A Unique Modelling Strategy to Dynamically Simulate the Performance of a Lobe Pump for Industrial Applications

The performance of a newly designed tri-lobe industrial lobe pump of high capacity is simulated by using commercial CFD solver Ansys Fluent. A combination of user-defined-functions and meshing strategies is employed to capture the rotation of the lobes. The numerical model is validated by comparing the simulated results with the literature values. The processes of suction, displacement, compression and exhaust are accurately captured in the transient simulation. The fluid pressure value remains in the range of inlet pressure value till the processes of suction and displacement are over. The instantaneous process of compression is accurately captured in the simulation. The movement of a particular working chamber is traced along the gradual degree of lobe’s rotation. At five different degrees of lobe’s rotation, pressure contour plots are reported which clearly shows the pressure values inside the working chamber. Each pressure value inside the working chamber conforms to the particular process in which the working chamber is operating. Finally, the power requirement at the shaft of rotation is estimated from the simulated values. The estimated value of power requirement is 3.61 BHP FHP whereas the same calculated theoretically is 3 BHP FHP. The discrepancy is attributed to the assumption of symmetry of blower along the thickness.

Coal washing scenario in India and future prospects

Coal Washing Exploration in India dates back to 1900s; though, first coking coal washeries in India were installed after independence. At present, most of the coking coal washeries are owned by Public Sector Companies; whereas, most of the non-coking coal washeries are owned by Private Sector. Even after six decades of coal washing practices, there has not been significant development in the coal washing intelligentsia. Indian Coal Washing industry is still dependent on imported equipment, which has been designed to treat coal that is significantly different from Indian coal of drift origin. In this paper, authors have ventured into evolution of Indian Coal Washing Industry （with a focus on coking coal washing sector）, its present condition and future prospect for growth. The paper emphasizes need for developing indigenous solutions to industrial challenges and highlights importance of increased coordination among academia-research institutions and coal industry.

Effects of laser phase transformation hardening parameters on heat input and hardened-bead profile quality of unalloyed titanium

Laser transformation hardening(LTH)of unalloyed titanium of 1.6 mm-thick sheet,nearer to ASTM Grade 3 of chemical composition was investigated using 2 kW CW Nd:YAG laser.The effects of laser power(750-1 250 W),scanning speed(1 000-3 000 mm/min)and focal point position(from-10 to-30 mm)on the heat input,and hardened-bead geometry(i.e.hardened bead width(HBW),hardened depth(HD)and angle of entry of hardened bead profile with the surface(AEHB))were investigated using response surface methodology(RSM).The experimental plan is based on Box-Behnken design matrix method.Linear and quadratic polynomial equations for predicting the heat input and the hardened bead geometry were developed.The results indicate that the proposed models predict the responses adequately within the limits of hardening parameters being used.It is suggested that regression equations can be used to find optimum hardening conditions for desired criteria.

Characterization of magnetically impelled arc butt welded T11 tubes for high pressure applications

Magnetically impelled arc butt(MIAB) welding is a pressure welding process used for joining of pipes and tubes with an external magnetic field affecting arc rotation along the tube circumference. In this work, MIAB welding of low alloy steel(T11) tubes were carried out to study the microstructural changes occurring in thermo-mechanically affected zone(TMAZ). To qualify the process for the welding applications where pressure could be up to 300 bar, the MIAB welds are studied with variations of arc current and arc rotation time. It is found that TMAZ shows higher hardness than that in base metal and displays higher weld tensile strength and ductility due to bainitic transformation. The effect of arc current on the weld interface is also detailed and is found to be defect free at higher values of arc currents. The results reveal that MIAB welded samples exhibits good structural property correlation for high pressure applications with an added benefit of enhanced productivity at lower cost.The study will enable the use of MIAB welding for high pressure applications in power and defence sectors.

