Reduction Ratio Research Articles

Anti-implantation and uterotonic properties of Mentha pulegium L. in female Sprague-Dawley rats

Background: Some traditional herbs disrupt endocrine-endometrial synchrony, affecting embryo-endometrium communication during fertility. Hormonal imbalances cause non-receptive conditions, leading to anti-implantation or abortion. Historically, Mentha pulegium has served for contraceptive and abortive purposes. Its effects on the post-coital contraceptive and hormonal activities were evaluated. Methods: Thirty-six Sprague-Dawley female rats were selected based on the presence of copulation plugs and received 200, 500, and 1000 mg/kg of Hydroethanolic leaf extract of Mentha pulegium L. (MPE) for seven days. Reproductive organ weights and serum estrogen and progesterone levels were measured. The resorption index, anti-implantation activity, and pre-implantation loss were also calculated using the number of implantation sites and resorptions in all treatments. Data were presented as mean±standard error mean (SEM), and significance was defined as p<0.05 using one-way ANOVA. Results: Post-coital administration of MPE resulted in resorptive, pre-implantation loss, and anti-implantation activity. A dose of 200 mg/kg reduced the number of implantations and exhibited a high resorption index, percentage pre-implantation loss, and anti-implantation activity. A marked decline in serum progesterone levels and a significant reduction in serum estrogen and progesterone ratio was observed at 200 mg/kg MPE. A significant increase in uterine weight was observed in the 500 mg/kg treatment. Doses of 500 and 1000 mg/kg resulted in a significant reduction in anti-implantation activity. Conclusions: The observed anti-implantation activity and pre-implantation loss suggest the abortifacient properties of MPE. However, its effects were seen to be dose-dependent.

Efficacy of N-acetylcysteine in reducing inflammation and oxidative stress to prevent complex regional pain syndrome type 1.

This study aimed to evaluate the effectiveness of N-acetylcysteine (NAC) in preventing complex regional pain syndrome type 1 (CRPS-1) by reducing proinflammatory cytokines and oxidative stress markers in patients with distal radius fractures. A retrospective single-center study at Bursa City Hospital involves patients over 50 years of age with distal radius fractures treated between January 2021 and December 2023. A total of 60 patients (mean age, 62.8 ± 5.1 years; 26 males and 34 females) were analyzed. Patients were divided into 2 groups: the NAC group (31 patients receiving 600-mg NAC daily for 3 months) and the control group (29 patients with no prophylactic medication). CRPS-1 diagnosis was based on Budapest criteria during multiple follow-up visits. Serum levels of interleukin (IL)-1 beta, IL-6, tumor necrosis factor-alpha (TNF-α), total oxidant status (TOS), and total antioxidant status (TAS) were measured at baseline and study end point. CRPS-1 positive patients had significantly higher levels of IL-6, TNF-α, and IL-1 (P < .001 for all), higher TOS (P < .001) and oxidative stress index (P < .001), and lower TAS (P < .001) compared with CRPS-1 negatives. The incidence of CRPS-1 was significantly lower in the NAC group (9.7%) compared with the control group (31.0%; P = .039). Logistic regression indicated a 78% reduction in CRPS-1 odds ratio with NAC treatment (odds ratio, 0.219 [95% confidence interval, 0.053-0.895]; P = .0322). NAC significantly reduced end-point levels and changes in IL-6 (P < .001), TNF-α (P < .001), and IL-1 (P = .038) and improved oxidative stress markers, showing higher TAS (P < .001), lower TOS (P < .001), and oxidative stress index (P < .001) compared with controls. NAC significantly reduced the risk of developing CRPS-1 by decreasing levels of proinflammatory cytokines and oxidative stress. This study highlights NAC's potential as a preventive treatment for CRPS-1 and emphasizes the importance of early intervention.

