Dry Core Research Articles

Valorization of Pineapple Core Waste for Sequential Extraction of Phenolic Compounds and Carotenoids: Optimization Through Ultrasound-Assisted Method and Box–Behnken Design

AbstractIn this study, a pioneering cascade method involving ultrasound-assisted extraction (UAE) and Box–Behnken Design (BBD) was optimized to valorize pineapple core waste by the sequential extraction of, firstly phenolic compounds and, secondly, carotenoids. The effectiveness of the extraction was evaluated based on total polyphenol content (TPC) and antioxidant activity using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Characterization of the carotenoids was performed using high-performance liquid chromatography with a diode array detector (HPLC–DAD). The initial characterization of dry pineapple core (DPC) samples revealed their nutritional composition, including protein, lipid, and carbohydrate weight percentages of 1.20 ± 0.05%, 5.3 ± 0.4%, and 88.6 ± 0.5%, respectively. The high extractives content (40.0 ± 4.5%) suggests a substantial presence of phenolic compounds, making the pineapple core a valuable source of natural antioxidants. The optimal UAE conditions for phenolic compound extraction were 70% amplitude, 5 min extraction time, and 2 cycles, yielding an antioxidant extract rich in phenolic compounds with a desirability value of 81.2%. Therefore, DPC was considered a valuable source of natural antioxidants. The extraction of β-carotene also showed promising results with optimal UAE conditions of 20% amplitude, 3 min extraction time, and 2 cycles. This research promotes the sustainable use of pineapple waste and demonstrates the potential to obtain valuable additives for the food, pharmaceutical, and cosmetic industries, encouraging a more circular and efficient use of resources in the pineapple processing industry.

Sensor-Based and Visual Behavioral Profiling of Dry Holstein Cows Presenting Distinct Median Core Body Temperatures

The consequences of heat stress during the dry period can extend into the postpartum period, affecting health and productivity in the subsequent lactation. We hypothesized that cows with distinct core body temperatures (CBTs) would exhibit disparate behaviors associated with different degrees of heat generation or dissipation. The primary objective was to investigate behavioral differences of dry Holstein cows (n = 50) classified as high-temperature (HT) or low-temperature (LT), based on median CBT during the summer months using visual observations and accelerometer technology. A secondary objective was to investigate the transcriptome of white blood cells (WBCs) collected from a subgroup of HT and LT cows (n = 5; per group). Minor behavior differences were observed during the visual observations (performed for a total of 16h/cow). Based on automated monitoring system (AMS) data, collected 24/7 over a period of 42 days per cow, HT cows displayed higher periods of high activity and lower periods of inactivity prepartum and diminished rumination time postpartum than LT cows. There were 16 differently expressed genes (DEGs) in WBCs of HT compared to LT cows. Several of the identified DEGs have been previously associated with heat stress. The observed trends in the AMS data indicate that CBT and patterns of activity prepartum may serve as valuable predictors for identifying dairy cows with distinct tolerance to heat stress.

A review on antitumor effect of pachymic acid.

Poria cocos, also known as Jade Ling and Songbai taro, is a dry fungus core for Wolfiporia cocos, which is parasitic on the roots of pine trees. The ancients called it "medicine of four seasons" because of its extensive effect and ability to be combined with many medicines. Pachymic acid (PA) is one of the main biological compounds of Poria cocos. Research has shown that PA has various pharmacological properties, including anti-inflammatory and antioxidant. PA has recently attracted much attention due to its anticancer properties. Researchers have found that PA showed anticancer activity by regulating apoptosis and the cell cycle in vitro and in vivo. Using PA with anticancer drugs, radiotherapy, and biomaterials could also improve the sensitivity of cancer cells and delay the progression of cancer. The purpose of this review was to summarize the anticancer mechanism of PA by referencing the published documents. A review of the collected data indicated that PA had the potential to be developed into an effective anticancer agent.

