Primary energy conversion performance of “Pendulor” wave energy device with bottom gap

Lekha. U. Bakmeedeniya,S.D.G.S.P. Gunawardane,김병하,이영호 한국마린엔지니어링학회 2020 한국마린엔지니어링학회지 Vol.44 No.4

“Pendulor,” a wave energy device, is the first notable oscillating wave surge converter (OWSC), which consists of a top hinged flap that oscillates in a bounded caisson. From the sea tests conducted by the Muroran Institute of Technology, Japan, it is proven to present 40%–50% energy conversion efficiency. Nevertheless, there are unresolved issues, particularly regarding the phys-ical configurations of the caisson and the flap combination when adopting the OWSC under different sea conditions. The main objec-tive of this research is to investigate the effect of the parametric interactions of caisson configurations on the conversion efficiency. This paper describes the test facility arrangements and the obtained model test results, particularly for the primary energy conversion efficiency of the device for selected configurations. Three-dimensional model tests were conducted in a wave tank to investigate the behavior of a straight caisson configuration using a 1/40th scale following the Froudian scaling for regular waves. Tests were con-ducted for the conventional caisson arrangement (flap without a gap in the caisson) and for a flap with a bottom gap. The results ob-tained for the power extraction for different combinations of the damping torque and the wave frequencies were analyzed to compare the power capture for the above caisson configurations. The discovery of the “pumping mode,” which enhances the power capture, is discussed and was verified in this study.

Differential Level of Host Gene Expression Associated with Nucleopolyhedrovirus Infection in Silkworm Races of Bombyx mori

Lekha, Govindaraj,Vijayagowri, Esvaran,Sirigineedi, Sasibhushan,Sivaprasad, Vankadara,Ponnuvel, Kangayam M. Korean Society of Sericultural Science 2014 International Journal of Industrial Entomology Vol.29 No.2

The variation in the level of immune response related gene expression in silkworm, Bombyx mori following infection with Bombyx mori nucleopolyhedrovirus (BmNPV) was analyzed at different time intervals. The occlusion bodies of BmNPV orally inoculated to the two most divergent silkworm races viz., Sarupat (resistant to BmNPV infection) and CSR2 (susceptible to BmNPV infection) were subjected to oral BmNPV inoculation. The expression profile of gp 41 gene of BmNPV in the Sarupat and CSR2 races revealed that the virus could invade the midguts of both susceptible and resistant races. However, its multiplication was significantly less in the midgut of resistant race, while, in the susceptible race, the viral multiplication reached maximum level within 12 h. These findings indicate that potential host genes are involved in the inhibition of viral multiplication within larval midgut. The immune response genes arylphorin, cathepsin B, gloverin, lebocin, serpin, Hsp 19.9, Hsp 20.1, Hsp 20.4, Hsp 20.8, Hsp 21.4, Hsp 23.7, Hsp 40, Hsp 70, Hsp90 revealed differential level of expression on NPV infection. The gloverin, serpin, Hsp 23.7 and Hsp 40 genes are significantly up-regulated in the resistant race after NPV infection. The early up-regulation of these genes suggests that these genes could play an important role in baculovirus resistance in the silkworm, B. mori.

Differential Level of Host Gene Expression Associated with Nucleopolyhedrovirus Infection in Silkworm Races of Bombyx mori

( Govindaraj Lekha ),( Esvaran Vijayagowri ),( Sasibhushan Sirigineedi ) 한국잠사학회 2014 International Journal of Industrial Entomology Vol.29 No.2

