Fluid Components Research Articles

Effect of the Aligned Magnetic Field over a Stretching Sheet through Porous Media in Casson Fluid Flow

Researchers in the thermo-fluidic field have dedicated considerable effort to exploring methods for improving heat transfer in diverse thermal systems. Among these methods, incorporating porous mediums into thermal systems stands out as particularly effective. The movement of substances through these porous materials, which encompass both fluid and solid components, can be described by either assuming that both phases are at the same temperature or that they are at different temperatures. The significance of heat and mass flux arises from their association with chemical potential and temperature gradient respectively. These connections hold value within a wide array of fields, including electrical power generation, solar power technology, chemical engineering, petrology and many more. In the present study, aligned magnetic effects have been investigated on local thermal non-equilibrium (LTNE) circumstances on steady, incompressible, laminar flow of a non-Newtonian Casson fluid across a stretching sheet in a porous medium. The LTNE conditions are implemented to generate two distinct temperature profiles for both fluid and solid phases. By choosing appropriate similarity transformations, the governing partial differential equations are transformed into ordinary differential equations for the flow parameters and are solved using numerical method Runge-Kutta-4 with shooting technique. The flow attributes are thoroughly inspected graphically in response to the influence of the developing factors. As aligned magnetic parameter and porosity parameter values increase, heat transmission improves, but velocity decreases. In the flow zone, as values of angle increases, magnetic field intensity increased. The heat flux in both fluid and solid phases decreases as the Dufour number rises. As the Soret number rises, the mass transfer rate falls.

RECAPITULATING ARTICULATING JOINT MOTION EX VIVO TO BETTER UNDERSTAND CHONDROGENIC DIFFERENTIATION

Articulating cartilage experiences a multitude of biophysical cues. Due to its primary function in distributing load with near frictionless articulation, it is clear that a major stimulus for cartilage homeostasis and regeneration is the mechanical load it experiences on a daily basis. While these effects are considered when performing in vivo studies, in vitro studies are still largely performed under static conditions. Therefore, an increasing complexity of in vitro culture models is required, with the ultimate aim to recreate the articulating joint as accurately as possible. We have for many years utilized a complex multiaxial load bioreactor capable of applying tightly regulated compression and shear loading protocols. Using this bioreactor, we have been able to demonstrate the mechanical induction of human bone marrow stromal cell (BMSC) chondrogenesis in the absence of exogenous growth factors. Building on previous bioreactor studies that demonstrated the mechanical activation of endogenous TGFβ, and subsequent chondrogenesis of human bone marrow derived MSCs, we have been further increasing the complexity of in vitro models. For example, the addition of high molecular weight hyaluronic acid, a component of synovial fluid, culture medium leads to reduced hypertrophy and increased glycosaminoglycan deposition. The ultimate aim of all of these endeavors is to identify promising materials and therapies during in vitro/ ex vivo studies, therefore reducing the numbers or candidates that are finally tested using in vivo studies. This 3R approach can improve the opportunities for success while leading to more ethically acceptable product development pathways.

Study of a small molecule gel fracturing fluid and its in situ conversion into an efficient oil displacement agent

Viscoelastic surfactants (VESs) are critical components of water-based fracturing fluids.

Microfluidic platform for the enzymatic pretreatment of human serum for the detection of the tuberculosis biomarker mannose-capped lipoarabinomannan.

Tuberculosis (TB) represents a major public health threat, with millions of new cases reported worldwide each year. A major hurdle to curtailing the spread of this disease is the need for low-cost, point-of-care (PoC) diagnostics. Mannose-capped lipoarabinomannan, a significant component of the Mycobacterium tuberculosis bacillus, has been heavily studied as a biomarker for TB, but with little success due to its complexation with endogenous components of body fluids in a manner that sterically interferes with its detection by ELISA and other immunoassays. Recent work by our group and others has shown that complexation can be disrupted with protein-denaturing protocols. By way of followup, we recently described an enzymatic digestion (Proteinase K) sample pretreatment that enables quantitative recovery of ManLAM spiked into healthy human control serum. Herein, we report on the transfer of our benchtop sample pretreatment methodology to an automated microfluidic platform. We show that this platform can be configured to: (1) carry out the pretreatment process with very little user interaction and, (2) yield recoveries for ManLAm spiked into control serum which are statistically indistinguishable from those achieved by the benchtop process. Plans to integrate this device with a portable sample reader as a possible basis for a PoC TB diagnostic system and analyze patient samples are briefly discussed.

