Limited Rate Research Articles

PDS 70b Shows Stellar-like Carbon-to-oxygen Ratio

Abstract The ~5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation and evolution within its natal environment. Here, we report the first spin constraint and C/O measurement of PDS 70b from Keck/KPIC high-resolution spectroscopy. We detected CO (3.8σ) and H2O (3.5σ) molecules in the PDS 70b atmosphere via cross correlation, with a combined CO and H2O template detection significance of 4.2σ. Our forward-model fits, using BT-Settl model grids, provide an upper limit for the spin rate of PDS 70b (<29 km s−1). The atmospheric retrievals constrain the PDS 70b C/O ratio to 0.28 − 0.12 + 0.20 (<0.63 under 95% confidence level) and a metallicity [C/H] of − 0.2 − 0.5 + 0.8 dex, consistent with that of its host star. The following scenarios can explain our measured C/O of PDS 70b in contrast with that of the gas-rich outer disk (for which C/O ≳ 1). First, the bulk composition of PDS 70b might be dominated by dust+ice aggregates rather than disk gas. Another possible explanation is that the disk became carbon enriched after PDS 70b was formed, as predicted in models of disk chemical evolution and as observed in both very low-mass stars and older disk systems with JWST/MIRI. Because PDS 70b continues to accrete and its chemical evolution is not yet complete, more sophisticated modeling of the planet and the disk, and higher-quality observations of PDS 70b (and possibly PDS 70c), are necessary to validate these scenarios.

Application of Sooty Tern Optimization Algorithm on Solar‐Wind‐Battery‐Thermal Integrated Dynamic Economic Emission Dispatch Problems

ABSTRACTThe current challenges faced by conventional power plants, including increasing load demand over time, high generation costs, and excessive emissions from fossil fuels, have been helped to overcome by the integration of renewable energy sources (RESs) alongside conventional thermal power units. In this article, traditional dynamic economic emission dispatch (DEED) is enhanced by incorporating RESs, including two solar units, two wind units, and one battery power unit, forming the solar‐wind‐battery‐thermal (SWBT) integrated DEED (SWBTDEED). This integration aimed at reducing generation costs and minimizing excessive fuel emissions, and combining cost and emissions over a 24 h period. Four different test systems, each incorporating 6, 10, 30, and 40 thermal units alongside the same RESs, are considered to meet varying load demands hourly throughout the day. This article demonstrates that, in addition to reducing generation costs, SWBTDEED is capable of reducing emissions by 38.28%, 28.48%, 20.67%, and 20.44% for four test systems, thereby protecting the environment. The sooty tern optimization algorithm (STOA) is proposed in this article for solving complex DEED and SWBTDEED problems, considering various constraints such as generation limits, ramp rate limits, valve point loading, and Weibull distribution. Finally, the robustness, optimization efficiency, and capability of the STOA technique in handling complex nonlinear constraints are demonstrated in the results section, showcasing its ability to achieve optimal results compared to other algorithms such as the sine‐cosine algorithm, backtracking search algorithm, differential evolution, and particle swarm optimization.

Middle segment preserving pancreatectomy versus total pancreatectomy: a comparative analysis of short- and long-term outcomes.

Middle-segment preserving pancreatectomy (MSPP) serves as an alternative to total pancreatectomy (TP) for preserving the pancreatic body in multifocal pancreatic neoplasms. Despite the potential benefits of TP, the detailed short- and long-term prognoses remain unclear. We evaluated the feasibility of MSPP by comparing the perioperative outcomes and postoperative endocrine and exocrine functions with those of TP. The study included 10 TP and 7 MSPP patients. Patients with pancreatic ductal adenocarcinoma and invasive intraductal papillary mucinous carcinoma were excluded. MSPP was associated with a high incidence (57.1%) of postoperative pancreatic fistula (POPF); however, there were no cases of post-pancreatectomy hemorrhage or postoperative mortality in any group. The postoperative hospital stay and readmission rates were comparable between the groups. At 1year postoperatively, MSPP reduced the risk of new-onset insulin-dependent diabetes mellitus, maintained good glycemic control with minimal hypoglycemic events, and preserved skeletal muscle, subcutaneous fat, and visceral fat. One patient in the MSPP group with a neuroendocrine tumor had postoperative recurrence in the para-aortic lymph node. Despite the high POPF rate and oncologic limitations, MSPP showed superior long-term outcomes in glycemic control and preservation of body composition. MSPP may be an acceptable treatment option for selected patients.

