Unusual Pressure Research Articles

An Unusual Hemodynamic Pressure Trace Mimicking Aortic Stenosis: A Decepti "Con".

We report an abnormal hemodynamic pressure tracing taken during pullback from the left ventricle. This report emphasizes the careful observation of hemodynamic tracing relative to continuous electrocardiographic monitoring for identifying potentially pathological vascular phenomena that may have detrimental outcomes on the clinical management of the underlying condition.

Ti(III) Catalysts for CO2/Epoxide Copolymerization at Unusual Ambient Pressure Conditions.

Titanium compounds in low oxidation states are highly reducing species and hence powerful tools for the functionalization of small molecules. However, their potential has not yet been fully realized because harnessing these highly reactive complexes for productive reactivity is generally challenging. Advancing this field, herein we provide a detailed route for the formation of titanium(III) orthophenylendiamido (PDA) species using [LiBHEt3] as a reducing agent. Initially, the corresponding lithium PDA compounds [Li2(ArPDA)(thf)3] (Ar = 2,4,6-trimethylphenyl (MesPDA), 2,6-diisopropylphenyl (iPrPDA)) are combined with [TiCl4(thf)2] to form the heterobimetallic complexes [{TiCl(ArPDA)}(μ-ArPDA){Li(thf)n}] (n = 1, Ar = iPr 3 and n = 2, Ar = Mes 4). Compound 4 evolves to species [Ti(MesPDA)2] (6) via thermal treatment. In contrast, the transformation of 3 into [Ti(iPrPDA)2] (5) only occurs in the presence of [LiNMe2], through a lithium-assisted process, as revealed by density functional theory (DFT). Finally, the Ti(IV) compounds 3-6 react with [LiBHEt3] to give rise to the Ti(III) species [Li(thf)4][Ti(ArPDA)2] (Ar = iPr 8, Mes 9). These low-valent compounds in combination with [PPN]Cl (PPN = bis(triphenylphosphine)iminium) are proved to be highly selective catalysts for the copolymerization of CO2 and cyclohexene epoxide. Reactions occur at 1 bar pressure with activity/selectivity levels similar to Salen-Cr(III) compounds.

Graviton Momentum: A Natural Source of Dark Energy

The dark energy concept in the standard cosmological model can explain the expansion of the universe. However, the mysteries surrounding dark energy remain, such as its source, its unusual negative pressure, its long-range force, and its unchanged density as the universe expands. We propose a graviton momentum hypothesis, develop a semiclassical model of gravitons, and explain the pervasive dark matter and accelerating universe. The graviton momentum hypothesis is incorporated into the standard model and explains well the mysteries related to dark energy.

Initial observation of the urodynamic pressure flow study — characteristics of bladder-neck or prostate median lobe dynamics during micturition

Purpose:We present our observations of a urodynamic pressure flow study graph pattern that may be associated with bladder neck hypertrophy or prostate median lobe enlargement. Materials and Methods:We report 23 male patients with signs and symptoms of lower urinary tract dysfunction who underwent urodynamic testing with pressure flow study analysis. We recognized an unusual pressure flow plot curve and found that these patients had cystoscopic evidence for bladder neck hypertrophy or cystoscopic or ultrasound evidence for prostate median lobe enlargement. Results:The patients here demonstrated showed a pattern of increasing detrusor pressure on the pressure flow study — graph phase after maximum of flowrate, where a decreasing pressure pattern is expected. We contemplated that his pattern may show how bladder outflow dynamics is affected by the anatomical features of these patients and how patients may have symptoms of LUT dysfunction or significant residual urine despite a relatively good maximum flow rate. Conclusion:We present a not previously described variation of the pressure flow study graph pattern common in men with prostatic hyperplasia, in a series of patients with median lobe prostatic hyperplasia and or hypertrophy of the bladder neck.

