Irregular Channels Research Articles

Effects of current rate on electrically exploding aluminum wires in argon gas

The electrically exploding wires (EEWs) method is a low-cost, high-efficiency method for nanoparticle preparation. The current parameter is a determining factor of EEWs’ characteristics and nanoparticles’ size distribution. This paper systematically investigates the effects of the current rate on the resistive stage and diffusion process of EEWs in argon gas. The electrical measurement indicated that EEWs tend to transform from current-pause mode to direct-breakdown mode as the current rate increases. Deposited energy increases with the current rate approximately linearly due to improved power and overheating limits. Spatial inhomogeneities include residual cores, irregular discharge channels, local hot spots, and stratification structures. The residual core is formed because of the rivalry between the vaporized part and the condensed wire core. Increasing the current rate suppresses the above-mentioned inhomogeneities and accelerates diffusion.

A 3D Janus stainless steel mesh bed with high efficiency and flux for on-demand oil-in-water and water-in-oil emulsion separation

Janus materials with asymmetric wettability have attracted wide attention in oil/water separation due to the ability to remove water or oil on demand. In this work, a Janus stainless steel mesh (SSM) combining superhydrophilicity and high hydrophobicity was prepared through in-situ growth of polydopamine (PDA) and SiO2, phase interface deposition of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFOTS) on one side and floating deposition of polydopamine/polyethyleneimine (PDA/PEI) on the other side. Relying on the unidirectional water transportation ability, the Janus SSM could efficiently separate light/heavy oil/water mixtures on demand with a water removal rate of 7000 L·m−2·h−1 and an oil removal rate of 46,000 L·m−2·h−1. Based on this, a three-dimensional (3D) Janus SSM bed was designed by controllable assembling single piece of Janus SSM and 20 pieces of superhydrophilic SSM with in situ grown PDA@SiO2 nanoparticles (PDA@SiO2 SSM). The 3D Janus SSM bed showed excellent emulsion separation ability due to its long irregular permeation channels to make emulsified liquid droplets continuously collide, agglomerate and demulsificate. For oil-in-water emulsion, the separation efficiency could reach 99.31% and the flux was higher than 2864 L·m−2·h−1. For water-in-oil emulsion, the separation efficiency was over 99.68% and the permeation flux could reach 7072 L·m−2·h−1. With these excellent performances, the 3D Janus SSM bed was believed to be able to bring important contributions to the modern industrial oil/water separation process.

A pore-resolved interface tracking algorithm for simulating multiphase flow in arbitrarily structured porous media

We present an interface tracking algorithm that incorporates essential pore-scale invasion mechanisms for simulating multiphase flow in porous media in capillary dominated regime. The algorithm allows the capture of the actual shape of porous medium with complex geometrical features, including both convex and concave particles or irregular channels. It also incorporates the sharp edge pinning effect such that pinning of menisci at corners can be naturally taken into account. We firstly conduct simulations under imbibition and drainage conditions in a single junction micro-model and in disordered porous media for validation. It is shown that the invasion mechanisms at pore scale are accurately captured, and the macroscopic invasion morphology in porous media are reproduced. A series of simulations for fluid displacement processes are carried out across a wide range of intrinsic contact angles in a two-dimensional representation of a Berea sandstone. The transition between stable displacement and capillary fingering is characterized using displacement efficiency, fractal dimension, and fluid–fluid interfacial length. This work deepens the understanding of fluid–fluid displacement processes in porous media. Furthermore, the presented interface tracking algorithm offers a highly efficient tool for further exploration of effects of wettability, geometry, and topology on multiphase flow in realistic porous materials.

Vascular Tumors in Two Argentine Horned Frogs (Ceratophrys ornata)

Two vascular tumors in two Argentine horned frogs (Ceratophrys ornata) are described. Case 1 involved a 7-year-1-month-old Argentine horned frog that had a splenic mass with a sanguineous coelomic effusion. Histologically, the splenic parenchyma was effaced by a poorly-demarcated, invasive mass, consisting of spindle cells with marked nuclear atypia forming irregular blood vessel channels containing blood. Case 2 involved a pedunculated facial mass located at the upper right lip of an over-8-month-old Argentine horned frog. Histologically, the well-demarcated, poorly cellular mass consisted of sparse proliferation of spindle cells forming irregular slits with prominent edema. Immunohistochemically, the neoplastic cells of both cases were positive for anti-CD31 antibody. The diagnoses were hemangiosarcoma in case 1 and lymphangioma in case 2. To the best of the authors’ knowledge, this is the first description of neoplastic diseases in captive Argentine horned frogs.