Moisture sorption and mechanical properties of polymer-cement waterproofing membranes investigated by LF NMR

This study investigates the impacts of environmental humidity on moisture absorption and mechanical properties of polymer-based waterproofing membranes. Membranes of polymer-CaCO3, polymer-white cement composites and pure polymer were used for measurements after treated in different relative humidities (RHs). Results indicate that the humidity treatment greatly changes the mechanical properties of the membranes and increasing RH from 0 % to 100 % leads to reduction of tensile strength by 60–80 %, which is believed to originate from the plasticizing effect of the absorbed moisture. LF NMR (Low field NMR) enables quantification of moisture distribution in the polymer-filler composites and three types of water, i.e. the water stored inside polymer matrix (O/O water), the water located in interfacial regions between polymer phase and fillers (I/O water), and the free water in air voids are detected with increasing T2 values. The absorbed moisture majorly accumulates in the O/O interfacial region during the humidity treatments with RH of 0∼80 %, which is because of the larger O/O interfacial area compared with the I/O interface. A large amount of free water appears only at RH of 100 %. A core-shell structure of the polymer domains with dry core and moisturized shell, is interestingly found during the moisture absorption process of the membranes, based on the LF NMR measurements using MSE sequence. It is surprisingly found that the drop of tensile strength of the membranes upon moisture absorption is majorly related to the growing shell thickness of the polymer domains whereas the moisture accumulated in the I/O interfacial region plays a minor role.

Comparative evaluation of pore volume compressibility of carbonate reservoir rocks: different laboratory measurement approaches

The pore volume compressibility (C PV) of a reservoir plays an essential role in estimating the reserve oil and recovery factor. Therefore, selecting an appropriate laboratory measurement approach for determining the C PV is crucial. This study aims to compare three different routine approaches to C PV measurement. Fifty-eight carbonate core plug samples with diverse porosity from the Sarvak Formation in the Southwest of Iran were selected. The measurements were performed at different saturation, pressure, and temperature conditions in triaxial core holders. Results show that samples with the lowest porosity have the highest compressibility value, and samples with the highest porosity have the lowest value. Furthermore, the compressibility measured on brine-saturated cores at pressure and temperature conditions was higher than only brine-saturated, and consequently higher than dry core plugs. Hence, the measurement methods and approaches severely affect the resultant compressibility. The values obtained at representative reservoir conditions are advised to be utilized in simulation and modeling studies. A novel reciprocal model was also proposed to appropriately correlate the data with porosity. The results of this work give insight into the selection of the best laboratory measurement approach to estimate the actual C PV value in reservoir conditions, especially at varying pore pressure and temperature.

Mixed-precision computing in the GRIST dynamical core for weather and climate modelling

Abstract. Atmosphere modelling applications are becoming increasingly memory-bound due to the inconsistent development rates between processor speeds and memory bandwidth. In this study, we mitigate memory bottlenecks and reduce the computational load of the Global–Regional Integrated Forecast System (GRIST) dynamical core by adopting a mixed-precision computing strategy. Guided by an application of the iterative development principle, we identify the coded equation terms that are precision insensitive and modify them from double to single precision. The results show that most precision-sensitive terms are predominantly linked to pressure gradient and gravity terms, while most precision-insensitive terms are advective terms. Without using more computing resources, computational time can be saved, and the physical performance of the model is largely kept. In the standard computational test, the reference runtime of the model's dry hydrostatic core, dry nonhydrostatic core, and the tracer transport module is reduced by 24 %, 27 %, and 44 %, respectively. A series of idealized tests, real-world weather and climate modelling tests, was performed to assess the optimized model performance qualitatively and quantitatively. In particular, in the long-term coarse-resolution climate simulation, the precision-induced sensitivity can manifest at the large scale, while in the kilometre-scale weather forecast simulation, the model's sensitivity to the precision level is mainly limited to small-scale features, and the wall-clock time is reduced by 25.5 % from the double- to mixed-precision full-model simulations.