A Case of Large Cervical Leiomyoma

Uterine Leiomyoma or Myoma or commonly favorite named Fibroid is a most common entity of genital organ tumor. It isalmost benign tumor of smooth muscle origin where smooth muscle fiber and fibrous connective tissue intermingled togetheroften found in uterus. Although it is a disease of nulliparous but in perspective of our country it diagnosed in patient's havingone or two child because of early marrital status. Tumor varies in number 1-200 and also varies different clinical features andseverity depending site of presentation. Leiomyoma is generally slowly progressive disease but sometimes it grows veryrapidly. With the advent of Ultrasonography it is incidentally diagnosed often with asymptomatic cases. UsuallyUltrasonography is the single most predictor of investigation1 from very early cases although MRI is helpful. Asymptomatic large Fibroid present with various unusual symptoms like pressure symptom of surrounding structure or feelingof heaviness of lower abdomen or fullness of abdomen. Large cervical Fibroid is a uncommon presentation with mainly urinarydifficulties where patients chief complaints is frequent micturation and incomplete voiding of urine without significantmenstrual abnormalities. The described cases for urinary complain patient consulted with urologist and referred as a largecervical Fibroid diagnosed by sonography. This article illustrates a case of 34 years old lady present with frequent micturationand incomplete voiding of urine that developed last 5-6 months duration. Total abdominal hysterectomy performed,histologically the specimen showed benign uterine leiomyoma. Post operative circumstance uneventful evaluation occur andpatient back to home with normal duration hospital stay.

Conversion of obsolete keyboard plastics mixed with egg shells and fly ash into concrete brick cubes

Plastic waste is a menace due to its non-degradable properties and chemical composition. Owing to inefficient recycling methods, around 90% of the E-waste plastics are landfilled every year. Burning of E-waste plastics results into the release of dioxins and furans which create severe environmental threats and health hazards. Several studies have been conducted on the utilization of plastics like soda bottles, plastic bags, etc. comprising of single polymers. However, the sustainable utilization of E-waste plastics is limited because E-waste along with plastics is also comprised of another key ingredients that are critical to recycle. US EPA (2012) study reported that approximately 94% of non-metallic fractions (Plastics) in E-waste are landfilled every year. Also, the plastic in E-waste forms a more complex polymer blend, and hence the initiative toward its safe recycling is limited.This article presents an endeavor towards transforming obsolete keyboard plastics into concrete brick cubes mixed with fly ash and eggshell. FTIR test was conducted to screen the polymers present in E-waste plastics. Qualitative and quantitative tests, such as water absorption, bulk density, compressive strength, hardness, and soundness tests were performed to compare different sets A, B, C, D, and E of the brick cubes. The heavy metals in the plastics were found to be within the permissible limit as per RoHS Standard, US EPA, 1989. The obtained peak of the FTIR test revealed (ABS, TBBA, and PC) polymers which were found to be efficient materials for the preparation of concrete brick cubes. The comprehensive strength (15.25 N/mm2) of brick cube D, comprising keyboard plastic, eggshell, and fly ash as 3.12%, 3.12%, and 6.25%, respectively, was found to be almost similar to the second-class bricks. The experimental approach directs that the conversion of E-waste plastics into concrete brick cubes is a better way to obtrude unusual pressure on the environment.

Zinc Nanoparticles (ZnNPs): High-Fidelity Amelioration in Turnip (Brassica rapa L.) Production under Drought Stress

The detrimental effects of drought have adverse impacts on the crop yield as global climatic changes put unusual pressure on water resources. The challenge of attaining water security is key for the sustainable development of crops. Zinc (Zn2+) is an important nutrient that helps to alleviate drought stress by modulating the growth and yield of crops. Recently, zinc nanoparticles (ZnNPs) have been used as a novel strategy for the fertilization of crops. This study was specifically developed to observe the comparative effects of ZnNPs and conventional zinc sulfate (ZnSO4) at diverse concentration levels (0.01%, 0.05%, and 0.1%) that could effectively decrease the injurious effect of drought stress on turnip plants. In experiments on the golden turnip variety, drought stress caused a significant reduction in all growth and biochemical attributes, and increased antioxidant enzymatic activity. In a comparison with the conventional fertilizer ZnSO4, the foliar application of 0.1% ZnNPs significantly improved plant height, biomass, root/turnip length, turnip diameter, antioxidant defense system, secondary metabolites, and photosynthetic pigments in the leaves under drought stress. Based on the collected results, it is suggested that the foliar application of ZnNPs, instead of ZnSO4, under drought stress is helpful in increasing the growth and yield of turnip plants.