Effect of thermal cycle on Ni-Cr based nanostructured thermal spray coating in boiler tubes

Ni-Cr based nanostructured feedstock powder was prepared by mechanical milling technique involving repeated welding, fracturing, and re-welding of powder particles in a planetary ball mill. The milled nanocrystalline powders were used to coat carbon steel tubes using high velocity oxygen fuel（HVOF） thermal spraying process. The characterization of the feedstock powder and HVOF coated substrates was performed using optical microscope, X-ray diffractometer（XRD）, scanning electron microscope（SEM）, high resolution transmission electron microscope（HR-TEM）, energy dispersive spectrometer（EDS） and microhardness tests. The coated and uncoated samples were subjected to different thermal cycles and characterized for their phase changes, metallurgical changes and microhardness variations. Ni-Cr nanostructured coated samples exhibited higher mechanical and metallurgical properties compared to their conventionally coated counter parts. The results showed that the nanostructured coating possessed a more uniform and denser microstructure than the conventional coating.

Optimisation of laser welding parameters for welding of P92 material using Taguchi based grey relational analysis

Creep strength enhanced ferritic(CSEF) steels are used in advanced power plant systems for high temperature applications. P92(Cr–W–Mo–V)steel, classified under CSEF steels, is a candidate material for piping, tubing, etc., in ultra-super critical and advanced ultra-super critical boiler applications. In the present work, laser welding process has been optimised for P92 material by using Taguchi based grey relational analysis(GRA).Bead on plate(BOP) trials were carried out using a 3.5 k W diffusion cooled slab CO_2 laser by varying laser power, welding speed and focal position. The optimum parameters have been derived by considering the responses such as depth of penetration, weld width and heat affected zone(HAZ) width. Analysis of variance(ANOVA) has been used to analyse the effect of different parameters on the responses. Based on ANOVA, laser power of 3 k W, welding speed of 1 m/min and focal plane at-4 mm have evolved as optimised set of parameters. The responses of the optimised parameters obtained using the GRA have been verified experimentally and found to closely correlate with the predicted value.? 2016 China Ordnance Society. Production and hosting by Elsevier B.V. All rights reserved.

Epidemiology, clinical features and transmission of re-emerging arboviral infection chikungunya

A number of re-emerging and emerging infectious diseases including chikungunya, West Nile, yellow fever, Zika, dengue, Japanese encephalitis, and others have increased in recent years, which threaten the public health across the globe. Chikungunya is a neglected re-emerging arboviral infection caused by chikungunya virus. Arboviral infections such as chikungunya, Zika and dengue have similar epidemiology, transmission cycles and clinical symptoms, which makes it difficult to diagnose these three infections. Moreover, there is no commercial vaccine or licensed therapy available for chikungunya infection, thus causing severe burden worldwide. Vector control may reduce the disease risk; however, this remains a challenge due to many factors including, but not limited to, evolution of insecticide resistance in mosquitoes, gaps in vector control tools, urbanization, environmental and demographic changes. Effective integrated vector control strategies and surveillance measures along with affordable vaccine development or anti-viral therapy are essential to control the infection. In this review, we discuss the epidemiology of mosquito-borne infection chikungunya which has re-emerged as an international concern in recent decades.

Variation of chemical composition of high strength low alloy steels with different groove sizes in multi-pass conventional and pulsed current gas metal arc weld depositions

25 mm thick micro-alloyed HSLA steel plate is welded by multi-pass GMAW and P-GMAW processes using conventional V-groove and suitably designed narrow gap with 20 mm(NG-20) and 13 mm(NG-13) groove openings.The variation of weld metal chemistry in the multi pass GMA and P-GMA weld depositions are studied by spark emission spectroscopy.It is observed that the narrow groove GMA weld joint shows significant variation of weld metal chemistry compared to the conventional V-groove GMA weld joint since the dilution of base metal extends from the deposit adjacent to groove wall to weld center through dissolution by fusion and solid state diffusion.Further,it is noticed that a high rate of metal deposition along with high velocity of droplet transfer in P-GMAW process enhances the dilution of weld deposit and accordingly varies the chemical composition in multi-pass P-GMA weld deposit.Lower angle of attack to the groove wall surface along with low heat input in NG-13 weld groove minimizes the effect of dissolution by fusion and solid state diffusion from the deposit adjacent to groove wall to weld center.This results in more uniform properties of NG-13 P-GMA weld in comparison to those of NG-20 and CG welds.