The variation in the level of immune response related gene expression in silkworm, Bombyx mori following infection with Bombyx mori nucleopolyhedrovirus (BmNPV) was analyzed at different time intervals. The occlusion bodies of BmNPV orally inoculated to the two most divergent silkworm races viz., Sarupat (resistant to BmNPV infection) and CSR2 (susceptible to BmNPV infection) were subjected to oral BmNPV inoculation. The expression profile of gp41 gene of BmNPV in the Sarupat and CSR2 races revealed that the virus could invade the midguts of both susceptible and resistant races. However, its multiplication was significantly less in the midgut of resistant race, while, in the susceptible race, the viral multiplication reached maximum level within 12 h. These findings indicate that potential host genes are involved in the inhibition of viral multiplication within larval midgut. The immune response genes arylphorin, cathepsin B, gloverin, lebocin, serpin, Hsp 19.9, Hsp 20.1, Hsp 20.4, Hsp 20.8, Hsp 21.4, Hsp 23.7, Hsp 40, Hsp 70, Hsp90 revealed differential level of expression on NPV infection. The gloverin, serpin, Hsp 23.7 and Hsp 40 genes are significantly up-regulated in the resistant race after NPV infection. The early up-regulation of these genes suggests that these genes could play an important role in baculovirus resistance in the silkworm, B. mori.

Sensing properties of polyoxomolybdate doped polyaniline nanomaterials for oxidising and reducing volatile organic compounds

P. Chithra lekha,M. Balaji,S. Subramanian,D. Pathinettam Padiyan 한국물리학회 2010 Current Applied Physics Vol.10 No.2

The polyoxomolybdates encapsulated PAni hybrid materials are prepared by interfacial polymerisation. In P12MPA, the crystal structure of 12MPA is not modified on doping with PAni. However, P11MPA have the polycrystallinity due to the presence of vanadium in the dopant molecule. Though, the hybrids prepared by interfacial polymerisation are in emaraldine salt form, there is a blue shift in the absorption spectra due to dopant induced decrease in conjugation length and over-oxidation. Interfacially polymerised PAniPOM hybrid materials are exposed with various concentrations of vapours of different volatile organic compounds (VOC) such as acetone, methanol, chloroform and carbon tetrachloride. The oxidising VOCs like acetone and methanol on exposure to PAni decrease the resistivity by hydrogen bonding with the redox cites of the polymer. Among these two, the sensitivity towards acetone is more in PAni and its hybrids which can be linked with the vapour pressure of the analyte. Due to the weak acidic characteristics of chlorinated hydrocarbons which are reducing vapours, the resistivity of PAni and its hybrids increases on exposure to chloroform and CCl4. Here, the chlorinated hydrocarbons interact with the redox sites of PAni and reduce it to base form. Bridging of polymer chains is also proposed for the reduction of conductivity on exposure to the analyte. The sensitivity is higher for the reducing analytes than that of the oxidising one.

Inclusion of polyaniline in electrodeposited bismuth sulphide thin films: Synthesis and characterization

S. Subramanian,P. Chithra lekha,D. Pathinettam Padiyan 한국물리학회 2009 Current Applied Physics Vol.9 No.5

Structural, electrical and optical properties of polyaniline (PAni) doped Bi2S3 composite thin films prepared by electrodeposition method are reported. X-ray diffraction pattern indicates its polycrystalline nature and crystallite size increases with increase in the concentration of PAni. FTIR studies reveal that the dopant PAni has affected the absorption phenomenon in the IR region of the Bi2S3 thin films. The optical band gap energy is found to be 1.91 eV for as-deposited Bi2S3 thin film and it decreases with increase in the concentration of PAni. The morphology of the doped films changes due to the addition of PAni. in the concentration of PAni. The morphology of the doped films changes due to the addition of PAni. The conduction results from a hopping due to localized states in the temperature range 300–358 K. Above 358 K, the conduction process is explained by the traps at grain boundaries of partially depleted grains.

