Liquid Beads Research Articles

First Discovery and Significance of Liquid Mercury in a Thermal Simulation Experiment on Humic Kerogen

We found for the first time enriched liquid mercury beads in a thermal simulation experiment on humic kerogen extracted from coal, which provided some kind of direct evidence that mercury can be re...

Ultra Cryo-Milling with Liquid Nitrogen and Dry Ice Beads: Characterization of Dry Ice as Milling Beads for Application to Various Drug Compounds.

Ultra cryo-milling using liquid nitrogen (LN2) and dry ice beads has been proposed as a contamination-free milling technique. The morphological change of dry ice beads was visually monitored in LN2 to clarify their production process and cryo-milling process. We found that dry ice pellets, which are starting material of beads and available on the market, immediately disintegrate in LN2, resulting in the spontaneous production of dry ice beads. In addition, the resultant beads maintain their size and shape even under vigorous agitation in LN2, demonstrating that they could play a role of milling media in the milling process. The driving conditions of this cryogenic milling process including beads size were optimized to enhance the milling efficiency. Dry ice beads provided superior milling efficiency compared to original pellets. The milling efficiency increased as the size of the dry ice beads decreased; furthermore, the larger the amount of beads used, the finer the milled particles. Any crystals of three drug compounds were effectively pulverized to the sub- or single-micron range. Cryo-milling with dry ice beads is valuable on pharmaceutical field because it does not contaminate the product with fractured and/or eroded beads.

Adsorption of malachite green from aqueous solution by using novel chitosan ionic liquid beads

Chitosan ionic liquid beads were prepared from chitosan and 1-butyl-3-methylimidazolium based ionic liquids to remove Malachite Green (MG) from aqueous solutions. Batch adsorption experiments were carried out as a function of initial pH, adsorbent dosage, agitation time and initial MG concentration. The optimum conditions were obtained at pH 4.0, 0.008g of adsorbent dosage and 20min of agitation time were utilized in the kinetic and isotherm studies. Three kinetic models were applied to analyze the kinetic data and pseudo-second order was found to be the best fitted model with R2>0.999. In order to determine the adsorption capacity, the sorption data were analyzed using the linear form of Langmuir, Freundlich and Temkin equations. The isotherm was best fitted by Langmuir isotherm model. The maximum adsorption capacity (qmax) obtained from Langmuir isotherm for two chitosan beads 1-butyl-3-methylimidazolium acetate A and 1-butyl-3-methylimidazolium B are 8.07mgg−1 and 0.24mgg−1 respectively.

Effects of Nozzle Geometry on the Fluid Dynamics of Thin Liquid Films Flowing down Vertical Strings in the Rayleigh-Plateau Regime.

Thin-liquid films flowing down vertical strings undergo instability, creating wavy film profiles and traveling beads. Previous studies assumed that the liquid film thickness and velocity profiles within the healing length from a nozzle were specified by the Nusselt solution, independent of the nozzle geometry. As a result, the influence of the nozzle diameter on the flow characteristics, such as the liquid bead size, spacing, and traveling speed, was largely overlooked. We report an experimental and numerical simulation study on liquid-film flows in the Rayleigh-Plateau regime while systematically varying the nozzle diameter from 0.5 to 3.2 mm at different mass flow rates (0.02, 0.04, 0.06, and 0.08 g/s). We find that the nozzle diameter does have a strong influence on the flow regime and the flow characteristics. We identify the thickness of a nearly flat portion of a liquid film that precedes the onset of instability, which we term the preinstability thickness, as a critical flow parameter that governs the size, spacing, and frequency of liquid beads that develop downstream. By defining the liquid film aspect ratio α in terms of the preinstability thickness, we capture a flow transition from the Rayleigh-Plateau (RP) instability regime to the isolated droplet regime. Improved understanding of the flow regimes and characteristics assists in the systematic design and optimization of a wide variety of processes and devices, including fiber coating and direct contact heat and mass exchangers.

