Disperser-induced bacterial disintegration of partially digested anaerobic sludge for efficient biomethane recovery

Banu, J. Rajesh,Kannah, R. Yukesh,Kavitha, S.,Gunasekaran, M.,Yeom, Ick Tae,Kumar, Gopalakrishnan Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.347 No.-

<P><B>Abstract</B></P> <P>The present study highlights the options to enhance the methane potential of partially digested anaerobic sludge using disperser-induced bacterial disintegration. Floc dispersion with no biomass disintegration was achieved at a disperser-specific energy input of 9.5 kJ/kg TS. The outcomes of both sole bacterial disintegration (S-BD) and disperser-induced bacterial disintegration (D-BD) were assessed in terms of changes in lysate, biopolymer release and increase in biodegradability and methane generation. A higher lysate solubilization of about 22.4% was achieved in D-BD compared to S-BD (11.3%), indicating the efficiency of floc dispersion prior to bacterial disintegration. The biochemical methane result implies that D-BD shows higher methane potential of 0. 279 gCOD/gCOD. Considering the overall outcome achieved in this study, disperser-induced bacterial disintegration is proved to be an effective disintegration process for enhanced biodegradation and higher methane production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Disintegration of digested sludge is a promising technique for bioenergy generation. </LI> <LI> Floc dispersion was achieved at lesser disperser input energy of 9.5 kJ/kg TS. </LI> <LI> A higher lysate solubilization of 22.4% was achieved in floc dispersed sample. </LI> <LI> Biopolymer release of floc dispersed sludge was higher (1379.8 and 394.2 mg/L) </LI> <LI> Result of methane reveals the effect of floc dispersion prior to disintegration. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

In vitro Plant Regeneration from Apical Bud and Nodal Segments of Anthocepahalus Cadamba – An important sacred and medicinal tree

M Kavitha,Kalaimagal, S Mercy,N Sangeetha,D Ganesh 강원대학교 산림과학연구소 2009 Journal of Forest Science Vol.25 No.2

Multiple shoot induction and plant regeneration using apical bud and nodal explants of 100 year old tree of Anthocephalus cadamba, an important sacred and medicinal tree in India was achieved for the first time. Aseptic explants cultured in Murashige and Skoog (MS) medium augmented with different concentrations of BAP (0.1, 0.5, 1.0, 2.5, 5.0 and 10 mg/l), when maintained for 60 days, healthy shoots were induced in presence of BAP (1 mg/l). Lower concentrations of BAP (0.1 - 0.5 mg/l) induced only one shoot per explant. Increase in number of shoots per explant was observed in presence of higher concentrations of BAP (2.5, 5.0 and 10 mg/l). However, elongation of shoots was completely inhibited. Bud break and shoot regeneration was largely associated with seasonal factors. Apical buds cultured during June to August exhibited early bud break within two weeks of initial culture. In rest of the months, bud break and shoot regeneration was very slow irrespective of the various concentrations of BAP used in the medium. Explants sourced from three different maturity levels of shoots indicated that actively growing shoots from the mother plant with 1 – 2 nodal segments was more suitable for culture initiation than the explants collected from mature shoots at dormant stage. Regenerated shoots with 2 – 3 pairs of leaves when transferred to half strength MS medium fortified with IBA (1 mg/l), 60% of the shoots induced healthy roots, indicating the possibility of large scale micropropagation.

In vitro Plant Regeneration from Apical Bud and Nodal Segments of Anthocepahalus Cadamba - An important sacred and medicinal tree

Kavitha, M.,Kalaimagal, I.,Mercy, S.,Sangeetha, N.,Ganesh, D. Institute of Forest Science 2009 Journal of Forest Science Vol.25 No.2

Multiple shoot induction and plant regeneration using apical bud and nodal explants of 100 year old tree of Anthocephalus cadamba, an important sacred and medicinal tree in India was achieved for the first time. Aseptic explants cultured in Murashige and Skoog (MS) medium augmented with different concentrations of BAP (0.1, 0.5, 1.0, 2.5, 5.0 and 10 mg/l), when maintained for 60 days, healthy shoots were induced in presence of BAP (1 mg/l). Lower concentrations of BAP (0.1 - 0.5 mg/l) induced only one shoot per explant. Increase in number of shoots per explant was observed in presence of higher concentrations of BAP (2.5, 5.0 and 10 mg/l). However, elongation of shoots was completely inhibited. Bud break and shoot regeneration was largely associated with seasonal factors. Apical buds cultured during June to August exhibited early bud break within two weeks of initial culture. In rest of the months, bud break and shoot regeneration was very slow irrespective of the various concentrations of BAP used in the medium. Explants sourced from three different maturity levels of shoots indicated that actively growing shoots from the mother plant with 1 - 2 nodal segments was more suitable for culture initiation than the explants collected from mature shoots at dormant stage. Regenerated shoots with 2 - 3 pairs of leaves when transferred to half strength MS medium fortified with IBA (1 mg/l), 60% of the shoots induced healthy roots, indicating the possibility of large scale micropropagation.

