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During the COVID-19 pandemic, there was heightened concern about the sudden spread of viral diseases. As the threat of coronavirus transmission began to diminish, a subsequent outbreak caused by monkeypox virus (MPXV) emerged in Europe and North America. Notably, MPXV infection tends to be transmitted through sexual contact, increasing the difficulty of tracing the infection route through passive testing. As a result, there is a pressing need for cost-effective, precise, and rapid on-site screening techniques to detect MPXV. Recently, the CRISPR system, known as a genome editing tool, has been used as a rapid on-site diagnostic tool for detecting nucleic acids mostly through the use of Cas12a and Cas13a. Intriguingly, deficient Cas9 (dCas9) can recognize specific double-stranded DNA (dsDNA) sequences and bind to complementary DNA sequences. Here, we devised an innovative digital field-diagnosis platform that can be readily employed in clinical settings. This platform combines an ultrasensitive field-effect transistor (FET) with the dCas9 system, enabling quantitative analysis of biomarkers. Our dCas9-EG-FET can directly detect viral dsDNA without any amplification or pretreatment. When the dCas9 of our dCas9-EG-FET system recognizes the specific target viral DNA, the EG-FET system provides voltage differences by using FET features that measure the ion concentration on the surface of the FET sensor. Furthermore, it takes only 20 min to detect MPXV DNA using our dCas9-EG-FET system at room temperature (RT), and this system can be used to effectively distinguish single-point mutations with high sensitivity. Our findings suggest that the use of a CRISPR Cas-based biosensor could lead to an effective strategy for screening for infectious diseases. • A rapid on-site nucleic acid detection for MPXV was implemented using FET and dCas9. • Detection is completed within 20 min at RT without amplification or pre-treatment. • Accurate enough to distinguish single nucleotide differences. • A small amount of target DNA can be specifically detected in an among other DNAs. • EG system made of PDMS is useful for multiple samples and easy-to-use in the field. [ABSTRACT FROM AUTHOR]

In this study, the effect of intake manifold geometry on cylinder-to-cylinder variation was investigated considering the volumetric efficiency, early tumble development, turbulent kinetic energy, and spark plug gap velocity using computational fluid dynamic program, CONVERGE v2.4. The simulation model was validated based on the PIV experiment in the cylinder and Mie-scattering experiment of intake manifold, and its results agreed well with the experiment results. The curved intake manifold and straight manifold were compared. As a result, it was advantageous for cylinder-to-cylinder variation in the straight intake manifold compared to the curved intake manifold in perspective of volumetric efficiency which were a maximum deviation of 1.7% in curved manifold and 0.6% in straight manifold. And the straight manifold had an effect of the strengthening the in-cylinder flow, so that the turbulent kinetic energy near TDC was increased to maximum 11% than curved manifold. And considering the effect of manifold curve radius on in-cylinder flow intensity in straight manifold, with increasing engine speed, the in-cylinder flow intensified during compression with decreasing the intake manifold radius due to the short distance between manifold inlet and port. Especially at 2000 rpm, the tumble ratio increased 55% at intake manifold radius of 10 cm than of 7 cm at bTDC 280 deg. Therefore, for the purpose of enhancing the in-cylinder flow near spark plug timing, shortened distance between intake manifold inlet and port and increasing the manifold radius is required. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of fuel properties on the spray characteristics of a common-rail type marine diesel injector. Spray characteristics are highly influential in determining engine performance and emission characteristics in direct-injection engine systems containing marine diesel engines. Thus, the relationship between the physical properties of HFO fuel and its spray characteristics is investigated via an analysis of HFO and spray experiments. Data from physical property measurements (e.g., fuel density, dynamic viscosity, and surface tension) are used to derive empirical equations between fuel temperatures and physical properties, and the results follow the common tendencies of temperature–property curves for general liquid substances. In spray experiments, injection quantity measurements, injection rate profiles, and spray visualization were conducted under various injection pressures, energizing durations, and ambient pressures. The test temperatures of HFO were set from the results of physical property measurements. Experimental data reveal that spray characteristics are affected by fuel properties in terms of injection delays, injection profiles, and spray development speed. The injection quantity increased proportionally with fuel densities and the onset of injection was delayed with increased dynamic viscosity. Spray tip penetration decreased with increased fuel temperature. [ABSTRACT FROM AUTHOR]

• Visualization of in-cylinder flow and flame using an optically accessible engine. • Characteristics of in-cylinder flow and flame in the catalyst-heating mode. • Effects of intake valve timing and duration on tumble and flame propagation speed. • Investigation of the amount of residual gas depending on exhaust valve timings. The effects of intake and exhaust valve timing and duration were investigated using an optically accessible multi-point injection engine under catalytic heating conditions. The target engine features a quartz cylinder and an extended piston with a quartz piston crown. To understand the effects of valve timing and duration on the in-cylinder flow, particle image velocimetry (PIV) was applied to visualize the in-cylinder flow. The acquired images were used to quantitatively evaluate the in-cylinder flow characteristics, and the effects of these flow characteristics on the flame propagation were analyzed through flame visualization experiments. The results indicate that when the intake valve timing was advanced by 20°, the average flow velocity was 59.5% higher, the tumble ratio was 72.2% greater, and the flame propagation velocity was also the fastest. The longest duration of 218° was advantageous for the intake valve duration, and the formation of a tumble flow pattern was important for fuel and air mixing. Finally, in the exhaust valve timing and duration experiment, the exhaust valve closing timing affected the amount of residual gas inside the cylinder. Therefore, the ratio of diffusion flames increased when the exhaust valve timing was advanced or retarded compared to the reference exhaust valve timing. [ABSTRACT FROM AUTHOR]

This study investigated the cycle-to-cycle variation of a spark-assist high-compression-ratio spray-guided direct-injection two-cylinder optically accessible engine. The cycle-to-cycle variation was evaluated by calculating the mean velocity, tumble ratio, tumble center, and effective radius using the PIV measurement results. Under all experimental conditions, the mean velocity continuously decreased owing to the momentum loss from the intake to compression strokes. A low COV was observed within the high-velocity region, and the effective radius decreased as rotational flow formed regardless of the engine operating conditions. As the engine speed increased, owing to the high piston speed, the in-cylinder flow intensified. However, the effective radius and tumble ratio were similar during the compression stroke. As the intake pressure increased from 0.8 to 1.3 bar, the mean velocity and tumble ratio slightly increased. Moreover, the effective radius decreased slightly during the compression stroke. As the IVO timing was retarded, during the intake stroke, the structure of the in-cylinder flow changed dramatically. Rapid momentum dissipation occurred after the intake air inflowed strongly, resulting in relatively weak rotational flow compared to the reference and advanced IVO timing conditions. • Visualization of the in-cylinder flow in high-pressure spray-guided DI engine. • Investigation of cycle-to-cycle variation depending on engine operating parameters. • Influences of fuel injection on cycle-to-cycle variation and in-cylinder flow. • The cycle-to-cycle variation of in-cylinder flow decreased as the fuel was injected. [ABSTRACT FROM AUTHOR]

