Injection Mode Research Articles

Influence of technological mode of injection moulding on the properties of nanocomposites based on low density polyethylene and thermosol of household waste

The results of the study of the influence of the technological mode of injection molding on the pattern of changes in the physicomechanical properties of nanocomposites based on low density polyethylene filled with a thermosol of household waste are presented. As an object of study, nanocomposites containing 10 and 40 wt.% of thermosol are used.

A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5-fluorouracil and its metabolite in human plasma.

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1-1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11-0.14 ng/ml) and satisfactory analyte relative recovery (97.4-99.7%) with relative standard deviations of 4.6-9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies.

Effects of diesel pre-injection on the combustion and emission characteristics of a common-rail diesel engine fueled with diesel-methanol dual-fuel

The diesel-methanol dual-fuel (DMDF) combustion was performed on a six-cylinder, common-rail diesel engine. To this end, methanol was premixed with air in the intake pipe and ignited by the directly injected diesel fuel in the cylinder. Single and double injection were considered in this study. Double injection included pre-injection and then main injection. The aim was to investigate, in comparison with the single injection strategy, what effects diesel pre-injection strategy may have on the combustion and emission characteristics of the test DMDF engine. The experiment was carried out at 1400r/min, 50% load and different values of the co-combustion ratio. The results show that, for double injection compared with single injection mode, both the heat release rate and the maximum cylinder temperature become lower, while the cycle-to-cycle variation of indicated mean effective pressure becomes higher. The results of emission characteristics indicate that, under double injection mode, the HC emissions decrease, while those of CO, NOx and PM increase. The NOx emissions and the size of particular matter both increase with co-combustion ratio, when diesel pre-injection was applied.

Diesel injection strategies for reducing emissions and enhancing the performance of a methanol based dual fuel stationary engine

The effect of injection strategies of diesel on combustion, performance and emissions of a single cylinder, light duty, common rail, and methanol-diesel dual fuel engine were investigated. Methanol was port injected and experiments were carried out at a speed of 1500 rpm, brake mean effective pressure of 4.3 bar (75% rated load) and methanol to diesel energy share of about 50%. The directly injected diesel was first introduced as a single pulse, then as two pulses – Pilot and main injection and finally as three pulses – pilot, main and post injection. Single pulse injection of diesel resulted in delayed combustion which lowered the combustion stability and brake thermal efficiency. With the pilot main injection strategy combustion rate, peak combustion temperature and combustion stability were enhanced due to increased charge reactivity. Further, hydrocarbon and carbon monoxide emissions were reduced due to the complete combustion of methanol. The pilot with main and post injection strategy could reduce the rate of pressure rise, Nitric oxide levels and average in-cylinder temperature as compared to the pilot main injection mode. Through proper selection of the quantity and timing of the post injected diesel (1.25 mg/cycle and 5°crank angle after top dead center) which is employed along with pilot and main injections, a significant reduction in Hydrocarbon, Carbon mono-oxide, Nitric oxide and Soot emissions with good combustion stability and low ringing index could be achieved in the dual fuel mode.

Avalanche Delay and Dynamic Triggering in GaAs-Based S-Diodes Doped With Deep Level Impurity

The article is concerned with a detailed switching delay effect exhibited by avalanche S-diodes-superfast GaAs closing switches doped with deep Fe centers. The current and voltage time dependences are simulated in a simplified generator. The dynamic electric field and charge profiles in the structures are calculated. This article describes an impact that Fe capture cross sections of free charge carriers have on delayed switching. The simulation results show that delayed switching is associated with deep center recharging in a double injection mode due to three different processes. There are two different delay mechanisms to be herewith distinguished. A delay effect is experimentally viewed to control the dynamic switching voltage (and the avalanche breakdown voltage) using constant voltage adjustment capability enabled by a triggering circuit supply. The authors demonstrate the way it is possible to adjust the amplitude of current nanosecond pulses in the range of 20-45 A through a lidar transmitter circuit with a semiconductor laser and nonoptimized S-diode. The findings are consistent with the results of numerical simulation.

