Improving the quality of runoff from green roofs through synergistic biosorption and phytoremediation techniques: A review

Vijayaraghavan, K.,Reddy, D. Harikishore Kumar,Yun, Yeoung-Sang Elsevier 2019 Sustainable cities and society Vol.46 No.-

<P><B>Abstract</B></P> <P>Urban rooftops covered with plants known as “green roofs” or “vegetative roofs” have recently attracted intense research interest because of their unique benefits and recognition in various countries as a potential best management practice. However, most of these benefits are just theoretical assumptions, and only few research efforts have been performed to draw a definitive conclusion. Of these, the quality of runoff from vegetative roofs often comes under debate. Hence, this critical review article primarily focuses on the quality of water from vegetative roofs, as well as directions to achieve better quality runoff. This review briefly introduces the fundamentals and benefits of vegetative roofs, followed by the quality of runoff as observed by other investigators. Until now, the vegetative roof substrate and plant types have not been selected based on their potential to decontaminate runoff. To improve the quality of runoff, we highlight the necessity to consider the sorption capacity of the substrate and phytoremediation potential of plants. For the first time, various sorbents that can be used as additives in the vegetative roof substrate, as well as practical plant species that can phytoextract contaminants in the substrate are presented. Some recommendations regarding the future research are also provided.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Quality of runoff generated from vegetative roofs was assessed. </LI> <LI> Growth substrate and plants influence the runoff quality of vegetative roofs. </LI> <LI> Substrate with high sorption and phytoremediation plants enhance runoff quality. </LI> </UL> </P>

Anaerobic Digestion and In situ Electrohydrolysis of Dairy Bio-sludge

Krishnan Vijayaraghavan,G. K. Sagar 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.3

A novel treatment method based on anaerobic digestion and in-situ electrohydrolysis of dairy bio-sludge was investigated in this article. The electrohydrolysis was carried out inside the anaerobic reactor using graphite anode and stainless steel cathode. The electrons released by the graphite anode combines with the proton released due to electrohydrolysis of fatty acids which resulted in the formation of hydrogen gas. The experiments were conducted using a DC power source under continuous and intermittent mode of input voltage ranging from 0.5 to 2.5 V for varying influent volatile solids concentration at a pH 5.3 ± 0.2. The results favored intermittent mode of input voltage rather than continuous supply. For an influent total solid concentration of 7% (64,120 mg/L VS), intermittent input voltage of 2 V, and a hydraulic retention time of 15 days resulted in a volatile solids and soluble COD removal efficiency of 83 and 74%, while the cumulative gas generation was 1,051 L with a hydrogen content of 72%.

Synthesis, characterization and application of cellulose/polyaniline nanocomposite for the treatment of simulated textile effluent

Janaki, V.,Vijayaraghavan, K.,Oh, Byung-Taek,Ramasamy, A. K.,Kamala-Kannan, Seralathan Springer-Verlag 2013 Cellulose Vol.20 No.3

Image Denoising with a Convolution Neural Network using Gaussian Filtered Residuals

Laavanya Mohan,Vijayaraghavan Veeramani 대한전자공학회 2021 IEIE Transactions on Smart Processing & Computing Vol.10 No.2

Deep learning using a convolutional neural network has become a state-of-art technique in image processing. In recent scenarios, image denoising using a residual image in deep learning has been popular. However, one aspect missing in these methods is that the residual image has all the noise and very small structured details of the input image. Therefore, we have developed a Gaussian filter residual convolutional neural network architecture for color image denoising. Gaussian residual learning was used to boost the denoising performance. The architecture is designed to remove additive white Gaussian noise, which is one of the most basic types of noise that affects an image when captured. The network with Gaussian residual learning removes the clean image using the features learned from the hidden layer. The peak signal-to-noise ratio and structural similarity index measure achieved by our method reveals that the presented approach is better at denoising images with Gaussian noise than a convolutional neural network.

