Jet Length Research Articles

Characterization of stabilized water-beam fiber for water jet guided laser

In water jet guided laser processing technology, the stability of the water jet directly affects the processing quality. In order to investigate the flow characteristics of water jets, a numerical model of the flow field inside the water beam fiber is established, and the influence of different jet speeds and nozzle diameters on the formation of a stable water jet beam length with a flat cylindrical nozzle structure is analyzed. Computational fluid dynamics simulations show that a 120 μm diameter cylindrical nozzle structure with a length of 1 mm and no chamfered inlet has a maximum stabilized water jet length of 60 mm at a jet velocity of 70 m/s. The smaller the nozzle diameter, the more prone to water jet turbulence, and increasing the nozzle diameter can increase the stable length of the water jet to a certain extent. Finally, by conducting the water jet stable length experiment with different jet velocities, the maximum stable length of 65 mm is obtained and the accuracy of the simulation is verified, which provided a strong theoretical basis for the subsequent processing experiments.

How does an emulsion drop's viscosity influence its impact on various meshes?

The impact of emulsion drops on a mesh is studied. These drops find applications in various fields, e.g., agricultural sprays, where the drop passes through a mesh for atomization. Both penetration (full or partial) and lateral spreading are observed in most cases. The maximum spread's variation with Weber number (We) shows liquid independence for drops impacting a given mesh. The variations can be concluded into one. However, when both lateral spread and penetration are concerned, the emulsion drop with the highest water content tested stands out as different. It shows dissimilar characteristics due to its higher viscosity. The drop's lateral spread Reynolds number is lower than the others, indicating a significant dependence on the liquid viscosity. Rising viscosity resists the lateral inertia. Surface tension (ST) and density do not have much influence. The balance between the downward and after-impact lateral inertia and their resistance makes the lateral spread on a given mesh independent of liquid. Three regimes, full, partial, and no penetration, can be defined. A dissimilarity in the after-penetration jet length is detected. The length is inversely proportional to the emulsion's rising water content. The drop with the highest viscosity, together with ST, provides the highest resistance to penetration. Thus, the length reduces abruptly. When the after-impact penetration cone angle is studied, the average angle reduces with We for the highest viscosity emulsions. An abrupt rise in resistance is detected. The study's novelty lies in bringing out the viscosity's influence on the emulsion drop's impact on a mesh.

How Does the Interaction of the Human Thermal Plume and Breathing Affect the Microenvironment and Macroenvironment of an Elevator Cabin?

The details of the interaction of human thermal plume and breathing activities are simulated in the current study of an unsteady turbulent flow field in an elevator cabin. Air velocity and temperature distributions of the circulation flow pattern (i.e., the macroenvironment), the breathing-scale microenvironment’s characteristics, and the thermal plume’s fate are analyzed. The current study is aimed at showing how respiratory activities such as breathing and human thermal plumes affect the flow field and respiratory contaminants dispersion pattern in a nonventilated enclosed environment (the elevator cabin). The results from three cases, i.e., breathing thermal manikins, nonbreathing thermal manikins, and isothermal breathing manikins, are contrasted to unveil better the effects of human thermal plume and breathing on the flow field, including the velocity distribution, dispersion pattern of the exhaled contaminant, the human body’s heat transfer coefficient, and the large-scale flow pattern. Results reveal that breathing inhalation increases the upward velocity of the thermal plume on the one hand, which directly affects the microenvironment and indirectly impacts the macroenvironment due to the more vigorous reflected thermal plume. On the other hand, the upward thermal plume reduces the penetration length of the exhaled jet. Breathing activities create ring vortices that connect the microenvironment and the macroenvironment. The circulation flow features a downward flow in the cabin’s center, affecting the vortex strength and contaminant dispersion pattern. Overall, the human thermal plume and human breathing make comparable contributions to the resulting elevator-cabin flow characteristics.

The kinetic energy transfer analysis between the gas and the liquid in flow-focusing of the micro-jet

The present study uses computational fluid dynamics to analyse the kinetic energy transfer from the gas to the liquid phase, considering the significant influence of surface tension. The considered situation is the gas dynamic virtual nozzle, where the co-flowing gas focuses and accelerates the liquid jet. The experimentally validated half-space three-dimensional gas-liquid mixture model addresses the unsteady, incompressible, isothermal, Newtonian, low-turbulent two-phase flow. The continuity, momentum and the k-ω SST turbulence model are employed to resolve the fluid flow. The numerical solution is based on the finite volume method and volume of fluid approach with a geometric reconstruction scheme for tracking the gas-liquid interface. The total pressure of the gas, an indication of its energy, is tracked along streamlines and analysed spatially and temporarily. It is found that around 50 % of the focusing gas energy is transferred to the liquid jet before its breakup for the nozzle with Weber number 3.5, and gas and jet Reynolds number 1842 and 108, respectively. The linear regression between jet length and energy transfer efficiency is discovered. The presented methodology represents an essential tool for analysing and understanding the energy transfer process between the focusing gas and the liquid jet.

