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This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM2.5 and PM10 from industrial areas of Odisha State, India. During 2017–2018, bimonthly sampling of PM10 and PM2.5 was carried out for 24 h in the industrial and mining areas of Jharsuguda and Angul in Odisha during the pre-monsoon, monsoon, and post monsoon seasons. Highest mean concentration of ∑16PAHs in PM2.5 was observed during the post monsoon (170 ng/m3) period followed by pre-monsoon (48 ng/m3) and monsoon (16 ng/m 3) periods, respectively. A similar trend of ∑16PAHs was also observed in PM10 with higher levels observed during post monsoon (286 ng/m3) followed by pre-monsoon (81 ng/m3) and monsoon (27 ng/m3) seasons. Diagnostic ratios and principal component analysis suggested diesel, gasoline and coal combustion as the major contributors of atmospheric PAH pollution in Odisha. Back trajectory analysis revealed that PAH concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents ranged between 0.24 and 94.13 ng TEQ/m3. In our study, the incremental lifetime cancer risk ranged between 10–5 and 10–3, representing potential cancer risk.

The Inconel 718 has captured global attention for its huge applications in the aerospace and defense field. However, a limited approach is noticed to investigate this material's responses and morph...

The recently developed composite ‘AA6092/17.5 SiCp-T6’ is gradually capturing the attention of the defense and aviation sectors, where various fabrication and material processing are required to accomplish. Considering this emerging demand, it may require to generate a few integrated shapes or micro-slots on this material. Therefore, the responses and textural features of the surfaces are analyzed here to evaluate the suitability of EDM-operation for future processing. Experiments are executed for various flushing velocities and three different discharge conditions and noticed an excellent response in all aspects. The machining rate increases with flushing velocity for low and medium discharge conditions but finally drops by 35–37.5% when the velocity is more than 10 m/s. However, the higher discharge energy can hold the machining rate up to a higher velocity level and the highest MRR of 29.27 mm3/min is obtained at 12 m/s flushing velocity. The textural features are mostly akin for low and medium discharges, and few solidified defects like indentation, flakes, thermal spots, cracks, etc., appear on the surface, which is absent for high discharge energies. The EDM-process ensures proper carbonation and heat-treatment to the surface, and a better hardness can be obtained with a higher current and low duty factor.

Gap-active electrical discharge machining (GA-EDM) is a novel approach which provides a gap-sensible and auto-adjustable electrode-retraction system. This mechanism is conceptualized from the principle of ‘parallel-plate capacitor having two dielectric mediums’ where the inter-electrode surfaces are acted as the parallel plates. The kerosene is used as a fundamental dielectric substance, and a relatively denser and viscous layer of bio-oil is treated as secondary dielectric material. Besides this, a servo-controlled tool arrangement is employed, which is auto-sensible and synchronized with the flushing system. This multi-dielectric enhances the equivalent capacitance of the plasma-column and can dissipate huge energy during the discharging phase. The extensive heat melts most of the solidification defects and reforms the entire texture, which is far better than the surface developed with normal EDM. Moreover, the viscous layer of the secondary fluid (above the workpiece) provides an adhesive grip and slow heat dissipation procedure, which can check the formation of micro-cracks, develop due to residual effect of rapid quenching. Besides these, the flushing sensible electrode retraction system ensures an adequate passage for flushing, which helps in proper debris-expelling and controlled heat dissipations. Therefore, the adopted gap-active (GA) mechanism can facilitate better textual features with negligible indentation, solidified-agglomerates, and cracks. It is observed that the secondary dielectric enriches the carbon containments in the texture and forms a 10–14 % harder surface than the normal-EDM.

