Small Amount Of Liquid Research Articles

Highly Nonlinear Liquid Surface Waves in the Dynamics of the Fluid Balancer

This paper is concerned with the dynamics of a cylindrical vessel containing a small amount of liquid which, during rotation, is spun out to form a thin liquid layer on the outermost inner surface of the vessel. The liquid is able to counteract unbalanced mass in an elastically mounted rotor. Hence the name ‘fluid balancer’. The paper discusses the equations of motion for the coupled fluid-structure system, their solution in terms of a perturbation method, and how they can explain the working principle of the fluid balancer.

Evaluation of cell inkjet printing technique for biofabrication

AbstractThe main goal in biofabrication approach is to build living tissue substitutes on demand. In order to create functional tissue structures, additive manufacturing (AM) technologies are being increasingly considered. They allow generating functional structures created out of CAD models within a short period of time and with a very high precision. Different techniques are already established to build three-dimensional (3D) complex cell-loaded structures. One of these robotic additive fabrication techniques is the ink jet technology which is highly promising for biofabrication. This technique allows to process very small amounts of liquids or low-viscous polymer solutions e.g. to set biomolecules and cells in a suitable structure. The aim of this study is to evaluate a piezo inkjet printing device which is integrated in a commercial modular instrument platform together with a bioplotting system for biofabrication. The inkjet device is able to print single ink droplets of different volumes by controlling the applied voltage and the number of drops released to the spot. In this work different selective sets of parameters influencing the droplet formation and the spot size have been investigated. It has been proven that inkjet printing process in combination with fibrin hydrogel and bone marrow stromal cells is cytocompatible. In summary, the applied piezo inkjet printing is shown to be completely programmable, accurate and the resolution of the device allowed printing of various patterns with biomaterials and vital cells.

Reversed-phase Chromatography in an Extended Nanospace: Separating Amino Acids in Short and Long Nanochannels

Micro- and nanofluidics has attracted much attention, particularly concerning single-cell analysis when small amounts of liquids are examined. In present work we successfully fabricated extended-nano channels that were more narrow and shorter (2 mm) as well as wider and longer (10 mm), and accomplished a reversed-phase HPLC separation of labeled amino acids on these channels after octadecylsilylation (ODS). The separation performance characteristics were compared for both types of nano spaces. At an equal amount of pressure, the longer extended-nano channels showed permeability that was one-order higher (K = 47 × 10(-14) m(2)) and separation impedance (E = 13) that was one-order lower than that of the shorter version. Also, the separation plate number for the longer channel was 4000 with a plate height of 2.5 μm. Both channels have advantages for use in single-cell analysis. The longer channel can be applied for the separation of macromolecules (proteomics), while the short version is more applicable to small molecules (amino acids).

Exploration and exploitation of water in colloidal crystals.

Water on solid surfaces is ubiquitously found in nature, in most cases due to mere adsorption from ambient moisture. Because porous structures have large surfaces, water may significantly affect their characteristics. This is particularly obvious in systems formed by separate particles, whose interactions are strongly influenced by small amounts of liquid. Water/solid phenomena, like adsorption, condensation, capillary forces, or interparticle cohesion, have typically been studied at relatively large scales down to the microscale, like in wet granular media. However, much less is known about how water is confined and acts at the nanoscale, for example, in the interstices of divided systems, something of utmost importance in many areas of materials science nowadays. With novel approaches, in-depth investigations as to where and how water is placed in the nanometer-sized pores of self-assembled colloidal crystals have been made, which are employed as a well-defined, versatile model system with useful optical properties. In this Progress Report, knowledge gained in the last few years about water distribution in such nanoconfinements is gathered, along with how it can be controlled and the consequences it brings about to extract new or enhance existing material functionalities. New methods developed and new capabilities of standard techniques are described, and the water interplay with the optical, chemical, and mechanical properties of the ensemble are discussed. Some lines for applicability are also highlighted and aspects to be addressed in the near future are critically summarized.

Capabilities of sequential and quasi-simultaneous LA-ICPMS for the multi-element analysis of small quantity of liquids (pl to nl): insights from fluid inclusion analysis

Three configurations of LA-ICPMS (quadrupole, sector-field, time-of-flight) were compared for multi-element analysis of small quantities of liquids (pl to nl), such as fluid inclusions.