A visco-inertial formulation for capillarity in irregular channels and tubes

We propose a novel formulation of capillarity, which geometrically extends the Bosanquet equation to irregular geometries, taking the effect of inertia and the dynamic contact angle into account. The governing equation is an integrodifferential equation that is solved numerically and compared with computer simulations, experimental data, and other cases available in the literature. The numerical examples investigated in this work show that contrary to flat channels and tubes, inertial effects decay much slower in corrugated channels and tubes due to the walls' geometrical fluctuations. We also draw the paramount conclusion that the true solution for Jurin's height in irregular capillaries is path-dependent and highly sensitive to the initial conditions, and no single static-equilibrium solution can necessarily be attributed to the eventual position of the meniscus. Resulting from the non-linear dynamics, the multiple equilibria in the presence of gravity for irregular capillaries can only be analyzed if the effect of inertia is considered, which has largely been neglected in the literature thus far.

Biomimetic 3D Membranes with MXene Heterostructures for Superior Solar Steam Generation, Water Treatment, and Electricity Generation

2D MXene materials have shown great potential in photothermal conversion, especially for solar steam generation. However, the obvious light losses at the liquid−solid interfaces still limit its broad applications, thereby resulting in a poor light absorption ability. To this end, a facile and general approach is designed for the construction of nanoflower MXene@MoS2 with excellent photothermal conversion ability via one‐step hydrothermal process. Thanks to the multireflective and synergestic effects between MXene and MoS2, the hierarchical MXene@MoS2 heterostructure exhibits broadband light absorption and improved photothermal conversion capacity (69 °C after 10 min solar illumination). Furthermore, inspired by the water vapor process in multiple channels of trees, an ultrathin MXene@MoS2‐based nanofibrous membrane is assembled via directional electrospinning technology. Compared with traditional irregular channels, the controllable and tree‐inspired 3D structure shows competitive advantages in solar absorption and water transport. Thus, the as‐prepared self‐floating membrane presents durable hydrophobicity (contact angle [CA] = 125°) and a high evaporation rate of 1.39 kg/(m2h) (91% efficiency) under 1 sun, which is higher than reported. This 3D MXene‐based device also shows promising electrical generation, solar‐driven sewage, and desalination treatments (99% desalination efficiency). Such high‐performance self‐floating photothermal membranes with multifunctionalities might provide an effective strategy for solving the global problems of freshwater shortage.

Filiform projections of the vestibular mucosa: What’s your diagnosis?

29-year-old recently married woman was reffered by her gynecologist to our dermatology department for suspected vulvar condyloma acuminatum. She had no history of any extramarital sexual contacts and her partner was free of any clinical features of genital HPV infections. She was anxious about the origin of her lesions and the risk of her husband’s contamination. She reported burning sensation, irritation and vulvar pain. On clinical examination soft digitate mucous colored papules with a smooth surface were noted at the vulvar vestibule. These papillomatous projections were pearly, uniformly arranged and had separate bases (Fig. 1). Dermatoscopy demonstrated regular and linear pinkish projections arranged in a symmetric distribution. Irregular linear vascular channels were observed (Fig. 2). Figure 1: Clinical aspect: multiple skin-colored filiform and soft projections. Figure 2: Dermatoscopy showing regular and linear pinkish projections arranged in a symmetric distribution. WHAT’S YOUR DIAGNOSIS? ANSWER: Vestibular Papillomatosis Vestibular papillomatosis (VP) is a normal variant of the female genital mucosa [1,2]. It is first described in 1981 by Altemeyer and named pseudocondylomata of the vulva [3]. VP is frequently misdiagnosed as condyloma acuminatum and presents a source of anxiety in patients, aggressive investigations and inappropriate treatment [2]. This entity is most often asymptomatic, but it can be accompanied, as our case, by a feeling of burning, pain or dyspareunia. To avoid the misdiagnosis of VP as genital warts, Moyal-Barranco et al. had proposed five clinical parameters [4]. Unlike condyloma acuminatum, VP is formed by regular, soft and pink-colored papillae arising from a separate base. It is also characterized by the lack of circumscribed whitening on 5% acetic acid application. Dermoscopy can help to differentiate these two conditions by allowing a better identification of these clinical parameters. Linear vessels may sometimes be observed in the transparent core of the finger-like projections [5]. On the other hand, dermoscopy of condyloma acuminatum shows irregular whitish projections with tapering end that arise from a common base and comprise conglomerate vessel. Based on these clinical criteria and the dermoscopic aspect, biopsies will be unnecessary to confirm the diagnosis of VP.