3-Aminoquinoline (3AQ) has been used as a fluorescent probe for preferential solvation in hexane-ethanol solvent mixtures. Results of the present experiment have been put into context by comparison with prior observations with 5-aminoquinoline (5AQ) as the probe. 3AQ exhibits a relatively small change of dipole moment (Δμ = 2.2 D) upon photoexcitation, compared to 5AQ (Δμ = 6.1D), which might appear to be a hindrance in the way of its use as a solvation probe. Indeed, the values of parameters like spectral shifts are smaller for the present experiment with 3AQ. At the smallest concentration of alcohol used, its local mole fraction around the probe is significantly lower than in the previous experiments with 5AQ. However, these apparent disadvantages are outweighed by the significant increase in fluorescence intensity and lifetime observed with increasing concentration of ethanol in the solvent mixture, as opposed to the drastic fluorescence quenching that occurs for 5AQ. This is a marked advantage in the use of 3AQ in studies like the present one. The local mole fraction of ethanol and preferential solvation index experienced by 3AQ are in line with those reported for 5AQ. The disadvantage of the smaller magnitude of Δμ persists in the time resolved fluorescence experiments, for solvent mixtures with very low ethanol content. Negligible wavelength dependence of fluorescence transients of 3AQ is observed for x p = 0.002,. However, this effect is outweighed at higher alcohol concentrations, for which nanosecond dynamics of preferential solvation is observed.

The alternative dielectrics like vegetable oils, emulsions, and different organic solutions have captured the emerging research attentions, and few pieces of literature also discussed about their p...

This article has been addressed various sustainability aspects of EDM and introduced transesterified neem as a green dielectric. Here, the machining is performed at 4–16 A of current, 50–250 μs of pulse on time, 10–50 μs of pulse off time, and 20-50 V of gap voltage using both the kerosene and neem as a dielectric medium. The comparative assessment of the obtained responses claims that the neem dielectric exhibits 22% more removal rate and 17% less surface roughness than kerosene. Apart from these, the impact of each dielectric on the texture of processed surfaces has been assessed with the help of the microscopic images captured with a scanning electron microscope (SEM). Finally, the sustainability evaluation is performed to check the feasibility of the neem oil as a reliable dielectric of EDM. It is observed that the neem dielectric is capable of ensuring comparatively fine surface textures due to the repeated overlapping of the radially extended craters and consumes less time to attain the targeted removal depth (RD). Therefore, based on the results, the neem dielectric can be recommended as a potent and reliable alternative of conventional kerosene.

This article deeply focused on the sustainability issues of EDM and evaluated the feasibility of transesterified jatropha, canola and neem oil as an alternative of conventional kerosene. Therefore these bio dielectrics are judged in terms of removal rate, surface integrities, taper cut and overcut under various ranges of process parameters and flushing velocities. More over computational fluidics and electro thermal modeling are also used to investigate the heat dissipation patterns and crater formations of both conventional (kerosene) and bio dielectrics under various flushing velocity. It is observed that all the bio dielectrics ensure better MRR and less SR than kerosene but out of them the performances of jatropha and canola are remarkable in so far MRR and SR are concerned. The obtained results indicate that due to less axial and wider radial extension of the developed crater the neem dielectric exhibits 18% more overcut and 40% more tapper cut than kerosene and on the other hand canola ensures 12% less SR because of the same reason. But the developed surfaces subject more heat affected zone and thermal cracks because of poor heat dissipation rate, higher viscosity and less flowability of the bio dielectrics. Moreover these bio dielectrics do not exhibit impressive MRR at low flushing velocity (

Micro-chip removal and heat dissipation are two important and essential utilities of dielectric medium along with its vital contribution in plasma channel formation, which has a significant influence in metal removal, tool wear, and surface integrity. The vapor bubbles, which are formed after every progressive spark, expand and collapse in the electric field and finally condensed inside the dielectric medium. As the localized heat and excess temperature of the eroded spot increases, the dynamic properties of the bubbles accelerate and develop a lower pressure region, which is responsible for dielectric flushing. In this paper, the integrated approach of vapor bubble dynamics and computational fluid dynamics is used to study the dynamic behavior and heat dissipation of dielectric fluid through the plasma channel. At the very beginning of machining, the excess temperature is comparatively low; so, the detached bubbles are condensed inside the fluid medium and are not able to move above the free surface. However, as the temperature of the machined zone rises, excess temperature also increases and bubbles are able to carry the heat up to the free surface of the dielectric medium and finally condense. This phenomenon is very much analogous to the boiling process. Earlier, many simulation processes are used by researchers to investigate heat flux and heat dissipation rate of the dielectric fluid, but, here, vapor bubble dynamics and periodic heating are introduced to consider heat absorption by vapor bubbles, which gives more accurate heat transfer analysis of electric discharge machining. It is observed that the adopted model has the accuracy level of more than 95% with 4.5–4.6% of average prediction error and 1.5–2% more efficient than the existing models.

