Steep Curve Research Articles

Numerical simulation of temperature distribution and residual stress in TIG welding of stainless-steel single-pass flange butt joint using finite element analysis

Abstract Controlling defects such as deformation in the weld joint and the residual or superfluous stresses due to tungsten inert gas (TIG) welding or arc welding is a major concern for many industries like aeronautical, automobiles, nuclear or atomic power plants, crude oil or fossil fuel industries where pipes are in use and circumferential welding is done. Arc welding is a metal joining process, and TIG welding is applied to many industrial sectors that require high-quality welding. Simulation has been done on single-pass TIG welding on the Flange pipe of SS316 to evaluate transient temperature, residual stresses, and distortion. First, a 3D model is developed and assembled in SolidWorks. Second, in an MSC Patran, preprocessing of the FE model is done. Finally, in MSC Marc, thermal and mechanical simulation is performed. Based on this simulation, the accuracy of welding of the flange–butt joint made of SS316 is validated. In this study, the information regarding simulation of temperature dispensation and residual or superfluous stresses is done on the flange–butt joint, and it found the stresses are compressive at the weld bead area, and along the transverse direction, stresses changed to the tensile. The experimental data show that the steep curve at 0.00 mm represents a maximum temperature near the weld path at approximately 2,352°C, and the slant curve shows the far away points from the weld path. Comparing it with FE analysis, the maximum temperature attained was around 2,539°C. An approximate deviation of 7.365% was observed. The results of the study will provide experimental and simulation analyses for the welding of pipes of stainless steel for the transportation of oil and gases in the petroleum industries.

Low-dose lung CT: Optimizing diagnostic radiation dose – A phantom study

Background/purposeTo investigate a quantitative method for assessing image quality of low dose lung computed tomography (CT) and find the lowest exposure dose providing diagnostic images. MethodsAxial volumetric lung CT acquisitions (256 slice scanner) were performed on three different sized anthropomorphic phantoms at different dose levels. The maximum steepness of sigmoid curves fitted to line density profiles was measured at lung-to-pleura interfaces. For each phantom, image sharpness was calculated as the median of 468 measurements from 39 different locations. Diagnostic image quality for the adult and paediatric phantom was rated by three radiologists using 4-point Likert scales. The image sharpness cut-off for obtaining adequate image quality was determined from qualitative ratings. ResultsAdequate diagnostic image quality was reached at a median steepness of 713 HU/mm in the adult phantom with a corresponding CTDIvol of 0.14 mGy and an effective dose of 0.13 mSv at a dose level of 100 kVp and 10 mA. In the paediatric phantom diagnostic image quality was reached at a median steepness of 1139 HU/mm with a corresponding CTDIvol of 0.13 mGy and an effective dose of 0.08 mSv at a dose level of 100 kVp and 10 mA. ConclusionsDetermination of image sharpness on line density profiles can be used as quantitative measure for image quality of lung CT. Sufficient-quality lung CT can be achieved at effective radiation doses of 0.13 mSv (adult phantom) and 0.08 mSv (paediatric phantom). These findings suggest that substantial dose reduction is feasible without compromising diagnostic accuracy.

California Mortality and the Healthy Places Index.

We investigated California mortality and social determinants of health, as measured by the Healthy Places Index (HPI), which is a composite measure of 23 indicators of neighborhood (census tract) economic conditions, education, transportation, housing, social capital, environmental pollution, built-environment, and access to health care. We aggregated deaths to 2010 census tract boundaries for leading causes, 2015 to 2019, and COVID-19, 2020-2021, from death certificates and populations from the American Community Survey, 2015 to 2019. We age-adjusted and stratified death rates by HPI deciles, age, gender, and race/ethnicity, and examined HPI dose-response with segmental regression. For all causes, cancer, cardiovascular disease, COVID-19, diabetes, cirrhosis of the liver, injuries, and Alzheimer's disease (ages 65-74 years), mortality rates were inversely related to HPI decile. For all causes mortality, the rate ratio between the 1st and 10th decile (reference) was 1.63 (CI95%: 1.60-1.66), and, for COVID-19, the rate ratio was 7.61 (CI95%: 7.14-8.12). The population attributable fraction was 24% for all causes and 72% for COVID-19. Age, gender, race/ethnicity modified the steepness and shape of dose-response curves. The findings illustrate opportunities to incorporate area-based socioeconomic measures in routine public health surveillance, and to reinforce policies and programs that reduce health inequities.

