辨相位测量方法理论分析

基于光梳的实时高分辨相位测量方法理论分析

Assessment of the carotid artery Doppler flow time in patients with acute upper gastrointestinal bleeding.

INTRODUCTION:Because of the subjectivity and ambiguity of the noninvasive measurements and limited use of invasive ones, there is an impending need for a real-time, fast, inexpensive, and reproducible noninvasive measurement method in acute upper gastrointestinal (GI) bleeding with active bleeding in emergency services.AIMS:In this study, we aimed to evaluate the effect of bedside carotid artery flow time (CFT) measurement before and after the passive leg raising (PLR) maneuver on the determination of active bleeding in patients admitted to the emergency department (ED) with upper GI bleeding.MATERIALS AND METHODS:This prospective case–control study was conducted in the ED of a training and research hospital with upper GI bleeding. Patients were placed in the supine position to perform bedside carotid Doppler ultrasonography before starting treatment. CFT, corrected CFT (CFTc), and carotid artery Doppler flow velocity were measured. After then performed PLR, the same parameters were measured again.RESULTS:A total of 94 patients, including 50 patients with GI bleeding and 44 healthy volunteers as control group were included in the study. CFT and CFTc were shorter in the patient group than the control group (P < 0.001, P = 0.004, respectively). After PLR, there were statistically significant differences in change in the CFT (ΔCFT) and change in the corrected CFT (ΔCFTc) between the groups (P = 0.001, P < 0.001). There were also statistically significant differences in ΔCFT and ΔCFT between the patients with active bleeding and the nonbleeding ones (P = 0.01, P = 0.005, respectively). Area under curve to detect active bleeding for ΔCFT and ΔCFTc were calculated as 0.801 (95% confidence interval [CI]: 0.65–0.95) and 0.778 (95% CI: 0.63–0.91), respectively.CONCLUSION:The corrected carotid Doppler flow time measurements in patients with GI bleeding at the time of presenting to the emergency department can be helpful to interpret the active bleeding.

Magnetic resonance measurements of cellular and sub-cellular membrane structures in live and fixed neural tissue.

We develop magnetic resonance (MR) methods for real-time measurement of tissue microstructure and membrane permeability of live and fixed excised neonatal mouse spinal cords. Diffusion and exchange MR measurements are performed using the strong static gradient produced by a single-sided permanent magnet. Using tissue delipidation methods, we show that water diffusion is restricted solely by lipid membranes. Most of the diffusion signal can be assigned to water in tissue which is far from membranes. The remaining 25% can be assigned to water restricted on length scales of roughly a micron or less, near or within membrane structures at the cellular, organelle, and vesicle levels. Diffusion exchange spectroscopy measures water exchanging between membrane structures and free environments at 100 s-1.

Preparation of zinc porphyrin nanoparticles and application in monitoring the ethanol content during the solid-state fermentation of Zhenjiang Aromatic vinegar

This work presents a real-time ethanol content measurement method during the solid-state fermentation of “Zhenjiang” Aromatic vinegar. 5, 10, 15, 20-Tetraphenyl-21H, 23H-porphine zinc (ZnTPP) which was sensitive to ethanol was employed to capture VOC from semi-solid state vinegar during fermentation. Various self-assembled nanostructures of ZnTPP based was be synthesized, while the effect of aging time and the pH on the morphology of nanoporphyrin has been studied. The result of self-assembled was characrized by change of UV spectra. After self-assembled, the colorimetric signal of ethanol VOC was, significantly enhanced. Furthermore, colorimetric sensor array made up of four colorimetric dyes with porphyrin and nanostructure porphyrin were used for VOC detection during vinegar fermentation. Meanwhile, when it is combined with back-propagation artificial neural network (BP-ANN), volatile gas messages of vinegar substrate present an high relevance with alcoholic strength measured by Gas chromatography and mass spectrometry (GC–MS). Therefore, the colorimetric sensor array based on ZnTPP nanoparticles could be well used in monitoring the ethanol content during the solid-state fermentation.

ALL ROADS LEAD TO DOPAMINE: EXPLORING THE GENETIC LINK BETWEEN ADHD, OBESITY MEASURES AND BRAIN VOLUMES

For the great potential Fe-Mn-Si shape memory alloy (Fe-SMA), which is less expensive compared with the Ni-Ti system, tension-compression asymmetry in stress-strain curve is reported in the past. It is considered that the difference in thermomechanical and stress-induced martensitic transformation behavior may also be observed under different loading modes in Fe-SMA. In this paper, an experimental investigation under compression is conducted to make clear the rate dependency of thermomechanical and phase transformation behavior in Fe-SMA at the previous study focusing on the behavior under tension. During both quasi-static and impact compression, the amount of stress-induced ε-martensite can be indirectly evaluated by using a real-time measurement method of an electrical resistance. Furthermore, temperature change which becomes an important aspect of the study on the phase transition is also captured. In addition, after compressive test and heating, it is attempted to investigate the rate dependency of volume fraction of stress-induced ε-martensite and shape recovery strain. Finally, the microstructural observation of the samples taken from the specimen is carried out.