This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM

In this study we aim to assess 16 priority PAHs enlisted by the US Environmental Protection Agency in PM 2.5 and PM 10 for the first time from industrial areas of Odisha State in India. During 2017–2018, bimonthly sampling of PM 10 and PM 2.5 were carried out for 24 hours by respirable dust sampler and PM 2.5 sampler respectively, in the industrial and mining areas of Jharsuguda (n = 2) and Angul (n = 4) during the pre-monsoon, monsoon and post monsoonal seasons. Highest average concentration of ∑ 16 PAHs in PM 2.5 was observed during post monsoon (170 ng/m3) followed by pre-monsoon (17–89 ng/m3; avg, 48 ng/m3) and monsoonal season (2–40 ng/m3 ; avg, 16 ng/m 3 ), respectively. Similar trend of ∑ 16 PAHs levels in PM 10 was seen with higher levels during post monsoon (116–471 ng/m3; avg, 286 ng/m3) followed by pre-monsoon (avg, 81 ng/m3) and monsoon seasons (27 ng/m3. Diagnostic ratios BaA/(BaA + Chry), Phe/(Phe + Ant) and Flt/(Flt + Pyr) and principal component analysis (PCA) suggest diesel, gasoline and coal combustion are the major contributors for atmospheric PAHs pollution in Odisha. Back trajectories analysis revealed that PAHs concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents (TEQs) ranged between 0.24 to 94.13 ng TEQ/m3. In our study incremental lifetime cancer risk (ILCR) ranged between 10 − 5 and 10 − 3 representing potential cancer risk.

Low removal rate, high power consumption, and dependency on conventional fuels (kerosene as a dielectric) are some premier issues that keep the sustainability index of EDM low, though it has huge acceptability and popularity mostly in aviation sectors and biomedical instrumentation to machine some extensively hard ferrous and nonferrous metal/metal alloys. Besides these, the thermal agitation inside the fusion/machining zone partially burns the dielectrics and tool–workpiece–metal, which evolve some oxides/monoxides. These evolved gases promote an unhygienic breathing atmosphere, which is very much harmful to the operator’s health. Sometimes because of inadequate flushing pressure and velocity, carbon particles deposited inside the crater makes the spark unstable and releases carbon monoxide when the temperature exceeds its melting point. According to ISO 14000, every manufacturing process must be comprised of the sustainability criteria, which maintains a compromised balance between the economic, environmental, and social aspects, including the issue of the operator’s health. But in real practices, it is very tough to maintain a stoichiometric balance between all these constraints. The article intensely focuses on the issue of emergence of gases during machining and tries to promote the utility of some alternative vegetable oil-based dielectrics, which are experimentally justified as a potent alternative of conventional kerosene. Apart from these, it includes some comparative talks on dielectric nature and their impacts on the responses and surface properties. Finally, this article highlights some compromise solutions which are probably capable of mitigating the hurdles to some extent, so that the sustainable machining can be encouraged in real sense.

Rotary ultrasonic machining (RUM) is an abrasive based advanced machining technique for cutting and finishing of various hard and fragile materials like ceramic, ceramics composite, glass, titanium and its alloy etc. RUM is the development over stationary ultrasonic machining for enhancement of MRR, geometrical accuracy and surface roughness. The basic mechanism of RUM is the combination of ultrasonic machining and conventional diamond grinding. In this chapter development, principle, mechanism, setup details of rotary ultrasonic machining has been discussed. It also highlights the effects of diverse input parameters on performance of RUM. The MRR always increases with spindle speed; tool feed rate and ultrasonic power. The surface roughness improved with spindle speed but worse with tool feed rate and ultrasonic power. The chipping size reduced with spindle speed but increase with tool feed rate and ultrasonic power. The cutting force reduces with spindle speed and ultrasonic power but increases with tool feed. Various advancements in RUM has also discussed. A new technique for drilling called robotic rotary ultrasonic drilling (RRUD) was developed. The application area of rotary ultrasonic machining (RUM) in micro domain has also been highlighted. It is extensively useful for generation of micro feature like micro hole, micro channel, complex micro cavity etc. on various materials such as quartz, glass, SiC, and Al2O3.

