Saturation Trend Research Articles

Evaluation of on-farm water capture and groundwater decline in the Big Sunflower Watershed, Mississippi River Basin

Study regionBig Sunflower River Watershed (HUC 08030207) of the Lower Mississippi River Basin, United States Mississippi River Valley Alluvial Aquifer Study focusAn on-farm water storage (OFWS) system is a structural best management practice (BMP) that captures irrigation and precipitation runoff from agricultural fields to be reused for irrigation. A geospatial inventory of OFWS systems was conducted in the Big Sunflower River Watershed (BSRW) to quantify surface water used for irrigation. Storage capacity and geographical extent of OFWS systems were compared to aquifer saturation and annual groundwater trends in the underlying Mississippi River Valley Alluvial Aquifer (MRVAA). Changes in surface water storage capacity were measured every two years from 2010 to 2020, and MRVAA trends were evaluated from 2000 to 2020. New hydrological insights for the regionSince 2010, 794.5 ha of surface water storage was added to the BSRW. The lowest aquifer saturation (less than 60%) is in the middle of the watershed, but the area of 60%− 70% saturation is decreasing with the most OFWS systems installed in this area over the entire watershed. MRVAA groundwater levels declined from 2000 to 2015, but drawdowns decreased and water levels rose in observation wells from 2016 to 2020. This paper advances the understanding of how surface water use for irrigation - one of multiple human and natural factors that can affect groundwater levels - impacts MRVAA groundwater resources.

MI-Sensor Element Features and Estimation of Penetration Depth and Magnetic Permeability by Magnetoresistance and Magnetoreactance of CoFeSiB Amorphous Wires

The magnetoimpedance (MI) of amorphous soft magnetic Co <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">68.15</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4.35</sub> Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12.5</sub> B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sub> wires produced by the in-rotating water quenching technique was systematically studied. The behavior of the MI-element designed for magnetic sensors was examined in an external longitudinal dc magnetic field in the low-frequency range (f ≤ 1 MHz) and at the beginning of the intermediate frequency range (2 MHz ≤ f ≤ 5 MHz). A critical frequency of about 5 kHz - 7 kHz was observed with an initial increase in the MI effect. A maximum MI ratio of 334% was recorded at 0.95 MHz in a magnetically saturated MI-element. The intermediate frequency range is explored using the magnetoresistive - MR and magnetoreactive - MX components of magnetoimpedance Z. The MI anisotropy field profile occurs in the MHz operating frequency range with values increasing up to 25 A/m, exhibiting frequency dependence. The magnetic penetration depth was calculated using experimental magnetoresistance data, and the values obtained were about 3 μm - 4 μm for 5 MHz, showing a saturation trend. The magnetic permeability is analyzed in the framework of the electromagnetic classical high-limit model of a cylinder, which includes penetration depth and magnetoreactance. In our experiments and calculations, the classical high limit is satisfied in the operating frequency range of a few MHz. The magnetic permeability peak value is about 35% lower than the comparable data of amorphous CoFeNiMoSiB glass-coated microwires.

The E–I Characteristic Model Based on the Composition Mole Ratio of an Arc on the Ice Surface

The E-I characteristic of an arc propagating over the ice surface is an essential input parameter when applying the ice flashover model. The numerical calculation and prediction of the E-I characteristic are essential to promote the numerical simulation of the discharge on the ice surface. Considering the energy balance of an arc propagates on the ice surface, this paper establishes an E-I characteristic model based on the mole ratio of the arc composition. The particle composition, transport, and E-I characteristics are obtained, and the model’s rationality is verified by comparing it with the existing data. Finally, the influence of the arc’s mole ratio and the arc radius on the E-I characteristics is analyzed. The results show that the E-I characteristics increase linearly with the increase of H2O molar ratio and decrease with the increase of arc radius, which has a saturation trend. The research results can provide a reference for the numerical simulation of an arc propagating over the ice surface.