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO2) than port fuel injection (PFI) engines when fossil fuel conditions are the same. However, GDI engines emit more ultrafine particulate matter, which can have negative health effects, leading to particulate emission regulations. To satisfy these regulations, various studies have been done to reduce particulate matter, and several studies focused on lubricants. This study focuses on the influence of lubricant on the formation of particulate matter and its effect on particulate emissions in GDI engines. An instrumented, combustion and optical singe-cylinder GDI engine fueled by four different lubricant-gasoline blends was used with various injection conditions. Combustion experiments were used to determine combustion characteristics, and gaseous emissions indicated that the lubricant did not influence mixture homogeneity but had an impact on unburned fuels. Optical experiments showed that the lubricant did not influence spray but did influence wall film formation during the injection period, which is a major factor affecting particulate matter generation. Particulate emissions indicated that lubricant included in the wall film significantly affected PN emissions depending on injection conditions. Additionally, the wall film influenced by the lubricant affected the overall particle size and its distribution. [ABSTRACT FROM AUTHOR]

• Flash boiling phenomena was reviewed from fundamental to applications. • Superheated degree is an important factor that effects spray behavior under flash boiling conditions. • Nozzle configuration is another factor that effects the spray behavior under flash boiling conditions. • Under high superheat conditions, spray is immediately vaporized after being injected from the nozzle. The flash boiling phenomenon occurs when the ambient pressure around fuel is lower than the saturation pressure. This is followed by the formation and growth of bubbles. Flash boiling has been regarded as a promising method to improve the atomization of fuel sprays and to reduce emissions without a high-pressure injection system, which has recently become a popular topic. Therefore, it is necessary to summarize the current research status of flash boiling sprays. This review seeks to provide on overall understanding of flash boiling sprays in gasoline direct injection (GDI) injectors and includes theoretical, experimental, and numerical studies relevant to the flash boiling process. The effects of the degree of superheating and injector configuration, which includes the spacing angle, nozzle number and nozzle length, on spray behavior under flash boiling conditions are analyzed. Furthermore, in order to gain a deep understanding of the collapse mechanism of the spray, the formation of the collapse is explained from several aspects, including the velocity field, temperature field, vapor concentration field, and droplet diameter. A thorough understanding of flash boiling spray behaviors and the collapse mechanisms can help further technological applications, such as injector design and injection strategies. Finally, an overview of the available theoretical models and their applications is presented, which provides a simple and concise method of understanding flash boiling spray behavior. [ABSTRACT FROM AUTHOR]

• Effects of spray behavior on the particle number emissions were studied. • Sprays are affected by the in-cylinder flow significantly at higher injection pressure. • Higher injection pressure promotes the interaction between fuel and cylinder wall. • Particle emissions increase with higher pressure injection at late injection timing. The effects of injection pressure on spray behaviors governing particulate matter emissions were investigated for various injection timings and engine loads in an optically accessible single cylinder engine equipped with gasoline direct injection system. In a spray visualization and particle number (PN) measurement experiment, injection timing and engine load were varied to examine their effects on the spray behavior including cylinder wetting that causes the emission of particulate matter. The analysis was based on the time-averaged spray images, spray variations between the cycles, combustion, and PN emission characteristics. The spray structure in the cylinder under the engine operating conditions used in the present study was a collapsed spray that was evident at high pressure injection under atmospheric conditions. For an injection timing of before top death center (BTDC) 300 deg, at the initial stage of the intake process, the magnitude of spray deflection formed by the in-cylinder flow interacting with the spray in the reverse direction increased owing to the high pressure injection promoting fuel atomization and increasing the effects of the in-cylinder flow. The spray variations between the cycles caused by the in-cylinder flow in the region of spray deflection were also increased by high pressure injection. When the weak in-cylinder flow was formed in the late intake process (BTDC 210 deg), increasing the injection pressure accelerated the initial droplet velocity and increased the amount of fuel reaching the cylinder wall opposite the injector, thus increasing the wall film and PN emissions. In contrast, for the conditions under which the wall film was formed on the piston top by fuel interaction, the large droplet momentum corresponding to high pressure injection increased in the amount of rebounded droplets at collision, thereby reducing the amount of wall film and PN emissions. [ABSTRACT FROM AUTHOR]

The effects of exhaust load and injection timing on particle emission and combustion characteristics were investigated using a single-cylinder gasoline engine equipped with a direct injection system. Particulate matter emission was counted by PPS-M, and the cylinder pressure was measured to analyze the combustion phasing. An exhaust valve was installed to simulate an exhaust load caused by a gasoline particulate filter, and the exhaust load between the exhaust port and after-treatment system was varied with increasing exhaust pressure from 0.1 bar to 0.4 bar as a gauge pressure. Injection timing was swept from BTDC 330 deg to BTDC 210 deg during the intake process to enhance the homogeneity of the mixture. The main source of particulate matter at an early injection timing (i.e., BTDC 330 deg) is the fuel film on top of the piston. In addition, the homogeneity of the fuel/air mixture is the most important factor for particle number emission for the late injection case. In-cylinder temperature increased during fuel injection, and the fuel/air mixture became more homogeneous due to the increased internal EGR caused by the exhaust load. As a result, the experimental result showed that a maximum 75% reduction of particle number emission in early injection was achieved by increasing exhaust load from 0.1 bar to 0.4 bar in gauge pressure. [ABSTRACT FROM AUTHOR]

• The GDI engine system with multi-hole type injector is reviewed. • The current status on GDI engine studies is provided. • Spray/atomization and combustion/emission characteristics of GDI engine was reviewed. Given diminishing fossil fuel resources and severe environmental pollution, governments are strengthening their regulations regarding the exhaust emissions and fuel consumption of transportation vehicles. To satisfy the new stringent requirements for emission and efficiency, researchers have attempted to combine the advantages of gasoline and diesel engines in a single engine. Studies on gasoline direct -injection (GDI) engines have been conducted since the early 1990s. In a GDI engine, the fuel is directly injected into the combustion chamber to form a stratified air/fuel mixture for ultra-lean combustion. To achieve the proper mixture in the combustion chamber of a GDI engine, various injection and airflow strategies have been implemented, such as the multiple-injection and spray-guided techniques. In addition, various emission after-treatment devices, such as a gasoline particulate filter and lean NO x trap have been used to reduce exhaust emissions. Major injector manufacturers recently embarked on the development of a piezo-outwardly type injector and a multi-hole type injector to improve engine performance and reduce exhaust emissions. In addition, researches are actively pursuing alternative fuels, such as bioethanol and biobutanol, eco-friendly alcohol fuels, for use in GDI engines. In this review article, we examine and discuss the GDI engine system. Our objective in the review is to examine the injection, spray, combustion, and exhaust emission characteristics of a GDI engine with a multi-hole injector. We also review numerical methods for modeling a GDI engine and describe the characteristics that make alcohol fuels useable in GDI engines. [ABSTRACT FROM AUTHOR]

