Influence of Hartmann Number on Convective Flow of Maxwell Fluid between Two Hot Parallel Plates through Porous Medium Subject to Arbitrary Shear Stress at the Boundary

Natural convection flow of unsteady Maxwell fluid with the effects of constant magnetic force in the course of a porous media is investigated in this research work. Fluid motion between a channel of parallel plates is tempted by time dependent shear stress applied on one plate. The governing partial differential equations of a model under consideration are transformed into ordinary differential equations by Laplace transform method and then solved for temperature and velocity fields. The obtained results for temperature fields are expressed in terms of complementary error function. The influences of involved parameters likes Hartmann number, Grashf number, Prandlt number and porosity parameter, on temperature and velocity profiles are shown graphically. There is no such result regarding Maxwell fluid in the existing literature.

Bending analysis and control of rolled plate during snake hot rolling

In order to study the bending behavior of aluminum alloy 7050 thick plate during snake hot rolling, several coupled thermo-mechanical finite element(FE) models were established. Effects of different initial thicknesses, pass reductions, speed ratios and offset distances on the bending value of the plate were analyzed. ‘Quasi smooth plate' and optimum offset distance were defined and quasi smooth plate could be acquired by adjusting offset distance, and then bending control equation was fitted. The results show that bending value of the plate as well as the extent of the increase grows with the increase of pass reduction and decrease of initial thickness; the bending value firstly increases and then keeps steady with the ascending speed ratio; the bending value can be reduced by enlarging the offset distance. The optimum offset distance varies for different rolling parameters and it is augmented with the increase of pass reduction and speed ratio and the decrease of initial thickness. A proper offset distance for different rolling parameters can be calculated by the bending control equation and this equation can be a guidance to acquire a quasi smooth plate. The FEM results agree well with experimental results.

Reparation and Performance Testing of Free Radical Photocurable Passivation Film Modified by Titanate Coupling Agent for Hot-plated Aluminum-zinc Steel Plate

To study the effect of free radical photocurable passivation film modified by titanate coupling agent for hot-plated aluminum-zinc plate,trimethylpropane triacrylate(TMPTA)and 2-phenoxyethyl acrylate were used as active diluents,a mixture of modified epoxy acrylate and modified polyester acrylate in a certain proportion was used as an oligomer,2-methyl-1-[4-(methylothyl)benzene]-2-morpholine acetone(907)was used as a free radical photoinitiator,isopropyl thioxanthone(ITX)was used as sensitizer,and bis(dioctyl phosphate acyl)titanate ethyltitanate acrylamide chelate(FD-812)was used as corrosion inhibitor modifier.After UV-curing,the passivation film was characterized by neutral salt spray test,electrochemical testing and other methods.The general performance of the passivation film may meet the requirements of downstream users of hot aluminum-zinc steel plate.The neutral salt spray test,electrochemical testing and microscopic surface morphology analysis of passivation film are in agreement.The introduction of titanate components may effectively promote the photocuring of free radicals.There have been few reports on the titanate coupling which is added to UV-curing coating formula.The titanate coupling agent contains acrylamide groups and terminal amine groups,acrylamide group has oligomer and crosslinking monomer,the terminal tertiary amine groups can provide hydrogen protons,reduce oxygen polymerization,and a phosphating film is formed on the surface of the metal substrate to improve the adhesion and corrosion resistance of the coating.

Study on Thermal Insulation Performance of Cross-Laminated Bamboo Wall

In recent years,bamboo,as a green building material,has attracted more and more attention worldwide.Inspired by the investigation of cross-laminated timber in structural systems,a new engineered cross-laminated bamboo(CLB)consisting of the cross lamination of bamboo scrimber plates is proposed in this paper.To evaluate its potential in structural applications,the thermal insulation performances of the CLB walls and CLB walls with the EPS foam plate were studied and evaluated by the temperature-controlled box-heat flow meter method.Test results indicated that the thermal insulation performance improved with the increase of thickness,but different wall configurations had little effect on the thermal insulation performance under the same thickness of the CLB wall.The thermal insulation performance of EPS-CLB composite wall was much better than that of CLB wall.In addition,a relatively acceptable accuracy of the theoretical calculations was proved.Finally,the influence of different locations of the EPS foam plate on heat transfer coefficient can be neglected as it was studied based on the validated numerical models.

