Low Load Conditions Research Articles

Study on 20 V LDMOS With Stepped-Gate-Oxide Structure for PMIC Applications: Design, Fabrication, and Characterization

In this brief, a 20 V laterally diffused metal-oxide-semiconductor (LDMOS) device with the concept of stepped-gate-oxide (SGO) was fabricated with standard 0.15 μm BCD technology. Compared with the conventional shallow-trench-isolation LDMOS (STI-LDMOS), the SGO structure features a straight conduction path on a silicon surface, based on our past development experience, and therefore, an ON-resistance reduction of about 20% can be obtained. This brief demonstrated the LDMOS from a power-switching perspective, considering both optimization design and characterization aspects. The optimum device was demonstrated with R <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>$_{ON,sp}$</tex> </formula> of 4.92 mΩ ·mm², breakdown voltage (BV) of 23.8 V, and device figure of merit (FOM) of 20 mΩ -nC. By combining with optimum power stage design, the buck converter efficiency showed 93.88% at low load condition and 93.98% at high load condition, achieving an outstanding dc-dc converting performance.

Spray strategy and mixer optimization in Urea-SCR system based on frozen flow modeling

An integrated after-treatment device model was established by Converge and the experiments were conducted on rapid urea deposits platform under low and medium load conditions. The model was validated by back pressure of catalysts, mixer wall temperature and distribution of urea deposits. In order to reduce the computational costs, the urea injection strategy and mixer structure was optimized based on the frozen flow method. The effects of frozen flow method on the simulation errors and computational costs were evaluated by film mass, film distribution and cycle numbers. The results show that the simulation errors after frozen flow were larger under low load condition but lower under medium load condition. However, the frozen flow method could effectively reduce the cycle numbers under both low and medium load conditions, which was reduced by 9.05% and 17.77%. Furthermore, the cycle numbers were reduced by 31.23% in 5 times injection simulation. With the optimal scheme under low and medium load conditions, the urea deposition rate was reduced by 43.51% and 23.16%. The mass of NH3 was increased by 23.99% under medium load condition. The NH3 uniformity coefficient increased by 5.04% and 2.69%, and the mixer back pressure declined by 24.40% and 27.44%.

Medical-psychological aspects of professional deformation of personality development among emergency medical staff

The aim of the work. To study the specifics of professional burnout formation considering the relationship between its levels and typological personality traits of emergency medical staff. Materials and methods. A medical and psychological survey was conducted among 120 medical professionals of the “Regional Clinical Hospital – Center for Emergency Medical Care and Disaster Medicine” in Kharkiv, Ukraine. A representative sample included 85 respondents – emergency medical staff (paramedics and doctors), 28 men and 57 women, aged 20 to 78 years, with a mean age of 40.78 ± 13.43 years. The levels of professional burnout were determined according to the Maslach Burnout Inventory – General Survey (MBI-GS), the classification of professional burnout risk – according to R. Kalimo, stress triggers and causes provoking it were determined according to the Differential Stress Inventory (DSI) questionnaire. Statistical processing of the factual material was carried out using the IBM SPSS 26.0 computer program and the Vienna Tests System. Results. Emergency medical services staff showed pronounced professional burnout phenomena across all age groups. The high level of emotional exhaustion was most pronounced in 57.1 % of respondents aged 30–40 years and in 42.0 % of those over 40 years, along with this, the moderate level of emotional exhaustion was most pronounced in 1/3 of respondents under the age of 29 years. A high level of depersonalization phenomena prevailed in 40.9 % and 42.9 % of respondents under the age of 29 and 30–40 years, respectively, and a moderate level of depersonalization was almost equally represented in 33.3 % of respondents aged 30–40 years and over 40 years. A high level of diminished sense of personal accomplishment due to a lack of work-related activity value was almost equally represented across all age groups of emergency medical services staff, however, its highest manifestation was in 85.7 % of respondents over 40 years, and the moderate level of this burnout characteristic prevailed in 28.6 % of respondents aged 30–40 years. According to the classification of professional burnout by R. Kalimo et al., only 9.1 % of emergency medical services staff under 29 years and 3.0 % of those over 40 years were at risk of burnout. Nevertheless, some symptoms of burnout were almost equally presented in all age groups, but 71.4 % of respondents aged 30–40 years had the most evident manifestations. According to the DSI questionnaire, 13.6 % and 11.9 % of respondents under the age of 29 and over 40 years, respectively, were of a very tense type of response to stressors in conditions of high professional load with unsuccessful attempts to overcome problem situations. A low level of resilience with successful coping strategies under low-load conditions was more pronounced in 14.3 % of emergency medical services staff over 40 years old and in 9.1 % of those under 29 years of age. Conclusions. The highest levels of professional burnout on the “emotional exhaustion” scale of the MBI-GS questionnaire had more than half of the respondents among emergency medical staff aged 30–40 years, depersonalization phenomena were most pronounced in emergency medical staff under the age of 29 and 30–40 years, and the high level of “reduced personal accomplishment” was equally prevailed among emergency professionals of all age groups, but individuals over the age of 40 years experienced a lack of work-related activity value to a greater extent. One-quarter of the emergency medical staff respondents of all age groups were of the very stressed type with low resilience, being characterized by moderate workload and low coping ability and of the type with low resilience and low professional expectations and demands, but with successful coping strategies, providing the conditions for further decrease in the personal resources of specialists and the progression of the professional burnout phenomena.