Impact of a spherical interface on a concentrical spherical droplet

<p>In this paper, an analytical and numerical technique are examined in order to analyse the Stokes flow determination problem due to a viscous sphere droplet moving at a concentric instantaneous position inside a spherical interface separating finite and semi-infinite immiscible fluid phases. Here, when only one of the three phases of the fluid (micropolar fluid) has a microstructure, attention is focused on this case. The motion is considered when Reynolds- and capillary-numbers are low, and the droplet surface and the fluid-fluid interface have insignificant deformation. A general solution is obtained in a spherical coordinate system based on a concentric position to analyse the slow axisymmetric movement of the micropolar fluid, considering microrotation and velocity components. Boundary conditions are initially fulfilled at the fluid-fluid interface and subsequently at the droplet surface. The normalised hydrodynamic drag force applying to a moving viscous droplet appears to be a function of the droplet-to-interface radius ratio, which increases monotonically and becomes unbounded when the droplet surface touches the fluid-fluid interface. The numerical outcomes of the normalised drag force acting on the viscous droplet are derived for different values of the parameters, and are presented in a tabular and graphical framework. A comparison was made between our numerical outcomes for the drag force and the pertinent data for the special cases found in the literature.</p>

Enhanced Design Automation for Hydraulic Manifolds Produced Using Additive Manufacturing

Complex, highly functional components such as hydraulic manifolds can be produced using metal additive manufacturing (AM). The design process is a major challenge in the development of AM components that exploit this potential. Since traditional CAD systems are not made to efficiently create highly complex designs, new approaches to the design process are required. Design Automation (DA) and Knowledge-Based Engineering (KBE) are approaches that can be used to create designs and implement design changes faster and improve functionality. For the application of fluid components, KBE design workflows were developed which enable the automated generation of AM manifolds.However, these workflows have some limitations that need to be improved to provide a flexible design tool that enables users to automatically create geometries that meet all requirements. This paper shows how the workflows have been improved by introducing two new features. First, the object-oriented input format presents a new approach to how the information of a hydraulic circuit diagram can be processed to start the workflows. This is done through a component library that contains a selection of flow components providing all information and geometries of one component, a 3D layout assembly to orient the relevant components in space, and a connectivity matrix that defines the connection through flow channels for the manifold. Second, the bending radius constraint allows users to define a radius that the centerline of a flow channel should not undergo along the whole path. The new features are presented in detail in this paper. Further, the advantages are shown and compared to the previously published workflows in a case study. This work lays the foundation for future work that has the aim to fully automate the design process by only taking a hydraulic circuit diagram as an input and providing all required manufacturing files as an output.

Differential cell analysis in ovine bronchoalveolar lavage fluid: Effect of different sampling methods and seasons.

Bronchoalveolar lavage (BAL) is a method for collecting the cellular and fluid components of the airway surface in the lungs. The assessment of differential cell profiles is potentially valuable in the diagnosis of pulmonary diseases, but there is no information about the normal BAL profiles in the Gezel breed. This study aimed to characterize the normal cryptologic findings of BAL with Gezel sheep. Twenty healthy sheep (15 females: 5 males, bodyweight: 55-65 kg) were sedated with xylazine (0.02-0.04 mg/kg IV). Two methods; the transtracheal bronchoalveolar lavage technique and the bronchoscopic bronchoalveolar lavage using a scope were evaluated. Sampling was performed in the summer and winter seasons. Normal value (Mean ± SEM) for total cell, macrophage, lymphocyte, neutrophil, epithelial, and bronchial cells in BAL sampled in summer were (343.75 ± 30.23), ) 24.50 ± 2.62), (2.81 ± 0.51), (1.43 ± 0.88), and (3.12 ± 0.32), respectively. The normal values for the total cell, macrophage, lymphocyte, neutrophil, epithelial, and bronchial cells in BAL sampled in winter were (355.55 ± 37.67), (59.11 ± 4.30), (21.33 ± 3.10), (3.88 ± 1.07), (8.88 ± 3.78), and (6.33 ± 1.44), respectively. No significant change in the percentage of neutrophils was detected between seasons, although the percentages of bronchial and epithelial cells in winter were significantly high (p < 0.05). Except for the mentioned cases, neither the total cell number nor the percentage differential cell populations of BAL changed significantly (p < 0.05) in different sampling methods and seasons. Normal BAL profiles in the Gezel breed were determined and could be used in result interpretations. Also, both sampling methods can be used without significantly affecting the results.