Fluid flow characteristics of single inclined circular jet impingement for ultra-fast cooling

The fluid flow characteristics of the single bunch inclined jet impingement were investigated with different jet flow velocities,nozzle diameters,jet angles and jet-to-target distances for ultra-fast cooling technology.The results show that the peak pressure varying significantly from nearly 0.5 to above 13.4 kPa locates at the stagnation point with different jet diameters,and the radius of impact pressure affected zone is small promoted from 46 to 81 mm in transverse direction,and 50 to 91 mm in longitude direction when the jet flow velocity changes from 5 to 20 m/s.However,the fluid flow velocity is relatively smaller near the stagnation point,and increases gradually along the radius outwards,then declines.There is an obvious anisotropic characteristic that the flow velocity component along the jet direction is about twice of the contrary one where the jet anlge is 60°,jet diameter is 5 mm,jet length is 8 mm and jet height is 50 mm.

Tolerance effects of non-steroidal anti-inflammatory drugs microinjected into central amygdala,periaqueductal grey,and nucleus raphe Possible cellular mechanism

Pain is a sensation related to potential or actual damage in some tissue of the body. The mainstay of medical pain therapy remains drugs that have been around for decades, like non-steroidal anti-inflammatory drugs （NSAIDs）, or opiates. However, adverse effects of opiates, particularly tolerance, limit their clinical use. Several lines of investigations have shown that systemic （intraperitoneal） administration of NSAIDs induces antinociception with some effects of tolerance. In this review, we report that repeated microinjection of NSAIDs analgin, clodifen, ketorolac and xefocam into the central nucleus of amygdala, the midbrain periaqueductal grey matter and nucleus raphe magnus in the following 4 days result in progressively less antinociception compared to the saline control testing in the tail-flick reflex and hot plate latency tests. Hence, tolerance develops to these drugs and cross-tolerance to morphine in male rats. These findings strongly support the suggestion of endogenous opioid involvement in NSAIDs antinociception and tolerance in the descending pain-control system. Moreover, the periaqueductal grey-rostral ventro-medial part of medulla circuit should be viewed as a pain-modulation system. These data are important for human medicine. In particular, cross-tolerance between non-opioid and opioid analgesics should be important in the clinical setting.

Thermomechanical Characterization of a Bio-Sourced Material Based on Clay and Alfa Fibers

Bio-based materials are of great interest owing to their abundance and the immense potential they display as an ideal alternative to widely used industrial construction materials(that directly and indirectly harm the environment).In this scope,an in-depth experimental study is presented here on clay-based materials aimed to enhance their properties through the addition of other bio-based components such as fibers,in the present case alfa fiber.The thermal conductivity and mechanical properties(compressive and flexural tensile strengths)of the composite clay-alfa material are analyzed with the percentage of alfa fiber in the matrix ranging from 0%to 4%.It is concluded that a percentage of alfa fibers between 1%and 2%is the most effective to get the required optimization of thermal and mechanical behavior of this bio-based material.

Study on the breakup length of circular impinging jet

Circular impinging jet, which is widely used in accelerated control cooling （ACC） equipment to accelerate the cooling of hot rolled plates, is subject to breakup, and may result in undesirable cooling effect. Therefore, the jet breakup should be avoided as possible in industrial production. The objective of this study is to find the relation of the processing parameters of the ACC equipment versus the breakup length of jet with weaker turbulence. To obtain quantitative findings, not only relative experimental study but also numerical simulation was carded out. For a weaker turbulent water jet, the breakup length increases with the increase of jet diameter, as well as with the jet velocity; jet diameter has a significant effect on the breakup length for a certain flow rate when compared with jet velocity; finally a suggested correlation of the jet breakup length versus jet Weber number is presented in this study.

Activation of the corticotropin-releasing factor receptor from the basolateral or central amygdala modulates nociception in guinea pigs

Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].