Prediction of Temperature Distribution in the Workpiece during Multi-Pass Grinding by Finite Volume Method

Umamaheswari Madopothula,Vijayaraghavan, Lakshmanan,Ramesh Babu, Nimmagadda,Pradeev, Elango 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.11

The finite volume model is developed for multi-pass grinding by considering the grinding wheel and work contact zone as a rectangular shaped moving heat source with uniform heat distribution at a velocity equal to the feed rate. Though some literature dealt the thermal modelling of single pass grinding, in practical application multi-pass grinding is done in most of the industries to enhance the finish of work material. Modelling the temperature profile in multi-pass grinding is complex due to the heat from previous passes is carried out to the next pass. This heat accumulation from previous passes increase the peak flash temperature. Hence there is an urge to develop a thermal model which calculates the depth of heat affected zone for multi-pass grinding. The experimentally obtained grinding power is used in calculating the heat flux which replicates the condition of abrasive grains, work-wheel interaction and process behavior. For experimental validation, thermocouple is placed at a depth of 1.5mm below the grinding surface and temperature values are obtained as the material is ground till the wheel touches the thermocouple. The temperature distribution for multiple grinding passes on the work material at different depths and time, Peak temperature and the heat flux distribution. Manuscript

Management of Tuberculous Infection of the Spine

Pankaj Kandwal,Vijayaraghavan G.,Arvind Jayaswal 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Spinal tuberculosis accounts for nearly half of all cases of musculoskeletal tuberculosis. It is primarily a medical disease and treatment consists of a multidrug regimen for 9–12 months. Surgery is reserved for select cases of progressive deformity or where neurological deficit is not improved by anti-tubercular treatment. Technology refinements and improved surgical expertise have improved the operative treatment of spinal tuberculosis. The infected spine can be approached anteriorly or posteriorly, in a minimally invasive way. We review the various surgical techniques used in the management of spinal tuberculosis with focus on their indications and contraindications.

Biosorption of Tm(III) by free and polysulfone-immobilized Turbinaria conoides biomass

S. Rangabhashiyam,K. Vijayaraghavan 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

The current investigation focus on the use of brown alga Turbinaria conoides (TC) and polysulfoneimmobilized Turbinaria conoides (PITC) for the biosorption of rare earth element Thulium (Tm(III)) fromaqueous systems. To attain the highest removal of Tm(III), the process parameters including theequilibrium pH, Tm(III) concentration and biosorption time were optimized. The characterizationtechniques were used to analyse the morphological features and elemental analysis of the biosorbents. The isotherm models of selective two and three parameters were subjected to inspect the equilibriumdata. The biosorption datafitted to the different biosorption kinetic models. Results illustrated that bothTC and PITC displayed higher biosorption capacity of 200.5 and 157.9 mg/g, respectively. Through kinetictrials, we identified delay in equilibrium attainment for PITC and the data were described withintraparticle diffusion model. TC and PITC presented comparable results with biosorption equilibriumattained in 200 min, optimum equilibrium solution pH 5.0 and exhibited maximum biosorption capacityfor the initial Tm(III) concentrations of 500 mg/L. Recovery studies represented that the maximumdesorption efficiency attained using 0.01 M HCl and PITC presented potential uptake capacity of Tm(III)during the entire 10 biosorption–desorption cycles.

Pre-Operative Evaluation of Ovarian Tumors by Risk of Malignancy Index, CA125 and Ultrasound

