Role‐play is often used as a pedagogical technique by counsellor educators to help counsellors‐in‐training (CITs) learn and practise counselling skills. This study used qualitative content analysis ...to assess the effectiveness of Chat Generative Pre‐Trained Transformer (ChatGPT), an artificial intelligence (AI) chatbot, in simulating client role‐play to facilitate practising counselling skills. The author used 10 case vignettes to conduct a simulated role‐play where ChatGPT was asked to simulate the client and author as counsellor. The results indicated that ChatGPT demonstrated authenticity, consistency, appropriate emotional expression, cultural sensitivity, empathy and self‐awareness while portraying the client. However, at times, ChatGPT's responses to the counsellor's questions appeared overly idealised, lacking the authenticity typically observed in real clients. Furthermore, ChatGPT, as a simulated client, lacked non‐verbal cues, limiting the overall experience of counselling skill practice. Recommendations for CITs and future research are discussed.
•Fuel injection pressure & timings affect engine performance, emissions and combustion.•Rapid combustion, higher cylinder pressure & ROHR at advanced injection timings.•Superior performance at lower ...FIP giving lower BSFC & emissions, & higher BTE.•Emission characteristics improve with advanced fuel injection timings.•Particulate number concentration in a CI engine increases with increasing engine load.
For a diesel engine, fuel injection pressure (FIP) and injection timings are very important parameters, which influence the engine performance, emissions, and combustion. Other injection parameters affecting engine performance are rate of injection, injection pattern, number of injections etc. A single cylinder research engine was used to experimentally determine the effects of fuel injection strategies and injection timings on engine combustion, performance and emission characteristics. The experiments were conducted at constant speed (2500rpm) with two FIPs (500 and 1000bars respectively) and different start of injection (SOI) timings. Cylinder pressure and rate of heat release (ROHR) were found to be higher for lower FIPs however advanced injection timings gave higher ROHR in early combustion stages. Brake thermal efficiency (BTE) increased with increased injection pressures while exhaust gas temperature and brake mean effective pressure (BMEP) increased upto 500bars. These parameters reduced slightly with increase in FIP. For advanced SOI, BMEP and BTE increased, while brake specific fuel consumption (BSFC) and exhaust gas temperature reduced significantly. Carbon dioxide (CO2) and hydrocarbon (HC) emissions decreased however nitrogen oxide (NOx) emissions increased with increasing FIP. Lower CO2 and HC emissions, and significantly higher NOx emissions were observed with advanced injection timings. Particulate number–size distribution increased with increasing engine load however it reduced with increasing FIP.
Most of the two-stage converters for electric bike battery charging comprise of a boost converter for power factor correction (PFC) followed by a dc-dc converter with universal input voltage. These ...two-stage conversions suffer from poor efficiency and increased component count. In this paper, a single-stage switched inductor Cuk converter based PFC converter is proposed, which offers high step-down gain, low current stress, high efficiency, and reduced component count. The operational analysis and design equations for various components of the proposed converter are carried out in continuous current mode. This paper presents mathematical modeling, analysis, simulation, and experimentation on the proposed converter rated for 500 W, 48 V/10.4 A. The performance investigation of the proposed converter with respect to power quality indices like voltage total harmonic distortion (THD), current THD, and total power factor is carried out with various types of loads such as resistive load and battery load in both constant voltage (CV) and constant current (CC) mode. Furthermore, the dynamic performance of the proposed converter with battery charging is investigated in CV mode and CC mode with respect to the wide range of supply variations.
•Combustion phasing is analyzed by fitting probability density functions.•Combustion stability improves on increasing intake air temperature.•Test conditions with late start of combustion have larger ...cyclic variations.•Large deviations from normal distribution in combustion duration for knocking/misfire.•GEV distribution covers full range of distribution shapes for combustion duration/phasing.
Homogeneous Charge Compression Ignition (HCCI) engines have potential for excellent fuel economy and extremely low emissions of NOx and PM. HCCI engines however do not have any direct control on the start of combustion timings, which makes HCCI combustion control extremely challenging. Characterization of cyclic variations of various combustion parameters is required for design and development of closed loop control of HCCI engines. Combustion stability and cycle-to-cycle variations of HCCI combustion parameters using gasoline like fuels (methanol, ethanol and butanol) were investigated in a modified four-cylinder, four-stroke engine. The experiments were conducted by varying the intake air temperature (Ti) and relative air–fuel ratio (λ) as well as engine speed. In the steady state engine operation, cylinder pressure signals for 2000 consecutive engine cycles were acquired for each test condition. From this large volume of experimental data collected, cyclic variations of various combustion parameters were analyzed. To evaluate the cycle-to-cycle variations of HCCI combustion parameters, statistical parameters such as coefficient of variation (COV) and standard deviation of each parameter were calculated for all test conditions. Combustion phasing was also analyzed by fitting different probability density functions (statistical distributions). Best-fit distribution for all test conditions can then be used for predicting and controlling the HCCI combustion timing for engine control.