Safety, efficacy and pharmacokinetics of BPI-9016M in c-MET overexpression or MET exon 14 skipping mutation patients with locally advanced or metastatic non-small-cell lung cancer: a phase Ib study

BackgroundAs a potential target receptor tyrosine kinase, mesenchymal-epithelial transition factor (MET) exhibits high aberrant expression across various tumors. This study aimed to evaluated the safety, tolerability, efficacy and pharmacokinetics (PK) of BPI-9016M, a novel tyrosine kinase inhibitor (TKI) targeting c-MET, in c-MET overexpression or MET exon 14 skipping mutation patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC).Methods/designIn this two-part multicenter phase Ib study, eligible patients with locally advanced or metastatic NSCLC harboring c-MET overexpression or MET exon 14 skipping mutation were enrolled into Part A (tested positive for c-MET overexpression [immunohistochemical staining score ≥ 2+]; 300 mg quaque die [QD], 450 mg QD and 600 mg QD cohorts) or Part B (tested positive for MET exon 14 skipping mutation; 400 mg bis in die [BID] cohort), respectively. The primary endpoints were safety, objective response rate (ORR) and disease control rate (DCR), the second endpoints were PK parameters, progression-free survival (PFS) and overall survival (OS).ResultsBetween March 15, 2017 and September 18, 2021, 38 patients were enrolled (Part A, n = 34; Part B, n = 4). Of 38 patients, 32 (84.2%) patients completed the treatment protocol. As of the data cut-off date on January 27, 2022, all patients reported at least one treatment-emergent adverse event (TEAE). Ninety-two point one percent (35/38) of patients experienced treatment-related adverse events (TRAEs), and grade ≥ 3 TRAEs were observed in 11 (28.9%) patients. The most common TRAEs were elevated alanine aminotransferase (ALT, 14/38, 36.8%) and elevated aspartate aminotransferase (AST, 11/38, 28.9%). Only one (2.6%) patient had treatment-related serious adverse event (SAE) in 600 mg QD cohort due to thrombocytopenia. PK analysis showed BPI-9016M and its main metabolites (M1 and M2-2) reached steady state after seven days of continuous administration. At the dose of 300 mg QD and 450 mg QD, the exposure of BPI-9016M increased with increasing dose. Exposure of BPI-9016M was similar at 450 mg QD and 600 mg QD, which may exhibit a saturation trend. In all patients, ORR and DCR were 2.6% (1/38, 95% confidence interval [CI] 0.1–13.8%) and 42.1% (16/38, 95% CI 26.3–59.2%), respectively. Only one partial response (PR) patient was observed at a dose of 600 mg QD in Part A. In Part B, DCR was 75.0% (3/4, 95% CI 19.4–99.4%). The median PFS and OS in all 38 patients were 1.9 months (95% CI 1.9–3.7) and 10.3 months (95% CI 7.3–not evaluable [NE]), respectively.ConclusionBPI-9016M showed manageable safety profile in c-MET overexpression or MET exon 14 skipping mutation patients with locally advanced or metastatic NSCLC, but showed limited efficacy.Trial registrationClinicaltrials.gov NCT02929290 (11/10/2016).

Effects of pulse rise time on electron dynamics properties in nitrogen–oxygen mixture under repetitive nanosecond pulses

The effects of pulse rise time on the temporal evolution of electron energy and density under repetitive nanosecond pulses in atmospheric nitrogen with 100 ppm oxygen impurities are investigated in this paper by a two-dimensional particle-in-cell/Monte Carlo collision model. It is found that the peak value of mean electron energy increases with decreasing pulse rise time in the single pulsed discharge. However, in the repetitive pulsed discharge approximated by pre-ionization, the peak value of mean electron energy no longer varies with the pulse rise time, showing a saturation trend with decreasing pulse rise time. Whether or not pre-ionization is present, the time required for the mean electron energy to reach its peak is approximately equal to the pulse rise time. It is worth noting that the presence of pre-ionization enhances the tracking ability of the mean electron energy to the pulse waveform during the pulse rise edge. Although after the peak of the pulse, the mean electron energy terminates the tracking process to pulse waveform due to the formation of high-density avalanches and even streamers, its energy decay rate gradually decreases with the increase in the pre-ionization density. Therefore, when the pulse repetitive frequency is greatly increased or the pre-ionization density is increased by other means, it is possible to achieve the complete control of the mean electron energy by pulse waveform modulation.