In-situ testing of surface evolution of SiC during thermal ablation: Mechanisms of formation, flowing and growth of liquid silica beads

In this work we use real-time and in-situ observation technique at high temperature to capture the surface evolution of SiC (silicon carbide) specimen subjected to oxyacetylene torch flame. The obtained real-time images reveal clearly the nucleation, flowing and growth of the liquid silica beads on the surface of the specimen during thermal ablation process. A detailed model is developed to qualitatively analyze and interpret the mechanisms of the nucleation, flowing and the growth of the liquid silica beads. The result is expected to provide a better understanding of the ablation mechanism of SiC materials and serve as a preparatory work for the design and modification of the surface properties and topography of the materials to improve the thermal ablation resistance.

Experimental study of heat transfer between thin liquid films flowing down a vertical string in the Rayleigh-Plateau instability regime and a counterflowing gas stream

Direct contact heat exchangers based on wetted string columns offer an intriguing alternative to packed beds and spray columns. We experimentally examine the flow and heat transfer characteristics of thin liquid films flowing down strings of a diameter approximately 1mm against a counterflowing air stream. Numerical simulations are also performed to help interpret and validate our experimental results. The Rayleigh-Plateau instability caused by interplay among surface tension, gravity, and viscous forces leads to the formation of uniformly spaced drop-like liquid beads traveling down a string. The liquid mass flow rate and also the nozzle radius influence the radius and spatial/temporal frequency of liquid beads. Aerodynamic drag exerted by the counterflowing air stream deforms liquid beads. The relationship between flow characteristics and heat transfer effectiveness are examined experimentally for different combinations of the air velocities, liquid mass flow rates, and nozzle radii. We show that the liquid mass flow rate and the air velocity are two primary factors influencing heat transfer effectiveness whereas details of the liquid flow instability affect local bead-to-air heat transfer coefficients. We also compare the heat transfer effectiveness and the pressure drop between a wetted string column that consists of an array of vertical strings and a well-established structured packing that consists of vertical plates. The wetted string column is shown to deliver comparable heat transfer performance but at a lower air pressure drop than the structured packing. The present work helps improve our understanding of the flow and heat transfer performance of string-based direct-contact heat exchangers and helps build a foundation for their systematic design and optimization.

Cultivation of an immobilized (hyper)thermophilic marine microbial community in a bioreactor.

Cultivation in a bioreactor of immobilized deep-sea hydrothermal microbial community was tested in order to assess the stability and reactivity of this new system. A community composed of eight hydrothermal strains was entrapped in a polymer matrix that was used to inoculate a continuous culture in a gas-lift bioreactor. The continuous culture was performed for 41 days at successively 60°C, 55°C, 60°C, 85°C and 60°C, at pH 6.5, in anaerobic condition and constant dilution rate. Oxic stress and pH variations were tested at the beginning of the incubation. Despite these detrimental conditions, three strains including two strict anaerobes were maintained in the bioreactor. High cell concentrations (3 × 10(8) cells mL(-1)) and high ATP contents were measured in both liquid fractions and beads. Cloning-sequencing and qPCR revealed that Bacillus sp. dominated at the early stage, and was later replaced by Thermotoga maritima and Thermococcus sp. Acetate, formate and propionate concentrations varied simultaneously in the liquid fractions. These results demonstrate that these immobilized cells were reactive to culture conditions. They were protected inside the beads during the stress period and released in the liquid fraction when conditions were more favorable. This confirms the advantage of immobilization that highlights the resilience capacity of certain hydrothermal microorganisms after a stress period.