Particulate and NOx emissions from diesel engine are the biggest challenges faced in making diesel engines environmentally benign. Measures adopted for reducing gravimetric particulate emission to ...meet the prevailing emission regulations necessarily always do not reduce particulate number concentration, which has profound adverse health effects. Therefore it is important to investigate effect of fuel injection parameters, especially fuel injection pressure and start of injection timings on particulate size and number distribution in diesel exhaust. In the present study, a single cylinder research engine is used for experimental assessment of the effects of fuel injection strategies and start of fuel injection timing on particulate size-number, surface area, and volume concentration distributions by using engine exhaust particulate sizer (EEPS) spectrometer. Investigations have been conducted at three different fuel injection pressures (300, 500, 750 bar) and four different start of injection timings. The experimental data indicates that the particulate size-number concentration increases with increasing engine load (BMEP) and it reduces with increasing fuel injection pressure.
An efficient method was developed for the synthesis of a tetracyclic fused indole and isoindoline ring system, under metal-free conditions. The hypervalent iodine PIDA-mediated regioselective as well ...as chemoselective intramolecular cascade oxidative cyclization of 2-(1-arylethynyl)benzamides afforded 11-aryl-6 H -isoindolo2,1- a indol-6-ones at room temperature in good to excellent yields.
In this paper, new SVPWM switching sequences for six-phase asymmetrical induction motor drives are derived with the aim to reduce inverter's switching losses. Total three switching sequences are ...introduced in this paper. These sequences are derived such that the phases get continuously clamped when a current of the phases is around its peak magnitude and hence reduced switching losses are recorded. The comparative performances of these modulation techniques are studied with two existing switching sequences. Simulation, analytical and experimental results are presented. Based on these results, it is found that new switching sequences reduce switching losses effectively in dual three phase inverters.
This study used a correlational research design to explore the relationship between secondary traumatic stress, counsellor professional identity and career factors, including work setting and amount ...of counselling experience, among counsellor practitioners. A sample of 1,218 counsellors completed an online survey including the Secondary Traumatic Stress Scale (STSS), Professional Identity Scale in Counseling and career factors. Career factors included context of work environments including years of experience, licence status, type of practice and work setting. Multiple regression analysis with forward selection demonstrated that, out of all the variables, professional identity emerged as the best predictor of secondary traumatic stress. One‐way ANOVA showed significant group differences in the level of counsellors' secondary traumatic stress based on work setting, level of experience, type of practice and gender. Discussion explores how career and personal factors impact counsellor experiences of professional identity and secondary trauma in mental health settings.
The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high ...efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120–150
°C) and at different air–fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air–fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO
x
emissions are lower than 10
ppm however HC and CO emissions are higher.
Homogeneous charge compression ignition (HCCI) engines have potential to provide both diesel like efficiencies and very low NOx and particulate matter (PM) emissions. There is growing global interest ...in using alternative biofuels in order to reduce the reliance on conventional fossil fuels. Therefore this experimental study was carried out to investigate performance, combustion and emission characteristics of HCCI engine fueled with ethanol and methanol and compare it with baseline gasoline fuel. The experiments were conducted on a modified four-cylinder four-stroke engine at different engine speeds using port fuel injection technique for preparing homogeneous charge. To achieve auto-ignition of air–fuel mixture in the combustion chamber, intake air pre-heater was used. In-cylinder pressure data acquisition with subsequent heat release analysis and exhaust emission measurements were done for combustion and emission diagnostics. In this paper, effect of intake air temperature and air–fuel ratio on combustion parameters, thermal efficiency, combustion efficiency, ringing intensity and emissions in HCCI engine is analyzed and discussed. Results show that methanol and ethanol are good replacements to gasoline in HCCI combustion mode.
•HCCI operating window decreases with increasing engine speed.•Methanol shows lower IMEPmax compared to gasoline and ethanol.•Third order polynomial shows variation of combustion duration with SOC timings.•Methanol auto-ignites earlier than gasoline and ethanol in HCCI mode.•Combustion duration in HCCI operating range is less than 15 CAD.•Alcohols have higher ringing intensity for optimum combustion phasing.
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