Entire Medium Research Articles

First Report of Fusarium concentricum Causing Leaf Blight, Shoot Blight, Flower and Fruit Rot on Kadsura coccinea in China.

Kadsura coccinea (Lem.) A. C. Smith is a traditional medicinal plant grown in south China. Lignans and terpenoids extracted from the root, fruit and stem were found to have anti-proliferative, anti-HIV, anti-hepatitis, anti-oxidant, neuroprotective, and other pharmacological attributes for treating rheumatoid arthritis and gastroenteric et al. disorders (Yang et al., 2020). However, little is known about the biotic disorders of this evergreen climbing shrub. In surveys carried out in a 15- hectare -orchard located 23°59'55''N, 113°55'13''E, all K. coccinea plants were observed exhibiting an array of symptoms including leaf blight, shoot blight, flower rot and fruit rot from May to July of 2023, with disease incidences of 17% , 18%, 16% and 28%, respectively. A greyish -brown blight appeared predominantly on the leaf margins or tips. Light to dark brown lesions on the shoots, flower calyxes and fruits were slightly sunken, irregularly shaped, and watery, usually with white aerial mycelium. For pathogen isolation, infected tissues were cut into fragments of about 5 mm in diameter, surface sterilized with 75% ethanol for 15 s and 1% NaClO for 2 min, and then rinsed three times with sterilized distilled water. Filter paper-dried tissues were placed onto potato dextrose agar (PDA) and incubated at 28°C for 5 days. Seventy-one morphologically similar colonies were produced from 100 tissue fragments, with other tissues lacking colonies or with different colonies. Genomic DNA of 10 randomly selected isolates were extracted from 5-day-old pure cultures. Molecular characterization of the 10 subcultured strains was analyzed by sequencing three regions i.e. translation elongation factor 1-alpha (TEF-1), beta-tublin (TUB), and RNA polymerase Ⅱ second largest subunit (RPB2), amplified using primers EF1/EF2 (O'Donnell et al., 1998), T1/T22 (O'Donnell and Cigelnik 1997), and RPB2-5f2/RPB2-7cr (Liu et al. 1999). Maximum likelihood and Bayesian Inference analysis based on the dataset of the combined three sequences by MEGA 11.0 showed that nine strains were consistently identified as F. concentricum. The three sequences (OR632200, OR632199, and OR754282) of a representative strain (SGXF1) shared 99.42%, 99.62%, and 99.80% identity with those of the type strain CBS450. 97. The colonies were white to pale buff with serrated edges and sparse aerial mycelium that initially formed a loose, white cottony texture of 5-10 mm in height. After 7 d's culture at 26°C in an incubator with a photic door, dense and abundant fluffy reddish-white aerial mycelium covered the entire PDA medium of 9 cm-diameter, with alternating pale orange and reddish-grey concentric rings at center with diffusible pigments. Catenate microconidia were obovoid to fusoid-shaped, mostly 0-septate, with a flattened base, (10.98 ± 0.83) x (3.41 ± 0.15) μm (n=20), and were produced on both mono-and polyphialides, whereas macroconidia were curved and long, with a slightly beaked apical cell and a basal cell, mainly 3- to 5-septate, and (33.80 ± 0.81) x (4.31 ± 0.12) μm (n=20) in size. These morphological characteristics further indicates it to be F. concentritum (Nirenberg and O'Donnell, 1998; Xiao et al., 2023). To determine pathogenicity, three 1-y-old seedlings were wound inoculated by conidial suspension (1 × 106 conidia/mL) on different tissues and incubated at 25°C in a greenhouse with 10 replications. At 2 d after inoculation (DAI), the treated flowers gradually turned from fresh red and green to black at calyxes, with the black area then gradually expanding. At 6 DAI, part of the flowers turned black, accompanied by white mycelium and yellowish powdery spots. Similarly, leaves, stems, and fruits turned from green to dark brown at infection sites within 7 DAI. Black to brown, uneven necrotic areas, and reddish spots were observed under a dissecting microscope, with white mycelium attached at 6 DAI. The symptoms observed in lab were similar to those observed in the field, whereas three control plants remained asymptomatic. Fungal colonies identical to initial isolations were recovered from artificially infected tissues and confirmed to be F. concentricum again, thereby completing Koch's postulates. This report is the first to document F. concentricum causing disease on K. coccinea. Appropriate measures will be developed based on this study to protect this economically important plant in the field.