A Survey of Dynamical and Gravitational Lensing Tests in Scale Invariance: The Fall of Dark Matter?

We first briefly review the adventure of scale invariance in physics, from Galileo Galilei, Weyl, Einstein, and Feynman to the revival by Dirac (1973) and Canuto et al. (1977). In the way that the geometry of space–time can be described by the coefficients gμν, a gauging condition given by a scale factor λ(xμ) is needed to express the scaling. In general relativity (GR), λ=1. The “Large Number Hypothesis” was taken by Dirac and by Canuto et al. to fix λ. The condition that the macroscopic empty space is scale-invariant was further preferred (Maeder 2017a), the resulting gauge is also supported by an action principle. Cosmological equations and a modified Newton equation were then derived. In short, except in extremely low density regions, the scale-invariant effects are largely dominated by Newtonian effects. However, their cumulative effects may still play a significant role in cosmic evolution. The theory contains no “adjustment parameter”. In this work, we gather concrete observational evidence that scale-invariant effects are present and measurable in astronomical objects spanning a vast range of masses (0.5 M⊙< M <1014M⊙) and an equally impressive range of spatial scales (0.01 pc < r < 1 Gpc). Scale invariance accounts for the observed excess in velocity in galaxy clusters with respect to the visible mass, the relatively flat/small slope of rotation curves in local galaxies, the observed steep rotation curves of high-redshift galaxies, and the excess of velocity in wide binary stars with separations above 3000 kau found in Gaia DR3. Last but not least, we investigate the effect of scale invariance on gravitational lensing. We show that scale invariance does not affect the geodesics of light rays as they pass in the vicinity of a massive galaxy. However, scale-invariant effects do change the inferred mass-to-light ratio of lens galaxies as compared to GR. As a result, the discrepancies seen in GR between the total lensing mass of galaxies and their stellar mass from photometry may be accounted for. This holds true both for lenses at high redshift like JWST-ER1 and at low redshift like in the SLACS sample. Of note is that none of the above observational tests require dark matter or any adjustable parameter to tweak the theory at any given mass or spatial scale.

Signs of hyperpathia in chronic peripheral neuropathic pain.

Neuropathic pain is pain due to a disease or lesion of the somatosensory system, and can be either spontaneous, evoked or both. Hyperpathia is a type of evoked pain defined by IASP as 'a painful syndrome characterized by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold'. The literature is sparse, and definitions are unclear and inconsistent. The aim of this study was to examine for the presence of mechanical hyperpathia in a heterogeneous group of patients with peripheral neuropathic pain and correlate signs of hyperpathia with other sensory signs. Patients were examined with graded pinprick stimuli to obtain a stimulus-response curve and repetitive pinprick stimuli to assess increase in pain over time and aftersensations. Then, patients were grouped based on the likelihood of having mechanical hyperpathia with either a steep stimulus-response curve or a steep curve on the repetitive pinprick test and results were correlated to mechanical detection and pain thresholds and other outcomes from a full quantitative sensory testing. We included 124 patients with documented peripheral neuropathic pain. Patients with a steep stimulus-response curve did not overlap with patients with a steep curve on the repetitive pinprick test and both groups more often had decreased rather than increased detection and pain thresholds. Our study questions the concept of hyperpathia and suggests that more studies are needed to identify which symptoms and signs group together and might form a syndrome. Hyperpathia is a syndrome of evoked pain. It is poorly defined and little is known about its clinical presentation. Since it is part of pain symptomatology it is important to have a clear definition and understand the pathophysiology behind. This study explored signs of hyperpathia in a heterogeneous group of patients with peripheral neuropathic pain. We used stimulus-response function and repetitive pinprick stimulation to group patients based on the IASP definition. More studies are needed to understand how symptoms and signs coincide.

Can the digital economy empower the transportation sector to improve green total factor productivity?