Experimental and numerical study on upper-room Far-UVC system under different ventilation schemes to disinfect airborne microorganisms in indoor environments

Many deadly infectious diseases are transmitted through airborne routes in indoor environments. Far UV upper-room system combined with proper ventilation is regarded as an effective approach to disinfect airborne microorganisms. Despite the current advances in the far UV upper-room system, various types of data are still lacking to guide the efficient design and the safe operation. This study combines field air sampling, laboratory experiments and computational fluid dynamics simulations to advance the knowledge on the potential of far UV radiation for disinfection and its safety design. Our findings reveal that seven out of the eight measured room spaces are categorised as slightly polluted (1201–2000 CFU m−3) or polluted (>2000 CFU m−3). Proteobacteria and Firmicutes constitute 65.2 ± 10.6 % and 21.2 ± 5.68 % of the bacterial composition in congregate settings, respectively. Ultraviolet radiation proves effective in deactivating pathogenic microorganisms, characterized by a decay rate constant ranging from 0.0446 m2 J−1 to 0.464 m2 J−1, depending on the wavelength and the type of pathogenic microorganisms. The time response of Ultraviolet radiation is up to 12 min to achieve 92.1 % sterilisation. Despite the reduction in the sterilisation ratio of Ultraviolet radiation, maintaining a high ventilation rate is highly recommended to eliminate genetic material from pathogenic microorganisms. When the excimer lamp is installed higher than 1.9 m above the floor level, the radiation intensities at both standing and sitting height become lower than the safety threshold value of 0.166 W m−2. A combination of UV radiation at 222 nm and ventilation is effective for neutralising both gram-positive and -negative bacteria and can contribute to stop the spread of infectious diseases in congregate settings.

Effects of double neonatal stress on female rat sexual behaviour

Neonatal stress affects psychological and physiological development and may be associated with affective disorders. The aim was to examine the effects of double neonatal stress (DNS) – a combination of limited bedding and nesting (LBN) and repeated maternal separation (MS) – on the oestrous cycle and sexual behaviour of adult female rats. LBN was achieved by removing part of the wood shavings from the boxes. In the control group, each box was lined with 100 g of wood shavings, while in the experimental group there were only 10 g of wood shavings. MS was performed from P1 (P0 = day of birth) to P15. At P90, the sexual response of females in oestrus was evaluated. Statistical analysis was performed using two-way analysis of variance followed by Tukey's test. The size and profile of the oestrous cycle and the sexual behaviour of female rats submitted to the DNS were considered, as well as the influence of female behaviour on the sexual response of male rats. Female rats submitted to DNS showed a reduction in the lordosis quotient, suggesting a reduction in female receptivity. These rats also showed a reduction in the number of hops and darts, the number of ear wiggles, and the genital exploration time rate, suggesting a reduction in proceptivity. The males that interacted with the females of the DNS group showed a reduction in intromission ratio. Experimental model that mimics neonatal factors that affect adult female sexual response will allow more effective interventions to prevent and treat such changes. In addition, analysis of the female sexual response makes it possible to assess the general state of health and quality of life. In female rats, DNS exerted inhibitory effects on sexual behaviour. LBN was probably the most important factor. In conclusion, combating childhood poverty can be a key measure to prevent problems in the sex life of adults and improve overall health.

The Influence of the Combined Addition of La–Ce Mixed Rare Earths and Sr on the Microstructure and Mechanical Properties of AlSi10MnMg Alloy