Enzyme-Free In-Situ Electrochemical Measurement Using a Porous Membrane Electrode for Glucose Transport into Cell Spheroids.

Microphysiological systems have attracted attention because of their use in drug screening. However, it is challenging to measure cell functions in real time using a device. In this study, we developed a cell culture device using a porous membrane electrode for in situ electrochemical glucose measurements for cell analysis. First, a porous membrane electrode was fabricated and electrochemically evaluated for enzyme-free glucose measurement. Subsequently, the glucose uptake of MCF-7 spheroids was evaluated using living spheroids, fixed spheroids, supernatants, and glucose transporter inhibitor-treated spheroids. Conventionally, the direct optical measurement of glucose uptake requires fluorescence-labeled glucose derivatives. In addition, the glucose uptake can be evaluated by measuring the glucose concentration in the medium by optical or electrochemical measurements. However, glucose needs to be consumed in the entire cell culture medium, which needs a long culture time. In contrast, our system can measure glucose in approximately 5 min without any labels because of in situ electrochemical measurements. This system can be used for in situ measurements in in vitro cell culture systems, including organ-on-a-chip for drug screening.

A lightweight, flexible, and polarization-insensitive microwave absorbing honeycomb core using conductive losses in printed periodic pattern

This study proposes a method for providing electromagnetic function by arranging patterns three-dimensionally on honeycomb partition walls. A conductive paste is thinly printed to fabricate a resistance component. To increase the current path induced by the incident electromagnetic waves, a rectangular pattern with an aspect ratio is used to further generate electromagnetic losses. Rectangular patterns are arranged alternately to ensure the homogeneity of the entire honeycomb medium. The proposed honeycomb achieved excellent absorption performance in the C, X, and Ku bands, regardless of the polarization. Simulations were used to show that the microwave-absorption performance of a honeycomb with a three-dimensional pattern could be estimated analytically. The obtained results were compared with those of other studies. The proposed honeycomb was effective in reducing the broadband monostatic radar cross section when applied to the leading edge of a wing box.

Medium inhomogeneities modulate emerging spiral waves

We study the spatiotemporal dynamics of spiral waves in a lattice of chemically coupled memristive FitzHugh–Nagumo neurons. We also introduce local and global functional inhomogeneities by means of variations in nodal action potentials that are distributed in different ways. We find that, in the presence of globally distributed random inhomogeneity, increasing the maximum threshold for excitability generates neurons with reduced depolarization capacity. Although such a setup makes the entire medium less excitable and thus challenges the robustness of emerging spiral waves, highly excitable neurons can compensate for the less excitable ones, thereby nonetheless preserving the spiral wave pattern. However, this compensatory mechanism has limitations, which can ultimately lead to the elimination of spiral waves under specific conditions. When inhomogeneities are local, two different scenarios are possible. If the distribution is random, the spiral tip cannot penetrate the inhomogeneous region but remains resilient against it. The tip is consistently anchored to the inhomogeneity, meandering around its boundary. As the inhomogeneity size increases, the curvature of the spiral tip and the propagation speed of the circular wavefronts decrease. If the distribution is uniform, inhomogeneities are analogous to semi-conducting barriers, thus permitting the spiral rotor to penetrate while sacrificing the strength of its wavefronts.