单冰晶石(四氟铝酸钠)在铝电解工业的应用

本文介绍了单冰晶石作为氟化铝的一种实用而又有较高经济利益的替代品在铝电解槽中的应用。

A Study on the Correlation of Physiological and Psychological Health Hazards in Human Habitats with Seismicity, Mountain Air Turbulence and Environmental Infrasound

A statistical correlation study on the basis of published data has been performed in order to find whether an abnormal degree of human physiological ailments and a psychology of sustained violent reactions in highly populated habitats are correlated with environmental infrasound emissions related to seismic activity and sustained by mountain air turbulence. The study focus is on Latitude 34° North coinciding with boundaries of colliding Tectonic Plates in three continents. Earthquakes, rock fractures and landslides in these regions are creating geoacoustic activity in the form of hotspots of infrasound emissions. Sources of infrasound have been located by global infrasound monitoring stations. One single earthquake can cause multiple infrasound sources in a region. Low frequency “infrasound” creates an environment of unseen and inaudible energies that are hazardous to the local population. In one region on 34°N latitude the percentage of population with hearing disabilities increases or decreases almost directly proportional to frequency of earthquakes. In this region, the casualties due to social disorder and violence increased as the frequency of earthquake events increased and decreased as this frequency decreased. Comprehensive public health studies bring out that a sizable percentage of the regional population remain in a constant state of irritation, annoyance and anger;and suffer many other psychosomatic ailments corresponding to exposure to infrasound in 5 - 16 Hz frequencies and 120 - 140 dB amplitude. A new natural hazard inimical to life on planet earth has thus been identified. The time has arrived for public health authorities to locally pinpoint infrasound hotspots by scientific measurements. Thereafter new technologies can be developed to actively, and passively, mitigate/cancel these hazardous environmental emissions of infrasound and a Public Health Security Systems put in place as sustainable solutions for a healthy, livable habitat.

Microstructure and mechanical properties of friction welded carbon steel(EN24) and nickel-based superalloy(IN718)

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel(EN24) and nickel-based superalloy(IN718), and the microstructures of three distinct weld zones—the weld interface(WI)/thermo-mechanically affected zone(TMAZ),the heat-affected zone(HAZ), and the base metal—were examined.The joint was observed to be free of defects but featured uneven flash formation.Electron backscatter diffraction(EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ.Moreover, significant refinement in grain size(2 –5 μm) was observed at the WI/TMAZ with reference to the base metal.The possible causes of these are discussed.The microhardness profile across the welded joint shows variation in hardness.The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates.The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.

pharmacognostical study and establishment of quality parameters of aerial parts of Costus speciosus-a well known tropical folklore medicine

Objective:To evaluate the diagnostic pharmacognostical characters of Costus speciosus(aerial parts)along with their physico-chemical parameters and fluorosence analysis.Method:The pharmacognostical characters were determined in terms of macroscopy,microscopy,powder microscopy,leaf constant,fluorescence analysis and preliminary phytochemical investigation.Results:The findings of macroscopy revealed that leaves elliptic to oblong or oblong-lancoelate,thick,spirally arranged,with stem clasping sheaths up to 4 cm,flowers large,white,conelike terminal spikes,with bright red bracts.Transverse section of leaflet showed the presence of cuticularised epidermis with polygonal cells on adaxial surface and bluntly angled cells on abaxial surface of lamina,mesophyll cells differentiated in to single layered palisade cells on each surface and 2-3 layered spongy parenchyma,unicellular and uniseriate multicellular covering trichomes,paracytic stomata and vascular bundles surrounded by sclerenchymatous multicellular sheath.Preliminary phytochemical screening exhibited the presence of various phytochemical groups like alkaloids,glycosides,steroids,phenolic constituents.Further,the leaf constants,powder microscopy and fluorescence characteristics indicated outstanding results from this investigation Conclusions:Various pharmacognostical and physico-chemical parameters have pivotal roles in identification,authentication and establishment of quality parameters of the species.