Optimizing Fe-Based Metal-Organic Frameworks through Ligand Conformation Regulation for Efficient Dye Adsorption and C2 H2 /CO2 Separation.

Regulating the structure of metal-organic frameworks (MOFs) by adjusting the ligands reasonably is expected to enhance the interaction of MOFs on special molecules/ions, which has significant application value for the selective adsorption of guest molecules. Herein, two tricarboxylic ligands H3 L-Cl and H3 L-NH2 were designed and synthesized based on the ligand H3 TTCA by replacing part of the benzene rings with C=C bonds and modifying the chlorine and amino groups on the 4-position of the benzene ring. Two 3D Fe-MOFs (UPC-60-Cl and UPC-60-NH2 ) with the new topology types were constructed. As the C=C bonds of the ligands have flexible torsion angles, UPC-60-Cl features three types of irregular 2D channels, while UPC-60-NH2 has a cage with two types of windows on the surface. The synergistic effect of unique channels and modification of functional groups endows UPC-60-Cl and UPC-60-NH2 with high adsorption capacity for organic dyes. Compound UPC-60-Cl shows high adsorption capacity for CV (147.2 mg g-1 ), RHB (100.3 mg g-1 ), and MO (220.9 mg g-1 ), whereas UPC-60-NH2 exhibits selective adsorption of MO (158.7 mg g-1 ). Meanwhile, based on the diverse pore structure and modification of active sites, UPC-60-Cl and UPC-60-NH2 show the selective separation of equimolar C2 H2 /CO2 . Therefore, reasonable regulation of organic ligands plays a significant role in guiding the structure diversification and performance improvement of MOFs.

APPLICATION OF GEORGIAN NATURAL ANALCIME FOR PRODUCTION OF ION EXCHANGERS

Analcime is a fairly widespread zeolite in the territory of Georgia and other countries, but its practical application is limited due to the peculiarities of its compact structure with small pores and irregular channels. This work describes a method developed by us for hydrothermal recrystallization of analcime into a widely used ion exchanger of the LTA type in the form of micrometric crystals or nanosized crystals, depending on the synthesis conditions. Silver-, copper-and zinc-containing analcimes and synthetic LTA zeolites with bacteriostatic activity were obtained by ion exchange. It has been shown that the highest bacteriostatic activity is possessed by a silver-containing synthetic zeolite, and analcimes enriched with relatively cheap copper and zinc exhibit activity sufficient for practical use in water treatment, paper production and other applications.

Representative activation energy and solar biomemtic pump with blood flow having variable thermo physical properties

Peristaltic phenomena is expanded broadly in biomedical applications in recent years. Solar energy system is very beneficial to humanity and these are progressively being restyled to get advantage from fluids. Most solar collector's schemes include inflexible geometries which may be parabolic, cylindrical, flat-plate or tube like categories. Current progresses in biomimetic have acknowledged that irregular channels, tubes, pipes, etc. may be valuable for energy systems. Inspired by these characteristics, the present work presents an original model for fashioning a biomimetic heat and mass transference peristaltic solar fluid based pump. The thermo-physical physical properties (mass diffusivity, viscosity and conductivity) are assumed to be changeable due to heat and mass diffusions. The uniqueness of the current paper is the consolidation of peristaltic motion, variable fluid properties, activation energy and blood flow in a planetary thrust system. Heat is transferred through the walls and due to vertical flow buoyancy effects are considered. Study of heat/mass transfer are accomplished by assuming the effects of non-constant thermal conductivity, mass diffusivity, viscosity and activation energy. To implement solar filling conditions, an emitting radiation unstable model is also used. In order to create an activation energy, a chemical reaction is taken at rational rate, the temperature of the system is assumed to be so high that it creates number of molecules in the form of energy known as activation energy. Additionally, the noticeable characteristics of pumping and trapping phenomena are addressed concisely. For High values of Weissenberg number, the pumping and augmented pumping regions have same behavior. Pre-exponential factor and chemical reaction causes increase in concentration distribution.

