CFD studies of scraper built in SPA clarifying tank based on mixture solid-liquid two-phase flow model

In the industrial process of producing the strong phosphoric acid(SPA),clarification of the solution is essential to the ultimate product.However,the large viscosity of sediment and the induced interface interaction result in difficulties when the SPA is clarified.CFD numerical methodology was applied to simulate internal flow field and performance of the low speed scraper based on Mixture solidliquid two-phase flow model.Sediment deposition was generated by loading solid particles at the bottom of clarifying vessel.The moving mesh and RNG k-εmodel were used to simulate the rotational turbulent flow in clarifying tank.Variables studied,amongst others,were the scraper rotation speed and the mounting height,which could affect the solid suspension height.Features of flow field and solid volume fraction distribution in computational domain were presented and analyzed.The numerical reports of the scraper torque and velocities of inlet and outlet filed were obtained.It seems the torque value of rotatio-nal axis and particle suspending height augment with an increasing rotating speed.Meanwhile,a high revolving speed is good for the deposition discharge.The particle fraction distribution in meridional surface and horizontal surface at fixed rotation speed were analyzed to determine the corresponding optimal installation height.The simulating results reflect the flow field is marginally stirred by the scraper and proper working parameters are obtained,in which case the comprehensive properties of the scraper and the clarifying tank are superior.

Plotting the Clarifying Curves and Determination of the Specific Amount of Settled Material during the Initial Period to Sedimentation in Stationary Column of Aqueous Suspensions of Solids

The present paper presents an algorithm and a program for plotting the clarifying curves and for determination of the specific amount of settled material during the initial period based on data obtained from sedimentation experiments in stationary column of aqueous suspensions of solids particles with different concentrations. The algorithm and program have been developed for an interactive, rapid and convenient processing of the data obtained from sedimentation experiments in stationary column of aqueous suspensions of solids particles and allow obtaining with accuracy of precise and expressive graphs which characterize the behaviour of aqueous suspensions to sedimentation in stationary column. Sedimentation study of different aqueous suspensions of solids particles in stationary column is of great importance for experimentally determining the important parameters required to design and exploitation clarifiers and sludge thickeners from waste water treatment plants.

CAS Scientists Clarify Causes of Sandstorms

The main causes of the heavysandstorms ravaging north Chinathis spring are abnormal climateand the encroachment ofdesertification, says a CAS reportreleased in Beijing on May 15.

Incisively Understanding and Scientifically Interpreting the Contemporary Chinese Perspective of Human Rights

The report delivered by Xi Jinping, General Secretary of the Communist Party of China (CPC) Central Committee, to the 20th CPC National Congress laid out goals,tasks, and major policies for developing the cause of the Party and the country for the next five years and more, clarified a number of defining, fundamental and strategically significant issues and put forward a series of new ideas, strategies and measures. It is a programmatic document that guides China to build a modern socialist country in all respects and advance toward the Second Centenary Goal.

EXPRESSION OF MIDKINE IN BENIGN, PREMALIGNANT AND MALIGNANT VULVAR TUMORS

OBJECTIVE: To clarify the role of midkine (MK) in vulvar carcinogenesis though examination of its expression in vulvar lesions including vulvar condyloma acuminata (VCA), vulvar intraepithelial neoplasia (VIN) and vulvar squamous cell carcinomas (VSCC), and to analyze the relationship between MK expression and human papilloma virus (HPV) infection. METHODS: Thirty VSCC, 15 VIN and 10 VCA patients were studied by streptavidin-biotin-immunoperoxidase method. MK expression was compared with clinicopathologic features of vulvar tumors. RESULTS: MK was expressed in 26 of 30 VSCC (87%), 3 of 5 VIN III and all VCA samples, whereas no MK expression was detected in the VIN I-II samples or in normal epithelium. The difference of MK expression between VIN III and VSCC was statistically significant (P

A novel wastewater cleaning system for the stone-crushing and sand-making process

The nature of the slurry from the stone-crushing and sand-making processes is analyzed to develop a novel separation process.The process comprises hydro-cyclone separation followed by screening of the fines,clarification,and filtration.Recovering fine sand and clean wastewater for recycle is demonstrated.The +0.045 mm fine sand fraction and à0.045 mm ultra-fine clay in the slurry are separated and recovered.Fine sand that was previously lost and wasted is now recoverable.The cleaned and reused water is as much as 94% of the total.

