Increase In Capture Efficiency Research Articles

Coupled effect of injection position variation on gas exchange stability of a free-piston engine

Gas exchange fluctuations may lead to operation instability of the free-piston engine (FPE), because the engine has a coupling effect between the gas exchange and the piston motion, which is different from a conventional engine. It is, therefore, important to study the gas exchange instability to ensure the stable operation of the engine. This study focuses the effect of variable piston position when injecting on the gas exchange stability of a looped scavenging FPE, and a systematic full-cycle gas exchange model is presented by developing a dynamic model, a combustion model, and a multidimensional scavenging model. Meanwhile, an iterative method between motion and scavenging is used to solve the model numerically for gas exchange simulation, and the effects of variable piston position when injecting on piston motion, thermodynamic in cylinder, and gas exchange process are studied. The results indicate that retarding injection induces instability of gas exchange duration which first increases and then decreases, and there is an injection position which is most conducive to the increase of capture efficiency of gas exchange, although the scavenging efficiency is lowest under this condition. This result also suggests that more complete exhaust may be achieved by a different injection position.

Microfluidic Acoustic Method for High Yield Extraction of Cell-Free DNA in Low-Volume Plasma Samples.

Cell-free DNA has many applications in clinical medicine, in particular in cancer diagnosis and cancer treatment monitoring. Microfluidic-based solutions could provide solutions for rapid, cheaper, decentralized detection of cell-free tumoral DNA from a simple blood draw, or liquid biopsies, replacing invasive procedures or expensive scans. In this method, we present a simple microfluidic system for the extraction of cell-free DNA from low volume of plasma samples (≤500μL). The technique is suitable for either static or continuous flow systems and can be used as a stand-alone module or integrated within a lab-on-chip system. The system relies on a simple yet highly versatile bubble-based micromixer module whose custom components can be fabricated with a combination of low-cost rapid prototyping techniques or ordered via widely available 3D-printing services. This system is capable of performing cell-free DNA extractions from small volumes of blood plasma with up to a tenfold increase in capture efficiency when compared to control methods.

Experimental Study of Sand Particle Deposition on a Film-Cooled Turbine Blade at Different Gas Temperatures and Angles of Attack

Particle deposition tests were conducted in a turbine deposition facility with an internally staged single-tube combustor to investigate the individual effect of the gas temperature and angle of attack. Sand particles were seeded to the combustor and deposited on a turbine blade with film-cooling holes at temperatures representative of modern engines. Fuel-air ratios were varied from 0.022 to 0.037 to achieve a gas temperature between 1272 and 1668 K. Results show that capture efficiency increased with increasing gas temperature. A dramatic increase in capture efficiency was noted when gas temperature exceeded the threshold. The deposition formed mostly downstream of the film-cooling holes on the pressure surface, while it concentrated on the suction surface at the trailing edge. Deposition tests at angles of attack between 10° and 40° presented changes in both deposition mass and distribution. The capture efficiency increased with the increase in the angle of attack, and simultaneously the growth rate slowed down. On the blade pressure surface, sand deposition was distributed mainly downstream of the film-cooling holes near the trailing edge in the case of the small angle of attack, while it concentrated on the region around the film-cooling holes near the leading edge, resulting in the partial blockage of holes, in the case of the large angle of attack.

Versatile hybrid acoustic micromixer with demonstration of circulating cell-free DNA extraction from sub-ml plasma samples.

Acoustic micromixers have attracted considerable attention in the last years since they can deliver high mixing efficiencies without the need for movable components. However, their adoption in the academic and industrial microfluidics community has been limited, possibly due to the reduced flexibility and accessibility of previous designs since most of them are application-specific and fabricated with techniques that are expensive, not widely available and difficult to integrate with other manufacturing technologies. In this work, we describe a simple, yet highly versatile, bubble-based micromixer module fabricated with a combination of low-cost rapid prototyping techniques. The hybrid approach enables the integration of the module into practically any substrate and the individual control of multiple micromixers embedded within the same monolithic chip. The module can operate under static and continuous flow conditions showing enhanced mixing capabilities compared to similar devices. We show that the system is capable of performing cell-free DNA extractions from small volumes of blood plasma (≤500 μl) with up to a ten-fold increase in capture efficiency when compared to control methods.

A Miniature Gas Sampling Interface with Open Microfluidic Channels: Characterization of Gas-to-Liquid Extraction Efficiency of Volatile Organic Compounds.

