Wide Range Of Ratios Research Articles

Oil/water separation through dual-channeled superhydrophobic/underwater superoleophobic meshes toward continuous processes

ABSTRACT A highly efficient continuous oil/water separation process is proposed where both superhydrophobic/superoleophilic oil-removing and superhydrophilic/underwater superoleophobic water-removing stainless steel meshes are installed at the bottom of the same container to construct a dual-channeled separator, in which agitation is applied to avoid the stratification of oil/water mixtures. Continuous oil/water separation is easily realized by this dual-channeled separator. Stainless steel meshes above 300-mesh afford separation efficiency higher than 99.5% for oils lighter than water such as gasoline, hexane, and heptane and oils heavier than water like carbon tetrachloride in a wide range of ratio of oil to water.

ANTIOXIDANT PROPERTIES OF THE DIHYDROQUERCETIN WITH ALPHA-TOCOPHEROL COMBINATIONS IN FREE RADICAL OXIDATION

Introduction. A significant factor in the manifestation of the compound antioxidant ability is a pattern of its interaction with other antioxidants, which affects the demonstrated final antioxidant effect. Flavonoids display different antioxidant capacities along with a wide range of biological activity, dihydroquercetin in particular. The role of the regenerating component in the cycles of mutual transformations in antioxidant systems is assumed for dihydroquercetin as it's a compound with a high profile of antiradical capacity. Here we focused on the nature of the antioxidant activity presentation in a composition consisting of dihydroquercetin and the essential antioxidant α-tocopherol. The combination was studied in a wide ratio range of the dihydroquercetin-α-tocopherol composition components from 1:1 to 1:20, based on the assumption that the concentration of the second component in living systems is excessive. Aim. The work aimed to determine the nature of the dihydroquercetin-α-tocopherol composition antioxidant activity in vitro, both in general and in terms of the individual component’s action. Material and methods. The antioxidant effects of the composition were studied within the framework of decolorization and kinetic methods based on the inhibition of model radical cations of 2,2'-azino-bis-(3-ethylbenzthiosoline-6-sulfonic acid) diammonium salt. To determine the nature of the individual components' action, high-resolution mass spectrometry was used, based on the analysis of the spectra of which kinetic curves of the consumption of the components of the composition were constructed. Results. A study of the interaction of dihydroquercetin with α-tocopherol by the decolorization method showed that a slight subadditive effect was observed for all ratios of the components of the compositions. The kinetic method revealed a two-stage nature of the antioxidant activity manifestation of the composition, with the first stage of the induction period being attributed to the α–tocopherol action, and the second to dihydroquercetin. In support of the hypothesis expressed, it was shown by high-resolution mass spectrometry that a decrease in the concentration of dihydroquercetin in the composition begins only after almost complete α-tocopherol consumption. Conclusions. α-Tocopherol prevents the oxidation of dihydroquercetin by radical cations ABTS•+ when acting together in the composition, and regeneration of one antioxidant by another does not occur.

Retrospective Analysis of Polyethylene Oxide and Polypropylene Oxide Block Copolymers Production and Industrial Applications (Review)

Introduction. Nowadays block copolymers of PEO and PPO (poloxamers, pluronics, proxanols) are among the most popular polymers in the pharmaceutical and biotechnological industries. They can be applied as effective nonionic surfactants, biological membrane stabilizers, elements of targeted delivery systems, solubilizers, as well as excipients in the technology of traditional dosage forms – gelling agents, lubricants, etc. For the past fifty years, the world's largest manufacturer of poloxamers has been the German chemical concern BASF. However, today in the Russian Federation there is a risk of defects, which defines the relevance of import substitution of this excipient.Text. The purpose of this review is to highlight the experience of production and implementation of PEO and PPO block copolymers into novel Russian scientists’ developments, comparing them with the experience of foreign research groups, which is necessary to assess the potential for import substitution. PEO and PPO block copolymers have been known in the Soviet Union since the late 60s as far as they are mentioned in textbooks of 1964 and 1973. Domestic block copolymers of PEO and PPO have been used in the oil refining industry, as well as in some branches of light industry and in the decontamination of radioactive waste. The unique domestic synthesis of PEO and PPO block copolymers was established in 1978 on the basis of the "Orgsintez" factory. Soviet poloxamers were produced under the brand name "proxanol" in a wide range of ratios of EO and PO units and molecular weights. It should be noted that today in the Russian Federation, industrial batches of the solubilizer Emuxol 268, which is close in its properties to the well-known poloxamer 188, are still produced, and block copolymers with other ratios of EO and PO units are synthesized to order.Conclusion. According to the retrospective analysis, the modern Russian industry has enough experience and resources to establish the synthesis of PEO and PPO block copolymers necessary to produce drugs and to develop innovative delivery systems and drugs. Based on the materials of the systematic review, the most complete register of known brands of PEO and PPO block copolymers synthesized over the past 50 years in our country and in the world was compiled for the first time, with a detailed description of their physicochemical properties.