Interaction of Atomic Deuterium with Rutile TiO2(011)-(2×1)

Inspired by the significance of hydrogen–solid interaction in hydrogen energy and catalysis, adsorption, diffusion, and desorption behaviors of deuterium atoms in rutile TiO2(011) have been investigated by temperature-programmed desorption (TPD) and ultraviolet photoelectron spectroscopy (UPS). Upon exposure, a small portion of D atoms adsorb at surface oxygen sites, resulting in the band gap states at 1.35 eV below the Fermi level and desorbing as water at ∼400 K. Most of the D atoms will diffuse into the bulk due to the relatively low activation barrier and the huge capacity of the solid material. These bulk D species desorb as D2/HD between 500 and 800 K. While the desorbing D2O from surface hydroxyls saturates at ∼0.10 monolayer (ML), the yielding D2 is about 96 ML (equivalent coverage) at the largest atomic D exposure of 4.54 langmuir and no saturation trend has been observed in the present work. Detailed analysis indicates the bulk D will diffuse back to the surface and recombine as D2 at elevated temperatures. The differences between the behavior of H(D) in rutile TiO2(110) and TiO2(011) have been discussed by considering the presence of additional bridging oxygen atoms between the in-plane and topmost ones on the latter surface. The striking finding that most surface D atoms diffuse into the bulk of rutile TiO2(011) will not only broaden our understanding of the interaction of H/D with the prototypical metal oxide material but also provide clues to investigate the mechanism of H/D involving reactions over TiO2 catalysts, for example, hydrogen evolution and hydrogenation.

Effect of Heterogeneity on Capillary Pressure and Relative Permeability Curves in Carbonate Reservoirs. A Case Study for Mishrif Formation in West Qurna/1 Oilfield, Iraq

The special core analysis tests were accomplished on a set of core plugs for Mishrif Formation (mA, mB1, and mB2cde/mC units) in West Qurna/1 oilfield, southern Iraq. Oil relative permeability (Kro) data and the Corey-type fit of the data as functions of the brine saturation at the core outlet face for individual samples in the water-oil imbibition process to estimate relative permeability measurements by the centrifuge method were utilized. Identical correlations for oil and water relative permeabilities were extracted by steady-state and unsteady-state methods. For the mA samples, the gas-water capillary pressure curves were within a narrow range (almost identical) indicating that mA is a homogeneous unit. Kro curves for three mB2ab plugs were practically identical, that is referring to the homogeneity in the upper portion of the unit. The mB2 unit has a more solid‐phase concentration than other units. In addition, the general trend of low residual oil saturation is related to the raising in porosity but no reliable correlation between the residual oil saturation to water drive (Sorw) and Klinkenberg-corrected permeability (Kinf). Based on the correlation between the effective oil permeability at the initial water saturation [ko(Swi)] and (Kinf/f)1/2 for the high-permeability lithofacies mB1 plugs, ko(Swi) is approximately equal to or exceeds Kinf. While ko(Swi) was below Kinf for the other samples. New good empirical equations were obtained for effective gas permeability at final water saturation versus Kinf, as well as, for Kro and Krw versus saturation for all lithofacies.

Routine versus selective near-infrared spectroscopy-guided shunting during carotid eversion endarterectomy.