A review of the Zn-Pb deposits in Sichuan-Yunnan-Guizhou metallogenic region with emphasis on the enrichment mechanism of Ge, Ga, and In

The low-medium temperature Zn-Pb deposits in the Sichuan-Yunnan-Guizhou (SYG) metallogenic region contain not only Pb and Zn but also abundant critical metals such as Ge, Ga, and In. The majority of previous studies focus on the genesis of Pb and Zn metals, and the research on Ge, Ga and In in the SYG region has become a topic in recent years due to economic importance of these metals. In this review, the distribution, occurrence, and enrichment mechanism of Ge, Ga, and In in Zn-Pb deposits in the SYG region is summarized. Sphalerite is the main host mineral of Ge, Ga, and In, with contents of up to ∼1300 ppm, ∼600 ppm, and ∼1191 ppm, respectively. Pyrite from the Fule Zn-Pb deposit is also rich in Ge (up to 340 ppm), which may be due to involvement of magmatic components in the ore-forming fluids. Germanium, Ga, and In mainly appear in the form of isomorphism in sphalerite. Independent minerals of Ge such as ruizhongite (Ag2□)Pb3Ge2S8), are only found in the Wusihe Zn-Pb deposit. Copper is the main coupling ions for substitution of Ge, Ga, and In in sphalerite. However, the positive correlation of Ge with Pb, Mn and Ag in the sphalerite of Huodehong, Shaojiwan, Shanshulin, and Qingshan Zn-Pb deposits may indicate other means of substitution or existence of nanometer Ge minerals with similar composition to the ruizhongite. The substitution mechanisms of Ge and Ga vary with layers in the zoned sphalerite from the Nayongzhi Zn-Pb deposit, possibly indicating that physical or chemical variations in fluids will affect the substitution ways of Ge and Ga in sphalerite.The growth direction and crystal structure of ZnS also exert control over the contents of Ge, Ga, and In. The enrichment degree of Ge, Ga, and In changes between (110) and (111) crystal planes, and the wurtzite structure is beneficial to the infiltration of large ions (Ge, Ga, and In). Compared to sphalerite with euhedral texture, colloform sphalerite is conducive to the enrichment of Ge. For zoned sphalerite such as the rhythmic banding and the conventional zone, the former lacks zoning of Ge, Ga and In but the latter shows elemental zonation and Ge is enriched in the black domains. The correlation between the contents of Ge, Ga, and possible In in sphalerite and Pb or Zn isotopes of sulfides indicates the significant contribution of basement rocks for the enrichment of these metals. During the mineralization process, Ge tends to be enriched in dark or early sphalerite, including the Daliangzi, Tianbaoshan, Huize, Nayongzhi, Fule, Fuli, Wusihe, and Maoping deposits, which may be due to the variations in temperature or fluid evolution. The opposite variation trend of Ge and Ga with sphalerite color or stage in the Daliangzi, Nayongzhi, Maoping, Shaojiwan, and Wusihe Zn-Pb deposits indicates that Ge and Ga may behave differently during precipitation of sphalerite.

Raman spectroscopic characterization of the CO2-N2 gaseous system at 24–300°C and 2–40 MPa and applications

ABSTRACT CO2 and N2 are important gas components of deep-sourced geological fluids. To establish a quantitative method for the study of these fluids, we used a high-pressure optical cell, a heating–cooling stage, and a laser Raman spectrometer to examine pure CO2 and N2 gases and nine CO2-N2 gaseous mixtures at 24–300°C and 2–40 MPa. The results show that the CO2 Fermi diad split and the peak area ratios of the ν 1 band of N2 to the upper band of CO2 are considered to be the best for determining pressure and composition, respectively. The quantitative Raman analysis method developed in this study for the determination of the C N2/C CO2 molar ratio was verified by measuring those in synthetic N2-CO2-H2O fluid inclusions. The developed method has also been applied to the analysis of natural fluid inclusions in quartz from Donghai for the determination of both the C N2/C CO2 molar ratio and pressure.