This work has numerically analyzed the structure of spray flames with various ambient oxygen concentrations. To realistically predict the spray evaporation characteristics in the high-pressure diesel-like environment, the present study has employed the high-pressure effective conductivity vaporization model. The detailed n-heptane/air chemistry is represented by 114 elementary steps and 44 chemical species. The Representative Interactive Flamelet (RIF) model is adopted to consider the interactions between turbulence and chemistry in the fast transient reacting flows. In order to account for the spatial inhomogeneity of the scalar dissipation rate, the multiple RIFs are introduced. Moreover, the present approach realistically models the vaporization effects on the mixture fraction fluctuations. For the various conditions of ambient oxygen concentration, numerical results are compared with experimental data including the ignition delay and the lift-off length. These results indicate that the present MRIF approach yields the reasonably good agreement with experimental data in terms of ignition delay time and lift-off length. To gain the physical insight into the two-stage ignition behavior of diesel fuels, the detailed discussions are also made for the temporal evolution of several key species (CH2O, OH, CO) mass fraction and maximum temperature of the transient flamelet as well as the flame stabilization mechanism of the n-heptane spray flames with the much lower ambient oxygen concentration. [ABSTRACT FROM AUTHOR]

Abstract The present study investigated the effect of coolant temperature, injection pressure, and injection timing on emissions in a gasoline direct injection (GDI) engine. Two coolant temperatures of 40 °C and 80 °C, and wide range of injection timings from before top dead center (BTDC) 360° to BTDC 210° were tested under injection pressures in the range of 5 MPa–50 MPa. Particle number (PN), soot, total hydrocarbon (THC), and nitrogen oxides (NOx) were measured under the various experimental conditions. In addition, the spray and flame images were used to observe the spray-wall interaction and to identify the existence of a fuel film. Experimental results showed that the increase in injection pressure significantly reduced the particulate emissions, especially for the wall wetting condition (BTDC 330°). The PN emissions from the wall wetting condition was reduced by about 90% by increasing injection pressure from 10 MPa to 50 MPa. Furthermore, increasing the coolant temperature was an effective way to reduce the PN, soot, and THC. In particular, the THC was reduced by about 30%, while the change in injection pressure and injection timing varied by only 10%. Highlights • Effects of high injection pressure (up to 50 MPa) and coolant temperature on PN emissions were analyzed. • We achieved 90% reduction in PN emissions by applying 50 MPa injection pressure from 10 MPa. • Increased coolant temperature contributed to decrease PN, soot, and THC emissions. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate possible improvements in ICEVs by implementing fuzzy logic-based parallel hard-type power hybrid systems. Two types of conventional ICEVs (gasoline and diesel) and two types of HEVs (gasoline-electric, diesel electric) were generated using vehicle and powertrain simulation tools and a Matlab-Simulink application programming interface. For gasoline and gasoline-electric HEV vehicles, the prediction accuracy for four types of LDV models was validated by conducting comparative analysis with the chassis dynamometer and OBD test data. The predicted results show strong correlation with the test data. The operating points of internal combustion engines and electric motors are well controlled in the high efficiency region and battery SOC was well controlled within ± 1.6%. However, for diesel vehicles, we generated virtual diesel-electric HEV vehicle because there is no available vehicles with similar engine and vehicle specifications with ICE vehicle. Using a fuzzy logic-based parallel hybrid system in conventional ICEVs demonstrated that HEVs showed superior performance in terms of fuel consumption and CO 2 emission in most driving modes. [ABSTRACT FROM AUTHOR]

Helical fins including the downward (−30°), flat (0°), and upward (15°, 30°, 45°) fins were applied to the inner wall of a high temperature steam generator (HTSG) in the same direction as superheated steam flowing in the HTSG, to improve heat transfer performance. The flow inside the HTSG and the temperature change were analyzed using numerical analysis. Without a fin, the numerical analysis results showed a difference of up to 11.6% for superheated steam and 5.1% for hot gas compared with the actual experimental temperature readings. When steam was introduced into the HTSG, a secondary vortex flow was generated around it, along with a descending swirl flow and the application of helical fins inhibited downward flow and increased the time that the steam received heat from the superheater. In addition, the upward type fin prevented the escape of the superheated steam from the upper surface of the fin better than the downward type fin, in which the curved surface of the fin faces downward of the HTSG. The secondary flow occurred between the HTSG wall and the fins, which contributed to the improved of heat transfer. The highest temperature of steam discharge was at an upward fin angle of 15°. • Helical fins were applied to the inner wall of a high temperature steam generator. • Flow and temperature characteristics were analyzed using numerical investigation. • The downward (−30°), flat (0°), and upward (15°, 30°, 45°) fins were evaluated. • The highest temperature of steam discharge was at an upward fin angle of 15°. [ABSTRACT FROM AUTHOR]

There is an urgent need for detailed comparative engine performance assessment of alternative fuels such as biofuels vis-à-vis conventional gasoline and diesel. Single cylinder genset engines are widely used in developing countries in very large numbers in agriculture and decentralized power generation sectors, therefore such a detailed understanding becomes even more important. In this study, the effects of change in fuel on noise, vibrations, and engine combustion characteristics of a single cylinder genset engine are investigated. Three different test fuels; mineral diesel, Jatropha biodiesel (JB100), and Jatropha biodiesel-diesel blend (JB20) were used. Spray characterization studies were also conducted and it was found that the spray penetration length, and spray cone angle are strongly influenced by ambient pressure for all the three test fuels. These parameters are not significantly different, especially at higher ambient pressures (1 MPa, and 2 MPa) for different test fuels. The study shows that the variation of HRR max and combustion duration for test fuels correlates well with our measurements of combustion noise and vibrations. A higher value of HRR max corresponds to higher levels of combustion noise. [ABSTRACT FROM AUTHOR]