The aim of this study was to compare outcomes of routine shunting to near-infrared spectroscopy (NIRS)-guided shunting in patients undergoing eversion endarterectomy (EEA) under general anaesthesia. We retrospectively evaluated data of all patients undergoing EEA of the internal carotid artery (ICA) in our department from January 2011 until January 2019. Included were patients with EEA of the ICA and the patients were divided into 2 groups: selective-shunting group and routine-shunting group. Patients (i) with patch angioplasty during the surgery, (ii) undergoing surgery for restenosis and (ii) stenosis after radiation therapy, (iii) without recorded regional cerebral oxygen saturation trends, (iv) presenting with an emergency treatment indication and (v) operated upon by residents were excluded. In all patients, EEA was performed in general anaesthesia and under NIRS monitoring. One-to-one propensity score matching was used to compare EEA outcomes after routine shunting to NIRS-guided shunting. Primary end points were defined as perioperative stroke and in-hospital mortality after EEA. Routine and NIRS-guided selective shunting were applied in 340 (34.0%) and 661 (66.0%) patients, respectively. A total of 277 pairs were generated via propensity score matching. Fifty-eight (20.1%) from the selective-shunting group were intraoperatively shunted. Concomitant procedures were more frequently performed in the routine-shunting group [170 (61.4%) vs 47 (17.0%), 180 (65%) vs 101 (36.5%), and 60 (21.7%) vs 6 (2.2%), P < 0.001]. The perioperative stroke rate in the routine-shunting group was higher as well [11 (4.0%) vs 3 (1.1%), P = 0.022]. In-hospital death was overall 0.2% (n = 1). Multivariable logistic regression in the matched patient indicated age (odds ratio 1.050, 95% confidence interval 1.002-1.104, P = 0.046) and routine shunting (odds ratio 2.788, confidence interval 1.119-7.428, P = 0.032) as risk factors for perioperative stroke during EEA of the ICA. We found that, during EEA of the ICA, under general anaesthesia, NIRS-guided selective shunting was associated with a lower incidence of perioperative stroke than routine shunting.

Multi-hub hydrogen refueling station with on-site and centralized production

In recent decades, the consequences of climate changes due to greenhouse gas (GHG) emissions have become ever more impactful, forcing international authorities to find green solutions for sustainable economic development. In this regard, one of the global targets is the reduction of fossil fuels utilization in the transport sector to encourage the diffusion of more environmentally friendly alternatives. Among them, hydrogen is emerging as a viable candidate since it is a potentially emission-free fuel when produced by exploiting renewable energy sources (RES). Nevertheless, to allow widespread use of this gas in the transport sector, several technoeconomic barriers, including production cost, and lack of distribution and storage infrastructure, have to be overcome. Distributed hydrogen production via renewable energy-powered electrolysis could be an effective solution to reduce cost and lead to economies of scale. In this study a multi-hub configuration with on-site production from PV-powered electrolysis and centralized production from steam methane reforming (SMR) is proposed. In particular, an infrastructure network for a bus refueling station located in Lazio is considered as a case study. First, each hub, composed of PV panels, an electrolyzer, a compression system, high-pressure and low-pressure storages, and hydrogen dispensers with chiller, is modeled in a Matlab/Simulink environment. Then, a design perturbation analysis is carried out to determine the impact of the configuration on the refueling station performance in terms of carbon emissions levels and the Levelized Cost of hydrogen (LCOH). The results show a significant influence of the station size on the economic performance highlighting significant benefits (reduction up to 40% in the LCOH) for a 80 bus HUB with a saturating trend towards larger sizes. CO2 emissions per unit mass of hydrogen are kept limited for all the stations thanks to the synergistic effects of SMR and Electrolyzer. Interconnecting more than one station each other further benefits can be achieved from the environmental perspective (savings up to 5 tons of CO2 are demonstrated for a typical summer case study).

