Small-scale fire tests in the underwater tunnel section model with new sidewall smoke extraction

The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the tunnel has a new smoke exhaust system that combines a horizontal smoke exhaust cross section at the top and sidewall smoke exhaust holes.In order to evaluate the potential fire hazards of this type of tunnel,a 1:30 tunnel model was established and 140 smallscale experiments on underwater tunnel fires were conducted.By changing the fire power,fire location,and fan operation mode,different scenarios of submarine immersed tunnel fire were simulated and the related key parameters such as fire smoke diffusion behavior and smoke temperature distribution were studied.On this basis,the optimal smoke control strategy was proposed for different fire scenarios.The research results indicate that the new smoke exhaust system can fully utilize the smoke flow characteristics,significantly improve smoke exhaust efficiency,and increase available evacuation time,thus further enhancing the fire safety of super large cross-section subsea tunnels.

A state-of-the-art review of automated extraction of rock mass discontinuity characteristics using three-dimensional surface models

In the last two decades,significant research has been conducted in the field of automated extraction of rock mass discontinuity characteristics from three-dimensional(3D)models.This provides several methodologies for acquiring discontinuity measurements from 3D models,such as point clouds generated using laser scanning or photogrammetry.However,even with numerous automated and semiautomated methods presented in the literature,there is not one single method that can automatically characterize discontinuities accurately in a minimum of time.In this paper,we critically review all the existing methods proposed in the literature for the extraction of discontinuity characteristics such as joint sets and orientations,persistence,joint spacing,roughness and block size using point clouds,digital elevation maps,or meshes.As a result of this review,we identify the strengths and drawbacks of each method used for extracting those characteristics.We found that the approaches based on voxels and region growing are superior in extracting joint planes from 3D point clouds.Normal tensor voting with trace growth algorithm is a robust method for measuring joint trace length from 3D meshes.Spacing is estimated by calculating the perpendicular distance between joint planes.Several independent roughness indices are presented to quantify roughness from 3D surface models,but there is a need to incorporate these indices into automated methodologies.There is a lack of efficient algorithms for direct computation of block size from 3D rock mass surface models.

Optimization of Compound Coptis Ointment Extraction through the Integration of Pharmacodynamic Indices and Orthogonal Test

[Objectives]To determine the optimal reflux extraction process conditions for Compound Coptis Ointment.[Methods]The study employed the orthogonal experimental design method and drug-sensitive disc agar diffusion method to evaluate the extraction rate,berberine hydrochloride content,and bacteriostatic ring diameter of the extract as comprehensive indices,and optimized the extraction process conditions of Compound Coptis Ointment using ethanol reflux.[Results]Based on the results of comprehensive indices,the optimal reflux extraction conditions for Compound Coptis Ointment were determined to be soaking in 1.5 times the amount of 70%ethanol for 2 h,followed by two extractions with 6 times the amount of 70%ethanol for 1 h each time.Three verification tests were conducted under the optimal process conditions.The yield of the extract was 28.32%±0.53%,the content of berberine hydrochloride was 4.68%±0.45%,and the diameter of the bacteriostatic ring was(2.5±0.2)cm.[Conclusions]The extract had higher drug content and exhibited better antibacterial effects.The optimized extraction process is simple,stable,and reliable,and can be effectively used to optimize the extraction process of Compound Coptis Ointment.

Three-Dimensional Model Test for Port Engineering with Multi-Directional Waves

-The necessity of using irregular waves, especially multi- directional waves to conduct three-dimensional model tests for port engineering and the test method are described in this paper through an example of model test for a port. The test results show that a deep navigation channel has a large effect on the waves in front of the breakwater near the port entrance and on the wave condition in the port.

Research advances in enhanced coal seam gas extraction by controllable shock wave fracturing

With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low cost.In order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be studied.In this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are provided.Based on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating wire.During the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam.The stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks being.The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas extraction.Under the influence of ground stress,the crack propagation in coal seam will be restrained.The difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced cracks.The permeability enhancement effect of CSW is affected by the breakage degree of coal seam.The shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability enhancement.When arranging two adjacent boreholes for CSW permeability enhancement test,the spacing of boreholes should not be too close,which may lead to negative pressure mutual pulling in the early stage of drainage.At present,the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.