Simulation of non-Newtonian gas-focused micro-jets in chocked gas flow regime

Stable liquid jets are crucial for successful serial crystallography experiments. They are produced from gas dynamic virtual nozzles (GDVNs), where the liquid from an inner capillary is focused by a co-flowing gas from an outer converging capillary. Our previously investigated non-Newtonian jets with incompressible and compressible focusing gas under atmospheric conditions were extended towards compressible chocked gas under vacuum conditions. An axisymmetric GDVN was considered with a fixed gas flow rate of 15 mg/min and liquid flow rate of 40 µl/min. A mixture formulation of the laminar compressible multiphase problem was solved within finite volume method and volume of fluid framework. The jet lengths, diameters, velocities, and temperatures were analysed as a function of the power-law non-Newtonian modification of reference water. It is observed that the jets under vacuum conditions are thinner for Newtonian and shear-thickening fluids than those in the atmosphere. The jet length increases from shear-thinning to shear-thickening rheology but is not affected by the pressure. The shear produced at the nozzle outlet is similar for both pressure conditions but increases in downstream directions for vacuum conditions. Gas expanding into vacuum cools by ~100-150 K while the temperature of the liquid jet drops only by a few K.

Predictors of post-operative left atrioventricular valve regurgitation in pediatric patients with complete atrioventricular canal defects.

In infants with complete atrioventricular canal (CAVC) defects, post-operative left atrioventricular valve regurgitation (LAVVR) is a known major cause of morbidity and mortality and a common indication for re-operation. However, there is scarce data to identify risk factors for poor outcomes. Our study aims to find echocardiographic characteristics that predict post-operative LAVVR at discharge and 1-year follow-up. Retrospective cohort study of patients with initial CAVC repair at our hospital who were followed for 1 year between 2013 and 2022. Patients with major co-morbid conditions were excluded. Serial echocardiograms were reviewed. Anatomic details, quantitative and qualitative measure of LAVVR including the number of regurgitant jets, regurgitant jet length and vena contracta width, and ventricular function were collected. The time points measured include pre-operative transthoracic echocardiogram (TTE), post-operative transesophageal echocardiogram (PO-TEE), routine protocol based post-operative day 1 (POD1) TTE, discharge TTE and 1-year post-operative (1yPO) TTE. Paired t-tests, chi-square analysis, and linear regression analysis were performed comparing measured variables to LAVVR outcomes. Fifty-two patients were included; 92% had Trisomy 21. The majority were classified as Rastelli A (71%), others Rastelli C (29%). Only two patients had moderate or greater LAVVR pre-operatively. The mean age at repair was 125 ± 44 days. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year after backward stepwise regression. Of those with<moderate LAVVR on PO-TEE, 20% had worsening to≥moderate at discharge, but only 9% remained that way at 1 year. Of those with≥moderate LAVVR on PO-TEE, 40% improved to<moderate by 1 year. Two patients who worsened at 1 year, both secondary to likely cleft suture dehiscence. Only one patient required reoperation in the immediate post-operative period secondary to severe LAVVR due to suture dehiscence. Routine protocol-based POD1 echo did not have any association with altered outcomes. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year. A significant percentage (40%) of patient with≥moderate LAVVR on PO-TEE improved to<moderate by 1 year. Furthermore, routine protocol-based POD1 echo did not have any association with altered outcomes.

Large eddy simulation for jet noise characteristics of liquid rocket engine with guide groove

The study of jet noise characteristics of liquid rocket engines is a prerequisite for evaluating the noise level of rockets and effectively controlling the noise. To obtain the effect of engine operating and structural parameters on jet noise, the Large Eddy Simulation combined with the FW-H integration method is applied for the scaled engine with guide groove under different chamber pressures and nozzle expansion ratios. The simulation results show that the noise field distribution of the jet with a guide groove is highly symmetrical and has obvious directivity. The noise caused by jet impingement on the guide groove is strongly correlated to the distribution of high vorticity regions. Remarkably, higher chamber pressure leads to longer potential jet length, higher noise sound pressure levels, and greater enhancement effect of impact on noise. However, the frequency spectral characteristics are basically invariant. When the chamber pressure is constant, the increment of the nozzle expansion ratio in a certain range results in lower noise peak frequency and weaker impact effect.