Preparing Silver–Copper pastes in accordance with percolation theory for die attach bonding

The Si die and Cu substrate were successfully bonded with self-developed Ag–Cu pastes through two processes: tube furnace annealing at 250 °C for 30 min in an Ar atmosphere and hot pressing at 250 °C and 5 MPa for 30 min in air. The microstructures, mechanical properties, thermal conductivity, and resistivity of the bonded samples were analyzed and then compared with those of commercial Ag paste. For the samples subjected to tube furnace annealing, the critical Ag volume of the Ag–Cu paste was 35%, shear strength was 5.17 MPa, and resistivity was 9.22 μΩ-cm according to percolation theory. For the samples subjected to hot pressing, the critical Ag volume of the Ag–Cu paste was 75%, shear strength was 8.88 MPa, and resistivity was 12.88 μΩ-cm. The critical Ag volume could not be evaluated on the basis of percolation theory because the thermal conductivity increased gradually with the Ag content, and no saturation trend was observed. The thermal conductivity of the 75 vol% Ag–Cu paste produced through hot pressing was 241 W/mK, which was considerably higher than the commercial Ag paste (thermal conductivity: 48.417 W/mK; electrical resistivity: 400 μΩ-cm), and the cost of 25 vol% Ag particles was successfully reduced.

The enhanced multifunctional behavior in G-type antiferromagnetic BiFeO3 due to the modification by MgTiO3

We have opted for modifying/mixing the conventional BFO multiferroic by Mg-based structure MgTiO3, resulting in the given structural form as (BiFeO3)0.6 (MgTiO3)0.4. The structural distortions from the spin cycloid rhombohedral structure for pure BFO to the orthorhombic arrangement were verified, both from the POWD and Rietveld analysis of the XR-Diffraction database, specifically being transformed to the space group: Pbnm. High εr values, specifically at low-frequency regimes unclog the ceramic's high electric storage ability, which might be as the layered capacitor. Observation of saturated low tangent dielectric loss (tanδ) at higher frequency suggests the compound's applicability for microwave-related applications. It was perceived from the temperature-dependent CIS study that the sharpness of the relaxation mechanism enhances following the contraction in ImZ curves. The fall in the maxima height of the ImZ curves with temperature rise indicates the reduction in the magnitude of (jωC)−1 . The rising peak heights of the M″ curves with rising temperature evince the dominance of long-range thermal conductivities in the solid complex. The optical band gap was found to be tapered relative to the host (BiFeO3), making it a potential candidate for optoelectronics applicability. The Cole-Cole plots suggest the sample's semiconducting feature, together with some non-Debye characteristics induced by electrode-surface irregularities. Weak leakage conduction was observed from the J-E curve, together with a non-linear (non-ohmic) response. The induction of weak ferromagnetism and enhanced saturation trend in the M − H curve suggests partial suppression in the spin cycloid AFM arrangements, brought in by a factor such as bond angle depression between the adjacent ferrite ions.

Investigating the Enhanced Photoresponse in MoS2/GaAs Heterojunction

Herein, the photoresponse properties of a heterojunction of MoS2/GaAs under ambient light conditions are reported. The heterojunctions formed by the chemically deposited MoS2 film on GaAs wafers exhibit an enhancement responsivity by two orders over that of the substrate. The specific detectivity of the system is also found to increase by six orders. The response of the photodetector at varying irradiances demonstrates a trend of saturation of photocurrent. A sensitivity of the order of 3 is obtained for the photoresistor fabricated of the heterojunction. The enhancement of the photoresponse and the responsivity is explained via the absorption of light and the morphology of the MoS2 films.

Heterogeneous Optical Fiber Sensor System for Temperature and Turbidity Assessment in Wide Range.

This paper presents the development of an optical fiber sensor system for multiparametric assessment of temperature and turbidity in liquid samples. The sensors are based on the combination between fiber Bragg gratings (FBGs), intensity variation and surface plasmon resonance (SPR) sensors. In this case, the intensity variation sensors are capable of detecting turbidity with a resolution of about 0.5 NTU in a limited range between 0.02 NTU and 100 NTU. As the turbidity increases, a saturation trend in the sensor is observed. In contrast, the SPR-based sensor is capable of detecting refractive index (RI) variation. However, RI measurements in the turbidity calibrated samples indicate a significant variation on the RI only when the turbidity is higher than 100 NTU. Thus, the SPR-based sensor is used as a complementary approach for the dynamic range increase of the turbidity assessment, where a linearity and sensitivity of 98.6% and 313.5 nm/RIU, respectively, are obtained. Finally, the FBG sensor is used in the temperature assessment, an assessment which is not only used for water quality assessment, but also in temperature cross-sensitivity mitigation of the SPR sensor. Furthermore, this approach also leads to the possibility of indirect assessment of turbidity through the differences in the heat transfer rates due to the turbidity increase.

