Seasonal distribution of microplastics in surface waters of the Northern Indian Ocean

Seven expeditions were carried out during pre-monsoon, monsoon and post monsoon in 2018-2019 for marine plastic collection in surface waters of Northern Indian Ocean. PE and PP (83 %) is the dominant type of polymer found in the surface waters. Colored particles account for 67 % of all particles, with fibre/line accounting for 86 %. The average (Mean ± SD) microplastics concentration in the Northern Indian Ocean during pre-monsoon is 15,200 ± 7999 no./km², Monsoon is 18,223 ± 14,725 no./km² and post monsoon is 72,381 ± 77,692 no./km². BoB during pre-monsoon and post monsoon the microplastic concentration remains same except in the northern BoB this change is caused due to weak winds. Microplastics concentration varied both spatially, temporal and heterogeneity in nature. These differences are caused by effect of wind and seasonal reversal of currents. Microplastics collected in the anticyclonic eddy are 129,000 no./km².

High prevalence of asymptomatic left ventricular diastolic dysfunction and its detection among South Asian patients with Type 2 Diabetes Mellitus compared with White Europeans

Background

Heart failure (HF) is an important manifestation of Type 2 Diabetes (T2D). The development of HF in T2D may be preceded by Stage B HF. Asymptomatic left ventricular impairment, especially left ventricular diastolic dysfunction (LVDD), is a defining early feature of Stage B HF. Detection of Stage B HF is crucial as it provides an opportune target for intervention with cardio-protective therapy to prevent the development of symptomatic HF in T2D. The risk of T2DM is higher in South Asian populations resulting in increased risk of macrovascular and microvascular complications. The prevalence of Stage B HF in South Asian patients with T2DM is not known.

Purpose

(i) To compare the prevalence of Stage B HF in South Asians in India compared with White Europeans in Scotland; (ii) To test the role of NT-proBNP in identifying Stage B HF

Methods

This study involved the comparison between two independently conducted, cross-sectional studies. The patients were asymptomatic patients with T2DM with no prior history of cardiovascular disease from Chennai, India (n=246) and Tayside, Scotland (n=246). All patients underwent transthoracic echocardiogram (echo) examination to detect the presence of structural and functional echo features of Stage B HF: left atrial enlargement (LAE), left ventricular hypertrophy (LVH), LVDD and LV systolic dysfunction (LVSD). Receiver operating curves (ROC) were used to determine the predictive ability of NT-proBNP to predict LAE/LVDD/LVD/LVSD.

Results

The prevalence of Stage B HF was high in South-Asian patients with T2DM (median age of 55 [49, 62] with a high prevalence of LVDD (5% had LVH, 7.3% had LAE, 70% had LVDD and 0% had LVSD (Figure 1B). 10% of the South Asian patients had at least 2 factors contributing to Stage B HF and these patients had higher NT-proBNP titres (703.4 [500.0, 949.2] vs 423.7 [35.0, 754.2], p<0.001). ROC curves show that NT-proBNP can predict these participants with 2 or more echo features [Figure 2B, AUC: 0.7043 (0.6159, 0.7928) p<0.05]. The prevalence of Stage B HF among White Europeans (median age of 67 [61, 72].) was lower compared with South Asian patients: 15% had LVH, 13% had LAE, 19% had LVDD and 2% had LVSD (Figure 1A). 8% of White Europeans had at least 2 factors contributing to Stage B HF and these had higher NT-proBNP titres (368.9 [154.6, 1087.8] vs 186.8 [79.7, 411.5], p=0.02). ROC curves show that NT-proBNP can predict participants with 2 or more factors [Figure 2A, AUC: 0.6399 (0.5122, 0.7676) p<0.05].

Conclusion

Our study has shown that South Asian patients with T2DM have a high prevalence of Stage B HF compared with White Europeans and that the predominant Stage B HF feature is LVDD.

