Microstructure studies of air-plasma-spray-deposited CoNiCrAlY coatings before and after thermal cyclic loading for high-temperature application

In the present study, bond-coats for thermal barrier coatings were deposited via air plasma spraying（APS） techniques onto Inconel 800 and Hastelloy C-276 alloy substrates. Scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, X-ray diffraction（XRD）, and atomic force microscopy（AFM） were used to investigate the phases and microstructure of the as-sprayed, APS-deposited Co Ni Cr Al Y bond-coatings. The aim of this work was to study the suitability of the bond-coat materials for high temperature applications. Confirmation of nanoscale grains of the γ/γ′-phase was obtained by TEM, high-resolution TEM, and AFM. We concluded that these changes result from the plastic deformation of the bond-coat during the deposition, resulting in Co Ni Cr Al Y bond-coatings with excellent thermal cyclic resistance suitable for use in high-temperature applications. Cyclic oxidative stability was observed to also depend on the underlying metallic alloy substrate.

Epidemiological Aspects of Diabetic Retinopathy at the Center of the Application of the Diploma of Specialised Studies in Ophthalmology (Cadeso)/Donka-Conakry

Purpose: The authors analyzed the epidemiological and clinical aspects of diabetic retinopathy at the Center for the Application of the Specialized Studies Diploma in Ophthalmology, Gamal Abdel Nasser University (CHU/ Donka) Conakry. Diabetic retinopathy (eye damage: eye and retina) is a serious complication of diabetes that affects 50% of type 2 diabetic patients. The eyes are particularly sensitive to damage to a small vessel. Diabetic retinopathy (DR) is the retinal localization of diabetic micro angiopathy resulting in impaired blood flow in the affected territories, the consequences of which will determine the clinical manifestations of the disease. DR is the leading cause of vision loss in adults of working age. Patients and Methods: This is a longitudinal prospective study carried out at CADES/O concerning 198 diabetic patients. The selection criteria were that the media be transparent and the fundus accessible over a period of six months from February to July 2018. Results: A total of 73 patients (37%) presented with diabetic retinopathy with an average age of 49.5 +/−9 years. The sex ratio (M/F) was 0.6 with a female predominance of 59%. Liberal profession patients were the most numerous 47.5%. Type 2 diabetes was the most common (85.86%). Diabetes fundus assessment was the most common reason for consultation (52%). Arterial hypertension was the most incriminated risk factor (45.45%) followed by the poor balance of diabetes (40.90%), and the age of diabetes (28.28%). 9.5% had diabetic retinopathy complicated by rubella iris, neovascular glaucoma and retinal detachment. Conclusion: Diabetic retinopathy is a common condition for which early detection and regular monitoring must be the rule to prevent, slow down or avoids irreversible blindness if possible, induced by this pathology by a good balance of diabetes and good control of associated risk factors.

Study on Applications of Nanotechnology in Bamboo Charcoal Fibre

Nanotechnology (NT) deals with materials from 1 to 100 nm in length. Internationaly, NT is defined as the understanding, manipulation, and control of matter at the length mentioned above, thus, the physical, chemical, and biological properties of the materials (individual atoms, molecules, and bulk matter) can be engineered, synthesized, and altered to develop the next generation of improved materials, devices, structures, and systems. NT at the molecular level can be used to develop desired textile with special feature, such as high strength, unique surface structure, soft feeling, durability, water resistance, incombustibility, antimicrobial property, and so on. Indeed, NT has created numerous opportunities and challenges in the need of research, by the advancing of the technology in textile industry of China and the importing of bamboo charcoal fibers of nanotechnology from foreign countries. This paper focuses on summarizing recent applications of NT, its characters and functional test for bamboo charcoal fibers.

