Injection Of Type Research Articles

Differential adsorption of analyte and deuterated analogue onto the rotor seal of the injector in high-performance liquid chromatography/electrospray ionisation mass spectrometry.

Samples were injected onto the HPLC system via either a Valco C14W.1 internal sample injector or a Rheodyne 7125 injector, both with dissimilar Vespel rotor seals, and linked to a quadrupole time-of-flight (QTOF) mass spectrometer. Alternatively, samples were infused directly into the mass spectrometer via a syringe-driver. Electrospray ionisation in positive mode was used in both cases. Experiments demonstrated significant differential adsorption of the analyte (RAC inhibitor, NSC23766) and its tri-deuterated internal standard onto the Vespel rotor seal, with the latter seeming to be preferentially adsorbed. The deuterated analogue also showed lower electrospray sensitivity, as demonstrated by syringe infusion of a mixture of the compounds, compared with their separate infusion at the same concentration. This study has demonstrated the problem of differential adsorption onto HPLC Vespel rotor seals, and that the use of a stable-isotope-labelled analogue as internal standard does not guarantee the constancy of the analyte/internal response ratio in quantitative methods. The partial solution was to work at much higher concentration where adsorption, whilst still apparent, was relatively insignificant.

Influence of the injector setup on digital and continuous injection rate-shaping performance in diesel engine passenger cars

Injection continuous rate-shaping strategies, realized by means of state-of-the-art Common rail solenoid and direct acting piezoelectric injectors, have been tested at a dynamometer cell. NOx, soot, combustion noise and heat release rate data, pertaining to the two injector types, have been compared, based on a pilot-main injection calibration. The performance of the solenoid injectors resulted to be in line with that of the direct acting piezoelectric injectors.Digital and continuous rate-shaping strategies have then been investigated at a hydraulic rig in solenoid injectors. The cycle-to-cycle dispersion in the injected mass increases significantly in the closely-coupled injection regime, where the overall injected quantity raises up as the dwell time progressively reduces. However, as the dwell time is diminished to values well within the injection fusion zone, the cycle-to-cycle dispersion of the injected mass again improves and this confirms that is possible to implement effective continuous injection rate-shaping schedules also for the solenoid injectors.A previously developed one-dimensional model of a solenoid fuel injection system has been applied to perform parametric analyses on the solenoid injector setup: mechanical, electromagnetic and hydraulic parameters have been changed in order to investigate their effect on the closely-coupled injections. The objective is to provide design keys for realizing more efficient injection rate-shaping schedules in order to improve engine emissions, fuel consumption and combustion noise.Finally, the performance of two production solenoid injectors, which feature a different internal layout, has been compared in the short dwell time range and the experimental results have been successfully interpreted on the basis of the injector parametric analyses.

Study on the Common Rail Type Injector Nozzle Design Based on the Nozzle Flow Model

In this paper, a nozzle flow model was used to design an injector nozzle and obtain initial spray conditions for the dimethyl ether (DME) common rail-injection system. In order to deliver the same amount of energy as that provided by diesel at a low injection pressure of 50 MPa, the injector for DME needs nozzle holes with larger diameters and a higher SAC volume for the same injection duration. In addition, the needle lift and needle seat diameter should be increased to maintain a minimum flow area ratio. Although the vapour pressure and maximum injection pressure of DME are lower than those of diesel, the nozzle in a DME system showed higher discharge coefficients and effective nozzle exit diameters for the same injection duration owing to low kinematic viscosity. However, because the maximum injection pressure in DME is lower than that with diesel, and the length of the cavitation region is narrower.

Soft tissue distribution pattern of facial soft tissue fillers with different viscoelastic properties.