Gas Displacement Engineering Test by Combination of Low and Medium Pressure Injection with Liquid CO2 in High Gas and Low Permeability Coal Seam

Mining high-gas coal seams in China has the characteristics mining of deep, high storage and low permeability, and low drainage efficiency, which seriously restrict the efficient prevention and control of mine gas disasters. Based on the characteristics of low viscosity and permeability, phase change pressurization, and strong adsorption potential energy of liquid CO2, the technology system of liquid CO2 displacement for high-gas and low-permeability coal seam was developed, and field industrial of low-pressure (0.5~2.5 MPa) and medium-pressure (2.5~15.0 MPa) combined injection test was carried out. In this test, the mode of injection followed by drainage was adopted, and the gas drainage effect was investigated for 30 days. The test results show that the effective influence radius of CO2 in this test is 20 m, and the liquid seepage radius is 5 to 7 m. After the injection of liquid CO2 into coal seam, the average gas drainage concentration and drainage purity of all drainage holes were increased by 3.2 and 3.4 times, respectively, and the gas promotion effect was significant. Taking the liquid CO2 low-medium-pressure displacement gas test area as the calculation unit, from the comprehensive benefit analysis, compared with the original drainage mode, the liquid CO2-combined pressure injection process can save 34.7% of the engineering cost and shorten the gas drainage standard time by 45.9%. Therefore, the application of this technology has important technical support and reference significance for the efficient management of gas in the same type of mine.

Experimental Investigation of Polymer Enhanced Oil Recovery under Different Injection Modes.

To solve the problem of poor adaptability of the single slug polymer injection mode which lead to profile inversion, non-effective circulation of polymer solution in the high permeability zone during the development of conventional heavy oil, new technology of alternative injection, and three-stage slug injection for further improving polymer flooding performance were developed. Parallel sandpack flooding experiment was conducted to study the oil displacement efficiency of different injection modes, and reasonable injection mode and optimal slug combination of polymer flooding are selected. The results show that under the same polymer dosage, the high and low mass concentration polymer slug alternative injection is better than the three-stage slug and single slug polymer flooding, and with the increase of the alternating rounds, the polymer flooding performance increased first and then decreased. Compared with the single slug injection, the alternative injection increased the recovery factor by 4%. When the three-stage slug is injected, the concentration of the front and post slug has a significant effect on the oil displacement process. The optimal oil displacement formulations are as follows: main slug 5000 mg/L × 0.125 PV, secondary slug 3000 mg/L × 0.208 PV, alternating two rounds.

Numerical evaluation of pulverized coal swirling flames and NOx emissions in a coal-fired boiler: Effects of co- and counter-swirling flames and coal injection modes

A numerical evaluation was performed to investigate the effects of swirl arrangement (co-swirling and counter-swirling flows) and coal injection mode (non-, fully-, and partially-premixed with swirling flow) on the flame structure, coal particle uniformity, burnout performance, and nitrogen oxide (NOx) emissions in a 16-kWth coal-fired boiler. The co-swirling flame exhibits a tulip-shaped inner recirculation zone (IRZ), which increases the coal particle residence time: 1.61 s and 1.45 s for co-swirling and counter-swirling flames, respectively. In addition, the high uniformity of coal particles is maintained in all horizontal cross-sections. The total amount of NOx emissions at the boiler outlet are 205.0 and 551.2 ppm (@6% O2) for the co-swirling and counter-swirling flames, respectively; the deNOx efficiency is 62.8%. An exhaust tube vortex (ETV) structure with a tulip-shaped IRZ is observed in the non-premixed swirling flame injection mode; however, the ETV structure is not observed in the other injection modes. The ETV structure enhanced the coal particle uniformity and expanded the reaction zone, consequently reducing the area of the local high-temperature region. Although the non-premixed injection mode has a slightly lower burnout performance than other injection modes, it is determined to be more effective in reducing the total amount of NOx emissions.