Embedded System based Monitoring and Controlling of Parameters in Die Casting Industry

S.Thulasiram,Dr. N.Suthanthira Vanitha,M.Rajendiran,N.Kavitha 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.5

Die casting is the process for manufacturing the metal parts with desired shape for various industrial applications. Casting Process depends on many parameters variation such as die temperature, moisture level and viscosity of liquid level. At present days all the process parameters in die casting industry are measured manually. Manual measurement leads to error in measurement also time consuming. To overcome this issue non-contact type temperature measurement device is used for die temperature measurement but moisture and viscosity of the die is measured manually. Because die temperature is very sensitive one in die casting process. The proposed system is partially automated with PIC microcontroller and monitoring of the process is done through LabVIEW software.

Deposition of zinc–zinc phosphate composite coatings on steel by cathodic electrochemical treatment

Kavitha, C.,Sankara Narayanan, T. S.,Ravichandran, K.,Park, I. S.,Lee, M. H. Springer Science + Business Media 2014 Journal of coatings technology and research Vol.11 No.3

The present work aims at the development of an energy-efficient and eco-friendly approach for the deposition of zinc phosphate coatings on steel. The study describes the possibility of preparing zinc-zinc phosphate composite coatings by cathodic electrochemical treatment using dilute phosphoric acid as an electrolyte and zinc as an anode. The methodology enables the preparation of coatings with different proportions of zinc and zinc phosphate by suitably varying the applied current density, pH, and treatment time. Adhesion of the coating on mild steel and adhesion of paint film on the phosphate coating were found to be good. The surface morphology of the coatings exhibited platelet-type features and small white crystals (agglomerated at some places) which represented zinc and zinc phosphate, respectively. An increase in current density (from 20 to 50 mA/cm(2)) increased the size of the zinc crystals, and coatings prepared at 40 and 50 mA/cm(2) resembled that of electrodeposited zinc. Since the proportions of zinc and zinc phosphate could be varied with applied current density, pH, and treatment time, it would be possible to use this methodology to prepare coatings that would offer different degrees of corrosion protection.

Seismic behavior of steel and sisal fiber reinforced beam-column joint under cyclic loading

S.M. Kavitha,G. Venkatesan,Siva Avudaiappan,Chunwei Zhang 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.88 No.5

The past earthquakes revealed the importance of the design of moment-resisting reinforced concrete framed structures with ductile behavior. Due to seismic activity, failures in framed structures are widespread in beam-column joints. Hence, the joints must be designed to possess sufficient strength and stiffness. This paper investigates the effects of fibers on the ductility of hybrid fiber reinforced self-compacting concrete (HFRSCC) when subjected to seismic actions; overcoming bottlenecks at the beam-column joints has been studied by adding low modulus sisal fiber and high modulus steel fiber. For this, the optimized dose of hooked end steel fiber content (1.5%) was kept constant, and the sisal fiber content was varied at the rate of 0.1%, up to 0.3%. The seismic performance parameters, such as load-displacement behavior, ductility, energy absorption capacity, stiffness degradation, and energy dissipation capacity, were studied. The ductility factor and the cumulative energy dissipation capacity of the hybrid fiber (steel fiber, 1.5% and sisal fiber, 0.2%) added beam-column joint specimen is 100% and 121% greater than the control specimen, respectively. And also the stiffness of the hybrid fiber reinforced specimen is 100% higher than the control specimen. Thus, the test results showed that adding hybrid fibers instead of mono fibers could significantly enhance the seismic performance parameters. Therefore, the hybrid fiber reinforced concrete with 1.5% steel and 0.2% sisal fiber can be effectively used to design structures in seismic-prone areas.

Synergetic effect of combined pretreatment for energy efficient biogas generation

Kannah, R. Yukesh,Kavitha, S.,Rajesh Banu, J.,Yeom, Ick Tae,Johnson, M. Elsevier 2017 Bioresource technology Vol.232 No.-

<P><B>Abstract</B></P> <P>Physiochemical disintegration of waste activated biosolids (WAB) through thermochemical (TC) pretreatment requires high energy and cost for efficient energy generation. Therefore in the present study, an attempt has been made to enhance the biodegrdability and to minimize the operational cost of TC pretreatment by combining it with ozonation. A higher solubilization of about 30.4% was achieved at lesser energy input of about 141.02kJ/kgTS and a ozone dosage of about 0.0012mgO<SUB>3</SUB>/mgSS through this combined thermo chemo ozone (TCO<SUB>3</SUB>) pretreatment. The methane production potential (0.32gCOD/gCOD) of TCO<SUB>3</SUB> pretreatment was comparatively higher than the (0.19gCOD/gCOD) TC pretreatment. The energetic analysis and economic assessment of the proposed method of pretreatment can possibly reduces the energy requirement of TC pretreatment with a positive net profit of about 35.49$/ton of biosolids.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Combined TCO<SUB>3</SUB> pretreatment improves disintegration of WAB effectually. </LI> <LI> This novel method aid solubilization at lesser specific energy of 141.02kJ/kgTS. </LI> <LI> COD solubilization of about 30.4% was achieved in 0.0012mgO<SUB>3</SUB>/mgVS ozone dosage. </LI> <LI> Highest methane yield of 0.32gCOD/gCOD was observed in TCO<SUB>3</SUB> pretreated biosolids. </LI> <LI> Combinative pretreatment offers a net profit of about 35.49$/ton of WAB. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>