Comparison of GeneFinder human papillomavirus (HPV) Liquid Beads Microarray PCR Kit and Hybrid Capture 2 Assay for Detection of HPV Infection

Along with advances in methodological technologies, various assays for detecting high-risk human papillomavirus (HR HPV) have been introduced. The GeneFinder HPV liquid beads microarray PCR kit is one of the recently developed. Our aim was to compare the performance of GeneFinder to Hybrid Capture 2 for detection of HR HPV. A total of 900 cervical swab specimens were obtained. All specimens were submitted for HR HPV detection with Hybrid Capture 2 (HC2) and GeneFinder and then additionally analyzed the discordant or both positive results using restriction fragment mass polymorphism (RFMP) genotyping analysis. Hybrid Capture 2 detected 12.8% cases and GeneFinder detected 15.8% cases with 13 HR HPV types. Also, GeneFinder detected 27.4% cases for 32 detectable HPV types. The overall agreement rate was 93.2% with 0.724 kappa coefficient. Discordant results between these two assays were observed in 56 cases. HC2 showed sensitivity of 83.5% and specificity of 95.9%, while GeneFinder showed sensitivity of 85.4% and specificity of 91.9%. For HPV 16 or HPV 18 detection, GeneFinder showed 95.0% or 66.7% of sensitivity and 99.2% or 100%, respectively. Overall coinfection rate was 15.4% (38/247) in GeneFinder analysis. Considering the high agreement rate with HC2, high sensitivity and the ability to differentiate 32 HPV genotypes including HPV 16/18, GeneFinder could be used as a laboratory testing method for the screening of HPV infections. The use of GeneFinder may also contribute to future research associated with the significance of various HPV types and multiple coinfections.

754 exposures to reed diffusers reported to the United Kingdom National Poisons Information Service 2010–2014

Objective: The objective of this study is to review the reported toxicity of reed diffuser fragrance liquid which, in addition to essential oils, commonly contains glycol ethers but other ingredients and/or alternatives are 3-methoxy-3-methyl-1-butanol, petroleum distillates, ethanol and isopropanol. Methods: We analysed retrospectively enquiries to the United Kingdom National Poisons Information Service between 1 January 2010 and 31 December 2014. Results: 754 patients were exposed to reed diffusers; the majority (n = 712) were children < 5 years. Ingestion was the most common route of exposure (706 of 754 patients) and involved the liquid alone (n = 570), water beads alone (n = 84), sucking on the reeds (n = 31) or ingesting the liquid and water beads (n = 21). The reported amount of fragrance liquid ingested was known in only 76 of 591 cases (12.9%), with a median (IQR) volume of 20.0 (IQR = 10–40) mL. The WHO/IPCS/EC/EAPCCT Poisoning Severity Score (PSS) was known in 702 of 706 sole ingestions: in 574 (81.3%), the PSS was 0 (asymptomatic); in 117 (16.6%) patients, the PSS was 1 (minor toxicity); in 11 (1.6%), the PSS was 2 (moderate toxicity); there were no patients with features graded PSS 3 (severe toxicity). Significantly (p = 0.008) more patients became symptomatic (PSS 1 and PSS 2) following the ingestion of a reed diffuser containing 3-methoxy-3-methyl-1-butanol than propylene glycol monobutyl ether, though there was no significant difference when compared with those containing dipropylene glycol monomethyl ether (p = 0.181). The most common features following ingestion of fragrance liquid were nausea and vomiting (n = 53), coughing (n = 17) and CNS depression (n = 9). Seven patients suffered eye exposure alone: two developed eye pain and four conjunctivitis. Dermal exposure alone was reported in six patients, two of whom developed skin irritation. Conclusions: The majority of patients in our study developed no features or only minor symptoms following ingestion of reed diffuser fragrance liquid.

Tears of wine: new insights on an old phenomenon.

