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Objective: For degenerative diseases accompanied by cervical malalignment, the starting and ending points of fixation for better cervical sagittal alignment and clinical results are not as clear as the thoracolumbar region. In this study we aimed to compare the effects of posterior subaxial cervical fixation (PSCF), posterior cervical fixation extending to the upper thoracic region and posterior upper cervical fixation extending to the upper thoracic region on cervical sagittal alignment. Methods: Sixty‐three patients who underwent posterior cervical and cervical‐up thoracic fixation were retrospectively analyzed in a comparative study. The procedures that we performed from May 2019 to March 2022 on these 63 patients were: (1) C3‐C6 group—posterior subaxial cervical fixation; (2) Subaxial‐T2 group—posterior subaxial cervicothoracic fixation (PSCTF); (3) C2‐T2 upper thoracic posterior fixation group. The C3‐C6 group had 27 patients, Subaxial‐T2 group had 24, and C2‐T2 group had 12. We determined the minimum follow‐up period as 12 months. C0‐2, C2‐7 lordosis angle, sagittal vertical axis (SVA), C2 slope, C7 slope, T1 slope, cervical slope, neck slope, and thoracic inlet angle (TIA) measurements were made in three patient groups. Comparatively, cervical sagittal alignment was evaluated. Result: In the C2‐T2 group, a significant increase in C2‐C7 lordosis, decrease in C2 slope, and increase in TS‐CL were observed. Significant C2‐C7 lordosis decrease, C2 slope increase, and TS‐CL decrease were observed in the C3‐C6 group. A significant increase in C2‐C7 lordosis and a decrease in C2 slope were observed in the subaxial‐T2 group. No significant change was observed in the TS‐CL angle. Conclusion: In cervical degenerative disorders accompanied by cervical malalignment, we recommend the C2‐T2 fixation method, which provides the desired C2‐C7 lordosis, SVA within the normal range, and the best Neck Disability Index results. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Short‐circuiting in secondary clarifiers is a well‐known problem that can occur through up‐flow or underflow routes. The underflow short‐circuiting is not as visible as up‐flow short‐circuiting but can affect clarifier performance. The energy‐dissipating inlet (EDI) is a type of inlet structure that is used in secondary clarifiers to dissipate the energy of larger influent volumes, allowing clarifiers to operate at higher treatment capacities. The underflow short‐circuiting is encountered particularly in clarifiers equipped with EDIs. As influent volume increases, conventional draw‐off pipes cannot handle high sludge capacities, deforming the sludge blanket and leading to lower concentration of solids being withdrawn. Retrofitting the design of draw‐off pipes is an effective way to mitigate underflow short‐circuiting and enhance treatment performance. In this study, a snail‐shaped sludge draw‐off pipe was designed and tested in two types of EDIs using computational fluid dynamics tools, showing a 20% increase in withdrawn sludge concentration and mitigating underflow short‐circuiting potential. The optimal retrofit option was identified as equipping the clarifier with a snail‐shaped draw‐off pipe and an innovative EDI, known as multilayer EDI column, which would save almost half of the energy and operational costs of the biological processes while meeting discharge limits. [ABSTRACT FROM AUTHOR]

Limited experimental research has been conducted on organic Rankine cycle (ORC) systems that use wet working fluids. Therefore, the present study examined how the performance of an ORC system that uses a wet working fluid (R134a) was affected by the superheat degree ratio (SDR) under various scroll rotation speeds. The SDR is the dimensionless ratio between superheat degree and evaporation temperature at a given heat source temperature. Experimental results indicated that at scroll rotation speeds of 900, 1350, and 1800 rpm, the maximum output power of the aforementioned system was 1103, 1464, and 1537 W, respectively, with SDRs of 0.49, 0.49, and 0.54, respectively. The maximum net efficiencies at these speeds were 5.87%, 5.91%, and 5.32%, respectively, which occurred at SDRs of 0.61, 0.49, and 0.48, respectively. This level of system performance was attributable to the high enthalpy at the expander inlet and the high mass flow rate at the high evaporation pressure under an SDR of approximately 0.5. Although increasing the SDR did not enhance the scroll expander's isentropic efficiency, this efficiency decreased considerably when the SDR fell below 0.2. These findings emphasize the importance of optimizing the SDR of ORC systems to improve their performance. [ABSTRACT FROM AUTHOR]

In this paper, a novel air‐cooled supercapacitor thermal management system (STMS) based on the corner deflectors and the inclined inlet and outlet was proposed. The temperature and velocity fields were simulated and analyzed by CFD. Moreover, the heat dissipation effect of different STMSs was analyzed against each other. The results showed that the STMS proposed had a better heat dissipation effect when the inclined angle of inlet and outlet was appropriate, in which the maximum temperature (Tmax) and the maximum temperature difference (ΔTmax) of the module could be reduced by 10.3% and 34.6%. And it is shown that the structure with inclined inlet and outlet plays an important role for the heat dissipation capability of the STMS proposed. And it has experimentally proven its heat dissipation ability. Consequently, the impacts of inclined angle (α), monomer spacing (dc), and the distance between monomer and module shell (dx, dy, and dz) on the heat dissipation effect were deeply analyzed. For the STMS arranged in four rows and three columns, it had a better heat dissipation effect when inclined angle was in the range of 40° to 50°. The results showed that the structural parameters had a large influence on the Tmax and ΔTmax. Besides, it had shown that the temperature curves of the Tmax and ΔTmax had a main trend of "decreasing and then increasing" when the monomer spacing as well as the distance between monomer and module shell are taken from 1 mm to 5 mm. It implies that a small spacing (1 mm to 2 mm) will hinder the air circulation and reduce heat dissipation, and a large spacing (3 mm to 5 mm) will reduce the average flow rate of air and reduce the efficiency of heat transfer. [ABSTRACT FROM AUTHOR]

The northern inlet channel to Jezero crater (Sava Vallis) terminates in a fan‐shaped depositional feature, part of which blends into the separate well‐known western fan delta that is the field site for the Mars 2020 mission's Perseverance rover. Jezero's northern fan potentially represents either a second fan delta within the crater or a distal portion of the western fan. To constrain the fluvial and sedimentological history of Jezero and place the rover's in situ observations in proper geologic context, we photogeologically map the northern fan deposits at a larger mapping scale than previous studies, using ground‐based imaging from the Perseverance rover for context. Fifteen map units are identified using HiRISE‐based interpretations of geologic characteristics and inferred processes as well as crosscutting relative age relationships. Mapped units are also defined based on orbital data from CRISM and THEMIS to assess their compositional signatures. We interpret the northern fan deposits as older than the uppermost blocky unit in the western fan delta, suggesting that they were deposited contemporaneously with or prior to the deposition of the western fan, and under similar climate conditions. The eastern portion of the northern fan deposits shows evidence of fluvial deposition from Sava Vallis, while part of its western side could represent a distal part of the western fan delta. We synthesize our interpretations to present scenarios for the deposition of the northern and western fans, which can help constrain the history of both watersheds and place it into context within the broader Isidis basin region. Plain Language Summary: The Mars 2020 Perseverance rover has primarily focused on using its scientific instruments to study the delta along Jezero crater's western margin. But there are fan‐shaped features that appear to originate from both the crater's western and northern channels ‐ Neretva Vallis and Sava Vallis, respectively. In this project, we compile orbital images, spectroscopy data sets, and images taken by the rover's Mastcam‐Z instrument to investigate whether the northern fan originated from the northern channel or is an outlying part of the western delta. Based on these observations and the geologic map created using them, we show that the northern fan deposits are older than the uppermost unit mapped in the western delta. We also demonstrate how the western portion of the northern fan deposits could be an outer part of the western delta, while the eastern portion may preserve material from Sava Vallis. We show that some units across the northern and western fans are the same or similar, making this work useful as the rover's mission continues. Finally, we present scenarios that could lead to what we see in Jezero today, helping us to understand the potential history of this area and the relationship between the northern and western watersheds. Key Points: Deposition of Jezero crater's northern fan predates that of its western fan blocky material—the western delta's uppermost surficial unitThe northern fan shows evidence of deposition from Sava Vallis, but part of its western region could be a distal part of the western deltaThe stratigraphic and depositional hypotheses presented provide context for the Mars 2020 mission and help constrain the history of both watersheds [ABSTRACT FROM AUTHOR]