Optimal Scheduling of Air Conditioners for Energy Efficiency

Energy saving is one of the most important research hotspots, by which operational expenditure and CO2 emission can be reduced. Optimal cooling capacity scheduling in addition to temperature control can improve energy efficiency. The main contribution of this work is modeling the telecommunication building for the fabric cooling load to schedule the operation of air conditioners. The time series data of the fabric cooling load of the building envelope is taken by simulation by using Energy Plus, Building Control Virtual Test Bed （BCVTB）, and Matlab. This pre-computed data and other internal thermal loads are used for scheduling in air conditioners. Energy savings obtained for the whole year are about 4% to 6% by simulation and the field study, respectively.

Influence of Medium Used during Ferritic Nitro-Carburizing of AISI H-13 Hot Work Tool Steel

Ferritic nitro-carburizing is one of the most popular surface hardening methods used to improve lifespan of hot work tool steels.Different types of mediums like gas,liquid,plasma and fluidized bed are generally used during ferritic nitro-carburizing process.In this paper,various ferritic nitro-carburizing methods were compared where gas,salt bath and fluidized are used as mediums.AISI H-13 hot work tool steel specimens were treated by using these different methods of nitro-carburizing and their performance was evaluated by using micro-structural and mechanical analysis.Optical microscopy,micro-hardness testing and X-ray stress analyzer were used for specimen characterization.Moreover,pin on disk dry sliding wear tests were performed to compare wear performance of specimens treated with different nitro-carburizing methods.It is perceived that,medium used during nitro-carburizing has significant influence on the final surface properties that can be achieved by ferritic nitro-carburizing.

Influence of Deep Cryogenic Treatment (DCT) on Thermo Mechanical Performance of AISI H13 Tool Steel

Deep cryogenic treatment (DCT) is one of the most recent processes being used to treat tool steels. It is a supplementary treatment where components are treated below subzero temperatures for several cryo-soaking hours. This paper focuses on to study the effect of deep cryogenic treatment on Thermo mechanical properties of AISI H-13 tool steel. Deep cryogenic treatment at 32 hours of cryo-soaking time is applied and thermo mechanical performance of tool steel was analyzed by using pin on disk high temperature wear testing and stress rupture testings. The microstructural evolutions during DCT were evaluated by using scanning electron microscope (SEM). It was observed that microstructural modifications like increase in carbide density, fine and uniform martensitic structure during DCT had significantly improved properties.

Diabetes Prediction Using Derived Features and Ensembling of Boosting Classifiers

Diabetes is increasing commonly in people’s daily life and represents an extraordinary threat to human well-being.Machine Learning(ML)in the healthcare industry has recently made headlines.Several ML models are developed around different datasets for diabetic prediction.It is essential for ML models to predict diabetes accurately.Highly informative features of the dataset are vital to determine the capability factors of the model in the prediction of diabetes.Feature engineering(FE)is the way of taking forward in yielding highly informative features.Pima Indian Diabetes Dataset(PIDD)is used in this work,and the impact of informative features in ML models is experimented with and analyzed for the prediction of diabetes.Missing values(MV)and the effect of the imputation process in the data distribution of each feature are analyzed.Permutation importance and partial dependence are carried out extensively and the results revealed that Glucose(GLUC),Body Mass Index(BMI),and Insulin(INS)are highly informative features.Derived features are obtained for BMI and INS to add more information with its raw form.The ensemble classifier with an ensemble of AdaBoost(AB)and XGBoost(XB)is considered for the impact analysis of the proposed FE approach.The ensemble model performs well for the inclusion of derived features provided the high Diagnostics Odds Ratio(DOR)of 117.694.This shows a high margin of 8.2%when compared with the ensemble model with no derived features(DOR=96.306)included in the experiment.The inclusion of derived features with the FE approach of the current state-of-the-art made the ensemble model performs well with Sensitivity(0.793),Specificity(0.945),DOR(79.517),and False Omission Rate(0.090)which further improves the state-of-the-art results.