Groundwater Vulnerability Mapping Using the Susceptibility Index (SI) Method and Tritium Isotopes: A Case Study of the Gharb Aquifer in Northwestern Morocco

The Gharb aquifer plays a critical role as a source of drinking water and irrigation in Morocco. However, rapid economic growth and increased use of chemical fertilizers have led to groundwater pollution and land degradation. To address this issue, a vulnerability assessment was conducted using the Susceptibility Index (SI) method. Five parameters including depth to groundwater, effective recharge, slope, soil type, and land use/land cover were considered to evaluate groundwater vulnerability. The vulnerability assessment revealed index values ranging from 31 to 160. The study area was categorized into three zones of relative vulnerability (low, moderate, and high). Spatial analysis demonstrated significant spatial heterogeneity, with moderate vulnerability observed in areas characterized by shallow groundwater and composed primarily of sandstones in the northwest and southwest regions. In the entire study area, the low, medium, and high vulnerability zones covered 3%, 70%, and 26% (101 km2, 2725 km2, and 986 km2), respectively. Furthermore, Tritium isotope analysis and nitrate content were selected and applied as pollution markers to confirm and validate the obtained vulnerability map. The Tritium (3H) content in groundwater reveals a correlation with an R2 value of 0.86 with the degree of vulnerability, while the nitrate concentration in the aquifer’s groundwater showed a correlation with an R2 value of 0.55.

A Method for Rapid Polyethyleneimine-Based Purification of Bacteriophage-Expressed Proteins from Diluted Crude Lysates, Exemplified by Thermostable TP-84 Depolymerase.

Purification of bacteriophage-expressed proteins poses methodological difficulties associated with the need to process entire culture medium volume upon bacteriophage-induced bacterial cell lysis. We have used novel capsule glycosylase-depolymerase (TP84_26 GD) from bacteriophage TP-84, infecting thermophilic Geobacillus stearothermophilus bacteria, as a representative enzyme to develop a method for rapid concentration and purification of the enzyme present in diluted crude host cell lysate. A novel variant of the polyethyleneimine (PEI)-based purification method was devised that offers a fast and effective approach for handling PEI-facilitated purification of bacteriophage-expressed native proteins. Due to the very basic nature of PEI, the method is suitable for proteins interacting with nucleic acids or acidic proteins, where either mixed PEI-DNA or RNA-protein complexes or PEI-acidic protein complexes are reversibly precipitated. (i) The method is of general use, applicable with minor modifications to a variety of bacteriophage cell lysates and proteins. (ii) In the example application, TP84_26 GD was highly purified (over 50%) in a single PEI step; subsequent chromatography yielded a homogeneous enzyme. (iii) The enzyme's properties were examined, revealing the presence of three distinct forms of the TP84_26 GD. These forms included soluble, unbound proteins found in host cell lysate, as well as an integrated form within the TP-84 virion.

Antifungal Activity of Endophytic Bacteria Isolated from Miana Plants (Coleus scutellarioides (L.) Benth.) against Candida albicans

Highlights: 1.Due to the adverse effects associated with current antifungal drugs, research on traditional medicine is necessary to explore other options for candidiasis treatment.2.Following the findings of this study, it is recommended to conduct further research by incorporating Coleus scuttellarioides filtrate into the growth medium, since this may improve bacterial growth by producing optimal secondary metabolites. Abstract Candida albicans is the most common organism responsible for both mucosal and systemic infections, accounting for approximately 70% of fungal infections worldwide. Miana, scientifically known as Coleus scuttellarioides (L.) Benth., is recognized for its use in traditional medicinal practices. Miana plants contain endophytic bacteria that possess the ability to produce secondary metabolites with potential antifungal agents. The objective of this study was to assess the antifungal activity of nine endophytic bacteria isolates derived from Coleus scuttellarioides against Candida albicans. This study was laboratory-based qualitative experimental research that applied the Kirby-Bauer diffusion method and several modifications. The Candida albicans specimens were spread throughout the entire potato dextrose agar medium. Afterwards, paper discs that had been soaked in a liquid culture of endophytic bacterial isolates were carefully placed on the surface of the medium. The complete setup was then incubated for 1–2 days. The potential antifungal activity of endophytic bacteria was assessed by observing the emergence of a clear zone surrounding their growth, which would indicate inhibition. An additional observation was performed in the follow-up test, involving the use of Sabouraud dextrose agar medium to confirm the initial test result. The results from the inhibitory test revealed that none of the bacterial isolates exhibited any inhibition zone. Conversely, ketoconazole as the positive control showed an inhibition zone with an average diameter of 28.5 mm. In conclusion, endophytic bacterial isolates obtained from Coleus scuttellarioides have no discernible antifungal properties against Candida albicans. This study implies that ketoconazole remains effective in treating infections caused by Candida albicans.