Arun-Muthuvel, Veluswamy,Jaya, Vijayaraghavan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Purpose: To evaluate the diagnostic performances of risk of malignancy index (RMI), CA-125 and ultrasound score in differentiating between benign and borderline or malignant ovarian tumors and find the best diagnostic test for referral of suspected malignant ovarian cases to gynaecologic oncologists. Materials and Methods: This prospective study covered 467 women with pelvic tumors scheduled for surgery at our hospital between July 2011 and July 2013. The RMI was obtained from ultrasound score, CA125 and menopausal status. The diagnostic values of each parameter and the RMI were determined and compared using Statistical Packages for Social Sciences Version 14.0.1. Results: In our study, 61% of ovarian tumors were malignant in the post-menopausal age group. RMI with a cut-off 150 had sensitivity of 84% and specificity of 97% in detecting ovarian cancer. CA-125>30 had a sensitivity of 84% and a specificity of 83%. An ultrasound score more than 2 had a sensitivity of 96% and specificity of 81%. RMI had the least false malignant cases thus avoiding unnecessary laparotomies. Ultrasound when used individually had the best sensitivity but poor specificity. Conclusions: Our study has demonstrated the RMI to be an easy, simple and applicable method in the primary evaluation of patients with pelvic masses. It can be used to refer suspected malignant patients to be operated by a gynaecologic oncologist. Other models of preoperative evaluation should be developed to improve the detection of early stage invasive, borderline and non-epithelial ovarian cancers.

Severe Rigid Scoliosis: Review of Management Strategies and Role of Spinal Osteotomies

Pankaj Kandwal,Govindaraja Perumal Vijayaraghavan,Upendra Bidre Nagaraja,Arvind Jayaswal 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.3

Severe rigid curves pose a considerable challenge to the treating spine surgeon. In our practice, approximately 30%–40% of patients with scoliosis present late with severe rigid scoliosis (>90° and <30% correction on bending films). Controversy still exists with regard to the ideal surgical strategy for correcting these rigid curves. Rigid scoliosis often presents in the form of either sharp angular or rounded deformities. Rounded deformities can be effectively managed with an anterior release to loosen the apex and posterior instrumentation (with osteotomies, if required). In contrast, severe rigid scoliosis, which is a sharp angular deformity, is not very amenable to anterior release and is best managed by posterior-only vertebral column resection and posterior instrumentation.

A phosphorus-enriched biochar fertilizer from bio-fermentation waste: A potential alternative source for phosphorus fertilizers

Kim, Jeong Ae,Vijayaraghavan, K.,Reddy, D. Harikishore Kumar,Yun, Yeoung-Sang Elsevier 2018 Journal of cleaner production Vol.196 No.-

<P><B>Abstract</B></P> <P>It is necessary to explore alternative resources for phosphorus (P) in an effort to address the lack of available P source for crops in an agricultural sector. In this study, bacterial biomass waste of <I>Escherichia coli</I> from a fermentation industry was converted to “P-enriched biochar”, and its possibility as a P fertilizer was assessed. Biochar yields (5.2 ± 0.74% to 19.7 ± 1.54%) highly depended on pyrolysis conditions such as initial weight of feedstock and residence time. Inorganic elemental analysis revealed that the biochar did not consist of any elements with high toxic concentration levels regardless of its yield and that it was rich in P. Biochar with lower yield showed higher water soluble P. Subsequently, a rapid P-release in water and citric acid was initially observed, and a gradual decline one day later was followed. The extractable P in water and citric acid reached 52% and 61%, respectively, of initial P content (84.7 mg g<SUP>−1</SUP>) in the biochar in five days. Scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) results showed that P was evenly distributed in macropore-sized biochar matrix, and the contents of P and O decreased after P release into water. Fourier transform infrared spectroscopy (FT-IR) revealed that the peaks related to phosphate form significantly decreased after P release. SEM-EDS and FT-IR results indicated that released form of P was phosphate. Hydroculture bioassay showed that biochar had a positive effect on the early growth of <I>Lactuca sativa</I>. This study suggested that conversion of bacterial waste to the P-enriched biochar could be a feasible strategy for recycling P source as a P fertilizer as well as valorization of wastes from fermentation industry.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bacterial biomass waste from fermentation industry was directly converted to phosphorus-enriched biochar. </LI> <LI> The contents of toxic chemicals were negligible for application to soil. </LI> <LI> Slow release of phosphorus from the biochar was found in water and citric acid. </LI> <LI> The resulting biochar promoted early growth of lettuce. </LI> </UL> </P>