This study investigated the effect of adding La–Ce mixed rare earths and Sr on the microstructure and mechanical properties of AlSi10MnMg alloy. The experiment utilized different combinations of modifiers, including single La–Ce rare earths, single Sr, and the combined addition of La–Ce mixed rare earths and Sr. This study compared their effects on grain refinement, the modification of the α-Al phase and eutectic silicon phase, and tensile properties and hardness. The results showed that the combined modification of Sr and mixed rare earth elements significantly refined the grains, optimized the morphology of the α-Al phase and eutectic silicon phase, and improved the overall mechanical properties of the aluminum alloy. Under the combined modification, the addition of 0.02 wt.% Sr and 0.1 wt.% RE (La–Ce mixed rare earths) exhibited the most pronounced refining effect. The secondary dendrite arm spacing (SDAS) was reduced by 59.18%. The eutectic silicon phase transformed from coarse needle-like shapes to fine fibrous or granular forms, with an aspect ratio reduction of 69.39%. Meanwhile, the alloy’s tensile strength and hardness were significantly improved. The tensile strength increased to 240 MPa, achieving an increase of 23.08%; the yield strength increased to 111 MPa, achieving an increase of 18.09%; and the elongation reached 7.3%, achieving an increase of 73.81%. This indicates that the proper addition of Sr and mixed rare earths can significantly optimize the microstructure and enhance the mechanical properties of AlSi10MnMg alloy, providing an effective method for the preparation of high-performance heat-treatment-free aluminum alloys.

Abnormal circadian rhythms exacerbate dilated cardiomyopathy by reducing the ventricular mechanical strength.

Dilated cardiomyopathy (DCM) has etiological and pathophysiological heterogeneity. Abnormal circadian rhythm (ACR) is related to the development of DCM in animal models, but exploration based on clinical samples is lacking. Sleep apnea (SA) is the most common disease related to ACR, and we chose SA as the study object to explore ACR-DCM. We included a derivation cohort (n =105) and a validation cohort (n = 65). DCM patients were divided into SA and without SA group. RT-qPCR was used to determine the change of rhythm gene expression pattern of heart samples from different timepoints. We used single-nucleus RNA sequencing (snRNA-seq) to explore the abnormal transcriptional patterns in the ACR group, and we verified the findings by pathological staining, atomic force microscopy (AFM), and Rev-erbα/β knockout (KO) mice analysis. DCM patients with SA showed decreased amplitude of rhythm gene expression. SA group showed more severe dilation of left heart chambers. From snRNA-seq, ACR-DCM lost the morning transcriptional patterns, detailly, actin cytoskeleton organization of cardiomyocytes (CMs) disrupted and hypertrophy aggravated, and the proportion of activated fibroblasts (Fibs) decreased with the reduction of fibrotic area ratio. The results of pathological staining, mechanical experiments, and transcriptional feature of Rev-erbα/β KO mice supported the above findings. Compared with the non-SA group, left ventricular (LV) wall dilation was more severe and the structural strength was lower in DCM patients with SA, and phenotypic changes in CM and Fib were involved in this process. ACR-DCM was histopathologically characterized by a structurally weak ventricular wall.

Performance analysis of multiuser mmWave DCT-spread CP-Less OFDM communication system

In this paper, we propose a framework for multiuser mmWave DCT-Spread CP-less OFDM communication system and analyze it comprehensively. Due to excessive cyclic prefix (CP) usage in conventional multicarrier systems, spectral efficiency reduces and increases transmission latency. Our proposed system enhances spectral efficiency and reduces transmission latency. We introduce an image encryption algorithm based on DNA encoding combined with a chaotic map is introduced to enhance physical layer security (PLS). The impact of block diagonalization (BD) channel precoding for multiuser interference (MUI) reduction and designed subcarrier mapping with time-domain Tukey windowing for out-of-band (OOB) power emission reduction are investigated. In addition, the paper studies the applicability of discrete cosine transforms (DCT)-Spreading for peak-to-average power ratio (PAPR) reduction. Simulation results demonstrate that Turbo and Repeat and Accumulate (RA) channel coding and minimum mean square error (MMSE) and Cholesky decomposition (CD)-based zero-forcing (ZF) signal detection schemes improve bit error rate (BER) performance of the proposed system for different users.