Exploring seismic warning thresholds for vehicle-track systems through combined shaking table tests and dynamic numerical simulations

This study conducted vehicle-track shaking table model tests at the Seismic Laboratory of the China Academy of Building Research, employing both unidirectional (horizontal) and bidirectional (horizontal and vertical) seismic waves. Discussions were made on the dynamic response of the vehicle-track system and the mechanism of derailment, providing data support for the research on seismic early warning thresholds for vehicles. Additionally, three-dimensional finite element numerical simulations were performed on the vehicle-track dynamic model, successfully incorporating track irregularities into the model. In this paper, the main conclusions are as follows: The limits of the wheel load reduction rate and that of the derailment coefficient specified in China’s national standard “Code for Dynamic Performance Evaluation and Test Identification of Railway Vehicles” are conservative. The primary cause of vehicle derailment was identified as horizontal vibration of the track structure induced by seismic activity. Different seismic waves have varying effects on the dynamic response of the vehicle-track model, necessitating further research on the impact of seismic wave spectrum characteristics on vehicle safety during operation. When horizontal and vertical seismic waves are simultaneously applied, horizontal seismic waves have a greater impact on dynamic response. The numerical simulation results align well with experimental results, confirming the accuracy of the vehicle-track dynamic numerical model. It is recommended to adopt a more conservative seismic early warning threshold of 0.04 g to ensure the safety of train operation.

Optimizing reserve-constrained economic dispatch: Cheetah optimizer with constraint handling method in Static/Dynamic/Single/ Multi-Area Systems

Managing the power-generating units on the horizon of one-day scheduling considering all practical equality, inequality, and realistic constraints has always been a significant challenge in power systems. The constraints, such as valve-point effects, prohibited operation zones, transmission losses, and ramp rate limits corresponding to dynamic economic dispatch, change the optimization problem to a complex, nonlinear, non-smooth, high-dimensional, and non-convex one. Therefore, an efficient algorithm and a suitable constraint handling method are needed to solve practical constrained dynamic economic dispatch (DED). This paper proposes a newly developed Cheetah optimizer (CO) that coincides with a backward-forward constraint handling method to tackle the optimum operational cost. The CO algorithm’s performance is verified using eight DED and ED test cases from five different systems. The suggested technique is compared with several state-of-the-art optimization algorithms regarding the effectiveness of achieved results. Numerical results evaluate the performances of the CO advantages on the benchmarks and the DED cases where the results of 5-,10- and 30-unit systems are enhanced in different cases. To achieve a higher level of realism in modeling the ED and DED problem, adopting a multi-area DED (MADED) approach has emerged as a promising strategy. In this paper, three distinct cases of MAED and MADED problems are investigated to demonstrate the effectiveness of the proposed method. Specifically, in cases involving DED-10 and 30 units, two-area 40 units ED, and four-area 40 units DED, significantly improved solutions were obtained compared to previous studies.