We also found that NTproBNP could potentially be used to detect Stage B HF and help identify at-risk patients for cardio-protective therapy such as SGLT2 inhibitor therapy that has been shown to prevent the development of future HF events.

Funding Acknowledgement

Type of funding sources: None.

Seasonal temperature variability observed at abyssal depths in the Arabian Sea

The abyssal ocean is generally considered an aseasonal environment decoupled from the variabilities observed at and just below the ocean's surface. Herein, we describe the first in-situ timeseries record of seasonal warming and cooling in the Arabian Sea at a depth of 4000 m. The seasonal cycle was observed over the nearly four-year-long record (from November 2018 to March 2022). The abyssal seasonal temperature cycle also exhibited noticeable interannual variability. We investigate whether or not surface processes influence the near-seabed temperature through deep meridional overturning circulation modulated by the Indian monsoon or by Rossby wave propagation. We also consider if bottom water circulation variability and discharge of the dense Persian Gulf and Red Sea Water may contribute to the observed seasonality.

Spatial and seasonal variations in coastal water characteristics at Kalpakkam, western Bay of Bengal, Southeast India: a multivariate statistical approach

A study was carried out in the coastal waters of Kalpakkam with the objectives to evaluate the seasonality in hydrobiological parameters in surface and bottom waters, and assess the anthropogenic stress and monsoonal flux on a spatiotemporal scale. The study covered an area of approximately 100 km² in the coastal environment. Relatively high values for pH, temperature, and TP were observed during the post-monsoon (POM) season. The monsoon (MON) season was linked with TN, ammonia, and DO concentrations as all these parameters have shown increased values during this season due to freshwater input. The summer (SUM) season was characterized by salinity, turbidity, nitrate, phosphate, and silicate, indicating a true marine environmental condition for plankton production. Principal component analysis (PCA) and cluster analysis (CA) indicated the presence of distinct coastal water masses with respect to seasons and sampling regions. The spatial pattern indicated the distinctness of the coastal nearshore water (CNW) and coastal offshore water (COW) with respect to water quality. The CNW was more dynamic due to direct external influence as compared to the relatively stable COW environment. Similarly, the study region in the northern part, which is continuously exposed to the backwater inputs and tourism activities, was statistically different from the southern part.

Multiple Sensory Modalities in Diurnal Geckos Is Associated with the Signaling Environment and Evolutionary Constraints

To be effective, animal signals need to be detectable in the environment, but their development and expression require resources. For multimodal communication, investment in elaborating traits in one modality could reduce the elaboration of traits in other modalities. In Cnemaspis geckos, chemical signals for conspecific communication pre-dated the evolution of visual signals, allowing us to examine the potential trade-off in signal elaboration and the current habitat associations with signal use. We studied five species of Cnemaspis and quantified visual (patch size, color characteristics) and chemical (secretory composition) traits in males, as well as key environmental parameters (temperature, humidity, light) in each of their habitats. Within species, we found some trade-off in the elaboration of signals, as the strength of several components in the visual and chemical modalities were negatively associated. Strength of some signal components in each modality was also independently associated with specific environmental parameters that affect their detection (visual traits) and persistence (chemical traits). Specifically, species with larger, brighter, and more saturated color patches were found in habitats where the brightness and chroma of light were lower. Furthermore, environments with higher substrate temperature and higher relative humidity harbored species that produced secretions with a higher percentage of saturated and aromatic compounds. Thus, the elaboration of multimodal signals in this group of Cnemaspis geckos seems to increase the efficiency of communication in the signaling-environment, but the strength of signals in different modalities is constrained by trade-offs in signal expression.