A sharding blockchain protocol for enhanced scalability and performance optimization through account transaction reconfiguration

Sharding is a critical technology for enhancing blockchain scalability. However, existing sharding blockchain protocols suffer from a high cross-shard ratio, high transaction latency, limited throughput enhancement, and high account migration. To address these problems, this paper proposes a sharding blockchain protocol for enhanced scalability and performance optimization through account transaction reconfiguration. Firstly, we construct a blockchain transaction account graph network structure to analyze transaction account correlations. Secondly, a modularity-based account transaction reconfiguration algorithm and a detailed account reconfiguration process is designed to minimize cross-shard transactions. Finally, we introduce a transaction processing mechanism for account transaction reconfiguration in parallel with block consensus uploading, which reduces the reconfiguration time overhead and system latency. Experimental results demonstrate substantial performance improvements compared to existing shard protocols: up to a 34.7% reduction in cross-shard transaction ratio, at least an 83.2% decrease in transaction latency, at least a 52.7% increase in throughput and a 7.8% decrease in account migration number. The proposed protocol significantly enhances the overall performance and scalability of blockchain, providing robust support for blockchain applications in various fields such as financial services, supply chain management, and industrial Internet of Things. It also enables better support for high-concurrency scenarios and large-scale network environments.

4E Analysis of a new cogeneration system coupling heat pumps and PEMFC in summer and winter modes

In response to the ongoing optimization of energy systems and the promotion of clean energy, this paper introduces a new high-efficiency cogeneration system based on proton exchange membrane fuel cells (PEMFC). Named the Transcritical Combined Cooling Heating and Power with Subcooling Coupled ORC (CPTSO) system, it undergoes energy, exergy, economic, and environmental (4E) assessments to evaluate its performance in both summer and winter modes. This paper also analyzes the effects of key factors on the new system's performance. The results indicate that the new system performs more effectively overall and achieves faster cost recovery during winter operations. With varying degrees of subcooling (ΔTsubcooling), the system's average energy efficiency, fuel energy saving ratio (FESR), exergy efficiency, and pollutant reduction in winter are 60.97 %, 4.51 %, 17.16 %, and 33.35 % higher, respectively, than in summer. Changes in the main evaporation temperature (Te) result in winter improvements of 74.37 % in energy efficiency, 16.86 % in FESR, 17.6 % in exergy efficiency, and 45.5 % in pollutant reduction compared to summer. Similarly, adjustments to the outlet temperature of the gas cooler (Tg) lead to winter increases of 56.75 % in energy efficiency, 0.49 % in FESR, 17.1 % in exergy efficiency, and 29.3 % in pollutant reduction over summer values.

Adverse cardiovascular and kidney outcomes in people with SARS-CoV-2 treated with SGLT2 inhibitors

BackgroundWhether use of SGLT2 inhibitors reduces the risk of cardiovascular and kidney events in people who contracted SARS-CoV-2 infection is not clear.MethodsWe used the healthcare databases of the United States Department of Veterans Affairs to build a cohort of 107,776 participants on antihyperglycemic therapy and had SARS-CoV-2 infection between March 01, 2020 and June 10, 2023. Within them, 11,588 used SGLT2 inhibitors and 96,188 used other antihyperglycemics. We examined the risks of major adverse cardiovascular events (MACE)—a composite of death, myocardial infarction and stroke, and major adverse kidney events (MAKE)—a composite of death, eGFR decline > 50%, and end stage kidney disease after balancing baseline characteristics between groups through inverse probability weighting. Survival analyses were conducted to generate hazard ratio (HR) and absolute risk reduction per 100 person-years (ARR).ResultsOver a median follow up of 1.57 (IQR: 1.05–2.49) years, compared to the control group, SGLT2 inhibitors use is associated with reduced risk of MACE (HR 0.82 (0.77, 0.88), ARR 1.73 (1.21, 2.25)) and reduced risk of MAKE (HR 0.75 (0.71, 0.80), ARR 2.62 (2.13, 3.11)). Compared to the control group, SGLT2 inhibitors use is associated with reduced risk of the secondary outcomes of hospitalization (HR 0.94 (0.90, 0.98), ARR 1.06 (1.36, 1.76)), anemia (HR 0.71 (0.65, 0.76), ARR 2.43 (1.95, 2.90)), and acute kidney injury (HR 0.84 (0.79, 0.89), ARR 1.86 (1.29, 2.42)).ConclusionsAmong people with SARS-CoV-2 infection on antihyperglycemic therapy, compared to those on other antihyperglycemics, those on SGLT2 inhibitors have less risk of adverse cardiovascular and kidney outcomes.