Acute Toxicity of Jinchuan Formula Plum Wine Extract and Its Protective Effect on Mice with Liver Injury

[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.

VISUALIZATION OF THREE-DIMENSIONAL DATA FIELD AND ITS APPLICATION IN MACHINE TESTING

In order to realize visualization of three-dimensional data field （TDDF） in instrument, two methods of visualization of TDDF and the usual manner of quick graphic and image processing are analyzed. And how to use OpenGL technique and the characteristic of analyzed data to construct a TDDF, the ways of reality processing and interactive processing are described. Then the medium geometric element and a related realistic model are constructed by means of the first algorithm. Models obtained for attaching the third dimension in three-dimensional data field are presented. An example for TDDF realization of machine measuring is provided. The analysis of resultant graphic indicates that the three-dimensional graphics built by the method developed is featured by good reality, fast processing and strong interaction

The pilot test of Pt-Pd and Pt-Rh feeds extracted and separated with a new sulfoxide extractant

Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant （MSO） were studied in the paper. The pilot test results showed that the percentage extractions are more than 99% for platinum and palladium in Pt-Pd feed, and the percentage strippings are 100% and 99.2% with HCl and ammonia, respectively. The ratio of palladium to platinum is 0.0016 in stripping platinum solution, and the ratio of platinum to palladium is 0.0020 in stripping palladium solution. The percentage extraction of platinum is 99% in Pt-Rh feed, and the percentage stripping is 100%. The ratio of rhodium to platinum is 0.0002 in stripping platinum solution. Therefore, platinum, palladium, and rhodium feeds are separated effectively with MSO.

Predicting the Dynamic Behavior of Asphalt Concrete Using Three-dimensional Discrete Element Method

A user-defined three-dimensional （3D） discrete element model was presented to predict the dynamic modulus and phase angle of asphalt concrete （AC）. The 3D discrete element method （DEM） model of AC was constructed employing a user-defined computer program developed using the ＂Fish＂ language in PFC3D. Important microstructural features of AC were modeled, including aggregate gradation, air voids and mastic. The irregular shape of aggregate particle was modeled using a clump of spheres. The developed model was validated through comparing with experimental measurements and then used to simulate the cyclic uniaxial compression test, based on which the dynamic modulus and phase angle were calculated from the output stress- strain relationship. The effects of air void content, aggregate stiffness and volumetric fraction on AC modulus were further investigated. The experimental results show that the 3D DEM model is able to accurately predict both dynamic modulus and phase angle of AC across a range of temperature and loading frequencies. The user- defined 3D model also demonstrated significant improvement over the general existing two-dimensional models.

A generalized three-dimensional failure criterion for rock masses

The smooth convex generalized failure function, which represents 1/6 part of envelope in tile deviatoric plane, is proposed. The proposed function relies on four shape parameters （L, a, b and c）, in which two parameters （a and b） are dependent on the others. The parameter Ls is called extension ratio. The proposed failure function could be incorporated with any two-dimensional （2D） failure criteria to make it a three-dimensional （3D） version. In this paper, a mathematical formulation for incorporation of Hoek-Brown failure criterion with the proposed function is presented. The Hoek-Brown failure criterion is the most suited 2D failure criterion tbr geomaterials. Two types of analyses for best-fitting solution of published true tri-axial test data were made by considering （1） constant extension ratio and （2） variable extension ratio. The shape and strength parameters for different types of rocks have been determined by best-fitting the published true tri-axial test data for both the analyses. It is observed from the best-fitting solution by considering uniform extension ratio （L~） that shape constants have a correlation with Hoek-Brown strength parameters. Thus, only two parameters （c~. and m） are needed for representing the 3D failure criterion for intact rock. The statistical expression between shape and Hoek-Brown strength parameters is given. In the second analysis, when considering varying extension ratio, another parameterfis introduced. The modified extension ratio is related tofand extension ratio. The results at minimum mean misfit for all the nine rocks indicate that the range off varies from 0.7 to 1.0. It is found that mean misfit by considering varying extension ratio is lower than that in the first analysis. But it requires three parameters. A statistical expression betweenfand Hoek-Brown strength parameters has been established. Though coefficient of correlation is not reasonable, we may eliminate it as an extra parameter. At the end of the paper, a methodology has also been given for its application to isotropic jointed rock mass, so that it can be implemented in a numerical code for stability analysis of jointed rock mass structures.

