Injection Mode Research Articles

Near-infrared fluorescence imaging for sentinel lymph node identification in colon cancer: a prospective single-center study and systematic review with meta-analysis

BackgroundNear-infrared (NIR) fluorescence imaging has the potential to overcome the current drawbacks of sentinel lymph node mapping (SLNM) in colon cancer. Our aim was to provide an overview of current SLNM performance and of factors influencing successful sentinel lymph node (SLN) identification using NIR fluorescence imaging in colon cancer.MethodsA systematic review and meta-analysis was conducted to identify currently used methods and results. Additionally, we performed a single-center study using indocyanine green (ICG) as SLNM dye in colon cancer patients scheduled for a laparoscopic colectomy. SLNs were analyzed with conventional hematoxylin-and-eosin staining and additionally with serial sectioning and immunohistochemistry (extended histopathological assessment). A true-positive procedure was defined as a tumor-positive SLN either by conventional hematoxylin-and-eosin staining or by extended histopathological assessment, independently of regional lymph node status. SLN procedures were determined to be true negatives if SLNs and regional lymph nodes revealed no metastases after conventional and advanced histopathology. SLN procedures yielding tumor-negative SLNs in combination with tumor-positive regional lymph nodes were classified as false negatives. Sensitivity, negative predictive value and detection rate were calculated.ResultsThis systematic review and meta-analysis included 8 studies describing 227 SLN procedures. A pooled sensitivity of 0.63 (95% CI 0.51–0.74), negative predictive value 0.81 (95% CI 0.73–0.86) and detection rate of 0.94 (95% CI 0.85–0.97) were found. Upstaging as a result of extended histopathological assessment was 0.15 (95% CI 0.07–0.25). In our single-center study, we included 30 patients. Five false-negative SLNs were identified, resulting in a sensitivity of 44% and negative predictive value of 80%, with a detection rate of 89.7%. Eight patients had lymph node metastases, in three cases detected after extended pathological assessment, resulting in an upstaging of 13% (3 of 23 patients with negative nodes by conventional hematoxylin and eosin staining).ConclusionsSeveral anatomical and technical difficulties make SLNM with NIR fluorescence imaging in colon cancer particularly challenging when compared to other types of cancer. As a consequence, reports of SLNM accuracy vary widely. Future studies should try to standardize the SLNM procedure and focus on early-stage colon tumors, validation of tracer composition, injection mode and improvement of real-time optical guidance.

Cluster ion source for external injection and high capacity filling of light elements into the relativistic heavy ion collider electron beam ion source.

An advanced Electron Beam Ion Source (EBIS) is the primary ion source to supply highly charged ion beams of different elements to the Relativistic Heavy Ion Collider (RHIC) and to the NASA Space Radiation Laboratory (NSRL). Intense beams of highly charged ions of various elements of the periodic table, ranging from helium to uranium, have been demonstrated since EBIS became operational in 2010. EBIS routinely provides ion beams to RHIC and NSRL quasisimultaneously with about 1 s switching time between different ion species. Such unique flexibility and rapid switching between ion species are based on external injection of singly charged ions into the EBIS trap either in "fast" or "slow" injection modes. At present, a Laser Ion Source (LIS) provides most of the ion species of solid materials using the "fast" injection mode into the EBIS trap and a Hollow Cathode Ion Source (HCIS) provides most of the ion species of gaseous elements using the "slow" injection mode into the EBIS trap. Gas injection into the EBIS trap is also possible and has been used but imposes some restrictions for the simultaneous generation of highly charged ions such as Au32+ ions for RHIC and ions of gaseous species for NSRL. Because light ions have relatively high velocity inside the EBIS trap, efficient injection of hydrogen and helium ions and filling of the EBIS trap to high capacity is difficult from either LIS or HCIS. To overcome this restriction and enhance EBIS operational capability, we suggest injecting beams of hydrogen and helium cluster ions into the EBIS trap. Required parameters of cluster ion beam injection into the EBIS trap are estimated, and advantages of such an injection are highlighted. A cluster ion source with required high intensity is visible and will be designed, built, optimized, and tested.

