Determining Particle Size and Position in a Coplanar Electrode Setup Using Measured Opacity for Microfluidic Cytometry

Microfluidic impedance flow cytometers enable high-throughput, non-invasive, and label-free detection of single-cells. Cytometers with coplanar electrodes are easy and cheap to fabricate, but are sensitive to positional differences of passing particles, owing to the inhomogeneous electric field. We present a novel particle height compensation method, which employs the dependence of measured electrical opacity on particle height. The measured electrical opacity correlates with the particle height as a result of the constant electrical double layer series capacitance of the electrodes. As an alternative to existing compensation methods, we use only two coplanar electrodes and multi-frequency analysis to determine the particle size of a mixture of 5, 6, and 7 µm polystyrene beads with an accuracy (CV) of 5.8%, 4.0%, and 2.9%, respectively. Additionally, we can predict the bead height with an accuracy of 1.5 µm (8% of channel height) using the measured opacity and we demonstrate its application in flow cytometry with yeast. The use of only two electrodes is of special interest for simplified, easy-to-use chips with a minimum amount of instrumentation and of limited size.

General properties of elmacik fossil beds and Its importance in view of anatolian paleogeography

Tefenni Basin, is located in the southwestern part of Burdur Basin. Elmacık village where paleontological excavations was made, is established at the place where Elmacık stream opens to Tefenni basin. Elmacık fossil beds, were discovered during the geomorphological studies we did in 1997. Lake containing fossil, marsh layers consisting of fillers, are located on the Formation of Burdur. These layers showing different color and texture features, are tilted 10-15 degrees to the east-southeast direction by tectonic movements affecting region. Due to subsidence and rising as a cause of tectonic reasons, this layer series are located at different altitudes. Elmacık fossil beds insitu situation have mostly fossil localities. Secondary fossils are also observed in some layer series. Secondary fossil finds, consists of horn and bone oms belonging to various species lived in earlier periods. Elmacık vertebrate fossil bed, is located between the Neogene fossil beds in Tokmacık town of Isparta province and Özlüce village of Muğla province in south west Anatolia., According to these findings, Elmacık fossil bed shows a bed feature where comparisons can be made in view of the spread and migration of the upper Neogene faunal species. Between 2006 - 2009, excavations were made in five localities in Elmacık fossil beds. Through this excavations, the presence of twelve different macro species were identified in the region, macro proboscidians being in the first place. Among the excavated fossils, defense tooth of South Mamut, has been the largest ivory ever found in Turkey. Palaeontological findings excavated from the Elmacık beds, will be exhibited in a museum of natural history established in the center of Burdur. With new work to be done in the Elmacık fossil beds, withdrawal stages of Burdur Pliocene lake, Pliocene tectonic movements affecting the region and new evidence of Quaternary transition period may also be obtained. Keywords: Elmacık fossil beds, Burdur Formation, South mammoth, the natural history museum.

The Sediment Group Evaluation Index System of Extra High Water-Cut Stage in Waterflooding Oilfield Reservoir

For reserviors which have multiple pay zones, various types and severe heterogeneity, it is China's successful experience of waterflood development to implement layered waterflooding, layered recovery, layered monitoring, and separated layer stimulation and adjustment. So it is worth paying much more attention on how to judge the rationality of layer series division, and only the layer system is reasonably divided can we obtain a higher recovery. In order to make a comprehensive evaluation of the combination of layer series, this paper has screened and analyzed the main indicators affected by the combination of layer series of development applying the principles of multiple correlation analysis, so that we obtain a comprehensive indicator system of layer series combination evaluation, and this system dose play an important role in reasonable layer series division.

Experimental and Theoretical Studies on Effects of Heterogeneity on Channeling in Waterflooding

Water channeling is easy to occur during the process of water flooding in heterogeneous reservoirs. It leads to injected water noneffective cycling, the recovery decreasing and the development cost rising. By means of physical experiments and theoretical analysis, characteristics of water channeling are studied in different heterogeneous reservoirs. The result shows that when permeability contrast is lesser than 5.88, the development performance of reservoirs is similar to homogeneous reservoirs and water cut rises slowly after water breakthrough. If permeability contrast is higher than 5.88, the recovery curve has an inflexion, water cut rises rapidly and water channeling is easy to occur after breakthrough. Therefore, permeability contrast should be lesser than 5.88 in terms of layer series division in interlayer heterogeneous reservoirs. Measures must be taken to avoid water channeling when permeability contrast is higher than 5.88 in inner heterogeneous reservoirs.

Low-Temperature Multistep Topotactic Routes to New Mixed-Valence Perovskites

Multistep topotactic routes are exploited to introduce mixed-valency into mixed-metal oxides at low temperatures (≤ 350°C). A new set of single- and triple-layered perovskites, Na1-x-yCax/2LaTiO4 and Na2-x+yCax/2La2Ti3O10, respectively, has been prepared by a combination of ion exchange and reductive intercalation. The single-layer series are metastable compounds. The magnetic and electronic behavior of the triple-layer titanate is consistent with Anderson localization effects, while those of the single-layer materials are more complex; samples demonstrate “Hurd-like” conductivity and an unusual magnetic response. The details of the synthesis and characterization of these materials are presented and their magnetic and electronic behavior discussed.

Reconstruction of palaeothermal conditions in a passive margin using illite-smectite mixed-layer series (BA1 scientific deep drill-hole, Ardeche, France)

The comparison between measured and predicted smectite percent (%Sm) in an illite-smectite (I-S) mixed-layer series was used to estimate the thermal conditions of diagenesis in the Ardèche sedimentary series. Measurements were performed using the decomposition procedure (Lanson & Besson, 1992) of XRD patterns obtained from oriented preparations (<0.2 μm fractions). Three particle populations were identified: I-S, poorly crystallized illite (PCI), and well crystallized illite (WCI); the %Sm was measured in the I-S population by comparison with calculated XRD patterns using the NEWMOD software (Reynolds, 1985). The theoretical evolution of %Sm with depth obtained with the two first-order kinetic reaction processes described by Velde & Vasseur (1992) was compared to the measured one at Balazuc. The best fit was obtained for the following conditions: 35°C km–1 and between 1500 and 2000 m for the thermal gradient and the eroded piles, respectively. The predicted values for I-S compositions in the 10–0% Sm range are overestimated by the model because the reaction controlling the composition is no longer the dissolution of I-S but the ripening of illitic particles (PCI and WCI).Two zones can be distinguished in the sedimentary series: (1) down to 55 m, the %Sm of I-S particles is highly variable and seems to be controlled by local variations in permeability and chemical composition; (2) down to 550 m, the %Sm of I-S particles is more strictly dependent on the general time-temperature conditions. An anomalously high %Sm value is located in the vicinity of faults at 1669 m due to local change of the water/rock ratio.