A mixed finite‐element, finite‐volume, semi‐implicit discretisation for atmospheric dynamics: Spherical geometry

AbstractOur previously described reformulation of the Met Office's dynamical core for weather and climate prediction is extended to spherical domains using a cubed‐sphere mesh. We update the semi‐implicit mixed finite‐element formulation to be suitable for spherical domains. In particular, the finite‐volume transport scheme is extended to take account of non‐uniform, non‐orthogonal meshes and uses an advective‐then‐flux formulation so that increment from the transport scheme is linear in the divergence. The resulting model is then applied to a standard set of dry dynamical core tests and compared with the existing semi‐implicit semi‐Lagrangian dynamical core currently used in the Met Office's operational model.

Soil moisture and probe characteristics affect core integrity and soil test results

AbstractProper soil sampling is critical for accurate fertilizer recommendations. Samples collected in extremely wet or dry conditions may compromise the integrity of the sample and influence analytical results. We evaluated the effects of six soil moistures, two sampling depths (0–10 and 0–15 cm), and two soil probes on soil core uniformity and soil test results. Moisture treatments encompassed a range from dry (11.2%–18.5% moisture) to saturated conditions in Captina, Dewitt, Calhoun, and Calloway silt loam soils. Core depth and dry core weight were measured in all soils, and pH and Mehlich‐3 extractable P, K, S, and Zn were assessed for Calhoun and Calloway soils. Soil moisture, probe, or their interaction influenced core depth and weight, while chemical properties were significantly affected only by soil moisture. Sampling very dry or saturated soils compromised the collection of uniform cores mainly for the 0‐ to 15‐cm depth. Soil pH tended to increase with increasing moisture, but the mean values fluctuated only ±0.3 units. Across soils and depths, extractable S consistently decreased by 16%–48% as soil moisture at sampling time increased. Phosphorus was affected by soil moisture for 0–15 cm samples in both soils but showed no clear pattern. Soil moisture at the time of sampling affected soil test K for both soils and sample depths with individual cores varying up to 47 mg kg−1 (i.e., 59–106 mg kg−1). Greater soil test P and K variability occurred for very dry and wet conditions, which often prohibit collecting samples to the proper depth and could impact fertilizer rate recommendations.

Dynamic modeling of minimum mass of pore-gas for triggering landslide in stable gentle soil slope

This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes. A stable gentle soil slope model is constructed with a dry cement powder core, a saturated clay middle layer, and a dry sand upper layer. The test injects H2O2 solution into the cement core to produce new pore-gas. The model test includes three identical H2O2 injections. The small mass of generated oxygen gas (0.07% of slope soil mass and landslide body) from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide. Meanwhile, despite the first injection causing leak paths in the clay layer, the generated small mass of gas from the second and third injections can further trigger the landslide. A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated. The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H2O2 solution in cement powder. The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07% of the landslide body. Furthermore, the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis.

Exploring the general chemistry of the core and ocean of Enceladus

Measurements made by the Cassini spacecraft instruments were able to reveal the composition of the geysers of the Saturn moon, Enceladus, among which salts (sodium chloride, sodium bicarbonate and/ or sodium carbonate) and traces of silica could be the result of hydrothermal processes from the interaction of an inner liquid ocean with the core of Enceladus.The chemistry of the ocean should be closely connected to the chemistry of the core. Even though. the actual composition of the core is unknown, Enceladus has been characterised as a moon with a silicate core and different authors have estimated the properties of the ocean.A core with a silicate composition alone, does not necessarily justify most of the observed species of the plume. Given the many uncertainties, in the current work, we study the possible chemistry of the core and the ocean in the context of a four-layered Enceladus (dry core, hydrated core, ocean and crust) with three different compositional scenarios for the core: primordial (represented by an ordinary chondrite), composite (represented by a carbonaceous chondrite with an igneous inclusion) and non primordial (epresented by a given peridotite). The scenarios comprise a set of minerals that interact with a primordial ocean (either pure or enriched water) at a given temperature and pressure, producing a series of secondary minerals and compounds, some of them, coincident with the chemical species observed in the geysers. Specifically, we make a chemical speciation for each proposed compositional scenario with the software PhreeqC, however our analysis is limited to the study of interactions that reach a given equilibrium. In particular, output values like the potential of hydrogen of the ocean or the saturation indices of mineral products may give us hints about the chemistry of the ocean and the core. We find that, based on the species observed in the plume, the actual composition of the core (and the ocean as well) poses a somewhat wide range of possible compositional scenarios and each of our proposed scenarios and their products justify, to some extent, the observations of the plume.

