Application of time series based damage detection algorithms to the benchmark experiment at the National Center for Research on Earthquake Engineering (NCREE) in Taipei, Taiwan

Hae Young Noh,Krishnan Nair,Anne S. Kiremidjian,C-H. Loh 국제구조공학회 2009 Smart Structures and Systems, An International Jou Vol.5 No.1

In this paper, the time series based damage detection algorithms developed by Nair, et al. (2006) and Nair and Kiremidjian (2007) are applied to the benchmark experimental data from the National Center for Research on Earthquake Engineering (NCREE) in Taipei, Taiwan. Both acceleration and strain data are analyzed. The data are modeled as autoregressive (AR) processes, and damage sensitive features (DSF) and feature vectors are defined in terms of the first three AR coefficients. In the first algorithm developed by Nair, et al. (2006), hypothesis tests using the t-statistic are applied to evaluate the damaged state. A damage measure (DM) is defined to measure the damage extent. The results show that the DSF’s from the acceleration data can detect damage while the DSF from the strain data can be used to localize the damage. The DM can be used for damage quantification. In the second algorithm developed by Nair and Kiremidjian (2007) a Gaussian Mixture Model (GMM) is used to model the feature vector, and the Mahalanobis distance is defined to measure damage extent. Additional distance measures are defined and applied in this paper to quantify damage. The results show that damage measures can be used to detect, quantify, and localize the damage for the high intensity and the bidirectional loading cases.

Application of time series based damage detection algorithms to the benchmark experiment at the National Center for Research on Earthquake Engineering (NCREE) in Taipei, Taiwan

Noh, Hae Young,Nair, Krishnan K.,Kiremidjian, Anne S.,Loh, C.H. Techno-Press 2009 Smart Structures and Systems, An International Jou Vol.5 No.1

In this paper, the time series based damage detection algorithms developed by Nair, et al. (2006) and Nair and Kiremidjian (2007) are applied to the benchmark experimental data from the National Center for Research on Earthquake Engineering (NCREE) in Taipei, Taiwan. Both acceleration and strain data are analyzed. The data are modeled as autoregressive (AR) processes, and damage sensitive features (DSF) and feature vectors are defined in terms of the first three AR coefficients. In the first algorithm developed by Nair, et al. (2006), hypothesis tests using the t-statistic are applied to evaluate the damaged state. A damage measure (DM) is defined to measure the damage extent. The results show that the DSF's from the acceleration data can detect damage while the DSF from the strain data can be used to localize the damage. The DM can be used for damage quantification. In the second algorithm developed by Nair and Kiremidjian (2007) a Gaussian Mixture Model (GMM) is used to model the feature vector, and the Mahalanobis distance is defined to measure damage extent. Additional distance measures are defined and applied in this paper to quantify damage. The results show that damage measures can be used to detect, quantify, and localize the damage for the high intensity and the bidirectional loading cases.

Improvement in the Commercial Traits of Silkworm, Bombyx mori L. by Administration of a Juvenoid, R394

Nair, K.Sashindran,Vijayan, V.A,,Trivedy, Kanika,Nair, Jula S. Korean Society of Sericultural Science 2001 International Journal of Industrial Entomology Vol.3 No.2

A synthetic juvenoid, R394 (Ethyl 9-cyclohexyl-3, 7-dimethyl-2, 4-nonadienoate) which is known to be a strong pest control agent was administered to silkworm, Bombyx mori L. in minute quantity for improving the silk yield. Based on the result of an earlier preliminary screening, three concentrations of the compound, viz., 0.1563, 0.3125, 31.25 nl/ml were prepared in the form of an emulsion and administered topically as a single dose, to separate batches of $5^{th}$ instar silkworm at 24, 48, 72 and 96 hrs to determine the required concentration and critical time of application for an economically favourable response. Two popular commercial silkworm hybrids, PM ${\times}$ NB4D2 (multivoltine${\times}$bivoltine) and KA${\times}$NB4D2 (bivoltine$\times$bivoltine) were subjected to the experiment. The medium and absolute control were maintained in parallel to compare the results. The results showed that 0.3125 nl/ml was the best concentration of the compound and 72 hrs of $5^{th}$instar was the most favourable age for its administration to get the maximum improvement in the commercial traits. The possible role of exogenous juvenoids in eliciting favourable response in silkworm which ultimately leads to improvement in the commercial traits is discussed.