High-Performance Kinetic Hydrate Inhibition with Poly(N-isopropyl methacrylamide) and Triisopentylamine Oxide─Surprising Concentration-Dependent Results

Kinetic hydrate inhibitors (KHIs) are mostly used to prevent the deposition of gas hydrates in gas and condensate production flow lines. The main component in a KHI formulation is a water-soluble polymer, blended with solvents and other synergists to boost the performance. The performance limit in terms of subcooling and other factors restricts the application range of KHIs. Earlier, we reported on the synergetic performance of trialkylamine oxides with polyalkyl(meth)acrylamides using high-pressure steel rocking cell experiments. In particular, blends of poly(N-isopropyl methacrylamide) (PNIPMAm) in isobutyl glycol ether (iBGE) with triisopentylamine oxide (TiPeAO) gave exceptional KHI performance, better than what we have seen for any other KHI blend so far. Therefore, it is important to evaluate the limitations of this KHI. Here, we report the results of the KHI performance of this blend in more detail. The cloud point decreased with increasing salinity (0–15 wt % NaCl), but the blend remained soluble, giving excellent KHI performance even at the highest brine concentration. We also varied the concentration of the PNIPMAm/TiPeAO blend from 250 to 5000 ppm in deionized water in KHI slow constant cooling (SCC) tests using both a natural gas mixture [synthetic natural gas (SNG)] and methane gas. A unique concentration-dependent performance was discovered, wherein the performance decreased greatly above about 1500–2000 ppm, possibly due to aggregation of the polymer and amine oxide. This was observed for SCC tests with both SNG and methane, with the phenomenon being more pronounced for methane. In addition, an unusual double pressure drop was observed in SCC tests with methane and a blend of 5000 ppm PNIPMAm and TiPeAO. This study underlines the fact that overdosing of components in a synergistic blend can sometimes lead to detrimental effects on the KHI performance.

Modeling subsea choke valve erosion with a production-driven shock-associated degradation process

Sand erosion in subsea components can cause serious design and production problems. Choke valves are installed at the wellheads to control the reservoir outflow and protect equipment from unusual pressure fluctuations. They suffer from erosion due to continuous exposure to the abrasive mixture of oil, gas, water, and sand. Severe degradation may cause production slowdown, leading to significant financial losses. Therefore, the capability to predict erosion rates in choke valves given a pre-determined production plan is essential for determining the choke's service life and guaranteeing system integrity. We introduce a productiondriven, shock-associated degradation model to describe the choke valve erosion. The continuous wear is modeled by a Transformed Gamma process, accounting for time- and state-dependent degradation increments. External shocks, i.e., damage caused by sand bursts, are modeled by a compound Poisson process. Both wear and shock process are governed by the production rate that defines the flow velocity inside the pipelines. We derive explicit formulas for the degradation's distribution and introduce an inference procedure based on maximum likelihood estimation. Monte Carlo simulation can be used to estimate the deterioration trend and remaining useful life.

A composite model based on semi-analytical method for multiwell horizontal pad with stimulated reservoir volume

The multiwell horizontal pad is an effective method to enhance oil recovery for unconventional reservoirs. Microseismic evidence indicates that the stimulated reservoir volume (SRV) may have originated in the overlap region created by multi-well fracturing. However, the majority of SRV modeling studies have concentrated on a single well, ignoring the interference from offsetting wells. In this study, a novel model for modeling the SRV and multiwell horizontal pad in unconventional reservoirs is developed using an effective semi-analytical method. The proposed semi-analytical model is capable of simulating the behaviors of a multiwell horizontal pad with an irregularly shaped SRV and an impermeable boundary. The transient pressure behaviors of the multiwell horizontal pad with SRV are significantly different than that of a single isolated well, as demonstrated by the results. The linear flow between wells, the pseudoradial flow (PRF) of the multiwell pad in SRV, the transitional flow, and the final pseudoradial flow (PRF) of the multiwell pad all correspond to an extremely unusual transient pressure response. Due to the high flow capability of SRV, pressure diffusion occurs at a faster rate, resulting in the appearance of these flow regions in advance. Sensitivity analysis confirms that as the scale of SRV increases, the duration of the flow influenced by the SRV increases. The SRV and compensating wells result in a negligible PRF, while the pressure behaviors exhibit a gradual rise. This phenomenon may serve as a demonstration of the extremely rare occurrence of radial flow or PRF in unconventional reservoirs. The horizontal line value for the PRF in SRV is proportional to the total production of the well pad. The horizontal line value for the final PRF is also related to the unstimulated region's mobility ratio, the well pad's production rate and 0.5. The case in Junggar Basin shows that the natural fracture permeability in the SRV is 2.5 mD, the matrix permeability is 0.044 mD, the rectangular SRV side lengths are 1600 m and 880 m, the mobility ratio and dispersion ratio are 15, and the wellbore storage coefficient is 0.5 m3/MPa.

Meteotsunamis reported around Britain and Ireland, and northern France, 18–19 June 2022

Synoptic analysis of the surface pressure and fronts on 19 June 2022, 0000 utc. Unusual tidal movements were reported in Cork Harbour on the south coast of Ireland, and Solva in Pembrokeshire, west Wales on 18 June 2022. Later, unusual surface pressure patterns were observed in parts of eastern England, and on tide gauges at Boulogne-sur-Mer on the French coast early on 19 June.