Image-Based Feedback of Multi-Component Microdroplets for Ultra-Monodispersed Library Preparation.

Using devices with microfluidic channels can allow for precise control over liquids flowing through them. Merging flows of immiscible liquids can create emulsions with highly monodispersed microdroplets within a carrier liquid, which are ideal for miniaturised reaction vessels which can be generated with a high throughput of tens of thousands of droplets per second. Control of the size and composition of these droplets is generally performed by controlling the pumping system pushing the liquids into the device; however, this is an indirect manipulation and inadequate if absolute precision is required in the size or composition of the droplets. In this work, we extend the previous development of image-based closed-loop feedback control over microdroplet generation to allow for the control of not only the size of droplets but also the composition by merging two aqueous flows. The feedback allows direct control over the desired parameters of volume and ratio of the two components over a wide range of ratios and outperforms current techniques in terms of monodispersity in volume and composition. This technique is ideal for situations where precise control over droplets is critical, or where a library of droplets of different concentrations but the same volume is required.

Development of biotechnologically transesterified three-component fat systems stable to oxidation

The object of the research is the period of induction of accelerated oxidation of biotechnologically transesterified fatty systems that do not contain trans isomers of fatty acids. The paper defines the rational ratio of fatty raw materials in mixtures for biotechnological transesterification. The results obtained make it possible to develop biotechnologically transesterified three-component fat systems (palm stearin, coconut and sunflower, or soybean, or corn, or sesame oil) to obtain substitutes for milk fat. The proposed calculation of melting points of transesterified fat systems of a wide range of ratios of raw components allows us to justify such rational ratios of components that allow obtaining finished products with a melting point of 33.0...33.5 °С. It is effective to use the products of the developed composition in view of the technological requirements of consumers for their oxidizing capacity. The data obtained in the work are explained by the fatty acid and antioxidant composition of low-melting components of fat systems in a different range of their ratios, which determines different technological properties, in particular, the melting point and stability to oxidation of finished products. A feature of the obtained results is the competitiveness of the obtained fat systems, which are characterized by the absence of atherogenic components and the presence of biologically valuable polyunsaturated fatty acids in the composition. The results of the research make it possible to minimize the cost of raw components while preserving the nutritional value and technological characteristics. An applied aspect of using the scientific result is the possibility of expanding the range of milk fat substitutes with high nutritional value

Perforation of carbon fiber reinforced plastic laminates struck transversely by hemispherical-nosed projectiles

This study focuses on perforation of carbon fiber reinforced plastic (CFRP) laminates struck transversely by hemispherical-nosed projectiles. Global deformation with local rupture failures for thin laminates and localized response failures for thick laminates are two common categories of the ballistic perforation of CFRP laminates. An analytical model is proposed considering these two failure modes and their transition conditions. The ballistic limit predicted for laminates in global deformation with a local rupture failure mode is given based on the energy dissipation method, and an ultimate perforation failure criterion is derived based on the bottom surface tensile fracture of the laminate. A critical transition condition of the two failure modes is obtained by combing the localized response failure model and Von Karman’s critical impact velocity concept. Model predictions agree with the experimental and numerical results regarding ballistic limits in a wide ratio range of laminate thickness H and hemispherical-nosed projectile diameter d.

A Self-Crystallized Nanofibrous Ni-GDC Anode by Magnetron Sputtering for Low-Temperature Solid Oxide Fuel Cells.