Optimization of Extraction Process of Prunellae Spica Compound by Orthogonal Test

[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.

Optimization of Extraction Process of Zihua Qinghuo Capsule by Orthogonal Test

With quercetin content and yield of dry extract as investigation indices, three factors, amount of water added, decoction time and decoction times were investigated by an orthogonal test, so as to select the optimal water extraction process for Zihua Qinghuo Capsule. The determined extraction process was adding 8 times of water in five herbs including Viola philippica and decocting for 2 times, 1.5 h each time. Pilot scale test demonstrated that the selected process is stable and feasible, and could provide reliable reference for practical production.

Numerical study on wave loads and motions of two ships advancing in waves by using three-dimensional translating-pulsating source

A frequency domain analysis method based on the three-dimensional translating-pulsating （3DTP） source Green function is developed to investigate wave loads and free motions of two ships advancing on parallel course in waves. Two experiments are carried out respectively to mea- sure the wave loads and the free motions for a pair of side-by- side arranged ship models advancing with an identical speed in head regular waves. For comparison, each model is also tested alone. Predictions obtained by the present solution are found in favorable agreement with the model tests and are more accurate than the traditional method based on the three dimensional pulsating （3DP） source Green function. Numer- ical resonances and peak shift can be found in the 3DP pre- dictions, which result from the wave energy trapped in the gap between two ships and the extremely inhomogeneous wave load distribution on each hull. However, they can be eliminated by 3DTP, in which the speed affects the free sur- face and most of the wave energy can be escaped from the gap. Both the experiment and the present prediction show that hydrodynamic interaction effects on wave loads and free motions are significant. The present solver may serve as a validated tool to predict wave loads and motions of two ves- sels under replenishment at sea, and may help to evaluate the hydrodynamic interaction effects on the ships safety in replenishment operation.

Evaluation of antidepressant activity of methanolic and hydroalcoholic extracts of Acorus calamus L.rhizome through tail suspension test and forced swimming test of mice

Objective:Acorus calamus(AC)L.(Araceae)is an annual semi-aquatic and aromatic plant found in Europe,North America and Asia.Its rhizomes are often used by Native Americans,Americans,and Chinese as well as by other cultures.Ethnobotanical studies and documents have shown their use in various disease treatments,such as insomnia,mental disorders,diabetes mellitus,epilepsy,inflammation,asthma,neuropathic pain,and diarrhea.In this study,the antidepressant activity of methanolic and hydroalcoholic extracts of the AC rhizome part in mice was investigated.Methods:Three doses of methanolic extract of AC rhizome(MEACR)(25,50 and 100 mg/kg b.wt),three doses of hydroalcoholic extract of AC rhizome(HAACR)(100,200 and 400 mg/kg b.wt),and standards(imipramine,15 mg/kg b.wt and fluoxetine,20 mg/kg b.wt)was daily oral administration to the mice for consecutive 14 days.The extract effect on the immobility time was monitored by a tail suspension test(TST)and a forced swimming test(FST).Monoamine oxidase(MAO)levels were also analyzed using standard methods.Results:The optimum antidepressant activity was viewed at 100 mg/kg b.wt of MEACR extract and400 mg/kg b.wt of HAACR extract with 23.82%and 20.59%immobility period reduction,respectively.Besides,the extracts weakened the FST-induced elevation of MAO activity significantly and returned to near-normal levels of neurotransmitters in the brain.100 mg/kg b.wt or above of MEACR extract significantly prevented the MAO-A and MAO-B activities in mice brain at a dose-dependent fashion.But,just 400 mg/kg b.wt of HAACR extract prevented the activity of MAO-A and MAO-B.Fluoxetine and imipramine showed a tendency to prevent the activity of MAO-A and MAO-B.Conclusion:This study suggests that AC rhizome extract mediated antidepressant activity by modulating the central neurochemical and hypothalamic-pituitary-adrenal(HPA)axis in response to FST and TSTinduced stress.Therefore,AC rhizome extract can be used as a valuable plant supplement to treat depressive disorders.