The double‐layer porous media burner is considered as an effective way to realize stable lean‐burn. In order to quickly achieve a stable combustion state in a double‐layer porous media burner, this work investigated the dynamic characteristics of methane/air premixed combustion in a bench‐scale double‐layer porous media burnspanning from ignition to stable combustion and ultimately flameout. The experimental results indicate that regulating the equivalence ratio and the inlet velocity enables the establishment of a stable flame front and the φ = 0.75 and the Vin = 0.20 m/s are the appropriate start‐up conditions. The average propagation velocity of the combustion wave variation along the axial direction and ranged approximately from −0.022 to −0.078 mm/s. Moreover, the transition time to a stable combustion state is reduced by nearly 47.14% as the equivalence ratio increases from 0.60 to 0.70. During start‐up stage, there are significant fluctuations in CO and NOx concentrations, but both emissions remain low during steady combustion state, with the maximum concentrations of 37.5 and 40.2 mg/m3, respectively. Furthermore, the porous media combustion exhibits a pronounced re‐ignition capacity. At higher equivalence ratios, longer interruptions of premixed gas are allowed. [ABSTRACT FROM AUTHOR]

The process of smelting non‐ferrous metals results in significant emissions of flue gas that contains sulfur dioxide (SO 2$$ {}_2 $$), which is very harmful to the environment. Through precise control of converter inlet temperature, it is feasible to enhance the conversion ratio of SO 2$$ {}_2 $$ and simultaneously mitigate environmental pollution by generating acid from flue gas. Because of the high degree of uncertainty in smelting process, converter inlet temperature is challenging to regulate and controller frequently needs updating. To improve control performance and decrease controller update times, an event‐triggered neural network model predictive control (ETNMPC) strategy is proposed. First, long short‐term memory (LSTM) prediction model and model predictive controller are developed. Second, it is decided whether to update the existing controller by designing an event‐triggered mechanism. Finally, using real data from a copper facility in Jiangxi Province, the temperature control experiment of converter inlet is carried out. Simulation results demonstrate that the proposed ETNMPC outperforms conventional time‐triggered method in terms of control performance, greatly lowers the times of controller updates, and significantly lowers computation costs and communication burden. [ABSTRACT FROM AUTHOR]

This groundbreaking study introduces a scientifically robust method for assessing internal heat generation in shallow, unsaturated aquifers, highlighting the intricate interplay between internal heat, thermal diffusivity, and hydraulic flux. The research pioneers a novel approach employing time‐frequency spectral analysis to address challenges posed by conventional methods that rely solely on prescribed thermal diffusivity and hydraulic flux for evaluating internal heat over time. Rooted in a solid theoretical framework supported by meticulous temperature and heat flux observations, the method adeptly incorporates the concept of an unknown internal heat. The study systematically explores three distinct boundary conditions, showcasing versatility: one with fixed temperatures at the inlet and outlet, another with known temperature at the inlet and no heat flux at the outlet, and a third with a prescribed inlet temperature and constrained outlet heat flux. The estimation of internal heat, coupled with prescribed thermal diffusivity and hydraulic flux, harnesses in‐situ temperature and heat flux spectra through an innovative inverse stochastic spectral approach. A notable feature of this research lies in its ability to strategically handle various parameters, including prescribed thermal diffusivity, hydraulic flux, variations in target depth, significant frequency components, and boundary conditions. The variation assessment findings emphasize the diverse range when predicting internal heat generation based on prescribed thermal diffusivity and hydraulic flux. This study facilitates the determination of potential internal heat magnitudes at different depths and provides profound insights into in‐situ conditions within the vadose zone. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: The smelting of non‐ferrous metals produces substantial quantities of sulfur dioxide (SO2$$ {}_2 $$)‐laden flue gas, which is seriously harmful to environment and humans. To improve the conversion ratio of SO2$$ {}_2 $$ and minimize environmental pollution, controlling converter inlet temperature during acid production has proven to be an efficient approach. However, unsteadiness of smelting procedure leads to frequent changes in the concentration of SO2$$ {}_2 $$, which affects the catalytic conversion of SO2$$ {}_2 $$ and the production of sulfuric acid. To regulate converter inlet temperature, a proposed method of multi‐model predictive control is introduced. First, working conditions are divided and characterized according to the range of SO2$$ {}_2 $$ concentration. Then, the mathematical model is established for each working condition and the model predictive controller is designed. Finally, an effective switching mechanism is established to realize smooth switching under different working conditions and closed‐loop control of the whole system. Through simulation validation, compared with traditional single‐model predictive controllers and multi‐model PID controllers, the proposed approach demonstrates improved transient performance and steady‐state performance. Simulation outcomes clearly highlight the superiority of the proposed algorithm. [ABSTRACT FROM AUTHOR]

To solve the high heat dissipation problem of lithium ion battery, the air‐cooled heat dissipation with fins is adopted for the thermal management. Heat dissipation characteristics of two types of air inlets and outlets (single air inlet and outlet, and double air inlet and outlet) and two types of surfaces (smooth and fin structure) were simulated and compared. When the air inlet and outlet are single inlet and single outlet, compared with smooth battery packs, finned construction packs can increase the Nusselt number by 24.9%. When the air inlet and outlet are double inlet and double outlet, compared with smooth battery packs, finned construction packs can increase the Nusselt number by 13.3%. The double‐air inlet and outlet battery pack can significantly reduce the average temperature of the battery pack compared with the single‐air inlet and outlet battery pack. Compared with the single‐inlet and single‐outlet solar smooth battery pack, it can increase the Nu by 131.6%, and the comprehensive performance index can reach 1.66. [ABSTRACT FROM AUTHOR]

Introduction: Gastric inlet patches are often incidental, but can also be a treatable cause of laryngo‐esophageal symptoms. Methods: We retrospectively reviewed all patients whose gastric inlet patches were diagnosed following assessment for laryngopharyngeal and swallowing symptoms. Improvement following Argon Plasma Coagulation (APC) was assessed using Minimum Clinically‐Important Difference methodology combining voice, throat, and swallowing domains. Correlations between APC response and measures of reflux and mucosal barrier integrity, measured during 24‐h pH‐impedance manometry, were obtained. Proximal and Distal Mean Nocturnal Baseline Impedance (MNBI) values were separately calculated and the novel variable of Mucosal Impedance Gradient was derived as [((Distal MNBI‐Proximal MNBI)/((Distal MNBI + Proximal MMBI)/2)) x 100]. Key Results: Inlet patches were detected in 57 of 651 patients who had Transnasal Panendoscopy (8.7 ± 2.2%). There were 34 males. Mean age was 58 years. Mean duration of symptoms was 2 years. The commonest symptoms were hoarseness (n = 33), throat symptoms (n = 24), and dysphagia (n = 21), respectively. APC was used to ablate patches in 34 patients. Treatment response was 71% at a mean followup of 5.5 months. MIG > − 25% predicted response to APC, with area under the receiver operating characteristic curve of 0.875 (Sensitivity = 81%; Specificity = 100%; p < 0.0001). Conclusions: Gastric inlet patches are common and under‐recognized. They can cause protracted pharyngo‐esophageal symptoms. Patch ablation is an effective treatment for carefully selected patients. Optimal patient selection requires multidisciplinary teamwork. Mucosal Impedance Gradient could further refine patient selection. [ABSTRACT FROM AUTHOR]