In situ foam 3D printed microcellular multifunctional nanocomposites of thermoplastic polyurethane and carbon nanotube

Electrically conductive and mechanically robust thermoplastic polyurethane (TPU)/carbon nanotube (CNT) foams were achieved using a novel in situ foam 3D printing (F-3DP) process. Thermally expandable microspheres (TEMs), as blowing agent, were incorporated into the TPU/CNT filaments and fed to the F-3DP process. Foams with uniform morphologies and repeatable properties were achieved in a wide density range by solely regulating the nozzle temperature and its correlated flow rate. Overall, the degree of foaming increased substantially with an increase in the temperature, providing a density range of 0.96 to 0.17 g/cm3. It was interestingly found that a small amount of CNT (1 wt%) increased the expansion ratio. A further increase of CNT (to 3 and 5 wt%), however, caused a reduction in the expansion ratio. These opposing trends were attributed to the competing effects of CNT on the melt's thermal conductivity and viscosity. Both CNT content and nozzle temperature exhibited significant impacts on the tensile properties and electrical conductivity. This resulted in foams with diverse Young's modulus and strain at break in the range of 3.9–29.5 MPa and 260 to 52 %, respectively. More importantly, the electrical conductivity increased up to several orders of magnitude, as the foam expansion was increased due to temperature rise. This interesting finding was thoroughly discussed in terms of the enhanced inter-bead adhesion, vanishing inter-bead gaps, and realignment of CNTs around the growing TEMs. The results demonstrate a great potential of F-3DP to produce functional foams with controllable density and performance in a wide range.

The Uselessness of Anaerobic Antibiotic Coverage in Aspiration Pneumonia: A Systematic Review and Meta-Analysis

Introduction: Asthma is a prevalent respiratory condition, and biologic agents have proven effective in managing moderate to severe asthma. However, the role of biomarkers in guiding the use of biologic agents remains unclear. Method: On July 30, 2024, a systematic review and subsequent meta-analysis were conducted by searching three major online databases: PubMed, Web of Science, and Cochrane. Results: The final analysis included 10 studies with a total of 6,709 patients with moderate to severe asthma. The overall pooled effect across all ages demonstrated a rate ratio (RR) reduction of 0.61 (95% CI: 0.46 to 0.80; p &lt; 0.01; I² = 71%). Subgroup analysis revealed an onset or treated age of less than 18 years with RRs of 0.79 (95% CI: 0.62 to 1.02; p = 0.07; I² = 0%) and 0.88 (95% CI: 0.42 to 1.84; p = 0.73; I² = 14%), respectively. Patients with varying blood eosinophil levels showed a pooled RR of 0.51 (95% CI: 0.38 to 0.69; p &lt; 0.01; I² = 82.7%). However, blood eosinophil levels below 150/μL demonstrated a limited effect of biologic agents, with an RR of 0.77 (95% CI: 0.35 to 1.67; p = 0.50; I² = 87%). For patients with all levels of fraction of exhaled nitric oxide (FeNO), the RR was 0.43 (95% CI: 0.30 to 0.62; p &lt; 0.01; I² = 84%). The test for subgroup differences yielded a p-value of &lt; 0.001, indicating that patients with higher FeNO levels experienced a more significant reduction in RR. Conclusion: Patients with asthma onset or treatment before age 18 may benefit less from biologics. Blood eosinophil counts and FeNO levels aid in selecting these therapies.