White blood cell detection and classification using Euler’s Jenks optimized multinomial logistic neural networks

Due to the wide acceptance of White Blood Cells (WBCs) in disease diagnosis, detection and classification of WBC are hot topic. Existing methodologies have some drawbacks such as significant degree of error, higher accuracy, time bound and higher misclassification rate. A WBCs detection and classification called, Jenks Optimized Logistic Convolutional Neural Network (JO-LCNN) method has proposed. Initally, Eulers Principal Axis is used as a convolution model to obtain a rotation invariant form of image by differentiating the background and RBCs, then eliminating them which leaves only the WBCs. By eliminating the wanton features, inherent features are detected contributing to minimum misclassification rate. According to above, Jenks Optimization function is used as a pooling model to obtain feature map for lower resolution. Therefore JO-LCNN is used for removing tiny objects in image and complete nuclei. Finally, Multinomial Logistic classifier is used to classify five types of classes by means of loss function and updating weight according to the loss function, therefore classifying with higher accuracy rate. Using LISC database for WBCs with different parameters as classification accuracy, false positive rate and time complexity are performed. Result shows that JO-LCNN, efficiently improves accuracy with less time, misclassification rate than the state-of-art methods.

Structural and morphological data of RF-Sputtered BiVO4 thin films

Structural and morphological modulation of rf-sputtered BiVO₄ thin films deposited using mechanochemical synthesis prepared BiVO₄ nano-powders as sintered target are included in this data article. The crystalline nature of as-prepared films, namely amorphous and crystalline was acquired with time and temperature dependent in-situ high temperature X-ray diffraction (HT-XRD), at a time interval of 1 h. Typical Fourier transform infrared (FT-IR) spectra of annealed thin film of monoclinic BiVO₄ structure is given. Furthermore, correlation between morphologies of various substrate temperature fabricated BiVO₄ thin films are presented.

Optimization of Process Parameters of Pulsed Electro Deposition Technique for Nanocrystalline Nickel Coating Using Gray Relational Analysis (GRA)

The moving parts of any mechanism and machine parts are always subjected to a significant wear due to the development of friction. It is an utmost important aspect to address the wear problems in present environment. But the complexity goes on increasing to replace the worn out parts if they are very precise. Technology advancement in surface engineering ensures the minimum surface wear with the introduction of polycrystalline nano nickel coating. The enhanced tribological property of the nano nickel coating was achieved by the development of grain size and hardness of the surface. In this study, it has been decided to focus on the optimized parameters of the pulsed electro deposition to develop such a coating. Taguchi’s method coupled gray relational analysis was employed by considering the pulse frequency, average current density and duty cycle as the chief process parameters. The grain size and hardness were considered as responses. Totally, nine experiments were conducted as per L9 design of experiment. Additionally, response graph method has been applied to determine the most significant parameter to influence both the responses. In order to improve the degree of validation, confirmation test and predicted gray grade were carried out with the optimized parameters. It has been observed that there was significant improvement in gray grade for the optimal parameters.

Evaluation to prevent the Physical Changes in Colored Elastomeric Modules when exposed to various Dietary Media

AIM AND OBJECTIVE

The aim of the study is to analyze and compare the variation of lumen size and thickness of the elastomeric colored modules when immersed in four selected dietary media.

MATERIALS AND METHODS

Sample size of 40 modules on each color - such as red, blue, green, and black - was taken and immersed in four dietary media (artificial saliva, coke mixed with artificial saliva, turmeric mixed with artificial saliva, and coffee mixed with artificial saliva). Beakers containing different dietary media and color modules are kept in the incubator at 37°C for 72 hours. After incubation period, all the segments of module strips removed from the dietary media were placed under the electric lamp and photographs were taken using Canon camera (SX400 IS). Photographs were transferred to GIMP software, and lumen size and thickness variation in the modules was measured.

RESULTS

Statistical analysis were performed using analysis of variance and t-test in Statistical Package for the Social Sciences software. It showed significant difference in thickness of black module in all dietary media. Significant difference existed between all the lumen sizes of four color modules in four dietary media.

CONCLUSION

This study was done to identify the material that has more changes in physical properties when exposed to various dietary media.

CLINICAL SIGNIFICANCE

According to the results obtained, black color modules have increased in lumen size in all dietary media. In thickness, red color module showed less variation and black color module exhibited more variation.