Connecting in situ cone/jet length in electrospinning to fiber diameter and drug release for the rational design of electrospun drug carriers

Towards enabling the rational design of electrospun drug carriers, this study investigated relationships between cone/jet features in electrospinning and operating/solution parameters, fiber diameter or drug release profiles. Cone/jet length were visualized real-time during electrospinning of budesonide (BUD)-loaded poly(caprolactone) (PCL) and poly(D,L-lactide-co-glycolide) (PLGA) solutions. Voltage was varied for BUD-PCL at fixed drug/polymer ratio of 7.4 %, while solution concentration was modulated for BUD-PLGA resulting in drug/polymer ratios of 3.3–4.3 %. In both the BUD-PCL and BUD-PLGA systems, cone length and fiber diameter shared a strong linear relationship (R2 = 0.99, 0.98 respectively). PCL meshes exhibited bi-phasic release profiles, releasing ∼ 95 % BUD over 7 days regardless of fiber diameter, while PLGA meshes exhibited diameter-dependent controlled release. Despite the inconsistent relationship between fiber diameter and release, straight jet length in electrospinning was well-correlated with the Korsmeyer-Peppas parameter for BUD-PCL and the zero-order release parameter for BUD-PLGA (R2 = 0.71, 0.94 respectively). This approach of cone/jet visualization can reduce trial–error experiments and circumvent the cumbersome optimization of several electrospinning parameters for the design of drug-loaded electrospun meshes.

An XCT study on three-dimensional characteristics of a spout-fluid bed

Spout-fluid beds are widely used in the chemical and petrochemical industries for excellent mixing and heat and mass transfer properties. Understanding the behavior of jets in spout-fluid beds is crucial for optimizing these processes. In this paper, we present a novel experimental method for studying the three-dimensional characteristics of jets in spout-fluid beds using X-ray computed tomography. By employing a gas–solid flow parameter measurement system, we propose an accurate experimental fitting method for voxel voidage values, enabling the three-dimensional reconstruction of the time-averaged voidage in the entire flow field of a spout-fluid bed. These data are then used to develop an image processing algorithm for identifying and quantifying gas jets in the flow field, allowing for measures of jet length, volume, and diameter. We further investigate the effects of static bed height, spouting gas velocity, and fluidizing gas flowrate on the three-dimensional characteristics of jets.

Up, down, and round again: The circulating flow dynamics of flux-driven fractures

Fluid-filled fracture propagation is a complex problem that is ubiquitous in geosciences, from controlling magma propagation beneath volcanoes to water transport in glaciers. Using scaled analog experiments, we characterized the internal flow inside a propagating flux-driven fracture and determined the relationship between flow and fracture evolution. Different flow conditions were created by varying the viscosity and flux (Q) of a Newtonian fluid injected into an elastic solid. Using particle image velocimetry, we measured the fluid velocity inside the propagating fracture and mapped the flow across the crack plane. We characterized the internal flow behavior with the Reynolds number (Re) and explored Re values spanning five orders of magnitude, representing very different internal force balances. The overall fracture tip propagation velocity is a simple linear function of Q, whereas the internal velocity, and Re, may be vastly different for a given Q. We identified four flow regimes—viscous, inertial, transitional, and turbulent—and produced viscous and inertial regimes experimentally. Both flow regimes exhibit a characteristic flow pattern of a high-velocity central jet that develops into two circulating vortices on either side. However, they exhibit the opposite behavior in response to changing Q: the jet length increases with Q in the inertial regime, yet decreases in the viscous regime. Spatially variable, circulating flow is vastly different from the common assumption of unidirectional fracture flow and has strong implications for the mixing efficiency and heat transfer processes in volcanic and glacial applications.