The digital economy has the potential to facilitate digitization and green transformation within the transportation sector, but further research is warranted on how it can enhance the sector’s green total factor productivity (GTFP). Utilizing provincial data from China spanning 2013 to 2021, this study investigates the impact of the digital economy on the transportation sector’s GTFP. The findings are as follows: (1) The transportation sector exhibits a U-shaped relationship between the digital economy and GTFP. The inflection point of the U-shaped curve is at 0.441, with 81.11% of the samples falling to the left of this point. It is primarily through technological progress and innovation, rather than changes in technological efficiency, that the digital economy influences the improvement of GTFP. (2) The U-shaped relationship exhibits heterogeneity and varies depending on the mode and content of transportation. The U-shaped relationship is more pronounced in regions with lower total traffic volume on highways and railways or higher traffic volume on waterways. For transportation content, DEEI and GTFP show a significant U-shaped relationship in areas with high traffic volumes of passengers and freights. (3) Government intervention can attenuate the U-shaped relationship, which leads to a flatter curve. The market-driven level has the capability to strengthen the U-shaped relationship, resulting in a steeper curve. In conclusion, these findings contribute to deeper insights into the U-shaped relationship between the digital economy and GTFP, offering valuable guidance for policymakers seeking to improve GTFP in the transportation sector.

Accurate Measurement of the Lensing Magnification by BOSS CMASS Galaxies and Its Implications for Cosmology and Dark Matter

Magnification serves as an independent and complementary gravitational lensing measurement to shear. We develop a novel method to achieve an accurate and robust magnification measurement around BOSS CMASS galaxies across physical scales of 0.016h −1 Mpc < r p < 10h −1 Mpc. We first measure the excess total flux density δ M of the source galaxies in the deep DECaLS photometric catalog that are lensed by CMASS galaxies. We convert δ M to magnification μ by establishing the δ μ–δ M relation using a deeper photometric sample. By comparing magnification measurements in three optical bands (grz), we constrain the dust attenuation curve and its radial distribution, discovering a steep attenuation curve in the circumgalactic medium of CMASS galaxies. We further compare dust-corrected magnification measurements to model predictions from high-resolution dark matter-only (DMO) simulations in Wilkinson Microwave Anisotropy Probe (WMAP) and Planck cosmologies, as well as the hydrodynamic simulation TNG300-1, using precise galaxy–halo connections from the Photometric objects Around Cosmic webs method and the accurate ray-tracing algorithm P3MLens. For r p > 70h −1 kpc, our magnification measurements are in good agreement with both WMAP and Planck cosmologies, resulting in an estimation of the matter fluctuation amplitude of S 8 = 0.816 ± 0.024. However, at r p < 70h −1 kpc, we observe an excess magnification signal, which is higher than the DMO model in Planck cosmology at 2.8σ and would be exacerbated if significant baryon feedback is included. Implications of the potential small scale discrepancy for the nature of dark matter and for the processes governing galaxy formation are discussed.

Evidence for gravitational self-lensing of the central supermassive black hole binary in the Seyfert galaxy NGC 1566

It is generally accepted that all massive galaxies host supermassive black holes (BHs) in their center and that mergers of two galaxies lead to the formation of BH binaries. The most interesting among them comprise the mergers in their final state, that is to say\ with parsec (3.2 light years) or sub-parsec orbital separations. It is possible to detect these systems with binary self-lensing. Here we report the potential detection of a central supermassive BH binary in the active galaxy (AGN) NGC\,1566 based on a microlensing outburst. The light curve of the outburst -- based on observations with the All Sky Automated Survey for SuperNovae -- lasted from the beginning of 2017 until the beginning of 2020. The steep symmetric light curve as well as its shape look very different with respect to normal random variations in AGN. However, the observations could be easily reproduced with a best-fit standard microlensing light curve. Based on the light curve, we derived a characteristic timescale of 155 days. During the outburst, the continuum as well as the broad line intensities varied; however, the narrow emission lines did not. This is an indication that the lensing object orbits the AGN nucleus between the broad line region (BLR) and the narrow line region (NLR), that is, at a distance on the order of 250 light days. The light curve can be reproduced by a lens with a BH mass of $5 M_ odot $. This implies a mass ratio to the central AGN on the order of 1 to 10.