Análise morfométrica de incisivos inferiores através de microtomografia computadorizada

Estudos sobre anatomia dental e morfologia interna do sistema de canais radiculares são importantes para otimizar a terapia endodôntica. O conhecimento das variações no número de canais, número de raízes, dimensões horizontais e largura de canais aumentam a compreensão e domínio da anatomia para o clínico. O presente estudo tem por objetivo descrever a análise morfométrica de incisivos inferiores através de microtomografia computadorizada. Um total de 47 (n=47) incisivos inferiores permanentes tiveram sua anatomia interna avaliada através de microtomografia computadorizada tridimensional com parâmetros de aquisição, reconstrução e análise padronizados. Quando avaliado a presença de dois canais radiculares ao nível do terço médio e apical, foram encontrado um total de 3 elementos (6,4%). O formato de canal mais prevalente foi de canais ovais longos (47,7%), seguido de canais achatados (34,1%). Não foram encontrados canais irregulares. Pelo presente estudo foi possível concluir que o formato de canal mais prevalente em incisivos inferiores permanentes é o oval longo, não sendo encontrado canais irregulares.

Impact of particles tracking model of nanofluid on forced convection heat transfer within a wavy horizontal channel

Development of modern heat exchangers or solar collectors is related to the analysis of working fluid flow and heat transfer within different channels. The energy transport enhancement can be reached by including nanofluids as working media and irregular channels to intensify the heat removal. The present research is devoted to computational analysis of nanosuspension forced convection in a horizontal wavy channel under the impact of heating from the upper wavy surface. The single-phase nanofluid approach with experimentally-based correlations for viscosity and thermal conductivity holds implemented for an investigation in combination with Newton's second law for the description of the motion of the nanoparticle within the channel. The formulated boundary-value problem has been worked out by the finite element technique. Rules of Reynolds number, number of channel waviness, and dimensionless time on nanoliquid flow, energy transport and nanoparticles motion within the channel as well as average parameters. It has occurred that a rise from Reynolds number characterizes a narrowing of the fluid tube within the channel with an improvement of the average velocity and average Nusselt number. Augmentation of the channel waviness number results in an increment of the average particles velocity and average temperature.

Primary Hepatic Vascular Neoplasm in a Houston Toad (Anaxyrus houstonensis)

An 11-year-old captive, female Houston toad (Anaxyrus houstonensis) became lethargic and reluctant to move. This toad had been administered human chorionic gonadotropin (HCG) and luteinizing hormone-releasing hormone (LHRH) annually as part of a hormone-assisted captive propagation programme for 8 years. Due to poor prognosis, euthanasia was elected. At necropsy, the liver was moderately enlarged, diffusely dark red and had a nodular superficial appearance. Microscopically, the hepatic nodules consisted of poorly demarcated, non-encapsulated, paucicellular infiltrative neoplastic growths. These consisted of spindle cells, similar to sinusoidal endothelial cells, that formed irregular blood-filled vascular channels resembling sinusoids separated by thin bands of collagen and reticulin fibres. Neoplastic cells dissected through and replaced hepatic cords and bile ducts. Based on the cytohistomorphological features and analogy with vascular neoplasms in other vertebrates, a diagnosis of low-grade angiosarcoma was made. To the best of our knowledge, this is the first record of primary hepatic vascular neoplasia in an amphibian. It is not known if the long-term administration of HCG and LHRH had any oncogenic role in this animal. Vascular neoplasia should be included in the differential diagnosis of hepatomegaly and non-specific lethargy and health decline in amphibian species.