Annealing Effect on the Structural, Magnetic, Electrical, Optic Property, Nanomechanical, and Adhesive Characteristics of Co60Fe20Yb20 Thin Films on Glass Substrate

In this study, X-ray diffraction (XRD) analysis showed the amorphous nature of the Co60Fe20Yb20 films deposited at room temperature (RT), 100 °C, and 200 °C. The body-centered cubic (BCC) CoFe (110) characteristic peak was visible at 44.7° after annealing films of 40 nm and 50 nm at 300 °C. The highest alternating current magnetic susceptibility (χac) value was 0.21 at 50 Hz in a 50 nm, and the lowest resistivity value was 1.02 (×10−2 Ω·cm) in a 50 nm. In terms of nano-indication measurement, the highest value of hardness was 9.29 GPa at 300 °C in a 50 nm. When the thickness increased from 10 nm to 50 nm, the hardness and Young’s modulus of the Co60Fe20Yb20 film also showed a saturation trend. The Co60Fe20Yb20 film had the maximum surface energy at 50 nm after 300 °C annealing. The transmittance of Co60Fe20Yb20 films decreased when the thickness was increased because the thickness effect suppresses the photon signal. Due to high χac, low electrical performance, strong nano-mechanical properties, and high adhesion, it was discovered in this work that 50 nm with annealing at 300 °C was the ideal condition for the magnetic and adhesive capabilities of Co60Fe20Yb20 film. More importantly, replacing the CoFeB seed or buffer layer with a thin CoFeYb film improved the thermal stability, making CoFeYb films attractive for practical magnetic tunnel junction (MTJ) applications. Furthermore, the specific properties of Co60Fe20Yb20 films were compared to those of Co60Fe20Y20 films, demonstrating that the specific properties of these two materials may be compared.

Spatial Variation in Catchment Response to Climate Change Depends on Lateral Moisture Transport and Nutrient Dynamics

AbstractFuture shifts in rainfall, temperature and carbon dioxide (CO2) will impact hydrologic and ecosystem behavior. These changes are expected to vary in space because water and nutrient availability vary with terrain and soil properties, with feedbacks on vegetation and canopy adjustment. However, within‐basin patterns and spatial dependencies of ecohydrologic dynamics have often been ignored in future scenario modeling. We used a distributed process‐based ecohydrologic model, the Regional Hydro‐Ecological Simulation System, as a virtual catchment to examine spatial and temporal variability in climate change response. We found spatial heterogeneity in Leaf Area Index, transpiration and soil saturation trends, with some scenarios even showing opposite trends in different locations. For example, in a drying scenario, decreased vegetation productivity in water‐limited upslope areas enhanced downslope nutrient subsidies so that productivity increased in the nutrient‐limited riparian zone. In scenarios with both warming and rising CO2, amplifying feedbacks between mineralization, vegetation water use efficiency and litter fall led to large increases in growth that were often strongest in the riparian area (depending on the coincident rainfall change). Modeled transpiration trends were determined by the competing effects of vegetation growth and changing water use efficiency. Overall, the riparian zone experienced substantially different (and even opposing) ecohydrologic trends compared to the rest of the catchment, which is important because productive riparian areas often contribute a disproportionate amount of vegetation growth, transpiration and nutrient consumption to catchment totals. Models that are spatially lumped, lack key ecosystem‐driving dynamics, or ignore lateral transport could misrepresent the complex ecohydrologic changes catchments could experience in the future.