Study of Rain Simulation for Aircraft Engine Certification

Engine tests under flight conditions are extremely important at the stage of its complex debugging. These conditions include the simulation of icing, check for the penetration of birds in the inlet vanes, modeling hail and rain. Simulation of rain due to its significant unsteadiness need providing requirements for the concentration of water in the air, the distribution spectrum of droplets by size, the value of the average diameter of the droplets, the mass flow rate curves for the injectors and the conditions of interaction of droplets with air. This paper contains information about the developed method of calculating the characteristics of the injector for the necessary modes of water injection into the engine as well as experimental study of the injector and conducted studies of the parameters of its operation process, including the choice of optimal modes. As a result of the research, an injector was developed that allows to obtain the average median diameter of 2.66 mm and droplets of the certification spectrum. Also there was worked out the schematic diagram of the collector module of the installation for rain simulation that meets the certification requirements: simulation of rain in the “idle power” and “take-off” modes with the condition of simultaneous provision of water concentration in the air of 20 g/m3 and the average median diameter of 2.66 mm. This installation provides operation in transient modes with the condition of maintaining the water concentration in the air of 20 g/m3.

Fabrication of Metal Matrix Composite by Laser Metal Deposition-A New Process Approach by Direct Dry Injection of Nanopowders.

Laser Metal Deposition (LMD) offers new perspectives for the fabrication of metal matrix nanocomposites (MMnCs). Current methods to produce MMnCs by LMD systematically involve the premixing of the nanopowders and the micropowders or require in-situ strategies, thereby restricting the possibilities to adjust the nature, content and location of the nano-reinforcement during printing. The objective of this study is to overcome such restrictions and propose a new process approach by direct injection of nanoparticles into a metallic matrix. Alumina (n-Al2O3) nanoparticles were introduced into a titanium matrix by using two different direct dry injection modes in order to locally increase the hardness. Energy dispersive X-ray spectroscopy (EDS) analyses validate the successful incorporation of the n-Al2O3 at chosen locations. Optical and high resolution transmission electron microscopic (HR-TEM) observations as well as X-ray diffraction (XRD) analyses indicate that n-Al2O3 powders are partly or totally dissolved into the Ti melted pool leading to the in-situ formation of a composite consisting of fine α2 lamellar microstructure within a Ti matrix and a solid solution with oxygen. Mechanical tests show a significant increase in hardness with the increase of injected n-Al2O3 amount. A maximum of 620 HV was measured that is almost 4 times higher than the pure LMD-printed Ti structure.

Dye Tracking Following Posterior Semicircular Canal or Round Window Membrane Injections Suggests a Role for the Cochlea Aqueduct in Modulating Distribution.

The inner ear houses the sensory epithelium responsible for vestibular and auditory function. The sensory epithelia are driven by pressure and vibration of the fluid filled structures in which they are embedded so that understanding the homeostatic mechanisms regulating fluid dynamics within these structures is critical to understanding function at the systems level. Additionally, there is a growing need for drug delivery to the inner ear for preventive and restorative treatments to the pathologies associated with hearing and balance dysfunction. We compare drug delivery to neonatal and adult inner ear by injection into the posterior semicircular canal (PSCC) or through the round window membrane (RWM). PSCC injections produced higher levels of dye delivery within the cochlea than did RWM injections. Neonatal PSCC injections produced a gradient in dye distribution; however, adult distributions were relatively uniform. RWM injections resulted in an early base to apex gradient that became more uniform over time, post injection. RWM injections lead to higher levels of dye distributions in the brain, likely demonstrating that injections can traverse the cochlea aqueduct. We hypothesize the relative position of the cochlear aqueduct between injection site and cochlea is instrumental in dictating dye distribution within the cochlea. Dye distribution is further compounded by the ability of some chemicals to cross inner ear membranes accessing the blood supply as demonstrated by the rapid distribution of gentamicin-conjugated Texas red (GTTR) throughout the body. These data allow for a direct evaluation of injection mode and age to compare strengths and weaknesses of the two approaches.