Chemosensory protein based olfactory biosensors are expected to play a significant role in next-generation volatile organic compound (VOC) detection systems due to their ultra-high sensitivity and selectivity. As these biosensors can perform most efficiently in aqueous environments, the detection systems need to incorporate a gas sampling interface for gas-to-liquid extraction. This interface should extract the VOCs from the gas phase with high efficiency and transfer them into the liquid containing biosensors to enable subsequent detection. To design such a transfer interface, an understanding of the key parameters influencing the gas-to-liquid extraction efficiency of target VOCs is crucial. This paper reports a gas sampling interface system based on a microfluidic open-channel device for gas-to-liquid extraction. By using this device as a model platform, the key parameters dictating the VOC extraction efficiency were identified. When loaded with 30 μL of capture liquid, the microfluidic device generates a gas-liquid interface area of 3 cm2 without using an interfacial membrane. The pumpless operation based on capillary flow was demonstrated for capture liquid loading and collection. Gas samples spiked with lipophilic model volatiles (hexanal and allyl methyl sulfide) were used for characterization of the VOC extraction efficiency. Decreasing the sampling temperature to 15 °C had a significant impact on increasing capture efficiency, while variation in the gas sampling flow rate had no significant impact in the range between 40–120 mL min−1. This study found more than a 10-fold increase in capture efficiency by chemical modification of the capture liquid with alpha-cyclodextrin. The highest capture efficiency of 30% was demonstrated with gas samples spiked with hexanal to a concentration of 16 ppm (molar proportion). The approach in this study should be useful for further optimisation of miniaturised gas-to-liquid extraction systems and contribute to the design of chemosensory protein-based VOC detection systems.

Abstract P3-01-20: Proof-of-concept of a 4-marker system for improved CTC analysis of metastatic triple-negative breast cancer

Abstract Introduction: Circulating tumor cells (CTCs) represent a potent opportunity to glean important information about in vivo breast cancer biology in a non-invasive fashion. A current limitation to CTC analysis is the inability of positive-selection systems to capture EpCAM-low/negative CTCs, a phenotype that is enriched in the CTCs of metastatic triple negative breast cancers (mTNBCs). This proof-of-concept study aims to increase CTC capture for downstream molecular analysis though the inclusion of additional markers specifically relevant to TNBC. Methods: For inclusion in the analysis, marker candidates were: (1) sufficiently characterized in TNBC, (2) exclusively surface markers to avoid permeabilization, (3) not reported on leukocytes if a cluster of differentiation (CD) nomenclature was associated, and (4) targetable with commercially available antibodies. Cell lines were purchased as part of the TNBC Panel 3 (ATCC) and were characterized as positive or negative across the selected markers by flow cytometry. Capture efficiency of cell lines from culture medium was conducted using antibodies conjugated to magnetic beads in concert with an immunomagnetic detection system developed by the Savran Research Group at Purdue University. Comparisons to EpCAM-only based detection in capture efficiency experiments were completed using Student's t-test. EDTA-anticoagulated blood drawn from normal subjects was assessed for CTCs using the 4-marker capture and parallel 4-marker fluorescent cross-stain. This study was approved by the Institutional Review Board at Indiana University. Results: We assessed surface expression of 4 markers (TROP2, N-Cadherin, EGFR, EpCAM) across 11 TNBC cell lines using flow cytometry. 100% of cell lines were positive for at least 1 of 4 markers in the panel. 7 of 11 cell lines were characterized by EpCAM positivity. The remaining 4 EpCAM-negative cell lines were positive for N-Cadherin, EGFR, or both in the absence of EpCAM. Immunomagnetic capture experiments performed across the 4 EpCAM-negative cell lines revealed a significant increase in capture efficiency yielded by the 4-marker panel as compared to EpCAM-only capture (p=0.0006). Capture efficiency for EpCAM-positive cell lines with the 4-marker panel was equivalent to EpCAM-only. The 4-marker panel was highly specific as CTC assessment of blood samples collected from 5 normal women without cancer yielded 0 positive cells. Discussion: Compared to EpCAM-only based capture, the 4-marker experimental system presented here has potential to enhance CTC analysis by more completely representing the heterogeneity of TNBC. This results in better overall capture efficiency, while still maintaining sufficient specificity. The primary limitation of our study is that in vivo characterization of the system is incomplete. To address this, a clinical protocol for the performance assessment of this method compared to EpCAM-based detection in patients with mTNBC has been initiated at Indiana University and will begin enrolling patients in July 2018. Citation Format: Hancock BA, Chang C-L, Zhong Y, Solzak JP, Chen Y-H, Savran C, Radovich M. Proof-of-concept of a 4-marker system for improved CTC analysis of metastatic triple-negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-01-20.