Flow Injection Electrochemical Quartz Microbalance with ICP-OES Detection

The electrochemical quartz crystal microbalance (EQCM) has been previously reported in flow injection (FI) mode as a microgravimetric sensor for analytes that can be deposited onto an electrode surface through various mechanisms such as adsorption, covalent bond, or electrodeposition. Since this methodology does not provide the composition of the deposited species, it must be coupled with other analytical techniques.In this work, a new hyphenated technique, flow injection – electrochemical quartz crystal microbalance – inductively coupled plasma optical emission spectroscopy (FI-EQCM-ICP-OES), is used to study the deposition and stripping of metallic ions under hydrodynamic conditions in a modified commercially-available EQCM flow cell with a reaction volume of 50 uL. An automatic flow injection valve (FIV) delivers a fixed volume of analyte from a sample loop to the EQCM flow cell, where the electrodeposition reaction occurs, and the current and frequency change corresponding to the mass deposited on the electrode is measured in real time. After a film of the analyte has formed it can be rapidly stripped by changing the potential of the electrode. An ICP-OES connected downstream of the EQCM provides continuous elemental analysis throughout the deposition and stripping processes. One of the advantages is the possibility of sequential deposition-stripping experiments without having to disturb the working electrode in the flow cell.This platform was tested via flow injection of cupric sulfate samples in a sulfuric acid matrix at 200 uL/min, with cathodic electrodeposition and anodic stripping performed at different potentials. We also developed a finite element 3D model of the electrochemical flow cell in COMSOL Multiphysics®, with the simulated results in reasonable agreement to the measured current and mass deposition in the copper experiments. The image below shows the simulated [Cu+2] profile in COMSOL Multiphysics® during cathodic electrodeposition, 62 seconds after the sample enters the reaction chamber of the flow cell. Figure 1

Ignition, efficiency and emissions of RP-3 kerosene in a three-staged multi-injection combustor

In this work, a three-staged multi-injection based on the triple-swirler technique was proposed and investigated, which can broaden the engine envelope than a two-staged fuel supply scheme. The fuel can be split into three portions according to the combination of different injectors. Injection-1 means that only injector-1 supplies fuel, while Injection-1 + 2 means that injector-1 and injector-2 supply fuel simultaneously. The spark ignition performance, combustion efficiency, and exhaust emissions by using RP-3 kerosene are analyzed and compared with different fuel injection modes. The excellent ignition performance is achieved by using injection-1 with the ignition fuel-air ration is 0.008, whereas the other injection modes perform relatively poorly. The efficiency and exhaust emissions curves achieved by injection-1 + 2 and injection-1 + 3 intersect, where the overall equivalence ratio is about 0.25. When the overall equivalence ratio exceeds this critical value, the combustion efficiency of RP-3 kerosene achieved by using injection-1 + 3 can be up to 1% higher than injection-1 + 2. Furthermore, the optimal fuel supply scheme by the three-staged multi-injection technology is achieved: injection-1 is used for spark-ignition, injection-1 + 2 for low power conditions (overall equivalence ratio is less than 0.25), and injection-1 + 3 for high power conditions.

Pinning Control of Boolean Networks via Injection Mode

The pinning control of Boolean networks with both controls and injection modes is proposed. The system concerned is converted into a classical Boolean network with mix-valued logical controls. Under this framework three other fundamental control problems, including controllability, observability, and stabilization, are investigated.

Anomalous Transport in Three‐Dimensional Discrete Fracture Networks: Interplay Between Aperture Heterogeneity and Injection Modes

AbstractWe study how the interplay between fracture aperture heterogeneity and tracer injection mode controls fluid flow and tracer transport in three‐dimensional (3D) discrete fracture networks (DFNs). The direct 3‐D DFN simulations show that tracer injection mode has substantial effects on tracer spreading across all levels of aperture heterogeneity. The key controlling factor for effective transport is the initial Lagrangian velocity distribution, which is determined by the interplay between injection mode and aperture heterogeneity. The fundamental difference between initial Lagrangian velocity distribution and domain‐scale Eulerian velocity distribution plays a vital role in determining anomalous transport. We effectively capture the observed anomalous transport using an upscaled transport model that incorporates initial velocity distribution, stationary velocity distribution, velocity correlation length, and average advective tortuosity. With the upscaled transport model, we accurately capture the evolution of Lagrangian velocity distribution and predict longitudinal spreading in 3‐D DFN.