Cost-Sensitive Radial Basis Function Neural Network Classifier for Software Defect Prediction

Effective prediction of software modules, those that are prone to defects, will enable software developers to achieve efficient allocation of resources and to concentrate on quality assurance activities. The process of software development life cycle basically includes design, analysis, implementation, testing, and release phases. Generally, software testing is a critical task in the software development process wherein it is to save time and budget by detecting defects at the earliest and deliver a product without defects to the customers. This testing phase should be carefully operated in an effective manner to release a defect-free (bug-free) software product to the customers. In order to improve the software testing process, fault prediction methods identify the software parts that are more noted to be defect-prone. This paper proposes a prediction approach based on conventional radial basis function neural network (RBFNN) and the novel adaptive dimensional biogeography based optimization (ADBBO) model. The developed ADBBO based RBFNN model is tested with five publicly available datasets from the NASA data program repository. The computed results prove the effectiveness of the proposed ADBBO-RBFNN classifier approach with respect to the considered metrics in comparison with that of the early predictors available in the literature for the same datasets.

Differential bleaching of corals based on El Niño type and intensity in the Andaman Sea, southeast Bay of Bengal

The Andaman coral reef region experienced mass bleaching events during 1998 and 2010. The purpose of this study is to investigate the role of the El Niño in the coral reef bleaching events of the Andaman region. Both Niño 3.4 and 3 indices were examined to find out the relationship between the mass bleaching events and El Niño, and correlated with sea surface temperature (SST) anomalies in the Andaman Sea. The result shows that abnormal warming and mass bleaching events in the Andaman Sea were seen only during strong El Niño years of 1997-1998 and 2009-2010. The Andaman Sea SST was more elevated and associated with El Niño Modoki (central Pacific El Niño) than conventional El Niño (eastern Pacific El Niño) occurrences. It is suggested that the development of hot spot patterns around the Andaman Islands during May 1998 and April-May 2010 may be attributed to zonal shifts in the Walker circulation driven by El Niño during the corresponding period.

Learning style-based teaching harvests a superior comprehension of respiratory physiology

Students entering medical college generally show vast diversity in their school education. It becomes the responsibility of teachers to motivate students and meet the needs of all diversities. One such measure is teaching students in their own preferred learning style. The present study was aimed to incorporate a learning style-based teaching-learning program for medical students and to reveal its significance and utility. Learning styles of students were assessed online using the visual-auditory-kinesthetic (VAK) learning style self-assessment questionnaire. When respiratory physiology was taught, students were divided into three groups, namely, visual (n = 34), auditory (n = 44), and kinesthetic (n = 28), based on their learning style. A fourth group (the traditional group; n = 40) was formed by choosing students randomly from the above three groups. Visual, auditory, and kinesthetic groups were taught following the appropriate teaching-learning strategies. The traditional group was taught via the routine didactic lecture method. The effectiveness of this intervention was evaluated by a pretest and two posttests, posttest 1 immediately after the intervention and posttest 2 after a month. In posttest 1, one-way ANOVA showed a significant statistical difference (P=0.005). Post hoc analysis showed significance between the kinesthetic group and traditional group (P=0.002). One-way ANOVA showed a significant difference in posttest 2 scores (P < 0.0001). Post hoc analysis showed significance between the three learning style-based groups compared with the traditional group [visual vs. traditional groups (p=0.002), auditory vs. traditional groups (p=0.03), and Kinesthetic vs. traditional groups (p=0.001)]. This study emphasizes that teaching methods tailored to students' style of learning definitely improve their understanding, performance, and retrieval of the subject.