Method for real-time measurement of the nonlinear refractive index

In this work, we propose a novel method for continuous real-time measurement of the dynamics of the nonlinear refractive index n2. This is particularly important for characterizing phenomena or materials (such as biological tissues, gases, and other compounds) whose nonlinear behavior or structure varies rapidly with time. The proposed method ingeniously employs two powerful tools: the spectral broadening induced by self-phase modulation and the real-time spectral analysis using the dispersive Fourier transformation. The feasibility of the technique is experimentally demonstrated, achieving high-speed measurements at rates of several megahertz.

Real-Time Image-Based Defect Inspection System of Internal Thread for Nut

The most important components of the internal nut thread inspection process are measuring the pitch and pitch diameter value and comparing these with their respective specifications, as a test nut is considered to be abnormal when its pitch or pitch diameter does not meet specifications. This paper focuses on defects arising when the pitch diameter does not meet its specification. Because conventional contact strategies are not suited to the real-time inspection of internal thread defects, there have been a number of recent attempts to develop noncontact methods for real-time measurement. Some approaches have applied laser triangulation techniques in which reflected light is used to measure the z-axis depth on an object’s surface. Although point lasers have been shown to be highly precise in measuring pitch diameter, the optical architecture involved in these approaches is complicated and, as the laser must be scanned in a pointwise manner to derive cross-sectional measurements, the measurement process is too long to be compatible with real-time defect inspection. In this papere, an image-based method employing a line laser projector was used to develop a real-time image-based nut pitch diameter defect inspection system. The proposed method, which improves upon the conventional, widely used template-matching method for rapid defect detection, was shown to be effective through experimental validation.

International Economic Cooperation，Domestic Economic Stability and the Improvement of Current Account Imbalances

After 2008, the barriers to cross-border flows of production factors such as commodities, capital, and labor have become increasingly apparent. The new round of liberalism has quietly risen, triggering a wave of counter-globalization characterized by anti-free trade and anti-integration”. Some developed countries have attempted to go beyond the constraints of the structural adjustment of the global economy and embark on the so-called priority of interest and self-development”. This, to a certain extent, weakened the synchronization of the world economic cycle and objectively exacerbated the synthetic fallacy” in the global economic development. In the absence of effective international economic rules and regulations, this synthetic fallacy” may cause frictions in trade, finance, and other areas to increase, thereby accelerating current account imbalances.Based on the above facts, this paper regards current account imbalances as the result of the internal and external factors, and combines the changes in the economic globalization process with macroeconomic uncertainty to explore whether the synchronization between China and the world economic cycle has changed. Is there any uncertainty in China’s macro-economy, and how does it affect current account imbalances, accelerating or smoothing? If the synchronization between China and the world economic cycle is reduced and macroeconomic uncertainty is raised, will it accelerate current account imbalances? What is the impact? Firstly, the method of real-time measurement of macroeconomic uncertainty using large-scale mixed macroeconomic data sets is proposed, and the macroeconomic uncertainty index is constructed. It avoids the possibility of directly using the substitution variables such as financial market volatility in the past literature to reflect the possible deviation of macroeconomic uncertainty. Then we use the Markov framework to establish a macroeconomic cycle synchronization index. Finally, the vector autoregressive model with Bayesian variable selection （VAR-BVS） weakens the endogeneity problem caused by missing or mistaken variables, and analyzes the dynamic relationship between the three before and after the global financial crisis. The study examines the possible links between the three.The study finds that: The relationship between the two is similar to a U-shape curve with the synchronization of the world economic cycle as the horizontal axis and current account imbalances growth rate as the vertical axis. Whether before or after the crisis, macroeconomic uncertainty plays an accelerator” role in current account imbalances. In the long term, the increase in macroeconomic uncertainty has an accelerating effect on current account imbalances. In the short term, in addition to the impact of the domestic economic environment, the decline in the synchronization of the world economic cycle will play an important role in accelerating current account imbalances. The reason for the synchronization between China and the world economic cycle, and macroeconomic uncertainty affecting current account imbalances may be due to the international division of labor, factor mobility, and preventive savings motivation. There is structural heterogeneity in the relationship between domestic and foreign economic environment and current account imbalances, which is different from the relationship between trade in goods and trade in services. The findings show that a stable domestic economic environment and a cooperative international economic environment are important conditions to improve current account imbalances.