Objective: Hatcheries are used to help supplement populations of Pacific salmon Oncorhynchus spp. for conservation and fisheries purposes and to provide stewardship opportunities. In British Columbia, small community-run hatcheries typically focus on the latter and generally do not know the efficacy of their release approaches, unlike larger production hatcheries. Methods: We used acoustic telemetry to track the survival and behavior of 90 hatchery-reared Coho Salmon O. kisutch smolts, released from a community hatchery, through Burrard Inlet and into the Strait of Georgia. This is the first study to track Coho Salmon smolts released directly into a marine environment and one of very few studies to track them in an oceanic setting. Result: Smolt survival was lowest through the first 3 km of the migration at 37%, and the estimated cumulative survival to the final array (~20 km from release) was 10-23%. The presence of numerous predators in the region suggests that predation is a possible explanation for poor survival over the relatively short migration distance. Travel rates ranged from ~4 to 18 km/day, depending on the migration segment, which is slower than the marine migration of smolts from other species, likely increasing exposure to predators. However, we found potential evidence of "predator swamping," as survival estimates across migration segments were highest for the final of our three release groups and poorest for the first release group, with intergroup survival estimates increasing by 7-12% in the final three migration segments. Releasing smolts at high densities and at night, as our partner hatchery currently does, likely improves smolt survival. Conclusion: Our work demonstrates how acoustic telemetry can be used to examine hatchery practices and propose potential improvements. Saltwater readiness and the release location are factors that our results suggest may warrant future attention to potentially improve marine survival of Coho Salmon smolts. [ABSTRACT FROM AUTHOR]

Although there are many studies evaluating optimal inlet and outlet angles required for the correct placement of S1 iliosacral screws, there is no study evaluating reliability and feasibility of these angles for all individuals on three‐dimensional (3D) anatomical models. A total of 100 women and 100 men were selected randomly. A vertical line was created according to long axis of the tomography device on which patient was lying in supine position. The automatized best‐fit planes were created on superior and inferior endplates, anterior cortex including notch region and posterior cortex of first sacral vertebrae using 3D imaging software to measure mean inlet and outlet angles. We observed no statistically significant difference between gender groups in terms of inlet and outlet angles. Mean inlet view is obtained for anterior cortex of S1 in 22.5 ± 9.5° and for posterior cortex in 46.5 ± 9.3°. Mean fluoroscopic view angle of S1 for superior outlet is 40.3 ± 7.6 and for inferior outlet is 46.9 ± 8.8. Mean anterior and posterior S1 inlet view angles do not accurately visualize anterior cortex of 74 (37%) and posterior cortex of 66 (33%) individuals. Mean superior and inferior S1 outlet view angles do not accurately visualize superior endplate of 74 (37%) and inferior endplate of 56 (28%) individuals. Due to individual alterations of spatial position of sacrum, mean inlet and outlet view angles of S1 are not sufficient to visualize the iliosacral screws under fluoroscopy in many individuals. [ABSTRACT FROM AUTHOR]

Gas turbine combustors are often subjected to combustion instabilities because of variability of operating conditions, affecting components, and altering exhaust emissions. Herein, the analysis focuses on simulating numerically the non‐premixed combustion as unsteady flamelet combustion and detailed kinetic mechanism. The goal is analyzing exhaust gases under unsteady inlet airflow conditions to define operation guidelines. The numerical approach is validated using data from the literature for nonperturbed cases. Three periodical perturbations of different amplitude show differences with the nonperturbed case. Besides emission of exhaust gases, the temperature field is sensitive to airflow inlet conditions. According to the simulation results, a strong dependence of temperature and pressure in primary and dilution zones of combustor exists on the inlet air pressure condition. Emissions of flue gases like CO and NOx respond to combustor thermal behavior showing high sensitivity to inlet air pressure as well. Results indicate that moderate pressure oscillations may derive into flashback effects. [ABSTRACT FROM AUTHOR]

The impact of a large shallow semi‐enclosed lagoon on freshwater exchange across an inlet channel is investigated using an idealized numerical model. Lagoons are often found between a river mouth and the ocean; we focus on those where the river discharge rate is small and the inlet channel is narrower and deeper than the lagoon. Tides generate freshwater and oceanic‐water plumes across the channel; a stratified freshwater plume forms in the ocean from the late ebb to early flood phase, while a vertically well‐mixed oceanic‐water plume forms in the lagoon from the late flood to early ebb phase. The shallow depth of the lagoon increases the flow speed of the oceanic‐water plume, which results in the formation of a sharp and vertically well‐mixed salinity front within the lagoon. When this front moves toward the ocean during the ebb phase, vertical mixing increases where the bathymetry deepens and freshwater encounters oceanic water below. Without a dredged bottom slope, the impact of mixing would be greatly reduced within the shallow lagoon and channel, as the shallow depth would limit the subsurface intrusion of oceanic water. The narrow channel further causes the flow to converge and accelerate, enhancing both internal shear‐driven and bottom boundary‐layer mixing at the channel and increasing freshwater plume thickness where it enters the ocean. Sensitivity experiments showed that the role of tidal pumping in freshwater exchange across the channel increases when the lagoon area and tidal mixing increase and when the estuarine Richardson number decreases. Plain Language Summary: Freshwater outflows from estuaries play an important role in supporting coastal marine environments. Large shallow lagoons are often found at river mouths with an inlet channel; this study uses idealized numerical model experiments to investigate how lagoons affect freshwater exchange across an inlet channel where the river discharge rate is low. Freshwater exchange often results in estuarine circulation wherein freshwater enters the ocean near the surface, while oceanic water intrudes into the estuary near the bottom, with weaker circulation expected for a shallow environment. We find that large lagoons force strong tidal flows across the channel, enhancing mixing between freshwater and oceanic water, especially during the ebb phase. Due to the fast flow generated over the shallow lagoon, mixing occurs when freshwater in the lagoon moves across a sloping bottom and interacts with oceanic water below. Freshwater outflow becomes thicker and tidally pulsed plumes are generated. Key Points: A large lagoon with a narrow inlet induces strong tidal pumping across the channel, in turn generating plumes in the ocean and lagoonMixing is enhanced as the sharp salinity front formed within the shallow lagoon moves across the sloping bottom during the ebb phaseTidal pumping induces more freshwater exchange than estuarine circulation when the estuarine Richardson number is below unity [ABSTRACT FROM AUTHOR]

In this article, we substantiate the appositeness of the mode‐matching technique to study the scattering response of bridging elastic plates connecting two flexible duct regions of different heights. We present two different solution schemes to analyze the structure‐borne and fluid‐borne radiations in the elastic plate‐bounded waveguide. The first scheme supplements the mode‐matching technique with the so‐called tailored‐Galerkin approach that uses a solution ansatz with homogeneous and integral parts corresponding to the vibrations of the bridging elastic plate and the cavity, respectively. In the second scheme, we supplement the mode‐matching technique with the modal approach wherein the displacement of the bridging elastic plate is projected onto the eigenmodes of the cavity. To handle the non‐orthogonality of the eigenfunctions, we invoke generalized orthogonality relations. An advantage of the proposed mode‐matching schemes is that they provide a convenient way of incorporating a variety of edge conditions on the joints of the plates, including clamped, pin‐joint, or restraint connections. The numerical analysis of the waveguide scattering problems substantiates that edge connections on the joints have a significant impact on the scattering energies and transmission loss. Furthermore, it appears that the transmission loss and structural vibration attenuation in the expansion chamber may be improved by adjusting chamber dimensions and excitation modes. [ABSTRACT FROM AUTHOR]