Soft tissue filler product distribution and tissue integration have been shown to depend on myriad factors including the injector type, injector size, and injection angle. This study aims to investigate the magnitude of product spread across fascial soft tissue layers in relation to product viscoelastic properties. A total of 168 injection procedures were conducted in two female Caucasian body donors with a mean age of 80years (range: 79-81) and a mean body mass index of 23.6kg/m2 (range: 21.0-26.6). The injection procedures were performed in the forehead, scalp, zygomatic arch, mandible, clavicle, and sternum. The injected materials included Belotero® Soft, Belotero® Balance, Belotero® Intense, Belotero® Volume, Radiesse® , and Radiesse® Plus. Layer-by-layer dissections were performed to investigate the vertical distribution of the injected product. The mean product spread was for Belotero® Soft 4.54±0.91; Belotero® Balance 3.85±1.19; Belotero® Intense 3.04±1.34; Belotero® Volume 2.58±1.27; Radiesse® 1.31±0.47; and Radiesse® Plus 1.27±0.45 with P<.001. Bivariate correlations between product spread and storage modulus (G') revealed an inverse relationship of moderate strength with rp =-0.651 and P<.001. The results of the present study revealed that products that were more fluid and less viscous distributed into more superficial fascial layers than products that were less fluid and more viscous (P<.001). This relationship held true irrespective of injected location.

Experimental study of effects of type of injectors on the performance of gas generator of liquid rocket engine

The role of the injector is atomization and mixing. It dictates the size and geometry of the combustion chamber and gas generator. Experiments are conducted with water-cooled adjustable length gas generator for a liquid rocket engine with two types of injectors at a lower mixing ratio. Tests are conducted at characteristic length of 1.75 and 4.27 m. Liquid oxygen and kerosene are used as propellants. Single pressure swirl coaxial injector and three like doublet impinging injectors are used. Combustion performance is studied and compared on the base of characteristic velocity. Characteristic velocity is found high at short length but is found low at larger length for pressure swirl injector as compare to impinging injectors.

A new type of automatic ball injector for multistage fracturing

Ball-drop fracturing is a kind of technology that is commonly used for multistage fracturing of shale gas horizontal wells. At present, the ball injector cannot satisfy the operation demands of large bore and small spacing fracturing of shale gas wells due to its disadvantages, such as a small size of fracturing ball, a limited number of balls, complicated structure and poor applicability. In this paper, a new type of automatic ball injector with rotating plate and large bore was designed. There is a ball storage at the upper part of the ball injector and a ball injecting mechanism inside the pedestal at the lower part. And the ball injecting mechanism is controlled by the drive motor to inject the balls one by one. Then, collision analysis was carried out on its ball injecting process by using finite element method (FEM). Finally, simulation and prototype tests were conducted by using the arbitrary Lagrangian–Eulerian (ALE) mesh adaption method and the coupled smoothed particle hydrodynamics method (FEM–SPH). And the following research results were obtained. First, in the process of ball collision, the maximum equivalent stress, equivalent plastic strain and displacement are generated at the edge of the rotating plate. The maximum stress is about 600 MPa, which is less than the yield strength of 42CrMo (930 MPa), so the strength requirement is satisfied with a certain safety margin. Second, the prototype successfully passes the continuous ball injecting test of 12-stage fracturing process with the ball diameter of 64–108 mm and the ball contrast of 4 mm. In conclusion, this automatic ball injector with rotating plate and large bore is advantageous with simple operation and wide applicability and can effectively address the needs of multistage fracturing of shale gas horizontal wells.

A versatile experimental system for tracking ultrafast chemical reactions with X-ray free-electron lasers.

An experimental system, SPINETT (SACLA Pump-probe INstrumEnt for Tracking Transient dynamics), dedicated for ultrafast pump-probe experiments using X-ray free-electron lasers has been developed. SPINETT consists of a chamber operated under 1 atm helium pressure, two Von Hamos spectrometers, and a large two-dimensional detector having a short work distance. This platform covers complementary X-ray techniques; one can perform time-resolved X-ray absorption spectroscopy, time-resolved X-ray emission spectroscopy, and time-resolved X-ray diffuse scattering. Two types of liquid injectors have been prepared for low-viscosity chemical solutions and for protein microcrystals embedded in a matrix. We performed a test experiment at SPring-8 Angstrom Compact free-electron LAser and demonstrated the capability of SPINETT to obtain the local electronic structure and geometrical information simultaneously.