Thermal Conductivity of BAs under Pressure

AbstractThe thermal conductivity of boron arsenide (BAs) is believed to be influenced by phonon scattering selection rules due to its special phonon dispersion. Compression of BAs leads to significant changes in phonon dispersion, which allows for a test of first principles theories for how phonon dispersion affects three‐ and four‐phonon scattering rates. This study reports the thermal conductivity of BAs from 0 to 30 GPa. Thermal conductivity vs. pressure of BAs is measured by time‐domain thermoreflectance with a diamond anvil cell. In stark contrast to what is typical for nonmetallic crystals, BAs is observed to have a pressure independent thermal conductivity below 30 GPa. The thermal conductivity of nonmetallic crystals typically increases upon compression. The unusual pressure independence of BAs's thermal conductivity shows the important relationship between phonon dispersion properties and three‐ and four‐phonon scattering rates.

Potential Nonstatistical Effects on the Unimolecular Decomposition of H2O2.

An attempt is made to evaluate the nonstatistical effects in the thermal decomposition of hydrogen peroxide (H2O2). Previous experimental studies on this reaction reported an unusual pressure dependence of the rate constant indicating broader falloff behavior than expected from conventional theory. In this work, the possibility that the rate constant is affected by nonstatistical effects is investigated based on classical trajectory calculations on the global potential energy surfaces of H2O2 and H2O2 + Ar. The emphasis is on the intramolecular energy redistribution from the K-rotor, that is, the external rotor for rotation around the principal axis of least moment of inertia. The calculations for the H2O2 molecules excited above the dissociation threshold suggest that the energy redistribution from the torsion and K-rotor to vibrations can be competitive with dissociation. In particular, the slow redistribution of the energy associated with the K-rotor significantly affects the dissociation rate. The successive trajectory calculations for collisions of H2O2 with Ar show that the energy associated with the K-rotor can be collisionally transferred more efficiently than the vibrational energy. On the basis of these results and several assumptions, a simple model is proposed to account for the nonstatistical effects on the pressure-dependent thermal rate constants. The model predicts significant broadening of the falloff curve of the rate constants but still cannot fully explain the experimental data.

Modeling of possible CO2 leakage with phase transition in wellbore-reservoir system based on the Ordos CCS project, China

The leakage of injected CO2 through wellbores, during which the CO2 phase transition may occur, is a prime concern in CO2 deep saline aquifer storage projects. In this study, a two-dimensional non-isothermal wellbore-reservoir coupled model that can deal with the CO2 phase transition is established according to the Shenhua Ordos Carbon Capture and Storage (CCS) project in China. Different leakage scenarios through the injection well are simulated to explore the leakage characteristics and reveal the mechanism of important phenomena. The simulation results show that the CO2 leakage through the injection well in the Ordos CCS project, which takes thick multi-layered strata with unusual pressure distribution as the target reservoir, is self-limited, and the leakage stops after the reservoir pressure is offset with the pressure provided by the leaked groundwater in the wellbore. During the leakage, the liquid-phase or supercritical CO2 in the wellbore-reservoir system undergoes a certain degree of gasification, which has a strong and positive effect on the leakage. Moreover, although the leakage eventually stops at the wellhead, the crossflow between different injection layers through the wellbore continues. The parameter analysis indicates that the permeability and the initial and boundary pressure distribution of the reservoir play an important role in the CO2 leakage process, especially when they have a significant impact on the CO2 gasification in the reservoir. These results may provide a basis for evaluation, precaution, and management of similar wellbore leakage.

Structural, Morphological, Vibrational and Optical Properties of GaN Films Grown by Reactive Sputtering: The Effect of RF Power at Low Working Pressure Limit

This work reports the properties of GaN films grown onto c-Si (100) at relatively low substrate temperature (400°C) by reactive magnetron sputtering. The study depicts the effect of working pressure and RF power on the GaN film structural, vibrational and optical properties characterized by X-ray diffraction, atomic force and scanning electron microscopies, Raman spectroscopy and spectroscopic ellipsometry. Unusual low pressure deposition condition (0.40 Pa) was achieved by using a separated argon inlet directed to the Ga target surface, resulting in improved crystalline quality of the films. In this condition, the preferential crystalline orientation, the surface morphology and the optical gap of the GaN films show a strong dependence on the RF power applied to the Ga target, where low RF power (30-60 W) was responsible for increasing the c-axis orientation and the optical gap, while higher RF power (75-90 W) decreased the overall crystal quality and increased the surface roughness.