Dynamic phase transition induced by active molecules in a supercooled liquid.

The purpose of this work is to use active particles to investigate the effect of facilitation on supercooled liquids. To this end we examine the behavior of a model supercooled liquid that is doped with a mixture of active particles and slowed particles. To simulate the facilitation mechanism, the activated particles are subjected to a force that follows the mobility of their most mobile neighboring molecule, while the slowed particles experience a friction force. Upon activation, we observe a fluidization of the entire medium along with a significant increase in dynamic heterogeneity. This effect is reminiscent of the fluidization observed experimentally when introducing molecular motors into soft materials. Interestingly, when the characteristic time τ_{μ}, used to define the mobility in the facilitation mechanism, matches the physical time t^{*} that characterizes the spontaneous cooperativity of the material, we observe a phase transition accompanied by structural aggregation of the active molecules. This transition is characterized by a sharp increase in fluidization and dynamic heterogeneity.

The Comparison of Seven Models to Simulate the Transport and Deposition of Polydisperse Particles under Favorable Conditions in a Saturated Medium

Polydisperse particles are ubiquitous in both the natural and engineered environment, and the precise prediction of the transport and capture of polydisperse particles in a saturated medium is crucial. Several efforts (Yao model, RT model, TE model, MPFJ model, NG model, MHJ model, and MMS model) were developed to obtain accurate correlation equations for the particle capture probability (single-collector removal efficiency), but the applicability of the existing models to the entire porous medium and the retention characteristic of the polydisperse particles are still unclear. In this study, sand column experiments were undertaken to investigate the transport and capture processes of the polydisperse particles in the saturated medium. The mass density was employed to quantize the effects of particle polydispersity and incorporated into the depth-dependent deposition rate. The experimental results showed that the polydisperse particles formed a hyper-exponential retention profile even under favorable conditions (no repulsion). The excellent agreement between the results obtained from the MMS model and the experimentally observed results of the breakthrough curves (BTCs), as well as the retention profiles demonstrated the validation of the MMS model, as the correlation coefficient and the standard average relative error were 0.99 and 0.005, respectively. The hyper-exponential retention profile is caused by the uneven capture of the polydisperse particles by the porous medium. This study highlights the influences of particle polydispersity on particle transport and capture in a saturated porous medium.

Synthetic Aperture Ultrasound Imaging through Adaptive Integrated Transmitting-Receiving Beamformer.

Synthetic aperture (SA) technique is very attractive for ultrafast ultrasound imaging, as the entire medium can be insonified by a single emission. It also permits applying the dynamic focusing as well as adaptive beamforming both in transmission and reception, which results in an enhanced image. In this paper, we firstly show that the problem of designing the transmit and receive beamformers in SA structure can be formulated as a problem of designing a one-way beamformer on a virtual array with a lateral response equal to that of the two-way beamformer on SA. It is also demonstrated that the length of the virtual aperture is increased to the sum of the transmit aperture length and the receive one, which can result in an enhanced resolution. Moreover, a better estimation of the covariance matrix can be obtained which can be utilized for applying adaptive minimum variance (MV) beamforming method on the virtual array, and consequently the resolution and contrast properties would be enhanced. The performance of the new method is compared with other existing MV-based methods and is quantified by some metrics such as the full width at half maximum (FWHM) and generalized contrast to noise ratio (GCNR). Our validations on simulations and experimental data have shown that the new method is capable of obtaining higher GCNR values while retaining or decreasing FWHM values almost all the time. Moreover, for the same subarray length for estimating the covariance matrices, the computational burden of the new method is significantly lower than those of the existing rival methods.