Powder mixers are used in many industries. In the present work, a new type of air swirling mixer was designed and optimized with eight horizontally arranged inlet pipes at the tangential inlet angle of 35°. The mixing of multi‐sized spherical particles (2.0, 3.0, 4.0, and 5.0 mm) was numerically investigated in the air swirling mixer by coupled computational fluid dynamics–discrete element method. The numerical results showed that multi‐sized particles achieved comparable mixing performance to monodisperse particles. The Lacey index for multi‐sized particles increased initially, and then reached a maximum value at 0.824. The upward velocity of the particles, vz, increased initially, and then decreased to zero along the bed height. The maximum value of vz occurred at a height of 40 mm. Particle radial velocity was larger near the wall than at the mixer tube centre area. The smallest particles aggregated in three layers. The collision number of the particles reached a maximum at bed height of 120 mm, which was consistent with the position of the maximum stress of the particles against the tube wall. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the well‐posedness of impinging flow through a semi‐infinitely long nozzle and impacting on a plane. More precisely, given the semi‐infinitely long nozzle with finite inlet, the plane, and the positive incoming horizontal velocity, then there exists a unique smooth solution to the impinging flow. Moreover, there exists a smooth free interface that separates the fluid such that it flows out of different outlets in the downstream. [ABSTRACT FROM AUTHOR]

The expected increase in rates of sea level rise during the 21st century and beyond may cause barrier islands to drown. Barrier drowning occurs due to a sediment imbalance induced by sea level rise, causing inlets to open and expand. It is still unclear how fast barrier islands can drown. To gain insight into the morphodynamics of barrier systems subject to sea level rise, we here present results obtained with a novel barrier island exploratory model, BarrieR Inlet Environment‐Drowning, that considers inlet expansion beyond equilibrium size. We quantify how much of a barrier island chain is drowned by calculating the fraction of its length that is below mean sea level due to sea level rise. Results show that barrier drowning is mostly sensitive to the wave height and the rate of sea level rise. In the model, it takes 100s of years for barrier islands to start drowning in response to high rates of sea level rise (more than 5 mm/yr, for a typical coastal environment). This lag in barrier response is caused by a gradual decrease in the sand volume of the barrier. Higher rates of sea level rise cause earlier and more severe barrier drowning. Modeled barrier systems that face higher waves undergo more frequent inlet closures that lower the rate of drowning, but they also have a deeper shoreface that increases the rate of drowning. In model simulations, the latter process dominates over the former when sea level rise rates exceed 5 mm/yr. Model results fairly agree with available field data. Plain Language Summary: In extreme sea level rise scenarios (like those predicted during the 21st century and beyond) barrier islands may drown. Barrier drowning occurs due to a lack of sediment induced by sea level rise, which causes submergence of (parts of) the barrier chain. It remains difficult to predict when and under which conditions drowning may occur. In this study we investigated the dynamics of drowning barrier islands with an exploratory numerical model. A key finding from our model is that high rates of sea level rise (higher than 5 mm/yr), but also high waves (higher than 1.5 m) result in barrier drowning. However, even under model simulations with high rates of sea level rise, it takes a long time for the sand in the barrier island to erode. Barrier drowning and disappearance therefore might take 100s of years. The model results are consistent with available field data, but more observations are needed to achieve a full model verification. Key Points: Idealized morphological model simulations show that tidal inlets expand until barrier islands disappear under rapid sea level riseModeled barrier drowning lags sea level rise acceleration by 100s of yearsLag in modeled barrier drowning is explained by a decrease in the sand volume of the barrier [ABSTRACT FROM AUTHOR]

Concerns were raised about possible behavioral disturbance to narwhals (Monodon monoceros) when exposed to shipping noise in Milne Inlet, Baffin Island, Canada. We deployed passive acoustic recorders in August and September 2018 and 2019, along and adjacent to the nominal shipping corridor. We measured broadband (0.01-25 kHz) sound pressure levels (SPL) after correcting for the auditory weighting function of high frequency cetaceans. Received SPLs and counts of Whistles, Buzzes, and Knocks were compared in a beforeduring-after study of individual bulk carrier transits, relative to periods with no ships. Narwhal call counts were generally lower once bulk carriers were within line-of-sight, including when ship noise levels were just above ambient noise levels. Call counts varied both "before" and "after" individual bulk carriers passed by the recorders. There was no evidence of a behavioral threshold SPL below which a response did not occur. We did not observe call count reductions to the same extent in 2019 compared to 2018 as higher ambient noise levels in 2019 likely masked some individual ship noise. There was no evidence of habituation or sensitization to the bulk carrier noise within or between years. Continued acoustic monitoring is recommended, especially if bulk carrier transits increase. [ABSTRACT FROM AUTHOR]

Analyzing the triple oxygen isotope (Δ′17O) composition of carbonates and air CO2 can provide valuable information about Earth system processes. However, accurately measuring the abundance of the rare 17O‐bearing CO2 isotopologue using isotope ratio mass spectrometry presents significant challenges. Consequently, alternative approaches, such as laser spectroscopy, have been developed. Here, we describe an adaptable dual inlet system for a tunable infrared laser direct absorption spectrometer (TILDAS) that maintains stable instrumental conditions for subsequent sample and reference measurements. We report ∆′17O measurements on three types of samples: reference CO2, CO2 derived from the acid digestion of carbonates, and air CO2. The external repeatability (±1σ) for reference‐sample‐reference bracketing measurements is generally better than ±10 ppm, close to the average internal error of ±6 ppm. Our results demonstrate that laser spectroscopy is a capable technique for measuring triple oxygen isotopes with the precision required to resolve variations in the ∆′17O values of air CO2 and to use the ∆′17O of carbonates for paleothermometry. Plain Language Summary: Tunable infrared laser direct absorption spectroscopy (TILDAS) is a technique that determines isotopologue abundances by shining a laser through the analyzed gas and measuring the amount of light absorbed. Laser spectroscopy is emerging as a competitive alternative to the more common isotope ratio mass spectrometry due to its ability to provide rapid and precise measurements of rare isotope ratios directly on CO2 gas. We present a cost‐effective dual inlet system for TILDAS to measure the triple oxygen isotope composition of carbonates and air CO2. Our setup maintains stable measurement conditions, for example, instrumental temperature, gas composition, pressure, and achieves external repeatability generally below ±10 ppm. Triple oxygen isotope measurements with such precision enable resolving variations in the 17O‐anomaly of air CO2 and using the ∆′17O values of carbonates for paleoenvironmental applications. Key Points: An inlet system using inexpensive hardware and open‐source software was developed for tunable infrared laser absorption spectroscopySpectroscopic measurements of ∆′17O in CO2 can be negatively influenced by variable temperatures, uneven CO2 mixing, which were addressedThe external standard deviation of repeated ∆′17O measurements of CO2 from carbonates and air was better than 10 ppm [ABSTRACT FROM AUTHOR]

Rationale: Microdroplet chemistry has attracted tremendous interest in recent years. We have previously reported that microdroplet mass spectrometry (MS) achieves reaction acceleration. Here we systematically investigated the effect of capillary heating of MS inlet and solvent polarity of microdroplets on the conversion ratios of dehydration and phosphorylation reactions. Methods: The micron‐sized droplets generated by high‐speed gas encapsulated the compounds. The conversion ratios of dehydration and phosphorylation reactions were investigated at different capillary temperatures of MS inlet between 30°C and 300°C. Subsequently, the effects of solvent polarity of different microdroplets (acetonitrile, acetonitrile/water [v/v: 9:1], and water) on microdroplet reactions were investigated. Results: The microdroplets could be used as reaction vessels for rapid dehydration and phosphorylation reactions. Microdroplet MS is characterized by the completion of the reaction in microseconds. The increase in capillary temperature increased the conversion ratio of dehydration reactions but had little effect on phosphorylation reactions. The stability of compounds supports this phenomenon. In addition, the increase in solvent polarity in microdroplets promoted the dehydration reaction but inhibited the nucleophilic substitution reaction (phosphorylation reaction). Conclusions: Microdroplet MS achieved an acceleration of the reaction, which was attributed to capillary temperature, microdroplet solvents, and the stability of reaction products. This finding suggested that the inlet capillary and solvent system should be considered in the study and interpretation of microdroplet MS. [ABSTRACT FROM AUTHOR]

