Abstract: Future space vehicles will require the use of non-toxic, cryogenic propellants, because of the performance advantages over the toxic hypergolic propellants and also because of the environmental and handling concerns. A prototypical capillary flow liquid acquisition device (LAD) for cryogenic propellants was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations with different submersion depths of the LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel, including horizontally and vertically submersions of the LAD channel assembly at normal gravity environment was conducted. Gravity effects on the flow field in LAD channel are inspected and analyzed through comparing the simulations.
Abstract: This study describes a capillary-based device
integrated with the heating and cooling modules for polymerase chain
reaction (PCR). The device consists of the reaction
polytetrafluoroethylene (PTFE) capillary, the aluminum blocks, and is
equipped with two cartridge heaters, a thermoelectric (TE) cooler, a
fan, and some thermocouples for temperature control. The cartridge
heaters are placed into the heating blocks and maintained at two
different temperatures to achieve the denaturation and the extension
step. Some thermocouples inserted into the capillary are used to obtain
the transient temperature profiles of the reaction sample during
thermal cycles. A 483-bp DNA template is amplified successfully in
the designed system and the traditional thermal cycler. This work
should be interesting to persons involved in the high-temperature
based reactions and genomics or cell analysis.
Abstract: Microcirculation is essential for the proper supply of
oxygen and nutritive substances to the biological tissue and the
removal of waste products of metabolism. The determination of
blood flow in the capillaries is therefore of great interest to clinicians.
A comparison has been carried out using the developed non-invasive,
non-contact and whole field laser speckle contrast imaging (LSCI)
based technique and as well as a commercially available laser
Doppler blood flowmeter (LDF) to evaluate blood flow at the finger
tip and elbow and is presented here. The LSCI technique gives more
quantitative information on the velocity of blood when compared to
the perfusion values obtained using the LDF. Measurement of blood
flow in capillaries can be of great interest to clinicians in the
diagnosis of vascular diseases of the upper extremities.
Abstract: Wetting characteristics of reactive (Sn–0.7Cu solder)
and non– reactive (castor oil) wetting of liquids on Cu and Ag plated
Al substrates have been investigated. Solder spreading exhibited
capillary, gravity and viscous regimes. Oils did not exhibit noticeable
spreading regimes. Solder alloy showed better wettability on Ag
coated Al substrate compared to Cu plating. In the case of castor oil,
Cu coated Al substrate exhibited good wettability as compared to Ag
coated Al substrates. The difference in wettability during reactive
wetting of solder and non–reactive wetting of oils is attributed to the
change in the surface energies of Al substrates brought about by the
formation of intermetallic compounds (IMCs).
Abstract: Many applications require surface modification and
micro-structuring of polymers. For these purposes is mainly used
ultraviolet (UV) radiation from excimer lamps or excimer lasers.
However, these sources have a decided disadvantage - degrading the
polymer deep inside due to relatively big radiation penetration depth
which may exceed 100 μm. In contrast, extreme ultraviolet (EUV)
radiation is absorbed in a layer approximately 100 nm thick only. In
this work, the radiation from a discharge-plasma EUV source (with
wavelength 46.9 nm) based on a capillary discharge driver is focused
with a spherical Si/Sc multilayer mirror for surface modification of
PMMA sample or thin gold layer (thickness about 40 nm). It was
found that the focused EUV laser beam is capable by one shot to
ablate PMMA or layer of gold, even if the focus is significantly
influenced by astigmatism.
Abstract: Although water only takes a little percentage in the total mass of soil, it indeed plays an important role to the strength of structure. Moisture transfer can be carried out by many different mechanisms which may involve heat and mass transfer, thermodynamic phase change, and the interplay of various forces such as viscous, buoyancy, and capillary forces. The continuum models are not well suited for describing those phenomena in which the connectivity of the pore space or the fracture network, or that of a fluid phase, plays a major role. However, Lattice Boltzmann methods (LBMs) are especially well suited to simulate flows around complex geometries. Lattice Boltzmann methods were initially invented for solving fluid flows. Recently, fluid with multicomponent and phase change is also included in the equations. By comparing the numerical result with experimental result, the Lattice Boltzmann methods with phase change will be optimized.