Simulation of radioactive plume gamma dose over a complex terrain using Lagrangian particle dispersion model

FLEXPART-WRF is a versatile model for the simulation of plume dispersion over a complex terrain in a mesoscale region. This study deals with its application to the dispersion of a hypothetical air borne gaseous radioactivity over a topographically complex nuclear site in southeastern France. A computational method for calculating plume gamma dose to the ground level receptor is introduced in FLEXPART using the point kernel method. Comparison with another similar dose computing code SPEEDI is carried out. In SPEEDI the dose is calculated for specific grid sizes, the lowest available being 250 m, whereas in FLEXPART it is grid independent. Spatial distribution of dose by both the models is analyzed. Due to the ability of FLEXPART to utilize the spatio-temporal variability of meteorological variables as input, particularly the height of the PBL, the simulated dose values were higher than SPEEDI estimates. The FLEXPART-WRF in combination with point kernel dose module gives a more realistic picture of plume gamma dose distribution in a complex terrain, a situation likely under accidental release of radioactivity in a mesoscale range.

Sentinel node detection in endometrial cancer using indocyanine green and fluorescence imaging-a case report

Sentinel lymph node mapping in endometrial cancer can help to provide the prognostic information needed while avoiding the morbidity associated with a complete lymphadenectomy. Studies with blue dye and technetium colloid have only given about 80% detection rates whereas with indocyanine green injection and fluorescence imaging, it gives about 88–100% detection rates. Herein, we report a case where indocyanine green was injected intracervically and sentinel nodes were detected at the paraaortic nodal area.

‘Green’ biocompatible organic–inorganic hybrid electrospun nanofibers for potential biomedical applications

Gold nanoparticles were prepared by green route using Couroupita guianensis leaves extract. The green synthesized gold nanoparticles exhibited maximum absorbance at 526 nm in the ultraviolet spectrum. By incorporating the green synthesized gold nanoparticles in poly(vinyl alcohol) matrix, unique green organic–inorganic hybrid nanofibers (poly (vinyl alcohol)–gold nanoparticles) were developed by electrospinning. Contact angle measurements showed that the prepared poly (vinyl alcohol)–gold nanoparticles were found to be highly hydrophilic. The crystallinity of gold nanoparticles was analyzed using XRD. The synthesized gold nanoparticles and poly (vinyl alcohol)–gold nanoparticles were characterized using high-resolution transmission electron microscope, Fourier transform-infrared spectroscopy and energy-dispersive analysis of X-ray. The ultimate aim of the present work is to achieve optimum antibacterial, antifungal, biocompatibility and antiproliferative activities at a very low loading of gold nanoparticles. Vero cell lines showed a maximum of 90% cell viability on incubation with the prepared poly (vinyl alcohol)–gold nanoparticles. MCF 7 and HeLa cell lines proliferated only to 8% and 9%, respectively, on incubation with the poly (vinyl alcohol)–gold nanoparticles, and also exhibited good antibacterial and antifungal activities against test pathogenic bacterial and fungal strains. Thus, the poly (vinyl alcohol)–gold nanoparticles could be used for dual applications such as antimicrobial, anticancer treatment besides being highly biocompatible.

Assessment of genotoxic and molecular mechanisms of cancer risk in smoking and smokeless tobacco users

Inexpensive forms of tobacco are widely used in developing countries such as India. We have evaluated genotoxicity endpoints (chromosome aberrations, micronucleus frequency, comet assay) and polymorphisms of the XRCC1 and p53 genes among smokers and smokeless tobacco (SLT) users in rural Tamilnadu, South India. Cytogenetic, DNA damage and SNP analyses were performed on peripheral blood samples; micronucleus frequency was measured in peripheral blood and buccal mucosa exfoliated cells. Both categories of tobacco users had elevated levels of genotoxic damage. SNP analysis of tobacco users revealed that 17% carry the XRCC1 gln399gln genotype and 19% carry the p53 pro72pro genotype. Both genotypes are associated with increased risk of cancer.

Evolution of surgery in advanced epithelial ovarian cancer in a dedicated gynaecologic oncology unit-seven year audit from a tertiary care centre in a developing country

AIMS

To audit our performance as a dedicated gynaecologic oncology unit and to analyse how it has evolved over the years.To retrospectively evaluate the outcome of advanced ovarian cancer treated with neoadjuvant chemotherapy (NACT) followed by interval surgery versus upfront surgery.