Study on preparation process parameters and tribological properties of porous PI materials

PurposePreviously, the effect of pore-forming agents on the properties of pore size and morphology was studied. In this paper, we determine the optimal combination of parameters by tensile strength and perform tribological tests with optimal combination of parameters.Design/methodology/approachIn this paper, porous polyimide (PI) materials were fabricated using vacuum hot molding technology. The orthogonal experiment was designed to test the mechanical properties of porous PI materials with the process parameters and the content of pore-forming agent as the changing factors. The porous PI oil-bearing materials were obtained by vacuum immersion, and tribological test were carried out.FindingsThe results showed that porous PI oil-bearing materials are suitable for low-speed and low-load conditions. The actual value of the friction coefficient basically match with the theoretical value of the regression analysis, and the errors of the friction coefficient are within 10% and 3%, respectively, which proves that the method used in the study is feasible for the friction coefficient prediction.Originality/valueIn this paper, we have produced a new porous oil-bearing material with good tribological properties. This study can effectively predict the friction coefficient of PI porous material.

Micellar catalysis beyond the hydrophobic effect: Efficient palladium catalyzed Suzuki-Miyaura coupling of water and organic solvent insoluble pigments with food grade surfactants

Micellar catalysis is having a dramatic impact in improving the sustainability of a wide variety of chemical transformations, including most of the popular palladium mediated carbon–carbon and carbon–nitrogen bond forming reactions. The Suzuki-Miyaura coupling is one of the earliest examples of micellar catalyzed reactions and it is still a very much active research field even at industrial scale. So far, micellar catalysis proved particularly efficient in enabling the high yield, low catalyst loading and mild reaction condition coupling of hydrophobic reagents in a water solution of selected surfactants. In this paper we show that the use of aqueous solutions of a mixture of food grade lecithin and the industrial surfactant Tween 80 not only enables efficient coupling in water of hydrophobic chemicals, but also provides a very resourceful tool for the functionalization of water and organic solvent insoluble pigments of interest for the dye and printed electronic industries.

Instrumentation response of full-scale thin airfield pavements

ABSTRACT Instrumentation response data from full-scale accelerated pavement testing have been used to inform pavement design models and enhance service life predictions to ensure long-term operating conditions. However, some aircraft, i.e. military aircraft, may have a requirement to operate under relatively short-term conditions on airfields that are constructed below optimal conditions. Accordingly, the objective of this study was to construct, traffic, and collect instrumentation data from airfield pavement test sections constructed with asphalt thicknesses below existing military standards. Three asphalt thicknesses and two base course strengths were evaluated using two different aircraft simulators each at two tire inflation pressures. Earth pressure cells, single-depth deflectometers, and asphalt strain gauges were used to collect response data. Instrumentation response data were sensitive to increases in asphalt layer thickness, i.e. an increase in asphalt layer thickness generally resulted in an improvement in measured response albeit in relatively thin asphalt layers. Instrumentation response data were more sensitive to tire inflation pressure changes at higher loading conditions when compared to lower loading conditions. Finally, a layered elastic analysis using a non-uniform tire pressure distribution was found to provide a better approximation of measured earth pressure cell response than that of a typically assumed uniform pressure distribution.

High bladder pressure reduces the ability to filter out interference from distractors in low perceptual load condition.