Hot Deformation Behavior of a Novel Ni-Cr-Mo-B Ultra-heavy Plate Steel by Hot Compression Test

Hot deformation behavior of a novel Ni-Cr-Mo-B heavy plate steel was studied by hot compression tests,which were conducted on a Gleeble-3800thermo-mechanical simulator corresponding to the temperature range of850-1 150℃ with the strain rates of 0.01-10s-1 and the true strain of 0.8.The results suggest that the majority of flow curves exhibit a typical dynamic recrystallization（DRX）behavior with an apparent single peak stress followed by agradual fall towards a steady-state stress.Important characteristic parameters of flow behavior as critical stress/strain for initiation of DRX and peak and steady-state stress/strain were derived from curves of strain hardening rate versus stress and stress versus strain,respectively.Material constants of the investigated steel were determined based on Arrhenius-type constitutive equation,and then the peak stress was predicted by the equation with the hot deformation activation energy of 379 139J/mol,and the predicted values agree well with the experimental values.Furthermore,the effect of Zener-Hollomon parameter on the characteristic points of flow curves was studied using the power law relation,and the ratio of critical stress and strain to peak stress and strain were found to be 0.91and0.46,respectively.

Preparation and Hot Corrosion Behavior of a NiCrAlY+AlNiY Composite Coating

In this study, a NiCrAIY ＋ AINiY composite coating was prepared by arc ion plating technique and sub- sequent annealing treatment. Cyclic hot corrosion tests of the composite coating and a reference NiCrAIY coating coated with mixed salts of Na2SO4 ＋ K2SO4 and Na2SO4 ＋ NaC1 were carried out at 700 ℃. The results indicated that the composite coating performed better against the corrosion due to the gradient element distribution in Al-enriched outer layer and Cr-enriched inner layer. The corrosion mechanisms for the two coatings were also discussed.

Hot Corrosion Behavior of a Cr-Modified Aluminide Coating on a Ni-Based Superalloy

A Cr-modified aluminide coating is prepared on a Ni-based superalloy using arc ion plating and subsequent pack cementation aluminizing.Hot corrosion behavior of the Cr-modified aluminide coating exposed to molten Na2SO4/K2SO4（3：1） or Na2SO4/NaCl（3：1） salts at 900 °C in static air are evaluated as well as the aluminide coating.The results indicate that compared with the aluminide coating,the anti-corrosion properties of the Cr-modified aluminide coating in the both salts are improved,which should be attributed to the beneficial effect of the Cr in the coating.The corrosion mechanism of the Cr-modified aluminide coating,especially the role of Cr in the mixture salt corrosion,is discussed.

The Effect of Internal Heat Acupuncture on the Tolerance Time of Plantar Hot Plate and Pain Threshold of Gastrocnemius Muscle in Rats with Chronic Myofascial Pain Syndrome

Objective:To investigate the effect of internal heat acupuncture on the tolerance time of plantar hot plate and the pain threshold of gastrocnemius in rats with chronic myofascial pain syndrome(MPS).Methods:A total of 80 adult Wistar rats were randomly selected to establish chronic MPS rat models,and randomly divided into four groups:control group,acupuncture group,internal heat acupuncture group A,and internal heat acupuncture group B,with 20 rats in each group.The rats in the control group were not given any treatment,and the rats in the acupuncture group were only given acupuncture treatment.The rats in group A were treated with internal heat acupuncture(needle heating up to 42℃),and the rats in group B were treated with internal heat acupuncture(needle heating up to 44℃).The tolerance time of plantar hot plate,the pain threshold of gastrocnemius muscle and the level of tumor necrosis factor-α(TNF-α)were observed and compared before modeling,1 d before treatment,and 1,7 and 14 d after treatment.Results:There were significant differences in hot plate tolerance time,time and interaction among the four groups(P<0.05),as well as in gastrocnemius tenderness threshold,time and interaction among the four groups(P<0.05),and there were also significant differences in TNF-αlevel among the three groups(P>0.05).There were significant differences in the number of electric shocks,time and interaction among the four groups(P<0.05).Conclusion:In contrast to conventional acupuncture treatment,internal heat acupuncture demonstrates greater efficacy in extending the tolerance duration of hot plate exposure and enhancing the pain threshold of the gastrocnemius muscle in rats afflicted with myofascial pain syndrome.Additionally,it accelerates the amelioration of inflammatory markers and motor function.However,it is important to note that the therapeutic impact of internal heat acupuncture may be influenced by its temperature,with 44℃being the most effective in this research.