Patients' Perceptions and Preferences Regarding Two Different Forms of Methotrexate Autoinjectors for Moderate to Severe Rheumatoid Arthritis: A European Crossover Survey.

PurposeTreatment adherence is crucial in patients with rheumatoid arthritis (RA). The device used by the patients for self-injections may influence adherence to methotrexate (MTX) treatment. A MTX-autoinjector has been recently marketed in Europe. This crossover survey compared this MTX-autoinjector (MTX-autoinjector A) and an already existing MTX-autoinjector (MTX-autoinjector B) from the patients’ perspective.Patients and MethodsA total of 100 patients with moderate to severe RA using MTX-autoinjector A (N=35) or MTX-autoinjector B (N=65) were interviewed by an independent Global Market Research Company. Face-to-face interviews were performed using a computer-assisted personal interview system. Evaluation of the unfamiliar MTX-autoinjector was performed once the patients had received information, seen a demonstration, and performed a virtual testing.ResultsA substantial advantage in favor of the MTX-autoinjector A was found with respect to all surveyed indicators. Respectively, 95% and 55% of the users of MTX-autoinjectors A and B claimed to be very or totally satisfied with their familiar MTX-autoinjector. With respect to several specific characteristics, 91% and 60% of the users of MTX-autoinjectors A and B were very or totally satisfied with their familiar MTX-autoinjector, 29% and 77% found the unfamiliar MTX-autoinjector better, and 26% and 73% were interested in trying the unfamiliar MTX-autoinjector. Injection mode (with no push button) and end-of-injection recognition system (with audible signal) were identified as key features explaining a stronger preference for MTX-autoinjector A.ConclusionEven though deserving further studying, these findings are expected to guide clinicians when prescribing or renewing prescription of MTX-autoinjector, in particular in poor or non-compliant patients. In a context of growing interest in shared decision-making, the objective would be to choose with each patient the best suited MTX-autoinjector, and ultimately, to obtain a better treatment adherence.

The study of gas injection modes from a long tube to a channel filled with liquid

The results of experimental and numerical studies of the gas phase injection into the liquid column and sudden gas-liquid interaction are presented. Experimental study was performed by means of high-speed shadowgraph and analysis of signals of pressure transducers. The numerical part of the work was carried out using the OpenFOAM software. The data about void fraction distribution and pressure evolution are presented. In general, a good agreement between the experimental and calculated data was found. The data obtained can be used for verification and validation of different numerical codes, as example ones for the prediction of the process of the steam generation leakage on nuclear power plant.

Optimization Strategies for in Situ Groundwater Remediation by a Vertical Circulation Well Based on Particle‐Tracking and Node‐Dependent Finite Difference Methods

AbstractBoth theory and application of multispecies reactive transport for in situ groundwater bioremediation involving a vertical circulation well (VCW) are not fully understood despite its importance and common usage in aquifer remediation practices. This study proposes novel approaches including two methods for design and remediation prediction of a VCW system, which involves multispecies, multiphase, and microbially enhanced reactive transport process. One is particle‐tracking method, which depicts the trajectories of particles released from an injection chamber; the other is node‐dependent finite difference (NDFD) method, which describes the advection‐dispersion process based on the inflow and outflow directions at each node. The numerical results demonstrate that the particle‐tracking method works well by yielding a useful index, that is, the recovery ratio, which helps optimize the in situ preliminary remediation screening. When biochemical parameters, dispersivities, and in situ contaminated conditions are known after the preliminary screening, the NDFD method performs better than the conventional Laplace transform finite difference method in terms of describing multispecies reactive transport with multiple phases in a VCW system. The proposed particle‐tracking method and NDFD methods are employed to elucidate different effects of factors such as injection mode, hydraulic conductivity anisotropy ratio, distance between injection and extraction screened intervals, and injection/extraction rate on recovery and removal ratios. Our findings suggest that both methods are effective tools for optimization and prediction of VCW remediation in an anisotropic aquifer.