CAUSES AND EFFECT OF COMMUNITY INSTABILITY ON SOCIO-ECONOMIC ACTIVITIES OF THE PEOPLES OF BORNO STATE, NIGERIA

This paper examines the causes and implications of Boko Haram insurgency on socio-economic activities of the people’s of Borno State, Nigeria. Available factors advanced in the process of the study helped understand what motivating people to join the Boko Haram sect in Borno State and other states of the North-eastern region of Nigeria. It is no longer a news that Boko Haram in the waves of their insurgency in Borno State recorded a killing of thousands of innocent’s people, while destroyed and burnt down government and public properties and infrastructures worth Billions of Naira. Besides, the Boko Haram continued indiscriminate attacks pushed millions of people to internally displaced persons camps and forced thousands of business men and women to abandon their businesses thereby created an unprecedented joblessness, hunger and abject poverty in Maiduguri Borno State. However, it is evident that schools of all level were temporarily closed in the mid of the insurgency for certain period, while public health centres were equally closed in some local government areas due to the pressure of the Boko Haram indiscriminate attacks and killings. All efforts by the security agents to cease the Boko Haram insurgency activities failed to yield positive result. However, little or no attention has been given to the negative consequences of the Boko Haram insurgency on socio-economic activities of the people of Borno State. Its against this backdrop, this paper is intended to study the implications of the Boko Haram insurgency activities on socio-economic activities of the peoples of Borno State. Five objectives, two hypotheses were raised to answer the study questions to comprehend the work. A qualitative research design is adopted using primary and secondary sources of data collection method to generates and adequate information on what influenced the peoples to pledges allegiance to Boko Haram sect, and to what extent the Boko Haram insurgency activities affected the peoples socio-economic activities. A purposive sampling technique is used to select the study respondents. The study target population was drawn from two senatorial districts of Borno State. Borno Central Senatorial District and Northern Borno Senatorial District respectively. Four local government areas were chosen from the two senatorial zones, two each, these are Maiduguri Metropolis, Bama LGA, Kukawa LGA and Mobbar LGA. A sampling size of 379 respondents were selected, 95 respondents from each of the four local government areas chosen. A descriptive statistic, mean and standard deviation as adopted using upper and lower limits of decision rate of 3.0 mean coupled with 5 Likert scale method were utilized to analyze the data and interpret the results. The results of the study revealed that the community instability caused by Boko Haram insurgency in Borno State has posed a serious threat to all sectors of human endeavors, includes, education, healthcare, agriculture and specifically paralyzed the socio-economic activities of the peoples of Borno State. The paper concluded that the damages have been done to almost all the sectors of human endeavors by the activities of Boko Haram insurgency hence the need for investing efforts to revive the areas affected, such as education, healthcare delivery, agriculture and so on. However, this paper is equally recommended that the local governments, state and federal government as well as national and international non-governmental organization and philanthropist should as a matter of urgency join hands together and assist the victims of the Boko Haram insurgency displaced from their business activities and ensuring that all affected sectors of human endeavor are effectively functioning. It is also recommended that government should come up with plan to regulates the affairs of both Islamic and Christianity to avoid radicalization of our growing youth in the future.

Understanding Rate and Capacity Limitations in Li-S Batteries Based on Solid-State Sulfur Conversion in Confinement.

Li-S batteries with an improved cycle life of over 1000 cycles have been achieved using cathodes of sulfur-infiltrated nanoporous carbon with carbonate-based electrolytes. In these cells, a protective cathode-electrolyte interphase (CEI) is formed, leading to solid-state conversion of S to Li2S in the nanopores. This prevents the dissolution of polysulfides and slows capacity fade. However, there is currently little understanding of what limits the capacity and rate performance of these Li-S batteries. Here, we aim to deepen our understanding of the capacity and rate limitation using a variety of structure-sensitive and electrochemical techniques, such as operando small-angle neutron scattering (SANS), operando X-ray diffraction (XRD), electrochemical impedance spectroscopy, and galvanostatic charge/discharge. Operando SANS and XRD data give direct evidence of CEI formation and solid-state sulfur conversion occurring inside the nanopores. Electrochemical measurements using two nanoporous carbons with different pore sizes suggest that charge transfer at the active material interfaces and the specific CEI/active material structure in the nanopores play the dominant role in defining capacity and rate performance. This work helps define strategies to increase the sulfur loading while maximizing sulfur usage, rate performance, and cycle life.

Fracture caging in a lab fault to prevent seismic rupture during fluid injection

Seismic risk associated with deep fluid injection is a major holdback for geothermal energy development. Currently adopted mitigation measures include traffic light protocol and cyclic stimulation methods that retroactively limit injection pressures and flowrates based on observed seismic activity to hopefully reduce the likelihood of triggering large seismic events. Fracture caging presents an alternative proactive approach to seismicity mitigation that does not require flow rate or injection pressure limits. The caging concept is to pre-drill boundary wells around injection wells to contain all injected fluid. Prior experimental and numerical work demonstrated successful caging of tensile hydraulic fractures but did not investigate caging in shear faults. To fill this knowledge gap, this study focuses on caging of injection-induced shear fractures in a critically stressed lab-scale shear fault. Experiment variables include mechanical versus hydraulic shearing and cage size by varied well spacing. Acoustic activity was monitored using two calibrated acoustic emission systems, each having a different sensitivity bandwidth. This constitutes what we call Caged Geothermal Systems (CGS) as a modified version of Enhanced Geothermal Systems (EGS), but with CGS using more wells, an accelerated drilling timetable, much higher flow rate limits, and less proppant. We demonstrate successful caging in a lab-scale shear fault with a high recovery of the injected fluid and prevention of large critical rupture events.

Need for national guidance regarding proactive care of infants born at 22-23 weeks' gestation.

