Swayamjit Roy

The Northcap University · Law

This paper demonstrates 100 kHz Kr planar laser-induced fluorescence in a non-reacting jet. This is repetition rate is 10,000 times faster than previous nanosecond-duration Kr PLIF measurements, providing the potential to time-resolve high-speed flows.

The feasibility of high-speed (10–50 kHz) cinematographic X-ray radiography of liquid sprays with correlated time sequences of thousands of images is demonstrated utilizing a high-flux, rotating-anode tube source. Quantitative path-integrated liquid distributions are acquired in an impinging jet spray by modeling the X-ray source spectrum, liquid a...

Single-shot, two-color, volumetric laser-induced fluorescence was demonstrated for three-dimensional (3D), tomographic imaging of the structural properties of the OH radical and temperature field in a turbulent hydrogen- air flame. Two narrowband laser sources were tuned to the Q1(5) and Q1(14) transitions of the (1,0) band in the A²Σ → X²π system...

This paper describes an analysis of the mechanisms of autoignition-controlled flame initiation and flame stabilization in a nonpremixed jet in crossflows, using simultaneous high-speed (10 kHz) tomographic particle image velocimetry, OH-PLIF and line-of-sight flame emissions. Measurements are conducted on a turbulent, transverse, reacting propane j...

We demonstrated single-shot, three-dimensional temperature field measurements in a turbulent hydrogen-air flame using two-color hydroxyl radical volumetric laser-induced florescence (OH-VLIF). Four high-speed intensified cameras with shared quadscopes were used for tomographic temperature field imaging.

Flash x-ray radiography is used to capture quantitative, two-dimensional line-of-sight averaged, single-shot liquid distribution measurements in impinging jet sprays. The accuracy of utilizing broadband x-ray radiation from compact flash tube sources is investigated for a range of conditions by comparing the data with radiographic high-speed measur...

Two-photon laser-induced fluorescence (TPLIF) is a well-recognized approach for detecting atomic oxygen however, measurements to date have been restricted to a single point within a flow, flame, or plasma, due to the inherently high intensity requirements for the excitation laser. Furthermore, the high-intensity ultraviolet (UV) photons used for tw...

The study of time-dependent phenomena in turbulent flames requires detailed knowledge of both the chemistry and flowfield interactions that are present in regions of localized extinction or ignition. Recent developments in burst-mode laser technology, coupled with high-speed CMOS detectors, allow imaging at rates sufficient to resolve small-scale v...

In this paper, International quality Tasar spun silk yarn was successfully produced from tasar silk waste on worsted system of spinning. After spinning, degumming loss, yarn realization and economics have been measured. These yarns were tested for characterisation according to international standard testing methods. Results have been compared and a...

Chirped-probe-pulse (CPP) femtosecond (fs) coherent anti-Stokes Raman scattering (CARS) spectroscopy for single-laser-shot temperature measurements in flames is discussed. In CPP fs CARS, a giant Raman coherence is created in the medium by impulsive pump-Stokes excitation, and the temperature-dependent temporal decay of this initial coherence is ma...

Femtosecond coherent anti-Stokes Raman scattering (fs-CARS) spectroscopy has recently emerged as a promising laser-based temperature-measurement technique in flames. In fs-CARS, the broad spectral bandwidths of the pump and Stokes lasers permit the coupling of each ro-vibrational Raman transition via a large number of pump-Stokes photon pairs, crea...

Spatially resolved thermometry at speeds up to 1000 Hz is demonstrated using 1-D femtosecond CARS. Such measurements can provide invaluable data for validating turbulent combustion models as well as addressing spatio-temporal instabilities.

Fuel-rich streaks or dissociated combustion products exiting from gas turbine combustors may react with jets of turbine vane cooling air. These inverse diffusion flames in a vitiated cross-flow can potentially cause structural failure of turbine vanes due to the excessive heat fluxes. In this study two-color OH planar laser induced fluorescence the...

To expand use of silk in diversified products, new silk yarns with new characteristics have to be developed. Production of blend silk yarns during silk reeling process is one of the attempts in this regard. The mechanism and gadgets required for production of blend silk yarns have been developed and fixed to CSTRI multi-end reeling machine. The ble...

There is reduction in bursting strength of soft silk fabrics in dry and wet state for 500 and 1000 cycles of abrasion and there is higher reduction in wet state. The dependence of fabric abrasion resistance on cover factor of fabric and its weight and crimp balance is established beyond doubt. Eight varieties of degummed soft silk fabrics were prod...

The study of the natural pigmentation and its wash fastness properties of natural coloured silk involwes through investigation and quantification of fading property of Tasar, Muga & Nistari silk fabrics. The natural colouring matter of silk can therefore be roughly diwided into yellow, green and brown pigments. An effort is made to find the fading...

In this paper, the plain fabrics of Red Eri and wool spun yarn fabric are woven on power loom by using 2/60s count of yarn in warp and weft. These fabrics have been tested for various low stressmechanical and surface properties as per international standard testing methods. Handle values have been evolved & results have been compared with wool spun...