Abstract: With the presence of a uniform vertical magnetic field and suspended particles, thermocapillary instability in a horizontal liquid layer is investigated. The resulting eigenvalue is solved by the Galerkin technique for various basic temperature gradients. It is found that the presence of magnetic field always has a stability effect of increasing the critical Marangoni number.
Abstract: In the paper the mathematical model of tumor
growth is considered. New capillary network formation,
which supply cancer cells with the nutrients, is taken into the
account. A formula estimating a tumor growth in connection
with the number of capillaries is obtained.
Abstract: The aim of this study was to screen for
microorganism that able to utilize 3-N-trimethylamino-1-propanol
(homocholine) as a sole source of carbon and nitrogen. The aerobic
degradation of homocholine has been found by a gram-positive
Rhodococcus sp. bacterium isolated from soil. The isolate was
identified as Rhodococcus sp. strain A4 based on the phenotypic
features, physiologic and biochemical characteristics, and
phylogenetic analysis. The cells of the isolated strain grown on both
basal-TMAP and nutrient agar medium displayed elementary
branching mycelia fragmented into irregular rod and coccoid
elements. Comparative 16S rDNA sequencing studies indicated that
the strain A4 falls into the Rhodococcus erythropolis subclade and
forms a monophyletic group with the type-strains of R. opacus, and
R. wratislaviensis. Metabolites analysis by capillary electrophoresis,
fast atom bombardment-mass spectrometry, and gas
chromatography- mass spectrometry, showed trimethylamine (TMA)
as the major metabolite beside β-alanine betaine and
trimethylaminopropionaldehyde. Therefore, the possible degradation
pathway of trimethylamino propanol in the isolated strain is through
consequence oxidation of alcohol group (-OH) to aldehyde (-CHO)
and acid (-COOH), and thereafter the cleavage of β-alanine betaine
C-N bonds yielded trimethylamine and alkyl chain.
Abstract: Micro droplet formation is considered as a growing
emerging area of research due to its wide-range application in
chemistry as well as biology. The mechanism of micro droplet
formation using two immiscible liquids running through a T-junction
has been widely studied.
We believe that the flow of these two immiscible phases can be of
greater important factor that could have an impact on out-flow
hydrodynamic behavior, the droplets generated and the size of the
droplets. In this study, the type of the capillary tubes used also
represents another important factor that can have an impact on the
generation of micro droplets.
The tygon capillary tubing with hydrophilic inner surface doesn't
allow regular out-flows due to the fact that the continuous phase
doesn't adhere to the wall of the capillary inner surface.
Teflon capillary tubing, presents better wettability than tygon
tubing, and allows to obtain steady and regular regimes of out-flow,
and the micro droplets are homogeneoussize.
The size of the droplets is directly dependent on the flows of the
continuous and dispersed phases. Thus, as increasing the flow of the
continuous phase, to flow of the dispersed phase stationary, the size
of the drops decreases. Inversely, while increasing the flow of the
dispersed phase, to flow of the continuous phase stationary, the size
of the droplet increases.
Abstract: This investigation examines the effect of the sintering
temperature curve in manufactured nickel powder capillary structure
(wick) for a loop heat pipe (LHP). The sintering temperature curve is
composed of a region of increasing temperature; a region of constant
temperature and a region of declining temperature. The most important
region is that in which the temperature increases, as an index in the
stage in which the temperature increases. The wick of nickel powder is
manufactured in the stage of fixed sintering temperature and the time
between the stage of constant temperature and the stage of falling
temperature. When the slope of the curve in the region of increasing
temperature is unity (equivalent to 10 °C/min), the structure of the
wick is complete and the heat transfer performance is optimal. The
result of experiment test demonstrates that the heat transfer
performance is optimal at 320W; the minimal total thermal resistance
is approximately 0.18°C/W, and the heat flux is 17W/cm2; the internal
parameters of the wick are an effective pore radius of 3.1 μm, a
permeability of 3.25×10-13m2 and a porosity of 71%.