Versatile exclusion-based sample preparation platform for integrated rare cell isolation and analyte extraction.

Rare cell populations provide a patient-centric tool to monitor disease treatment, response, and resistance. However, understanding rare cells is a complex problem, which requires cell isolation/purification and downstream molecular interrogation - processes challenged by non-target populations, which vary patient-to-patient and change with disease. As such, cell isolation platforms must be amenable to a range of sample types while maintaining high efficiency and purity. The multiplexed technology for automated extraction (mTAE) is a versatile magnetic bead-based isolation platform that facilitates positive, negative, and combinatorial selection with integrated protein staining and nucleic acid isolation. mTAE is validated by isolating circulating tumor cells (CTCs) - a model rare cell population - from breast and prostate cancer patient samples. Negative selection yielded high efficiency capture of CTCs while positive selection yielded higher purity with an average of only 95 contaminant cells captured per milliliter of processed whole blood. With combinatorial selection, an overall increase in capture efficiency was observed, highlighting the potential significance of integrating multiple capture approaches on a single platform. Following capture (and staining), on platform nucleic acid extraction enabled the detection of androgen receptor-related transcripts from CTCs isolated from prostate cancer patients. The flexibility (e.g. negative, positive, combinatorial selection) and capabilities (e.g. isolation, protein staining, and nucleic acid extraction) of mTAE enable users to freely interrogate specific cell populations, a capability required to understand the potential of emerging rare cell populations and readily adapt to the heterogeneity presented across clinical samples.

Laboratory to bench-scale evaluation of an integrated CO2 capture system using a thermostable carbonic anhydrase promoted K2CO3 solvent with low temperature vacuum stripping

An advanced post-combustion CO2 capture process with combined attributes of a thermostable carbonic anhydrase (CA) enzyme catalyst, low-enthalpy K2CO3 solvent, and vacuum stripping utilizing low exergy steam was evaluated from laboratory concept to application performance testing in an integrated 30 standard liters per minute gas flow bench-scale system operated for 500 h. Laboratory concept studies were performed using a wetted wall column to characterize solvent CO2 absorption kinetics and using a recirculating temperature loop to evaluate CA thermo-stability. Wetted wall column tests showed a dramatic 5-fold increase in CO2 mass transfer coefficient when combining 2 g/L CA with aqueous 23.5 wt% K2CO3 solvent. Further increasing the CA concentration resulted in a gradual increase in mass transfer coefficient until a performance plateau was observed beyond a 4 g/L CA dose. Operating temperature had limited impact on CO2 capture over the range 30–50 °C. Surface tension measurements of 23.5 wt% K2CO3 solvent exhibited a gradual decrease with increasing CA concentration. Thermo-stability tests in a temperature cycling loop designed to mimic the temperature swings between absorption and desorption showed that CA longevity could be extended by decreasing the total cycle time spent at high temperature. Parametric tests in the bench-scale unit resulted in a CO2 capture efficiency increase of 4.6-fold when increasing the CA concentration from zero to 2.5 g/L. Capture efficiency increased with higher reboiler duty (i.e. reboiler temperature) and lower absorber temperature. Tests with a 30 °C absorber temperature delivered >90% capture. Variation in solvent flow rate had little impact on capture efficiency because the reaction closely reached equilibrium at the top of the absorber. The integrated bench-scale system operated successfully for an accumulated 500 h under conditions of 40 °C absorber temperature and stripper at 35 kPa pressure with an approximate 77 °C stripper bottom temperature, delivering an average 84% CO2 capture with 23.5 wt% K2CO3-based solvent containing 2.5 g/L CA. Dissolved CA replenishment and conventional process controls were demonstrated as straightforward approaches to maintain system performance of this benign, low-temperature, CA-promoted process for CO2 capture.