CSTRI, Bangalore has recently attempted to improvise the Ambar Charka spinning machine into a power driven machine aiming at qualitative as well as quantitative improvement in the production of spun silk yam. Central Silk Technological Research Institute (CSTRI), Bangalore, has made attempts to produce quality spun yarn on the same spinning machine...

Sericin is a protein material, which is adhered to the fibroin filaments while the formation of natural silk by the silk worm. The sericin content and its characteristics in natural silk varies from one variety to the other. There are four varieties of silk, either cultivated or naturally grown. They are Mulberry silk (Bombyx mori), Tasar (Antherea...

The effect of cocoon cooking condition on cocoon filament unwinding tension, reeling characteristics and quality of silk has been studied. Study has been conducted using Daba tasar cocoons using pressurized cooking and improved cooking method. Cocoon cooking conditions influence significantly the reeling characteristics and quality of raw silk. Res...

The global demand for organic cotton and silk materials has witnessed an increase and the general requirement of the production varies. Silk being an agro-based industrial product, both the farm as well as the industry line of the operations should conform to the organic requirements. The natural fibers must be certified as organic by an accredited...

In this paper 2/60s spun yarn has been successfully spun on worsted system of spinning from Eri and wool fibre. From these yarns plain fabric was woven on power loom using same count in both warp and weft. These fabrics have been tested for mechanical properties, according to international standard testing methods. The results have been compared an...

The Central Silk Technological Research Institute (CSTRI), Bangalore, has standardized the entire process of tasar reeling. The institute introduced the improvised CSTRI Two-in-one reeling-cum-twisting machine model-2. Experimental trial in reeling showed higher productivity, quality, and superior working conditions. The intervention also addresses...

The Indian zari industry moves through a series of processes before it reaches the final stage and various ways of differentiating between pure zari from artificial zari are listed. The silver or gold wire is wrapped around the silk yarn and this yarn is used for ornamentation in different applications namely, embroidered apparel, furnishing, and c...

Mulberry silk yarn samples were extracted for the estimation of heavy metals by two methods, dry ash method and extraction under perspiration condition. The extracts were analysed using Atomic Absorption Spectrophotometer and quantified the Copper, Cadmium and Zinc contents. There was no significant correlation between the heavy metals extracted by...

Different races of mulberry and non-mulberry cocoon samples from different places and yarn samples from different lots of imported silk were analysed for the total heavy metal contents using Atomic Absorption Spectrophotometer. All the samples analysed showed the presence of Copper, Cadmium and Zinc in a range of 1.24 to 33.34mg/kg, 00.00 to 40.72m...

The evenness of dyeing is quantified in terms of unlevelness index. In this work, the effect of different shade depths on the evenness of silk yarn dyeing was studied

A study was conducted to investigate the relationship between sericin dissolution and reelability percentage of CSR2×CSR4 bivoltine hybrid cocoons. Based on statistical analysis, it was found that there was a correlation between the solubility and the reelability of the cocoons at 5% level. It was observed that in the cocoon filament sericin having...

Central Siilk Technological Research Institute (CSTRI), Bangalore has developed an elliptical denier detecting and mechanical indicating mechanism suitable for multi-end reeling machine. The influence of this device on quality characteristics of raw silk in the case of CSTRI multi-end reeling machine has been studied using bivoltine hybrid and mult...

Microscopic, Physical and Mechanical properties of Mulberry, Eri Muga, Tasar and peduncle Tasar silk fibre have been studied according to international standard testing methods. Results have been compared as per the requirement of industry. The results of the investigation thoroughly discussed It is revealed that Tasar, Eri and Muga silk has elonga...

In this paper, the weft backed fabric has been woven on power loom by using 2/60s white Eri spun silk yarn in warp and 2/20s white Eri spun silk yarn in the weft. The fabric has been raised from mechanical raising machine. Both the fabric i.e. raw as well as raised fabrics have been tested for various low stress mechanical and surface properties as...

When fabric is rubbed against surface, abrasion of the fibre surface occurs due to friction. Abrassion is the rubbing away of component fibres and yarns of the fabric. The fabric wear of the material depends on the construction of yarn or fabric. The life of the fabric depends on the resistance to abrasion. Moreover the type of fibre determines the...

We report the detection of acetylene (C2H2) at low concentrations by electronic resonance-enhanced coherent anti-Stokes Raman scattering (ERE-CARS). Visible pump and Stokes beams are tuned into resonance with Q-branch transitions in the v2 Raman band of acetylene. An ultraviolet probe beam is tuned into resonance with the [(A)\tilde]\tilde{A}–[(X)\...

In this paper, the weft backed fabric has been woven in power loom by using 2/80s white Eri spun silk yam in warp and 2/20 s white Eri spun silk yarn in the weft. The fabric has been raised in mechanical raising machine. Both the fabric i.e. raw as well as raised fabrics have been tested for various mechanical properties, according to international...

