Enhancement Factors in Ozone Absorption Based on the Surface Renewal Model and its Application

Based on the Danckwerts surface renewal model, a simple explicit expression of the enhancement factor in ozone absorption with a first order ozone self-decomposition and parallel second order ozonation reactions has been derived. The results are compared with our previous work based on the film theory. The 2,4-dichlorophenol destruction rate by ozonation is predicted using the enhancement factor model in this paper.

CFD simulation with enhancement factor of sulfur dioxide absorption in the spray scrubber

A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A con- tinuous concentration change of H+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value of pH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.

Stimulated Brillouin Scattering Enhancement Factor Improvement in a 11.6-GHz-Linewidth 1.5-kW Yb-Doped Fiber Amplifier

The stimulated Brillouin scattering （SBS） threshold enhancement factor in a pure white noise linewidth broad- ening Yb-doped fiber amplifier （YDFA） with a short large mode area fiber is theoretically and experimentally studied. We demonstrate a 1064.08nm, 11.6 GHz finewidth, 1.5 k W output power YDFA with an SBS threshold enhancement of -57 （26 W SBS threshold with single frequency seed）. The output beam is near-diffraction lim- ited with a beam quality factor elM2 = 1.15 and a slope efficiency of up to 87%. No SBS or stimulated Raman scattering effects are observed in the whole power range. Further power sealing is limited by the available pump power in our system.

Upregulation of macrophage migration inhibitory factor and calgizzarin by androgen in TM4 mouse Sertoli cells

Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser desorption ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. Results： We found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The ll.3-kDa protein was identified as macrophage migration inhibitory factor （MIF） known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen. Conclusion： MIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.

Limits in Enhancement Factor in Near-Brewster Angle Reflection Pump-Probe Two-Dimensional Infrared Spectroscopy

In this work,we simulated 2D infrared spectroscopy(IR)spectroscopy in both transmission geometry and Brewster-angle reflection geometry.Light dispersion and the leakage of s-polarized light are considered in simulating the enhancement factor of the reflection mode.Our simulation shows that the dispersion in reflection will only alter the 2D IR lineshape slightly and can be corrected.Leaking spolarized light due to imperfectness of IR polarizers in the reflection geometry may limit the enhancement factor,but such limit is above what a typical experiment can reach.In the current experiment,the enhancement factor is mainly limited by the precision of incident angle,for which ordinary rotation stages are probably not adequate enough.Moreover,traditional energy ratio of pump and probe pulses,which is 9:1,may not be ideal and could be changed to 2:1 in the reflection geometry.Considering all the above factors,the enhancement on the order of 1000 is possible in the current experiment.Nevertheless,near-Brewster angle reflection will enhance both the signal and the noise caused by the signal itself,therefore this method only works if the noise is unrelated to the signal,particularly if the noise is caused by the fluctuation in the probe.It cannot improve the signal to noise ratio when the dominate noise is from the signal itself.The theoretical results here agree reasonably well with published experiment results and pave way for realizing even higher enhancement at nearer-Brewster angle.

Overexpression of GATA binding protein 4 and myocyte enhancer factor 2C induces differentiation of mesenchymal stem cells into cardiac-like cells

BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.

Bending Strength of Glass Materials under Strong Dynamic Impact and Its Strain Rate Effects

Based on the structural characteristics of the high-speed loading tester,a four-point bending test device was designed to carry out the four-point bending strength test of glass under the action of static load and different impact velocities,and the formulae for calculating the maximum dynamic stress and strain rate of glass specimens under the action of impact loads were derived.The experimental results show that the bending strength values of the glass under dynamic impact loading are all higher than those under static loading.With the increase of impact speed,the bending strength value of glass specimens generally tends to increase,and the bending strength value increases more obviously when the impact speed exceeds 0.5 m/s or higher.By increasing the impact velocity,higher tensile strain rate of glass specimens can be obtained because the load action time becomes shorter.The bending strength of the glass material increases with its tensile strain rate,and when the tensile strain rate is between 0 and 2 s^(-1),the bending strength of the glass specimen grows more obviously with the strain rate,indicating that the glass bending strength is particularly sensitive to the tensile strain rate in this interval.As the strain rate increases,the number of cracks formed after glass breakage increases significantly,thus requiring more energy to drive the crack formation and expansion,and showing the strain rate effect of bending strength at the macroscopic level.The results of the study can provide a reference for the load bearing and structural design of glass materials under dynamic loading.