Partial coalescence in double (W1/O/W2) emulsions prepared with skimmed milk, polyglycerol polyricinoleate, and different fats

Partial coalescence was studied in double (W1/O/W2) emulsions prepared with skimmed milk, polyglycerol polyricinoleate (PGPR) as lipophilic emulsifier, and different fats. Microstructural and rheological analyses were performed. Encapsulation efficiency (as a parameter of inner water retention) and solid fat content were estimated by differential scanning calorimetry. The presence of PGPR in dispersed lipid phase promoted partial coalescence especially at higher concentration. This promotion of partial coalescence may have been produced by the increase of collision frequency due to protein displacement by PGPR at the outer interface and/or the increase of capture efficiency due to the modification of fat crystals by PGPR. Partial coalescence was also favored when inner water droplets were released as a consequence of an osmotic unbalance between inner and outer aqueous phases. Thus, the addition of glucose in dispersed aqueous phase decreased the partial coalescence degree due to the higher encapsulation efficiency given by the balanced osmotic pressures. With respect to the effect of the employed fat on partial coalescence, the obtained data indicate that the phenomenon was favored at higher solid fat content in lipid phase. Results led to the conclusion that inner osmolality, encapsulation efficiency, and inhibition of partial coalescence were correlated.Practical applications: The originality of this work resides on boarding the subject of partial coalescence in W1/O/W2 emulsions. The studied systems are proposed as potential lipid‐reduced substitutes of dairy creams, with the employment of alternative non‐dairy fats such as low trans vegetable fat. The combined analysis of partial coalescence and encapsulation efficiency allowed studying their reciprocal effects and evaluating the potentiality of the systems for the encapsulation of hydrophilic compounds. The variations of relative osmotic pressures in inner and outer aqueous phases, lipophilic emulsifier concentration, and solid fat content may lead to desirable or undesirable rheological properties depending on the required texture of the food emulsion. The findings of this work could be an important step pointing to control the factors leading to partial coalescence in W1/O/W2 emulsions for food applications.The stability against partial coalescence in W1/O/W2 emulsions containing polyglycerol polyricinoleate (PGPR) and solid fat in lipid phase is linked to the retention of inner water droplets or the encapsulation efficiency of the system. The higher the inner osmolality the higher the encapsulation efficiency; and the higher the encapsulation efficiency the lower the partial coalescence degree. This aggregation of fat globules is attributed to the increase of collision frequency due to protein displacement by PGPR at the outer interface and/or the increase of capture efficiency due to the modification of fat crystals by PGPR.

The Effect of Freestream Turbulence on Deposition for Nozzle Guide Vanes

An evaluation of the effect of freestream turbulence intensity on the rate of deposit accumulation for nozzle guide vanes (NGVs) was performed using the turbine reacting flow rig (TuRFR) accelerated deposition facility. The TuRFR allowed flows up to 1350 K at inlet Mach numbers of 0.1 to be seeded with coal fly ash particulate in order to rapidly evaluate deposit formation on CFM56 NGVs. Hot film and particle image velocimetry (PIV) measurements were taken to assess the freestream turbulence with and without the presence of a grid upstream of the NGVs. It was determined that baseline turbulence levels were approximately half that of the flow exiting typical gas turbine combustors and were reduced by approximately 30% with the grid installed. Deposition tests indicated that the rate of deposition increases as the freestream turbulence is increased, and that this increase depends upon the particle size distribution. For ash with a mass median diameter of 4.63 μm, the increase in capture efficiency was approximately a factor of 1.77, while for ash with a larger median diameter of 6.48 μm, the capture efficiency increased by a factor of 1.84. The increase in capture efficiency is due to the increased diffusion of particles to the vane surface via turbulent diffusion. Based on these results, smaller particles appear to be less susceptible to this mechanism of particle delivery. Overall, the experiments indicate that the reduction of turbulence intensity upstream of NGVs may lead to reduced deposit accumulation, and consequently, increased service life. A computational fluid dynamics (CFD) analysis was performed at turbulence levels equivalent to the experiments to assess the ability of built-in particle tracking models to capture the physics of turbulent diffusion. Impact efficiencies were shown to increase from 21% to 73% as the freestream turbulence was increased from 5.8% to 8.4%. An analysis incorporating the mass of the particles into the impact efficiency resulted in an increase of the mass-based impact efficiency from 17% to 27% with increasing turbulence. Relating these impact efficiencies directly to capture efficiencies, the predicted increase in capture efficiency with higher turbulence is less than that observed in the experiments. In addition, the variation in the impact efficiencies between the two ash sizes was smaller than the capture efficiency difference from experiments. This indicates that the particle tracking models are not capturing all of the relevant physics associated with turbulent diffusion of airborne particles.