Joint Optimization-Based QoS and PAPR Reduction Technique for Energy-Efficient Massive MIMO System

Massive multiple input multiple output (MIMO) is an innovative wireless communication technology that significantly enhances the capacity and efficiency of data transmission in modern networks. Massive multiple input multiple output, despite benefits, faces difficulties in managing numerous antennas affecting signal quality, peak-to-average power ratio (PAPR), and energy efficiency due to its scale and complexity. However, overcoming these complexities is vital for unlocking massive multiple input multiple output’s potential in high-quality, energy-efficient wireless communication. A proposed joint optimization-based technique aims to address these issues in massive MIMO systems. In phase 1, joint optimization with quality of service maximizes capacity via power distribution, employing the hybrid spider wasp Fick’s law algorithm. In phase 2, zero-forcing with symbol-level linear precoding, especially the stacked convolutional sparse bidirectional long short-term memory autoencoder (SCS–BiLSTMAE) network, efficiently reduces peak-to-average power ratio, collaborating for reduced bit rate error and peak-to-average power ratio through adaptive mapping. Refining the model involves precise hyperparameter tuning using the enhanced influencer buddy optimization algorithm. The proposed framework not only demonstrates exceptional performance, but the metrics also underscore the model's effectiveness in addressing diverse challenges, establishing it as a robust solution for quality enhancement, peak-to-average power ratio reduction, and energy efficiency. Additionally, the proposed model attains 28.14% greater system capacity than existing methods.

Elucidating the effect of cyclic plasticity on strengthening mechanisms and fatigue property of 5xxx Al alloys

The strength of non-heat-treatable 5xxx Al alloys is derived from solid solution strengthening and strain hardening, the absence of a precipitation strengthening response results in their lower strength. In this study, significant improvements in strength can be achieved by subjecting three different Mg concentrations 5xxx Al alloys to cyclic plasticity. A quantitative analysis of the respective contributions to the yield strength has been conducted by combining transmission electron microscopy and atom probe tomography. Additionally, the fatigue performance and fatigue mechanism of the cyclic strengthened 5xxx Al alloys have been thoroughly studied due to its transformation from non-heat-treatable to precipitation strengthening. We demonstrate that the high-cycle fatigue (HCF) strength of the cyclically strengthened state only experiences a minor improvement compared to the as-received state, which is significantly disproportionate to the enhancement in tensile strength. This disparity is primarily attributed to the changes in microstructure and fatigue mechanisms, resulting in a reduction in fatigue ratio. This study provides important insights for expanding research on cyclic plasticity methods in fatigue performance, and can aid in the development of improved processes for optimal fatigue resistance.

Complexation process and binding parameters of curcumin and short amylose with V7-type helix structure

Pre-formed V7-type short amylose (SA) could interact with curcumin to form inclusion complex (IC) thereby to improve the stability of curcumin. However, the complexation mechanism of V7-type SA and curcumin is not clear, which limit the improvement of inclusion efficiency. To obtain a starch nanocarrier with high loading capacity, the encapsulation process and interaction parameters of V7-type SA-curcumin IC was studied. The analysis results demonstrated that stoichiometric ratio value of the SA-curcumin complex was around 1. V7-type SA performed excellently in the delivery of curcumin attributing to their high loading capacity (over 20 %). It was found that curcumin could enter into the pre-formed helical cavity of SA to form an IC. The conformation change of SA caused the reduction in the interaction ratio in the last 20 ns of simulation. However, SA and curcumin always remained complexation status during the simulation. Hydrogen bonds (H-bonds) and hydrophobic interaction were the most critical acting forces involved in the formation and stability of V7-type SA-curcumin complex. Molecular docking presented that H-bonds interaction between curcumin ligand and V7-type SA chain (O3 at the 25th glucose unit, and O6 at the 17th and 20th glucose units) were found. Furthermore, the hydrophobic interactions were discovered between curcumin ligand and SA chain (18th, 19th, 21st, 22nd and 23rd glucose units). Short abstractTo obtain a nanocarrier with high loading capacity, the interacting mechanism of curcumin and V-type short amylose (SA) was studied. The results demonstrated that curcumin could enter into the pre-formed helical cavity of SA to form an inclusion complex. SA and curcumin always remained complexation status during the simulation. Hydrogen bonding and hydrophobic interaction were the most critical acting forces involved in the formation and stability of V7-type SA-curcumin complex.