The optimum composition ratio of the anode cermet (Ni-GDC) for solid oxide fuel cells (SOFCs) varies because the electron-collecting mechanism is different depending on its applications. A Co-sputtering method facilitates ratio control with sputtering power adjustment. However, there is a practical issue with fabricating anode cermet with various ratios attributed to the large sputtering yield gap of the metal target, Ni, and the ceramic target, gadolinia-doped ceria (GDC). Therefore, in this study, a Gd-Ce metal alloy was applied instead of GDC to match the sputtering rate with that of Ni, which enables a wide ratio range achievement. A thin film of Gd-Ce oxidized after deposition and successfully transformed to crystallized GDC under a SOFC operation environment. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) confirmed its crystallinity, and the film deposited with various power ratios was sputtered on the ScSZ electrolyte pellet to clarify the optimum Ni-GDC ratio for thin-film SOFCs. Last, the Ni-GDC was applied to anodized aluminum oxide (AAO)-supported SOFCs to maximize the performance. The performance change according to the thickness of Ni-GDC was identified, and the best performance among them was 638 mW/cm2 at 500 °C.

Quantification of Phagocytosis Using Flow Cytometry.

Phagocytosis is relevant for many research fields and is often measured as a functional outcome. However, accurate quantification can be challenging, and many researchers find it difficult to study in a robust manner. There are many ways to measure phagocytosis, but what is often overlooked is the importance of experimental design and how the analysis is planned and performed. Experimental factors like reaction volume, time, and phagocyte-prey concentrations often have a large impact on the outcome, as is the choice of detection strategy with different fluorescent or colorimetric labels of prey and phagocyte. By using dose-response curve principles for both experimental design and analysis, it is possible to increase the sensitivity and robustness, leading to accurate quantification of phagocytosis that is comparable across experiments and systems.Here, we describe how to quantify phagocytosis using flow cytometry with a robust, high-throughput, and easy-to-use approach. The prey is first fluorescently double stained, followed by optional opsonization before being introduced to the phagocyte in a wide range of ratios. After incubation, data is acquired through flow cytometry. It can be assessed on both the population and single-cell level of the phagocytes, separating adhesion and internalization. As an example, we provide an experimental protocol for studying phagocytosis of opsonized Streptococcus pyogenes using the THP-1 cell line. This approach is easily incorporated into most existing phagocytosis assays and allows for reproducible results with high sensitivity.

A 2D layered cobalt-based metal–organic framework for photoreduction of CO2to syngas with a controllable wide ratio range

A two-dimensional cobalt-based metal–organic framework provides an available concept for the design of heterogeneous photocatalysts that can reduce CO2to a controllable syngas using solar energy.

Microemulsion system formed with new piperazinium-based surface-active ionic liquid

The intensive use of ionic liquid (IL) in various researches and applications induces the imperative need of specific functional ILs. Present work introduces a novel piperazinium-based surface-active IL (SAIL) which shows great potential for the preparation of microemulsion (ME), namely 1-(2-hydroxyethyl)piperazinium laurate ([HEP][C11CO2]). Important fundamental physicochemical properties have been investigated, revealing higher surface activity for the SAIL than common surfactants. [HEP][C11CO2] is able to solubilize different oil components and water with short-chain alcohol as cosurfactant, forming stable ME in a wide range of ratio of water to oil, and a broad microemulsion region covering over 50 % of the pseudo-ternary phase diagram can be found. The structural transition of water-in-oil to bicontinuous occurs at the water content of 0.60 to 0.65 for the SAIL/1-butanol/n-heptane/water systems at the ratios of SAIL to 1-butanol of 1:1 and 1:2, as confirmed by electrical conductivity measurements. Moreover, the solubilization of oil and water was investigated in the presence of NaCl, KCl or MgCl2, and the optimal salinity was determined. While Mg2+ induces formation of emulsion probably due to the poor solubility of Mg2+/[C11CO2]− complexes, the ME system is much more stable with the presence of monovalent ions like Na+ and K+. For the NaCl-contained system, the salinity window of the bicontinuous phase changes from 0.030 to 0.025 and 0.020 when the temperature rises from 15 °C to 25 °C and 35 °C, which mainly results from the enhanced hydrophobic interactions and the weakened electrostatic interactions. Present studies elucidate that [HEP][C11CO2] is feasible to form various microemulsion systems which may have extensive potential in further applications like size-controlled syntheses and oil recovery.