Investigation on trajectories and capture of magnetic drug carrier nanoparticles after injection into a direct vessel

Toxic effects of drugs on healthy tissues in the traditional way of chemotherapy are considered as the serious challenges of cancer treatment. Magnetic drug targeting is a method that can be used for topical treatment of cancerous tumors as well as to reduce the side effects of drugs. In this paper, a finite element simulation is carried out to calculate the trajectories and capture of drug carrying Fe3O4 magnetic nanoparticles under the influence of an external magnetic field. Two different cases of uniform distribution of the nanoparticles in the blood flow, and a separate injection in the vein are considered and the effects of different parameters such as blood velocity, magnetic field intensity, and particle diameter on the capture efficiency are investigated. Results show that injection of magnetic nanoparticles in an appropriate site can be very effective in blood vessels with high blood flow velocities. The capture efficiency of the particles in a separate injection mode is shown to be improved up to 85% in comparison with the case of uniform flow of the particles in the blood vessel. However, it is indicated that the drug targeting is not successful when the injection site is located opposite to the permanent magnet. Moreover, it is observed that the capture efficiency of the drug carrying particles depends on the magnitude of the magnetic and drag forces. The capture efficiency increases with increase of the magnetic field intensity and particles diameter and decrease with the blood flow velocity.

Initial Transfer Behavior and Solidification Structure Evolution in a Large Continuously Cast Bloom with a Combination of Nozzle Injection Mode and M-EMS

A three-dimensional numerical model combining electromagnetic field, fluid flow, heat transfer, and solidification has been established to study the effect of nozzle injection mode and mold electromagnetic stirring (M-EMS) on the internal quality of a continuously cast bloom. The model is validated by measured data of the magnetic flux density along the stirrer center line. According to the simulation and experimental results, M-EMS can introduce a horizontal swirling flow ahead of the solidification front, promoting the superheat dissipation of molten steel and columnar to equiaxed transition (CET). As the stirring current increases from 0 to 800 A, the superheat at the mold exit in the bloom center decreases by 1.9 K for the single-port nozzle case and 3.8 K for the five-port nozzle case. The resulting increase in the equiaxed crystal ratio is about 5.65% and 4.06%, respectively. In comparison, the injection mode shows a more significant influence on the heat transfer and solidification structure in the bloom under the present casting conditions. The superheat at the mold exit in the bloom center decreases by 5.1–7.7 K as the injection mode changes from a single-port nozzle to a five-port nozzle, and the increase in the equiaxed crystal ratio ranges between 14.8% and 17%. It is found that the flow velocity of the molten steel in front of the solidification interface for the five-port nozzle is higher than that for the single-port nozzle regardless of the M-EMS power. The washing effect here reinforces both the heat exchange through the solidification interface and the dendrite re-melting or fragmenting, stimulating the formation of an equiaxed crystal at the bloom center. In addition, it is observed that both the central shrinkage and carbon segregation have decreased with the five-port nozzle plus M-EMS. This suggests that the combined application of a five-port nozzle and M-EMS can effectively improve the internal quality of large bloom castings.

Experimental study on recharge capacity of a mixed well injection in Xi’an

The over-exploitation of groundwater can be controlled and prevented by using mixed well to recharge groundwater. A seepage model of semi-confined aquifers was established for simulating recharge well in a cone of depression. Two mathematical expression formulas were proposed for estimating recharge capacity. To analyze the response of recharge capacity, stepwise injections were introduced. It can be pointed out that recharge capacity increases with that of injection flow; moreover, it tends to attenuate during steady injection, which is closely related to injection flow. An attenuation equation of recharge capacity was constructed finally. Recharge capacity was not related to injection mode. The results indicate that under similar conditions, recharge capacity of a mixed well was about one-third of pumping capacity. A minimum value of recharge capacity was maintained with constant injection. Mixed wells were used to recharge and recover groundwater from the cone of depression.