THYROID ULTRASOUND : A REVIEW OF 405 CASES

Ramachandran Nair Parameswaran,Pradeep,Nair, Krishnan 대한핵의학회 1984 핵의학 분자영상 Vol.18 No.1

Improvement in the Commercial Traits of Silkworm, Bombyx mori L. by Administration of a Juvenoid, R394

( K. Sashindran Nair ),( V. A. Vijayan ),( Kanika Trivedy ),( Jula S. Nair ) 한국잠사학회 2001 International Journal of Industrial Entomology Vol.3 No.2

A synthetic juvenoid, R394 (Ethyl 9-cyclohexyl-3, 7-dimethyl-2, 4-nonadienoate) which is known to be a strong pest control agent was administered to silkworm, Bombyx mori L. in minute quantity for improving the silk yield. Based on the result of an earlier preliminary screening, three concentrations of the compound, viz., 0.1563, 0.3125, 31.25 nl/ml were prepared in the form of an emulsion and administered topically as a single dose, to separate batches of 5th instar silkworm at 24, 48, 72 and 96 hrs to determine the required concentration and critical time of application for an economically favourable response. Two popular commercial silkworm hybrids, PM×NB4D2 (multivoltine×bivoltine) and KA×NB4D2 (bivoltine×bivoltine) were subjected to the experiment. The medium and absolute control were maintained in parallel to compare the results. The results showed that 0.3125 nl/ml was the best concentration of the compound and 72 hrs of 5th instar was the most favourable age for its administration to get the maximum improvement in the commercial traits. The possible role of exogenous juvenoids in eliciting favourable response in silkworm which ultimately leads to improvement in the commercial traits is discussed.

ACUTE INTERMITTENT PORPHYRIA AND HYPER THYROIDISM : A CASE REPORT

Parameswaran, Ramachandran Nair,Pradeep,Nair, Krishnan 대한핵의학회 1984 핵의학 분자영상 Vol.18 No.1

1, 25-(OH)2D3 protects against ER stress and miRNA dysregulation in Mus musculus neurons

Jayachandran Parvathy,Koshy Linda,Sudhakaran Perumana R.,Nair Govindapillai Mohanadasan,Gangaprasad Appukuttan Nair,Nair Ananthakrishnan Jayakumaran 한국유전학회 2022 Genes & Genomics Vol.44 No.12

Background: The pathophysiology of neurodegenerative diseases (NDDs) is closely associated with cellular oxidative stress which can result in the accumulation of toxic proteins in the endoplasmic reticulum (ER) leading to ER stress and subsequent unfolded protein response (UPR) signaling, a mechanism that aggravate these disorders. Vitamin D has been suggested to have important neuroprotective role and its administration has been shown to reduce neuronal injury, neurotoxicity and oxidative stress in various animal systems. Objective: The current study was undertaken to examine the effect of vitamin D3 on UPR in ER stress induced Mus musculus neuronal cells. Methods: Mus musculus cortical and hippocampal primary neuronal cultures were pretreated with 1,25-dihydroxyvitamin D3 (1, 25-(OH)2D3), the active form of vitamin D, followed by ER stress induction with a chemical ER stress inducer thapsigargin and with an advanced glycated protein, AGE-BSA. The UPR genes and related microRNAs (miRNA) expressions were analyzed mainly using real-time PCR. Results: The experiment resulted in the suppression of ER stress marker BiP and UPR pathway genes such as Perk, Ire1α, Chop and Puma which mediate cellular apoptosis indicating the protective effect of 1, 25-(OH)2D3 against neuronal ER stress. Further studies into the molecular aspects showed that ER stress mediated down-regulated expression of microRNAs (miRNAs) such as mmu-miR-24, 27b, 124, 224, 290, 351 and 488 which are known to regulate the UPR pathway genes were also reduced with vitamin pretreatment, of which the miRNAs miR-24 and 27b which shares the same cluster are potentially involved in various human diseases. Conclusion: This study emphasizes the therapeutic role of vitamin D in reducing neuronal ER stress and the need for maintaining sufficient amount of this vitamin in our diet.

Regulation of morphological, molecular and nutrient status in <i>Arabidopsis thaliana</i> seedlings in response to ZnO nanoparticles and Zn ion exposure

Nair, Prakash M. Gopalakrishnan,Chung, Ill Min Elsevier BV 2017 Science of the Total Environment Vol.575 No.-

