SURFACE OIL FLOW TECHNIQUE AND LIQUID CRYSTAL THERMOGRAPHY FOR FLOW VISUALIZATION IN IMPULSE WIND TUNNELS

This paper describes flow visualization techniques employing surface oil flow and liquid crystal thermography suitable for use in impulse wind tunnels.High spatial resolution photographs of oil flow patterns and liquid crystal thermograms have been obtained within test times ranging from 7 to 500 ms and have been shown to be very useful for revealing the detailed features of 3-D separated flow.The results from oil flow patterns,liquid crystal thermograms,schlieren photographs and heat flux measurements are shown to be in good agreement.

A ROBUST FLOW CALCULATION TECHNIQUE WITH MULTIPLE FINITE CONTROL VOLUMES

The control volume method gives the forces which act on the system, but not necessarily the wall pressure of the system. The author has made an attempt to develop a control volume method which makes it possible to obtain the wall pressure of the control volume. The 2-D inviscid incompressible steady duct flow is considered. The conservation equations in integral form are discretized for a control volume. The circulation along the control surface is expressed as a nonlinear function of the vertical velocity component at the inlet and is set equal to zero for the inviscid flow. The equation is solved by the Newton method, and the other aerodynamic properties can be obtained. The calculated results have been compared to the experiment and the agreement has been found fairly satisfactory.

Design of axial flaps with color Doppler flow imaging technique for repairing deep wounds of heels

To report the methods and effect of axial pattern flap on lower limb in repairing deep wounds of heels by using color Doppler flow imaging (CDFI) technique so as to solve the ever before problems that the vessel can not be displayed in designing axial flap.Methods Suitable axial flaps on lower limbs were selected according to the character of the wounds.There were 25 flaps including 10 cases of the distal-based sural neurovascular flap,nine medial sole flap and six medial leg flap.All the axial pattern flaps were designed on the basis of traditional design ways before operation;then,CDFI appliance with high resolution was used to examine the starting spot,exterior diameter,trail and length of the flap’s major artery.The flaps were redesigned according to the results of CDFI and transferred to cover the wounds.In the meantime,both the results of operation and examination were compared.Results The major artery’s starting spot,exterior diameter,trail and anatomic layers were displayed clearly,in consistency with the results of operation.The flaps survived completely and recovered well,with perfect appearance,color and arthral function.Conclusion CDFI is a simple,macroscopic and atraumatic method for designing the axial pattern flap on lower limb,can provide more scientific and accurate evidence for preoperative determination of flap transplantation and is worthy of clinical application.10 refs,4 figs,2 tabs.

Void fraction measurement of bubble and slug flow in a small channel using the multivision technique

Using the multivision technique, a new void fraction measurement method was developed for bubble and slug flow in a small channel. The multivision system was developed to obtain images of the two-phase flow in two perpendicular directions. The obtained images were processed--using image segmentation, image subtraction, Canny edge detection, binarization, and hole filling-to extract the phase boundaries and information about the bubble or slug parameters, With the extracted information, a new void fraction measurement model was developed and used to determine the void fraction of the two-phase flow. The proposed method was validated experimentally in horizontal and vertical channels with different inner diameters of 2.1, 2.9, and 4.0 mm, The proposed method of measuring the void fraction has better performance than the methods that use images acquired in only one direction, with a maximum absolute difference between the measured and reference values of less than 6%.

Isolation and identification of CD4^+CD25^+ regulatory T cells in rat

Objective： To establish a stable and high efficient method for collection of CD4^＋CD25^＋ regulatory T cells from rats in vitro. Methods： CD4^＋CD25^＋ regulatory T cells were isolated from the rat splenic cells through two steps by magic cell sorting （MACS） system. The first step was negative selection of CD4^＋T cells by cocktail antibodies and anti-IgG magic microbeads, and the second step was positive selection of CD25^＋T cells by anti-CD25 PE and anti-PE magic microbeads. The purity and viability of separated cells were measured by flow cytometry （FACS） and Trypan blue staining. The suppressive ability of seperated cells on the proliferation of CD4^＋CD25^- T cells was assessed by cell proliferation assay. Results： The purity of negatively enriched CD4^＋ T cells was 79%-87% （83.6%±2.5% ） , and the purity of positively enriched CD4^＋CD25^＋ T cells was 86%- 93% （ 90.2±1.8% ） with the viability of 92%～95% （92.8% ± 3.4% ）. The enriched cells significantly suppressed the proliferation of CD4^＋CD25^- T cells in mixed lymphocyte culture （P 〈 0.05）. Conclusion： An effective method can be established for enrichment of CD4^＋CD25^＋ regulatory T cells in two steps by MACS, with satisfied cell purity, viability and function.

Photoinduced Merging with Copper-or Nickel-Catalyzed 1,4-Cyanoalkylarylation of 1,3-Enynes to Access Multiple Functionalizatized Allenes in Batch and Continuous Flow

A three-component reaction of 1,3-enynes and cyclobutanone oxime esters in the presence of aryl boronic acids or organozinc reagents via the photoredox/copper or photoredox/nickel catalysis has been established.This redox-neutral 1,4-cyanoalkylarylation reaction has demonstrated mild condition,high catalytic reactivity and wide functional group compatibility,allowing access to a variety of functionalized tetra-substituted allene derivatives with high chemo-and regioselectivity.Moreover,using photocatalytic continuous flow technique to promote this process would result in increased yields(70%in flow vs.61%in batch),reduced reaction times(7 min in flow vs.6 h in batch),and easy scale-up(upgrade to gram scale),showcasing its potential as a synthetic platform.