Understanding Trapping as a Tool to Manage Pocket Gophers

The pocket gopher is one of the most damaging vertebrate pests in California and throughout much of North American. Many options are available for managing pocket gophers including the use of rodenticides, burrow fumigation, and trapping. Trapping can be time consuming and labor intensive in some situations, but the efficacy of this approach can often offset these negative attributes. As such, we have engaged in several research projects over the last 5 years to increase the utility and effectiveness of trapping as part of an Integrated Pest Management (IPM) program for pocket gopher control. When comparing traps, we found that the Gophinator trap was a more effective trap than the Macabee, particularly when trapping larger pocket gophers. There does not appear to be a substantial benefit to covering trap-sets in most situations, but if trapping when temperatures are high, covering trap-sets may provide a slight increase in capture efficiency. If covering trap-sets, utilizing peanut butter might provide a slight increase in capture success; attractants provide no benefit if using uncovered trap-sets. Trapping was a highly effective technique for managing pocket gopher populations in crop fields. Furthermore, only 3 days were required for novice trappers to become efficient at capturing pocket gophers, although additional experience does increase the rate of capture. Collectively, these results validate the importance of including trapping in an IPM program, and should benefit all individuals who utilize trapping for managing pocket gopher populations.

Simulation of a bubbling fluidized bed process for capturing CO2 from flue gas

We simulated a bubbling bed process capturing CO2 from flue gas. It applied for a laboratory scale process to investigate effects of operating parameters on capture efficiency. The adsorber temperature had a stronger effect than the regenerator temperature. The effect of regenerator temperature was minor for high adsorber temperature. The effect of regenerator temperature decreased to level off for the temperature >250 °C. The capture efficiency was rather dominated by the adsorption reaction than the regeneration reaction. The effect of gas velocity was as appreciable as that of adsorber temperature. The capture efficiency increased with the solids circulation rate since it was ruled by the molar ratio of K to CO2 for solids circulation smaller than the minimum required one (G s, min ). However, it leveled off for solids circulation rate >G s, min . As the ratio of adsorber solids inventory to the total solids inventory (x w1) increased, the capture efficiency increased until x w1=0.705, but decreased for x w1>0.705 because the regeneration time decreased too small. It revealed that the regeneration reaction was faster than the adsorption reaction. Increase of total solids inventory is a good way to get further increase in capture efficiency.

Nanoporous micro-element arrays for particle interception in microfluidic cell separation

The ability to control cell-surface interactions in order to achieve binding of specific cell types is a major challenge for microfluidic immunoaffinity cell capture systems. In the majority of existing systems, the functionalized capture surface is constructed of solid materials, where flow stagnation at the solid-liquid interface is detrimental to the convection of cells to the surface. We study the use of ultra-high porosity (99%) nanoporous micro-posts in microfluidic channels for enhancing interception efficiency of particles in flow. We show using both modelling and experiment that nanoporous posts improve particle interception compared to solid posts through two distinct mechanisms: the increase of direct interception, and the reduction of near-surface hydrodynamic resistance. We provide initial validation that the improvement of interception efficiency also results in an increase in capture efficiency when comparing nanoporous vertically aligned carbon nanotube (VACNT) post arrays with solid PDMS post arrays of the same geometry. Using both bacteria (∼1 μm) and cancer cell lines (∼15 μm) as model systems, we found capture efficiency increases by 6-fold and 4-fold respectively. The combined model and experimental platform presents a new generation of nanoporous microfluidic devices for cell isolation.