Fluorescence imaging in reducing anastomotic leak after left-sided colorectal resections: a systematic review and updated meta-analysis.

The objective of this systematic review and meta-analysis was to pool randomized trials of patients undergoing left-sided colorectal anastomosis, comparing the use of fluorescence perfusion imaging versus visual inspection in reducing anastomotic leaks. Databases searched included PubMed, Cochrane Library, Scopus, CINHAL (EBSCO), and Google Scholar based on the concepts: randomized, colorectal, anastomotic leak, and fluorescence imaging. The risk of bias was assessed using RoB2 and the certainty of the evidence with the GRADE Pro tool. The analysis used the log odds ratio for dichotomous data with 95% confidence intervals. Back-transformation of the log odds to odds ratio was performed for the summary of findings. All syntheses used the Random-effects model. Six randomized trials were included with 1949 patients and 204 events (leaks). Three trials included exclusively rectal cancer patients, while the other three involved benign and malignant pathologies of the sigmoid and rectum. The use of ostomy and preoperative radiation was variable. None of the studies had a high risk of bias. The pooled odds ratio for anastomotic leak reduction with Indocyanine Green (ICG) fluorescence was 0.586 (95% CI: 0.434-0.792). An absolute reduction of 4.7% in leak rates was observed, with no statistical heterogeneity (I2 = 0; p = 0.529). Due to clinical heterogeneity, the quality of evidence was rated moderate. The use of ICG is associated with reduced leak rates following left-sided colorectal anastomosis with moderate confidence. ICG may be considered a standard of care given the clinically significant benefit in decreasing anastomotic leaks.

A study on misfire detection by calculating crank angular velocity considering in-cylinder gas properties

Misfire detection using a new crank angular velocity calculation was studied for high efficiency and robust engine ignition performance and combustion stability control. An applying production was achieved by applying in-cylinder gas properties prediction and its correction to the misfire index and verifying it under various conditions. The relationship between the misfire index and torque fluctuation was consistent depending on the combustion control factors EGR, injection timing, pilot injection quantity change, and environmental change factors water temperature and intake gas temperature. On the other hand, it was found that the piston speed changes due to the in-cylinder pressure with respect to the intake pressure, and the crank angular speed needs to be corrected. Commonly used sensors for engine cooling water temperature, intake gas temperature, intake pressure, and engine speed were used as representative values for in-cylinder pressure, and the cooling loss was subtracted from the polytropic index and the reduction in specific heat ratio due to EGR was corrected. By building a new model that calculates the compression end pressure model from the polytropic index and adding corrections to the misfire index, we applied logic that can be calculated for each cycle to the ECU onboard. Conventionally, compression end pressure prediction requires calculations that take combustion conditions into account, which requires the number of sensors and their accuracy, and a long calculation time. However, in this study, Authors focused on the fact that the pressure at TDC during a misfire does not include ignition and combustion phenomena and expressed the necessary physical phenomena using the minimum sensor information. As a result of the above, a control structure at a level that can be applied to products was obtained.