Adsorption properties of modified eggshell on phosphorus in water

Modified eggshell adsorbent was prepared with 5% potassium permanganate solution to adsorb phosphorus in simulated wastewater. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to clarify their phosphorus removal mechanisms. Isothermal and kinetic equations were fitted to explain the mechanism of phosphorus adsorption. The results showed that the optimum conditions were as follows: phosphorus concentration of 5 mg·L-1, wastewater pH of 2, adsorbent dosage of 3.5 g, adsorption time of 350 min, phosphorus adsorption rate of modified eggshell was 90.81%, and the experimental results were relatively stable. According to the characterization, the eggshell adsorbent has good crystallinity, irregular surface structure and abundant pore channels，and the main functional groups on the surface are hydroxyl (-OH) and C-H groups, which enhanced the adsorption effect.

Stuck in transit: asylum-seeking habitus and onward migration aspirations of Sri Lankan Tamil asylum-seekers in Bangkok

ABSTRACT Asylum-seekers nowadays undertake multiple journeys before reaching a country of resettlement. In Southeast Asia, several countries are playing important roles as transit locations. This paper focuses on Thailand, which serves as a major transit point for Sri Lankan Tamil asylum-seekers who hope to move to resettlement countries through irregular channels. Drawing on in-depth interviews and ethnographic observations from 2018 to 2019, this paper examines the Sri Lankan Tamil asylum-seekers’ migration experiences in Bangkok, and how they plan their onward migration and utilise connection networks. Moving beyond traditional pull-push approach that standardises reasons to flee, this research uses asylum-seeking habitus as a conceptual lens to explore the interactive process between structure (economic and cultural) and asylum-seekers, and individual/communal interpretations of such structural environment that trigger onward migration aspirations of asylum-seekers in a transit country. In Bangkok, because lived experiences do not meet personal and/or familial expectations, insecurity prevails following news from others in their networks, which then triggers onward migratory disposition among Sri Lankan Tamil asylum-seekers. Asylum-seeking habitus as a conceptual lens provides a useful approach in assisting us in understanding asylum-seekers’ vision of autonomy by investigating their changing perceptions of security at different stages of the journey.

Machine learning application identifies novel gene signatures from transcriptomic data of spontaneous canine hemangiosarcoma.

Angiosarcomas are soft-tissue sarcomas that form malignant vascular tissues. Angiosarcomas are very rare, and due to their aggressive behavior and high metastatic propensity, they have poor clinical outcomes. Hemangiosarcomas commonly occur in domestic dogs, and share pathological and clinical features with human angiosarcomas. Typical pathognomonic features of this tumor are irregular vascular channels that are filled with blood and are lined by a mixture of malignant and nonmalignant endothelial cells. The current gold standard is the histological diagnosis of angiosarcoma; however, microscopic evaluation may be complicated, particularly when tumor cells are undetectable due to the presence of excessive amounts of nontumor cells or when tissue specimens have insufficient tumor content. In this study, we implemented machine learning applications from next-generation transcriptomic data of canine hemangiosarcoma tumor samples (n = 76) and nonmalignant tissues (n = 10) to evaluate their training performance for diagnostic utility. The 10-fold cross-validation test and multiple feature selection methods were applied. We found that extra trees and random forest learning models were the best classifiers for hemangiosarcoma in our testing datasets. We also identified novel gene signatures using the mutual information and Monte Carlo feature selection method. The extra trees model revealed high classification accuracy for hemangiosarcoma in validation sets. We demonstrate that high-throughput sequencing data of canine hemangiosarcoma are trainable for machine learning applications. Furthermore, our approach enables us to identify novel gene signatures as reliable determinants of hemangiosarcoma, providing significant insights into the development of potential applications for this vascular malignancy.

In situ growth of two-dimensional ZIF-L nanoflakes on ceramic membrane for efficient removal of iodine