Fabrication of carbon nanotube epoxy prepreg towards lightweight structural composites

Despite improvements in carbon nanotube fiber tenacities, their shear strength continues to limit their performance in composite applications. Shear strength can be improved through resin penetration into the nanotube fiber hierarchical microstructure to enhance internal interfaces. In this work, a manufacturing process uses an ionic liquid and epoxy to simultaneously stretch and infiltrate nanotube roving resulting in a nanotube-epoxy-ionic liquid prepreg. The ionic liquid also serves as a latent curing agent/hardener for the prepreg. After curing, the resulting composite fiber has comparable tenacity and specific modulus to fibers made without epoxy but with improved shear properties. The dry core shear failure mode typically observed in CNT fibers was eliminated and the apparent interfacial shear strength was improved by over an order of magnitude.

The Role of Climatological State in Supporting US Heat Waves Through Rossby Waves Packets

AbstractWhile heat waves are local extreme weather events, a slowly propagating planetary‐scale Rossby wave pattern is statistically correlated to the occurrence of heat waves in the US. However, whether this correlation indicates that such planetary wave patterns physically cause the enhanced statistics of local heat waves is debatable. In this work, we hypothesize that the atmospheric climatological state controls the slowly propagating wave pattern, setting up a conducive large‐scale environment for local US heat waves. We implement an idealized dry dynamic core model with an iterative approach to simulate the realistic North American summer climatological state. As the idealized atmospheric model can generate similar zonal wavenumber five planetary wave patterns propagating throughout North America, significantly more heat waves are generated, and the statistics of heat waves become consistent with those estimated in reanalysis products. The slowly propagating Rossby wave packets with a timescale of 20–30 days may serve as a new source of intraseasonal predictability in the midlatitudes.

Optimized Design Method of Dry Type Air Core Reactor Based on Multi-Physical Field Coupling

A 3D simulation model of dry-type air core reactors is established through the multi-physical-field coupling method based on an electromagnetic-temperature-structural field, and the electromagnetic distribution characteristics, temperature, and structural deformation of the reactor are analyzed. The inductance, temperature rise, structural deformation, and amount of metal conductors of the reactor are the optimization parameters. Initially, the sample data was obtained through the orthogonal test method and multi-physical-field coupling simulation; then, the VIKOR (Vise Kriterijumski Optimizacioni Racun) method was used to equalize and control the electromagnetism, temperature rise, structural deformation, and metal conductor consumption of the reactor. Finally, multi-physical-field coupling technique is used to verify the correctness of the method. The results show that the inductance deviation of the optimized reactor is 4.51%, the highest temperature and the maximum deformation of the encapsulation coil are reduced by 13.5% and 0.52%, and the metal conductor mass of the coil increases by 7.57%, which meet the design requirements.