According to the load theory of attention, an active cognitive control mechanism is needed to ensure that behaviour is controlled by target-relevant information when distractors are also perceived. Although the active cognitive control mechanism consists of working memory, cognitive flexibility, and inhibition components, predictions regarding the load effects of this mechanism were derived mostly from studies on working memory. We aimed to test whether these predictions are also valid for an inhibition component. The inhibitory load was manipulated physiologically by creating different bladder pressure and its effects on distractor interference were examined under low and high perceptual load conditions. The results indicated that the availability of inhibitory control resources was important for decreasing the interference of distractors in the low perceptual load condition and that the high perceptual load reduced the effects of distractors independently from the availability of inhibitory resources. The results were consistent with the predictions of load theory, and to the best of our knowledge, the study provided the first piece of evidence in terms of the load effect of inhibition component on distractor interference.

When Less Is More: Investigating Factors Influencing the Distraction Effect of Virtual Reality From Pain.

Virtual reality (VR) is a powerful method of redirecting attention away from pain. Yet, little is known about which factors modulate the size of this distraction effect. The aim of this study was to investigate the role of cognitive load and inter-individual differences in the cognitive and affective domain on heat pain thresholds during a VR game. Ninety healthy participants (mean age ± SD: 23.46 ± 3.28; 50% identified as male and 50% as female) played a low and high load version of a VR game while heat pain thresholds and heart rate were recorded. The effects of cognitive load were assessed by computing the difference in pain thresholds between the high and low load condition for each participant. In addition, we computed the difference in heart rate variability (HRV) measures between both conditions to explore whether these would be correlated with the difference in heat pain thresholds. Prior to the VR session, participants completed questionnaires about their emotional distress, pain-related cognitions, and different executive functioning tasks. Contrary to our expectations, not all participants benefitted from a higher load in terms of distraction from pain. Logistic regression analysis revealed that participants who reported more emotional distress were more likely to exhibit higher pain thresholds in the low relative to the high load condition. Accordingly, these participants tended to show marginally higher HRV in the low compared to the high load condition. Our study demonstrates that the potential benefits of an increased cognitive load in VR on pain sensitivity depends on individual differences in affective state.

Do cognitive load and ADHD traits affect the tendency to prioritise social information in scenes?

We report two experiments investigating the effect of working memory (WM) load on selective attention. Experiment 1 was a modified version of Lavie et al. and confirmed that increasing memory load disrupted performance in the classic flanker task. Experiment 2 used the same manipulation of WM load to probe attention during the viewing of complex scenes while also investigating individual differences in attention deficit hyperactivity disorder (ADHD) traits. In the image-viewing task, we measured the degree to which fixations targeted each of two crucial objects: (1) a social object (a person in the scene) and (2) a non-social object of higher or lower physical salience. We compared the extent to which increasing WM load would change the pattern of viewing of the physically salient and socially salient objects. If attending to the social item requires greater default voluntary top-down resources, then the viewing of social objects should show stronger modulation by WM load compared with viewing of physically salient objects. The results showed that the social object was fixated to a greater degree than the other object (regardless of physical salience). Increased salience drew fixations away from the background leading to slightly increased fixations on the non-social object, without changing fixations on the social object. Increased levels of ADHD-like traits were associated with fewer fixations on the social object, but only in the high-salient, low-load condition. Importantly, WM load did not affect the number of fixations on the social object. Such findings suggest rather surprisingly that attending to a social area in complex stimuli is not dependent on the availability of voluntary top-down resources.

Misfire Detection Using Crank Speed and Long Short-Term Memory Recurrent Neural Network

In this work, a new approach was developed for the detection of engine misfire based on the long short-term memory recurrent neural network (LSTM RNN) using crank speed signal. The datasets are acquired from a six-cylinder-inline, turbo-charged diesel engine. Previous works investigated misfire detection in a limited range of engine running speed, running load or misfire types. In this work, the misfire patterns consist of normal condition, six types of one-cylinder misfire faults and fifteen types of two-cylinder misfire faults. All the misfire patterns are tested under wide range of running conditions of the tested engine. The traditional misfire detection method is tested on the datasets first, and the result show its limitation on high-speed low-load conditions. The LSTM RNN is a type of artificial neural network which has the ability of considering both the current input in-formation and the previous input information; hence it is helpful in extracting features of crank speed in which the misfire-induced speed fluctuation will last one or a few cycles. In order to select the engine operating conditions for network training properly, five data division strategies are attempted. For the sake of acquiring high performance of designed network, four types of network structure are tested. The results show that, utilizing the datasets in this work, the LSTM RNN based algorithm can overcome the limitation at high-speed low-load conditions of traditional misfire detection method. Moreover, the network which takes fixed segment of raw speed signal as input and takes misfire or fault-free labels as output achieves the best performance with the misfire diagnosis accuracy not less than 99.90%.