Flow maldistribution at the inlet of a heat exchanger (HX) is a significant parameter that needs to be considered to judge the performance of the same. In this paper, four arrangements of three‐fluid cross‐flow heat exchanger (3FCFHX) with different flow conditions are considered as shown in Figure 1 in which is the performance of cross‐countercurrent and cross‐cocurrent arrangements for uniform and flow maldistribution at the inlet. In addition, the effect of different inlet fluid flow models on the HX performance are investigated numerically. Among the three fluids in these arrangements, the central fluid is considered to be the hot fluid. From the principles of conservation of energy, the governing equations for three fluids are generated and solved using the finite element method. Four different inlet fluid‐flow models are considered for the analysis. Performance is judged using hot fluid effectiveness and the number of transfer units for a different range of governing parameters. The effects of inlet flow maldistribution (IFM) are measured using degradation factors. The results show that the performance of cross‐cocurrent arrangement is found to be superior to the cross‐countercurrent arrangement. In addition, the IFM enhances thermal performance. Further, it is determined that the flow maldistribution at the inlet will enhance the hot fluid effectiveness by 4%–4.5% and 1.8%–2% in cross‐cocurrent and countercurrent arrangements, respectively. The results give a thorough insight into the significant concerns involved in the design of such HXs. Application of the finite element method proves the ease of determining the exit temperatures of the fluids in the HX. This approach is indeed time‐saving and gives insights when compared to the CFD approach. [ABSTRACT FROM AUTHOR]

Multisensory stimuli provide organisms with information to assess the threat present in the surroundings. Olfactory cues show dominance over other sensory modalities in the aquatic environment. The impact of chemical predator cues combined with experiences gained (learning) in species without previous contact is not fully understood. We investigated the foraging and shelter‐seeking behaviour of naïve and experienced marbled crayfish Procambarus virginalis juveniles in response to the chemical signals of pumpkinseed Lepomis gibbosus alone and in combination with alarm chemicals produced by preyed‐upon conspecifics. Naïve and experienced (previously exposed to pumpkinseed predation) juveniles were stocked in an arena with shelter and feed and exposed (1) to water from a tank containing a predator actively feeding on conspecifics, (2) water from a tank with predator only and (3) water only as control. Crayfish exposed to the combined stimuli avoided the inlet zone and gravitated to shelter zone of the arena to a greater extent than did those exposed to predator‐only cues and the control. Regardless of the treatment, experienced crayfish showed significantly reduced interest in feeding. Our findings imply that crayfish response to threat‐associated odours with the greatest potency when visual or tactile cues are present, while previous encounters with predators may make them more cautious. [ABSTRACT FROM AUTHOR]

Aiming at the problem of performance degradation of flue gas acid‐making control system caused by system uncertainty and external interference, this paper presents a model predictive control scheme based on an equivalent input disturbance (MPC‐EID) for the temperature tracking control of flue gas acid production systems. First, a nonlinear Wiener model is established for the process, which can well character the nonlinear change of process temperature. Second, design the overall control strategy and complete the design of MPC and EID, the observer estimates the equivalent input disturbance, and compensates the estimated value in a feed‐forward manner to obtain the final composite control rate to achieve the rapidity, accuracy and robustness to the disturbance of the reference temperature tracking. Third, a rigorous stability analysis shows that the closed‐loop system is stable. Finally, simulation and experimental results demonstrate that the MPC combined with EID method is more efficient compared with MPC and MPC‐PID approaches. [ABSTRACT FROM AUTHOR]

Chaetognaths (Phylum: Chaetognatha) are one of the most abundant phyla of zooplankton worldwide and play an important role in marine trophic interactions. Although the role of chaetognaths in global ecosystems is well understood, the spatial variation and environmental drivers of estuarine chaetognath populations is poorly understood. To provide the first known record of chaetognath species composition in a coastal estuary in the south‐eastern USA, chaetognaths were identified and quantified from zooplankton samples collected on a monthly basis in 2019 and 2020 from North Inlet Estuary in South Carolina. Parasagitta tenuis was the most abundant species of the five found, making up 33% of total abundance. The egg presence of these chaetognaths was further analyzed to gauge reproductive cycles. Abundance and egg presence were compared with surface and bottom measurements of temperature, salinity, and dissolved oxygen levels to determine the driving abiotic factors behind chaetognath's seasonal variability and reproductive cycles. Temperature, salinity, and dissolved oxygen all had low (r < ±.29), non‐significant correlations with abundance. Chaetognath egg production was most significantly associated with dissolved oxygen (p <.001) and seasonal changes in temperature (p <.001). Our initial findings indicate the continued abundance of chaetognath in a local estuary are dependent on abiotic factors that are strongly influenced by a changing climate. [ABSTRACT FROM AUTHOR]

Wildlife researchers need to understand the effects of biotelemetry tags in order to better weigh benefits versus risks. We describe tag‐site healing and pathology of three beluga whales, Delphinapterus leucas, found dead in Alaska. The tags were secured with two or three nylon rods that pierced the dorsal ridge, and one beluga also had a LIMPET tag. The tag wounds in one Cook Inlet beluga featured a normal healing response with minimal inflammation ~12 years posttagging. Photo‐ID studies of another Cook Inlet beluga demonstrated degeneration of the tag wounds over several years. It died ~12.8 years posttagging of bronchopneumonia and septicemia due to Staphylococcus aureus that also infected the tag wound. A Bristol Bay beluga died 4 months posttagging. Although it may have been predated by a killer whale attack, Orcinus orca, the tag site was inflamed and infected with Streptococcus uberis which spread to an abscessed lymph node. To reduce the risk of infection, researchers should adopt strict sterilization protocols for all implanted parts of tags and continue research into improved tagging methods. Clinical and behavioral assessment of potential preexisting conditions before tag deployment, as well as posttag monitoring, could help reduce tag‐associated mortality and identify immediate impacts and mortality. [ABSTRACT FROM AUTHOR]

Key Clinical Message: We present a case of a medically resistant cervical inlet patch causing persistent globus and symptoms of laryngo‐pharyngeal reflux, successfully treated with CO2 laser ablation. [ABSTRACT FROM AUTHOR]

Introduction: To determine whether a pelvis is wide enough for spontaneous delivery has long been the subject of obstetric research. A number of variables have been proposed as predictors, all with limited accuracy. In this study, we use a novel three‐dimensional (3D) method to measure the female pelvis and assess which pelvic features influence birth mode. We compare the 3D pelvic morphology of women who delivered vaginally, women who had cesarean sections, and nulliparous women. The aim of this study is to identify differences in pelvic morphology between these groups. Material and methods: This observational study included women aged 50 years and older who underwent a CT scan of the pelvis for any medical indication. We recorded biometric data including height, weight, and age, and obtained the obstetric history. The bony pelvis was extracted from the CT scans and reconstructed in three dimensions. By placing 274 landmarks on each surface model, the pelvises were measured in detail. The pelvic inlet was measured using 32 landmarks. The trial was registered at the German Clinical Trials Register DRKS (DRKS00017690). Results: For this study, 206 women were screened. Exclusion criteria were foreign material in the bony pelvis, unknown birth mode, and exclusively preterm births. Women who had both a vaginal birth and a cesarean section were excluded from the group comparison. We compared the pelvises of 177 women between three groups divided by obstetric history: vaginal births only (n = 118), cesarean sections only (n = 21), and nulliparous women (n = 38). The inlet area was significantly smaller in the cesarean section group (mean = 126.3 cm2) compared with the vaginal birth group (mean = 134.9 cm2, p = 0.002). The nulliparous women were used as a control group: there was no statistically significant difference in pelvic inlet area between the nulliparous and vaginal birth groups. Conclusions: By placing 274 landmarks on a pelvis reconstructed in 3D, a very precise measurement of the morphology of the pelvis is possible. We identified a significant difference in pelvic inlet area between women with vaginal delivery and those with cesarean section. A unique feature of this study is the method of measurement of the bony pelvis that goes beyond linear distance measurements as used in previous pelvimetric studies. [ABSTRACT FROM AUTHOR]