With recent rapid improvements in neonatal intensive care, the limit of viability has shifted downward to 22-23 weeks' gestation. The younger the gestational age of preterm infants, the higher the risk of survival despite severe neurodevelopmental impairments. For infants born at 22-23 weeks' gestation, the limit of viability, neurodevelopmental outcomes, and survival rates may be determined by the quality of proactive care. Owing to the high risk of severe neurodevelopmental impairment in 22-23 weeks' gestation, proactive care is sometimes withheld according to ethical or legal considerations, and there are significant differences in the provision of proactive care and survival rates across countries or institutions. Additionally, there are differing or even lacking guidelines regarding the care of these infants across countries and institutions. Japan and Sweden are countries with well-established national guidance and proactive care for infants born at 22-23 weeks' gestation, resulting in higher survival rates among them. In Korea, where there is an extreme shortage of neonatologists, maternal transfer before delivery at 22-23 weeks' gestation to high-activity regions with appropriate neonatal intensive care unit resources, such as adequate personnel and facilities similar to the centralized care model seen in Sweden, is crucial for improving the survival rates of infants born at 22-23 weeks' gestation. The survival of these infants largely depends on the quality of proactive care provided. This rate is not static and can be improved through proactive case management based on national guidance and the implementation of enhanced neonatal intensive care practices, including centralization of care.

Orientation-independent quantification of macromolecular proton fraction in tissues with suppression of residual dipolar coupling.

Quantitative magnetization transfer (MT) imaging enables noninvasive characterization of the macromolecular environment of tissues. However, recent work has highlighted that the quantification of MT parameters using saturation radiofrequency (RF) pulses exhibits orientation dependence in ordered tissue structures, potentially confounding its clinical applications. Notably, in tissues with ordered structures, such as articular cartilage and myelin, the residual dipolar coupling (RDC) effect can arise owing to incomplete averaging of dipolar-dipolar interactions of water protons. In this study, we demonstrated the confounding effect of RDC on quantitative MT imaging in ordered tissues can be suppressed by using an emerging technique known as macromolecular proton fraction mapping based on spin-lock (MPF-SL). The off-resonance spin-lock RF pulse in MPF-SL could be designed to generate a strong effective spin-lock field to suppress RDC without violating the specific absorption rate and hardware limitations in clinical scans. Furthermore, suppressing the water pool contribution in MPF-SL enabled the application of a strong effective spin-lock field without confounding effects from direct water saturation. Our findings were experimentally validated using human knee specimens and healthy human cartilage. The results demonstrated that MPF-SL exhibits lower sensitivity to tissue orientation compared with , , and saturation-pulse-based MT imaging. Consequently, MPF-SL could serve as a valuable orientation-independent technique for the quantification of MPF.

Abstract 4143264: A Case of Spike-on-T Phenomenon and Polymorphic Ventricular Tachycardia

Background: R-on-T phenomenon occurs when an electrical stimulus is delivered at a critical point during ventricular repolarization. This can initiate ventricular arrhythmias like polymorphic ventricular tachycardia (PMVT). We describe a case of ventricular pacemaker spikes delivered on the T wave causing PMVT. Case: A 53-year-old female with CAD s/p stent, postpartum cardiomyopathy s/p Bi-V CRT-D (Boston Scientific G124), and paroxysmal atrial fibrillation presented for elective endoscopy and colonoscopy to evaluate her dysphagia and abdominal pain. Her CRT-D was reprogrammed from DDD pacing with lower rate limit (LRL) 50 bpm to an asynchronous Bi-V DOO mode at 50 bpm (‘electrocautery mode’) for the procedure (tachy therapy disabled). Her LV-RV offset was 40 msec. Prior to receiving sedation or medications, she was found unresponsive. Telemetry showed Spike-on-T phenomenon which initiated PMVT. She was externally defibrillated with 200J and received magnesium and an IV amiodarone bolus. She returned to sinus rhythm, but one minute later had another Spike-on-T event initiating PMVT. She was successfully defibrillated with 360J. Post-shock EKG showed an asynchronous Bi-V paced rhythm at 50 bpm. Decision Making: The patient was admitted to the CCU for post-resuscitation care. Her electrolytes and cardiac enzymes were unremarkable. Her CRT-D was reprogrammed to DDD 80-140 bpm. Transthoracic echocardiogram showed normal biventricular systolic function. Cardiac catheterization did not show obstructive CAD. After reprogramming of her device, she had no further events. After initial treatment with IV amiodarone load, she was discharged home on oral magnesium gluconate. Discussion: The only intervention prior to her procedure was device reprogramming (DDD 50 bpm to DOO 50 bpm). Telemetry showed pacer spikes initiating PMVT. Given the LV-RV offset of 40 msec, she would have received these two tightly coupled pacemaker spikes in an asynchronous mode, in this unfortunate instance during her T wave. While her bowel preparation may have led to electrolytes abnormalities, post-resuscitation electrolytes were normal. Fortunately, she received prompt therapy and was reprogrammed with increased LRL. Conclusion: We described a case of Spike-on-T PMVT prior to colonoscopy without obvious provocation other than asynchronous pacemaker spikes. Reprogramming devices in DOO mode with increased LRL may prevent PVCs and asynchronous pacemaker spikes from triggering PMVT.