METHODS AND RESULTS

One hundred and ninety-eight patients with advanced epithelial ovarian cancer (EOC) who were treated from 2004 to 2010 were analysed. Eighty-two patients (41.4%) underwent primary surgery and 116 (58.6%) received NACT. Overall, an optimal debulking rate of 81% was achieved with 70% for primary surgery and 88% following NACT. The optimal cytoreduction rate has improved from 55% in 2004 to 97% in 2010. In primary surgery, the optimal debulking rate increased from 42.8% in 2004 to 93% in 2010, whereas in NACT group the optimal cytoreduction rate increased from 60% to 100% by 2010. On the basis of the surgical complexity scoring system it was found that surgeries with intermediate complexity score had progressively increased over the years. There was a mean follow-up of 21 months ranging from 6 to 70 months. The progression-free survival and overall survival (OS) in patients undergoing primary surgery were 23 and 40 months, respectively, while it was 22 and 40 months in patients who received NACT. However, patients who had suboptimal debulking, irrespective of primary treatment, had significantly worse OS (26 versus 47 months) compared with those who had optimal debulking.

CONCLUSIONS

As a dedicated gynaecologic oncology unit there has been an increase in the optimal cytoreduction rates. The number of complex surgeries, as denoted by the category of intermediate complexity score, has increased. Patients with advanced EOC treated with NACT followed by interval debulking have comparable survival to the patients undergoing primary surgery. Optimal cytoreduction irrespective of primary modality of treatment gives better survival.

Role of community pharmacists in improving knowledge and glycemic control of type 2 diabetes

Objective:

To study the role of the community pharmacists in improving knowledge and glycemic control in patients with type 2 diabetes residing in villages of Coimbatore district, Tamil Nadu.

Materials and Methods:

Fifty patients were interviewed, of whom 39 subjects were included in the study. The literate and chronic diabetic patients were included in the study and illiterate, children below 12 years of age, pregnant women, nursing mothers and subjects with any other chronic disorders were excluded from the study. The subjects were interviewed and divided randomly into two groups. There were 20 subjects in the control group and 19 in the intervention group. The study protocol was explained to all the participants, and written informed consent was obtained from them. Before the initiation of the study, the subjects were interviewedfor 20–40 min to educate them about diabetes. Subjects in the intervention group received continuous counselling and medical advice to improve their awareness about the disease and drugs. During the study period, the Diabetes Care Profile (a questionnaire developed by J.J. Fitzgerald of the Michigan Diabetes Research and Training Center, University of Michigan Medical School, Michigan) was performed to each subject. The interval between visits was 2 months. All the values are expressed in mean ± standard deviation.

Results:

The intervention group showed better progress in the recovery of diabetics because of the continuous counselling and monitoring. There were significant changes in Diabetes Care Profile subscale scores in both the control and the intervention groups at the end of the study, viz. 1.8 ± 4.52 to 2.75 ± 6.62 and 3.10 ± 3.23 to 1.53 ± 2.66. Similarly, the knowledge test score was found to be increased in the intervention group compared with the baseline values (8.53 ± 1.81 to 12.16 ± 1.34).

Conclusions:

At the end of the study period, the patients of the intervention group had very good glycemic control. Their health status and understanding of diabetes and its management were better, and they had fewer problems such as episodes of hyperglycemia or hypoglycemia.