<P><B>Abstract</B></P> <P>This study examined the mechanism of toxicity in <I>Arabidopsis thaliana</I> seedlings to zinc oxide nanoparticles (ZnO NPs) and zinc (Zn) ions. We subjected plants to different ZnO NPs and Zn ion concentrations (0, 20, 50, 100 and 200mg/L) and analyzed resulting morphological changes, transcriptional regulation of genes involved in Zn-homeostasis, macro- and microelement homeostasis, as well as auxin regulation. Except for 20mg/L, the fresh weight and primary root length was reduced after exposure to all other concentrations of Zn ion and ZnO NP concentrations. An increase in lateral root formation (19 and 32%) was observed after exposure to 20 and 50mg/L of Zn ions respectively; whereas 20mg/L ZnO NPs treatment triggered a 9% increase in lateral root formation. Both qualitative, using Zynpyr-1 fluorescent probe and quantitative analysis revealed Zn uptake and translocation from roots to shoots after Zn ion exposure. However, ZnO NPs-treated seedlings resulted in no root to shoot translocation and Zn accumulation was mainly located in root tips, primary-lateral root junctions and root- shoot junctions. The macronutrients viz. P (1.34mg/kg DW), K (13.29mg/kg DW), S (1.29mg/kg DW) and micronutrients Cu (0.004mg/kg DW) and Fe (0.345mg/kg DW) contents were highly decreased as a result of exposure to 200mg/L of Zn ions. Similarly, the highest reduction of P (2.30mg/kg DW), K (6.36mg/kg DW), S (2.63mg/kg DW) and Cu (0.004mg/kg DW) was observed after exposure to 200mg/L of ZnO NPs. Gene regulation studies indicated the transcriptional modulation of various genes involved in Zn, macro- and micro nutrient homeostasis as well as hormone regulation. Taken together, it was observed that the mechanism of toxicity of Zn ions and ZnO NPs were different. These findings will help to design safer strategies for the application of ZnO NPs as plant fertilizer without compromising the morphological and nutritional qualities as well as for the future phytoremediation purposes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ZnO NPs and Zn ions induced morphological changes in <I>Arabidopsis thaliana</I>. </LI> <LI> Changes in roots system architecture was observed. </LI> <LI> Modulated the expression of metal homeostasis and hormone regulation genes </LI> <LI> Changed macro- and micro-nutrient contents </LI> <LI> Provides insights for future application of ZnO NPs as fertilizer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Growth and Nutrient Utilization in Buffalo Calves Fed Urea-ammoniated Wheat Straw and Hydrochloric Acid plus Urea Treated Wheat Straw

Nair, P.V.,Verma, A.K.,Dass, R.S.,Mehra, U.R. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.5

Ten growing male buffalo calves (aged 6-8 months, average body weight $88.2{\pm}0.57$ kg were divided randomly into two groups. Animals in group I were fed on concentrate mixture A (CP 20.2%, TDN 77.4%) and urea- ammoniated wheat straw (UAWS) while the animals in group II were fed on concentrate mixture B (CP 17.9%, TDN 77.6%) and HCl plus urea treated wheat straw (HCl UAWS) to meet their nutrient requirement for 500 g gain/d as per Kearl (1982). This feeding practice lasted for 120 days, during which fortnightly body weight were recorded to assess their growth rate. A metabolism trial was conducted after 90 days of experimental feeding to compare the digestibility of nutrients, their balance, plane of nutrition and relative cost of feeding in two groups of animals. Results revealed a significant increase in the CP content of ammoniated wheat straw due to addition of HCl viz 12.1% from 7.5%. There was a decrease in the intake of DM (p<0.05), OM (p<0.05), EE (p<0.05), NDF (p<0.01), ADF (p<0.01), cellulose (p<0.01) and hemicellulose (p<0.01) in group II as compared to group I. The digestibility (%) of DM, OM and CP was significantly (p<0.01) more in group II, whereas the digestibility (%) was significantly more for NDF (p<0.05) and hemicellulose (p<0.01) in group I than group II. There was no significant difference in the N, Ca and P balance in two groups. Intake of total DM (g/d) or (g/kg $W^{0.75}$) was significantly (p<0.01) more in group I as compared to group II, whereas the intake of DCP and TDN (g/d or g/kg $W^{0.75}$) was alike in two groups. The total body weight gain (kg), average daily gain (g/d) and feed conversion efficiency were significantly (p<0.01) more in UAWS fed group as compared to HCl UAWS fed group. Feeding cost (Rs./kg. weight gain) was significantly (p<0.05) more in group II as compared to group I. It is concluded that HCl UAWS is not suitable for the feeding of growing buffalo calves as it reduced the growth rate in comparison to UAWS fed buffalo calves.

Taming of large diameter triaxial setup

Nair, Asha M.,Madhavi Latha, G. Techno-Press 2012 Geomechanics & engineering Vol.4 No.4

Triaxial tests are essential to estimate the shear strength properties of the soil or rock. Normally triaxial tests are carried out on samples of 38 mm diameter and 76 mm height. Granular materials, predominantly used in base/sub-base construction of pavements or in railways have size range of 60-75 mm. Determination of shear strength parameters of those materials can be made possible only through triaxial tests on large diameter samples. This paper describes a large diameter cyclic triaxial testing facility set up in the Geotechnical Engineering lab of Indian Institute of Science. This setup consists of 100 kN capacity dynamic loading frame, which facilitates testing of samples of up to 300 mm diameter and 600 mm height. The loading ram can be actuated up to a maximum frequency of 10 Hz, with maximum amplitude of 100 mm. The setup is capable of carrying out static as well as dynamic triaxial tests under isotropic, anisotropic conditions with a maximum confining pressure of 1 MPa. Working with this setup is a difficult task because of the size of the sample. In this paper, a detailed discussion on the various problems encountered during the initial testing using the equipment, the ideas and solutions adopted to solve them are presented. Pilot experiments on granular sub-base material of 53 mm down size are also presented.