Improving Heat Transfer in Parabolic Trough Solar Collectors by Magnetic Nanofluids

A parabolic trough solar collector(PTSC)converts solar radiation into thermal energy.However,low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power plants.Thermal performance of PTSC is enhanced in this study by incorporating magnetic nanoparticles into the working fluid.The circular receiver pipe,with dimensions of 66 mm diameter,2 mm thickness,and 24 m length,is exposed to uniform temperature and velocity conditions.The working fluid,Therminol-66,is supplemented with Fe3O4 magnetic nanoparticles at concentrations ranging from 1%to 4%.The findings demonstrate that the inclusion of nanoparticles increases the convective heat transfer coefficient(HTC)of the PTSC,with higher nanoparticle volume fractions leading to greater heat transfer but increased pressure drop.The thermal enhancement factor(TEF)of the PTSC is positively affected by the volume fraction of nanoparticles,both with and without a magnetic field.Notably,the scenario with a 4%nanoparticle volume fraction and a magnetic field strength of 250 G exhibits the highest TEF,indicating superior thermal performance.These findings offer potential avenues for improving the efficiency of PTSCs in solar thermal plants by introducing magnetic nanoparticles into the working fluid.

Role of visfatin in obesity-induced insulin resistance

The growing worldwide burden of insulin resistance(IR) emphasizes the importance of early identification for improved management.Obesity,particularly visceral obesity,has been a key contributing factor in the development of IR.The obesity-associated chronic inflammatory state contributes to the development of obesity-related comorbidities,including IR.Adipocytokines,which are released by adipose tissue,have been investigated as possible indicators of IR.Visfatin was one of the adipocytokines that attracted attention due to its insulinmimetic activity.It is released from a variety of sources,including visceral fat and macrophages,and it influences glucose metabolism and increases inflammation.The relationship between visfatin and IR in obesity is debatable.As a result,the purpose of this review was to better understand the role of visfatin in glucose homeostasis and to review the literature on the association between visfatin levels and IR,cardiovascular diseases,and renal diseases in obesity.

Protein folding pathology in domestic animals

Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions, of fibrillar microanatomical structures, or secondary fibrillar changes in globular proteins are well known. A special group concerns histologically amorphous deposits, amyloid. The major characteristics of amyloid are: apple green birefringence after Congo red staining of histological sections, and non-branching 7–10 nm thick fibrils on electron microscopy revealing a high content of cross beta pleated sheets. About 25 different types of amyloid have been characterised. In animals, AA-amyloid is the most frequent type. Other types of amyloid in animals represent: AIAPP (in cats), AApoAI, AApoAII, localised AL-amyloid, amyloid in odontogenic or mammary tumors and amyloid in the brain. In old dogs Aβ and in sheep APrPsc-amyloid can be encountered. AA-amyloidosis is a systemic disorder with a precursor in blood, acute phase serum amyloid A (SAA). In chronic inflammatory processes AA-amyloid can be deposited. A rapid crystallization of SAA to amyloid fibrils on small beta-sheeted fragments, the ‘amyloid enhancing factor’ (AEF), is known and the AEF has been shown to penetrate the enteric barrier. Amyloid fibrils can aggregate from various precursor proteins in vitro in particular at acidic pH and when proteolytic fragments are formed. Molecular chaperones influence this process. Tissue data point to amyloid fibrillogenesis in lysosomes and near cell surfaces. A comparison can be made of the fibrillogenesis in prion diseases and in enhanced AA-amyloidosis. In the reactive form, acute phase SAA is the supply of the precursor protein, whereas in the prion diseases, cell membrane proteins form a structural source. Aβ-amyloid in brain tissue of aged dogs showing signs of dementia forms a canine counterpart of senile dementia of the Alzheimer type (ccSDAT) in man. Misfolded proteins remain potential food hazards. Developments concerning prevention of amyloidogenesis and therapy of amyloid deposits are shortly commented.