There is widespread concern that rapidly rising sea levels may drown salt marshes by exceeding the rate at which these important ecosystems can build elevation. A significant fraction of marshes reside within backbarrier estuaries, yet little attention has been paid to how changes in inlet geometry influences estuarine tides and marshes. In 1898, a coastal storm eroded a new inlet through the barrier beach that fronts the North‐South Rivers Estuary in Massachusetts, USA. The new inlet shortened the North River by 5.6 km and lengthened the South River channel by the same amount. Modern measurements of tidal attenuation suggest that channel shortening abruptly increased mean high tide along the North River by at least 30 cm. Foraminifera communities within North River marsh sediments indicated an environmental change from infrequent to frequent inundation at the time of the 1898 switch in inlet location, which supports this hypothesis. Increased mineral sediment deposition after the inlet switch played a dominant role in allowing marshes along the North River channel to adjust to greater inundation. Following the inlet switch, sediment accreted in North River marshes at 2–5 times the rate of sea level rise (SLR). The North River channel widened by an average of 18% relative to pre‐1898 conditions to accommodate the increased tidal prism. The role of mineral sediment accretion in making this marsh resilient to an abrupt increase in inundation depth highlights the importance of maintaining adequate sediment supplies in coastal regions as SLR accelerates. Plain Language Summary: Salt marshes form along sheltered coastlines, incorporating mud and dead roots atop a grassy platform at about the elevation of high tide. It is unclear whether marshes will build their platforms fast enough to keep up with expected increases in sea level. In 1898, a coastal storm eroded a new opening in a beach, behind which a salt marsh extends inland along two tidal channels. The new inlet shortened the distance from the open ocean to parts of the salt marsh, causing high tides that flood the salt marsh to increase more than 30 cm. We considered this "natural experiment" in increased tidal flooding to understand how other marshes might survive rapid sea level rise (SLR). Sediment core samples from the marsh showed that higher tides after the inlet switch resulted in lots of mineral sediment deposited on the marsh platform. This shows that mineral sediment is very important to salt marsh survival when sea level is rising fast. Increased tidal flow after the inlet switch eroded and widened channels. Some of that eroded channel bank sediment deposited atop the marsh, but most of the sediment that allowed the marsh to survive rapid SLR came from the ocean. Key Points: Inlet and barrier dynamics can have first order controls on tidal propagation and impacts to marshesDeposition rates three to five times the rate of sea level rise (SLR) allowed for continued marsh resilienceMinerogenic sediment supply allowed for marsh resilience under rapid rates of effective SLR [ABSTRACT FROM AUTHOR]

The ancient surface of Mars is dominated by degraded impact craters with reduced or eliminated rim relief. Some degraded craters have an inlet valley, while many remain fluvially isolated. Despite controlling Martian fluvial connectivity, few constraints exist on why some—but not all—degraded craters possess inlets. We compared a suite of properties around degraded Martian craters with and without inlets to ascertain what topographic and hydrologic factors influenced inlet formation. Slope and surface roughness are similar, but topographic inset within the catchment, drainage density, and potential contributing areas diverge for breached and non‐breached craters. We suggest that the importance of basin hydrology‐related factors over topographic factors is the result of the former less frequently surpassing inlet incision thresholds than the latter. We conclude that greater topographic inset (i.e., craters deeper within regional depressions) promoted higher discharge, and that inlet valley formation was ultimately controlled by Mars' crater‐dominated topography. Plain Language Summary: The ancient surface of Mars is dominated by impact craters that have been modified by mass wasting, aeolian infilling, water activity, and subsequent impact cratering. Erosion has lowered or eliminated the relief of many craters' rims, resulting in "degraded" craters. On early Mars, water activity also led to the formation of branching valley networks, which flow into some Martian impact craters. However, many degraded craters remain without an inlet valley. Inlet formation reveals that water activity could overcome the disruption of topography caused by impact crater formation. Yet, little is known about factors that would promote or limit inlet valley formation and it is unclear why some—but not all—degraded craters were breached by inlet valleys on Mars. We compared a suite of properties around degraded Martian craters with and without inlets to find out what topographic (e.g., slope) and hydrologic factors (e.g., the number of valleys per area) affected inlet formation. We find that hydrology‐related factors are very different between craters with and without inlets, while topographic factors are similar. Our results suggest that inlet valley formation was ultimately controlled by hydrologic routing on Mars' crater‐dominated surface. Key Points: We compared slope, roughness, drainage density, and catchment geometry around degraded Martian craters with and without an inlet valleyOnly relative topographic inset, drainage density, and potential contributing area differ between the breached and non‐breached subsetWe conclude that more inset craters (i.e., deeper or more central in a basin) received greater discharge which promoted inlet breaching [ABSTRACT FROM AUTHOR]

The shear effect of co‐currently flowing water on the flow instabilities induced by swirling steam was investigated. With shear, a 22–27 % decrease in velocity fluctuation amplitude was observed. The decrease was 29–41 % on an exponential and 12–17 % on a proportional basis. Shear reduced the layer thickness on increasing the inlet water pressure from 1 to 2 bar by 1.9–2.9 and 6.35–12.89 % at steam inlet pressures of 1 and 2 bar, respectively. The ratio of the swirl intensity along the dimensionless axial length scale and the initial swirl intensity was changed from < 1 to > 1 across critical point due to the nearly equal values of buoyancy and rotational frequencies. A critical limit of the initial swirl intensity within the control plane was investigated wherein the swirl‐induced instabilities can be attenuated uniformly and the rotational effects dominate over the gravity waves and buoyancy. [ABSTRACT FROM AUTHOR]

The performance and flow field of large‐scale cyclones with different inlet numbers were investigated by using computational fluid dynamics methods. The results show that the efficiency, pressure drop, and performance factor of cyclones increase with the increase in the number of inlets, and the quadruple inlet cyclone having the best overall performance is supposed to adopt. The number of inlets of the cyclone increases, the tangential velocity increases, and the short‐circuit flow rate decreases; however, when the number of inlets is greater than 2, both variations are lessened. In this study, the vortex eccentricity of the quadruple inlet cyclone is the smallest, the vortex eccentricity of the double and triple inlet cyclone is comparable, and the vortex eccentricity of the single inlet cyclone is the most significant. [ABSTRACT FROM AUTHOR]

In the existing ventilation design, the ventilation rate is defined by the time‐averaged flow rate, and the fluctuating (turbulence) component is not typically considered. However, inlet turbulent conditions are also assumed to have some influence on the formation of contaminant distributions. Therefore, the influence of turbulent kinetic energy at the inlet boundary on scalar transportation in an indoor environment needs to be elucidated when discussing the ventilation rate setpoint via the supply inlet in terms of local contaminant concentration control. This study discusses the impact of turbulent kinetic energy in the ventilation design on scalar transfer and its distribution within an enclosed space. To understand the influence of various inlet turbulent boundary conditions on scalar transfer, a computational fluid dynamics analysis was conducted using two different room models: a simple room and a room with a ventilation system that creates a large velocity gradient. The results indicate that scalar transfer within the room is not solely dominated by the averaged velocity input at the inlet boundary but is also strongly affected by the turbulence conditions at the inlet boundary. The numerical results indicate the possibility of a new ventilation design strategy that simultaneously considers the transfer of turbulent components and contaminants. [ABSTRACT FROM AUTHOR]

High‐speed water jets are key technologies for increased production efficiency in oil drilling, and high‐speed self‐excited oscillating pulsed water jets (SEOPWs) offer many advantages compared to continuous jets for most industrial applications. Therefore, many studies have focused on this topic. However, the current studies on hydraulic pulsed jets have rarely extended to integrated modeling of the high‐speed water jet transmission process. To better apply the SEOPWs, based on fluid mechanics, the theoretical model of the plunger pump–pipeline–nozzle is established, and the sensitivity of different nozzles on the pulsating fluid is studied in the time domain. Furthermore, the vibration characteristics of the nozzle are further investigated in the frequency domain. The results show that the common nozzle has an enlarged role in the pressure amplitude, the Helmholtz nozzle enlarges the pressure peak and amplitude, and the amplification is more obvious with the speedy growth on the plunger pump. However, as the pipeline becomes longer, the difference between the pressure of the inlet and outlet does not change. Therefore, the nozzle is more sensitive to the change in the plunger pump speed. In the frequency domain, the secondary frequency peak for the Helmholtz nozzle is 1.26 times larger than the interference frequency, while it is 1.08 times for the common nozzle. Helmholtz nozzles tend to produce stronger natural vibrations than common nozzles. By comparing the impact force, the experimental results show good agreement with the simulated results. The study provides a theoretical basis for water jet‐assisted drilling in deep wells and lays the foundation for the better application of self‐oscillating impact drilling tools. [ABSTRACT FROM AUTHOR]