Sudden, “Step” Electron Capture by Conjugated Polymers

Data showing significant time-resolution-limited "step" capture of electrons following radiolysis by 7 - 10 ps electron pulses in a series of different length and different concentration conjugated polyfluorene polymers in tetrahydrofuran (THF) are presented. At the highest concentration, ∼48 mM in repeat units for lengths from 20 to 133 fluorenes, ∼30% of the electrons formed during pulse radiolysis were captured in the step, with a constant efficiency per repeat unit. Step capture per repeat unit (q = 6.9 M(-1)) is 60% of the presolvated electron capture efficiency previously reported for biphenyl in THF, giving capture per polymer molecule 12-80 times larger than that for biphenyl at the same concentration. This increase in capture efficiency is large compared to the rate constant per repeat unit for diffusion-limited electron attachment to the same molecules, which is 13% of that of a single unit of fluorene. Plausible mechanisms of this fast capture are explored. It is shown that both capture of quasi-free and localized presolvated electrons can adequately explain the observations. The large yield of radical anions at low concentration of polyfluorene enables observation of subsequent chemistry on the picosecond time scale in these systems, which would otherwise been limited by diffusional attachment to the nanosecond regime.

Affinity and size capture of circulating tumor cells: A platform for increased sensitivity

Abstract Background: The potential clinical value of evaluating circulating tumor cells (CTCs) from blood is clear. CTC analysis can aid in cancer diagnosis, prognosis, and treatment prediction. However, since CTCs are rare, current analysis is limited by low efficiencies. Variability of expression of cell surface antigens by CTCs make capture mechanisms based on antibody affinity less than ideal. We report here data from a CTC platform that combines affinity capture with size filtration capture. Methods: A spiked cell model was used, involving whole EDTA blood spiked with SKBR-3 human breast cancer cells. Two microfluidic chips were analyzed, a standard chip (T7) with constant gap size between posts, and a gradient chip (MA3) with a gap-size gradient between posts starting at 40 μ and decreasing to 12 μ. Chips were coated with either an anti-EpCAM monoclonal antibody or with no Ab. An anti-cytokeratin (CK) Ab in combination with a nuclear specific fluorescent stain on an automated cell imaging platform was used to identify CTCs. Results: 45% of cells were captured by size alone (MA3 with no Ab), 16% of cells were captured by affinity alone (T7 with MAb), and 65% of cells were captured by a combination of antibody affinity and size gradient (MA3 with MAb). This increased capture efficiency has been confirmed in clinical samples from patients with metastatic breast cancer, with a greater than 40% increase in capture efficiency utilizing both mechanisms. Whole blood from healthy donors run through either chip type yielded virtually no CTCs. FACS analysis showed that 75% of cultured SKBR-3 cells express high levels of EpCAM. This expression level will vary, as will, presumably, the relative contributions of the antibody capture mechanism and the size capture mechanism. A “heat map” analysis can demonstrate visually the relative contributions of each and these will be presented. Conclusions: The MA3 microfluidic chip captures CTCs using a combination of affinity and size filtration. This allows for the capture of CTCs with varying expression levels of EpCAM by exploiting the size differential between these CTCs and other blood elements. This dual-capture mechanism may allow for more efficient capture than affinity alone. Further work evaluating this platform in late-stage breast cancer patients is ongoing.

Economical assessment of competitive enhanced limestones for CO 2 capture cycles in power plants

CO 2 capture systems based on the carbonation/calcination loop have gained rapid interest due to promising carbonator CO 2 capture efficiency, low sorbent cost and no flue gases treatment is required before entering the system. These features together result in a competitively low cost CO 2 capture system. Among the key variables that influence the performance of these systems and their integration with power plants, the carbonation conversion of the sorbent and the heat requirement at calciner are the most relevant. Both variables are mainly influenced by CaO/CO 2 ratio and make-up flow of solids. New sorbents are under development to reduce the decay of their carbonation conversion with cycles. The aim of this study is to assess the competitiveness of new limestones with enhanced sorption behaviour applied to carbonation/calcination cycle integrated with a power plant, compared to raw limestone. The existence of an upper limit for the maximum average capture capacity of CaO has been considered. Above this limit, improving sorbent capture capacity does not lead to the corresponding increase in capture efficiency and, thus, reduction of CO 2 avoided cost is not observed. Simulations calculate the maximum price for enhanced sorbents to achieve a reduction in CO 2 removal cost under different process conditions (solid circulation and make-up flow). The present study may be used as an assessment tool of new sorbents to understand what prices would be competitive compare with raw limestone in the CO 2 looping capture systems.