Experimental study on the life and performance of an improved DC arc plasma torch

A novel DC arc plasma torch is designed in this paper in order to reduce the electrode erosion, and a series of experiments are carried out to investigate how to improve the lifetime and performance of the nitrogen DC arc plasma torch. The analysis of voltage characteristics of the plasma torch indicates that the interelectrode insert can increase the average arc voltage and the sudden expansion structure can reduce the voltage fluctuation, which is helpful to improve the working stability to some extent. The spectrum characteristics at the plasma torch outlet and the cold flow simulations show that the dual shielding gas mainly act near the anode and can effectively cover the entire anode wall. Combining the shielding gas distribution with anode heat transfer processes in argon and nitrogen plasma torch, it is inferred that argon shielding gas plays an important role on reducing the anode heat transfer processes in nitrogen plasma torch, which can effectively suppress the anode erosion. The life testing experimental results find that there is no significant erosion of the cathode, anode, and interelectrode insert after cumulative working time exceeding 20 h. The maximum nitrogen plasma jet length can reach ∼35 mm with the outlet jet temperature of about 20 000 K at the current of 100 A and nitrogen gas flow rate of 10 slm. The maximum average specific enthalpy and thermal efficiency are respectively about 14 MJ kg−1 and 75% in the nitrogen plasma torch. Therefore, this newly designed DC arc plasma torch not only can suppress the electrode erosion but also has good working performance, which is expected to have excellent application prospects.

Achievements and problems in studying the mechanism of thermal potential transfer regulation between liquids

The relevance of the study is determined by its focus on one of the key problems of the Ukrainian economy, namely the problem of energy resources, which is a necessary step in the development of resource management and planning strategies in the context of modern challenges and instability in the energy market. The purpose of the study is to determine the hydrodynamic and mass-heat transfer characteristics of the process of mixing liquids with different thermal potentials, and to investigate the influence of design factors on the intensity and efficiency of the flow jet. Experimental methods were used to specify the hydrodynamic and mass-heat transfer parameters of the liquid mixing process, and modelling was used to analyse the influence of design factors and develop a scientifically based methodology for calculating new device designs. An approach is obtained that allows solving two problems simultaneously: to decrease energy costs through their rational operation and to reduce environmental pollution, avoiding harmful emissions that occur during fuel combustion. The functional scheme of the test stand is described, the research methodology is presented, and statistical modelling of the influence of parameters on the length of the liquid jet is carried out. Studies of the energy efficiency of the initial stage of the interaction of thermal potentials during the generation of a liquid jet in a recuperative heat exchanger of mixed action to ensure storage conditions and potential movement in front of the nozzle are presented. A mathematical model for describing the length of a continuous water jet when flowing out of the nozzle is proposed and an analysis of the laminar flow of liquid from the nozzle is performed. The length of the continuous water jet when flowing out of the nozzle is determined and the technical capabilities of the process are identified. The efficiency of installing the tip in front of the nozzle for creating turbulent mixing and the method of controlling the water supply during the mixing of thermal potentials are determined. To control the water supply process, a step-by-step method has been developed that allows gradually increasing or decreasing the length of a continuous water jet through the nozzle. The results of the study provide an opportunity to optimise heat exchangers and mixing machines to increase their efficiency and productivity

On the three-dimensional flow evolution of a submerged synthetic jet with two circular orifices

Synthetic jet has shown promising applications in active flow control in recent years. Tomographic particle image velocity (Tomo-PIV) is an emerging flow field measurement, which can obtain three-dimensional flow field with a high spatial and temporal resolution to help us better understand the evolution of synthetic jet. Therefore, this paper uses a time-resolved Tomo-PIV system to measure and analyze the three-dimensional flow evolution of a submerged two-orifice synthetic jet. The measurement is conducted for stroke length L = 1.9, 2.6, and 3.0 while keeping the orifice diameter D and the distance between the two orifices s constant. Research results reveal that the three-dimensional flow evolution can be described as follows: first, two independent vortex rings form at the outlet of the orifice plate; next, these two vortex rings interact with each other and merge into a non-circular vortex ring, which then undergoes axis switching and vortex reconnection, with the tendency of splitting into two vortex rings. Furthermore, the position where the axis-switching finishes coincides with the location of the maximum mean streamwise velocity. When the stroke length of the synthetic jet is 2.6, the non-circular vortex ring undergoes a collision of vortices after the completion of the axis switching, resulting in the phenomenon of vortex ring bifurcation. However, the non-circular vortex ring fails to split into two vortex rings for stroke lengths of 1.9 and 3. Moreover, the entrainment of the synthetic jet increases with the increase in stroke length.