Direct seismic modeling: day surface topography and shallow subsurface anisotropy

Introduction. The article is devoted to one of the problems in the development of oil and gas fields - the construction of correct geological models of the subsurface space. Researchers from various scientific groups around the world have proposed various ways to improve the accuracy of the computer simulations used in this process. The purpose of this study is to assess the degree of influence of the day surface relief and the anisotropy of the upper part of the geological section on the recorded seismic signal using a realistic model of the Orenburg field as an example.Materials and methods. A seismogeological model describing the Lower Permian interval of the Orenburg geological section is considered. According to well data, the elastic properties of geological formations were estimated: density and propagation velocities of longitudinal and transverse waves. There is a high contrast of P-wave velocities estimated from sonic logs. The reservoir in this model is confined to the lower layers. It is composed of sulfate-carbonate media, uniform in density and acoustic properties. Using the grid-characteristic method, zero-offset synthetic seismograms were calculated. The choice of structural curvilinear computational grids made it possible to correctly consider the relief of the day surface.Research results. In this work, two different models were compared. The first model included the anisotropy of the upper part of the section and the topography of the day surface. In the second model, the upper boundary of the computational domain was flat, and the entire medium was considered within the framework of an isotropic linear elastic model. The analysis of synthetic seismograms showed that the anisotropy inherent in this model does not significantly affect the recorded seismic wave field. However, considering the relief of the day surface significantly shifts the times of arrival of reflected waves.Discussion and Conclusion. The algorithm presented in the paper can be used to verify the field data processing graph, since the assessment of the anisotropy of the medium is a standard step in building a velocity model. The presented approach can be extended to 3D models of realistic dimensions.

Modeling the viscosity and rotation on a generalized micropolar thermoelasticity with two-temperature under five theories

ABSTRACT The current study establishes the generalized micropolar thermo-visco-elasticity model in an isotropic elastic material with two temperatures. At a uniform angular velocity, the entire elastic medium is rotated. The description is implemented under five generalized thermoelasticity theories: Lord-Shulman (L-S) with one relaxation time, Green-Lindsay (G-L) with two relaxation times, Green-Naghdi theory (G-N II) without energy dissipation, and Tzou theory with dual phase lags (DPL), much like the coupled theory. We used the normal mode analysis to obtain the specific articulations for the considering factors. Additionally, some specific cases are discussed with regard to the problem. Numerical findings are collected and displayed graphically for the variables under consideration. Different theories (L-S, G-L, G-N II, and DPL), rotation, viscosity, and two temperatures were used to predict the results.

Quantitative Analysis of Photothermal Therapy of Tumor Tissue Using Various Gold Nanoparticle Injection Schemes.

Photothermal therapy is a new chemotherapy technique using photothermal effects, a phenomenon in which light energy is converted into thermal energy. Since the treatment technique is performed without surgical incision, it does not cause bleeding and patients are expected to make rapid recoveries, which are significant advantages. In this study, photothermal therapy with direct injection of gold nanoparticles into tumor tissue was simulated through numerical modeling. The treatment effect resulting from changing the intensity of the irradiated laser, volume fraction of the injected gold nanoparticles, and number of gold nanoparticle injections was quantitatively evaluated. The discrete dipole approximation method was applied to calculate the optical properties of the entire medium, and the Monte Carlo method was applied to identify the absorption and scattering behavior of lasers in tissue. In addition, by confirming the temperature distribution of the entire medium through the calculated light absorption distribution, the treatment effect of photothermal therapy was evaluated, and the optimal treatment conditions were suggested. This is expected to accelerate the popularization of photothermal therapy in the future.

