Selecting optimized mix proportion of bagasse ash blended high performance concrete using analytical hierarchy process (AHP)

S. Praveenkumar,G. Sankarasubramanian,S. Sindhu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.6

Apart from strength properties, durability, toughness and workability are also important criteria in defining the performance of a concrete structure. Hence “High Performance Concrete (HPC)” is introduced. It is different from high strength concrete and can have various applications. In this paper, the properties (Mechanical and Durability) of High Performance Concrete blended with bagasse ash at 5%, 10%, 15% and 20% are studied. However, it is difficult to analyze the performance based on different properties obtained from different experiments. Hence it is necessary to combine all the criteria/properties into a single value to obtain a result by a technique called Analytical Hierarchy Process (AHP).It is an effective tool for dealing with complex decision making, and may aid the decision maker to set priorities and make the best decision. In addition, the AHP incorporates a useful technique for checking the consistency of the decision maker‟s evaluations, thus reducing the bias in the decision making process.

Magnetophoretic harvesting of oleaginous Chlorella sp. by using biocompatible chitosan/magnetic nanoparticle composites

Lee, K.,Lee, S.Y.,Na, J.G.,Jeon, S.G.,Praveenkumar, R.,Kim, D.M.,Chang, W.S.,Oh, Y.K. Elsevier Applied Science 2013 Bioresource technology Vol.149 No.-

The consumption of energy and resources such as water in the cultivation and harvesting steps should be minimized to reduce the overall cost of biodiesel production from microalgae. Here we present a biocompatible and rapid magnetophoretic harvesting process of oleaginous microalgae by using chitosan-Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticle composites. Over 99% of microalgae was harvested by using the composites and the external magnetic field without changing the pH of culture medium so that it may be reused for microalgal culture without adverse effect on the cell growth. Depending on the working volume (20-500mL) and the strength of surface magnetic-field (3400-9200G), the process of harvesting microalgae took only 2-5min. The method presented here not only utilizes permanent magnets without additional energy for fast harvesting but also recycles the medium effectively for further cultivation of microalgae, looking ahead to a large scale economic microalgae-based biorefinement.

Mild pressure induces rapid accumulation of neutral lipid (triacylglycerol) in Chlorella spp.

Praveenkumar, R.,Kim, B.,Lee, J.,Vijayan, D.,Lee, K.,Nam, B.,Jeon, S.G.,Kim, D.M.,Oh, Y.K. Elsevier Applied Science 2016 Bioresource technology Vol.220 No.-

Effective enhancement of neutral lipid (especially triacylglycerol, TAG) content in microalgae is an important issue for commercialization of microalgal biorefineries. Pressure is a key physical factor affecting the morphological, physiological, and biochemical behaviors of organisms. In this paper, we report a new stress-based method for induction of TAG accumulation in microalgae (specifically, Chlorella sp. KR-1 and Ch. sp. AG20150) by very-short-duration application of mild pressure. Pressure treatments of 10-15bar for 2h resulted in a considerable, ~55% improvement of the 10-100g/Lcells' TAG contents compared with the untreated control. The post-pressure-treatment increase of cytoplasmic TAG granules was further confirmed by transmission electron microscopy (TEM). Notwithstanding the increased TAG content, the total lipid content was not changed by pressurization, implying that pressure stress possibly induces rapid remodeling/transformation of algal lipids rather than de novo biosynthesis of TAG.

Comparison of User-generated Tags with Subject Descriptors, Author Keywords, and Title Terms of Scholarly Journal Articles: A Case Study of Marine Science

Vaidya, Praveenkumar,Harinarayana, N.S. Korea Institute of Science and Technology Informat 2019 Journal of Information Science Theory and Practice Vol.7 No.1