Research Progress on MEF2B Gene in Human and Animals

Myocyte enhancer factor 2B （MEF2B） gene belongs to myocyte enhancer factor 2 （MEF2） gene family. They are all widely expressed in muscle and nerve tissues of human and animals. MEF2B plays an important role in the growth of muscle, development and differentiation of nerve system and liver fibrosis. This re- view mainly focused on the structural characteristics, tissue distribution, biological functions and research progress of MEF2B gene in human and animals.

Approximate Solution of Homotopic Mapping to Solitary Wave for Generalized Nonlinear KdV System

We study a generalized nonlinear KdV system is studied by using the homotopic mapping method. Firstly, a homotopic mapping transform is constructed; secondly, the suitable initial approximation is selected; then the homotopic mapping is used. The accuracy of the approximate solution for the solitary wave is obtained. From the obtained approximate solution, the homotopic mapping method exhibits a good accuracy.

Heavy-Tailed Statistics in Short-Message Communication

Short-message （SM） is one of the most frequently used communication channels in modern society. Based on the SM communication records provided by some volunteers, we investigate the statistics of SM communication pattern, including the inter-event time distributions between two consecutive short messages and two conversations, and the distribution of message number contained in a complete conversation. In the individual level, the empirical result raises strong evidence that the human activity pattern, exhibiting a heavy-tailed inter-event time distribution, is driven by a non-Poisson process.

Physical Explanation on Designing Three Axes as Different Resolution Indexes from GRACE Satellite-Borne Accelerometer

The GRACE Earth＇s gravitational field complete up to degree and order 120 is recovered based on the same and different three-axis resolution indexes from satellite-borne accelerometer using the improved energy conservation principle. The results show that designing XA1（2） as low-sensitivity axis （3 × 10^-9 m/s^2） of accelerometer and designing YA1（2） and ZA1（2） as high-sensitivity axes （3 × 10^-10 m/s^2） are reasonable. The physical reason why the resolution of XA1（2） is one order of magnitude lower than YA1（2） and ZA1（2） is that non-conservative forces acting on GRACE satellites are mainly decomposed into YA1（2） and ZA1（2） in the orbital plane. Since XA1（2） is not orthogonal accurately to orbital plane during the development of accelerometer, the measurement of XA1（2） can not be thrown off entirely, but be reduced properly.

Enhancement of CO2 Absorption under Taylor Flow in the Presence of Fine Particles

The physical absorption of CO2 in water containing different types of particles was studied in a micro-channel operated under Taylor flow. The maximum enhancement factors of 1.43-2.15 were measured for activated carbon （AcC） particles. The analysis shows that the enhancement effect can be attributed to the shuttle mechanism. Considering the separate contributions of mass transfer from bubble cap and liquid film, a heterogeneous enhance- ment model is developed. According to this model, the enhancement factors Ecap, EFilm and Eov are mainly determined by mass transfer coefficient gL （gL Cap and KL Film）, adsorptive capacity of particles m, and coverage fraction of particles at gas-liquid interface （. With both effects of particle-to-interface adhesion and apparent viscosity included, the model nredicts the enhancement effect of AcC varticles reasonably well.