Simulation of mass and heat transfer in liquid hydrogen tanks during pressurizing

In order to accurately predict the heat and mass transfer behaviors and analyze key factors affecting pressurization process in the hydrogen tank, a comprehensive 2D axial symmetry Volume-Of-Fluid (VOF) model is established by Computational Fluid Dynamics (CFD) method. The effects of phase change, turbulence and mass diffusion are included in the model and relationships between physical properties and temperature are also comprehensively considered. The phase change model is based on Hertz-Knudsen equation and the mass transfer time relaxation factor is determined by the NASA’s experimental data. The mass diffusion model is included in gaseous helium pressurizing. The key factors including the inlet temperature, inlet mass flow rate, injector types and pressurizing gas kinds are quantitatively analyzed. Compared with the experiment, the simulation results show that the deviation of pressurizing gas mass consumption, condensing mass and ullage temperature are 3.0%, 7.5% and 4.0% respectively. The temperature stratification is existed along the axial direction in the surface liquid region and the ullage region, and the bulk liquid is in subcooled state during pressurizing. The location of phase change mainly appears near the vapor–liquid interface, and the mass transfer expressing as condensation or vaporization is mainly determined by the heat convection and molecular concentration near the vapor–liquid interface. The key factors show that increasing the inlet temperature and inlet mass flow rate could shorten the pressurizing time interval and save the pressurizing gas mass. The proportion of the total energy addition of the tank absorbed by the ullage region, the liquid region and the tank wall respectively is greatly influenced by the injector types and more heat transferred into the ullage would result in a faster pressure rising rate. Gaseous hydrogen pressurization has a higher efficiency than gaseous helium pressurization. The simulation results presented in this paper can be used as a reference for design optimization of the pressurization systems of cryogenic liquid launch vehicles so as to save the mass of pressurizing gases and shorten the pressurizing time interval.

Hollow pellet injection for magnetic fusion

The precise delivery of mass to burning plasmas is an area of growing interest in magnetic fusion (MF). The amount of mass that is necessary and sufficient can vary depending on such parameters as the type of atoms involved, the type of applications, plasma conditions, mass injector, and injection timing. Motivated by edge localized mode (ELM) control in H-mode plasmas, disruption mitigation and other applications in MF, we report the progress and new possibilities in mass delivery based on hollow pellets. Here, a hollow pellet refers to a spherical shell mass structure with a hollow core. Based on an empirical model of pellet ablation, coupled with BOUT++ simulations of the ELM triggering threshold, hollow pellets are found to be attractive in comparison with solid spheres for ELM control. By using hollow pellets, it is possible to tailor mass delivery to certain regions of edge plasmas while minimizing core contamination and reducing the total amount of mass needed. We also include the experimental progress in mass delivery experiments, in situ diagnostics and hollow pellet fabrication, and emphasize new experimental possibilities for ELM control based on hollow pellets. A related application is the disruption mitigation scheme using powder encapsulated inside hollow shells. Further experiments will also help to resolve known discrepancies between theoretical predictions and experiments in using mass injection for ELM control and leading to better predictive models for ELM stability and triggering.

Performance comparison of oxidizer injectors in a 1-kN paraffin-fueled hybrid rocket motor