Эколого-биологические особенности пижмы обыкновенной (Tanacetum vulgare L.) в экотопах Кабардино-Балкарской Республики

The bulk of the preparations of medicinal plant raw materials of common tansy (Tanacetum vulgare L.) are wild plants. Flores Tanaceti industrial collections are produced in the central regions of the European part of Russia. In the North Caucasus, T. vulgare grows scattered, so the data on the bioresource potential of the species require clarification. The aim of the study was to study the ecological and biological features of T. vulgare in the ecotopes of the Kabardino-Balkarian Republic (KBR). The study of the area, morphological and phytochemical variability of T. vulgare was carried out on the territory of the KBR in 2018-2021 at the start of flowering plants.The study of the range, ontogenesis and ecological and biological features of T. vulgare was carried out on the territory of the KBR in 2018-2021 at the start of flowering plants. According to the results of the study, the range of T. vulgare covers three floristic subregions: Chegemo-Chereko-Sukansky, Leskeno-Lashkutinsky and Jurassic depressions. The highest occurrence and abundance of plants are typical for forest, forest-steppe, meadow, floodplainecotopes of the foothill zone of the KBR. In the studied phytocenoses, T. vulgare is a companion species with an average abundance of 0,3-2,5%. The zone of ecological optimum for the species is meadow-steppe and drymeadow moisture, fairly rich soils, moderate moisture variability, and weak pasture digression. Under conditions of low load, T. vulgare cenopopulations form normal full-membered, unimodal spectra with a maximum on mature generative specimens. Under stress conditions, the spectra become incomplete, discontinuous, unimodal, right-handed, with a maximum on old-aged generative plants. Among the studied morphological and economically valuable traits of T. vulgare, high variability was noted for the number of anthologies in the inflorescence, medium variability for the number of generative shoots and flower yield, low and very low variability for the height of the shoot, the content of phenolic substances, and the diameter of the anthorax. In mid-mountain cenopopulations compared with foothill a significant increase in the content of the sum of flavonoids and phenolcarboxylic acids in flowers, shoot height, a decrease in the number of baskets in the inflorescence, the number of generative shoots, and the yield of raw materials were found. The nature of the correlation between the accumulation of phenolic compounds in flowers and the studied morphological traits can be used to select T. vulgare ecotypes and include them in the breeding process.

Comparison between the mechanical properties and environmental impacts of 3D printed synthetic and bio-based composites

The present work aims at studying both the mechanical properties and environmental impacts of two 3D printable composites materials: glass fiber reinforced polyamide (GlassPA) and bio-based hemp fiber reinforced polylactide (HempPLA). Hence, this study aims to provide a comprehensive overview of the two considered materials, supporting the sustainable development of industrial additive manufacturing processes. To this purpose, tensile specimens were produced using a Fused Deposition Modeling process and then tensile tested to evaluate the mechanical properties of the printed materials. The environmental impacts of both GlassPA and HempPLA were investigated using the Life Cycle Assessment methodology; a cradle to gate approach was chosen to evaluate all the relevant input of the tensile specimens production. Mechanical tests showed that synthetic composite is characterized by higher strength and stiffness values than the bio-based composite. However, HempPLA results in noticeably lower environmental impacts than GlassPA in terms of Cumulative Energy Demand and Global Warming Potential indicators, proving to be a feasible alternative to glass fiber reinforced polymers in application with low load conditions.