Study on the design method of multi-component industrial solid waste low carbon cementitious material with cement as the activator

The relationship between microstructure and mechanical properties of multi-component solid waste low-carbon cementitious materials has been widely pay attention to. However, industrial solid waste is a complex multi-component system with many variable factors, which makes it difficult to design the formulation of cementitious materials. This paper pioneered the application of machine learning (ML) models, algorithms and error rates to analyze the compressive and flexural strength of fly ash-based pastes. Coefficient of determination (R2), mean squared error (MSE), root mean square error (RMSE), mean absolute error (MAE) and a20-index were used to evaluate robustness. X-ray diffraction (XRD), scanning electron microscope (SEM) and Brunauer-Emmett-Taylor (BET) were carried out to analyze evolution of cementitious materials. The evaluation results of ML models exhibited that the Gradient boosting regression (GBR) model had the best determination parameters and a steep normal distribution fitting curve with an a20-index of 0.861. GBR model exhibited the best robustness. The key factors of fly ash-based cementitious materials were identified by Pearson's coefficient, which was benefit to determine the formulation of multi-component solid waste low-carbon cementitious materials. Furthermore, experiments also demonstrated that the optimum ratio of multi-component solid waste low carbon cementitious material was 10 % gypsum, 10 % metakaolin, 45 % fly ash, 15 % slag and 20 % cement, respectively. It was worth noting that the compressive strength of this kind of multi-component solid waste low-carbon cementitious materials reached 35 MPa, which was superior to the mechanical properties of P·O 32.5 cement. The results of phase, SEM images and pore structure distribution showed that the synergistic effect of the multi-component solid waste materials effectively filled the material voids and also facilitated the formation of a variety of gelatinous materials through gelling reactions in the late stage (14–28 d). This work will promote the resource utilization of industrial solid waste, contribute to carbon reduction, and can accelerate the green revolution of concrete.

#1463 Assessment of salt-sensitive hypertension in a novel Lanosterol Synthase knock-in mouse model

Abstract Background and Aims The diversity in blood pressure (BP) response to various salt intakes, known as Salt Sensitivity (SS), exhibits significant differences among individuals within the hypertensive subjects relative to the general population. Hypertension (HT) and SS are correlated to elevated levels of plasma Endogenous Ouabain (EO). We aimed at delineating the role of the missense variation rs2254524 (Val642Leu; C&amp;gt;A) within the Lanosterol Synthase gene (LSS), encoding for an enzyme involved in steroid biosynthesis. Individuals with the AA LSS variant, adherent to a low-salt diet, had a more significant BP reduction compared to those with CC genotype. Method Utilising CRISPR-Cas9, we established a knock-in mouse model carrying the analogous LssV643L/V643L. Male mice were subjected to a normal-salt diet (0.5% NaCl), high-salt diet (4% NaCl), or low-salt diet (&amp;lt;0.03% Na) and BP was monitored every two days using a tail-cuff system for 10 days. Blood and urine were collected separately in metabolic cages. Results Homozygous mice for Lss mutation demonstrated normal viability and healthy phenotype, undistinguishable from the WT. At baseline, the Lss AA mice were affected by a significant augmentation in kidney weight at 3 and 12 months of age, relative to WT. The Lss V643L does not influence EO levels or systolic BP (SBP), specifically at 3 and 12 months, but affects the SBP response to dietary salt. AA mice showed a high SBP in a high-salt diet against control diet at the same time intervals. Moreover, the Lss variant impacted the pressure-natriuresis relationship, with the mutated AA strain showing a less steep curve both in control diet versus the high-salt diet and in control diet versus the low-salt diet, displaying the SS phenotype of the AA mice. The 12-month-old mice in high-salt diet displayed cardiac hypertrophy with the AA genotype exhibiting an elevated prevalence of cardiac fibrosis. The level of Lss mRNA decreased in the adrenal glands in response to a high-salt diet. RNASeq analysis identified distinct patterns in several Slc genes, Cbr2 and Arhgap26 within the kidneys of these mice, in control or high-salt dietary conditions. Conclusion The established LssV643L/V643L mouse model effectively mirrors the SS-HT phenotype. Our findings highlight the significance of the Lss in modulating BP in response to salt stimuli suggesting a potential organ damage pathway requiring further exploration in older mice.