Shoshonitic pluton and an associated base-metal deposit in the Tarom–Hashtjin metallogenic zone, NW Iran: implication for tectono-magmatic evolution and metallogenic considerations

Petrological, geochemical and zircon U–Pb and Hf isotope studies were carried out on the Hajseyran pluton, along the Tarom–Hashtjin metallogenic zone, as part of the Alborz–Azerbaijan magmatic belt, which is located in the central part of the Alpine–Himalayan orogenic belt. The Hajseyran pluton, which is made up of syenite, monzonite, quartz-monzonite and granite, yields a zircon U–Pb age of 39.20 ± 0.56 Ma (for a quartz-monzonite sample) with shoshonitic features. Enrichment in large ion lithophile elements, depletion in high-field-strength elements and negative anomalies of Nb, Ta and Ti in Chomalou samples suggest a subduction-related arc magmatic setting. The Chomalou epithermal Pb–Zn–Cu deposit occurs close to the Hajseyran pluton with the quartz–base metal sulfide veins predominantly hosted by Eocene volcanic rocks. The ore-forming processes include chalcopyrite and sphalerite–galena formation, with the latter the major mineralisation in this region. Microthermometric results from the liquid–vapour fluid-inclusion assemblages show that the homogenisation temperatures in the first-stage quartz range from 230 to 310 °C, in the sphalerite and second-stage quartz from 161 to 293 °C and in the late-stage quartz from 175 to 262 °C. The salinities of fluids decrease from early-stage quartz to late-stage quartz. The calculated stable isotope values of ore–fluid components (δ18Owater = +3.28‰ to −3.68‰; δ34SH2S = +5.5‰ to +7.8‰) show that magmatic fluids have played a significant role during mineralisation. The Chomalou deposit is interpreted as a volcanic-hosted intermediate-sulfidation type of epithermal mineralisation formed through shallow-level emplacement of the Hajseyran pluton, which formed via partial melting of phlogopite–amphibole-bearing sub-continental lithospheric mantle. The Neotethyan slab roll-back and concomitant asthenospheric upwelling led to the decompression melting of metasomatised sub-continental lithospheric mantle and the formation of several K-rich plutons and associated epithermal deposits in the Alborz–Azerbaijan magmatic belt.

A New Workflow for Assessment of Fluid Components and Pore Volumes From 2D NMR Measurements in Formations With Complex Mineralogy and Pore Structure

It is challenging to reliably identify fluid components and estimate their saturations in formations with complex lithology, complex pore structure, or varying wettability conditions. Common practices for assessing fluid saturations rely on the interpretation of resistivity measurements. These techniques require model calibration, which is time consuming/expensive and can only differentiate conductive and nonconductive fluids. Interpretation of 2D NMR maps provides a viable alternative for identifying fluid components and fluid volumes. However, conventional techniques for the interpretation of 2D NMR rely on cutoffs in the T1-T2 or D-T2 maps. The application of cutoffs is prone to inaccuracies when fluid-component relaxation responses overlap. To address these shortcomings, we introduce a new workflow for identifying/tracking fluid components and estimating their volumes from the interpretation of 2D NMR measurements. We developed a workflow that approximates 2D NMR maps with a superposition of 2D Gaussian distributions. The algorithm automatically determines the optimum number of Gaussian distributions and their corresponding properties (i.e., amplitudes, variances, and means). Next, a clustering technique is implemented to the dataspace containing the Gaussian distribution parameters obtained for the entire logged interval. Each Gaussian is assigned to a cluster corresponding to different pore/fluid components. We then calculate the volumes under the Gaussian distributions corresponding to each cluster at each depth. The volumes associated with each cluster translate directly into the pore volumes corresponding to the different fluid components (e.g., heavy/light hydrocarbon, bound/free water) at each depth. A highlighted contribution of this work is that, in contrast to the alternative petrophysical interpretation techniques for fluid characterization, the introduced workflow does not require calibration efforts, user-defined cutoffs, or proprietary data sets. Furthermore, approximating 2D NMR data with a superposition of Gaussian distributions improves the accuracy of estimated pore volumes of fluid components with overlapping NMR responses. The clustering using the Gaussian distribution parameters as inputs enables depth tracking of different fluid components without making use of user-defined 2D cutoffs. Finally, the multidimensional nature of the introduced clustering provides the unique capability of identifying different fluid components with 2D NMR response located in the same range of coordinates in a T1-T2 map. We successfully verified the reliability and robustness of the new workflow for enhancing petrophysical interpretation in two organic-rich mudrock formations with complex mineralogy and pore structure.