Wind influence on tidal inlet hydrodynamics is examined using 40 days of wind, water level, and current observations collected in Spring 2019 at Oregon Inlet, NC, a large (1 km wide, 1–13 m deep) meso‐tidal inlet with complex delta systems. Wind velocities through the inlet (ranging 0–18 m/s) are modulated at subtidal timescales and are well correlated (R = 0.87) to a subtidal component of the water level slope through the inlet. The subtidal wind and water level slope are also well correlated to the subtidal current along the principal flow axis in the main inlet channel (R = 0.92 and 0.96, respectively). In combination with findings from previous studies, these findings suggest that regional winds induce the subtidal water level slope through the inlet by causing opposing setup/setdown to either side of the inlet. A force balance at the inlet demonstrates that the wind‐induced pressure gradient forces the subtidal currents, with wave forcing and local wind shear acting as lower‐order influences. The magnitude of the subtidal current is substantial, exceeding that of the tidal currents 45% of the time. Cumulatively, these findings indicate that regional winds exert a first‐order control on the currents at Oregon Inlet and cause irregular hydrodynamic patterns not well described by the traditional inlet classification scheme. Regional geographic characteristics may contribute to the high level of wind influence at Oregon Inlet, but similar processes are likely to be important to net flow dynamics at other inlets with large, shallow inland water bodies. Plain Language Summary: Tidal inlets are constricted coastal channels maintained by the flow and are particularly common along barrier island systems where they have important implications for the flux of sediments along the coast. The traditional tidal inlet classification system is based on the relative strength of tides and waves; however, mounting evidence suggests winds may also be an important control of inlet dynamics. This works uses observations of winds, currents, and changes in water levels at Oregon Inlet, NC, to examine the role of local and regional winds in altering tidal inlet currents. Results suggest that regional winds induce a water level gradient through the inlet that varies over time periods longer than tides (>12 hr), and that this gradient then forces a current through the inlet over the same timescales. The magnitude of the wind induced current exceeds that of the tidal current 45% of the time and far exceeds contributions from waves, implying that winds may play an underappreciated role in tidal inlet dynamics. Improving our understanding of wind control on tidal inlets has important implications for dredging efforts common to tidal inlets, for numerical models simulating island chain evolution, and to the navigation of vessels that use charts to determine times of safe transit based on expected water levels and currents. Key Points: Observational data suggest regional winds induce a water level gradient through Oregon Inlet that varies over subtidal time scalesSubtidal water level gradients induced by regional winds account for 92% of the variance of along‐inlet subtidal currentsSubtidal currents through the inlet are of the same order as the tidally driven currents and exceed the tidal currents 45% of the time [ABSTRACT FROM AUTHOR]

The physical, sedimentological, mineralogical and elemental geochemical properties of sediment cores AMD1803‐02BC and 01PC from the Cape Norton Shaw Inlet were investigated to reconstruct glacial sediment discharges from southeastern Manson Icefield and document the impact of ice–ocean interactions on the sediment dynamics and opening of the North Water Polynya (NOW) in northwestern Baffin Bay since the last deglaciation. Laminated glaciomarine sediments rich in quartz and feldspar are observed prior to 11 cal. ka BP and were probably deposited by hyperpycnal currents triggered by the local retreat of the southern margin of the Innuitian Ice. Detrital proxies suggest that Early Holocene sediment dynamics were mainly influenced by sea ice and iceberg rafting and meltwater discharges related to the deglaciation of eastern Smith (~11 to 10.65 cal. ka BP) and Jones (~10.7 cal. ka BP) sounds. This also provides an upper limit to the timing of formation of the NOW. The high detrital carbonate contents during 8.8 to 6.6 cal. ka BP confirm that enhanced carbonate‐rich sediment export from Nares Strait to northern Baffin Bay occurred during and after the deglaciation of Kennedy Channel (8.8 to 8.2 cal. ka BP). Canadian Shield sediment inputs have dominated since 6.6 cal. ka BP, indicating that sedimentation is mainly influenced by Cape Norton Shaw glacier discharges. The lower level of sedimentation recorded in core 01PC during the Middle to Late Holocene suggests an accelerated landward retreat of the Cape Norton Shaw glaciers in response to warmer marine conditions. During the Neoglacial period, higher sedimentation rates and detrital proxies in the cores suggest increased glacial erosional processes, probably associated with the long‐term declines in boreal summer insolation and glacier growth. Finally, mineralogical and grain‐size data in core 02BC support the idea that increased Arctic atmospheric temperatures have had an important influence on the glacial dynamics during the industrial period. [ABSTRACT FROM AUTHOR]

The ability to manipulate drops is essential for integrating multiple processes in droplet microfluidics‐based lab‐on‐a‐chip devices. Examples of such droplet manipulation operations include sorting, sequencing, synchronization, and so forth. Microfluidic networks are promising platforms for performing these functionalities. This work explores the design of entry times of drops, a set of operating parameters, in a microfluidic network to achieve a desired functionality. Here, we specifically focus on sorting of drops at the exit of the network. For the first time, droplet microfluidic networks are perceived as hybrid dynamical systems. This viewpoint allows us to develop a methodology for designing the entry times of drops in microfluidic networks to achieve desired functionalities through the notion of constraint satisfaction. The solution to this constraint satisfaction problem provides entry times that result in the desired functionality. The proposed method allows one to establish the existence/nonexistence of entry time solutions for a desired functionality. [ABSTRACT FROM AUTHOR]

Tidal currents are predominant in coastal areas, causing the generation of vortices at different scales. We reproduce the main process of vortex shedding generated in tidal systems with inlets and channels using a laboratory large‐scale model. A filter‐space technique is implemented to analyze nonlinear energy/enstrophy transfer rates and map out the energy pathways through the flow scales of the measured velocity fields. We provide sound evidence of the transitional character of the energy cascades during a tidal period. The periodic generation and destruction of tidal vortices plays a relevant role in the transition from an inverse to a direct energy cascade within a tidal period. The period‐averaged energy budget shows the coexistence of multiple cascades. Small scales follow a direct energy cascade, whereas a split‐energy cascade is found at intermediate and large scales, where part of the injected energy goes to small scales and part to a larger flow scale. Plain Language Summary: Remote sensing images from a satellite of ocean and coastal areas offer unique opportunities to observe vortical flow structures. Coastal areas are often dominated by tidal currents that interact with coastline features (island, headlands or capes, and inlets) and periodically shed vortices at different scales. Coastal vortices are known to play a fundamental role in momentum, mass, and energy transport. Understanding how energy is exchanged among the wide range of flow scales (small/large vortices and large‐scale tidal circulations) is a fundamental question that deserves a thorough investigation, owing to the great impact on the coastal dynamics. With this in mind, we used a large‐scale physical model to accurately recreate the main processes that lead to the generation of tidal vortices observed around natural inlets. The measured velocity fields have been analyzed with filtering techniques that allow for understanding the direction of energy exchanges. We demonstrated that the periodicity of the tidal flow produces multiple energy cascades depending on the tidal phase. We found that energy followed dual pathways toward large scales and vice versa. Key Points: We recreate the generation of tidal vortices at different scales around tidal inlets using a laboratory modelVortices shed around the inlet undergo a merging‐thinning process leading to macro flow gyres that occupy the entire tidal flatsThe results of filter‐space analysis demonstrate the coexistence of energy and enstrophy multiple cascades depending on the tidal phase [ABSTRACT FROM AUTHOR]