Genotoxicity assessment in smokeless tobacco users: a case-control study

India has a long history of tobacco, which includes chewing tobacco and smoking tobacco in various forms. Initially, the smokeless tobacco chewing habit was seen among the majority of the farmers who cultivated tobacco; but in recent years, smokeless tobacco is available in many forms and is cheaper as well and hence it is widely being used among literate and illiterate people. The subjects of our study are living in hilly regions of Yerkaud in Salem district, South India. Most of the inhabitants of our study area are illiterate and more particularly they are unaware of the health effects due to tobacco use. Recent epidemiological reports have strongly indicated the association of cancer risk with usage of smokeless tobacco. The prime aim of our study is to evaluate the genotoxic effects of tobacco use by analysing the cytogenetic end points such as chromosome aberrations in peripheral blood and micronucleus in peripheral blood and buccal cells. About 85 smokeless tobacco users were enrolled for the study and same numbers of age- and sex-matched nontobacco users were also enrolled to serve as controls. The result of our study revealed that tobacco users displayed varied levels of elevated chromosomal damage and micronucleated cells than nontobacco users. The variation in the extent of genetic damage was dependent on the duration of the tobacco use. In conclusion, this study might be helpful in creating awareness on the hazards of the smokeless tobacco products among the global population as a whole for those who chose such products as a cheap alternative to tobacco smoke.

XRCC1 gene variants and possible links with chromosome aberrations and micronucleus in active and passive smokers

Tobacco addiction is a major risk for diseases such as cancers, heart attack, etc. Tobacco smoke constitutes environmental toxins that are the major preventable leading cause of death worldwide. We investigated the influence of tobacco smoke on cytogenetic parameters (chromosomal aberrations and micronuclei) and the influence of XRCC1 arg399gln polymorphism on the cytogenetic parameters of the exposed subjects. The cases for this study include active and passive smokers. They were divided into three groups in accordance with duration of exposure to tobacco smoke. We observed changes in the frequency of chromosomal aberrations and micronuclei among the exposed subjects and controls. Of the three groups of exposed subjects, group III of active smokers and group III of passive smokers showed higher number of chromosomal aberrations and micronuclei when compared to controls, group I and group II of active and passive smokers. The XRCC1 arg399gln polymorphic variant gln/gln, influenced the extent of genotoxic damage in chromosomes and frequency of in micronuclei the three variants (arg/arg, arg/gln and gln/gln), gln/gln harbored significantly (P<0.05) higher number of aberrations than the arg/arg and arg/gln. In this context, the results observed in our study indicated that the single nucleotide polymorphism on XRCC1codon 399 influenced the frequencies of chromosomal aberrations and micronuclei.

Development and applications of energy-specific fluence monitor for field monitoring

A portable energy-specific fluence monitor is developed for field monitoring as well as to serve as stand-alone data acquisition system to measure dose rate due to routine releases at various locations in and around Nuclear Power Reactors. The data from an array of such monitors deployed over a region of interest would help in evolving a methodology to arrive at the source term evaluation in the event of a postulated nuclear incident. The other method that exists for this purpose is by conducting tracer experiments using known release of a gas like SF(6) into the atmosphere and monitoring their concentrations downwind. The above instrument enables one to use the routine release of (41)Ar as a tracer gas. The Argon fluence monitor houses a CsI(Tl) detector and associated miniature electronics modules for conditioning the signal from the detector. Data logging and in-situ archival of the data are controlled by a powerful web enabled communication controller preloaded with Microsoft Windows Compact Edition (WIN CE). The application software is developed in Visual Basic.NET under Compact Framework and deployed in the module. The paper gives an outline of the design aspects of the instrument, associated electronics and calibration of the instrument, including the preliminary results obtained using the instrument. The utility of the system is established by carrying out field survey around Madras Atomic Power Station (MAPS), consisting of two Pressurized Heavy Water Reactors (PHWR), by mapping the (41)Ar plume. Additional features such as enhancing the monitor capability with embedded GPS along with real-time linking using wireless networking techniques are also being incorporated.