Near-term forward rate spread and commodity index relationship with real economic activity in Brazil

This study investigates the relationship between Brazilian economic cycles and two key indicators: the international S&P GSCI commodity index and the near-term forward spread derived from the Brazilian interest rate term structure. We find that the forward spread serves as a robust leading indicator of economic downturns in Brazil, offering recession forecasts up to four quarters in advance. This underscores a link between yield curve steepness and recession likelihood in Brazil. However, we uncover distinct cyclical behaviors in Brazil's term structure that diverge from patterns in the United States. Furthermore, our research reveals the significant influence of commodity price fluctuations on Brazil's economic performance, underscoring a strong correlation between commodity markets and economic outcomes. Examining term structure and commodity prices together provides novel insights into monitoring emerging market cycles. These indicators can assist policymakers and improve early warning systems, especially in developing economies like Brazil.

Low-power and robust ternary SRAM cell with improved noise margin in CNTFET technology

In this paper, a carbon nanotube field-effect transistor (CNTFET) based low power and robust ternary SRAM (TSRAM) cell with enhanced static noise margin (SNM) has been proposed. The proposed cell uses a low-power cell core and a stack of 2 CNTFETs to discharge the read bit line (RBL) to ground, unlike the previous SRAM designs which use read buffers or transmission gates (TG) to alter the voltage levels on the RBL. The proposed TSRAM cell has been simulated relentlessly, using the Stanford 32 nm CNTFET technology mode file with Synopsis HSPICE tool under various operating conditions. Unlike other designs, the cross-coupled ternary inverters used as the cell core in the proposed TSRAM show higher gain and steep curves in the transition region mitigating the static power of the cell. The simulation results exhibit improvements in performance parameters like power consumption, energy, noise margins, and reliability. At 0.9 V supply voltage, the proposed TSRAM cell offers 52.44% and 43.17% reduction in write and read static power, a PDP reduction of 35.29% in comparison, and a 36.36% improvement in SNM compared to the best designs under investigation. Also, the proposed TSRAM design shows higher robustness compared to other designs.

Synthesis and Crystallization Mechanism for SAPO-34 Zeolite Derived from Magadiite.

In this work, we explored the hydrothermal synthesize and crystallization process of SAPO-34 zeolites from two-dimensional layered silicate magadiite by using tetraethylammonium hydroxide (TEAOH) as a templating agent. Comprehensive characterization was conducted by XRD, SEM, FTIR, Raman, and BET. Time-resolved PXRD analysis revealed that SAPO-34 zeolite exhibited a steep growth curve when the crystallization time was 30 h, and the crystallinity reached 98.65 % at 48 h. Specifically, the disruption of the magadiite layer exposed charged silanol groups on the surface, fostering an affinity for AlO4 and PO4 species, thereby initiating the nucleation process. Under the guidance of TEAOH, these nucleation sites transformed into SAPO-34 nuclei, gradually advancing towards crystallization. FTIR and Raman analyses affirmed the presence of 6Rs, followed by D6R and 4Rs SBUs, along with the characteristic CHA structure. Combined with 29Si NMR established that disaggregated silicate minerals served as zeolite synthesis "seeds", enhancing nucleation sites and overall crystallization efficiency.

Long-term stability of curve of Spee depth among orthodontically treated patients: A retrospective longitudinal study.

The curve of Spee is deemed important characteristic of the dentition for a balanced occlusion and distribution of masticatory forces, while orthodontic levelling of an accentuated curve of Spee is generally included as a treatment goal for deepbite correction. However, relapse is often seen and can be problematic. A retrospective longitudinal study of predominantly young patients with a deep curve of Spee, who had been treated orthodontically with 0.018"-slot Edgewise fixed appliances, was performed. The depth of the curve of Spee was digitally measured before treatment (T1), at debond (T2), and an average of 7 years post-debond (T3) and analysed statistically at 5%. A total of 157 patients were included (56.7% female; 11.6-year-old at T1), 16.6% of which were treated with premolars extractions. Non-extraction treatment reduced the curve of Spee at the first premolar from 1.87 mm (T1) to 0.22 mm (T2), which relapsed 0.12 mm (T3; P = .04). The respective depths for the second premolar were 2.0 mm (T1), reduced to 0.80 mm (T2). No significant relapse was seen for the second premolar (0.08 mm; P > .05) or the first permanent molar (0.06 mm; P > .05). No overall significant differences in absolute relapse were seen between extraction and non-extraction patients, but premolar extractions were associated with less clinically relevant relapse at the first molar (odds ratio 0.27; 95%-confidence interval 0.08-0.88; P = .003). Steep curves of Spee can be satisfactorily levelled orthodontically with satisfactory stability in the long term, while premolar extractions might be associated with less relapse.