Influence of flame stabilization and fuel injection modes on the flow and combustion characteristics of gas turbine combustor with cavity

The power-weight ratio is an important feature of a gas turbine used in transportation applications. However, while the ultra-compact combustion mode shows good application prospects, achieving high-efficiency and low-resistance combustion in an ultra-compact space at high air velocities remains a major challenge. A new ultra-compact combustion mode was proposed in this paper to further increase the configurable compactness with improvements to the flow and combustion characteristics. The relationships of the flow and combustion characteristics with the combustor configuration were numerically investigated in detail, and the calculation model was verified experimentally. This study focused on the configurable factors of the combustor components related to the major combustion zone, including the mainstream flame holder, the radial cavity, the fuel injector, and the diffusion channel. The results showed that rapid fuel-air blending and high-efficiency combustion were achieved under the condition of an ultra-compact space and a high air injection velocity. The adoption of a streamlined flame holder with a radial cavity and the integration of a simple fuel injector with a flame holder were very effective at simultaneously improving the configurable compactness and combustion characteristics without increasing the flow resistance, and these achievements are significant for improving the power-weight ratio of gas turbines.

A nanoelectrode array for obtaining intracellular recordings from thousands of connected neurons

Current electrophysiological or optical techniques cannot reliably perform simultaneous intracellular recordings from more than a few tens of neurons. Here, we report a nanoelectrode array that can simultaneously obtain intracellular recordings from thousands of connected mammalian neurons in vitro. The array consists of 4,096 platinum-black electrodes with nanoscale roughness fabricated on top of a silicon chip that monolithically integrates 4,096 microscale amplifiers, configurable into pseudo-current-clamp mode (for concurrent current injection and voltage recording) or into pseudo-voltage-clamp mode (for concurrent voltage application and current recording). We used the array in pseudo-voltage-clamp mode to measure the effects of drugs on ion-channel currents. In pseudo-current-clamp mode, the array recorded intracellular action potentials and post-synaptic potentials from over thousands of neurons. In addition, we mapped over 300 excitatory and inhibitory synaptic connections from over 1,700 neurons that were recorded for 19 mins. This high-throughput intracellular-recording technology could benefit functional connectome mapping, electrophysiological screening, and other functional interrogations of neuronal networks.

Cadmium Assisted Photochemical Vapor Generation of Tungsten for Detection by Inductively Coupled Plasma Mass Spectrometry.

Efficient photochemical vapor generation (PVG) of tungsten has been achieved for the first time using a 19 W thin film flow-through photoreactor. The volatile product (most probably tungsten hexacarbonyl) was generated using a flow injection mode and 40% (v/v) formic acid as the reaction medium. An inductively coupled plasma mass spectrometer was utilized for ultrasensitive detection. The addition of Cd2+ as a sensitizer was critical, enhancing the overall PVG efficiency some 30 000-fold. At an optimal irradiation time of 19 s, a 6.1-fold enhancement factor and an overall PVG efficiency of 43% were determined from a comparison of the response to direct solution nebulization when using a sample flow rate of 2 mL min-1 and 500 mg L-1 Cd2+ as a sensitizer. A limit of detection of 0.9 ng L-1 and repeatability (RSD) of 2% at 100 ng L-1 were achieved. Interference from inorganic acids (HNO3, HCl, H2SO4, and HF) was investigated with respect to analytical application to real samples. The accuracy and practical feasibility of this ultrasensitive methodology was successfully verified by analysis of Certified Reference Material CTA-FFA-1 (Fine Fly Ash) and six natural water samples with low W concentrations.