Variations of physicochemical properties in Kalpakkam coastal waters, east coast of India, during southwest to northeast monsoon transition period

A significant variation in physicochemical properties of the Kalpakkam coastal waters, eastern part of India, was observed during the event of southwest to northeast monsoon transition. Increase in nitrate, total nitrogen, and silicate concentrations were noticed during post-transition period. Ammonia concentration was at peak during transition period as compared to pre- and post-transition periods. Hypo-saline condition (~23 psu) was observed during post-transition as the surface water salinity decreased by ~10 psu from the pre-transitional values. Turbidity, suspended particulate matter, phosphate and total phosphorous values decreased marginally, coinciding with northward to southward current reversal. A drastic decrease (eightfold) in chlorophyll-a concentration was observed in the coastal water during post-transition period.

16S rDNA sequence analysis of culturable marine biofilm forming bacteria from a ship's hull

Marine bacteria from the hull of a ship in the form of biofilms or microfouling were isolated, cultured, and identified by phylogenetic analysis using 16S rDNA sequences. With an average length of 946 bp, all the 16 sequences were classified using the Ribosomal database project (RDP) and were submitted to the National Center for Biotechnology Information. Phylogenetic analysis using 16S rDNA sequences indicated that the 16 strains belonged to the Firmicutes (IK-MB6 Exiguobacterium aurantiacum, IK-MB7 Exiguobacterium arabatum, IK-MB8 Exiguobacterium arabatum, IK-MB9 Jeotgalibacillus alimentarius, IK-MB10 Bacillus megaterium, IK-MB11 Bacillus pumilus, IK-MB12 Bacillus pumilus, IK-MB13 Bacillus pumilus, IK-MB14 Bacillus megaterium), High GC, Gram-positive bacteria (IK-MB2 Micrococcus luteus, IK-MB5 Micrococcus luteus, IK-MB16 Arthrobacter mysorens), G-Proteobacteria (IK-MB3 Halomonas aquamarina, IK-MB15 Halotalea alkalilenta), CFB group bacteria (IK-MB1 Myroides odoratimimus), and Enterobacteria (IK-MB4 Proteus mirabilis). Among the 16 strains, representatives of the Firmicutes were dominant (56.25%) compared to the high GC, Gram-positive bacteria (18.75%), G-Proteobacteria (12.5%), CFB group bacteria (6.25%), and Enterobacteria (6.25%). Analysis revealed that majority of marine species found in marine biofilm are of anthropogenic origin.

Barnacle cement: an etchant for stainless steel 316L?

Localized corrosion of stainless steel beneath the barnacle-base is an unsolved issue for the marine industry. In this work, we clearly bring out for the first time the role of the barnacle cement in acting as an etchant, preferentially etching the grain boundaries, and initiating the corrosion process in stainless steel 316L. The investigations include structural characterization of the cement and corroded region, and also chemical characterization of the corrosion products generated beneath the barnacle-base. Structural characterization studies using scanning electron microscopy (SEM) reveals the morphological changes in the cement structure across the interface of the base-plate and the substrate, modification of the steel surface by the cement and the corrosion pattern beneath the barnacle-base. Fourier transform infrared spectroscopy (FTIR) of the corrosion products show that they are composed of mainly oxides of iron thereby implying that the corrosion is aerobic in nature. A model for the etching and corrosion mechanism is proposed based on our observations.

Barnacle cement: An etchant for stainless steel 316L?

Localized corrosion of stainless steel beneath the barnacle-base is an unsolved issue for the marine industry. In this work, we clearly bring out for the first time the role of the barnacle cement in acting as an etchant, preferentially etching the grain boundaries, and initiating the corrosion process in stainless steel 316L. The investigations include structural characterization of the cement and corroded region, and also chemical characterization of the corrosion products generated beneath the barnacle-base. Structural characterization studies using scanning electron microscopy (SEM) reveals the morphological changes in the cement structure across the interface of the base-plate and the substrate, modification of the steel surface by the cement and the corrosion pattern beneath the barnacle-base. Fourier transform infrared spectroscopy (FTIR) of the corrosion products show that they are composed of mainly oxides of iron thereby implying that the corrosion is aerobic in nature. A model for the etching and corrosion mechanism is proposed based on our observations.