Remediation Technologies for Cadmium Contamination in Greenhouse Vegetable Fields

Based on the literature and experimental results, three kinds of soil amendments, namely rice biochar, hydroxyapatite and potassium dihydrogen phosphate(KH2PO4), and deeper ploughing were selected to evaluate the field application effect of soil amendments and agronomic measures on the remediation of Cd contamination in greenhouse vegetable fields. Cd-contaminated greenhouse screening was conducted from 2015 to 2017. In September 2017, comparative tests of eight treatments were performed, and a preferred test was performed in September 2018. The screening results of the contaminated areas indicated that the distribution of over-standard sites was uneven, and Cd content was significantly different. Over-standard rate of No.4 greenhouse was 83.33% and was the highest, and the average content of Cd in soil was 0.535 mg/kg. It was used as a comparative test greenhouse for eight treatments. No.1 greenhouse was selected as the preferred test greenhouse, with three over-standard plots having average Cd concentrations of 0.530, 0.568 and 0.792 mg/kg. The comparative test results showed that after 8 months of remediation, the content of available Cd in the treatment of hydroxyapatite+rice biochar+deeper ploughing(T6) was reduced by 32.55% compared with CK(the control) and 24.96% than 2 months of remediation. The content of available Cd using the treatment of potassium dihydrogen phosphate+rice biochar+deeper ploughing(T7) decreased by 47.88% compared with CK and 31.00% than 2 months of remediation. The preferred remediation test results showed that in the treatment of hydroxyapatite+rice biochar+deeper ploughing: the mean Cd content decreased from 0.489 to 0.372 mg/kg, reducing by 23.86%, and the mean did not exceed the standard. Compared with CK, the mean content of available Cd decreased by 10.71% after 8 months, and the lowest content of available Cd in three treatments was 0.133 mg/kg. In addition, the Cd content, bioconcentration factor(BCF) and translocation coefficient(TF) of bean aboveground plants were decreased by 15.86%, 23.68% and 25.77%, respectively when compared with CK. Rice biochar+hydroxyapatite +deeper ploughing is a favoured technology for the remediation of Cd-contaminated greenhouse vegetable fields.

Subsidence control method by inversely-inclined slicing and upward mining for ultra-thick steep seams

Ultra-thick steep coal seam mining will inevitably lead to the increase of greater and violent ground subsidence and deformation.A subsidence control method by inversely-inclined slicing and upward mining is proposed in this paper.By this method,the sequence of collapse of overlying strata and the direction of propagation of strata movement are changed,the extent of roof-side deformation thereby is lessened,and boundary angle of roof-side subsidence is reduced by 5°-10°.The mechanism of this mining method for control of strata movement has been evidenced by numerical simulation and experiments with similarity materials.A subsidence prediction model based on the variation of mining influence propagation angle can be used to evaluate the surface movement and deformation of the mining method.The application of the method in No.3 Mine in Yaojie mining area has yielded the expected result.

Spatial distribution characteristics of urban thermal conditions: application of GIS and remote sensing

The urban thermal distribution characteristics and its variation are dynamically monitored and synthetically analyzed by using GIS technology. The meteorological satellite data serve as main information source, assisted as auxiliary information sources by the landsat satellite TM data, land use thematic maps and meteorological observed data. A correlated pattern on the ground surface brightness temperatures and air temperatures has been studied and established with good performance of application.

A comprehensive review of in-situ polymer gel simulation for conformance control

Gel treatment has been widely applied in mature oilfields to improve sweep efficiency and control water production.Correct numerical simulation is of major importance to the optimization design and prediction of a successful gel treatment.However,there exist many problems in current simulation studies in published literature.This paper first presents a comprehensive review on the major factors that have been considered at different gelation stages during gel treatment,the models used in the commercial/inhouse simulators,and current numerical simulation studies on both laboratory and field scales.Then we classify the current in-situ gel numerical simulation problems as 1,deficient model problem that has published numerical model but has not been applied in simulator and application studies;2,missing model problem that does not have published quantitative model;and 3,inaccurate application problem that does not consider the major factors of gel performance,based on the reasons from some questionable results of current simulation studies.Finally,we point out the major research efforts that should be made in the future to better simulate in-situ gel treatment process.The review indicates that numerous simulation studies using commercial software packages intend to predigest the gel treatment,many of which,however,ignore important mechanisms and mislead the operation of gel treatment.In fact,a full assessment of simulating in-situ gels cannot be achieved unless the quantitative models can be qualified in terms of transport and plugging mechanisms based on the experimental results.