Productivity and solvent waste in supercritical fluid chromatography for preparative chiral separations: a guide for a convenient strategy

The advent of supercritical fluid chromatography (SFC) in the 90s has changed preparative liquid chromatography. SFC is an improved way for separating chiral compounds during drug discovery processes yielding upwards of one hundred grams of pure enantiomers or during clinical trials requiring higher quantities.The need to purify approximately 45 mg of racemic mixture raises concerns regarding processing parameters, including injection volumes and frequency, column size, chromatographic method, and feed composition. In this study, Chiralpak® AD-H amylose tris(3,5-dimethylphenylcarbamate) polysaccharide-based stationary phase columns of various dimensions were investigated for the purification of propranolol using EtOH (+0.3% triethylamine)/CO2 15/85 v/v as the mobile phase. Production rate (mg/h), productivity (kilograms of racemate separated per kilogram of chiral stationary phase per day; kkd), solvent usage (L/g) and environmental factor (E Factor) were calculated for four column sizes for sequence and stacked modes of injection. The parameters were optimized to determine a method yielding high productivity or reduced environmental impact.In the stacked mode of injection, which allows for rapid processing compared with the sequential mode, the shortest column presents the best productivity of 0.176 kkd. A semi-preparative column (30 mm i.d.) yielded the best production rate of 467 mg purified per hour but had the worst environmental impact with an E Factor of approximately 56,414 (due to the solvent volume used during column equilibration). At Column Dilution (ACD) and mixed stream injection mode were also compared to separate 495 mg of propranolol. With ACD injection, 915 mL of ethanol and approximately 48 min were required, whereas with mixed stream injection, 1200 mL of ethanol and 63 min were required.

Technological Characteristics of Injection Molding of Dynamic Elastoplasts Based on Thermoplastic Polyolefins and Butyl Rubber

The influence of the butyl rubber concentration and technological mode of injection molding on the main properties of elastoplasts based on butyl rubber and thermoplastic polyolefins—low-density polyethylene and polypropylene—was considered. Initially, the influence of the butyl rubber concentration on the ultimate tensile stress, tensile stress at yield, and elongation at break of the polymer mixtures based on low-density polyethylene and polypropylene was investigated. It was found that, with the concentration of butyl rubber in the composition based on low-density polyethylene equal to 20 wt % or higher and in the composition of polypropylene equal to 40 wt % or higher, the compositions change the deformation mechanism, i.e., the transition of plastic deformation into highly elastic deformation characteristic of rubbers occurs. The use of dicumyl peroxide and sulfur as crosslinking agents made it possible to obtain dynamically vulcanized elastoplasts with improved physicomechanical and technological properties during the “monotrem” process. The original design of the worm screw on the injection molding machine of the brand DE3132.250Ts1 makes it possible to carry out on it a “monotrem” technology of obtaining elastoplastic and dynamic vulcanizates on their basis. This technology allows in a single cycle of injection molding simultaneously to implement in the material cylinder the mixing of thermoplastic and elastomeric components in the melt, followed by their vulcanization with dicumyl peroxide or sulfur to form dynamically vulcanized elastoplasts. During the investigation the technology of mechanochemical synthesis of initial polymer mixtures and dynamic elastoplasts, the influence of the temperature regime of injection molding on the cylinder zones, the injection molding pressure, the mold temperature, and the injection boost time on their ultimate tensile stress, elongation at break, and volume contraction was established. A detailed interpretation of the observed regularities in the change in the properties of composite materials was given.

Phenomenological Model of Radiation Hardness of LEDs Based on AlGaInP Heterostructures with Multiple Quantum Wells

Neutron degradation of LEDs based upon AlGaInP heterostructures (λ=630 nm and λ=590 nm) with multiple quantum wells are presented in the article. For the initial red LED (λ=630 nm) we can clearly distinguish three characteristic regions. In the small current region a low electron injection mode into the active region of the LEDs is observed. Further, as the operating current goes up, there are average and high electron injection in the active LEDs area regions. However, for the LEDY, the difference in the average and high electron injection regions is more pronounced and low electron injection region is absent. The boundary between the average and high electron injection regions can be characterized by the boundary current, which goes up with increasing exposure level. Three regions of electron injection in the active area of LEDs: low, average and high electron injection are illustrated for both types of LEDs under fast neutron irradiation. Based on the established relationships describing the emission power changing, a phenomenological model of the radiation hardness of LEDs based on AlGaInP heterostructures with MQW was shown. The LEDs radiation hardness is determined by the boundary current value, emission power in the low electron injection into the active LEDs area, the initial defective structure.