Intracellular calcium signaling in osteocytes:A mechano-transduction-mechano paradigm

Osteocytes in vivo are embedded in the mineralized extracellular bone matrix,where their cell bodies reside in the lacunae and are interconnected to neighboring osteocytes through numerous intercellular processes.The 3-dimensional（3D）osteocyte network positioning and ability to communicate with other bone cells make osteocytes ideal mechanosensors of bone.Thus the role of osteocyte network and intercellular communication between osteocytes in response to mechanical stimulation may clarify the mechanisms behind normal bone adaptation to mechanical loading.We have been using intracellular calcium([Ca2+]i)as a ubiquitous real-time signaling indicator for studying mechanotransduction in osteocytic network

STRAIN DIFFERENCE IN THE MICRONUCLEUS INDUCTION AMONG DIFFERENT STRAINS OF MICE WITH A SPECIAL REFERENCE TO MS/Ae MOUSE

The micronucleus test with mice has occupi-ed the prime position among in vivo mutage-nicity testing methods because of its simp-licity and reliability.This test detectsclastogens and spindle poisons.

Hepatitis

920691 The determination of serum hepa-titis B virus DNA by polymerase chain rea-ction in hepatitis B patients treated withalpha-interferon. XU. Jianye(徐建业), et al.Centr Lab, Chongqing Cancer Instit, 630030.Chin J Intern Med, 1992; 31(5): 278-280. To clarify the status of HBV in serum

谈谈英语常用修辞(英文)

Figures of speech is widely used in our daily speech and in ourwriting,though it is most often asscciated with poerry.Prose writershave known deeply that figures of speech not only brings freshness andcolor to writing,but also helps to clarify ideas.

Bud endodormancy in deciduous fruit trees:advances and prospects

Bud endodormancy is a complex physiological process that is indispensable for the survival,growth,and development of deciduous perennial plants.The timely release of endodormancy is essential for flowering and fruit production of deciduous fruit trees.A better understanding of the mechanism of endodormancy will be of great help in the artificial regulation of endodormancy to cope with climate change and in creating new cultivars with different chilling requirements.Studies in poplar have clarified the mechanism of vegetative bud endodormancy,but the endodormancy of floral buds in fruit trees needs further study.In this review,we focus on the molecular regulation of endodormancy induction,maintenance and release in floral buds of deciduous fruit trees.We also describe recent advances in quantitative trait loci analysis of chilling requirements in fruit trees.We discuss phytohormones,epigenetic regulation,and the detailed molecular network controlling endodormancy,centered on SHORT VEGETATIVE PHASE(SVP)and Dormancy-associated MADS-box(DAM)genes during endodormancy maintenance and release.Combining previous studies and our observations,we propose a regulatory model for bud endodormancy and offer some perspectives for the future.

Magnetic-Field-Induced Weak Order in Nematic Liquid Crystals Formed by Biaxial Molecules

Nematic liquid crystal system of interacting biaxial particles via dispersion forces is studied.The molecular orienting potential form in a magnetic field is given for the first time.Weakly ordered isotropic phase is treated in the two-particle cluster approximation.Taking account of the molecular biaxiality,it is found that the ratio of the lowest supercooling temperature T^(*)to the nematic-isotropic phase transition temperature TC approaches the observed value,and the validity of the mean field theory is clarified.

Suppressing secondary reactions of coal pyrolysis by reducing pressure and mounting internals in fixed-bed reactor

Pyrolysis of Shenmu coal was performed in fixed-bed reactors indirectly heated by reducing operating pressure and mounting internals in the reactor to explore their synergetic effects on coal pyrolysis. Mounting internals particularly designed greatly improved the heat transfer inside coal bed and raised the yield of tar production.Reducing pressure further facilitated the production of tar through its suppression of secondary reactions occurring in the reactor. The absolute increase in tar yield reached 3.33 wt% in comparison with the pyrolysis in the reactor without internals under atmospheric pressure. The obtained tar yield in the reactor with internals under reduced pressure was even higher than the yield of Gray–King assay. Through experiments in a laboratory fixed bed reactor, it was also clarified that the effect of reducing pressure is related to volatile release rate in pyrolysis. It did not obviously vary tar yield at pyrolysis temperatures below 600 ℃, while the effect was evident at 650 and 700 ℃ but became limited again above 800 ℃. Under reduced pressure the produced tar contained more aliphatics and phenols but less aromatics.

Evaluation and improvement of wastewater treatment plant performance using BioWin

In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.

A clash of fundamental assumptions:Can/should we measure physical literacy?