Information retrieval is the challenge of the Web 2.0 world. The experiment of knowledge organisation in the context of abundant information available from various sources proves a major hurdle in obtaining information retrieval with greater precision and recall. The fast-changing landscape of information organisation through social networking sites at a personal level creates a world of opportunities for data scientists and also library professionals to assimilate the social data with expert created data. Thus, folksonomies or social tags play a vital role in information organisation and retrieval. The comparison of these user-created tags with expert-created index terms, author keywords and title words, will throw light on the differentiation between these sets of data. Such comparative studies show revelation of a new set of terms to enhance subject access and reflect the extent of similarity between user-generated tags and other set of terms. The CiteULike tags extracted from 5,150 scholarly journal articles in marine science were compared with corresponding Aquatic Science and Fisheries Abstracts descriptors, author keywords, and title terms. The Jaccard similarity coefficient method was employed to compare the social tags with the above mentioned wordsets, and results proved the presence of user-generated keywords in Aquatic Science and Fisheries Abstracts descriptors, author keywords, and title words. While using information retrieval techniques like stemmer and lemmatization, the results were found to enhance keywords to subject access.

Cell-wall disruption and lipid/astaxanthin extraction from microalgae: Chlorella and Haematococcus

Kim, D.Y.,Vijayan, D.,Praveenkumar, R.,Han, J.I.,Lee, K.,Park, J.Y.,Chang, W.S.,Lee, J.S.,Oh, Y.K. Elsevier Applied Science 2016 Bioresource technology Vol.199 No.-

Recently, biofuels and nutraceuticals produced from microalgae have emerged as major interests, resulting in intensive research of the microalgal biorefinery process. In this paper, recent developments in cell-wall disruption and extraction methods are reviewed, focusing on lipid and astaxanthin production from the biotechnologically important microalgae Chlorella and Haematococcus, respectively. As a common, critical bottleneck for recovery of intracellular components such as lipid and astaxanthin from these microalgae, the composition and structure of rigid, thick cell-walls were analyzed. Various chemical, physical, physico-chemical, and biological methods applied for cell-wall breakage and lipid/astaxanthin extraction from Chlorella and Haematococcus are discussed in detail and compared based on efficiency, energy consumption, type and dosage of solvent, biomass concentration and status (wet/dried), toxicity, scalability, and synergistic combinations. This report could serve as a useful guide to the implementation of practical downstream processes for recovery of valuable products from microalgae including Chlorella and Haematococcus.

Lesion-Wise Comparison of Pre-Therapy and Post-Therapy Effective Half-Life of Iodine-131 in Pediatric and Young Adult Patients with Differentiated Thyroid Cancer Undergoing Radioiodine Therapy

Praveen Kumar,Chandrasekhar Bal,Nishikant Avinash Damle,Sanjana Ballal,S. N. Dwivedi,Sandeep Agarwala 대한핵의학회 2019 핵의학 분자영상 Vol.53 No.3

Purpose The effective half-life of radioiodine is an important parameter for dosimetry in differentiated thyroid cancer patients, particularly in children. We determined the pre-therapy and post-therapy effective half-life in different types of lesions, i.e., remnant, node, or lung metastases. Methods Of 84 patients recruited, 27 were < 18 years (group 1) and the remaining 57 were between 18 and 21 years (group 2). A total of 114 studies were conducted and 253 lesions were analyzed. Serial whole-body scans were acquired at 24, 48, and ≥ 72 h after administration of iodine-131. Region of interests was drawn over lesions to determine counts in the lesion. Time versus counts graphs were plotted and mono-exponentially fitted to determine effective half-life. Results The post-therapy effective half-life was found to be lesser than pre-therapy effective half-life in all types of lesions and in all groups. Median effective half-life was found maximum in intact lobe, minimum in the lung, and intermediate in remnant and nodes. In the assessment of all lesions together, pre- and post-therapy median and interquartile range (IQR) effective half-life were 59.8 (37–112) h and 48.6 (35.2–70.8) h (p < 0.0001) in group 1, 73.9 (46.2–112.7) h and 60 (57.4–85.9) h (p < 0.0001) in group 2, and 68.6 (41.53–112.36) h and 54.7 (36–80.6) h (p < 0.0001) in combined group, respectively. Importantly, the pre- and post-therapy median effective half-life serially dropped after each successive cycles of iodine-131. Conclusions There was a significant difference in pre-therapy and post-therapy effective half-life in all types of lesions. These results may have implications in calculating the correct therapeutic dose in children and in young adults.