In Vivo Quantitative Photoacoustic Diagnosis of Gastric and Intestinal Dysfunctions with a Broad pH-Responsive Sensor

Gastrointestinal diseases affect many people in the world and significantly impair life quality and burden the healthcare system. The functional parameters of the gastrointestinal tract such as motility and pH can effectively reflect the changes of gastrointestinal activity in physiological and pathological conditions. Thus, a noninvasive method for real-time and quantitative measurement of gastrointestinal functional parameters in vivo is highly desired. At present, there are many strategies widely used for the diagnosis of gastrointestinal diseases in clinic, including X-ray barium meal examination, ultrasound imaging, radionuclide examination, endoscopy, etc. However, these methods are limited in determining the gastrointestinal status and cannot provide comprehensive quantitative information. Photoacoustic imaging (PAI) is a rapid noninvasive real-time imaging technique in which multiple types of functional and quantitative information can be simultaneously obtained. Unfortunately, very few ratiometric PAI contrast agents have been reported for quantification of gastrointestinal functional parameters in vivo. In this work, a broad, pH-responsive ratiometric sensor based on polyaniline and Au triangular nanoplates was developed. Utilizing the sensor as a contrast agent, PAI served as an all-in-one technique, accurately measuring the gastrointestinal functional parameters in a single test. Notably, this sensor was examined to be ultrasensitive with pH responses as fast as 0.6 s and durability as long as 24 h, and was repeatable and reversible for longitudinal monitoring. The quantitative results demonstrated a significant disorder in motility and decrease in pH for gastric and duodenal ulcers. Collectively, the combination of PAI and this broad pH-responsive sensor might be a promising candidate for quantitative diagnosis of gastrointestinal diseases.

Real-time 3-D shape measurement based on radial spatial carrier phase shifting from circular fringe pattern

In this paper, we propose a method to realize real-time three-dimensional (3-D) measurement with a radial spatial carrier phase shifting algorithm. The circular fringe patterns are continuously projected onto the moving object; the distorted fringe patterns are recorded by CCD. In the 3-D reconstruction process, three patterns consisting of one recorded image and two artificial phase shifting fringe patterns are used to implement phase shifting, where the two artificial patterns are formed by numerically shifting the recorded image along the radial direction. Compared with traditional carrier phase shifting method, the proposed method possesses lower phase error and higher accuracy. The simulations and two experiments are carried out to testify the proposed method. From the experimental results of the static object, we find that the standard deviation of the proposed method is better than that of the traditional one. The dynamic experiment of a moving lampshade shows that the time resolution of our method is the same as the CCD. As a real-time quantitative dynamic measurement method, it can be applied in various fields.

An experimental investigation on rate dependency of thermomechanical and Stress-induced martensitic transformation behavior in Fe-28Mn-6Si-5Cr shape memory alloy under compression

For the great potential Fe-Mn-Si shape memory alloy (Fe-SMA), which is less expensive compared with the Ni-Ti system, tension-compression asymmetry in stress-strain curve is reported in the past. It is considered that the difference in thermomechanical and stress-induced martensitic transformation behavior may also be observed under different loading modes in Fe-SMA. In this paper, an experimental investigation under compression is conducted to make clear the rate dependency of thermomechanical and phase transformation behavior in Fe-SMA at the previous study focusing on the behavior under tension. During both quasi-static and impact compression, the amount of stress-induced ε-martensite can be indirectly evaluated by using a real-time measurement method of an electrical resistance. Furthermore, temperature change which becomes an important aspect of the study on the phase transition is also captured. In addition, after compressive test and heating, it is attempted to investigate the rate dependency of volume fraction of stress-induced ε-martensite and shape recovery strain. Finally, the microstructural observation of the samples taken from the specimen is carried out.

Method for real-time measurement of fluctuations of the ratio of peak power to duration of high-repetition-rate ultrashort pulses

A method is proposed for estimating ratio fluctuations of the peak power to the duration of ultrashort pulses (USPs), based on the measurement of the radiation spectrum nonlinearly broadened in the Kerr medium for only four wavelengths. The method provides a fairly simple measurement processing which can be performed in real time using analogue circuitry even without the digitisation of signals, whereas the operation speed is only limited by the response time of photodetectors and analogue circuits. Numerical studies have shown the possibility of applying the method even for pulses having a substantial asymmetry and containing a significant pedestal. The use of the developed method for analysis of fluctuations of the pulse parameters of a high-power laser system has been experimentally demonstrated, with a short optical fibre section employed for spectrum broadening.

A Novel Test Method for Real-time Magnetic Flux Measurement of Power Transformers

Optimizing magnetic flux distribution in iron cores is very important in the transformer design. It can affect whether the iron cores of transformers are saturated or not in severe con ...