Comparative study about oxidation of trace N-nitrosamines by seven oxidation processes with a sensitivity improved determination method

N-nitrosamines are highly toxic disinfection byproducts (DBPs) formed in drinking water treatment process. Moreover, they could permeate reverse osmosis (RO) membrane during water recycling. Herein, an improved detection method for simultaneously determining 9 N-nitrosamines was established, and 7 kinds of oxidation processes were examined for degradation of the 9 N-nitrosamines. Compared with conventional injection mode, pulsed injection technique improved signal to noise ratio (SNR) and peak area of N-nitrosodimethylamine (NDMA) by 2.1 and 3.77 times, respectively. Low method detection limits (MDLs) were achieved ranging from 0.3 to 1.5 ng/L. Based on the improved detection method, simultaneous oxidation of 9 N-nitrosamines with UV irradiation/UV based advanced oxidation processes (AOPs), O3/O3 based AOP, and permanganate and ferrate were comparatively investigated. Among these employed processes, O3/H2O2 was the most effective approach for the elimination of N-nitrosamines, and 36.6% (NDMA)-91.4% (NDBA) removal efficiency was achieved. In comparison, ozonation merely removed less than 20% of N-nitrosamines (except NDphA for 29.3%). Compared to UV irradiation, the removal efficiency of N-nitrosamines was improved by almost 10% in UV/Cl2 process, while the improvement in UV/peroxydisulfate (UV/PDS) process was not obvious. Permanganate and ferrate oxidations on N-nitrosamines removal were not significant. NDMA was found to be one of the most recalcitrant N-nitrosamines, therefore, it could be monitored as an indicator of N-nitrosamines in relevant treatment process. Finally, the risk of N-nitrosamines re-formation was found to be negligible when chloramination was applied after oxidation treatment.

Etched glass micromodel for laboratory simulation of NAPL recovery mechanisms by surfactant solutions in fractured rock

Fractured porous media receive less attention than classic porous media in terms of remediation processes and sui` techniques that can be applied efficiently. An etched glass micromodel was built in order to simulate a fractured bedrock. The purpose of this paper was to evaluate the feasibility of surfactant-alcohol injection to recover NAPL with this fractured glass micromodel. The influence of several parameters influencing NAPL recovery via surfactant injection were tested in the micromodel: the ratio of alcohol to surfactant, the total concentration of active matter (alcohol + surfactant), the number of pore volume injected, the direction of the injection, and the continuous or pulsed injection mode. These tests made it possible to identify the key parameters for a better recovery of NAPL in a fractured environment, which are: continuous upward injection, six pore volume of surfactant solution and a n-AmOH/n-BuOH ratio of 2.5. Micromodel experiments were compared to previous reported experiments using the same surfactant solutions injected in classical porous media. The lower capillary number being required for NAPL recovery in porous media is probably related to the better sweep and the increase in surface area available for NAPL dissolution. NAPL recovery may be improved by increasing the capillary number by increasing the injected surfactant solution viscosity with polymer or by injecting foam.

Comparison of Triggered Explosion Behavior by Corium Injection Modes in TROI Facility

In the postulated severe accidents of nuclear power plants, the interaction mode of the molten corium with water happens differently depending on the height of the water level in the reactor cavity. The interaction of the molten corium with the partially filled water in the reactor cavity has been extensively studied. The molten corium in this case was released into the water after free falling to some distance. Meanwhile, some advanced reactors have adapted the in-vessel corium retention concept by cooling the reactor vessel’s outside wall. If a reactor vessel failure happens in this case, the molten corium in the reactor vessel is injected directly into the water without any free fall. Triggered steam explosion experiments were carried out to compare the explosion behavior conditions of the partially flooded cavity and ex-vessel cooling. It was found that the jet breakup process before the explosion appeared differently between the two experiments. These behaviors contributed to the differences in the maximum dynamic pressure and load that express the explosion’s strength. The explosion’s strength under the partially flooded cavity condition was about two times stronger than that under ex-vessel cooling. Accordingly, it is believed that the steam explosions under conditions of ex-vessel cooling are of less concern than the partially flooded cavity condition.