The role of elastic instability on the self-assembly of particle chains in simple shear flow

Flow-induced self-assembly (FISA) is the phenomena of particle chaining in viscoelastic fluids while experiencing shear flow. FISA has a large number of applications across many fields including materials science, food processing, and biomedical engineering. Nonetheless, this phenomena is currently not fully understood and little has been done in literature so far to investigate the possible effects of the shear-induced elastic instability. In this work, a bespoke cone and plate shear cell is used to provide new insights on the FISA dynamics. In particular, we have fine-tuned the applied shear rates to investigate the chaining phenomenon of micrometer-sized spherical particles suspended into a viscoelastic fluid characterized by a distinct onset of elastic instability. This has allowed us to reveal three phenomena never reported in literature before, i.e.,: (I) the onset of the elastic instability is strongly correlated with an enhancement of FISA; (II) particle chains break apart when a constant shear is applied for “sufficiently” long-time (i.e., much longer than the fluids' longest relaxation time). This latter point correlates well with the outcomes of parallel superposition shear measurements, which (III) reveal a fading of the elastic component of the suspending fluid during continuous shear flows.

Reverse phase, ion exchange, HILIC and mix-mode chromatography for the determination of metformin and evogliptin in human plasma and pharmaceutical formulations

Separation and quantification of highly polar metformin (MTF) alone or in combination with dipeptidyl peptidase-4 inhibitors, such as evogliptin (EVG), sitagliptin, saxagliptin, vildagliptin, linagliptin and teneligliptin, specifically from human plasma and pharmaceutical products is still difficult in mostly preferred ODS based RP-HPLC techniques. Since, owing to weak retention of MTF in ODS, it elutes together with the biological fluid components and drug excipients. Therefore, in this study, alternative to ODS based RP-HPLC, comparatively less known analytical techniques like strong cation exchange chromatography (SCX-3), hydrophilic interaction liquid chromatography (HILIC) and mix-mode chromatography (MMC) were comprehensively evaluated for their potentials and limitations in simultaneous quantification of newly approved EVG and MTF combination (Valera-M). In results, prolonged application of SCX-3, exhibits irreproducible and irreversible retention of MTF and EVG. While in HILIC with Cyano column, excessive acetonitrile as eluent developed the precipitation of MTF and column back pressure. Comparatively, the Acclaimed® mix-mode HILIC-1, demonstrated much promising and reproducible results for MTF and EVG separation and importantly, it can be used either reverse phase or HILIC mode. Considering the overall benefits of Acclaimed® mix-mode HILIC-1, it was used in estimation of MTF and EVG from human plasma and pharmaceutical formulations.