Biphasic CT imaging of deep neck infections (DNIs): how does dual injection mode helps in differentiation between types of collections?

BackgroundDeep neck infections are showing resurgence in the current era and still pose threatening diagnosis. CT is the gold standard imaging modality; still, the reported low sensitivity and specificity was suggested in view of monophasic injection technique.The purpose of the study was to discuss the diagnostic accuracy of CT with biphasic mode of injection using and a single scanning phase. The first 50–60 cc of IV contrast are injected at a slow rate of 1 cc/s to (tissue impregnation phase). The other 50–60 cc was injected at a high rate of 2 cc/sec, approximately 1 min after the first injection. The single phase of scanning is made followed by multi-planar image analysis of collection. Discrimination of abscess versus phlegmon is made according to described criteria.ResultsRadiological diagnosis was made of 64/66 cases of abscess and two cases only had phlegmon. The 64 cases of abscess underwent drainage by ENT surgeon showing correctly diagnosed drainable abscess in 59 out of 64 cases and 5 falsely diagnosed as abscess proved to be non-drainable phlegmon. The two patients with radiological diagnosis of non-drainable phlegmons were correctly diagnosed.ConclusionThe study achieved a high accuracy of 92%. This is likely attributed to dual-phase technique that allows enhancement of the core of a phlegmon by slow interstitial phase, while combined dual injections allow enhancing the “rim enhancement sign” of abscess.

Dual electrophoretically-mediated microanalysis in multiple injection mode for the simultaneous determination of acetylcholinesterase and α-glucosidase activity applied to selected polyphenols

Acetylcholinesterase (AChE) and α-glucosidase (α-glu) are key target enzymes in the search for novel strategies in the treatment of Alzheimer's disease and type II diabetes. Therefore, methods to assess the enzyme inhibition are of great value in the research field. Here is proposed a novel a dual electrophoretically-mediated microanalysis for the simultaneous determination of both enzymes' activity. In order to do so, the various solutions required for both assays were introduced in the capillary electrophoresis system using the multiple injections approach. Enzymatic kinetic parameters were tested, Km for AChE and α-glu were 3.81 and 0.43 mmol L−1. Ki values were 4.27 μmol L−1 for neostigmine (an AChE inhibitor) and 0.40 mmol L−1 for acarbose (an α-glu inhibitor). Results of IC50 (concentration for 50% of inhibition) were 5.11 ± 0.47 μmol L−1 and 0.58 ± 0,02 mmol L−1 for neostigmine and acarbose, respectively. All parameters (except for Ki of neostigmine) were comparable with the literature, indicating a good reliability of the proposed method to evaluate these enzymes activity. Total time analysis was approximately 10 min, being possible to perform around 12 enzymatic assays per hour, with low sample and reagent consumption, thus satisfying some of the principles of green chemistry. The method was applied to evaluate 10 phenolic compounds, of wich p-coumaric acid showed the best inhibitory activity for AChE (40.14 ± 4.75% at 10 mg L−1); and quercetin for α-glu (46.53 ± 4.90% at 10 mg L−1).