Sticking of protein-coated particles in a shear field

The shear-driven formation of particle doublets at a wall, of latex and emulsion systems, has been studied using a colloidal particle scattering apparatus. In this technique, one particle is fixed on the wall while a second, mobile free particle is made to collide with the fixed particle by the application of the shear field. The effects of pH (in the range 5.5–4.8) and ionic strength (in the range 0.01–0.5 mol dm −3) on the efficiency of irreversible sticking (capture) of the mobile particle to the fixed particle have been studied for systems stabilised by adsorbed films of sodium caseinate, pure α s1-casein or pure β-casein. At low ionic strength (≤0.2 mol dm −3), the efficiency of capture increases with decreasing pH and increasing ionic strength in ways that are consistent with decreasing net charge on the protein and increased screening of the electrostatic repulsion between the particles. The increase in capture efficiency also agrees well with a previously observed increase in viscoelasticity of the corresponding concentrated protein-stabilised emulsions. However, a pronounced drop in the capture efficiency was found at higher ionic strength (0.5 mol dm −3). This effect at high ionic strength, combined with qualitative visual assessment of the behaviour of particles during collisions, conforms to the additional role of tangential interparticle forces in determining the sticking behaviour. It seems that, if the adsorbed protein layer becomes sufficiently thick, even if it has a very low net charge, then particle sticking can be prevented. The sticking phenomenon probably depends on entanglement of the adsorbed layers and on the strength of the protein–protein attractive interactions, as well as on the net particle charge.

Diel variation in availability and vulnerability of fish to a survey trawl

Summary The effect diel variation in availability and vulnerability has on the fish capture process of a groundfish survey trawl was examined from data collected during an experiment measuring fish escapement underneath the footgear. The survey trawl was significantly more efficient at night in capturing American plaice, Hippoglossoides platessoides, and yellowtail flounder, Limanda ferruginea, but no difference was found in catches of Atlantic cod, Gadus morhua. This increase in capture efficiency at night is related to an increase in availability and vulnerability associated with diel variation in light intensity. No evidence of diel vertical migration was found and changes in availability were linked to visual dependent gear avoidance by the fish. Regardless of light conditions, the survey trawl had a very low capture efficiency for juveniles of the three species studied. Escapement of this size group was extremely high during both day and night periods due to a fast towing speed, use of large bobbin gear, and possible mesh selection.

Electrical Stimulation of Fabric Filtration

Calculations have been made of the efficiencies with which single fibers should capture aerosol particles when the fibers are placed in an electric field. A field oriented either parallel or perpendicular to the direction of aerosol flow should increase capture efficiency, but the perpendicular orientation should give a larger increase. These findings based on theory have been confirmed by bench-scale experiments using flat, nonwoven fabric filters. In addition, it has been found that the reduction in pressure drop that accompanies the application of electric fields is greater with the perpen dicular field. Experiments designed to find the optimum location for the electrodes with respect to the filter have shown that the greatest enhancement of performance is obtained when they are located just below the upstream surface of the fabric. Electrical stimulation of fabric filtration was further investigated using a one-hag lahoratory baghouse. With a commercial needled polyester fabric bag, a 4.5-kV potential applied between electrodes threaded into the bag fabric 15 mm apart and parallel to the bag axis reduced penetration about 50% and pressure drop about 45%. A pressure-drop reduction of this magnitude would effect significant reductions in energy consumption concomitant with the considerable increase in capture efficiency.

Hysteria in The Dog

The metastasis of cancer is strongly associated with the spread of circulating tumor cells (CTCs). Based on the microfluidic devices, which offer rapid recovery of CTCs, a number of studies have demonstrated the potential of CTCs as a diagnostic tool. However, not only the insufficient specificity and sensitivity derived from the rarity and heterogeneity of CTCs, but also the high-cost fabrication processes limit the use of CTC-based medical devices in commercial. Here, we present a low-cost fabric sheet layers for CTC isolation, which are composed of polyester monofilament yarns. Fabric sheet layers are easily functionalized with graphene oxide (GO), which is beneficial for improving both sensitivity and specificity. The GO modification to the low-cost fabrics enhances the binding of anti-EpCAM antibodies, resulting in 10–25% increase of capture efficiency compared to the surface without GO (anti-EpCAM antibodies directly onto the fabric sheets), while achieving high purity by isolating only 50–300 leukocytes in 1 mL of human blood. We investigated CTCs in ten human blood samples and successfully isolated 4–42 CTCs/mL from cancer patients, while none of cancerous cells were found among healthy donors. This remarkable results show the feasibility of GO-functionalized fabric sheet layers to be used in various CTC-based clinical applications, with high sensitivity and selectivity.