Reproductive Immunology and Embryo Acceptance

Pregnancy is a test of the fundamental laws of transplantation immunology - the coexistence of genetically disparate tissues without host immune rejection. Advances over recent decades show that implantation and placental development depend on an active state of maternal immune tolerance, and breakdown of tolerance is a key contributor to infertility and recurrent pregnancy loss. Tolerance in pregnancy depends on regulatory T (Treg) cells, which are critical to inhibit effector immunity, constrain inflammation, and support maternal vascular adaptations that allow placental access to maternal nutrient supply. Treg cell defects are implicated in disorders of embryo implantation and placental development, but the origins of Treg cell dysfunction are unknown. In recent studies, we have comprehensively analysed the phenotypes and transcriptional profile of peripheral blood Treg cells in individuals with early pregnancy failure (recurrent miscarriage and recurrent implantation failure). Compared to fertile women, women with early pregnancy failure have fewer total Treg cells and altered Treg cell phenotypes, accompanied by lower Treg:Th1 and Treg:Th17 ratios. RNAseq demonstrates an aberrant Treg cell gene expression profile in early pregnancy failure, with upregulation of pro-inflammatory genes including CSF2, IL4, IL17A, IL21, and IFNG. Our data indicate that Treg cell defects in women with early pregnancy failure can arise due to loss of lineage fidelity associated with impaired FOXP3 regulation. Factors including metabolic function, luteal phase progesterone, and male partner seminal fluid components are all implicated in causing Treg cell deficit. Treg cells may be a useful target for therapeutic interventions to improve uterine receptivity, but this will depend on developing diagnostic tests that are informative. Moreover, safe, and effective interventions to modulate these cells are in their infancy, and personalized approaches matched to specific diagnostic criteria will be needed.

Molecular simulation of the dynamic distribution of complex oil components in shale nanopores during CO2-EOR

Due to the high clay content of shale reservoirs, developing shale oil by water flooding is difficult. CO2 is easier to inject into formations than water, significantly increasing shale oil production by reducing the viscosity of shale oil and increasing the gas-oil ratio. Moreover, CO2 flooding can also effectively reduce emissions. However, CO2 flooding changes the formation fluid's phase behavior and composition. This causes the fluid to redistribute in the nanopore. Based on the field data, it can be seen that the changes of formation fluid components are obvious in the three stages of CO2 injection, the initial state of production and depressurization production. Therefore, this paper uses the molecular dynamics method to study the changes in adsorption layer thickness, adsorption ratio of components, interaction energy, and self-diffusion coefficient of fluids in organic and inorganic pores under these three stages. The results show that the adsorption layer thickness gradually increases during CO2 flooding. After CO2 injection, the fluid components in kerogen are significantly desorbed. The desorption of the components in the small pore size of illite, feldspar, and calcite is insignificant; the desorption of the components in the large pore size is significant, and the desorption of the components in quartz is insignificant. The interaction energy between fluid and pores decreases first and then increases during CO2 flooding, and the types of interaction energy between pores and fluids differ. The results show that CO2 injection can increase shale oil production. New ways to enhance oil recovery are needed to increase shale oil production in the later stage of depressurization production.

A hybrid WENO5IS-THINC reconstruction scheme for compressible multiphase flows

We present a hybrid reconstruction scheme for compressible multiphase flows governed by the five-equation model with surface tension and molecular viscosity. The Godunov-type method utilizes a fifth-order incremental stencil weighted essential non-oscillatory (WENO5IS) scheme to resolve flow structures in each component, while the Tangent of Hyperbola for INterface Capturing (THINC) maintains sharp fluid interfaces. Supplemented with positivity- and boundedness-preserving limiting procedures, the scheme exhibits a high level of robustness for multiphase flow problems with strong compressibility and large acoustic impedance mismatch. One- and two-dimensional benchmark cases demonstrate the efficiency and accuracy of interface-sharpening, and the high resolution capability for each fluid component. Numerical tests under extreme conditions corroborate the excellent robustness, and simulations with surface tension and viscosity also exhibit the versatility of the proposed approach.

Symmetric teleparallel cosmology with boundary corrections

We investigate the geometrodynamical effects of introducing the boundary term in symmetric teleparallel gravity. Specifically, we consider a homogeneous and isotropic universe in fQ,B, where Q is the non-metricity scalar, and B is the boundary term that relates the non-metricity and Ricci scalars. For the connection in the coincidence gauge, we find that the field equations are of fourth-order, and the fluid components introduced by the boundary are attributed to a scalar field. In the coincidence gauge, the cosmological field equations are equivalent to those of teleparallelism with a boundary term. Nevertheless, for the connection defined in the non-coincidence gauge, the geometrodynamical fluid consists of three scalar fields. We focus on the special case of fQ,B=Q+FB theory, and we determine a new analytic cosmological solution that can explain the late-time acceleration of the universe and provide a geometric mechanism for the unification of dark energy with dark matter.