The wide utility of the EDM in industrial and biomedical sectors has drawn the attention of the researchers in the last few decades. In the meantime, intensive works have been performed to improve the machining performance of the EDM. Addition of powder additives in dielectric medium is one of those approaches which moderate the strength of the plasma channel by increasing the concentration of the ions. Powder dusts of copper, titanium, aluminum, tungsten, silicon/silica and carbon nanoparticles are some of the additives which have significant contributions on EDM process parameters. In this work the Si–Cu hybrid powder dust is added with kerosene oil and the comparative analysis is done based on the performance evaluations in terms of material removal rate (MRR) and surface roughness (SR). Silicon and copper are used individually earlier with other powder dust, but here both are added together with dielectric medium to evaluate their combined effects on surface characterizations. Because of the highly conductive nature of the copper, it increases the mobility of the ions and charge particles inside the ionization gap. On the other side, silicon is partially conductor and partially insulator in nature. So because of its semi-conductive properties, it can restrict the spark span and domain which possesses controlled machining. Therefore, the combined influence of these two powder additives gives some excellent features which are highlighted in this article.

The year round insufficiency of water in rivers of Tripura (state of North-East India) is the main problem of hydro-power generation of this state. The only hydro-power station of the stale (Dombor Hydro-Power Plant) is presently in deadly condition. So a plant which can operate with fixed volume of water, is very much acceptable to pursuit this condition. So, pump storage hydro power plant is this type of plant which can operate according to the expected condition. But consumption of power during the pumping phase reduces the net output of PSP hydro-plant. So parametric estimation has been adopted to find the most beneficial & non beneficial parameters for PSP and how the efficiency changes with the variation of these parameters it is also observed here. Finally the optimum condition for maximum power generation has been developed from these estimations.

Probiotic microorganisms have been utilized for many years in food processing, preservations and for nutraceutical health benefits. There are a large number of pharmaceutical formulations containing probiotic microorganisms available in the market worldwide. Majority of these organisms are the members specifically from genera Lactobacillus, Lactococcus and Bifidobacterium. A number of media have been proposed for selective or differential enumeration of lactobacilli and bifidobacteria in mixed populations. The development of selective medium using different types of ingredients and antibiotic are well practiced. In the present study we have developed a selective medium for the enumeration of Lactobacillus acidophilus by utilizing the antibiotic ofloxacin resistance of the organism in Lactobacilli MRS-agar. Samples were analyzed by determining viable counts in reference Lactobacilli MRS agar and selective Lactobacilli MRS-ofloxacin agar media. The results were statistically analyzed to evaluate the precision, accuracy, reproducibility and selectivity of the method developed. Thus MRS containing ofloxacin medium can be used for selective enumeration of Lactobacillus acidophilus strains available in commercial formulations containing Bifidobacterium species.

The Electric Discharge Machining is one of the popular non-traditional approaches which has huge utility in industrial sectors, mostly in die-making industries and as well as in bio-medical fields. But more power consumption, evolvement of unhygienic gases, development of non- biodegradable wastes, etc. are some curtail issues, which leads the poor sustainability of the EDM operation. In this approach, transesterified neem is introduced as a new and green dielectric medium of EDM, and its impacts on EDM responses are examined. Here, machining is carried out between 4 A to 10 A ranges of input current, 100 μ-sec to 200 μ-sec of pulse ON time and 10 μsec to 30 μ-sec of pulse OFF time using both kerosene and transesterified neem as a dielectric medium. The responses like MRR, surface roughness, and microscopic views of machined surfaces are analyzed to check the viability of transesterified neem as a dielectric medium of EDM.It is experimentally observed that transesterified neem as a dielectric medium ensured 6.2 % to 15.6 % more removal rate and 12.25 % to 15.45 % less surface roughness than kerosene.

A control strategy is suggested for converging harmonics with hybrid filter. The hybrid power filter is constituted by a series active filter and shunt passive filter. The control algorithm works on dual formulation of electric power vectorial theory. Without depending on the system impedance, the active filter improves the compensation characteristic of the shunt passive filter and eliminates the series/shunt resonance problem, the voltage waveform injected by the active series filter is able to compensate for reactive power, eliminates harmonics in load current and balances asymmetrical load.