Anyone who has enjoyed a glass of wine has undoubtedly noticed the regular pattern of liquid beads that fall along the inside of the glass, or ‘tears of wine.’ The phenomenon is the result of a flow against gravity along the liquid film on the glass, which is induced by an interfacial tension gradient. It is generally accepted that the interfacial tension gradient is due to a composition gradient resulting from the evaporation of ethanol. We re-examine the tears of wine phenomenon and investigate the importance of thermal effects, which previously have been ignored. Using a novel experiment and simple model we find that evaporative cooling contributes significantly to the flow responsible for wine tears, and that this phenomenon occurs primarily because of the thermodynamic behavior of ethanol-water mixtures. Also, the regular pattern of tear formation is identified as a well-known hydrodynamic instability.

Serum immunoglobulin E and immunoglobulin G reactivity to Agaricus bisporus proteins in mushroom cultivation workers.

Background and Purpose:Although molds are regarded as the main fungal allergen sources, evidence indicates that spores of Basidiomycota including Agaricus bisporus (A. bisporus) can be also found at high concentrations in the environment and may cause as many respiratory allergies as molds. The aim of the present study was to evaluate specific immunoglobulin E (IgE) and immunoglobulin G (IgG) antibodies against A. bisporus via immunoblotting technique in individuals working at mushroom cultivation centers.Materials and Methods:In this study, 72 workers involved in the cultivation and harvest of button mushrooms were enrolled. For the analysis of serum IgE and IgG, A. bisporus grown in Sabouraud dextrose broth was harvested and ruptured by liquid nitrogen and glass beads. The obtained sample was centrifuged and the supernatant was collected as “crude extract” (CE). CE was separated via Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The separated proteins were transferred to a nitrocellulose filter and the bands responsive to IgE and IgG were identified by anti-human conjugated antibodies. All participants were screened in terms of total IgE level. Results:Among 72 workers, 18 (25%) had a total IgE level higher than 188 IU/mL. In SDS-PAGE, the CE of A. bisporus showed 23 different protein bands with a molecular weight range of 13-80 kDa. The sera of 23.6% and 55.5% of participants showed positive response, with specific IgE and IgG antibodies against A. bisporus in the blot, respectively. The bands with molecular weights of 62 and 68 kDa were the most reactive protein components of A. bisporus to specific IgE antibodies. Moreover, bands with molecular weights of 57 and 62 kDa showed the highest reactivity to IgG, respectively. Also, 62 and 68 kDa components were the most reactive bands with both specific IgG and IgE antibodies.Conclusion:The obtained findings revealed that A. bisporus has different allergens and antigens, which contribute to its potential as an aeroallergen in hypersensitivity-related reactions of the lungs.

Conveyance of helium–neon laser, polymer liquid and polystyrene (PS) beads through microoptofluidic channels of polydimethylsiloxane (PDMS)

In this work, the simultaneous conveyance of light, liquid, and microbeads in microoptofluidic channels was investigated experimentally. Based on soft lithography, the microoptofluidic channels were made of transparent polydimethylsiloxane (PDMS) with length of ~3 cm, height of ~134 μm, width of ~210 μm, and refractive index of light (n) of 1.41–1.42. These channels were intended to have the different bent angles (θb) from 15° to 90° and radii (R) of curvature from 0 to 10 mm, respectively. The colorless liquid polymer of Norland Optical Adhesive (NOA 89) was used as the core material of the channels. The NOA 89 had a higher n than that of PDMS to be capable of generating the total internal reflection of light with a collective angle (θcollect) 20°–21° and numerical aperture ~0.54. Using helium–neon (HeNe) red laser at a wavelength of 633 nm, the characterization of optical illumination showed that the optical losses of LCWs strongly depended on their bending degree with 0.056–0.060 dB/cm°. Finally, we demonstrated the motion of light delivered by microfluidic flows at an average speed of ~1 mm/s and the motion of 20-μm-diameter polystyrene beads at a flowing speed ~5 μm/s. The developed LCWs here may be further realized for a promising application on tracking and visualization of small objects such as cells within biological microsystems in the future.