Flow characteristics of two-dimensional impinging synthetic jets

We aimed to elucidate the behavior of impinging synthetic jets against the surface of a wall placed near the slot exit. Synthetic jets with various frequencies were used, and a rectangular body of finite length (target plate) was placed downstream of these jets. The flows were visualized by the smoke-wire method and numerical simulation, and the velocity distributions around the target plate were measured using a hot-wire anemometer. The flow fields of steady continuous jets and synthetic jets with unsteady characteristics were compared, and their flow characteristics were explored. We experimentally found that the flow field depends on the dimensionless target plate length and dimensionless frequency of the synthetic jet for a fixed distance from the slot to the target plate. Furthermore, at low frequencies, the behavior after impinging the target plate was similar to that observed for a continuous jet. Additionally, it has been confirmed that these results qualitatively agree with the numerical simulation results.

OPTICAL-GRAPHIC STUDIES OF HYDROGEN ADDITIVES’ EFFECTS ON DIESEL FUEL ATOMIZATION PARAMETERS

This paper considers a promising method of enhancing the effectiveness of diesel engines. This method uses the addition of hydrogen in a small amount (up to 2% by mass). The hydrogen additive is added to the high-pressure fuel line before the injector. Based on the experimental findings, a reduction in the engine’s specific fuel consumption of up to 3% was achieved in comparison to the baseline configuration. A research study was conducted at the Admiral Makarov National University of Shipbuilding using a newly established experimental setup to assess the impact of hydrogen additives on primary fuel delivery, spray characteristics, and overall engine performance. Among the experiments conducted, one investigated fuel atomization parameters, focusing on how the presence of hydrogen in the fuel influenced the fuel jet’s characteristics. A high-speed camera with a high resolution was used to record the optical-graphic study to isolate and extract individual shots of the torch’s expansion, thus obtaining images devoid of ignition and flickering. After conducting image processing and constructing jet models, along with subsequent analysis, it becomes apparent that the addition of hydrogen to the primary fuel results in an enhancement of spray quality. The torch volume expanded by approximately 10% to 15%, while the jet length diminished by approximately 8% to 10%. Consequently, the average diameter of the atomized fuel droplets decreases by up to 10%, with the extent of reduction contingent upon the initial parameters and configurations.

Experimental study of breakup and atomization characteristics of liquid carbon dioxide jet under high-pressure environment

Considering the working conditions of a Mg/CO2 rocket engine for Mars exploration, an experimental investigation was carried out to study the breakup and atomization properties of a liquid CO2 jet in a high-pressure environment. It is shown that the pressure ratio has a significant effect on the location and process of jet evaporation, resulting in significant difference in jet morphology and breakup characteristic. Two dividing points were identified, one near the CO2 triple point and the other near the saturation point. As the pressure ratio increases, the thermodynamic driving force for jet breakup weakens, leading to larger droplet sizes. The breakup length of the free round jet and Sauter mean diameter are functions of the Weber number and Jacob number, which are influenced by vapor content, injection velocity, and gas-liquid density ratio, in the mass flowrate range of 5.9–9.1 g/(mm2·s). A thermodynamic mechanism dominates when the ambient pressure in the atomize room is low enough, resulting in an unimodal distribution of droplet sizes. When the ambient pressure is in the range of 1–2.5 MPa, both thermodynamic and mechanical breakup mechanisms are active, resulting in a bimodal distribution of droplet sizes.

Outcomes of latent rheumatic heart disease: External validation of a simplified score in patients with and without secondary prophylaxis

BackgroundSecondary antibiotic prophylaxis reduces progression of latent rheumatic heart disease (RHD) but not all children benefit. Improved risk stratification could refine recommendations following positive screening. We aimed to evaluate the performance of a previously developed echocardiographic risk score to predict mid-term outcomes among children with latent RHD. MethodsWe included children who completed the GOAL, a randomized trial of secondary antibiotic prophylaxis among children with latent RHD in Uganda. Outcomes were determined by a 4-member adjudication panel. We applied the point-based score, consisting of 5 variables (mitral valve (MV) anterior leaflet thickening (3 points), MV excessive leaflet tip motion (3 points), MV regurgitation jet length ≥ 2 cm (6 points), aortic valve focal thickening (4 points) and any aortic regurgitation (5 points)), to panel results. Unfavorable outcome was defined as progression of diagnostic category (borderline to definite, mild definite to moderate/severe definite), worsening valve involvement or remaining with mild definite RHD. Results799 patients (625 borderline and 174 definite RHD) were included, with median follow-up of 24 months. At total 116 patients (14.5%) had unfavorable outcome per study criteria, 57.8% not under prophylaxis. The score was strongly associated with unfavorable outcome (HR = 1.26, 95% CI 1.16–1.37, p < 0.001). Unfavorable outcome rates in low (≤6 points), intermediate (7–9 points) and high-risk (≥10 points) children at follow-up were 11.8%, 30.4%, and 42.2%, (p < 0.001) respectively (C-statistic = 0.64 (95% CI 0.59–0.69)). ConclusionsThe simple risk score provided an accurate prediction of RHD status at 2-years, showing a good performance in a population with milder RHD phenotypes.