Fast and light-efficient wavefront shaping with a MEMS phase-only light modulator

Over the last two decades, spatial light modulators (SLMs) have revolutionized our ability to shape optical fields. They grant independent dynamic control over thousands of degrees-of-freedom within a single light beam. In this work we test a new type of SLM, known as a phase-only light modulator (PLM), that blends the high efficiency of liquid crystal SLMs with the fast switching rates of binary digital micro-mirror devices (DMDs). A PLM has a 2D mega-pixel array of micro-mirrors. The vertical height of each micro-mirror can be independently adjusted with 4-bit precision. Here we provide a concise tutorial on the operation and calibration of a PLM. We demonstrate arbitrary pattern projection, aberration correction, and control of light transport through complex media. We show high-speed wavefront shaping through a multimode optical fiber – scanning over 2000 points at 1.44 kHz. We make available our custom high-speed PLM control software library developed in C++. As PLMs are based upon micro-electromechanical system (MEMS) technology, they are polarization agnostic, and possess fundamental switching rate limitations equivalent to that of DMDs – with operation at up to 10 kHz anticipated in the near future. We expect PLMs will find high-speed light shaping applications across a range of fields including adaptive optics, microscopy, optogenetics and quantum optics.

Inverse opal TiO2-CdS photonic crystal beads with slow light effect for photocatalytic degradation

Photocatalytic oxidation technology using solar energy is an effective strategy to solve environmental pollution and energy shortage. To avoid angle dependence of traditional photonic crystal photocatalysts and address the limitations of high charge recombination rate and low light utilization of TiO2, this study proposed a novel inverse opal TiO2/CdS photonic crystal beads (IO TiO2/CdS PCBs) photocatalyst. By leveraging the synergistic coupling of PCBs’ slow light effect and TiO2/CdS heterojunction, the photocatalytic activity was significantly enhanced. The results revealed that the PCBs matching the blue edge with TiO2′s electronic band gap (IO TiO2-140 PCBs) exhibited the highest apparent rate constant of 0.01901 min−1. By introducing CdS to form a heterojunction with TiO2, the photocatalytic performance was further improved by effectively inhibiting the recombination of photogenerated carriers. The degradation rate of RhB reached 96.6 % in 60 min, outperforming that of IO TiO2 at 65.1 %, with the rate constant increasing by 3.1 times. Electron spin resonance and trapping experiments indicated that h+ was the main active specie, and the possible reaction mechanism path was proposed. The combination of “extrinsic” modifications by doping CdS and “self-structural” modifications by shaping TiO2 into periodic IO PCBs structure provided a systematic insight on the design of novel photocatalysts.

Photon blockade in a high-damping cavity via a gain-type coupler

Abstract We propose a scheme to implement photon blockade in a non-Hermitian circuit quantum electrodynamics (circuit-QED) system where a single-mode cavity interacts with a two-level emitter through virtual photon excitation mediated by a coupler resonator. A damping compensation regime is introduced by the phase-lag arising from the medium mode, thereby the periodic exceptional points (EPs) are observed at which the system achieves gain-damping balance. This regime enables photon blockade to occur within the single-mode cavity with high-damping rate by controlling the gain circuit of the coupler, which breaks the limitation of a low-damping rate for photon blockade under weak drive and relaxes the stringent requirements on the quality factor of the cavity. The numerical simulations for the second-order correlation function, obtained using reported experimental parameters, exhibit excellent agreement with our analytical results. The findings of this study provide a circuit-QED solution for single-quantum devices based on the high-damping cavities, which is of great significance for integrated quantum computing networks.

