Abstract: This paper is about the development of non-invasive heart rate and oxygen saturation in human blood using Altera NIOS II soft-core processor system. In today's world, monitoring oxygen saturation and heart rate is very important in hospitals to keep track of low oxygen levels in blood. We have designed an Embedded System On Peripheral Chip (SOPC) reconfigurable system by interfacing two LED’s of different wavelengths (660 nm/940 nm) with a single photo-detector to measure the absorptions of hemoglobin species at different wavelengths. The implementation of the interface with Finger Probe and Liquid Crystal Display (LCD) was carried out using NIOS II soft-core system running on Altera NANO DE0 board having target as Cyclone IVE. This designed system is used to monitor oxygen saturation in blood and heart rate for different test subjects. The designed NIOS II processor based non-invasive heart rate and oxygen saturation was verified with another Operon Pulse oximeter for 50 measurements on 10 different subjects. It was found that the readings taken were very close to the Operon Pulse oximeter.
Abstract: This paper investigates a possible practical solution for reasonable oxygen supply during the pluripotent stem cells expansion processes, where the stem cells propagate as aggregates in stirred-suspension bioreactors. Low glucose and low oxygen concentrations are preferred for efficient proliferation of pluripotent stem cells. However, strong oxygen limitation, especially inside of cell aggregates, can lead to cell starvation and death. In this research, the oxygen concentration profile inside of stem cell aggregates in a stem cell expansion process was predicted using a modified oxygen diffusion model. This profile can be realized during the stem cells cultivation process by manipulating the oxygen concentration in inlet gas or inlet gas flow. The proposed approach is relatively simple and may be attractive for installation in a real pluripotent stem cell expansion processes.
Abstract: Nanostructured catalysts were successfully prepared
by acidification of diatomite and regeneration of FCC spent catalysts.
The obtained samples were characterized by IR, XRD, SEM, EDX,
MAS-NMR (27Al and 29Si), NH3-TPD and tested in catalytic
pyrolysis of biomass (rice straw). The results showed that the similar
bio-oil yield of 41.4% can be obtained by pyrolysis with catalysts at
450oC as compared to that of the pyrolysis without catalyst at 550oC.
The bio-oil yield reached a maximum of 42.55% at the pyrolysis
temperature of 500oC with catalytic content of 20%. Moreover, by
catalytic pyrolysis, bio-oil quality was better as reflected in higher
ratio of H/C, lower ratio of O/C. This clearly indicated high
application potential of these new nanostructured catalysts in the
production of bio-oil with low oxygenated compounds.
Abstract: Multipotent mesenchymal stromal cells (MSCs)
possess immunomodulatory properties. The effect of MSCs on the
crucial cellular immunity compartment – T-cells is of a special
interest. It is known that MSC tissue niche and expected milieu of
their interaction with T- cells are characterized by low oxygen
concentration, whereas the in vitro experiments usually are carried
out at a much higher ambient oxygen (20%). We firstly evaluated
immunomodulatory effects of MSCs on T-cells at tissue-related
oxygen (5%) after interaction implied cell-to-cell contacts and
paracrine factors only. It turned out that MSCs under reduced oxygen
can effectively suppress the activation and proliferation of PHAstimulated
T-cells and can provoke decrease in the production of
proinflammatory and increase in anti-inflammatory cytokines. In
hypoxia some effects were amplified (inhibition of proliferation, antiinflammatory
cytokine profile shift). This impact was more evident
after direct cell-to-cell interaction; lack of intercellular contacts could
revoke the potentiating effect of hypoxia.
Abstract: Single-phase, high band gap energy Zn0.5Mg0.5O films were grown under oxygen pressure, using pulse laser deposition with a Zn0.5Mg0.5O target. Structural characterization studies revealed that the crystal structures of the ZnX-1MgXO films could be controlled via changes in the oxygen pressure. TEM analysis showed that the thickness of the deposited Zn1-xMgxO thin films was 50–75 nm. As the oxygen pressure increased, we found that one axis of the crystals did not show a very significant increase in the crystallization compared with that observed at low oxygen pressure. The X-ray diffraction peak intensity for the hexagonal-ZnMgO (002) plane increased relative to that for the cubic-ZnMgO (111) plane. The corresponding c-axis of the h-ZnMgO lattice constant increased from 5.141 to 5.148 Å, and the a-axis of the c-ZnMgO lattice constant decreased from 4.255 to 4.250 Å. EDX analysis showed that the Mg content in the mixed-phase ZnMgO films decreased significantly, from 54.25 to 46.96 at.%. As the oxygen pressure was increased from 100 to 150 mTorr, the absorption edge red-shifted from 3.96 to 3.81 eV; however, a film grown at the highest oxygen pressure tested here (200 mTorr).
Abstract: Low oxygen content vanadium powder was
prepared by hydrogenation dehydrogenization (HDH). The
effect of purification treatment on hydrogen absorption kinetics
of dendritic vanadium was tested, and the effects of milling
technique on powder yield and grain size were studied. The
crystal phase, oxygen and nitrgen content, and grain size of
prepared powder were characterized and analyzed by X-ray
diffraction (XRD), oxygen and nitrogen analyzer and grain size
analyzer. The results show that the alkaline cleaning can
improve the hydrogen absorption of vanadium. The yield of
vanadium hydride powder can reach as high as 90% by 4h
ball-milling, The resultant product also have an oxygen content
less than 600μg/g, and the grain size is smaller than 37μm.
Meanwhile, the XRD results show that the phase of hydride
vanadium powder is mainly VH0.81. After a hydrogen
desorption treatment in vacuum at 700Ôäâ, the phase of the
powder converts into V and a little of V2H.
Abstract: Films of pure tin oxide SnO2 and in presence of
antimony atoms (SnO2-Sb) deposited onto glass substrates have
shown a sufficiently high energy gap to be transparent in the visible
region, a high electrical mobility and a carrier concentration which
displays a good electrical conductivity [1]. In this work, the effects of
polycrystalline silicon substrate on the optical properties of pure and
Sb doped tin oxide is investigated.
We used the APCVD (atmospheric pressure chemical vapour
deposition) technique, which is a low-cost and simple technique,
under nitrogen ambient, for growing this material. A series of SnO2
and SnO2-Sb have been deposited onto polycrystalline silicon
substrates with different contents of antimony atoms at the same
conditions of deposition (substrate temperature, flow oxygen,
duration and nitrogen atmosphere of the reactor). The effect of the
substrate in terms of morphology and nonlinear optical properties,
mainly the reflectance, was studied. The reflectance intensity of the
device, compared to the reflectance of tin oxide films deposited
directly on glass substrate, is clearly reduced on the overall
wavelength range. It is obvious that the roughness of the poly-c
silicon plays an important role by improving the reflectance and
hence the optical parameters.
A clear shift in the minimum of the reflectance upon doping level
is observed. This minimum corresponds to strong free carrier
absorption, resulting in different plasma frequency. This effect is
followed by an increase in the reflectance depending of the antimony
doping. Applying the extended Drude theory to the combining
optical and electrical obtained results these effects are discussed.