Polymeric Membrane Sensors for Batch and Flow Injection Potentiometric Determination of Procainamide

Three new potentiometric membrane sensors responsive to procainamide hydrochloride (PR) were constructed and their general performance characteristics were determined. The sensors were constructed from PR ion-association complexes with tetraphenylborate (NaTPB) (1), phosphomolybdic acid (PMA) (2) and phosphotungstic acid (PTA) (3) as exchange sites in a polyvinyl chloride (PVC) matrix. The sensors exhibited stable, rapid and near-Nernstian properties for PR at concentrations of $1\times 10^{{-2 }}$ – $4\times 10^{-6}$ , $1\times 10^{-2}- 5\times 10^{-6}$ , $1\times 10^{-2}$ – $6\times 10^{-6}$ M at 25 °C with cationic slopes of 58 ± 0.5, 57 ± 0.5 and 56 ± 0.5 (mV/decade) for sensor 1, 2 and 3 respectively. The response time of the sensors was 20s in the optimum pH range of 4-8. The sensors were used in steady state and flow injection mode (automated system). Method validation revealed the sensors have high selectivity, low detection limits, long life, wide dynamic ranges as well as high accuracy and precision. Direct determination of 5- $2000~\mu \text{g}$ /ml of PR in solution returned average recoveries of 98.5%, 99.0% and 98.5% and mean relative standard deviations of 1.6%, 1.6% and 1.8% at $200.0~\mu \text{g}$ /ml for sensor 1, 2 and 3 respectively. Further, detection of procainamide in spiked urine exhibited favorable relative standard deviation (1.60-1.76%) and high recovery (98.83-99.26%). The sensors were used as end-point indicators for titration of procainamide with NaTPB.

A periodic pumping technique of soil gas for 222Rn stabilization in large calibration chambers: part 2\u2014theoretical formulation and experimental validation

In an adjoining publication, we demonstrated the novel technique to harvest soil gas of natural origin as a highly efficient source of 222Rn for calibration applications in a large volume 222Rn calibration chamber. Its advantages over the use of conventional high strength 226Ra sources, such as the capability to serve as a non-depleting reservoir of 222Rn and achieve the desired concentration inside the calibration chamber within a very short time, devoid of radiation safety issues in source handling and licensing requirements from the regulatory authority, were discussed in detail. It was also demonstrated that stability in the 222Rn concentration in large calibration chambers could be achieved within ± 20% deviation from the desired value through a semi-dynamic mode of injection in which 222Rn laden air was periodically pumped to compensate for its loss due to leak and decay. The necessity of developing a theory for determining the appropriate periodicity of pumping was realized to get good temporal stability with a universally acceptable deviation of ≤ ± 10% in the 222Rn concentration. In this paper, we present a mathematical formulation to determine the injection periods (injection pump ON and OFF durations) for the semi-dynamic operation to achieve long term temporal stability in the 222Rn concentration in the chamber. These computed pumping parameters were then used to efficiently direct the injection of soil gas into the chamber. We present the mathematical formulation, and its experimental validations in a large volume calibration chamber (22 m3). With this, the temporal stability of 222Rn concentration in the chamber was achieved with a deviation of ~ 3% from the desired value.

Comparative study on effects of injection mode on combustion and emission characteristics of a combined injection n-butanol/gasoline SI engine with hydrogen direct injection

In this paper, on the basis of combined injection technique, three injection modes with five n-butanol/gasoline volume ratios (νN) were put forward, aiming to compare and evaluate the relationship between the injection mode and the combustion and emission characteristics of an n-butanol/gasoline SI engine equipped with an extra hydrogen direct injection system. The results indicated that under low load condition, compared with NGP (n-butanol/gasoline port injection) mode, the NGPD (n-butanol/gasoline combined injection) mode and NGPH (n-butanol/gasoline with hydrogen combined injection) mode can both improve the combustion performance. The peak cylinder pressure of NGPD and NGPH mode was 5.58% and 11.63% higher than that of NGP mode on average, respectively. Furthermore, the combined injection modes concentrated the process of heat release, shortened the combustion duration, increased the power performance and improved the combustion stability at all νN. As for emissions, the NGPD and NGPH combined modes significantly decreased the HC and CO emissions, but increased the NOX emissions. Among all the test conditions, the NGPH mode with 25% νN obtained the best combustion quality. Additionally, the effect rules of νN on combustion and emission characteristics under NGP mode were found to be consistent with those under NGPD and NGPH combined modes.