Preparation of ZnAc/PVP Composite Fibers and ZnO Nanofibers

Zinc acetate (ZnAc)/PVP composite fibers were prepared by electrospinning technique and pure inorganic ZnO nanofibers were then obtained after the calcination of the composite fibers at 600°C for 2.5h. The effects of the parameters during the spinning process on the composite fibers and ZnO nanofibers were investigated. Uniform in diameters and continuous nanofibers without liquid beads could be obtained with the polymer concentration of 15%, the spinning voltage of 11kV, the receiving distance of 20cm and the rate of sample propulsion of 1.5uL/min. The XRD detection demonstrated the construction of ZnO for nanofibers after the calcinations of the composite fibers.

An electrohydrodynamic bioprinter for alginate hydrogels containing living cells.

In this work we present a bioprinting technique that exploits the electrohydrodynamic process to obtain a jet of liquid alginate beads containing cells. A printer is used to microfabricate hydrogels block by block following a bottom-up approach. Alginate beads constitute the building blocks of the microfabricated structures. The beads are placed at predefined position on a target substrate made of calcium-enriched gelatin, where they crosslink upon contact without the need of further postprocessing. The printed sample can be easily removed from the substrate at physiological temperature. Three-dimensional printing is accomplished by the deposition of multiple layers of hydrogel. We have investigated the parameters influencing the process, the compatibility of the printing procedure with cells, and their survival after printing.

Simulation of gas absorption into string-of-beads liquid flow with chemical reaction

This study is an attempt to investigate the chemical absorption of CO2 in aqueous monoethanolamine (MEA) solution in a wetted-wire column consisting of one wire. Computational fluid dynamics method along with volume of fluid model was employed for modeling of two-phase flow, mass transfer and chemical reaction inside the column. The modeling results were compared with available experimental data and very good agreement was achieved. The simulation results showed that the diameter and intervals of liquid beads increases by increasing the gas and liquid flow rates. The beads velocity increases by increasing the liquid flow rate and decreasing mass fraction of MEA in the liquid phase. Also, mass transfer resistance in the liquid phase reduces by formation of the beads. It was concluded that the developed model is capable to predict the effect of operating and physical parameters on the investigated chemical absorption process.

A rapid two-step algorithm detects and identifies macrolide and ß-lactam antibiotics resistance genes

Background: Antibiotic resistance has rapidly grown into a worldwide problem that threatens to compromise the effective treatment of a plethora of diseases. A two-step test algorithm was developed for detection and identification of macrolide and ß-lactamantibiotics resistance genes. Methods & Materials: Bacterial isolates were first tested by a multiplex real-time PCR (mRT-PCR) covering eight genes in relation to macrolide (msrA, ermA, ermB, and ermC) and ß-lactam (blaTEM, blaSHV, blaCTX-M-1, blaCTX-M-9) resistances and the presence of one or multiple resistance genes were determinedbymelting temperature (Tm) profile analyses. Amplification products with indistinguishable Tm profiles were tested subsequently by a liquid beads microarray assay (LBMA) assay with the eight resistance gene-specific probes. The clinical validity was evaluated on 340 clinical isolates with phenotypic antimicrobial susceptibility results used as the standard comparison methods. Results: It has been shown that 75% of isolates can be identify by mRT-PCR and melting temperature analyses only, while the rest 25% need both two approaches. An overall agreement of 96.6% (kappa = 0.93, 95% CI = 0.89-0.96)was observed between the mRT-PCR-LBMA and phenotypic methods. The sensitivities and specificities were 94.5% and 97.5% for macrolide and 92.6% and 98.4% for ß-lactam resistance determination, respectively. Conclusion: The two-step mRT-PCR-LBMA assay provided a cost-effective toolfor rapid determination of macrolide and ß-lactam antibiotic resistances.

In situ hybridization freeze-assisted punches (IFAP): technique for liquid-based tissue extraction from thin slide-mounted sections for DNA methylation analysis.