Main objective of this study was to demonstrate endoscopic visualization of combustion events in the combustion chamber of a production grade compression ignition (CI) engine. High speed endoscopic imaging was used to provide qualitative information about the in–cylinder combustion for mineral diesel and biodiesel fueled engine operating at different engine loads. These images were analyzed using image processing program developed in MATLAB, in order to determine the ‘start of combustion’ (SoC), ‘spatial soot distribution’ and ‘spatial flame temperature distribution’. In–cylinder pressure and rate of heat release (RoHR) were validated using simulation results obtained by using a KIVA-3V code. The luminosity of flames in the combustion images was relatively lower for biodiesel compared to baseline diesel. Area of soot distribution decreased in later stages of combustion for both test fuels, which indicated superior oxidation of soot particles formed, during the post combustion events. Biodiesel showed relatively lower dissipation of heat, which caused lower soot radiations in the flames. Simulated soot distribution and flame temperature distribution obtained from KIVA-3V code also showed similar behavior and verified the trends observed by combustion chamber endoscopy. [ABSTRACT FROM AUTHOR]

The macroscopic spray characteristics and internal structure of a highly expanded compressed natural gas (Methane; CH 4) spray were experimentally and numerically investigated. The spray jet characteristics were analyzed under various pressure ratios (PR), defined as the ratio of the methane injection pressure to the ambient pressure. The spray characteristics and shockwave structures were investigated using Schlieren imaging. The novelty originates from comparing the methane spray development and shockwave parameters under low PR (4 < PR < 9) conditions. The investigation included an evaluation of the effect of choking phenomena on gas flow at different PRs by changing the methane injection pressure. The results showed that a high injection pressure did not improve the spray tip penetration but increased the choking phenomenon in methane flow in the near-field region. This phenomenon is a key factor that strongly influences the shockwave structure and leads to 3.5% longer injection duration and at least 13% increase in the spray volume and area before entering the fully developed region of the Mach disk. With respect to the Mach disk parameters, a PR change from 6 to 9 enhanced the Mack disk height by at least 13.5% and its width by at least 29%. Increasing the Mach disk width with PR increased the methane near-field angle of the spray by at least 29%, triple-point angle by at least 29%, and spray width at the triple point by at least 29% because of the larger radial gas spray development. Overall, the comparison of the macroscopic spray characteristics and Mach disk parameters showed that the macroscopic spray parameters were almost similar despite the changes in the PRs. In contrast, the Mach disk parameters (height, width, and triple point angle) and variations in the methane spray field were larger than those in the macroscopic spray parameters. In addition, the simulation results were used to analyze the energy conservation and transfer conversion efficiencies of the gaseous injection system. The same increase in PR led to greater energy transfer and conversion efficiencies by 0.05% and 6.7%, respectively, which adversely affects charge mixing in the intake manifold. Strong air turbulence is required to enhance the charge-mixing mechanism and achieve a homogeneous fuel-air mixture. Therefore, the choking phenomenon requires more attention when implementing gaseous injection systems for internal combustion engines. • Macroscopic of shock wave methane spray is obtained and its internal structure is found. • Energy conversion and energy transfer efficiencies with accuracy less than 48.5% and 30.7%. • Choked flow is most affected to the injection duration by the low pressure ratio conditions. [ABSTRACT FROM AUTHOR]

Among the new combustion technologies available for internal combustion engines to enhance performance and reduce exhausted emissions, the homogeneous charge compression ignition method is one of the most effective strategies for the compression-ignition engine. There are some challenges to realize the homogeneous charge compression ignition method in the compression-ignition engine. The use of gasoline–diesel blended fuel has been suggested as an alternative strategy to take advantages of homogeneous charge compression ignition while overcoming its challenges. Gasoline and diesel fuels are reference fuels for the spark-ignition and compression-ignition engines, respectively, both of which are widely used. The application of both these fuels together in the compression-ignition engine has been investigated using a hybrid injection system combining port fuel injection (gasoline) and direct injection (diesel); this strategy is termed reactivity controlled compression ignition. However, the pre-blending of gasoline and diesel fuels for direct injection systems has been rarely studied. For the case of direct injection of pre-blended fuel into the cylinder, various aspects of blended fuels should be investigated, including their spray breakup, fuel/air mixing, combustion development, and emissions. In the present study, the use of gasoline–diesel pre-blended fuel in an optical single-cylinder compression-ignition engine was investigated under various conditions of injection timing and pressure. Furthermore, KIVA-3V release 2 code was employed to model the formation of fuel/air mixtures in the cylinder. Neat diesel fuel was tested, as well as gasoline–diesel blends of 20% and 40% gasoline mass fraction. Experiments on the mixed fuels showed that the inclusion of gasoline fuel improved fuel/air mixing, yielding more homogeneous mixtures over wider cylinder areas. The low cetane index of gasoline fuel induced long ignition delays in the mixed fuels. Compared with neat diesel combustion flame, blended fuel did not produce the soot flame, white-yellow flame. Soot intensity was calculated based on captured flame images, and its variations were investigated as a function of fuel type and injection conditions. [ABSTRACT FROM AUTHOR]

The present study investigates the effect of the injection strategy on the mixture quality and the consequential combustion characteristics. The injection strategies considered in the present study were divided into two parts: single injection (with a wide range of injection timings during the intake stroke) and double injection (with a short second injection during the compression stroke). The in-cylinder pressure and high-speed flame images were acquired to evaluate the combustion characteristics, and KIVA simulation was conducted to observe the in-cylinder flow and the fuel spray spreading procedure. For the single injection, retarding the injection timing caused an increase in the combustion speed and in-cylinder pressure. In this case, the major factor that increased the in-cylinder pressure was the turbulence intensity; the later injection produced a stronger turbulence at the spark timing, which caused a higher in-cylinder pressure. Meanwhile, the flame propagation direction was mainly affected by the equivalence ratio distribution. The flame speed toward the fuel-lean region was significantly slower than toward the fuel-rich region. The double injection strategy utilized the additional turbulence induced by the spray motion to increase the engine power. [ABSTRACT FROM AUTHOR]

• Effects of needle behavior on fuel flow rate of GDI injectors were analyzed. • The movement of armature and ball was quantitatively analyzed through the X-ray visualization. • Flow rate of the second injection gradually increased as dwell time was shortened. To meet strong emission regulations such as Euro-7, which is expected to be implemented in 2025. The multiple-injection strategy is one of well-known solutions to reduce exhaust gas and improve combustion performance on GDI engine. In order to realize multiple-injection strategy, it is necessary to secure excellent flow rate repeatability within short period. Therefore, the purpose of this study was to analyze the flow rate repeatability of GDI injector under various multiple injection conditions and to correlate with needle behavior of GDI injector and flow rate repeatability. To analyze flow rate repeatability, the injection rate data was obtained by the Bosch method and the individual flow rates of 110 shots were analyzed under several experimental conditions. The movements of the ball and armature inside the injector were visualized using the X-ray phase contrast imaging (XPCI) technique, and the individual behaviors of the ball and the armature were quantitatively analyzed by image post-processing analysis. In this study were used two test GDI injectors with same structure. Whereas Flow rate results were different on shorter dwell time conditions. This study revealed that a specific injector had unstable injection rate and worse Shot to Shot (STS) deviation under dwell time 0.7 ms. In addition, armature bouncing appeared in a specific GDI injector. This armature bouncing affects unstable flow rate characteristics because when armature lift up again, the position of armature was different at every time. [ABSTRACT FROM AUTHOR]