Effect of Soil Particle Size on the Accuracy of Tactile Pressure Sensors

This paper investigates the effects of soil particle size on the measurement accuracy of single-point type tactile pressure sensors when used for measuring soil contact stresses. Sensors with two different diameters (Dsens) are integrated into an oedometer cell. Granular materials with a wide range of particle diameters (D50) and angularities (from rounded to irregular shaped) are evaluated, resulting in a wide range of ratios of Dsens/D50 from 2.6 to 105.8. The test results show that the soil particle size significantly affects and exponentially correlates with the measurement accuracy of the sensor. A threshold Dsens/D50 of 10.5 is identified for the sensor, beyond which the error is less than 5%. It is also shown that even for ratios of Dsens/D50 as large as 40, an error of approximately 2% can be observed, which is intrinsic to the sensor.

Kinetics of benzoxazine and epoxy oligomer copolymerization

This work is devoted to the non-isothermal kinetic analysis of the curing process of benzoxazine - epoxy alloys in a wide range of ratios by the DSC method. Compositions consisted of benzoxazine (BA-mt) based on bisphenol A and m-toluidine and epoxy resin based on bisphenol A (KER 828). The dependencies of the isoconversional activation energy on the extent of conversion for all systems were obtained according to the methods developed by Vyazovkin. These dependencies indicated a complex multi-step curing mechanism. Based on the calculated values ​​of the isoconversional activation energy dependencies, some isothermal predictions were made. It is shown that in order to derive an optimal mathematical model that describes well the real process under isothermal conditions, it is necessary to take into account diffusion limitations, which may be associated with the process of vitrification of systems during the curing process. The possibility of vitrification of systems was proved in terms of oscillatory rheology. In general, it was shown that the addition of epoxy oligomer to the benzoxazine resin significantly slowed down the curing process. However, we suppose that cure for all systems under study was complete, that was confirmed by FTIR data. The kinetic model for the curing process of BA-mt benzoxazine was derived.

BIO25: Pediatric Continuous-Flow Total Artificial Heart Performance: Current Development Update

Background: The pediatric continuous-flow total artificial heart (P-CFTAH) is a novel mechanical circulatory support system intended for pediatric population with end-stage heart failure. P-CFTAH has been evaluated in animal models and additional design modifications or adjustments from multiple perspectives are ongoing. Herein, we report a thorough summary and update on the P-CFTAH development. Methods: A working prototype of the P-CFTAH was fabricated at the scale of 0.70 of adult CFTAH, and human intraoperative fitting study was performed to determine the range of appropriate anatomical fit for this device. In vivo studies (n=2) with healthy lambs (20.5 and 22.4 kg) were performed through a full median sternotomy. As a parallel effort, computational fluid dynamics (CFD) analyses were performed to guide and evaluate the pump’s flow path design. Results: From the fitting study, we analyzed and concluded that the P-CFTAH could be implanted in children over 5.7 kg of body weight and 0.31 m2 of body surface area. In vivo animal experiments, the anatomical and surgical fit of the P-CFTAH was optimal. All implantations were uncomplicated, and the P-CFTAH ran as expected during the experiment over a wide range of ratios of systemic/pulmonary vascular resistance (0.1 to 37.4). The CFD results were used to select the nominal bearing radial clearance, visualize the flow field throughout the pump, and identify potential flow-related improvements for a next generation design. Conclusion: The P-CFTAH has demonstrated optimal anatomical fitting in small-size models and reasonable selfregulation in various test configurations.