Thermodynamic stability of hnRNP A1 low complexity domain revealed by high-pressure NMR.

We have investigated the pressure- and temperature-induced conformational changes associated with the low complexity domain of hnRNP A1, an RNA-binding protein able to phase separate in response to cellular stress. Solution NMR spectra of the hnRNP A1 low-complexity domain fused with protein-G B1 domain were collected from 1 to 2500 bar and from 268 to 290 K. While the GB1 domain shows the typical pressure-induced and cold temperature-induced unfolding expected for small globular domains, the low-complexity domain of hnRNP A1 exhibits unusual pressure and temperature dependences. We observed that the low-complexity domain is pressure sensitive, undergoing a major conformational transition within the prescribed pressure range. Remarkably, this transition has the inverse temperature dependence of a typical folding-unfolding transition. Our results suggest the presence of a low-lying extended and fully solvated state(s) of the low-complexity domain that may play a role in phase separation. This study highlights the exquisite sensitivity of solution NMR spectroscopy to observe subtle conformational changes and illustrates how pressure perturbation can be used to determine the properties of metastable conformational ensembles.

3D Modeling of Suevite Massifs with UHPHT Glasses at the Kara Astrobleme and the Ust`-Kara Area (Pay-Khoy, Kara seashore, Arctic, Russia)

The unusual natural ultrahigh pressure high temperature (UHPHT) impact glasses have been discovered at the Southern part of the Kara astrobleme (Pay-Khoy, Russia) in 2015. The glasses form a complex of stockwork-like system of thin vein bodies set within suevite breccia at the right bank of the Kara river. The Kara glasses have many specific features pointing to UHPHT origin. For better understanding of the geological position of the UHPHT impact glasses we have provided additional field observation with the use of copter facility to observe the outcrops from the «air-bird high» and collecting data for 3D modeling. Here we present natural topological details for the more complete analysis of the discovered UHPHT complex at the Kara River (Pay-Khoy, Russia) and “bottom flow” suevites with UHPHT impact ribbon-like glasses on the Baydarata Bay shore (Kara Sea, Arctic, Russia).

Demanda hospitalaria pediátrica en tiempos de COVID-19

La pandemia del COVID-19 en el Perú está causando una presión inusual a nuestros recursos hospitalarios y de cuidados críticos. A medida que la infección progresa en la población, esperamos ver un alza en los casos severos y en la demanda de unidad de cuidados intensivos (UCI) donde la capacidad de camas puede ser excedida. A pesar de que usualmente el COVID-19 causa una enfermedad poco grave en los niños, debemos estar preparados para que el numero de casos pediátricos ocasionen una sobrecarga en la capacidad de recursos hospitalarios. En un escenario de un 25% de proporción de infección acumulada en la población, podremos ver aproximadamente 891 niños críticamente enfermos que requieren hospitalización en UCI. Proponemos algunas estrategias para enfrentar la escasez de recursos de cuidados intensivos que permitan asegurar la atención de niños vulnerables con condiciones agudas y condiciones complejas que siguen incidiendo en los tiempos de pandemia.

Cyclic and creep combination effects on the long-term undrained behavior of overconsolidated clay

Soft soil subjected to cyclic loading typically exhibits an increase in excess pore pressure under undrained condition which brings the soil to an overconsolidated state. Then, under a subsequent large number of cycles (e.g. more than one million) which also takes time, the creep at overconsolidated state influences the cyclic effect and thus results in a complicated long-term undrained behavior. This paper aims to clarify this long-term undrained behavior of overconsolidated clay. The reconstituted samples are prepared from natural samples retrieved in the north of France. First, the shear strength characteristics along monotonic triaxial stress paths are identified. Then load control cyclic tests on overconsolidated specimens are conducted in fully saturated and undrained conditions. Small cyclic deviatoric stresses are applied in order to investigate more particularly the behavior under a very large number of cycles, during which an unusual pore pressure evolution is observed. To explain this, undrained triaxial creep tests are performed on reconstituted specimens with different values of OCRs under some specified stress states. The evolutions of axial strain, excess pore pressure, stress ratio, stress path, plastic strain rates and stress dilatancy during undrained creep are discussed. The additional undrained creep tests also show that two processes are simultaneously acting in a competitive manner: increase in the pore pressure due to the cyclic loading and decrease in the pore pressure because of creep.

Racial burdens, translations, and chance

Racial burdens, translations, and chance