A study was done at the Central Silk Technologies Research Institute (CSTRI) on the feasibility of large scale mill spinning of eri cocoons. The cocoons were degummed and spun using the cotton, worsted (Japanese and Italian technologies), and woolen systems. The spinning performance of eri silk was better than mulberry silk. The yield percentage of...

In this paper, brick red eri cocoons have been degummed and processed in worsted system upto draw frame (gill box) stage to get eri tops. These Eri tops and wool tops have been successfully blended in Draw frame stage of spinning and spun 2/80s yarn with 6 combination. In the paper results of investigations carried out on blending of Indian Eri sil...

The Central Silk Technological Research Institute (CSTRI), Bangalore, India, has standardized degumming methods for two varieties of eri cocoons, white and brick red, for mill spinning by employing Japanese, Italian, and Open bath type techniques. White eri cocoons were degummed with CSTRI method at M/s. Karnataka Silk Industries Corporation (KSIC)...

In this paper, Eri cocoons have been degummed successfully processed in worsted system of spinning. Degumming loss, yarn realization and economics have been measured. Eri fibre, Eri spun silk yarn, and dyed yarn character have been tested according to international standard testing method. Results have been compared among White, Brick red Eri and m...

The Central Silk Technological Research Institute (CSTRI) in association with one of the authorized multiend reeling machine manufacturers, M/s Silmac Industries, has developed a conveyor-cooking machine suitable for Indian filatures. The machine consists of two tanks made of 10swg/3mm thickness stainless steel sheets having 36″ width × 146″ length...

The Central Silk Technological Research Institute (CSTRI), India, has made a comparative study of three different systems to produce eri noil, recommending open-end spinning for its techno-economic advantages. The sequence of activities followed under the condenser system spinning include a lattice opener, forst breaker card, second breaker card, f...

Application of dual-pump, dual-broadband (DPDB) coherent anti-Stokes Raman scattering (CARS) for the measurement of temperature and multiple-species mole fractions is presented for the first time in a liquid-fueled combustor of practical interest. In this system pure rotational transitions of O2–N2 and the ro-vibrational transitions of CO2–N2 are p...

The raising effect of Eri yarn or Eri spun silk is in operation that is suitable for manufacturing all varieties of fabrics such as fleece denim fabrics, sarees, inner wear, ornamental fabrics, wall hangings, and hosiery fabrics. Raising is used to obtain a relatively deep hairy surface, but the degree of depth depends upon the technique used. The...

A tasar reeling machine has been developed by the Central Silk Tehnological Research Institute (CSTRI), Bangalore, India, to discourage the traditional practice of thigh reeling by the women weavers. The Tasar/Muga Reeling-cum-Twisting Machine (THRTM) is based on M.S. Iron fabrication with angles and bars. The machine is 62 inches in height, 41 inc...

A range of fancy yarns has been developed by Central Silk Technological Research Institute (CSTRI), Bangalore, India, from eri and mulberry spun silk yarns, to bring in a effect with a difference which adds value to the fabrics. These fancy yarns are produced from cotton, polyester, viscose, and nylon fibers, and are being used in knitted goods, bl...

The influence of the whiteness of Indian bivoltine cocoons on reeling characteristics has been studied. The Whiteness of the cocoons (CSR 2 X CSR 4 race and its reciprocal) reared in different places were found to have significant influence on reeling characteristics viz., groping end efficiency, reelability, raw silk percentage and waste generated...

Simultaneous planar laser-induced fluorescence (PLIF) of the OH radical and laser-induced incandescence (LII) are demonstrated in the reaction zone of a liquid-fueled, swirl-stabilized model combustor. The OH radical is used to study the flame structure, while LII provides measurements of soot volume fraction. The frequency-doubled output of an Nd:...

The present system of dupion reeling involves Live cocoon reeling/Stem stifling→Charka reeling→Finished skeins. Further details are supplied. Following a field survey conducted by the Central Silk Technological Research Institute (CSTRI), Bangalore, four dupion quality problems have been identified. Dupion silk is consumed only by handlooms and fet...

A diode-laser-based sensor has been developed for ultraviolet absorption measurements of the nitric oxide (NO) molecule. The sensor is based on the sum-frequency-mixing (SFM) of the output of a tunable, 395 nm external cavity diode laser (ECDL) and a 532 nm diode pumped, frequency-doubled Nd:YAG laser in a beta-barium-borate (BBO) crystal. The sum...

An all-solid-state continuous-wave (cw) laser system for mid-infrared absorption measurements of the carbon monoxide (CO) molecule has been developed and demonstrated. The single-mode, tunable output of a 60-mW, 860-nm external-cavity diode laser (ECDL) is difference-frequency mixed with the output of a 550 mW diode-pumped cw Nd:YAG laser in a peri...

The Combustion and Laser Diagnostics Research Complex (CLDRC) supports the experimental and computational study of fundamental combustion phenomena to expand the scientific knowledge base; validate combustor-design codes; and improve the performance of future-generation propulsion systems for military and commercial aviation. This state-of-the-art...