Modelling and validation of dry and saturated velocities in carbonates from Saudi Arabia – Part II

Ultrasonic compressional (P-wave) and shear (S-wave) velocity data, obtained from a set of 35 dry and water-saturated (carbonate) core samples, were presented as a first part to this study, in a separate paper by Bakhorji and Schmitt (2022). These carbonate samples were obtained from a prominent reservoir in Saudi Arabia.In this follow-up paper, the velocity measurements, obtained from these 35 core samples, were utilized to, firstly, predict and validate four appropriate rock physics models and to, secondly, derive empirical relationships relating the P- and S-wave velocities to the porosity and calcite content of the samples (over the effective pressure range from 5 MPa to 25 MPa). The derived empirical relationships were validated against the wireline P- and S-wave velocities assuming insitu reservoir pressure conditions. The empirical models predicted the P- and S-wave velocities accurately over the reservoir interval of interest. The shear strengthening / weakening effect, or the saturation effect on the shear moduli, was also modelled and is discussed further.The comparisons of the Biot, Gassmann, Mavko-Jizba-Biot (MJ-Biot) and Mavko-Jizba-Gassmann (MJ-Gassmann) model predictions, with the measured water-saturated P- and S-wave velocities, show that the squirt mechanism was not applicable for our samples. The Gassmann model consistently over-predicts the water-saturated S-wave velocities at low pressure, but closely fits the measured velocities at high pressures, whereas Biot over-predicts the water-saturated velocities in most of the studied samples. We conclude that Biot global-flow is most likely to be the principle dispersion mechanism in these samples.

Remote Influences of ENSO and IOD on the Interannual Variability of the West Antarctic Sea Ice

AbstractWest Antarctica exhibits a pronounced sea ice variability in interannual timescale, and 20%–30% of the total variance can be explained by the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) during austral spring. The sea ice variation is primarily linked with anomalous atmospheric circulation in the Amundsen‐Bellingshausen Sea (ABS) that modulates poleward atmospheric temperature advection and radiative forcing. With a co‐varying relationship between ENSO and IOD, isolating their remote impacts on Antarctica has been limited in observations. An idealized experiment using the atmospheric model with a dry dynamical core suggests that the anticyclonic circulation anomaly in the ABS is primarily contributed by the ENSO in the Pacific Ocean, while the contribution of the IOD in the Indian Ocean is only one‐third large. This study implies that atmospheric teleconnection through the southern Pacific Ocean is crucial for understanding the West Antarctic sea ice concentration variability.

A Global–Regional-Unified Atmospheric Dynamical Core on the Yin–Yang Grid

Abstract A global–regional-unified nonhydrostatic dynamical core was constructed on the Yin–Yang grid using a semi-implicit semi-Lagrangian solver. Arbitrary coordinate rotation was possible for both global and limited-area models with a multilevel nesting capability. Significant flexibility is available when configuring the model’s horizontal mesh using coordinate rotation. The performance of the dynamical core was assessed using a series of numerical tests in Cartesian and spherical coordinates. The results illustrate the reasonable ability of the piecewise rational method to manage sharp gradient advection and the capability of the dry dynamical core to simulate fine structures in target systems in the Cartesian and spherical configurations. An average convergence rate of 2.43 was confirmed for the dry dynamical core in the balanced flow test. The nested grid improved the fine structure simulation of the baroclinic wave development without affecting wave propagation. The propagating speed of the vortex remained unchanged in the nested grid in the colliding modons test, although the vorticity amplitude decayed more slowly than that in the coarse grid. Proper development of topographic waves was achieved for both large- and small-scale mountains with a clear damping effect in association with the off-center semi-implicit average. A deepened trough in the nesting region, in comparison with that in the parent grid, was simulated in a topographic Rossby wave test. The implementation of coordinate rotation and grid nesting improved the numerical performance when managing atmospheric dynamical problems at relatively low cost.