Study and Application of Mold Filling Simulation of Shaped Castings

In this paper, an algorithm for simulating fluid flow and heat transfer for mold filling of shaped castings is presented. The main features of the algorithm include: 1) a simple but practical technique based on VOF method to determine free surface, 2) an explicit scheme of enthalpy to solve the energy equation more efficiently, and 3) an effective treatment to modify the flux deviation due to pressure iteration. In order to verify these methods, well controlled experiments have been repeatedly done with both water analog and gray iron pouring experiments to record the flow patterns and temperature variations. The calculated results are in accordance with the experimental ones. For the applications, the simulated initial temperature distribution right after mold filling was used to analyse subsequent solidification and to predict shrinkage defects. Actual castings were poured and tested in a foundry plant. The reuslts show that the defects predication with considering fluid flow effects is more precise than that without considering the effects.

Study and Commercial Test on Technology for Deacidification of Distillate Oils

A new kind of solvent for deacidification of distillate oils was introduced in this paper. After successful laboratory study this technology had been applied in commercial scale successfully. Compared to traditional caustic wash of distillate oils, this technology has a lot of merits, such as the broad range of distillates to be processed, low caustic consumption, recycle of deacidifying agent, absence of waste caustic discharge, and low equipment revamp expenses, which can have promising perspectives for exploitation and application of this technology.

AN APPLICATION OF TOPOLOGICAL ANALYSIS TO STUDYING THE THREE-DIMENSIONAL FLOW IN CASCADES;PART I—TOPOLOGICAL RULES FOR SKIN-FRICTION LINES AND SECTION STREAMLINES

Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rules are (1) for a rotor cascade without shroud band, the total number of nodal points equals that the saddle points on the skin-friction line vector fields in eachpitch range; (2) for an annular or straight cascade with no-clearances at blade ends, the total number of saddle points is two more than that of nodal points on the skin-friction line fields in a pitch; (3) the total number of saddles in the secondary flow fields on cross-sections in cascade is one less than that of nodes; (4) in the section streamline vector fields on a meridian surface penetrating a flow passage, and on leading and trailing edge sections, the total number of nodes is equal to that of saddles; (5) on the streamline vector fields of a blade-to-blade surface, the total number of nodes is one less than that of saddles.

STUDY AND APPLICATION OF THE AERIAL PASSIVE MICROWAVE REMOTE SENSING

Ⅰ. Introduction Over the past two decades, microwave remote sensing has evolved into a focal point in the remote sensing area. This is due to the fact that in microwave band, we can acquire physical parameters about ocean, terrain and atmosphere on all weather condition. Research and application work about the aerial passive micro wave remote sensors has been done at Changchun Institute of Geography since 1973, under the unitary planning of Academia Sinica. Microwave radiometers of six freqency bands have been developed. Numerous remote sensing experiments were carried out, and large amount of scientific data were accumulated. Recently, theoretical models have

Application of Tectono Geochemical Study in Deep Concealed Ore Body Exploration--As the Huize Super-Large Lead-Zinc Deposit an exemple

1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou

An Application of the Modified Shear Lag Model to Study the Influence of Thermal Residual Stresses on the Stiffness and Yield Strength of Short Fiber Reinforced Metal Matrix Composites

The modified shear lag model proposed recently was applied to calculate thermal residual stresses and subsequent stress distributions under tensile and compressive loadings. The expressions for the elastic moduli and the yield strengths under tensile and compressive loadings were derived which take account of thermal residual stresses. The asymmetries in the elastic modulus and the yield strength were interpreted using the derived expressions and the obtained results of the stress calculations. The model predictions have exhibited good agreements with the experimental results and also with the other theoretical predictions

Chemical Indicator of Spinel During Partial Melting and Subsolidus Equilibration of Mantle Peridotite:Experimental Study and Application to Natural Rocks

Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 GPa. The results shows (1) during partial melting, Mg# [=Mg/(Mg+Fe)]and Cr# [=Cr/(Cr-Al)]of spinel increase with an increase in degrees of melting) (2) during subsolidus equilibration, with increasing temperatures, Mg# of spinel increases but Cr# of spinel remains almost unchanged in dunite and increases slightly in Iherzolite and harzburgite. The negative and quasi-linear Mg# -Cr# correlation of spinel represents an isotherm of total non-equilibrium. The same results have been obtained by means of mathematical modelling. It is also proved by Mg# -Cr# correlation of spinel in natural peridotites. As a result of the spinel subsolidus equilibration, only variation of Cr# of spinel is limited, and then Cr# of spinel can be used to estimate the relative degree of melting undergone by host rocks. The bigger Cr# of spinel is, the higher the degree of melting will be. By contrast, during crystallization magma, Mg# and Cr# of spinel decrease with decreasing temperatures. Likewise, Cr# of spinel in basalts may be used to indicate the feature of Cr2O3/Al2O3 of magma, and the compositional zoning of spinel may be used to study the evolution of magma (cooling rate and contamination).

Application of dual structure theory on motivating safe behavior of coal mine staff

Based on behavior science and direct causes analysis of serious accidents in Chinese coal mines in recent 5 years, a conclusion that unsafe behaviors of coal mine staff were the direct causes of these serious accidents was drawn, accounting for 91.3%. If staff was divided into executor and manager, percentages of the executor＇s and manager＇s unsafe behaviors in direct causes of the accidents were 69% and 54%, respectively, with executor＇s unsafe behavior as direct causes and manager＇s unsafe behavior as essential reasons after thorough analysis of these accidents. Further, on the basis of dual structure theory analysis, three new understandings, including transformation, hierarchy classification and representativeness of behavior factors were il- lustrated. Behavior factors of executors and managers in Chinese coal mines were summarized and classified by new recogni- tion. Then, dual structure theory was applied in a coal mine in Hebei Province of China; weakening unsafe behaviors and strengthening safe factors can attain the purpose of motivating safer behaviors in the coal mine.

STUDY AND APPLICATION OF SPECTROPHOTOMETRIC DETERMINATION OF MICRO AMOUNTS OF BISMUTH WITH MESO—TETRAKIS—(4—N—TRIMETHYL AMMONIUMPHENYL)PORPHINE

A new highly sensitive spectrophotometric method has been developed for the determination of micro amounts of bismuth (Ⅲ), based on the formation of Bi (Ⅲ)—meso—tetrakis—(4—N—trimethylammonium phenyl) porphine [T (4TMAP) P] complex. In the presence of Cd (Ⅱ), Bi(Ⅲ) reacts almost instantaneously with T (4TMAP)P in a 0. 6 mol/l NaAc—HAC buffer (PH5.8) at room temperature. The composition of the complex is T(4TMAP)P: Bi=1:1. The absorbance complex obeys Beer's law over the Bi(Ⅲ) concentration range 0.1—1.4 μg/ml. The linear relative coefficient γ is 0.9998. The apparent molar absorptivity was 1.75×10~5 1. mol^(-1). cm^(-1) at 463nm. The relative standard deviation of the method is 1.50％ for Bi(Ⅲ) 7ug/10ml (10 determinations). The interference of foreign ions has been examined. This simple and rapid method can be applied to the assay of Bi(Ⅲ) in some tablets directly.

Study on the Application of Gibberellin for the Spectrophotometric Determination of Arsenic,Phosphorus,Silicon and Germanium

In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 L.mol-1'cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.

ELECTROANALYTICAL STUDY OF XANTHOPHYLL AND ITS APPLICATION

The electroanalytical behaviour of xanthophyll was studied by differential pulse polarography and cyclic voltammetry.The reduction wave of xanthophyll at -0.92V(v.s.Ag/AgCl)in 1.25% tetrabutyl ammonium chloride solution(TBAC)was found for the first time.The optimum conditions for the determination of xanthophyll by DPP were established. The results from the application of cyclic voltammetry to study electrode process behaviour showed that the electrode reaction of xanthophyll at a hanging mercury electrode is quasi-reversible reaction.