Abstract: Brain ArterioVenous Malformation (BAVM) is an abnormal tangle of brain blood vessels where arteries shunt directly into veins with no intervening capillary bed which causes high pressure and hemorrhage risk. The success of treatment by embolization in interventional neuroradiology is highly dependent on the accuracy of the vessels visualization. In this paper the performance of clustering techniques on vessel segmentation from 3- D rotational angiography (3DRA) images is investigated and a new technique of segmentation is proposed. This method consists in: preprocessing step of image enhancement, then K-Means (KM), Fuzzy C-Means (FCM) and Expectation Maximization (EM) clustering are used to separate vessel pixels from background and artery pixels from vein pixels when possible. A post processing step of removing false-alarm components is applied before constructing a three-dimensional volume of the vessels. The proposed method was tested on six datasets along with a medical assessment of an expert. Obtained results showed encouraging segmentations.
Abstract: We aimed to investigate how can target and optimize
pulmonary delivery distribution by changing physicochemical
characteristics of instilled liquid.Therefore, we created a new liquids
group:
a. eligible for desired distribution within lung because of
assorted physicochemical characteristics
b. capable of being augmented with a broad range of
chemicals inertly
c. no interference on respiratory function
d. compatible with airway surface liquid
We developed forty types of new liquid,were composed of
Carboxymethylcellulose sodium,Glycerin and different types of
Polysorbates.Viscosity was measured using a Programmable
Rheometer and surface tension by KRUSS Tensiometer.We
subsequently examined the liquids and delivery protocols by simple
and branched glass capillary tube models of airways.Eventually,we
explored pulmonary distribution of liquids being augmented with
technetium-99m in mechanically ventilated rabbits.We used a single
head large field of view gamma camera.Kinematic viscosity between
0.265Stokes and 0.289Stokes,density between 1g/cm3 and 1.5g/cm3
and surface tension between 25dyn/cm and 35dyn/cm were the most
acceptable.
Abstract: In this study, the effect of greywater irrigation on airwater interfacial area is investigated. Several soil column experiments were conducted for different greywater irrigation to develop the pressure-saturation curves. Surface tension was measured for different greywater concentration and fitted for Gibbs adsorption equation. Pressure-saturation curves show that the reduction of capillary rise stops when it reaches its critical micelle concentration (CMC). A simple theory is derived from pressure-saturation curves for calculating air-water interfacial area in porous medium during greywater irrigation by introducing a term 'hydraulic radius' for the pores. This term diminishes any effect of pore shapes on the air-water interfacial area. The air-water interfacial area was calculated using the pressure-saturation curves and found that it decreases with increasing moisture content. But no significant effect was observed on air-water interfacial area for different greywater irrigation. A maximum of 10% variation in interfacial area was observed at the residual saturation zone.
Abstract: Gas condensate Reservoirs show complicated thermodynamic behavior when their pressure reduces to under dew point pressure. Condensate blockage around the producing well cause significant reduction of production rate as well bottom-hole pressure drops below saturation pressure. The main objective of this work was to examine the well test analysis of naturally fractured lean gas condensate reservoir and investigate the effect of condensate formed around the well-bore on behavior of single phase pseudo pressure and its derivative curves. In this work a naturally fractured lean gas condensate reservoir is simulated with compositional simulator. Different sensitivity analysis done on Corry parameters and result of simulator is feed to analytical well testing software. For consideration of these phenomena eighteen compositional models with Capillary number effect are constructed. Matrix relative permeability obeys Corry relative permeability and relative permeability in fracture is linear. Well testing behavior of these models are studied and interpreted. Results show different sensitivity analysis on relative permeability of matrix does not have strong effect on well testing behavior even most part of the matrix around the well is occupied with condensate.