• In-cylinder flow was enhanced using only injection strategy. • Tumble was enhanced with horizontal injection in gasoline direct injection engine. • The velocity near the spark plug was enhanced with horizontal injection. • Stratification near the spark plug can be achieved by horizontal injection. In a direct-injection gasoline engine, combustion instability can increase because of the formation of an inhomogeneous mixture under stoichiometric conditions, a slow combustion rate under lean conditions, and misfires. Effective methods of dealing with combustion instability include enhancing tumble, increasing turbulence intensity, and enhancing stratification, and increasing flow velocity near the spark plug. Many studies have been conducted to enhance in-cylinder flows, but they have been limited to geometry modification or multi-injection. In this study, we adopt a horizontal injection strategy, as opposed to simple multiple injection in previous studies, to enhance in-cylinder flows. We examine the effect of horizontal injection on tumble by using a horizontal injector with an upward spray pattern and computational fluid dynamics. The tumble ratio and turbulence kinetic energy of the horizontal injector are compared to those of a conventional injector, which has a downward spray pattern. In addition, the effects of double injection on stratification and velocity near the spark plug at the end of compression are compared to that under single injection in terms of the equivalence ratio and average velocity near the spark plug. An injection pressure of 35 MPa is utilized. The total mass injected is 30 mg, and it is split into masses of 27 mg and 3 mg when using double injection. The CONVERGE v2.4 software application is used to reduce computational costs. The spray model is validated through a Schlieren visualization of the pent-roof combustion chamber, in which a high-temperature and high-pressure environment are simulated. The results indicate that horizontal injection enhances the tumble ratio and turbulence intensity by 22% and 26%, respectively, compared to those achieved with conventional, downward-spray injection. While double injection fails to enhance the tumble ratio and turbulence kinetic energy because the second injection mass is small, the velocity and stratification near the spark plug at the end of the compression strike are enhanced from −2 and 13.8 m/s to 11.5 and 18.6 m/s, respectively, because of double injection. [ABSTRACT FROM AUTHOR]

In this investigation, effect of 10%, 20% and 50% Karanja biodiesel blends on injection rate, atomization, engine performance, emissions and combustion characteristics of common rail direct injection (CRDI) type fuel injection system were evaluated in a single cylinder research engine at 300, 500, 750 and 1000 bar fuel injection pressures at different start of injection timings and constant engine speed of 1500 rpm. The duration of fuel injection slightly decreased with increasing blend ratio of biodiesel (Karanja Oil Methyl Ester: KOME) and significantly decreased with increasing fuel injection pressure. The injection rate profile and Sauter mean diameter ( D 32 ) of the fuel droplets are influenced by the injection pressure. Increasing fuel injection pressure generally improves the thermal efficiency of the test fuels. Sauter mean diameter ( D 32 ) and arithmetic mean diameter ( D 10 ) decreased with decreasing Karanja biodiesel content in the blend and significantly increased for higher blends due to relatively higher fuel density and viscosity. Maximum thermal efficiency was observed at the same injection timing for biodiesel blends and mineral diesel. Lower Karanja biodiesel blends (up to 20%) showed lower brake specific hydrocarbon (BSHC) and carbon monoxide (BSCO) emissions in comparison to mineral diesel. For lower Karanja biodiesel blends, combustion duration was shorter than mineral diesel however at higher fuel injection pressures, combustion duration of 50% blend was longer than mineral diesel. Up to 10% Karanja biodiesel blends in a CRDI engines improves brake thermal efficiency and reduces emissions, without any requirement of hardware changes or ECU recalibration. [ABSTRACT FROM AUTHOR]

• The injection quantity and injection rate increased as the fuel density increased. • The spray penetration was longer in the order of LPG fuels > gasoline > n-heptane. • The nozzle tip wetting was wider in the order of LPG fuels > n-heptane > gasoline. Unlike the conventional liquid phase LPG injection (LPLI) system, an LPG direct injection (LPDI) system directly injects fuel into the combustion chamber, so the temperature inside the combustion chamber decreases due to the latent heat of vaporization of the fuel. Therefore, the direct injection (DI) system has the advantage of increasing fuel efficiency and power performance. However, a classic problem of the DI system is that a large amount of particle numbers (PNs) is emitted due to the nozzle tip wetting, which is affected by the spray characteristics related to the fuel properties. Therefore, research on nozzle tip wetting using an LPDI injector is needed. The purpose of this study is to investigate the macroscopic spray characteristics of four test fuels: n-heptane, gasoline, LPG winter, and LPG summer, using Mie scattering visualization, Schlieren visualization, and nozzle tip wetting using a long-distance microscope (LDM). The experiments were conducted using a three-hole LPDI injector with a step hole. In the comparison of n-heptane, gasoline, and the LPG fuels, the vapor pressure of the test fuels was high, in the order of LPG winter > LPG summer > gasoline > n-heptane. In addition, the surface tension of the test fuels was low, in the order of LPG winter < LPG summer < n-heptane < gasoline. The results revealed that the spray penetration of the LPG fuels was longer than that of n-heptane and gasoline because of flash boiling. Also, by comparing the nozzle tip wetting of these fuels, the wet area was wider in the order of LPG winter > LPG summer > n-heptane > gasoline. [ABSTRACT FROM AUTHOR]

• Visualization of the in-cylinder flow and spray structure in spray-guided DI engine. • Investigation of the interaction between in-cylinder flow and spray structure. • Numerical analysis of the mixture formation depending on injection timing. • The mixture formation can be divided as homogeneous, stratified and mal distribution depending on injection timing. In this study, a spray-guided gasoline direct-injection 2-cylinder optically accessible engine was used to analyze the characteristics of the in-cylinder flow and mixture formation using PIV measurements and computational fluid dynamics (CFD; CONVERGE v2.4). The mean velocity, tumble ratio, turbulent kinetic energy, and tumble center were calculated to quantify the characteristics of the in-cylinder flow. Moreover, flow rotation intensity was defined to evaluate the in-cylinder flow depending on the crank angle. In the early stage of the intake stroke, the intake air flowed into the cylinder with high momentum and velocity. Subsequently, tumble flow was generated in the middle stage of the intake stroke, and weak in-cylinder flow occurred during the compression stroke owing to the dissipation of momentum. The fuel injection caused intensification of the in-cylinder flow, increasing the in-cylinder flow velocity, tumble ratio, and turbulent kinetic energy. Furthermore, mixture formation was affected by the end of the injection timing and its characteristics were classified into homogeneous, stratified, and mal-distribution mixtures, depending on the region to which the end of injection timing belonged. [ABSTRACT FROM AUTHOR]