Computational fluid dynamics modeling of fluid flow and heat transfer in the central pore of carbon nanopipes

Carbon nanopipes, which can be employed in micro- and nano-fluidic devices, have some extraordinary mechanical, optical, flow and electrical properties. In addition, these devices can manipulate very small amounts of liquid. One of the main aspects of these pipes is an unusual enhancement in the flow rate, and it should be explored whether this enhancement can be justified by continuum fluid mechanics or not. Computational fluid dynamics were employed for exploring this phenomenon. To explore this unusual flow enhancement, different parameters, such as temperature, inlet pressure, tube diameter, tube length and slip length were used. With varying parameters, the slip length can explain this phenomenon. The heat transfer was also numerically investigated and an improvement in the heat transfer coefficient and the convective heat flux magnitude were observed for the carbon nanopipes. Then, based on the numerical investigation, correlations were developed for the friction factor and the Nusselt number, and these correlations were verified by the reported experimental data for nanopipes. Moreover, the effects of this slip length on the velocity profile was investigated and the observed shape of the velocity profile was also completely changed from convex to plug-like by importing the effect of slip length on the walls of the tubes.

On the dynamics of the fluid balancer

This paper is concerned with the dynamics of a so-called fluid balancer; a hula hoop ring-like structure containing a small amount of liquid which, during rotation, is spun out to form a thin liquid layer on the outermost inner surface of the ring. The liquid is able to counteract unbalanced mass in an elastically mounted rotor. The paper derives the equations of motion for the coupled fluid–structure system, with the fluid equations based on shallow water theory. An approximate analytical solution is obtained via the method of multiple scales. For a rotor with an unbalance mass, and without fluid, it is well known that the unbalance mass is in the direction of the rotor deflection at sub-critical rotation speeds, and opposite to the direction of the rotor deflection at super-critical rotation speeds (when seen from a rotating coordinate system, attached to the rotor). The perturbation analysis of the problem involving fluid shows that the mass center of the fluid layer is in the direction of the rotor deflection for any rotation speed. In this way a surface wave on the fluid layer can counterbalance an unbalanced mass.

Effect of hydrogen addition to CNG in a biodiesel-operated dual-fuel engine

Alternative fuels for diesel engine applications are gaining more prominence as they have numerous advantages compared to fossil fuels. They are renewable, biodegradable; provide food and energy security and foreign exchange savings. They address environmental concerns and socio-economic issues as well. Gaseous fuels such as compressed natural gas and hydrogenated compressed natural gas (HCNG) appear more attractive fuels for diesel engine applications operated in dual-fuel mode. Such dual fuel engines can replace considerable amount of liquid-injected pilot fuels by gaseous fuels besides being friendly to the environment. A small quantity of liquid fuel injected towards the end of the compression stroke initiates combustion of the inducted gas in the dual-fuel engines. The main advantage of dual-fuel engines is their lower nitrogen oxides (NOx) and particulate emissions. Hence renewable fuels such as biodiesels and gaseous fuels can be used predominantly for transportation and power generation applications. Gaseous fuels are clean burning and are more economical as well. A suitable carburettor was designed to supply a stoichiometric mixture of air and HCNG to the modified diesel engine operated in dual-fuel mode. The biodiesel used in this study is derived from Honge oil called the Honge oil methyl ester (HOME). This paper presents the performance, combustion and exhaust emission characteristics of a single cylinder, four stroke, direct injection, stationary diesel engine operated on HOME and HCNG in dual-fuel mode. From the results it is observed that HOME–HCNG combination gave lower brake thermal efficiency (BTE) and improved emission levels when compared with diesel/HOME in single fuel operation. Lower smoke and particulate matter were obtained with dual-fuel operation. Comparative measures of BTE, peak pressure, pressure–crank angle variation, smoke opacity, hydrocarbon, carbon monoxide and NOx emissions have been made and analysed.