To investigate the effects of oxidizer injection on the performance of hybrid rocket motors (HRMs), we have designed, manufactured and tested four types of injector: showerhead (SH), hollow-cone (HC), pressure-swirl (PSW) and vortex (VOR). This study is motivated by the fact that the experimental measurements of N2O/paraffin firings are poorly presented in the open literature. Besides few publications are dedicated to the characterization of novel types of injectors in hybrid rocket propulsion application such as HC, PSW, and VOR. It is advantageous that the study was conducted in the same motor configuration, with the advantage that it allowed to compare the performance of different types of injectors.This paper analyzes the influence of the oxidizer injector design on the main performance parameters, such as fuel regression rate, specific impulse and combustion efficiency. First, in order to observe injector spray qualities, a series of cold tests using liquid water and liquid nitrous oxide are carried out, providing a good understanding of the spray profiles. Then, the motor performance data is obtained by a series of firing tests using N2O as oxidizer and paraffin as fuel. Comparison of the various injectors data is made with the same average oxidizer mass flux and feeding pressure. The showerhead is used as a benchmark in this study. During this experimental analysis, the VOR injector exhibits the highest regression rate, followed by HC and SH. Because the assessment of the regression rate was not enough to explain all the effects of the injectors on the motor performance, firing tests of small-scale hybrid motor have been carried out. In terms of spray properties, the PSW exhibits significant differences compared with the other injectors; it generates the smallest Sauter Mean Diameter (SMD) in the formed spray and achieves good atomization. In spite of the fact that the PSW injector leads to the lowest regression rate, it provides good specific impulse, increases the oxidizer-to-fuel ratio (O/F), as well as a uniform and smooth consumption of the paraffin fuel grain. VOR leads to the highest specific impulse. In terms of stability, VOR, HC and SH injectors exhibit lower oscillations in the chamber pressure. Some observations are made on exhaust plume intensity developed during combustion, and in firing tests with SH a blow-out phenomenon occur often. Similarly to liquid engines, it is possible in hybrid motors to increase the global propulsive performance using alternative designs of the injection system.

In Vitro Simulation of Tissue Back-Pressure for Pen Injectors and Auto-Injectors

The aim of this project was to show that tissue back-pressure can be measured in vitro using a simple pneumatic model. A thorough literature study revealed 4 relevant papers all describing in vivo studies. One of these studies where the subcutaneous tissue back-pressure was determined in 11 patients was used as a reference for the present work. A pneumatic model capable of simulating the back-pressure and the diffusion of drug during subcutaneous injection was developed. The in vitro model was tested using the same type of pen injector as used in the reference study. Comparison of the results revealed that the measured pressure in the in vitro experiments was similar to the subcutaneous tissue back-pressure measured in vivo. G30 0.3 × 8.0 mm and G32 0.23/0.25 × 4.0 mm needles were used for the in vitro experiments, whereas a G31 0.25 × 6.0 mm needle was used for the in vivo experiments. This is one possible explanation of approximately 30 μL/s higher flow rates for the in vitro experiments compared to the in vivo experiments. The low-complexity model allows repeated measurements and provides a stable data output paving the way for measuring subcutaneous back-pressure in vitro.

Focusing of Microcrystals and Liquid Condensates in Acoustofluidics

Manipulation of high-density materials, such as crystals and liquid condensates, is of great importance for many applications, including serial crystallography, structural and molecular biology, chemistry, and medicine. In this work, we describe an acoustic technique to focus and harvest flowing crystals and liquid condensates. Moreover, we show, based on numerical simulations, that the acoustic waves can be used for size-based particle (crystals, droplets, etc.) separation. This is an essential technological step in biological research, medical applications, and industrial processes. The presented technology offers high precision, biocompatibility, ease of use and additionally, is non-invasive and inexpensive. With the recent advent of X-ray Free Electron Laser (XFEL) technology and the associated enormous importance of a thin jet of crystals, this technology might pave the way to a novel type of XFEL injector.

Performance analysis of injectors for a hybrid propulsion system

This paper presents a study about injectors, where the radial injector was evaluated. This type of injector was chosen because only a small amount of information on it was found. Thus, the radial injector will be compared with other two types of injectors, the orifice plate and the swirl, in terms of parameters, such as discharge coefficient (Cd), regression rate r, and specific impulse (Isp). In respect of the regression rate, the values appeared increasingly with the test pressure and, consequently, with the injection pressure. Thus, each injector model responded in the same way as for the regression rate behavior; however, the same behavior was not observed in relation to the specific impulse.

Real-Time Light-Guided Vocal Fold Injection: Ex Vivo Feasibility Study in a Canine Model.