Association of Organ Procurement Organization Volume with CMS Performance Evaluations

Under 2020 Centers for Medicare & Medicaid Services (CMS) conditions of coverage, Organ Procurement Organizations (OPOs) will be decertified if their 95% upper confidence limit for donation or transplant rate falls below the previous year's median (tier 3) and must recompete if either is below the 75th percentile (tier 2). This study examines associations of CMS metrics with OPO volume and evaluates an alternate observed-to-expected tiering system using simulation analysis and CMS’s OPO public report. In 2021, CMS tier 3 and 2 OPOs had significantly larger volumes than tier 1 OPOs (median=2,042 vs. 2,124 vs. 1,003, p=0.028). In a simulation scenario in which OPOs should be CMS tier 2, large OPOs had 95% probability of needing to recompete vs. 26% for the smallest OPOs. The observed-to-expected method misclassified OPOs as underperforming ∼5% of simulated cases independent of volume. CMS methodology assigned a worse tier than observed-to-expected to 24-54% of OPOs across years. Results indicate that the current CMS methodology systematically identifies larger OPOs as underperforming, independent of quality, suggesting alternative statistical evaluations are needed to assess OPO performance accurately and improve donation processes of care and transplant rates.

Measurements of Heavy Elements and Radioactivity Concentration Levels in Types of Fertilizers and Pesticides Commonly Used in Sana’a Yemen

This study aims to measure heavy metals (HMs) concentration and radioactivity concentration levels in fertilizer and pesticide samples collected from local markets in Sana’a, Yemen. Gamma spectroscopy employing a Survey Sodium Iodide NaI (TI) RIIDEYM-G detector was used for radiation and dose assessments. As for heavy metal analyses, this study used Inductively Coupled Optical Emission Spectroscopy (ICP-OES). Thirty samples were collected from local markets in Sana’a, Yemen. Radioactivity measurements show low levels of radioactivity concentration. The average dose rates due to fertilizer and pesticide samples were 1.14 and 1.07 mSv/y, respectively. These values are nearly equal to the recommended annual radiation dose rate limit (1mSv/y) recommended by the International Commission on Radiological Protection (ICRP). For heavy metal analysis, it was found that the average concentrations of heavy metals (HMs) (cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)) in the fertilizer samples were 1.08 mg/kg, 4.944 mg/kg, 13.8495 mg/kg, 274.371 mg/kg, 3.30446 mg/kg, 15.35686 mg/kg, and 24.4547 mg/kg, respectively. Heavy metal concentrations in fertilizer samples were mainly less than European (EU) guideline limits, with the exception of a few samples. The average concentrations of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn) in the pesticide samples were 0.8 mg/kg, 0.5784 mg/kg, 52.280 mg/kg, 73.4651 mg/kg, 2.4482 mg/kg, 3.199 mg/kg, and 1.1309 mg/kg, respectively. The heavy metal concentrations in pesticide samples were less than the corresponding values in fertilizer samples.

Determination and description of a vehicle's maximum jerk capacity

Both Transient Optimal and Quasi-Steady-State vehicle modelling are frequently used for minimum time manoeuvre and minimum lap-time simulations for motorsport/vehicle development purposes. Quasi-Steady-State methods have been shown to perform such tasks with low computational cost but produce results with measurable deviation from equivalent Transient Optimal studies. It is hypothesised that bounding point-mass models with jerk limits will improve alignment with Transient Optimal simulations through the consideration of transient behaviours such as control application rates and inertia. This work presents a new method for the determination of a vehicle's maximum jerk capacity from a seven degree-of-freedom vehicle model. A range of results from this proposed technique are presented and show the sensitivity of jerk capacity to changes in control application rate limits and yaw inertia, as well as current vehicle velocity, acceleration, and jerk. It is proposed that further exploration of the validity of the jerk limit calculation method take place through characterisation of said limits and application to a point-mass model, after which comparison to Transient Optimal and Quasi-Steady-State equivalents can occur.