In situ hybridization-assisted punches (IFAP) are a low-cost method for extracting tissue from frozen slide-mounted sections as thin as 12 μm. The method synergizes well with standard histological workflows and uses in situ hybridization to target corresponding slide-mounted cryosections that contain the region of interest. Liquid beads of M-1 embedding matrix are applied and snap frozen, binding the matrix to the underlying tissue. Bead-tissue complexes are removed and DNA extracted using a high-salt method. IFAP-extracted DNA is suitable for downstream DNA methylation analysis.

Detection and genotyping of human papillomavirus by five assays according to cytologic results

Five assays for the detection of human papillomavirus (HPV) with different assay principles were evaluated. A total of 230 cervical swab specimens were collected from subjects according to the cytologic results. All specimens were tested by the following assays: hybrid capture 2 (HC2), two real-time PCR assays (Abbott RealTime HR and AdvanSure RealTime), liquid beads microarray (GeneFinder) and peptide nucleic acid-based array (PANArray). The HPV DNA of 99 samples was sequenced to identify genotypes. Concordance rates between the results for the identification of 14 high risk HPV genotypes by any two of the evaluated assays, except for AdvanSure RealTime, ranged from 83.0% to 88.3%, and those for the identification of genotypes 16 and 18, except for HC2, were 93.0% and 96.1%, respectively. The results for the evaluation of high risk HPV genotypes by HC2 agreed with those of the other assays in 76.5-86.5% of cases. Identification of HPV genotype by GeneFinder and PANArray corresponded with that by direct sequencing in 88.9% and 84.8% of sequenced samples. This study demonstrated that HC2 and the two real-time PCR assays could be used for routine HPV screening, and the other genotyping assays can be applied for epidemiologic surveillance.

Liquid film flow on structured wires: Fluid dynamics and gas‐side mass transfer

The liquid film flow on different structured wires and chains is observed experimentally to assess the suitability of a structured packing consisting of vertical wires. The results show that liquid beads as they appear on cylindrical wires are inhibited by certain chain geometries. This increases the flooding gas load up to F = 12 Pa0.5. As the stabilized film shows no liquid bead motion, the liquid velocity at the interface is less which results in lower gas‐side mass‐transfer coefficients. An estimation of the packing characteristics for different chain geometries with an assumed wire packing density of 40,000 wires/m2 is made. The interfacial area, mass‐transfer coefficients, and consequently the separation efficiency strongly depend on the liquid load. However, the proposed gas‐side separation efficiencies are slightly lower compared to common structured packings but the advantages are higher load limits, a better liquid distribution, and lower pressure drop. © 2012 American Institute of Chemical Engineers AIChE J, 59: 295–302, 2013

Liquid crystal beads constrained on thin cellulosic fibers: electric field induced microrotors and N–I transition

We directly visualize the response of nematic liquid crystal drops of toroidal topology threaded in cellulosic fibers, suspended in air, to an AC electric field and at different temperatures over the N–I transition. This new liquid crystal system can exhibit non-trivial point defects, which can be energetically unstable against expanding into ring defects depending on the fiber constraining geometries. The director anchoring tangentially near the fiber surface and homeotropically at the air interface makes a hybrid shell distribution that in turn causes a ring disclination line around the main axis of the fiber at the center of the droplet. Upon application of an electric field, E, the disclination ring first expands and moves along the fiber main axis, followed by the appearance of a stable “spherical particle” object orbiting around the fiber at the center of the liquid crystal drop. The rotation speed of this particle was found to vary linearly with the applied voltage. This constrained liquid crystal geometry seems to meet the essential requirements in which soliton-like deformations can develop and exhibit stable orbiting in three dimensions upon application of an external electric field. On changing the temperature the system remains stable and allows the study of the defect evolution near the nematic–isotropic transition, showing qualitatively different behaviour on cooling and heating processes. The necklaces of such liquid crystal drops constitute excellent systems for the study of topological defects and their evolution and open new perspectives for application in microelectronics and photonics.