Influence of hot rolling on microstructure and mechanical characteristics of explosive-welded FSS/CS laminate

The influence of hot rolling on the microstructure and subsequent mechanical characteristics of explosive-welded ferritic stainless steel （FSS）/carbon steel （CS） laminate was investigated. The results indicate that by hot rolling, decarburization layer disappears and a uniform structure is gained in CS side, but ferrite grains and carbides in constituent FSS form an uneven band microstructure which is denser at superficial zone than near the interface. The transmission electron microscopy results indicate that the layers adhering to the interface show typical deformed microstructure features, i.e., stream-like strips and elongated grains in FSS plates, carbide precipitates and bended cementite fragments in CS plates; and high-density dislocations in both plates, With hot rolling, various mechanical strengths and hardness are increased, while the elongation percentage is diminished. Examination of fractographs from tensile tests reveals predominately small dimples for explosive-welded specimens, whereas both big dimples and cleavage fracture for rolled specimens. Stereomicroscopic fractographs taken on shear samples indicate that the surfaces of explosive-welded specimens exhibit uniform deformation, but uneven deformation is displayed for that of rolled specimens. These results indicate that hot rolling is beneficial to improve the strength of explosive-welded FSS/CS laminate but not good for enhancing its plasticity.

Cooling Efficiency of Laminar Cooling System for Plate Mill

Heat transfer was researched from a perspective of the industry application. On the basis of the first law of thermodynamics, the cooling efficiency was deduced from the change of enthalpy inside hot plate. The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail. The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared. The results indicated that the control accuracy of the modified model was increased obviously.

Involvement of connexin 43 in acupuncture analgesia

Background Connexin 43 （Cx43） is one of the major components of human keratinocyte gap junctions. To study whether gap junctional intercellular communication participates in the transfer of acupoint signals and acupuncture analgesia, the expression of Cx43 was studied in Zusanli （ST36） acupoints compared with control non-acupoint regions in rats after acupuncture. In addition, Cx43 heterozygous gene knockout mice were used to further explore the relationship between Cx43 and acupuncture analgesia.Methods The expression of Cx43 was detected by immunohistochemistry, immunoblotting, and RT-PCR for the Cx43 protein and mRNA. The influence of the Cx43 gene knockout on acupuncture analgesia was measured by a hot plate and observing the writhing response on Cx43 heterozygous gene knockout mice. Results Immunohistochemistry showed abundant Cx43 expression in some cells in the skin and subcutaneous tissue of rat ST36 acupoints. The mRNA and protein levels of Cx43 in acupoints were significantly higher than those in the control points in the non-acupuncture group, and even more so after acupuncture. The hot plate and writhing response experiments showed that partial knockout of the Cx43 gene decreased acupuncture analgesia. Conclusion Cx43 expression and acupuncture analgesia showed a positive correlation.

詹氏魟刺粗提物的药理学研究及话性成分的光谱表征(英文)

AIM:Dasyatis jenkinsii is used traditionally to treat inflammatory complaints and arthritis by the fisherman community and local population.The present study was designed to scientifically investigate the traditional practice through the analgesic,anti-inflammatory,and organ toxicity studies and characterization of bioactive compounds of crude extracts of D.jenkinsii.METHOD: Solvent extract of homogenized fresh fish was prepared using petroleum ether and diethyl ether.The chemical and spectral analyses of extracts were carried out using FT-IR and GC-MS.Analgesic and anti-inflammatory activities were assessed by hot plate,tail clip,and carrageenan induced rat paw edema methods.The organ toxicity of each extract was assessed on brain,liver,and kidney of mice.RESULTS:The IR spectrum indicated the presence of aromatic and aliphatic compounds.GC-MS analysis revealed the presence of 1-(4-carboxy)phenylnona-2,5-diene and 3-hydroxymono-glyceryl hydrogen phthalate in the petroleum ether extract and carboxyl serine,dihydrotryptophan,and indolyl carboxylic acid in the diethyl ether extract.Both extracts showed significant analgesic and anti-inflammatory effects in all the methods tested.The vital organs of the test animals were not affected by the crude extracts significantly.CONCLUSIONS:The presence of biologically active compounds in the crude extracts with analgesic and anti-inflammatory properties justifies the traditional knowledge and paves the way for isolation of these compounds for further experimentation.