Wing and leg amputation induced oviposition pattern of tropical tasar silk moth, Antheraea mylitta Drury (Lepidoptera: Saturniidae) in oviposition devices – Earthen cups and paper sheets

Mohanraj Soundappan S,Dinesh Kumar,Bhagavanulu M.V.K.,Chandrashekharaiah M.,M. S. Rathore,Srinivas C. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Antheraea mylitta Drury (Lepidoptera: Saturniidae) is a tropical semi-domesticated wild tasar silkworm reared by marginal tribal farmers of India. Due to improper egg laying frequency, oviposition is generally kept for three continuous days after amputating the gravid moth wings (W – ) in earthen cups (C). In order to systematize the oviposition frequency, wing cut with leg cut (W – L – ) was performed in ecorace Daba trivoltine (DTV) completing three life-cycles in a year. Oviposition of (C)W – L – was observed in all three grainages during the year 2020 and compared with (C)W – moths. Oviposition was also accomplished on plain paper sheets (S). It is observed that (C) W – obtained 63–67% and (C)W – L – obtained 72–80% egg laying on first day. Similarly, (S)W – and (S)W – L – ob tained 68–71% and 74–83% on first day. Further, significant high oviposition was observed within first four hours in both earthen cups and on paper sheets by W – L – moths laying 49–69% and 55–65% eggs compared to W – laying 25–45% and 39–44% eggs, respectively. A total of 44–51, 47–54, 44–48 and 46–52 eggs/g moth weight was obtained in (C)W – , (C)W – L – , (S)W – and (S)W – L – , respectively in three consecutive grainage. Oviposition of W – moths in earthen cups and on paper sheets are not significantly different indicating earthen cups in contemporary tasar grainage could be replaced with paper sheets. Thus, the paper demonstrates for the first time a fast, efficient and scalable cellular oviposition of A. mylitta on paper sheets comparable to Bombyx mori

Multispectral Image Compression for various band images with High Resolution Improved DWT SPIHT

V. Bhagya Raju,Dr. K. Jaya Sankar,Dr. C. D. Naidu,Srinivas Bachu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.2

Satellite imageries which comprises of various multispectral spectral bands pertaining to spectral and spatial information of the images acquired by latest multispectral sensor technology are rapidly increasing day by day in the recent years for onboard satellite remote sensing applications. A lossy multispectral image compression is desired by the exploitation of the redundancies present in the spatial and spectral information while preserving the vital and crucial information of the image objects to a certain extent. In this paper a novel approach is proposed for lossy multispectral image compression which is an extension to the earlier existing algorithms. In this proposed method the multispectral images are first enhanced with interpolation based super resolution technique to estimate a hi-resolution (HR) image from a low-resolution (LR) input image. Secondly the decorrelated spectral bands transformed by discrete wavelet transform (DWT), which contain maximum entropy, are selected and these representative spectral bands are quantized and encoded using Improved SPIHT (ISPIHT) algorithm. The algorithm has been designed for the optimization of maximum coding efficiency and for high compression ratio of bits per pixel per band when compared with the well known compression techniques.

Magnetic and Electrical Transport Properties of Intermetallic Fe-based Heusler Alloys

M. Vasundhara,S.C. Shin,V. Srinivas 한국자기학회 2009 한국자기학회 학술연구발표회 논문개요집 Vol.2009 No.5

Ratcheting Fatigue Behavior of Modified 9Cr–1Mo Steel at Room Temperature

Prerna Mishra,R. S. Rajpurohit,N. C. Santhi Srinivas,G. V. S. Sastry,Vakil Singh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Fusion reactor components undergo asymmetric cyclic loading,that leads to a progressive increase in plastic strain andcauses deterioration in life of engineering components. This investigation deals with fatigue behavior of modified 9Cr–1Mosteel at room temperature and presents the effect of mean stress (σm), stress amplitude (σa) and stress rate ( ̇ ) on fatigue life,deformation and fracture behavior under asymmetric cyclic loading. A series of fatigue tests were conducted under asymmetricstress-controlled loading with different combinations of σm (190–210 MPa), σa (400–420 MPa) and ̇ (50–450 MPa/s). The plastic strain increased with increase in σm and σa and the fatigue life was reduced, whereas increase in ̇ reduced theaccumulated plastic strain and the cyclic life was increased. The deformation behavior and microstructural changes under theinfluence of the three parameters (σm, σa and ̇ ) were examined by tranmission electron microscope (TEM). With increasein the three parameters (σm, σa, ̇ ), the lath martensitic structure changed to subgrain structure along with dislocation cellsand forest dislocations. Scanning electron microscopy revealed unique features of fractured specimens, with progressivereduction in diameter towards the fracture-end, fatigue striations on the tapered circumferential surface and dimples on thefracture surface.