Rationale: Resolution and sensitivity are two key parameters for describing the performance of high‐field asymmetric waveform ion mobility spectrometry (FAIMS). An increase in the resolving power of FAIMS has been realized by adding helium to nitrogen in planar FAIMS, but it comes at the expense of sensitivity. Methods: Here, a new hollow needle‐to‐ring discharge device integrated on a PCB substrate is used as the ion source for FAIMS. Helium flows from the hollow part of the hollow needle to improve the ionization effect. Nitrogen carries the sample into the ionization chamber and is mixed with helium as the carrier gas. Results: Under a nitrogen flow rate of 1 L min−1, 1.5 L min−1, 2 L min−1, and 2.5 L min−1, adding helium at different flow rates (0.2 L min−1, 0.3 L min−1, 0.5 L min−1, and 1 L min−1) can simultaneously improve the separation ability and sensitivity. Helium and nitrogen with flow rates of 0.2, 0.3, 0.5, and 1 L min−1 were added to nitrogen (2 L min−1). The separation ability and sensitivity of the mixed gases doped with helium are better than those of nitrogen. The larger the RF voltage amplitude is, the more obvious the improvement in the separation ability when helium is added. However, helium doping has the opposite effect on the sensitivity. Conclusions: This study provides a new idea and technical means for the application of helium and nitrogen gas mixtures in planar FAIMS. This method can greatly improve the performance of FAIMS. [ABSTRACT FROM AUTHOR]

Our aim is to analyze special type of boundary conditions, created to simulate flows like in cardiovascular and respiratory systems. First, we will describe model of viscous, incompressible fluid in a domain consisting many inlets and outlets with open dissipative boundary conditions. The conditions are augmented by the inertia terms. We are posing additional constrains on a fluid motion by a volumetric flow rates or inlet/outlet pressure. Afterwards, we will define weak formulation of the problem and its motivation. Then, we will prove mathematical correctness of proposed conditions by properly modified Galerkin method. Also, we will prove existence of a solution and its uniqueness. [ABSTRACT FROM AUTHOR]

The increasing temperature of lithium‐ion batteries during charging and discharging affects its operational performance. The current studies mainly adopt simplified model, less considering the effect of the battery internal electrochemical reaction on the air cooling performance, and the air cooling structure needs to be further optimized. In order to solve the problems above, the coupled electrochemical‐thermal air cooling model was established, and the air cooling structure was optimized in terms of the relative position and height of the battery pack inlet and outlet, the distribution, and spacing of cells. The results show the better air cooling performance is achieved when the inlet and outlet are aligned on the same side. When the lateral inlet and outlet aligned on the same side, the lower outlet height is more important for improving the heat dissipation performance of the battery pack, but the worse temperature uniformity emerges. According to the cooling performance of different positions in the battery pack, a method for nonequidistant symmetrical distribution of cells is able to improve the temperature uniformity. The optimal combination of the air cooling structure with various factors is obtained. [ABSTRACT FROM AUTHOR]

Large equipment items, such as distillation column systems, compressors, or major pressure vessels, are commonly protected by multiple pressure relief devices mounted on a common inlet manifold. In selecting this type of design, the potential exists to inadvertently overlook the flow characteristics associated with such a common inlet manifold. The methodology discussed in this paper should effectively model flow through multiple pressure relief devices mounted on common inlet manifolds. This approach ensures accurate representation of flow through each pressure relief device while avoiding the potential pitfalls of taking shortcuts by only analyzing flow through one device. [ABSTRACT FROM AUTHOR]

GWK+: extension of the large wave flume in Hannover – analysis of current inlet The necessary expansion of maritime renewable energies requires the detailed investigation of structural load limits and potential environmental impacts of offshore structures. Large‐scale test facilities play an important role in this context, as they provide the rare opportunity to investigate offshore structures in large scale under realistic conditions. Of particular importance for the design of offshore structures is a realistic representation of the complex superposition of waves and currents, which is currently only possible in a few large‐scale test facilities. With the extension of the large wave flume (GWK) in Hannover to the GWK+, the first test facility of this kind in Germany will be available from 2022. The design and construction of an additional current inlet into a wave channel represents a major technical challenge. The design of the current inlet must ensure that flow conditions similar to those in nature can be reproduced in the study area of the wave channel. As an essential flow component, this paper will therefore describe the development of the current inlet into the extended GWK from the design stage to further optimization by means of a 1:10 model created specifically for this purpose. Insights into the implementation, the flow‐related challenges as well as the optimization of the current inlet into the wave flume by means of guiding walls and adjustable guiding vanes, and the general suitability for the approximation of the vertical velocity profile as a 1/15 law are presented. [ABSTRACT FROM AUTHOR]

Cyclone separators play a dominating role in fluid catalytic cracking, biomass pyrolysis, dedusting, demisting, heavy oil regrading, etc. Separation mechanism, pressure drop, particle size, collection efficiency, gas underflow, gas inlet velocity, particle loading, cut‐off size of particles, and gas residence time are the main cyclone performance criteria. In the present work, the particle separation theory is explained and recent developments of numerical simulations of different cyclone separators with tangential inlet are summarized. Besides, the effect of different parameters on cyclone performance is discussed and several suggestions are provided based on previous numerical simulations. [ABSTRACT FROM AUTHOR]

Due to its high thermal sensitivity, a power lithium‐ion battery for vehicles requires an efficient cooling system to ensure safety and good performance. Excellent heat dissipation capacity enables the liquid cold plate cooling system to have better application prospects. However, all existing cold plates improve their cooling capacity by increasing the complexity of their structure. Therefore, directly opposite inlet and outlet cavity cold plate cooling systems with simple structures are established. Two kinds of cavity cold plates (Model I and Model L) with different inlet and outlet positions are analyzed using the numerical simulation method. The effects of inlet and outlet sizes, coolant mass flow rate (qm), and inlet and outlet positions on the temperature field as well as the cold plate pressure drop are studied. According to the results, maximum temperatures of batteries appear at four corners of cavity cold plates, which are lower than 35 °C. The cooling capacity and temperature uniformity of Model I cooling systems are better than those of Model L. However, the heat dissipation capacity of Model L is more sensitive to qm than that of Model I. Pressure drop of Model L is smaller. This method meets the heat dissipation of vehicle pouch lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

In this paper, experimental investigations on droplet separation in the feed inlet area of a distillation column are presented. For this purpose, the qualitative entrainment for different droplet separators of a distillation column was measured qualitatively in a pilot scale test rig. The results are discussed and evaluated in this paper with respect to their significance for the prevention of entrainment in the feed section. In addition, a short outlook on simulation‐based determination of entrainment is given. [ABSTRACT FROM AUTHOR]

Many micromixing applications require simple structured passive mixers rather than complex structured passive or expensive active mixers. However, mixing quality in a typical simple structured passive mixer remains poor. In the present work, simple T‐type micromixer is modified with a circumferential in‐step at the entry of inlet channels to generate velocity components oblique to the mainstream inlet flow. The performance of T and T–T mixers with and without circumferential in‐step has been estimated for various Re (0 to 700). Results showed that inlet sample flow achieved velocity components of three‐dimensional nature with circumferential in‐step, leading to a momentous degree of intertwinement and entanglement of samples during the collision at the confluence of inlet channels. As a result, a remarkable improvement in mixing is obtained in the presence of in‐step for sufficiently higher flow rates of Re above 100 by T‐mixer and Re above 300 by T–T mixer. In particular, T‐mixer offers better advantage with in‐step compared to T–T mixer; marking an improvement for Re as low as 100 and above, as well as exhibiting shorter mixing lengths. Therefore, the present design of simple structured T‐mixer with in‐step at entry can be an effective device for various micromixing applications. [ABSTRACT FROM AUTHOR]