A new equivalent sand grain roughness relation for two-dimensional rough wall turbulent boundary layers

The effects of different geometries of two-dimensional (2-D) roughness elements in a zero pressure gradient (ZPG) turbulent boundary layer (TBL) on turbulence statistics and drag coefficient are assessed using single hot-wire anemometry. Three kinds of 2-D roughness are used: (i) circular rods with two different heights, $k= 1.6$ and 2.4 mm, and five different streamwise spacing of $s_{x}= 6k$ to $24k$ , (ii) three-dimensional (3-D) printed triangular ribs with heights of $k= 1.6$ mm and spacing of $s_{x}= 8k$ and (iii) computerized numerical control (CNC) machined sinewave surfaces with two different heights, $k= 1.6$ and 2.4 mm, and spacing of $s_{x}= 8k$ . These roughnesses cover a wide range of ratios of the boundary layer thickness to the roughness height ( $23 < \delta /k < 41$ ), where $\delta$ is the boundary layer thickness. All roughnesses cause a downward shift on the wall-unit normalised streamwise mean velocity profile when compared with the smooth wall profiles agreeing with the literature, with a maximum downward shift observed for $s_{x}= 8k$ . In the fully rough regime, the drag coefficient becomes independent of the Reynolds number. Changing the roughness height while maintaining the same spacing ratio $s_{x}/k$ exhibits little influence on the drag coefficient in the fully rough regime. On the other hand, the effective slope $(ES)$ and the height skewness $(k_{sk})$ appear to be major surface roughness parameters that affect the drag coefficient. These parameters are used in a new expression for $k_{s}$ , the equivalent sand grain roughness, developed for 2-D uniformly distributed roughness in the fully rough regime.

Au/MoS2 tips as auxiliary rate aligners for the photocatalytic generation of syngas with a tunable composition

Synthesis gas (syngas), with a wide range of molar ratios of CO and H2 from 0.3 to 4, can serve as an important feedstock in the petroleum industry for the production of various synfuels; however, it remains a major challenge to tune the composition over such a wide range of ratios. Here, we demonstrate the photocatalytic production of syngas with tunable H2/CO molar ratios via rationally designed Au/MoS2 symmetrically tipped CdS nanowires (AMTCs), in which MoS2 and Au serve as cocatalysts for the hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR), respectively. The competing reactions are controlled and aligned through the selective decoration of size-controlled (1–50 nm) Au nanoparticles on MoS2 by controlling the charge transfer kinetics during photodeposition. Finally, the widest range of H2/CO ratios in syngas reported to date, ranging from 0.35 to 3.6, is realized, indicating that this is a potentially efficient approach for solar-to-syngas production by using rationally designed nanostructures.

Impact of the COVID-19 Pandemic on the Energy Use at the University of Almeria (Spain)

The COVID-19 pandemic has caused chaos in many sectors and industries. In the energy sector, the demand has fallen drastically during the first quarter of 2020. The University of Almeria campus also declined the energy consumption in 2020, and through this study, we aimed to measure the impact of closing the campus on the energy use of its different facilities. We built our analysis based upon the dataset collected during the year 2020 and previous years; the patterns evolution through time allowed us to better understand the energy performance of each facility during this exceptional year. We rearranged the university buildings into categories, and all the categories reduced their electricity consumption share in comparison with the previous year of 2019. Furthermore, the portfolio of categories presented a wide range of ratios that varied from 56% to 98%, the library category was found to be the most influenced, and the research category was found to be the least influenced. This opened questions like why some facilities were influenced more than others? What can we do to reduce the energy use even more when the facilities are closed? The university buildings presented diverse structures that revealed differences in energy performance, which explained why the impact of such an event (COVID-19 pandemic) is not necessarily relevant to have equivalent variations. Nevertheless, some management deficiencies were detected, and some energy savings measures were proposed to achieve a minimum waste of energy.

Метод расчета поверхностных механических напряжений в осесимметричных магнитных системах

A method is proposed for calculating the mechanical stresses of magnetic and current systems, calculated from the energy density of a uniformly magnetized cylinder. For the calculation, an average in volume demagnetizing factor of the cylinder is introduced, which is proportional to the ratio of the cylinder diameter to its length . It is shown that the demagnetization energy , negligible for a "long" cylinder , ( ), becomes decisive in the formation of stresses at . The radial and axial stresses are investigated in a wide range of ratios.