The substitution effect of boron on reentrant behavior of rapidly solidified Fe–Mn–Zr alloys

Kim, K.S.,Yu, S.C.,Srinivas, V. Elsevier 2007 Materials science & engineering. properties, micro Vol.449 No.-

<P><B>Abstract</B></P><P>We have studied the magnetic properties of boron-substituted amorphous reentrant Fe–Mn–Zr alloys. The magnetic characterization of a-Fe<SUB>82</SUB>Mn<SUB>8−<I>x</I></SUB>B<SUB><I>x</I></SUB>Zr<SUB>10</SUB> (numbers indicate at.%) alloys has been done through the studies of thermal variation of magnetization, ac susceptibility and ferromagnetic resonance. Low-temperature spin freezing was observed at 54K with large coercivity and low magnetic moment for a-Fe<SUB>82</SUB>Mn<SUB>8</SUB>Zr<SUB>10</SUB>. The large coercivity at low temperatures and high freezing temperature for this sample is attributed to magnetic hardening. With an increase of the concentration of B, it is observed that the Curie temperature increases and the spin-glass-like transition observed at low temperature moves to lower temperatures and finally vanishes at <I>x</I>=8at.%. A single resonance peak in FMR spectrum was observed below <I>T</I><SUB>C</SUB> and at least two distinct line shapes were observed well beyond the <I>T</I><SUB>C</SUB> for two of the compositions, namely, <I>x</I>=4 and 6. These observations could be qualitatively understood in terms of a finite spin clusters plus an infinite ferromagnetic matrix model. It can also be concluded that the magnetic disorder is reduced as boron concentration is increased.</P>

Ratcheting Fatigue Behaviour of Zircaloy‑2 at 300 °C

R. S. Rajpurohit,Prerna Mishra,N. C. Santhi Srinivas,S. R. Singh,V. Singh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9

In laboratory, materials designed for engineering applications, specifically for fatigue, are generally tested under symmetricalcyclic loading (stress ratio, R = −1), but many structural components exhibit less fatigue life than predicted from symmetricloading due to asymmetric cyclic loading during service. This study deals with fatigue behaviour of Zircaloy-2 and presentsthe effect of mean stress (σm), stress amplitude (σa), stress rate ( ̇ ) on fatigue life, deformation and fracture behaviour at300 °C under asymmetric cyclic loading. A series of fatigue tests are performed at 300 °C under asymmetric stress-controlledloading with different combinations of σm (60–80 MPa), σa (115–135 MPa) and ̇ (30–750 MPa/s). Deformation behaviourand microstructural changes under the influence of above parameters (σm, σa and ̇ ) are examined by transmission electronmicroscope. It is observed that plastic strain increases with rise in σm as well as σa and cyclic life is reduced; on the otherhand, with increase in ̇ accumulation of plastic strain decreases and fatigue life is enhanced. The results are correlated withmicrostructural changes and fracture behaviour of the material under different test conditions.

The Substitution Effect of Boron on Reentrant Behavior of Rapidly Solidified FeMnZr Alloys

Y. M. Moon,K. S. Kim,S. C. Yu,V. Srinivas 한국자기학회 2004 Journal of Magnetics Vol.9 No.4

The magnetization properties have been measured for amorphous Fe_(82)Mn_(8-x)BxZr_(10) (x = 0-8) alloys. The temperature dependence of magnetization for these alloys shows the existence of antiferromagnetic couplings between Fe atoms in low fields at low temperatures. The magnetic parameters, obtained from the magnetization behavior are consistent with the presence of mixed magnetic state. The Curie temperature and magnetic moment increased with an increase of the concentration of B and spin glass like transition observed at low temperature decreases and finally vanishes at x = 8 at%. Our result suggests that the substitution of B for Mn seems to cause an increase of magnetic order.

Theoretical simulation on evolution of suspended sodium combustion aerosols characteristics in a closed chamber

Sujatha Pavan Narayanam,Amit Kumar,Usha Pujala,Subramanian V.,Srinivas C.V.,Venkatesan R.,Athmalingam S.,Venkatraman B. 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

In the unlikely event of core disruptive accident in sodium cooled fast reactors, the reactor containmentbuilding would be bottled up with sodium and fission product aerosols. The behavior of these aerosols iscrucial to estimate the in-containment source term as a part of nuclear reactor safety analysis. In thiswork, the evolution of sodium aerosol characteristics (mass concentration and size) is simulated usingHAARM-S code. The code is based on the method of moments to solve the integro-differential equation. The code is updated to FORTRAN-77 and run in Microsoft FORTRAN PowerStation 4.0 (on Desktop). Thesodium aerosol characteristics simulated by HAARM-S code are compared with the measured values atAerosol Test Facility. The maximum deviation between measured and simulated mass concentrations is30% at initial period (up to 60 min) and around 50% in the later period. In addition, the influence ofhumidity on aerosol size growth for two different aerosol mass concentrations is studied. The measuredand simulated growth factors of aerosol size (ratio of saturated size to initial size) are found to bematched at reasonable extent. Since sodium is highly reactive with atmospheric constituents, the aerosolgrowth factor depends on the hygroscopic growth, chemical transformation and density variations besides coagulation. Further, there is a scope for the improvement of the code to estimate the aerosoldynamics in confined environment