Hybrid electric vehicle (HEV) tend to emit large amount of gaseous and particle emissions right after engine restart (ER). In this study, on-board particulate number (PN) measurement test and chassis dynamometer tests were conducted to analyze the effects of the ER combustion strategy on the gaseous and particle emission characteristics of a gasoline direct injection (GDI) HEV. The on-board PN measurement tests were conducted to examine the effect of a parameter sweep such as injection pressure, end of injection (EOI), spark timing of ER. It was measured by the pegasor particle sensor (PPS)-M, a device that measures the number of particles with a size from 23 nm to 25 μm, and the ES-582.1 module that can acquire electronic control unit (ECU) data. In the chassis dynamometer test, particle emissions, gaseous emissions and fuel economy of the reference case and the Combination Case 2 were compared and analyzed in the worldwide harmonized light vehicles test cycles (WLTC) mode test using Horiba, MEXA-ONE and MEXA-2000 solid particle counting system (SPCS). Reference case refers to a control strategy that does not touch anything in the vehicle's basic control strategy, and Combination Case 2 is the largest PN reduction case combined by calibrating the parameters. On-board PN measurement tests show that in reference case, ER PN accounted for about 70% of the total PN. Compared to the reference case, the sum of ER PN averages tended to decrease with higher injection pressure, advanced EOI, and retarded spark timing. The results of Combination Case 2 indicate that the sum of ER PN averages decreased by 88.7% compared to the reference case. In the WLTC mode test, THC, CO emissions and fuel economy were almost the same, and NOx was reduced by 85.6%. In both PPS and SPCS, the sum of ER PN average ratios decreased by 20%. • Effect of emissions according to the parameter sweep for the GDI HEV was studied. • RDE and chassis dynamometer test were conducted. • Engine restart results in a lot of PN emissions. • A significant amount of PN was reduced through the combination of control strategies. [ABSTRACT FROM AUTHOR]

In a gas turbine combustion system, droplet distribution in the combustor directly affects the combustion process. Fuel droplet size and droplet velocity determine the fuel droplet distribution in the combustor. The present study aims to investigate effects of physical properties on spray characteristics using computational fluid dynamics (CFD) analysis. Spray modeling was performed to analyze the spray characteristics for different fuel physical properties. The hollow cone spray of a gas turbine nozzle was modeled using a LISA (Linearized Instability Sheet Atomization)-TAB(Taylor Analogy Breakup) model with commercial CFD code called, ANSYS Fluent 16.2. The model was validated against the experimental results, which were obtained by PDPA (Phase Doppler Particle Analyzer) and spray tomography. Based on this spray model, the effect of fuel physical properties on spray characteristics were determined. In addition, because the spray patterns differed various injection fluids, the spray characteristics of the gas turbine nozzle with various injection fluids were considered from the perspective of fuel physical properties. It was found that higher density, viscosity and surface tension delayed the atomization process and that density and surface tension have a more significant effect on spray atomization, than viscosity in the catastrophic breakup regime. • Physical properties of fuels affect spray characteristics significantly in both development processes and SMD distributions. • Spray behaviors for various fuel have been modeled successfully using CFD. • Effects of fuel density on spray behavior are more influential than those of viscosity and surface tension. • Density ratio between the fuel and ambient air is the most important factor in size distributions. [ABSTRACT FROM AUTHOR]

In this study, the particle emission characteristics of gasoline vehicles with four different types of spark ignition engines, i.e., port fuel-injection (PFI), 150-bar side-mounted gasoline direct-injection (GDI), 200-bar side-mounted GDI, and 200-bar center-mounted GDI vehicles, were evaluated using Federal Test Procedure-75 (FTP-75) and worldwide harmonized light vehicles test cycle (WLTC). Particulate matter (PM), particle number (PN), and organic carbon/elemental carbon ratio (OC/EC) were evaluated using a PM holder, a solid particle counting system, and an OC/EC analyzer. The results of the PM and PN emissions tests indicated that GDI 200-bar vehicles emitted less than GDI 150-bar vehicles, and center-mounted vehicles emitted less than side-mounted vehicles. PFI vehicles showed 15% higher PN emission rates compared with GDI vehicles during acceleration conditions in FTP-75 mode. Additionally, PN emissions in WLTC hot mode indicated that speed affects PFI vehicles more than GDI vehicles. Furthermore, PFI vehicles did not show significant PN emissions in a low-speed phase, even at high acceleration. PFI vehicles showed 15% higher PN emission rates compared with GDI vehicles while accelerating in FTP-75 mode. PFI and GDI side-mounted vehicles showed higher OC emission rates in hot mode than in cold mode. • Effects of four different gasoline vehicles on particle emission were studied. • High-pressure injection reduces PM and PN emissions. • During acceleration, PFI vehicle showed higher PN emission rate than GDI vehicles. • PFI, GDI side mount vehicles OC/EC emissions were affected by engine warm-up. [ABSTRACT FROM AUTHOR]

• Coupled investigation using an optical single cylinder and KIVA code was performed. • Flame intensities are dependent on the combustion timing and diffusion combustion. • Wall heat transfer was calculated based on the KIVA code. This paper describes the effects of swirl flow in a diesel optical single-cylinder engine with experimental results and simulation results obtained using KIVA code. Experiments were conducted with an optical single-cylinder engine for various operating conditions such as injection timing, exhaust gas recirculation (EGR), and swirl ratio, and a numerical study was also conducted to analyze the effects of swirl flow and combustion characteristics in detail. Correlations between in-cylinder flow from numerical simulations and the flame propagation process from experiments were conducted. The optical experimental and simulation results demonstrated that retarded injection timing and high EGR rate reduced the luminosity of flame and the wall heat transfer. However, a high EGR rate simultaneously reduced the combustion efficiency. The average luminosity of the optical image was determined by the flame in the high-temperature region above 2400 K. The luminosity and volume fraction of the temperature region above 2400 K showed the same trends. Correlation results between the experiment and simulation showed that swirl flow affects the propagation process. The flame region was generated in the center of the combustion chamber due to swirl flow based on visualization and analysis results. That is, swirl flow caused separation of the flame by disrupting the continuity of the spray. [ABSTRACT FROM AUTHOR]