Comparative study on novel test systems to determine disintegration time of orodispersible films

Orodispersible films (ODFs) are a promising innovative dosage form enabling drug administration without the need for water and minimizing danger of aspiration due to their fast disintegration in small amounts of liquid. This study focuses on the development of a disintegration test system for ODFs. Two systems were developed and investigated: one provides an electronic end-point, and the other shows a transferable setup of the existing disintegration tester for orodispersible tablets. Different ODF preparations were investigated to determine the suitability of the disintegration test systems. The use of different test media and the impact of different storage conditions of ODFs on their disintegration time were additionally investigated. The experiments showed acceptable reproducibility (low deviations within sample replicates due to a clear determination of the measurement end-point). High temperatures and high humidity affected some of the investigated ODFs, resulting in higher disintegration time or even no disintegration within the tested time period. The methods provided clear end-point detection and were applicable for different types of ODFs. By the modification of a conventional test system to enable application for films, a standard method could be presented to ensure uniformity in current quality control settings.

Accurate Measurements of Liquid-Condensate Rate With Multiphase-Metering Technology Improve Ecological Impact of Well Test in Deepwater Well Offshore Brazil

Summary Separators have a proven track record and are widely used in well-testing operations. However, their range of applications is relatively narrow, and they can encounter limitations with fluids for which separation quality is an issue. This paper describes a well test in a deepwater well offshore Brazil. To be able to accommodate different production scenarios, two separators and a multiphase meter were used to measure the flow rates. During the test, a comparison of the flow rates from the multiphase flowmeter and those reported by the separator made possible the identification of some carry-over in the separator at a high choke setting. When the choke size was increased, the separator gas rate increased, whereas the liquid rate dropped at the separator, resulting in a very low condensate/gas ratio (CGR). The multiphase meter, on the other hand, reported a constant CGR, allowing for the real-time diagnostic that carry-over was occurring at the separator. At the end of the test, the same increased choke setting was used for a short period of time to confirm the behavior. The same rate results were observed for each phase, and a small amount of liquid could be seen in the gas flare. The final proof came from the analysis of the downhole samples, which confirmed the CGR measured with the multiphase meter. The consistent results from the multiphase meter make the meter ideal to validate the flow-rate measurements from the reservoir and to improve the burning efficiency. By allowing early identification of imperfect separation, the multiphase meter reduces the health, safety, and environmental (HSE) risks associated with well-test operations.

Setting time and formability of calcium phosphate cements prepared using modified dicalcium phosphate anhydrous powders

Calcium phosphate cements (CPCs) were prepared using Ca4(PO4)2O (TeCP) and modified CaHPO4 (DCPA) to evaluate the effects of the powder properties for DCPA particles on the setting time and formability of the resulting CPCs. Two types of modified DCPA were prepared by milling commercially available DCPA with ethanol (to produce E-DCPA) or distilled water (to produce W-DCPA). The E-DCPA samples consisted of well-dispersed, fine primary particles, while the W-DCPA samples contained agglomerated particles, and had a smaller specific surface area. The mean particle size decreased with increased milling time in both cases. The raw CPC powders prepared using W-DCPA had a higher packing density than those prepared using E-DCPA, regardless of the mean particle size. The setting time of the CPC paste after mixing with distilled water decreased with decreases in the mean particle size and specific surface area, for both types of DCPA. The CPCs prepared using W-DCPA showed larger plasticity values compared with those prepared using E-DCPA, which contributed to the superior formability of the W-DCPA samples. The CPCs prepared using W-DCPA showed a short setting time and large plasticity values, despite the fact that only a small amount of liquid was used for the mixing of the raw CPC powders (a liquid-to-powder ratio of 0.25g g(-1) was used). It is likely that the higher packing density of the raw CPC powders prepared using W-DCPA was responsible for the higher performance of the resulting CPCs.

Mixing of Liquids With a Rotating Current Density

Numerical tools to study the propulsion of a small amount of liquid using a rotating current density and a fixed magnetic field are developed and applied to mixing processes. Results are compared with dye advection experiments and the period of the rotating current that maximizes the perimeter of a blob is determined.