Using Neural Networks to Learn the Jet Stream Forced Response from Natural Variability

Abstract Two distinct features of anthropogenic climate change, warming in the tropical upper troposphere and warming at the Arctic surface, have competing effects on the midlatitude jet stream’s latitudinal position, often referred to as a “tug-of-war.” Studies that investigate the jet’s response to these thermal forcings show that it is sensitive to model type, season, initial atmospheric conditions, and the shape and magnitude of the forcing. Much of this past work focuses on studying a simulation’s response to external manipulation. In contrast, we explore the potential to train a convolutional neural network (CNN) on internal variability alone and then use it to examine possible nonlinear responses of the jet to tropospheric thermal forcing that more closely resemble anthropogenic climate change. Our approach leverages the idea behind the fluctuation–dissipation theorem, which relates the internal variability of a system to its forced response but so far has been only used to quantify linear responses. We train a CNN on data from a long control run of the CESM dry dynamical core and show that it is able to skillfully predict the nonlinear response of the jet to sustained external forcing. The trained CNN provides a quick method for exploring the jet stream sensitivity to a wide range of tropospheric temperature tendencies and, considering that this method can likely be applied to any model with a long control run, could be useful for early-stage experiment design.

Analytical solution and parameter estimation for heat of wetting and vapor adsorption during spontaneous imbibition in tuff

An analytical expression is derived for the thermal response observed during spontaneous imbibition of water into a dry core of zeolitic tuff. Sample tortuosity, thermal conductivity, and thermal source strength are estimated from fitting an analytical solution to temperature observations during a single laboratory test. The closed-form analytical solution is derived using Green's functions for heat conduction in the limit of “slow” water movement; that is, when advection of thermal energy with the wetting front is negligible. The solution has four free fitting parameters and is efficient for parameter estimation. Laboratory imbibition data used to constrain the model include a time series of the mass of water imbibed, visual location of the wetting front through time, and temperature time series at six locations. The thermal front reached the end of the core hours before the visible wetting front. Thus, the predominant form of heating during imbibition in this zeolitic tuff is due to vapor adsorption in dry zeolitic rock ahead of the wetting front. The separation of the wetting front and thermal front in this zeolitic tuff is significant, compared to wetting front behavior of most materials reported in the literature. This work is the first interpretation of a thermal imbibition response to estimate transport (tortuosity) and thermal properties (including thermal conductivity) from a single laboratory test.

Temperature field analysis of dry iron core reactor

The hot spot temperature of a dry-type iron core reactor is important for its pre-design and optimal design. To precisely study the hot spot temperature and temperature distribution law of dry iron core reactor, this paper firstly studied the loss of reactor, including coil loss and core loss, and obtained the calculation method of reactor loss. Then, the normal working environment of the dry core reactor is analyzed, and the temperature field simulation is carried out for a three-phase dry core reactor with an inductance value of 11.561 mH and capacity of 10 kV, and the hot spot temperature and temperature distribution law of this reactor are obtained and analyzed through reasonable material setting and heat dissipation method setting. Finally, the accuracy and validity of the simulation results are verified by the actual temperature rise experimental data. The research results provide a theoretical basis for structure optimization and online monitoring of the dry core reactor.

Impact of CaSO4-rich soil on Miocene surface preservation and Quaternary sinuous to meandering channel forms in the hyperarid Atacama Desert

The Atacama Desert is the driest and oldest desert on Earth. Despite the abundance evidence for long-term landscape stability, there are subtle signs of localised fluvial erosion and deposition since the onset of hyperaridity in the rock record. In the dry core of the Atacama Desert, pluvial episodes allowed antecedent drainage to incise into uplifting fault scarps, which in turn generated sinuous to meandering channels. Incision of ancient alluvial fan surfaces occurred during intermittent fluvial periods, albeit without signs of surface erosion. Fluvial incision during predominantly hyperarid climate periods is evident from these channels in unconsolidated alluvium. The absence of dense vegetation to provide bank stability and strength led us to investigate the potential role of regionally ubiquitous CaSO4-rich surface cover. This has enabled the preservation of Miocene surfaces and we hypothesize that it provided the required bank stability by adding strength to the upper decimetre to meter of incised alluvium to allow high sinuosity of stream channels to form during pluvial episodes in the Quaternary.