1D supramolecular assembly-induced emission and colorimetry toward precise onsite mercury(II) detection

Manipulation of the one-dimensional (1D) supramolecular assembly of platinum(II) terpyridyl complex is promising for achieving precise onsite mercury(II) detection in complex environments, but still challenging. Herein, by systematic molecular design of platinum(II) terpyridyl complex, chloride-mediated 1D supramolecular assembly has been successfully achieved, exhibiting not only improved recognition ability but also dual-visual signal, with turn-on red luminescence and high-contrast color change from pale-yellow to orange-red. The probe also shows excellent selectivity and anti-interference properties, fast response rate (< 1 s) and low detection limit, stretching to 20.6 fg when incorporated in a hydrogel matrix. Structure insight for the dual-visual response shows that this high detection performance derives from the ancillary ligand of -NCS, which endows the increase of ion-association ability between platinum(II) terpyridyl complex and [HgCl4]2−, leading that 1D packing mode with strengthened Pt-Pt interactions. In all, this work highlights a new strategy of 1D supramolecular assembly construction for high performance detection of heavy metal ions.

Rationale and Design of OPT-RATE AF: A Randomized Clinical Trial of Increased Physiologic Pacing Rates in Heart Failure With Preserved Ejection Fraction

Cardiac physiologic pacing (CPP) after atrioventricular node (AVN) ablation for persistent atrial fibrillation (AF) has improved outcomes in patients with heart failure with reduced and preserved ejection fraction (HFpEF). Emerging evidence suggests patients with HFpEF benefit from higher heart rates, yet the optimal pacing rate after AVN ablation remains unknown. OPT-RATE AF is a prospective, randomized crossover study of patients with HFpEF following AVN ablation for persistent AF (NCT06445439). Approximately 60 patients with AF and AVN ablation, CPP, and HF with left ventricular ejection fraction ≥50% will be enrolled. Participants will be randomly assigned 1:1 to a pacing lower rate limit of 60 beats-per-minute (bpm) for 3 months and then switched to a rate of 80 bpm for 3 months, and vice versa. The primary endpoint is change in exercise capacity assessed by the 6-minute walk test. Notable secondary outcomes will include change in Kansas City Quality of Life Questionnaire (KCCQ-12), creatinine and natriuretic peptide, and clinical events. Patient mortality and HF hospitalizations will be recorded at each phase. EKG, echocardiogram, pacemaker interrogation, and primary and secondary outcomes will be recorded at baseline, 3 months, and 6 months. Study enrollment is ongoing and estimated to be completed by 2026. OPT-RATE AF is a randomized clinical trial that will determine the effect of a higher pacing rate in patients with persistent AF and HFpEF following AVN ablation and/or CPP. Study findings will provide insight on the role of chronotropy in improving QoL and other important cardiovascular outcomes.

Experimental and modeling studies on char combustion under pressurized O2/H2O conditions

The desorption kinetic parameters for pressurized combustion and gasification reactions were determined based on a C++ program coupled with the Langmuir-Hinshelwood (L-H) kinetic model developed and experimental data from pressurized char combustion, and the established L-H kinetic model for pressurized char-O2/H2O combustion was refined in the current paper. The activation energy for desorption in reactions involving pressurized char-O2 and char-H2O was determined to be 250.8 kJ/mol, accompanied by a pre-exponential factor of 5.42 × 1010 g/(m2 s). Using this foundation, the current research conducted simulations to investigate the impacts of temperature, pressure, and H2O concentration on the oxidation adsorption rate (Rads,oxi), desorption rate (Rdes), gasification adsorption rate (Rads,gas), and the competitive influences of kinetics and diffusion processes within the pressurized char-O2/H2O combustion. The simulation results indicate a gradual increase in Rdes and Rads,gas with char conversion to reach a peak, followed by a gradual decline. Conversely, the Rads,oxi varies smoothly throughout the char conversion process. At 1673 K/1.0 MPa, the char-O2/H2O reaction rate is primarily constrained by Rads,oxi and Rads,gas, with the adsorption reaction serving as the rate-controlling step. Moreover, it was noted that a rise in pressure resulted in a linear increase in Rads,oxi, Rdes, and Rads,gas. At elevated temperatures, the impact of pressure on them becomes more noticeable. However, the introduction of H2O mitigates this effect. Elevated temperature and pressure facilitate the competition on the kinetics of char-O2 combustion for O2 diffusion, resulting in the conversion of char being more susceptible to O2 diffusion rate limitation. With the addition of 20 % H2O, the competition effect was weakened. In the case of pressurized combustion involving char and O2/H2O, the char conversion is primarily constrained by the O2 diffusion rate and is scarcely influenced by the H2O diffusion rate.