Influence of Shot Peening on DIN 1.2714 Hot Work Tool Steel

Shot peening is one of the most popular surface enhancement technique used to improve fatigue performance of different materials. This paper focuses on to study the effect of different shot peening parameters on micro-structural and mechanical properties of DIN 1.2714 tool steel specimens. Shot peening treatments were carried out by varying shot size and peening intensity. X-ray stress analysis, micro-hardness testing and micro-structural analysis were performed to characterize these specimens. In addition, pin on disk wear testing was executed to recognize wear behavior of this shot peened tool steels. It was observed that along with compressive residual stress generation, shot peening also induces work hardening effect and modifies surface structure which are responsible for significant improvement in this tool steel.

High Temperature Oxidation and Hot Corrosion Behaviour of 9Cr 1Mo Ferritic Cold Rolled Steel in Air at 900°C under Cyclic Condition

The oxidation behaviour of 10%, 30%, and 50% cold rolled and unprocessed 9Cr 1Mo ferritic steels in air have been studied under isothermal conditions at a temperature of 900°C in a cyclic manner. Oxidation kinetics was established for all samples on which experiment was conducted in air at 900°C under cyclic conditions for 50 cycles by thermogravimetric technique. Each cycle consisted of 1 hour heating at 900°C followed by 20 min of cooling in air. 10% cold rolled sample followed parabolic rate of oxidation while 30% cold rolled sample showed accelerated rate of weight gain. X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray (SEM/EDAX) techniques were used to characterise the oxidized sample and their scales. 10% cold rolled steel was found to be more corrosion resistance than other in air oxidation for 50 cycles.

Hot Corrosion Behaviour of Yttria-Stabilised Zirconia as Plasma Sprayed Coated Boiler Steel in Air and Salt at 900°C under Cyclic Condition

Yttria-Stabilised Zirconia (YSZ) coatings were deposited on a T-22 boiler steel. NiCrAlY was used as bond coat and YSZ as top coat. Hot corrosion studies were conducted on uncoated as well as plasma spray coated specimens in air as well as salt (75 wt.% Na2SO4 + 25 wt.% NaCl) at 900°C under cyclic conditions. The thermogravimetric technique was used to establish kinetics of corrosion. X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive x-ray analysis (SEM/EDAX) techniques were used to analyse the corrosion products. This YSZ overlay coatings enhance resistance to corrosion significantly which can be attributed to formation of zirconium oxides (ZrO2) and yttrium oxide (Y2O3). This coating was more effective in salt environment and there is an extra phase of ZrS.

Method Development and Validation for Simultaneous Estimation of Montelukast Sodium and Desloratadine by RP-HPLC

A novel, precise, accurate, rapid and cost effective isocratic reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed, optimized and validated for the simultaneous estimation of Montelukast Sodium (MON) and Desloratadine (DES) in pharmaceutical dosage forms. The drugs were estimated using Hypersil BDS C18 (250 mm × 4.6 mm I.D., 5 μ particle size) column. The mobile phase composed of orthophosphoric acid and water in the ratio of 20:80 v/v, at a flow rate of 1.0 ml/min was used for the separation. Detection was carried out at 280 nm. The linearity range obtained was 10 - 30 μg/ml for MON and 5 - 15 μg/ml for DES with retention times of 2.929 min and 4.439 min for MON and DES respectively. The correlation coefficient values were found to be 0.999. Precision studies showed % RSD values less than 2% for both the drugs in all the selected concentrations. The percentage recoveries of MON and DES were in the range of 99.59% - 99.82% and 99.60% - 99.80% respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 0.176 μg/ml, 0.587 μg/ml for MON and 0.087 μg/ml, 0.292 μg/ml for DES respectively. The method was validated as per the International Conference on Harmonization (ICH) guidelines. The proposed validated method was successfully used for the quantitative analysis of commercially available tablet dosage forms.