Prostate Imaging Reporting and Data System (PI-RADS) score, a reporting system of prostate MRI cases, has become a standard prostate cancer (PCa) screening method due to exceptional diagnosis performance. However, PI-RADS 3 lesions are an unmet medical need because PI-RADS provides diagnosis accuracy of only 30-40% at most, accompanied by a high false-positive rate. Here, we propose an explainable artificial intelligence (XAI) based PCa screening system integrating a highly sensitive dual-gate field-effect transistor (DGFET) based multi-marker biosensor for ambiguous lesions identification. This system produces interpretable results by analyzing sensing patterns of three urinary exosomal biomarkers, providing a possibility of an evidence-based prediction from clinicians. In our results, XAI-based PCa screening system showed a high accuracy with an AUC of 0.93 using 102 blinded samples with the non-invasive method. Remarkably, the PCa diagnosis accuracy of patients with PI-RADS 3 was more than twice that of conventional PI-RADS scoring. Our system also provided a reasonable explanation of its decision that TMEM256 biomarker is the leading factor for screening those with PI-RADS 3. Our study implies that XAI can facilitate informed decisions, guided by insights into the significance of visualized multi-biomarkers and clinical factors. The XAI-based sensor system can assist healthcare professionals in providing practical and evidence-based PCa diagnoses., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose: Reduced fibrinogen levels are associated with worse outcomes in bleeding trauma patients. The purpose of this study was to evaluate the potential of the prehospital shock index (SI) and its derivatives, the age shock index (aSI) and the modified shock index (mSI), as predictors of hypofibrinogenaemia in trauma patients., Methods: This retrospective study included 2383 patients who presented to a regional trauma center. We reviewed the plasma fibrinogen levels upon admission to the trauma center and patients were divided into two groups: the hypofibrinogenaemia group and the normal group. The predictive performances of the SI, aSI, and mSI were assessed by the area under the receiver operating characteristic curve (AUC)., Results: Of the 2383 patients, 235 (9.9%) had hypofibrinogenaemia. Patients with hypofibrinogenaemia were more likely to receive transfusions within 4 h and had significantly greater in-hospital mortality than patients with normal fibrinogen levels. The AUCs of prehospital SI, prehospital aSI, and prehospital mSI for the prediction of hypofibrinogenaemia were 0.75 (95% confidence interval [CI] 0.73-0.77), 0.70 (95% CI 0.68-0.72), and 0.75 (95% CI 0.73-0.77), respectively., Conclusion: Prehospital SI and prehospital mSI demonstrated moderate performance for identifying trauma patients with hypofibrinogenaemia. The prehospital aSI had poor predictive performance. In the prehospital setting, the use of prehospital SI or prehospital mSI as the sole predictor of hypofibrinogenaemia in trauma patients is not recommended., (© 2024. The Author(s).)

Cervical length (CL) measurement using transvaginal ultrasound is an effective screening tool to assess the risk of preterm birth. An adequate assessment of CL is crucial, however, manual sonographic CL measurement is highly operator-dependent and cumbersome. Therefore, a reliable and reproducible automatic method for CL measurement is in high demand to reduce inter-rater variability and improve workflow. Despite the increasing use of artificial intelligence techniques in ultrasound, applying deep learning (DL) to analyze ultrasound images of the cervix remains a challenge due to low signal-to-noise ratios and difficulties in capturing the cervical canal, which appears as a thin line and with extremely low contrast against the surrounding tissues. To address these challenges, we have developed CL-Net, a novel DL network that incorporates expert anatomical knowledge to identify the cervix, similar to the approach taken by clinicians. CL-Net captures anatomical features related to CL measurement, facilitating the identification of the cervical canal. It then identifies the cervical canal and automatically provides reproducible and reliable CL measurements. CL-Net achieved a success rate of 95.5% in recognizing the cervical canal, comparable to that of human experts (96.4%). Furthermore, the differences between the CL measurements of CL-Net and ground truth were considerably smaller than those made by non-experts and were comparable to those made by experts (median 1.36 mm, IQR 0.87-2.82 mm, range 0.06-6.95 mm for straight cervix; median 1.31 mm, IQR 0.61-2.65 mm, range 0.01-8.18 mm for curved one).

The average-speed emission model (Speed-based model), a widely used and simple method of calculating road vehicle emissions, offers easy accessibility by expressing emissions as a function of average speed. However, there are limitations in expressing emissions generated through complex mechanisms simply as a function of speed. Real-world driving tests using a portable emission measurement system can incorporate the impact of vehicle driving load on emissions. In this study, we analyzed real-world emissions data from 94 light-duty vehicles and developed time-based emission factors depending on vehicle speed and vehicle-specific power (VSP). We also propose a speed-VSP based model to estimate regional CO 2 and NOx emissions by combining time-based emission factors and vehicle operating times. The speed-based model and Speed-VSP based model exhibit a 44% difference in NOx emissions and a 29% difference in CO 2 emission. In a comparison of the two models against RDE test results, the speed-VSP based model achieved high accuracy in predicting NOx and CO 2 emissions with a lower root mean square error (RMSE). Specifically, for NOx emissions predictions, the speed-VSP based model achieved an RMSE of 122-270 mg/km, while the speed-based model showed a much higher RMSE of 435-476 mg/km. For CO 2 emissions predictions, the speed-VSP based model achieved an RMSE of 34-56 mg/km, while the speed-based model showed a much higher RMSE of 36-72 mg/km. The results of this study present an opportunity to reassess and improve conventional method of measuring and evaluating emissions from road transport., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The effects of premixed gas compositions on the combustion characteristics in micro pilot duel fuel (MPDF) conditions were investigated. Propane, hydrogen, and carbon dioxide gases were added to methane gas, and engine experiments were conducted under various premixed gas compositions. A single-cylinder heavy-duty engine with a combustion chamber volume of 1100 mm 3 and compression ratio of 17.0 was used. A 55 kW DC dynamometer was used to operate the single-cylinder dual-fuel engine at a constant engine speed. At high propane mixture ratios, knocking combustion occurred, accompanied by intense engine vibrations, owing to the low octane number of propane. Knocking combustion led to an increase in the combustion variation and ringing intensity (which represents the knocking combustion intensity). In contrast, at high ratios of hydrogen, which has a high octane number, knocking combustion was suppressed, and the speed of combustion was lower than that in the case of high propane mixture ratios. The optimum conditions corresponded to a ringing intensity of 3-5 MW/m 2 . The addition of even a small amount of propane gas enhanced the engine performances in misfiring conditions. In contrast, a considerable amount of hydrogen gas was required to prevent abnormal combustion because of the low density of hydrogen gas. The presence of carbon dioxide effectively stabilized MPDF combustion by suppressing knocking combustion., (© 2022. The Author(s).)