Novel multi-layer field shaper in electromagnetic manufacturing process technology of tube joining for uniform deformation

Electromagnetic joining technology is widely utilized in assembling tubular components due to its ability to exert uniform magnetic pressure. To augment this pressure, a field shaper structure has been introduced. However, the conventional design may impair the uniformity of deformation, particularly at the seam. This study presents a novel multi-layer field shaper (MLFS) to enhance deformation uniformity. The performance of the MLFS was evaluated and optimized through experimental trials and simulation analysis. The results showed that MLFS achieved a 300 % increase in minimum deformation with a 56 % reduction in the aspect ratio, demonstrating that our design effectively balances efficiency with deformation uniformity. The magnetic cubic decay formula could fit the simulation data well with R2 higher than 0.999. MLFS was found to enhance uniformity by creating a more even magnetic field that decreased the curvature near the plastic hinge. Compared to altering the interlayer thickness, adjusting the interlayer angle can further enhance uniformity. When the rotation angle is 60°, the radius range can be further reduced by 32.5 %, 39.0 %, and 12.2 % at energy levels of 27 kJ, 30 kJ, and 33 kJ, respectively. The above results indicate that by designing and optimizing MLFS, sufficiently large and uniform electromagnetic forces were obtained.

Ultra-low-defect homoepitaxial micro-LEDs with enhanced efficiency and monochromaticity for high-PPI AR/MR displays

The issue of brightness in strong ambient light conditions is one of the critical obstacles restricting the application of augmented reality (AR) and mixed reality (MR). Gallium nitride (GaN)-based micro-LEDs, renowned for their exceptional brightness and stability, are considered the foremost contenders for AR applications. Nevertheless, conventional heteroepitaxial growth micro-LED devices confront formidable challenges, including substantial wavelength shifts and efficiency droop. In this paper, we firstly demonstrated the high-quality homoepitaxial GaN-on-GaN micro-LEDs micro-display, and thoroughly analyzed the possible benefits for free-standing GaN substrate from the material-level characterization to device optoelectronic properties and micro-display application compared with sapphire substrate. The GaN-on-GaN structure exhibits a superior crystal quality with ultra-low threading dislocation densities (TDDs) of ~ 105 cm−2, which is three orders of magnitude lower than that of GaN-on-Sapphire. Through an in-depth size-dependent optoelectronic analysis of blue/green emission GaN-on-GaN/ Sapphire micro-LEDs from 100 × 100 shrink to 3 × 3 μm2, real that a lower forward voltage and series resistance, a consistent emission wavelength (1.21 nm for blue and 4.79 nm for green @ 500 A/cm2), coupled with a notable reduction in efficiency droop ratios (15.6% for blue and 28.5% for green @ 500 A/cm2) and expanded color gamut (103.57% over Rec. 2020) within GaN-on-GaN 10 μm micro-LEDs. Last but not least, the GaN-on-GaN micro-display with 3000 pixels per inch (PPI) showcased enhanced display uniformity and higher luminance in comparison to its GaN-on-Sapphire counterpart, demonstrating significant potentials for high-brightness AR/MR applications under strong ambient light.

City configurations to optimise pedestrian level ventilation and wind comfort

Mediterranean coastal cities encounter two conflicting urban environmental challenges. First, strong winds that pose a risk of pedestrian wind discomfort on coastal streets, and second, weak winds that lead to inadequate outdoor ventilation in inner urban fragments. This study aims to optimise pedestrian level ventilation and wind comfort in Izmir, a compact coastal city in the Mediterranean climate. Three hypothetical city configurations were created based on four morphological parameters: street layout, urban street canyon form, tower layout, and tower height variation. Computational fluid dynamics simulations of the city configurations were performed and validated by wind tunnel experiments. The weak, comfortable, and strong winds were determined and mapped at the pedestrian level to assess each city configuration's performance. The results show that using the strategy of a shifted coastal street layout with adding towers on second-row blocks results in a 20 % reduction of the maximum wind velocity ratio on coastal streets compared to a grid street layout without towers. Moreover, positioning step-up towers on step-up city blocks and shifted towers on step-down city blocks can increase pedestrian-level ventilation efficiency by up to 73 %. The research methodology and findings can be transferred to other climates and urban environments and guide urban designers.