The special issue of the Journal of Teaching in Physical Education (JTPE)~1 on physical literacy (PL) has provided much needed information about measuring and assessing student learning in terms of the well-defined and yet abstract concept.Multiple authors have elaborated from diverse educational and psychometric perspectives on the development of the construct,the measurement model,and the assessment of the construct.In this attempt,many issues associated with the conception of PL were clarified and insightful information and arguments were brought forward.In this regard,the special issue has moved our understanding of the concept one step further.More importantly,it points to a possibility to actualize the teaching of the concept in physical education (PE).

The Biden Administration’s Indo-Pacific Strategy and Its Impact on China

Since entering the White House,Biden has placed the Indo-Pacific region at the center of US global strategy,advancing the vision and strategic goals of an Indo-Pacific order in diplomatic,economic,military,and other dimensions.The Indo-Pacific Strategy of the United States,released by the Biden administration in February 2022,further clarified the strategic goals and recent policy measures of the US in the region.

The role of dendritic cells in the immunomodulation to implanted biomaterials

Considering the substantial role played by dendritic cells(DCs) in the immune system to bridge innate and adaptive immunity,studies on DC-mediated immunity toward biomaterials principally center on their adjuvant effects in facilitating the adaptive immunity of codelivered antigens. However, the effect of the intrinsic properties of biomaterials on dendritic cells has not been clarified. Recently, researchers have begun to investigate and found that biomaterials that are nonadjuvant could also regulate the immune function of DCs and thus affect subsequent tissue regeneration. In the case of proteins adsorbed onto biomaterial surfaces,their intrinsic properties can direct their orientation and conformation, forming “biomaterial-associated molecular patterns(BAMPs)”. Thus, in this review, we focused on the intrinsic physiochemical properties of biomaterials in the absence of antigens that affect DC immune function and summarized the underlying signaling pathways. Moreover, we preliminarily clarified the specific composition of BAMPs and the interplay between some key molecules and DCs, such as heat shock proteins(HSPs) and high mobility group box 1(HMGB1). This review provides a new direction for future biomaterial design, through which modulation of host immune responses is applicable to tissue engineering and immunotherapy.

A systematical review of traditional Ayurvedic and morden medical perspectives on Ghrita (clarified butter): a boon or bane

Background:For long dietary guidelines,it is recommended to avoid foods rich in saturated fatlike Ghrita,also named clarified butter or ghee,which is considered as the culprit of cardiovascular diseases,diabetes,stroke,etc.Contradictory to the modern medical science,Ayurveda advocated for numerous benefits of the usage of Ghrita in the judicious manner.This paper systematically reviews and analyses the scientific researches that carried out on the benefits and harms associated with the usage of Ghrita.Methods and Findings:A search over the various search engines like Pubmed,Google was made.The relevant articles and chapters from books retrieved in English language were saved to a folder and analysed for their utility relevant to the topic and the matter was presented in a systematic manner.Results:Ghrita consisted various fats(saturated,monosaturated and polyunsaturated),fatty acids,minerals,vitamins etc.And the composition of Ghrita varies along with the method of preparation.Scientific researches carried out on Ghrita plain as well as medicated have reported about the depressant effects of medicated Ghrita in gross behavioural tests,potentiated phentobarbitone sleeping time,analgesic effect and stimulatory effect on cognition.Further,studies conducted to evaluate the effect of Ghrita on the serum lipid levels showed a dose dependant decrease in the total cholesterol,low density lipoproteins,and very low density lipoproteins.Ghrita was also reported to have wound healing activity.Conclusion:The results of the study suggest the beneficial effects of plain as well as medicated Ghrita on the various components of health and break the myth associated to the exclusion of Ghrita in diet.These researches also substantiate the claims made by the classical texts of Ayurveda.

Is it possible to develop a cerebellar reserve?

The concept of neural plasticity accounts for the now well clarified brain ability to react to internal and external stimuli by transforming its structure and function.The translation of whatever experience in specific electrical signals that run through our neural networks induces a number of plastic changes at both functional and structural levels.

Study on the Relation Bet ween Magnetic Moment and Charge Transfer of Metallic Glasses By LCAO-X_(α) Method

The calculations of the clusters,T_(27) and T_(27)B_(7)(T=Fe,Co and Ni),modelling metallic glasses have been performed using the quantum chemical linear combination of atomic orbitals(LCAO)-X_(α) method.The argument about the relation between magnetic moment and charge transfer has been clarified based on the calculated results.