Vibration and Noise Reduction for a Switched Reluctance Motor by Reduction in Circular Ring Mode Vibration under Low Load Condition

Vibration and Noise Reduction for a Switched Reluctance Motor by Reduction in Circular Ring Mode Vibration under Low Load Condition

Optical Diagnostics of Misfire in Partially Premixed Combustion Under Low Load Conditions

Optical Diagnostics of Misfire in Partially Premixed Combustion Under Low Load Conditions

A Comparative Study on Gasoline/Diesel-Fueled Rcci Combustion at Different Premixed Ratios and High-Egr Diesel Ci Combustion in an Ic Engine Under Low Load Conditions

A Comparative Study on Gasoline/Diesel-Fueled Rcci Combustion at Different Premixed Ratios and High-Egr Diesel Ci Combustion in an Ic Engine Under Low Load Conditions

Optimization of a cyclic activated sludge system for norfloxacin wastewater treatment under low-load conditions

Optimization of a cyclic activated sludge system for norfloxacin wastewater treatment under low-load conditions

PMSM design optimization concerning sensorless performance and torque ripple

This paper proposes a multi objective design optimization approach concerning sensorless performance and torque ripple for Permanent Magnet Synchronous Machine. Sensitivity analysis of design parameters has been accomplished for critical parameters selection and metamodels are generated based on critical variables. Based on these metamodels, the optimization process aims to propose an optimal machine geometry to improve sensorless performance without compromising torque ripple and average torque. The metamodel assisted optimization process has been proven to reduce computational cost with a good accuracy. The selection of the optimal solution was achieved based on multi-objective optimization process using NSGA-II. The optimal solution is validated by finite element analysis and has proved an extending of 100% of the feasibility area of sensorless control with only an increase of 3% of torque ripple. The fidelity model of optimized solution is generated and sensorless control algorithm is simulated with fidelity model to prove that the optimized solution could be operated sensorless in low speed high load conditions.

Analysis and experimental research on the influence of VVT point selection on exhaust temperature in low speed operating conditions

During the development of a model equipped with dual VVT engines, a higher temperature of the catalyst was discovered. Therefore, the sweep point of VVT is optimized under low speed and high load conditions. The test results show that VVT has a significant effect on the temperature of the catalytic converter, and the temperature of the catalytic converter has decreased after optimization. At the same time, the VVT opening has little effect on the dynamics. In addition, VVT has an effect on the knocking tendency of the engine. When the knocking tendency increases, the temperature of catalytic converter and power performance of the engine are deteriorated. On the contrary, if the ignition angle can be advanced, the performance of the engine can be optimized.

Behavioral and neurocognitive effects of judo training on working memory capacity in children with ADHD: A randomized controlled trial

BackgroundChildren with Attention Deficit Hyperactivity Disorder (ADHD) face deficits in working memory capacity that often persist into adulthood. In healthy peers, exercise targeting motor skill acquisition benefits visuospatial working memory, but its potential to reduce ADHD-related deficits remains unclear. We investigated the effect of a judo training program targeting motor skills on behavioral and neurocognitive indices of working memory capacity in children with ADHD. MethodsChildren with ADHD aged 8 to 12 years (N = 57) were randomly allocated to a judo training group and a wait-list control group. The training program encompassed 120 min of judo per week over three months. Before and after the intervention period, participants completed a bilateral Change Detection task with low and high memory load conditions and the Movement Assessment Battery for Children-2 (MABC-2). The contralateral delay activity (CDA) elicited by the cognitive task was recorded using electroencephalography. ResultsCompared to the control group, the judo training group showed a higher K-score on the Change Detection task and an increased negativity of the CDA on the high load condition following the intervention, when pretest scores (and confounders) were accounted for. In contrast, no group differences were found for MABC-2 score. ConclusionIn children with ADHD, judo training may complement the pharmacological treatment by increasing the effectiveness of working memory maintenance processes. On a behavioral level, this improvement is accompanied with an increased capacity to store visuospatial information.

High verbal working memory load impairs gesture-speech integration

Abstract While previous studies have shown the importance of visuo-spatial working memory in the processing of co-speech iconic gestures, clear evidence for a potential involvement of the verbal working memory (vWM) is currently lacking. To address this issue, participants in the present study were presented with a dual task paradigm. The main outcome variable was the performance on a Stroop-like gesture task which provides a behavioural index of gesture-speech integration. Participants performed this task under conditions of either high or low concurrent vWM load. Unlike in previous studies, the number of words to remember in the high load condition was determined by their individual verbal span rather than being fixed. Results showed reaction time costs in the form of longer reaction times for semantically incongruent gesture-speech combinations as compared to congruent combinations. However, this semantic congruency effect disappeared when the vWM load increased. This result suggests a causal involvement of verbal working memory capacity in gesture-speech integration.