The transcricothyroid (CT) membrane approach is a good option for office-based vocal fold injection (VFI). However, because the needle tip is invisible during injection using the CT approach, precise localization requires a high level of experience, and mastering this approach involves a steep learning curve. To overcome current limitations, we conceptualized a novel technique: real-time light-guided VFI (RL-VFI), which enables simultaneous VFI under direct visualization of the lighted needle tip. Herein, we aimed to verify the feasibility of RL-VFI in cadaveric canine model, simulating the setting of office-based VFI, as well as to explore its clinical usefulness. Animal study. A customized prototype device was developed. It consisted of three parts: light source, controller, and injector. Light source comprised laser diodes of two wavelengths (635 nanometers [nm], red; 532 nm, green). Four types of injector were developed using 40-mm needles of 23- and 25-gauge and optic fibers of 50 and 100 μm. ex vivo canine larynx was prepared for the experiment. Flexible laryngoscopy system was used to examine canine vocal folds. Various routes from three insertion points (3 mm, 10 mm, and 17 mm from the midline) were validated using the device. Regardless of the injection routes, the location of the needle tip was accurately indicated by light. RL-VFI was feasible under light guidance without difficulties. Moreover, precise and simultaneous re-injection could be performed at the intended point using the device. We introduced RL-VFI using our customized prototype device in an ex vivo canine larynx, simulating the setting of office-based VFI. Clinical application of RL-VFI will improve safety and precision of CT approach, as well as expand its applications in laryngology. NA. Laryngoscope, 129:935-942, 2019.

Theoretical study to determine the proper injection system for upgrading fuel system of diesel engine om357 to common rail system

In this research, we tried to investigate all the fuel injection systems of diesel engines in order to select the most suitable fuel injection system for the OM357 diesel engine to achieve the highest efficiency, maximize output torque and reduce emissions and even reduce fuel consumption. The prevailing strategy for this study was to investigate the effect of injection pressure changes, injection timing and multi-stage injection. By comparing the engines equipped with common rail injection system, the proposed injector for engine OM357 is solenoid, due to the cost of this type of injector, MAP and controller (ECU). It is clear that this will not be possible only with the optimization of the injection system, and so other systems that influence engine performance such as the engine's respiratory system and combustion chamber shape, etc. should also be optimized.

Impact of fish feeds, fish oils, and amino acids on the performance of airlift pumps

The impact of the addition of a wide variety of commercial, experimental, and larval feeds as well as fish oils, specific lipid products, amino acids, and surfactants on airlift pumping rates were documented. At 250 min after addition, the airlift flow rate varied from 12% to 102% of baseflow for diffuser injection but only 77 to 85% of base flow for direct injection. As a group, the fish and algal-based oils had the greatest impact on airlift flow rate. It is hypothesized that the impact of feed addition is due to lipids and surface-active compounds leaching out of the feed and increasing bubble size. There was a significant correlation between gas holdup and airlift pumping rate. Higher gas holdup was positively correlated with higher water flows. There was also a wide range in speed and range of flow rate recovery; flow recovery may depend on adsorption of lipids on the tank walls or chemical reactions. There was a positive correlation between lipid content and flow reduction, but the physical characteristics of the feed and specific fatty acid profiles of the feed may be important. The use of performance information based on clean water tests may significantly over-estimate pumping rates of airlift pumps. For critical applications, on-site evaluation using actual airlift pumps and feeds may be needed. While feed addition had much more impact on the performance of airlift pumps using diffuser injection compared to direct injection, the significantly higher efficiency of diffuser injection makes this injector type a better choice for many applications.

Uniformity index measurement technology using thermocouples to improve performance in urea-selective catalytic reduction systems