SARS-CoV-2 variants are of particular interest because they can potentially increase the transmissibility and virulence of COVID-19 or reduce the effectiveness of available vaccines. However, screening SARS-CoV-2 variants is a challenge because biosensors target viral components that can mutate. One promising strategy is to screen variants via angiotensin-converting enzyme 2 (ACE2), a virus receptor shared by all known SARS-CoV-2 variants. Here we designed a highly sensitive and portable COVID-19 screening biosensor based on the virus receptor. We chose a dual-gate field-effect transistor to overcome the low sensitivity of virus-receptor-based biosensors. To optimize the biosensor, we introduced a synthetic virus that mimics the important features of SARS-CoV-2 (size, bilayer structure, and composition). The developed biosensor successfully detected SARS-CoV-2 in 20 min and showed sensitivity comparable to that of molecular diagnostic tests (∼165 copies/mL). Our results indicate that a virus-receptor-based biosensor can be an effective strategy for screening infectious diseases to prevent pandemics.

Using mesoporous SiO 2 to encapsulate CsPbBr 3 nanocrystals is one of the best strategies to exploit such materials in devices. However, the CsPbBr 3 /SiO 2 composites produced so far do not exhibit strong photoluminescence emission and, simultaneously, high stability against heat and water. We demonstrate a molten-salts-based approach delivering CsPbBr 3 /mesoporous-SiO 2 composites with high PLQY (89 ± 10%) and high stability against heat, water, and aqua regia. The molten salts enable the formation of perovskite nanocrystals and other inorganic salts (KNO 3 -NaNO 3 -KBr) inside silica and the sealing of SiO 2 pores at temperatures as low as 350 °C, representing an important technological advancement (analogous sealing was observed only above 700 °C in previous reports). Our CsPbBr 3 /mesoporous-SiO 2 composites are attractive for different applications: as a proof-of-concept, we prepared a white-light emitting diode exhibiting a correlated color temperature of 7692K. Our composites are also stable after immersion in saline water at high temperatures (a typical underground environment of oil wells), therefore holding promise as oil tracers., Competing Interests: The authors declare the following competing financial interest(s): M.N.A., S.P., M.L., L.S., O.B., L.D.T., and L.M. are inventors on patent application IT IT102020000018481 that covers the synthesis of nanocomposites and their properties. L.M. is a member of the Advisory Board of Quantum Solutions., (© 2021 The Authors. Published by American Chemical Society.)

We developed a facile synthesis of nanocomposite powders of CsPbX 3 nanocrystals (NCs) embedded in silica. The synthesis starts from colloidal Cs 4 PbX 6 NCs that are mixed with tetraethyl orthosilicate in the presence of nitric acid, which triggers the sol-gel reaction yielding the formation of SiO x and the conversion of starting NCs into CsPbX 3 ones. The overall reaction delivers CsPbX 3 NCs encased in a silica matrix. The resulting CsPbX 3 /SiO x nano-composite powders exhibited enhanced moisture and thermal stability in air. Also, when mixing different CsPbX 3 /SiO x samples having diverse anion compositions, no interparticle anion exchange processes were observed, which is a further indication that the silica matrix acts as a robust barrier surrounding the NCs. Finallly, we used these composites as down-converter phosphors on top of a blue light-emitting diode (LED), delivering nearly ideal white light emission with the Commission Internationale de l'Eclairage (CIE) color coordinates (0.32, 0.33).

The heterogeneous nature of tumor-cell populations suggests that quantitative analysis at the single-cell level may provide better insights into cancer biology. Specifically, detection of multiple biomarkers from a single cell offers important initial information about cellular behavior. However, conventional approaches limit biomarker detection at the single-cell level. Here, we fabricated a polymer microwell array to capture single cells from prostate-cancer cell lines and quantitatively analyzed the expression of three different cancer-related biomarkers, CD44, EpCAM, and PSMA, without a membrane protein-extraction step. The resulting information on cell-surface biomarker distributions was compared with that from other standard analytical techniques. Interestingly, a large variation in CD44-expression levels was observed when the cell-proliferation cycle was modulated. On the other hand, the expression levels of EpCAM in three different cell lines are consistent among the different analytical methods with the exception of the microarray, where it has a different substrate material to adhere to. This observation clearly emphasizes that biomarker choice and environmental control are critical for properly understanding the single-cell state.

Estimations of CO 2 emissions and the potential to reduce heavy-duty vehicles in Korea under different reduction scenarios are presented in this paper. Technologically achievable CO 2 reduction rates are applied to four scenarios: the business as usual (BAU) scenario, mild scenario, normal scenario, and aggressive scenario. In estimating CO 2 emissions, a simulation model based on longitudinal vehicle dynamics was used in cooperation with average vehicle mileage traveled and the number of registered Korean heavy-duty vehicles. In the BAU scenario, which is the reference scenario, 30.82 million tons of CO 2 will be emitted in 2030, and CO 2 emissions will be reduced by 2.1%, 4%, and 5%, respectively, in mild, normal, and aggressive scenarios. In 2040, the reduction effects of these scenarios will be 5.7%, 10.9%, and 15.8%, respectively. These results indicate the range of available potential reduction of CO 2 by technical improvements or the CO 2 emission regulation of heavy-duty vehicles in Korea., (Copyright © 2018 Elsevier B.V. All rights reserved.)

We have developed a colloidal synthesis of nearly monodisperse nanocrystals of pure Cs 4 PbX 6 (X = Cl, Br, I) and their mixed halide compositions with sizes ranging from 9 to 37 nm. The optical absorption spectra of these nanocrystals display a sharp, high energy peak due to transitions between states localized in individual PbX 6 4- octahedra. These spectral features are insensitive to the size of the particles and in agreement with the features of the corresponding bulk materials. Samples with mixed halide composition exhibit absorption bands that are intermediate in spectral position between those of the pure halide compounds. Furthermore, the absorption bands of intermediate compositions broaden due to the different possible combinations of halide coordination around the Pb 2+ ions. Both observations are supportive of the fact that the [PbX 6 ] 4- octahedra are electronically decoupled in these systems. Because of the large band gap of Cs 4 PbX 6 (>3.2 eV), no excitonic emission in the visible range was observed. The Cs 4 PbBr 6 nanocrystals can be converted into green fluorescent CsPbBr 3 nanocrystals by their reaction with an excess of PbBr 2 with preservation of size and size distributions. The insertion of PbX 2 into Cs 4 PbX 6 provides a means of accessing CsPbX 3 nanocrystals in a wide variety of sizes, shapes, and compositions, an important aspect for the development of precisely tuned perovskite nanocrystal inks.