Thermal Radiation and Mass Transfer Analysis in an Inclined Channel Flow of a Clear Viscous Fluid and H2O/EG-Based Nanofluids through a Porous Medium

Nanofluid flow has acquired various interesting dimensions with the advent of several novel approaches to studying thermophysical properties. The present work focuses on a comparative study of clear viscous and nanofluid (EG−Al2O3, EG−Zr, H2O−Al2O3, H2O−Zr) flow in a two-phase inclined channel saturated with a porous medium in the presence of thermal radiation, species diffusion, and viscous and Darcy dissipation effects. The controlling equations of the flow model were solved analytically using the regular perturbation technique. The graphical solutions are used to examine the impacts of physical parameters on the most significant flow features. Surface graphs with distinct entrenched parameters represent heat transfer rates and shear stresses on plates. The resulting heat transfer was enhanced by raising the thermal and solute buoyancy strengths, while thermal radiation had the opposite outcome. This enhancement of temperature was maximum for water–zirconium and minimum for ethylene glycol–aluminum oxide nanofluid. The concentration of the entire fluid medium is reduced by decreased mass diffusivity. The enhancement of temperature and velocity is found to be maximum in the nanofluid region and clear fluid region, respectively. This study is validated with previously published works to demonstrate its effectiveness.

Influence of memory-dependent derivative on generalized thermoelastic rotating porous solid via three-phase-lag model

This paper is concerned with the influence of memory-dependent heat transport law on rotating thermoelastic medium with voids via three-phase-lag. The entire pervious medium is rotating with a invariant angular haste, where the bounding airplane is subordinated to a thermal shock and is free of tractions. By employing the normal mode analysis, the exact expressions for the displacement components, stresses, temperature distribution and change in volume fraction field have been depicted graphically in the presence and the absence of gyration and memory-dependent outgrowth. The effect of the voiding is also bandied in the literature review.

Immobilization of 137Cs as a crystalline pollucite surrounded by amorphous aluminosilicate

To date, radiocesium (137Cs) has been considered stable in the form of pollucite mineralized through high-temperature heat treatment. This study presented a possibility through experimental results that the entire medium exists as amorphous aluminosilicate at a relatively low temperature, but cesium is partially and preferentially converted from a composite adsorbent into pollucite. Cesium lowers the eutectic point within the system and initiates the nucleation of pollucite prior to other elements. We confirmed that the partial mineral phase of cesium showed the same chemical stability as when the entire medium was converted to pollucite. X-ray absorption spectroscopy provided direct evidence for this phenomenon; also, the stability results of radioactive cesium shown through a series of sintering experiments supported the conclusion. This method can be applied as a method to immobilize radioactive cesium under relatively mild temperature conditions of atmospheric pressure, while eliminating the problem of diffusion due to its volatilization.

The Implications of Ultra-Faint Dwarf Galaxy Reticulum II on the Common Envelope Jets Supernova r-process Scenario

We show that the common envelope jets supernova (CEJSN) r-process scenario is compatible with very recent observationally determined properties of the stars in the ultra faint dwarf (UFD) galaxy Reticulum II that are strongly enhanced in r-process elements. These new results, like efficient mixing of the r-process elements in the Reticulum II galaxy, have some implications on the CEJSN r-process scenario for UFD galaxies. In particular, the energetic jets efficiently mix with the common envelope ejecta and then with the entire interstellar medium of Reticulum II. The compatibility that we find between the scenario and new observations suggests that the CEJSN r-process scenario supplies a non-negligible fraction of the r-process elements.