Development of a pulse modulated sub-radio frequency power supply for atmospheric pressure plasma devices.

The effect of pulse-modulated sub-RF range (100 kHz-1MHz) excitation on atmospheric pressure argon plasma jet characteristics is studied. For this, a suitable power supply is developed, offering a sub-µs rise time with control of different parameters, such as voltage amplitude, pulse modulation frequency in the range of 1-30kHz, and an oscillation frequency of ∼520kHz, which can affect the plasma behavior. Plasma characteristics, such as reactive species generation, ionic composition, plasma plume length, and gas temperature, are evaluated qualitatively and quantitatively by employing diagnostics such as optical emission spectroscopy, molecular beam mass spectrometry, and optical imaging. Experimental observations indicate that the gas temperature of the plasma jet and plume length increase with the applied voltage for all pulse modulation frequencies, with a maximum value of ∼(325 ± 2K) and a maximum length of ∼(23 ± 3mm), respectively, at 30kHz and 9 kVpp. The emission intensities of OH• and O• lines show an incremental behavior with the applied voltage across all pulse modulation frequencies. The relative yield of different positive (OH+, O+, etc.) and negative (OH-, O-, etc.) ions also increases with the applied voltage for all pulse modulation frequencies with maximum values of ∼(7.6%, 9.9%) and (3.9%, 9.4%), respectively; these are relatively close to RF excited ionic concentrations reported previously. Attaining a high plasma length and species yield signify the features of both kHz and RF atmospheric plasmas. This study offers significant insights and flexibility into exploring the impact of different RF frequency regimes on plasma characteristics.

The Impact of a Handheld Ultrasound Device in a Rheumatic Heart Disease Screening Program in Ethiopia

Background: Rheumatic heart disease affects 33 million people in low and middle income countries and is the leading cause of cardiovascular death among children and young adults. Penicillin prophylaxis prevents progression in asymptomatic disease. Efforts to expand echocardiographic screening are focusing on simplified protocols, non-physician ultrasonographers, and portable ultrasound devices, including handheld ultrasound. Recent advances support the use of single-view screening protocols. With the increasing availability and low cost of handheld devices, studies are needed to evaluate their performance in these settings.&#x0D; Methods: We conducted a retrospective study comparing the rate of screen positive ultrasounds before and after the use of a handheld ultrasound in an RHD screening program in Ethiopia. We also performed a cross-sectional device comparison in 19 at-risk school-children participating in the rheumatic heart disease screening program.&#x0D; Results: Between March of 2019 and Jan of 2022, 6631 children were screened for rheumatic heart disease of whom 4029 were screened after the introduction of a handheld device. Before the use of the handheld ultrasound device 291 (11.2%) children had a screen positive ultrasounds compared with 167 (4.1%) afterwards (p &lt; 0.001). We also compared non-expert to expert interpretation by device and found a significant difference in interpretation for the Lumify (p=0.025). There was a trend towards shorter jet length by color Doppler in the handheld ultrasound device for both expert and non-expert review. &#x0D; Conclusions: Our study highlights that the screen-positive rate in a RHD screening program is influenced by the device being used in the screening process.&#x0D;

The Spatial Arrangement of The Electric Field in the Needle-Plate Electrospinning

&lt;p class="IJASEITAbtract"&gt;The electric field distribution of the Neddle-Plate (NP) electrospinning set up has reported due to the simple classical electrodynamics solutions. The charge is assumed to distribute uniformly in the needle (nozzle) and the collector (plate). The electric field has an influence only in the early stage of the electrospinning process. The electric field and the viscosity of the jet fluid have caused the bending of the straight jet. The high viscosity of the fluid can preserve the straight jet length much longer. The electric field gives the initial angular momentum of the jet due to the whipping motion of the jet. For the area away from the nozzle, the electric does not influence the whipping motion. Then the whipping motion solely due to the influence from the charge repulsion of the jet fluid and the evaporation of the solvent.&lt;/p&gt;