The current commonly used nitrogen oxides (NOx) emission reduction techniques employ hydrocarbons (HCs), urea solutions, and exhaust gas emissions as the reductants. Two of the primary denitrification NOx (DeNOx) catalyst systems are the HC-lean NOx trap (HC-LNT) catalyst and urea-selective catalytic reduction (urea-SCR) catalyst. The secondary injection method depends on the type of injector, injection pressure, atomization, and spraying technique. In addition, the catalyst reaction efficiency is directly affected by the distribution of injectors; hence, the uniformity index (UI) of the reductant is very important and is the basis for system optimization. The UI of the reductant is an indicator of the NOx conversion efficiency (NCE), and good UI values can reduce the need for a catalyst. Therefore, improving the UI can reduce the cost of producing a catalytic converter, which are expensive due to the high prices of the precious metals contained therein. Accordingly, measurement of the UI is an important process in the development of catalytic systems. Two of the commonly used methods for measuring the reductant UI are (i) measuring the exhaust emissions at many points located upstream/downstream of the catalytic converter and (ii) acquisition of a reductant distribution image on a section of the exhaust pipe upstream of the catalytic converter. The purpose of this study is to develop a system and measurement algorithms to measure the exothermic response distribution in the exhaust gas as the reductant passes through the catalytic converter of the SCR catalyst system using a set of thermocouples downstream of the SCR catalyst. The system is used to measure the reductant UI, which is applied in real-time to the actual SCR system, and the results are compared for various types of mixtures for various engine operating conditions and mixer types in terms of NCE.

Swirl Injector for Premixed Combustion of Hydrogen–Methane Mixtures

In the field of combustion, a special attention was given lately especially to the search for new, greener and more efficient fuels. Among them, hydrogen is intensely studied worldwide as a possible alternative fuel since new ways for producing and transporting it developed lately. Different studies are trying to confirm the possibility of the hydrogen transport using the existing natural gas distribution network, by mixing the two gases. Because the properties of the new mixture influence the combustion parameters, using the existing equipment would face new problems, like the risk of flashback, the effects of higher temperatures, and the modification of the flame front. Hence, new solutions are needed. In this context, this paper presents a newly developed and patented type of injector, designated for the combustion of the premixed hydrogen–methane fuel in various proportions. Based on the characteristics and dimensions of an existing combustion chamber of a gas turbine, different types of injectors were numerically simulated and compared. After the analysis of the results, the preliminary conclusions lead to a first swirl injector made from titanium alloy. The new type of swirled injector was tested on a cheap, simplified low pressure rig, designed to have similar dimensions to the initial combustion chamber, for preliminary validation of the main characteristics and of the stability of the new injector. The experiments indicated good lean blowout characteristics, and the promising results are encouraging for more future tests on a complex experimental setup, for optimizing the final solution.

The influence of petrol injection parameters on the structure of geometry of fuel spray injected from outward-opening injectors

The paper deals with the issue of determining the geometry of fuel spray generated by the outward-opening type of injectors. The design of the outward-opening type injector is the reason for the initial fuel flow taking a circular shape (an empty cone). With increasing pressure of the injected fuel this geometry changes into a square one. The aim of the research was to determine the conditions of these changes and to propose how to define the geometry in the form of an indicator z (accepting positive values – for circular geometry, and negative values – for square geometry) as well as to generalize the equation zeq making it possible to determine the indicator of the fuel spray geometric structure changes. The defined indicator z shows that fuel injection pressure exceeding 15 MPa plays an important role in changing the geometric structure of the fuel spray. The back pressure of the medium into which the fuel is injected does not affect the determined value of the indicator. Additionally, an indicator of variation of radial penetration of the fuel spray CoV(Sr) and the indicator of linear to radial fuel spray penetration Sl/Sr-av were determined, which only under certain conditions can replace the z indicator.

Mathematical Models of Electro-Magnetohydrodynamic Multiphase Flows Synthesis with Nano-Sized Hafnium Particles

The multiphase fluid flow under the influence of electro-magnetohydrodynamics (EHD) is investigated in this study. The base fluid contains hafnium particles. Two illustrative models namely fluid phase and particulate phase are considered for three different geometries having great importance in both industrial and mechanical usage. The impact of pertinent parameters from different aspects is illustrated graphically with requisite discussion keeping in view their physical aspects. The stream lines are also erected to highlight their physical importance regarding the flow patterns. In addition, the paper is terminated by making a comparison with the existing literature as a limiting case of considered problem to confirm the validations of achieved results and hence found in excellent agreement. This model can be used to design and engineer for nozzle or diffuser type of injectors in the latest models of automobiles to improve their performance and reduce the consumption of fuel.