Toward an Adjustable Blood Pump for Wide-Range Operation: In-Vitro Results of Performance Curve and Hydraulic Efficiency.

Rotary blood pumps in Extracorporeal Life Support (ECLS) applications are optimized for a specific design point. However, in clinical practice, these pumps are usually applied over a wide range of operation points. Studies have shown that a deviation from the design point in a rotary blood pump leads to an unexpected rise of hemolysis with corresponding clinical complications. Adjustable pumps that can adapt geometric parameters to the respective operation point are commonly used in other industrial branches, but yet not applied in blood pumps. We present a novel mechanism to adjust the impeller geometry of a centrifugal blood pump during operation together with in-vitro data of its hydraulic performance and efficiency. Three-dimensionalprinted prototypes of the adjustable impeller and a rigid impeller were manufactured and hydraulic performance and efficiency measured (n = 3). In a flow range of 1.5-9.5 L/min, the adjustable pump increased pump performance up to 47% and hydraulic efficiency by an average of 7.3 percentage points compared with a fixed setting. The adjustable pump allows customization of the pump's behavior (steepness of performance curve) according to individual needs. Furthermore, the hydraulic efficiency of the pump could be maintained at a high level throughout the complete flow range.

High fluence in laser stapedotomy aggravates transient subjective dizziness

Background Laser fenestration in stapedotomy has thermal effect to the vestibule. Aims/Objectives To evaluate the role of energy density (fluence) in the severity of postoperative vestibular symptoms. Materials and methods The retrospective chart-review study included 84 patients with otosclerosis that underwent primary laser stapedotomy. Surgical outcomes, including nystagmus, and subjective vestibular symptoms during one-month follow-up, were compared between potassium titanyl phosphate (KTP) and CO2 laser. According to this study and literature, we assessed the relationship between laser parameters and the incidence of persistent vestibular symptoms lasting more than one week after surgery. Results The KTP and CO2 laser group included 48 and 36 patients, respectively. Fluence was different between the KTP (637 J/cm2) and CO2 (141 J/cm2) laser (p < .001). The KTP group showed gradual decrease in dizziness during one-month observation period, while the CO2 group exhibited a steep recovery curve in the first postoperative week (9 and 4 d of duration, respectively). The incidence of persistent vestibular symptoms was correlated with both fluence (r = 0.80, p = .01) and spot size (r = −0.74, p = .01). Conclusions and significance Appropriate setting of parameters with lower fluence is desirable for the efficiency and safety of laser stapedotomy. Abbreviations: ABG: air-bone gap; SD: standard deviation.

Relationship between SMEs’ ESG performance and value creation in China: the moderating role of government subsidies

This paper uses Chinese small and medium enterprises (SMEs) as a research sample to explore the relationship between environment, social responsibility, governance (ESG) performance and firm value creation and to test the moderating effect of government subsidies. In addition, we classify government subsidies into innovation, social responsibility, and development subsidies using a Biterm Topic Model (BTM) to explore the heterogeneous moderating effects. The results show an inverted U-shaped relationship between ESG performance and value creation in Chinese SMEs. Government subsidies have a significant moderating effect on the inverted U-shaped curve of ESG performance and value creation, and the moderating effect of different government subsidies also varies. An increase in social responsibility subsidies makes the curve inflection point shift to the left, an increase in development subsidies makes the inflection point shift to the right and the curve steeper, and innovation subsidies have no moderating effect.