Investigations on Mode Transition Mechanisms and Discharge Characteristics of Electrically Exploding Aluminum Wires in Argon Gas

Electrically exploding wires (EEWs) are a promising method for nanoparticle preparation, and the size distribution of nanoparticles is significantly affected by ambient pressure. However, the influence of ambient pressure on EEW characteristics is still unclear, which brings incredible difficulties in parameter optimization for nanoparticle preparation. In this article, mode transition mechanisms and discharge characteristics of EEWs in argon gas were experimentally investigated. A mode transition of EEWs, from the shunting to the internal as ambient pressure increases, was demonstrated through electrical measurement. The ohmic heating duration, maximum power, and breakdown electric field increase with ambient pressure in shunting mode and show a saturated trend in internal mode. Through laser imaging and framing imaging, two typical structures of EEWs, that is, the “core-corona” structure ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$p &lt; 50$ </tex-math></inline-formula> kPa) and the “discharge channel-vapor” structure ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$p &gt;200$ </tex-math></inline-formula> kPa), were observed and analyzed. By reconstructing evolutionary trajectories of coronal plasmas and high-density cores, we have found that increased ambient pressure inhibits the diffusion processes of EEWs. According to ambient pressure, EEW in argon gas was divided into four regions: shunting, transitional, internal, and saturated.

Prevention of Shivering Post Subarachnoid Block: Comparison between Different Doses of Intravenous Magnesium Sulphate.

Background and Objectives: Shivering is a common complication of subarachnoid block (SAB). Magnesium sulphate has been proven to be effective in preventing shivering. The aim of this study was to compare the effectiveness and adverse effects in hemodynamic parameters between 50 mg/kg and 30 mg/kg of intravenous magnesium sulphate for prevention of shivering post-subarachnoid block. Materials and Methods: Eighty-six patients scheduled for surgery under SAB, aged between 18 to 65 years old with American Society of Anesthesiologists physical status I and II were randomised into two groups. Group A received a bolus of 50 mg/kg, while Group B received 30 mg/kg of intravenous magnesium sulphate, given over a 20 min duration following SAB. Shivering grade was recorded intraoperatively according to the Crossley and Mahajan shivering scale. Mean arterial pressure (MAP), heart rate, tympanic temperature, oxygen saturation and the use of vasopressors were recorded. Results: Forty-five percent of patients in Group A and 20% of patients in Group B did not exhibit shivering (p-value < 0.01). High-grade shivering was observed in 12.5% in Group A and 40% in Group B, respectively (p-value 0.02). The MAP trend was lower in Group B (p-value < 0.01), but the incidence of hypotension was not significant in both groups. The use of vasopressors was also similar between groups. Group B showed a lower oxygen saturation trend (p-value 0.04). The trends of heart rate and tympanic temperature were not significant in both groups. No patients had episodes of bradycardia or oxygen desaturation. Conclusions: In this study, intravenous magnesium sulphate 50 mg/kg is the lowest effective dose for prevention and treatment of high-grade shivering post-SAB without significant hemodynamic adverse events.

Geological Reservoir Characterization of a Gas Hydrate Prospect Associated with the Hydrate-01 Stratigraphic Test Well, Alaska North Slope