The Enhancement of CO2 Chemical Absorption by K2CO3 Aqueous Solution in the Presence of Activated Carbon Particles

The enhancement of chemical absorption of CO2 by K2CO3/H2O absorbents in the presence of activated carbon （AC） particles was investigated. The results show that the gas absorption rates can be enhanced significantly in the presence of AC particles, and the maximum enhancement factor 3.7 was observed at low stirring intensities. The enhancement factor increased rapidly with the solid loading during the initial period of absorption and then be- came mild gradually to a maximum value. Both the liquid-solid contact area and the probability of solid particles residing at the gas-liquid interface decreased with the increase of the particle size, leading to a negative effect on the enhancement of mass transfer. The influence of the particles on gas absorption decreased with the reaction rate. The stirring speed changed the interfacial coverage and mass transfer rate on the liquid side and consequently affected the mass transfer between the gas and liquid phases; the enhancement factor decreased with the stirring intensity. A heterogeneous two-zone model was proposed for predicting the enhancement factor and the calculated results agreed well with the experimental data.

Generation of Optical Vortex Using a Spiral Phase Plate Fabricated in Quartz by Direct Laser Writing and Inductively Coupled Plasma Etching

A simple, economical and reliable technique is proposed for fabricating a spiral phase plate （SPP） in a quartz substrate to generate optical vortex with a unit topological charge at the wavelengths of 632.8nm. The spiral phase plate is first formed in the photoresist by direct laser writing lithography and then transferred into the quartz substrate by inductively coupled plasma etching. The performance of the fabricated SPP is verified by using beam intensity distribution, which is in agreement with the theoretical calculation result. The interference measurement suggests that we have succeeded to generate optical vortex with a unit topological charge with the fabricated SPP.

Mass Transfer Enhancement of Gas Absorption by Adding the Dispersed Organic Phases

Mass transfer enhancement of gas absorption by adding a dispersed organic phase has been studied in this work. Various dispersed organic phases （heptanol, octanol, isoamyl alcohol, heptane, octane, and isooctane） were tested respectively in the experiment. According to the theoretical model and experimental data, the overall volumetric mass transfer coefficient and enhancement factor were obtained under different dispersed organic phase volume fraction and stirring speed. The experimental results indicate that gas-liquid mass transfer is enhanced at different level by adding a dispersed organic phase. The best performance of enhancement were achieved with the dispersed organic phase volumetric fraction of 5% and under an intermediate stirring speed of 670 r·min^-1. Among the organic phases tested in the experiment, alcohols show better performance, which gave 20% higher enhance-ment of overall volumetric mass transfer coefficient than adding alkanes.

Viscous Flow over an Unsteady Shrinking Sheet with Mass Transfer

The unsteady viscous flow over a continuously shrinking surface with mass suction is studied. The solution is fortunately an exact solution of the unsteady Navier-Stokes equations. Similarity equations are obtained through the application of similarity transformation techniques. Numerical techniques are used to solve the similarity equations for different values of the mass suction parameters and the unsteadiness parameters. Results show that multiple solutions exist for a certain range of mass suction and unsteadiness parameters. Quite different flow behaviour is observed for an unsteady shrinking sheet from an unsteady stretching sheet.

Mass Transfer Enhancement of Propane Absorption into Dodecane-Water Emulsions

A one-dimensional unsteady heterogeneous parallel mass transfer(ODUHPMT) model was developed for the absorption enhancement of volatile organic compounds(VOC) by the dispersed droplets.An analytical solution for enhancement factor was obtained based on surface renewal theory and the Laplace domain transformation. The absorption rate of propane into water at different stirring speeds with the added micro dodecane droplets was investigated experimentally in a thermostatic stirred tank.The mass transfer flux across the gas-liquid interface and the enhancement factor were measured.The results showed that the dodecane has an obvious enhancement effect on propane absorption into water,the maximum enhancement factor reached 11.The enhancement factor increased with increasing dodecane volume fraction and decreased with increasing stirring speed.The experiment data agreed well with the model predictions and showed high prediction accuracy of ODUHPMT model.