Coalescence and mixing dynamics of droplets in acoustic levitation by selective colour imaging and measurement

Acoustic levitation is well-suited to ‘lab-on-a-drop’ contactless chemical analysis of droplets. Rapid mixing is of fundamental importance in lab-on-a-drop platforms and many other applications involving droplet manipulation. Small droplets, however, have low Reynolds numbers; thus, mixing via turbulence is not possible. Inducing surface oscillation is effective in this regard, however, the relationship between internal flow and mixing dynamics of droplets remains unclear. In this study, we conducted a set of simultaneous optical measurements to assess both the flow field and the distribution of fluid components within acoustically levitated droplets. To achieve this, we developed a technique to selectively separate fluorescent particles within each fluid, permitting the measurement of the concentration field based on the data from the discrete particle distribution. This approach revealed a relationship between the mixing process and the internal flow caused by surface oscillation. Thus, the internal flow induced by surface oscillation could enhance droplet mixing. Our findings will be conducive to the application and further development of lab-on-a-drop devices.

NIMG-81. ASSOCIATION OF THE ORIGIN OF CRANIOPHARYNGIOMA WITH OPTIC TRACT EDEMA

Abstract OBJECTIVE Optic tract edema (OTE) is a useful finding in the diagnosis of craniopharyngioma (CP). However, the pathogenesis of OTE is not fully understood. In this study, we investigated the presence of OTE depending on the site of origin of CP. METHODS We reviewed 48 patients with CP who underwent surgical treatment at Juntendo University Hospital between March 2010 and February 2023 and investigated their size, location, presence of OTE, pathological subtypes, and genetic abnormalities. Tumors were classified into four groups based on their origin: retrochiasmatic (RC) type, prechiasmatic (PC) type, intrasellar (IS) type, and intra-third-ventricle (ITV) type. RESULTS Forty-eight cases were included in this study. The number of cases of RC, PC, IS, and ITV types were 29, 8, 3, and 8, respectively. OTE was shown in 21 cases. Among them, RC type was the most common location (18 cases, 86%) with significant differences. The cystic component of the tumor was in contact with the optic tract in 15 cases, which was more common than the solid component. DISCUSSION Possible causes of OTE include cytotoxic edema associated with inflammation, angiogenic edema due to leakage of serum components from the tumor, leakage of fluid components from the cyst, and enlargement of the Virchow-Robin space in the optic disc. In this study, many of the cases with OTE have cystic components in contact with the optic tract, suggesting leakage of fluid components from the cyst as the pathogenesis of OTE. The presence of OTE can be a new factor to determine the surgical approach since CP with OTE is thought to extend posteriorly to the optic chiasm. CONCLUSIONS OTE is often associated with RC type CP and is thought to be caused by leakage of fluid from the cyst.

Methyl and Ethyl Ethers of Glycerol as Potential Green Low-Melting Technical Fluids.

The study is dedicated to the consideration of lower alkyl ethers of glycerol as potential components of low-melting technical fluids (e.g., heat transfer fluids, hydraulic fluids, aircraft de-icing fluids, etc.). Four isomeric mixtures of glycerol ethers (GMME-monomethyl; GDME-dimethyl; GMEE-monoethyl; GDEE-diethyl) were synthesized from epichlorohydrin and methanol/ethanol in the presence of sodium and subjected to detailed characterization as pure compounds and as aqueous solutions (30-90 vol%). The temperature and concentration dependencies of density, viscosity, cloud point, boiling range, specific heat capacity, thermal conductivity, and rubber swelling were obtained. On the basis of the data obtained, a comparison was made between the aqueous solutions of glycerol ethers and of other common bases for low-melting liquids (glycerol, ethylene glycol, and propylene glycol). Pure glycerol ethers could potentially be used as technical fluids in a very wide temperature range-from -114 to 150 °C. It was further demonstrated that in low temperature applications (e.g., in low-temperature chiller systems) the glycerol-ether-based aqueous heat transfer fluids could provide enhanced efficiency when compared to the glycerol- or propylene-glycol-based ones due to their lower viscosities and favorable environmental properties.