English

In this work, we propose and demonstrate the fabrication of an optical fiber sensor based on multimode interference effects (MMI) for rum quality control. The operation of the sensor relies on the fact that when rum is adulterated, which can be done either with ethanol or ethylene glycol, the refractive index (RI) of the adulterated rum will be different as compared to the original rum. Since the white rum (Bacardi®) has a RI close to 1.345 and the highest RI of the contaminant is 1.412 (ethylene glycol), the RI of the adulterated rum will increase as the volume of the contaminant is increased. Therefore, considering that the MMI sensor exhibits a sensitivity of 258.06 nm/RIU for liquids with RI ranging from 1.318 to 1.4203, we can accurately determine if a rum sample is free of contaminants or adulterated with other liquid, which is typically performed using ethanol or toxic elements like ethylene glycol. Although the sensor cannot determine which kind of liquid is altering the rum, it can easily detect when the original rum has been adulterated, even with small amounts of liquid. The sensor also provides high repeatability and reversibility while using a fast and simple fabrication process.

Discrete particle simulations and experiments on the collapse of wet granular columns

Small quantities of liquid in a granular material control the flow dynamics as well as the triggering and jamming phases. In order to study this problem, some experimental collapse tests conducted in a rectangular box were reproduced with a 1:1 scale numerical model using the Discrete Element Method. In simulations the effect of the capillary bridges has been investigated implementing a mid-range attractive force between particles based on the minimum energy approach. Also a bonding-debonding mechanism was incorporated in the algorithm and the volume of each sessile drop on the particle surface was considered during its motion. The influence of some variables was investigated with respect to the final slope profiles and the runout lengths: the initial liquid content, the particle size, the solid density, the liquid surface tension, and the liquid-solid contact angle. Also the crucial effect of the confinement walls on the collapse phenomenon was investigated: wet particles adhere to the lateral walls providing a higher flow resistance in comparison to the same material in dry conditions. It was observed that particles with largest path-lengths are localized near the movable wall at a middle-height of the initial column sample. Other particles at the surface moves in a rigid way especially if they were wet and with a low solid density. The “fidelity” of each particle with respect to the nearest neighbours was evaluated allowing to recognize the emergence of clusters of particles and rigid parts, to extract the failure surface and to localize where debonding mechanisms concentrate in the wet case.

Pleural effusion — What do we find in internal medicine

Objective: Pleural effusion is an entity consisting of the excess fluid in the pleural cavity. It is divided into exudate and transudate as a result of local changes in the first or in the case of systemic changes in the case of the second. The indication for performing a thoracentesis is a newly discovered pleural effusion. Nonetheless it is legit not to do it in cases of strongly presumed etiology, or when there is only a small amount of liquid, which makes it technically difficult. In this paper we try to understand what is our reality in the service in terms of how much thoracentesis we do, and what etiology is responsible for its development. Methods: Retrospective analysis of clinical data of patients hospitalized at our infirmary of Internal Medicine, for the period between 1 January and 31 December 2012. We included all patients who had showed the presence of pleural effusion in a diagnosis exam, either X-ray or CT scan. For the ones we did not performed thoracentesis the etiology was given taking into account the clinical evaluation of our patients, the medical history and the positive or negative response to antibiotic therapy and diuretic therapy. Results: It was found that 11.96% of the total patients admitted to the infirmary had some kind of pleural effusion present. Of this 57.7% were males and 42.3% were females. The pleural effusion was bilateral in 56.42%; at the right side in 27.56% and left in 16.02%. Thoracentesis was performed in 9.62% of the patients who had pleural effusions. In this the laboratory testing done was compatible to transudate in 6.7% and to exudate in 93.3%. The etiology of the exudate was in 57.1% of the cases neoplastic; parapneumonic in 14.3%; unknown etiology in 14,3 %; tuberculosis in 7,15%; and traumatic lesion that infected in 7.15%. Of the 90.38% who did not undergo thoracentesis the presumed cause was in 81.6% due to heart failure; in 7.8% due to a known neoplastic disorder; 7.8% parapneumonic; 1.4% due to tuberculosis; 1.4% due to chronic hepatitis; and 1.4% due to sepsis. Of the total of patients with pleural effusion 7.7% died at the infirmary. Conclusion: Pleural effusion is a frequent finding and in most cases it is not required to perform a thoracentesis to know the etiology. The great cause of pleural effusion is heart failure with its various etiologies. We also concluded that in most cases if we are in the presence of a bilateral pleural effusion the cause will be heart failure.