Aquifer characteristics and groundwater flow system in a typical basement complex and Gundumi formation northwest, Nigeria

Aquifer performance was tested in 280 locations of the study area to assess the hydraulic characteristics of the various aquifers, potential yield from the flowing boreholes of both hard rocks and sedimentary formation underlain Zamfara State Northwestern, Nigeria. Pumping test result were subjected to standard methods of Jacob’s and modified Theis equation for evaluation of aquifer parameters such as hydraulic conductivity (K), Transmissivity (T), Specific capacity and others. The results show that characteristic of areas underlain by crystalline rock units, especially migmatite, variably migmatized gneiss, schists and granites are characterized by thin/shallow overburden unit of usually less than 10m. In such settings the borehole depth varies from 38 to 78m while saturated thickness varies from 8 to 20m below ground level, with average yield of 44.1m3/day. Hydrogeological parameters obtained from pumping test analysis within the basement rock units revealed aquifer transmissivity (T) values which range from 0.14 to 141.23m2/day, with an average of 12.85m2/day. This implies aquifers of negligible to high potentials. The hydraulic conductivity (K) values vary from 5.0 x 10-2m/day and 8.8 x 10-1m/day with an average of 2.2 x 10-1m/day. The implication of these results is that the aquifers of the basement rock units cannot provide sufficient water for both domestic and agricultural needs of the area. However, Sixty-eight (68) analyzed borehole data set within Gundumi Formation, revealed the average discharge rate of 116.8m3/day. This formation shows the highest water discharge within the study area. The average penetration depth of 65m was achieved. The hydraulic conductivity of this aquifer revealed average value of 5.7 × 10-1m/day. This implies high permeability of aquifer system, which is typical of sedimentary formation of this nature. Transmissivity (T) revealed an average value of 38.89m2/day, which indicate high rate of water flow through the entire aquifer medium of this formation. The geospatial analysis of yield from the wells indicate excellent groundwater potential around the western part of the study area.

Cavitation‐Associated Water Evaporation From Porous Media Through In Situ NMR Characterization

AbstractEvaporation of water from porous media is essential for a large variety of applications, whereas the opacity of porous matrix imposes considerable challenges in unveiling complicated phase‐change phenomena. Air invasion was previously reported as the major desaturation mechanism, while cavitation in porous media is not well studied. Herein we characterize the transient distribution and evaporation of water in homogeneous tight porous media with nondestructive nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). By monitoring the amplitude change of NMR transverse relaxation time T2, we investigate the dynamical pore filling status and water content during evaporation. Interestingly, we find that the T2 spectrum shifts immediately after the evaporation starts, indicating the emptying of big pores from the entire medium. Disconnected void clusters at different depths in the porous medium are also observed from MRI scanning and optical images. These observations indicate the emergence of cavitation across the entire porous media along with the evaporation from open surface. Cavitation occurs when the water is stretched to metastable state by large capillary pressure from the evaporating meniscus. By studying the evaporation from hydrophilic membrane‐separated porous media, we further demonstrate the existence of cavitation‐associated evaporation. The preferential water vaporization from the bottom part can still be found from T2 spectrum analysis and optical imaging even when the water‐permeable membrane cuts off possible air invasion. Our findings confirm cavitation‐associated evaporation is one of the primary mechanisms for tight porous media, which provides valuable guidance for evaporation and moisture control.

Movement of flexible filter media under pulse-jet filter cleaning conditions

Reverse pulse-jet cleaned bag filters are widely used for the removal of fine particles from gas streams. Based on the material properties of a single fiber, the entire filter medium is modeled which shows an elastic and apparent viscous property mainly due to the restoration of the weaving pattern. Thus, for the pulse-jet cleaning, the actual transient pressure difference can be linked directly to the deflection of the filter medium. The filter medium displacement is simulated for the filtration and cleaning measures by finite element method (FEM) for a clamped filter test sample and the large-scale bag filter situation, respectively. As expected a high curvature of the filter medium coincides with a high equivalent tensile stress which in turn is a pre-curser for the probability for cake breakage.