A Randomized Controlled Study to Compare the Total and Hidden Blood Loss in Computer-Assisted Surgery and Conventional Surgical Technique of Total Knee Replacement

Amit Singla,Rajesh Malhotra,Vijay Kumar,Chandra Lekha,G. Karthikeyan,Vishwas Malik 대한정형외과학회 2015 Clinics in Orthopedic Surgery Vol.7 No.2

Background: Total knee arthroplasty (TKA) is associated with considerable blood loss. Computer-assisted surgery (CAS) is different from conventional TKA as it avoids opening the intramedullary canal. Hence, CAS should be associated with less blood loss. Methods: Fifty-seven patients were randomized into two groups of CAS and conventional TKA. In conventional group intramedullary femoral and extramedullary tibial jigs were used whereas in CAS group imageless navigation system was used. All surgeries were done under tourniquet. Total and hidden blood loss was calculated in both groups and compared. Results: The mean total blood loss was 980 mL in conventional group and 970 mL in CAS group with median of 1,067 mL (range, 59 to 1,791 mL) in conventional group and 863 mL (range, 111 to 2,032 mL) in CAS group. There was no significant difference in total blood loss between the two groups (p = 0.811). We have found significant hidden blood loss in both techniques, which is 54.8% of the total loss in the conventional technique and 59.5% in the computer-assisted navigation technique. Conclusions: There is no significant difference in total and hidden blood loss in the TKA in CAS and conventional TKA. However, there is significant hidden blood loss in both techniques. There was no relation of tourniquet time with blood loss.

High-energy ion induced physical and surface modifications in antimony sulphide thin films

S. Subramanian,M. Balaji,P. Chithra Lekha,K. Asokan,D. Kanjilal,Indra Sulania,Jai Prakash,D. Pathinettam Padiyan 한국물리학회 2010 Current Applied Physics Vol.10 No.4

Sb2S3 thin films prepared by electrodeposition on indium tin oxide coated glass substrate were irradiated with 150 MeV Ni11+ ions for various fluence in the range of 1011–1013 ions/㎠. The modifications in the structure, surface morphology and optical properties have been studied as a function of ion fluence. X-ray diffraction (XRD) analysis indicates a shift in the (2 4 0) peak position towards lower diffraction angle and a decrease in grain size with increase in ion fluence. Presence of microcracks due to irradiation induced grain splitting effect has been observed from the SEM micrograph at higher ion fluence. The optical absorbance spectrum revealed a shift in the fundamental absorption edge and the band gap energy increased from a value of 1.63 eV for as-deposited films to 1.80 eV for the films irradiated with 1013 ions/㎠.

Human Action Recognition Bases on Local Action Attributes

Zhang, Jing,Lin, Hong,Nie, Weizhi,Chaisorn, Lekha,Wong, Yongkang,Kankanhalli, Mohan S The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Human action recognition received many interest in the computer vision community. Most of the existing methods focus on either construct robust descriptor from the temporal domain, or computational method to exploit the discriminative power of the descriptor. In this paper we explore the idea of using local action attributes to form an action descriptor, where an action is no longer characterized with the motion changes in the temporal domain but the local semantic description of the action. We propose an novel framework where introduces local action attributes to represent an action for the final human action categorization. The local action attributes are defined for each body part which are independent from the global action. The resulting attribute descriptor is used to jointly model human action to achieve robust performance. In addition, we conduct some study on the impact of using body local and global low-level feature for the aforementioned attributes. Experiments on the KTH dataset and the MV-TJU dataset show that our local action attribute based descriptor improve action recognition performance.

Human Action Recognition Bases on Local Action Attributes

Jing Zhang,Hong Lin,Weizhi Nie,Lekha Chaisorn,Yongkang Wong,Mohan S Kankanhalli 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Human action recognition received many interest in the computer vision community. Most of the existing methods focus on either construct robust descriptor from the temporal domain, or computational method to exploit the discriminative power of the descriptor. In this paper we explore the idea of using local action attributes to form an action descriptor, where an action is no longer characterized with the motion changes in the temporal domain but the local semantic description of the action. We propose an novel framework where introduces local action attributes to represent an action for the final human action categorization. The local action attributes are defined for each body part which are independent from the global action. The resulting attribute descriptor is used to jointly model human action to achieve robust performance. In addition, we conduct some study on the impact of using body local and global low-level feature for the aforementioned attributes. Experiments on the KTH dataset and the MV-TJU dataset show that our local action attribute based descriptor improve action recognition performance.