Geological reservoir characterization is essential for accurate evaluation of gas production performance from gas hydrate reservoirs. Particularly, the understanding of reservoir architecture and heterogeneity is of great importance since these are considered as major controls on fluid hydrodynamic and thermodynamic conditions. This study deals with well log and three-dimensional (3-D) vertical seismic profile (VSP) data acquired from the Hydrate-01 Stratigraphic Test Well within the 7-11-12 prospect, Prudhoe Bay Unit, Alaska North Slope and reports on the results of geological/geophysical evaluation related to the geological structure and reservoir properties of the 7-11-12 prospect. The structural trends of the target reservoirs, based on well correlations, are mostly consistent with the predrill prediction using the surface seismic data, and infer the existence of subseismic faults cutting through the Hydrate-01 well. The 3-D VSP data confirm a down-to-the-east normal fault that offsets the reservoir units across the Hydrate-01 well, which is concordant with the well identification of the same fault, and indicate a northeast-dipping relay structure associated with the overstepping normal faults. The edge enhancement attribute associated with discontinuity generated from the 3-D VSP data shows small faults/fractures, possibly as part of a complex fault network within the imaged normal fault system. These results reveal that the 3-D VSP data provide detailed structural information that is not present from the surface seismic data. The Hydrate-01 well log data confirm the occurrence of gas hydrate at high saturation in the two targeted sand units (B1 and D1 sands), and the comparison to a nearby pre-existing well (7-11-12 well) shows the same general trend in gas hydrate saturation as a map of seismic impedance generated from surface seismic data. The well log data also suggest that the base of gas hydrate occurrence in the Hydrate-01 and 7-11-12 wells is almost aligned at the same depth in both of the targeted B1 and D1 sand reservoirs. Especially for the D1 sand in the Hydrate-01 well, the resistivity logs show a sharp transition from high gas hydrate saturation to fully water-saturated within the D1 sand, suggesting a common gas hydrate/water contact. The results of this study will be used to construct the geological models needed for reservoir simulation studies and they can provide important insights into the geological factors that control the occurrence of gas hydrate on the Alaska North Slope.

Effects of Annealing and Thickness of Co60Fe20Yb20 Nanofilms on Their Structure, Magnetic Properties, Electrical Efficiency, and Nanomechanical Characteristics

X-ray diffraction (XRD) analysis showed that metal oxide peaks appear at 2θ = 47.7°, 54.5°, and 56.3°, corresponding to Yb2O3 (440), Co2O3 (422), and Co2O3 (511). It was found that oxide formation plays an important role in magnetic, electrical, and surface energy. For magnetic and electrical measurements, the highest alternating current magnetic susceptibility (χac) and the lowest resistivity (×10−2 Ω·cm) were 0.213 and 0.42, respectively, and at 50 nm, it annealed at 300 °C due to weak oxide formation. For mechanical measurement, the highest value of hardness was 15.93 GPa at 200 °C in a 50 nm thick film. When the thickness increased from 10 to 50 nm, the hardness and Young’s modulus of the Co60Fe20Yb20 film also showed a saturation trend. After annealing at 300 °C, Co60Fe20Yb20 films of 40 nm thickness showed the highest surface energy. Higher surface energy indicated stronger adhesion, allowing for the formation of multilayer thin films. The optimal condition was found to be 50 nm with annealing at 300 °C due to high χac, strong adhesion, high nano-mechanical properties, and low resistivity.

Generalized additive models to analyze nonlinear trends in biomedical longitudinal data using R: Beyond repeated measures ANOVA and linear mixed models.

In biomedical research, the outcome of longitudinal studies has been traditionally analyzed using the repeated measures analysis of variance (rm-ANOVA) or more recently, linear mixed models (LMEMs). Although LMEMs are less restrictive than rm-ANOVA as they can work with unbalanced data and non-constant correlation between observations, both methodologies assume a linear trend in the measured response. It is common in biomedical research that the true trend response is nonlinear and in these cases the linearity assumption of rm-ANOVA and LMEMs can lead to biased estimates and unreliable inference. In contrast, GAMs relax the linearity assumption of rm-ANOVA and LMEMs and allow the data to determine the fit of the model while also permitting incomplete observations and different correlation structures. Therefore, GAMs present an excellent choice to analyze longitudinal data with non-linear trends in the context of biomedical research. This paper summarizes the limitations of rm-ANOVA and LMEMs and uses simulated data to visually show how both methods produce biased estimates when used on data with non-linear trends. We present the basic theory of GAMs and using reported trends of oxygen saturation in tumors, we simulate example longitudinal data (2 treatment groups, 10 subjects per group, 5 repeated measures for each group) to demonstrate their implementation in R. We also show that GAMs are able to produce estimates with non-linear trends even when incomplete observations exist (with 40% of the simulated observations missing). To make this work reproducible, the code and data used in this paper are available at: https://github.com/aimundo/GAMs-biomedical-research.