A comparative study on effects of homogeneous or stratified hydrogen on combustion and emissions of a gasoline/hydrogen SI engine

A comparative study on effects of homogeneous or stratified hydrogen on combustion and emissions was presented for a gasoline/hydrogen SI engine. Three kinds of injection modes (gasoline, gasoline plus homogeneous hydrogen and gasoline plus stratified hydrogen) and five excess air ratios were applied at low speed and low load on a dual fuel SI engine with hydrogen direct injection (HDI) and gasoline port injection. The results showed that, with the increase of excess air ratio, the brake thermal efficiency increases firstly then decreases and reaches the highest when the excess air ratio is 1.1. In comparison with pure gasoline, hydrogen addition can make the ignition stable and speed up combustion rate to improve the brake thermal efficiency especially under lean burn condition. Furthermore, it can reduce the CO and HC emissions because of more complete combustion, but produce more NOX emissions due to the higher combustion temperature. Since, in the gasoline plus stratified hydrogen mode, the hydrogen concentration near the sparking plug is denser than that of homogeneous hydrogen, the ignition is more stable and faster, which further speed up the combustion rate and improve the brake thermal efficiency. In the gasoline plus stratified hydrogen mode, the brake thermal efficiency increases by 0.55%, the flame development duration decreases by 1.0°CA, rapid combustion duration decreases by 1.3°CA and the coefficient of variation (COV) decreases by 9.8% on average than that of homogeneous hydrogen. However, in the gasoline plus stratified hydrogen mode, due to the denser hydrogen concentration near the sparking plug and leaner hydrogen concentration near the wall, the combustion temperature and the wall quenching distance increase, which make the NOX and HC emissions increase by 14.3% and 12.8% on average than that of homogeneous hydrogen.

Bonding mechanism of explosive compaction–welding sintering

Correlation theories of explosive compaction–welding sintering are introduced, and a method for calculating the pressure required for explosive compaction–welding is provided. A macroscopic bonding mechanism study involving a flying-plate loading experiment reveals that the incident angle of a shockwave plays an important role in explosive compaction–welding, and the propagation law of shockwaves in powder layers is numerically analyzed using the AUTODYN-2D software. In the microscopic bonding mechanism study, the microscopic bonding modes of explosive compaction–welding are investigated with a Cu wire coating and Cu substrate. The smoothed-particle hydrodynamics numerical simulation method is used to simulate the void-closure process between the Cu wire and Cu substrate under specific pressures. By comparing the results of the numerical simulation and experiment, the micro-bonding modes of friction welding, explosive welding, jet injection, and liquid sintering are determined. The effect of diffusion sintering is studied, and the poor bonding areas are eliminated after diffusion sintering. The element diffusion between the coating and substrate is observed to ensure the existence of diffusion welding.

Direct high sensitive determination of elements in gasoline, kerosene, and mineral oil solutions by inductively coupled plasma atomic emission spectrometry (ICP-AES)

Direct ICP-AES analysis of petroleum products, organic solvents and fuels is oftentimes possible only in the mode of radial plasma viewing and requires the use of special sample injection systems, the design of which depends significantly on the physical properties of the sample, in particular, on its volatility and viscosity. Volatile oil fractions and products (naphtha, gasoline), as well as and heavy and viscous oil fractions of and petroleum products (vacuum gas oil, fuel oil, thick lubricating oils) are the most problematic objects of analysis. We consider the possibility of direct analysis of the samples based on gasoline, kerosene and lubricating oils dissolved in kerosene using inductively coupled plasma atomic emission spectrometry (ICP-AES). The possibility of using various configurations of sample injection systems and modes of plasma viewing of vertically located torch for direct analysis of the samples based on kerosene and gasoline is considered. A significant improvement in the sensitivity of determination of the elements in gasoline and kerosene using an axial plasma viewing combined with optimal configurations of sample introduction systems and plasma burning modes is demonstrated.