Integrated Interaction Diagrams for Sections Subjected to Axial Force and Bending Moment According to the American Concrete Institute and the Saudi Building Code

The Saudi Building Code for the design of concrete structures (SBC304) is identical to the American Concrete Institute metric code (ACI318M-19); therefore, any design aids developed for one of them could be used for the other. When designing a reinforced concrete section that is subjected to an axial force accompanied by a bending moment, an interaction diagram is needed. Most textbooks provide interaction diagrams based on imperial units and only a few provide these interaction diagrams based on metric units. Moreover, the new proposed interaction diagrams have advantages compared with the available diagrams in the textbooks. They do not only consider axial compression forces but also tension forces. The portion above the maximum allowable axial compression force is not displayed in these diagrams to prevent users from using this part of the diagrams since according to the code requirements, which is not permissible. In addition, these diagrams allow one to use ratios of compression to tension reinforcement different than 1.0, which is the only ratio available in the textbooks. A wide range of ratios for the lever arm of extreme reinforcement to the section depth is presented in the diagrams with a 0.05 step. Also, numerous values of concrete strength (fc\ ) ranges are covered. Finally, along with the nominal interaction diagram plots, ultimate (design) interaction diagrams are created as well, which provide easier usage. To verify the accuracy of these interaction diagrams, several examples from many textbooks were resolved using these diagrams and the results were shown to be compatible.

Uncompatibilized PBAT/PLA Blends: Manufacturability, Miscibility and Properties.

Polymer blends of poly(butylene adipate-co-terephthalate) (PBAT) and polylactide (PLA) have been drawn attention due to the application potential as packaging or agricultural films. This study aims to determine the manufacturability, miscibility and mechanical properties of uncompatibilized PBAT/PLA blends prepared using different techniques. First, PBAT and PLA are melt-blended in a wide range of ratios from 90/10 to 10/90. The compounds are then processed into pressed panels, flat films and blown films. Finally, the thermal, morphological, rheological and mechanical properties of these blends are investigated. PBAT/PLA blends have a small difference of solubility parameters, predicting theoretically good miscibility. However, they show two almost unchanged glass transition temperatures in the DSC, phase separation in SEM and two relaxation mechanisms in the Cole–Cole plot. The phase morphology varies depending on both the blend ratios and the preparation techniques. Tensile tests indicate that with increasing PLA content the elongation at break decreases. A good correlation between the elongation at break and the tear propagation resistance is found. Furthermore, the trouser tear method is proven to be more applicable to differentiate highly extensible blown films compared with the Elmendorf tear method.

A role for cell-autocrine interleukin-2 in regulatory T-cell homeostasis.

Activated T-cells make both interleukin-2 (IL2) and its high-affinity receptor component CD25. Regulatory CD4 T-cells (Treg cells) do not make IL2, and the IL2-CD25 circuit is considered a paracrine circuit crucial in their generation and maintenance. Yet, all T-cells are capable of making IL2 at some stage during differentiation, making a cell-intrinsic autocrine circuit additionally possible. When we re-visited experiments with mixed bone marrow chimeras using a wide range of ratios of wild-type (WT) and IL2-/- genotype progenitors, we found that, as expected, thymic Treg cells were almost equivalent between WT and IL2-/- genotypes at ratios with WT prominence. However, at WT-limiting ratios, the IL2-/- genotype showed lower thymic Treg frequencies, indicating a role for cell-intrinsic autocrine IL2 in thymic Treg generation under IL2-limiting conditions. Further, peripheral IL2-/- naive CD4 T-cells showed poor conversion to inducible Tregs (pTregs) both in vivo and in vitro, again indicating a significant role for cell-intrinsic autocrine IL2 in their generation. Peripherally, the IL2-/- genotype was less prominent at all WT:IL2-/- ratios among both thymic Tregs (tTregs) and pTregs, adoptively transferred IL2-/- Tregs showed poorer survival than WT Tregs did, and RNA-seq analysis of WT and IL2-/- Tregs showed interesting differences in the T-cell receptor and transforming growth factor-beta-bone morphogenetic protein-JNK pathways between them, suggesting a non-titrating role for cell-intrinsic autocrine IL2 in Treg programming. These data indicate that cell-intrinsic autocrine IL2 plays significant roles in Treg generation and maintenance.