Polarization and single-pulse micro-structure studies of Rotating Radio Transient J0139+3336 with FAST

ABSTRACT The study of polarization and micro-structure is very important for understanding the radiation mechanism of Rotating Radio Transients (RRATs). Due to the limitations of telescope sensitivity and time resolution, studies of the polarization and micro-structure of RRATs have been rare in the past. In this work, we report on a high-time resolution and full polarization observation of RRAT J0139+3336 with the Five-hundred-meter Aperture Spherical Radio Telescope (FAST). A total of 96 burst pulses were detected in the 3-h observation. The degrees of linear and circular polarization and the shape of the polarization position angle (PPA) of the single pulses vary significantly. The average profile displays a small degree of linear and circular polarization, and the PPA exhibits a remarkably smooth and steep S-shaped curve, which are also characteristics of pulsars. The circular polarization in some single pulses demonstrates a clear sign change. We discuss the geometric structure of the emission beam based on the results from fitting the RVM model to the changes in the PPA. Using an autocorrelation analysis, the quasi-periodic micro-structure in the single pulse emission is detected with a median period of about 0.91 ms. We show that the position of RRAT J0139+3336 on the P–Pμ diagram falls in the normal pulsar (NP) region . The radio emission of RRAT J0139+3336 shows unique properties, such as the sign change in the circular polarization and quasi-periodicity in the micro-structure, which will provide important clues to the emission mechanism of RRATs.

Revenue-optimized photovoltaic orientation in a northern competitive electricity market with carbon offsets

Solar photovoltaic (PV) farms are typically designed to maximize energy generation; however, their impacts on market prices can create conditions where revenues may be maximized by orienting the system to produce more energy at more valuable times of the day. PV generation offers its energy at a zero-dollar price in competitive electric markets, which tends to result in a drop in hourly price (“merit-order effect”) and reduction of revenues (“cannibalization effect"). We present an analysis of optimizing the orientation of PV systems for revenues, accounting for cannibalization in three pricing dynamics, with flat, medium, and steep merit-order curves. We employ a dataset of historical price-quantity offers from 2011 to 2019 from Alberta, Canada, a market that also has significant opportunities to generate carbon credits (CC). The market has an average maximum hourly load of ∼9 GW; we introduced 15, 400, 1000, and 3000 MW PV-capacity inputs, using tilt angles from 0° to 90° and azimuths from 90° to 270°. Our results show that for small PV capacities compared to the load, the market revenue-optimized orientations are close to the energy-optimized orientations, as would be expected. At higher levels of PV capacity, market revenue-optimized orientations deviate from the energy-optimized orientation as price cannibalization increases. The extent of this deviation depends on the slope of the historical merit order. When CC are introduced into the simulation, the total revenue-optimized orientation moves back towards the energy-optimized orientation as the CC overcome cannibalized market losses but exasperate overall market price depression.

Cannabidiol Modulates M-Type K+ and Hyperpolarization-Activated Cation Currents.

Cannabidiol (CBD) is a naturally occurring compound found in the Cannabis plant that is known for its potential therapeutic effects. However, its impact on membrane ionic currents remains a topic of debate. This study aimed to investigate how CBD modifies various types of ionic currents in pituitary GH3 cells. Results showed that exposure to CBD led to a concentration-dependent decrease in M-type K+ currents (IK(M)), with an IC50 of 3.6 μM, and caused the quasi-steady-state activation curve of the current to shift to a more depolarized potential with no changes in the curve's steepness. The CBD-mediated block of IK(M) was not reversed by naloxone, suggesting that it was not mediated by opioid receptors. The IK(M) elicited by pulse-train stimulation was also decreased upon exposure to CBD. The magnitude of erg-mediated K+ currents was slightly reduced by adding CBD (10 μM), while the density of voltage-gated Na+ currents elicited by a short depolarizing pulse was not affected by it. Additionally, CBD decreased the magnitude of hyperpolarization-activated cation currents (Ih) with an IC50 of 3.3 μM, and the decrease was reversed by oxaliplatin. The quasi-steady-state activation curve of Ih was shifted in the leftward direction with no changes in the slope factor of the curve. CBD also diminished the strength of voltage-dependent hysteresis on Ih elicited by upright isosceles-triangular ramp voltage. Collectively, these findings suggest that CBD's modification of ionic currents presented herein is independent of cannabinoid or opioid receptors and may exert a significant impact on the functional activities of excitable cells occurring in vitro or in vivo.