Radioactive pollutants are in places a serious environmental pollution problem. By virtue of their structural diversity and tunability, two-dimensional (2D) zeolitic imidazolate frameworks-L (ZIF-L) have shown a promising ability for pollutant removal by adsorption. For the first time, we propose a 2D ZIF-L assembled on and in a microporous ceramic membrane for efficient removal of iodine via seed-assisted in situ growth. It is challenging to customize inner pore channels of ceramic membrane due to its irregular structure. This work provides new insights into the crystallographic growth of ZIF-L on the inner irregular pore channels and a homogenous ZIF-L layer on porous silicon carbide (SiC) membranes. The resulting hybrid membrane contains highly loaded ZIF-L nanoflakes on the surface and pore channels of the SiC membrane. These multilayers structure and ZIF-L@SiC synergistic features provide more active sites and improve the mass transfer of molecular iodine dissolved in cyclohexane, thereby enhancing removal efficiency. The removal efficiency of iodine using the hierarchically nanostructured ZIF-L@SiC hybrid membrane is near 100% and 96% at a flux of 9.37 × 103 L m−2 h−1 with iodine/cyclohexane concentrations of 5 mg L−1 and 50 mg L−1, respectively. This porous adsorption membrane, with excellent separation and adsorption capacities for iodine, opens a new way for radionuclide adsorption.

Institutional Engagement Practices as Barriers to Public Health Capacity in Climate Change Policy Discourse: Lessons from the Canadian Province of Ontario.

Public health engagement in the communication, discussion, and development of climate change policies is essential for climate change policy decisions and discourse. This study examines how the existing governance approaches impact, enable, or constrain the inclusion, participation, and deliberation of public health stakeholders in the climate change policy discourse. Using the case study of the Canadian Province of Ontario, we conducted semi-structured, key informant interviews of public health (11) and non-public health (13) participants engaged in climate change policies in the province. The study results reveal that engagement and partnerships on climate change policies occurred within and across public health and non-public health organizations in Ontario. These engagements impacted public health’s roles, decisions, mandate, and capacities beyond the climate change discourse; enabled access to funds, expertise, and new stakeholders; built relationships for future engagements; supported knowledge sharing, generation, and creation; and advanced public health interests in political platforms and decision making. However, public health’s participation and deliberation were constrained by a fragmented sectoral approach, a lack of holistic inter-organizational structures and process, political and bureaucratic influences, irregular and unestablished communication channels for public health integration, and identities and culture focused on functions, mandates, biased ideologies, and a lack of clear commitment to engage public health. We conclude by providing practical approaches for integrating public health into climate change discourse and policymaking processes and advancing public health partnerships and collaborative opportunities.

Toward the Highly Ordered Lamellar Hybrid Membrane for Molecular Sieving by One-Pot Self-Assembly of Hybrid Hyperbranched Polymer

Ordered lamellar hybrid membranes are of great interest, due to their application as functional materials, including molecular sieving, biosensors, optical devices, and drug, as well as gene delive...

An Event-Based Inventory Approach in Landslide Hazard Assessment: The Case of the Skolis Mountain, Northwest Peloponnese, Greece

Assessment of landslide hazard across mountains is imperative for public safety. Pre- and post-earthquake landslide mapping envisage that landslides show significant size changes during earthquake activity. One of the purposes of earthquake-induced landslide investigation is to determine the landslide state and geometry and draw conclusions on their mobility. This study was based on remote sensing data that covered 72 years, and focused on the west slopes of the Skolis Mountains, in the northwest Peloponnese. On 8 June 2008, during the strong Movri Mountain earthquake (Mw = 6.4), we mapped the extremely abundant landslide occurrence. Historical seismicity and remote sensing data indicate that the Skolis Mountain west slope is repeatedly affected by landslides. The impact of the earthquakes was based on the estimation of Arias intensity in the study area. We recognized that 89 landslides developed over the last 72 years. These landslides increased their width (W), called herein as inflation or their length (L), termed as enlargement. Length and width changes were used to describe their aspect ratio (L/W). Based on the aspect ratio, the 89 landslides were classified into three types: I, J, and Δ. Taluses, developed at the base of the slope and belonging to the J- and Δ-landslide types, are supplied by narrow or irregular channels. During the earthquakes, the landslide channels migrated upward and downward, outlining the mobility of the earthquake-induced landslides. Landslide mobility was defined by the reach angle. The reach angle is the arctangent of the landslide’s height to length ratio. Furthermore, we analyzed the present slope stability across the Skolis Mountain by using the landslide density (LD), landslide area percentage (LAP), and landslide frequency (LF). All these parameters were used to evaluate the spatial and temporal landslide distribution and evolution with the earthquake activity. These results can be considered as a powerful tool for earthquake-induced landslide disaster mitigation