Three-dimensional experimental study of loose top-coal drawing law for longwall top-coal caving mining technology

Based on the loose medium flow field theory, the loose top-coal drawing law of longwall top-coal caving（LTCC） mining technology is studied by using self-developed three-dimensional（3D） test device. The loose top-coal drawing test with shields and the controlled test without shields are performed in the condition without any boundary effect. Test results show that shields will cause reduction in drawing volume of coal in the LTCC mining. The deflection phenomenon of drawing body is also observed in the controlled test, which is verified that the deflection of drawing body is caused by shield. It is found that the deflection angle decreases with increasing caving height, with the maximum value of atailand the minimum value of 0. In addition, the formula to calculate the drawing volume is proposed subsequently.The deflection of drawing body is numerically simulated using particle flow code PFC3 Dand the proposed formula to calculate drawing volume in LTCC is also verified.

Development and Test of Hydrostatic Extraction Scheme in Spectral Model

The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational instability may occur for high vertical resolution versions if the stratification parameter C0 taken as a constant. In this paper, the possible cause leading to the instability is discussed and an improved scheme presented where C0 is generalized to be a function of both height and latitudes. Hence the reference atmosphere gets closer to the real atmosphere and the temperature deviation field to be expanded becomes smoother everywhere. Test by real case forecasts shows good computational stability of the new scheme and better prediction performance than-usual schemes of spectral model.

Application of NaHCO_3/ DTPA Extractant-ICP Spectrometry Technique in Soil Test for Availability of Nutrients and Heavy Metals

Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.

Field load testing of copper extraction aeration pipes under simulated high heap pile

Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.

Swelling/extraction test of Russian reservoir heavy oil by liquid carbon dioxide

The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from Russia. The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%. When the concentration of carbon dioxide was higher than 26%, the volume of the heavy phase decreased, and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil. When the concentration of carbon dioxide in the mixture was 26%, the effect of viscosity reducing to the heavy phase was the strongest. The density of the light and heavy phases, volume factor, and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture. The best concentration of carbon dioxide in the mixture was 26%, when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest. When the concentration of carbon dioxide in the mixture was between 10% and 26%, the volume of the light phase was the smallest and the oil displacement effect was the best.

Inhibition of mammalian target of rapamycin induces phenotypic reversion in three-dimensional cultures of malignant breast epithelial cells

Inhibition of mammalian target of rapamycin (m- TOR) is a potential method for cancer treatment. Effects of rapamycin (RAP) on the reversion of malignant breast epithelial cells were investigated on three-dimensional (3D) basement membrane extract (BME) cultures. Through continuous exposure to 20 nM of RAP, cell colony size was significantly reduced in 3D BME cultures of malignant breast epithelial cells, while normal cell colony size appeared unaffected. In unfixed 3D BME cultures of normal and RAP-treated malignant breast epithelial cells, the presence of luminal cell death was confirmed by ethidium bromide and propidium iodide labeling. Increased structural organization was observed by im- munofluorescence staining of F-actin and β-catenin in RAP-treated malignant breast epithelial cells. In monolayer cultures of normal and malignant breast epithelial cells, continuous exposure to 20 nM of RAP increased caspase 3/7 activity and decreased proliferation. Reverse transcriptase polymerase ch- ain reaction (RT-PCR) array analysis indicated a fold increase in the expression of a number of proteins related to polarity, cell-cell adhesion, and cell-matrix adhesion in the presence of RAP. Our data showed that phenotypic reversion of malignancy can be ach- ieved through RAP exposure on 3D BME cultures. This 3D BME culture system will provide correct microenvironments for observing the effects of other mTOR inhibitors on phenotypic reversion of malignant breast epithelial cells.