Fabrication of Thin Silicon Sheets for Solar Cells Using the Spin Casting Method

Fabrication of thin silicon sheets via spin casting is investigated for its potential use in a kerf-free wafer production process. To reduce silicon usage and understand the melt spreading process, numerical simulation of spin casting was performed. The simulation showed a specific initial droplet velocity is required to spread small amounts of liquid, and subsequent experiments confirmed this prediction. The increase in initial droplet velocity enabled the reduction in the spreading time and allowed the liquid melt to be spread fully before solidification began. Using a rotating graphite mold, silicon sheets of 100 microm thickness can be produced under optimized experimental conditions.

Nanotribology Application in the Coining Industry (I)—Turn off Stamping Oil Sprayer during Coining

The most common tribological cases involve two solid surfaces repeatedly contacting each other. During coining, however, a pair of dies strikes each blank that has been stamped only once. The requirements of the surface physical and chemical properties for coining are different compared to the common tribological conditions. For example, a low-viscosity stamping oil is used during coining in the United States Mint, as well as other industries. Under coining tonnage this small amount of liquid on die surfaces may promote microcrack propagation. In this case, lubrication does not prolong die life but shortens it. In this work, the lubrication mechanism during coining was studied. A lubricant layer was applied on blank surfaces before coining. Based on the special stamping condition, blank surfaces must meet several tribological requirements. According to these requirements, a new technology was employed and the use of a new lubricant was implemented. As a result, fatigue die life was increased almost three times on high-volume production lines and coin surface quality was improved.

Congenital Hypothyroidism

Congenital Hypothyroidism

Fluidic Optical Switch by Pneumatic Actuation

We proposed a fluidic optical switch based on pneumatic actuation. A small amount of liquid is suspended in a cylinder in vertical position and separates the hollow cylinder into two chambers. A clear pillar with a ball head is fixed in the top chamber. An air channel is used to connect the bottom chamber and a syringe. By controlling the air pressure of the bottom chamber, the liquid can be moved up and down easily. When the liquid is lifted up, the pillar head can enter the liquid and a channel is opened. When the liquid moves down, the liquid can get rid of the pillar and the channel is closed. Our results show that the device can obtain a high optical attenuation (~1178:1) within a reasonable response time (~97 ms). The aperture of the channel is highly circular. The diameter of the channel can be tuned from ~0 to ~4.5 mm. Such an optical switch has potential applications in light shutters, variable optical attenuators, and adaptive irises.

Three Polymorphic CdII Coordination Polymers Obtained from the Solution and Mechanochemical Reactions of 3‐Cyanopentane‐2,4‐dione with CdII Acetate

We previously reported that monomeric and polymeric metal complexes are obtained from solution and mechanochemical reactions of 3-cyano-pentane-2,4-dione (CNacacH) with 3d metal acetates (M = Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)). A common feature found in all complexes was that their structural base is trans-[M(CNacac)(2)]. Here, we report that the reactions of CNacacH with Cd(II) acetate in the solution and solid states afford different coordination polymers composed of trans-[Cd(CNacac)(2)] and cis-[Cd(CNacac)(2)] units, respectively. From a methanol solution containing CNacacH (L) and Cd(OAc)(2)⋅2 H(2)O (M), a coordination polymer (Cd-1) in which trans-[Cd(CNacac)(2)] units are three-dimensionally linked was obtained. In contrast, two different coordination polymers, Cd-2 and Cd-3, were obtained from mechanochemical reactions of CNacacH with Cd(OAc)(2)⋅2 H(2)O at M/L ratios of 1:1 and 1:2, respectively. In Cd-2, cis-[Cd(CNacac)(2)] units are two-dimensionally linked, whereas the units are linked three-dimensionally in Cd-3. Furthermore, Cd-1 and Cd-2 converted to Cd-3 by applying an annealing treatment and grinding with a small amount of liquid, respectively, in spite of the polymeric structures. These phenomena, 1) different structures are formed from solution and mechanochemical reactions, 2) two polymorphs are formed depending on the M/L ratio, and 3) structural transformation of resulting polymeric structures, indicate the usability of mechanochemical method in the syntheses of coordination polymers as well as the peculiar structural flexibility of cadmium-CNacac polymers.