Evaluation of polyhalite on growth, yield attributes and yield of blackgram (Vigna mungo L.)

Potassium is involved in a diverse range of processes within plants that are needed for their growth, yield and better quality. The polyhalite as a hydrated evaporate mineral that can be used directly as a source of potassic fertilizer. However, research on polyhalite's appropriateness and effectiveness, the present investigation aimed to evaluate the effect of polyhalite on growth, yield attributes, and yield of blackgram variety ADT 5 at Chinnakandiankuppam village, Vriddhachalam, Cuddalore district, Tamil Nadu, during 2021. The experiment was laid out in randomized block design consisting of ten treatments viz., T1 (absolute control), T2 (-K), T3 (12.5 kg K2O ha-1 as muriate of potash (MOP)), T4 (25 kg K2O ha-1as MOP), T5 (37.5 kg K2O ha-1 as MOP), T6 (50 kg K2O ha-1 as MOP), T7 (12.5 kg K2O ha-1 as polyhalite),  T8 (25 kg K2O ha-1 as polyhalite), T9 (37.5 kg K2O ha-1 as polyhalite), T10 (50 kg K2O ha-1 as polyhalite). The experiment revealed that the application of 37.5 kg K2O ha-1 as polyhalite (T9) significantly (5%) enhanced the growth attributes (plant height (38.7 cm), number of branches plant-1 (12.97), leaf area index (2.13), number of nodules plant-1 (18.76) and dry matter production (1972 hg ha-1), yield attributes (pod length (8.21 cm), number of pods plant-1 (20.05), number of seeds pod-1 (7.14) and test weight (3.53 g)) and grain yield (1439 kg ha-1), haulm yield (1876 kg ha-1) of blackgram. Thus the study would be helpful to farmers for yield maximization of blackgram through polyhalite as potassic fertilizer.    

Electron Microscopy of Multi-walled Carbon Nanotubesfor Display Devices Application

The opportunity of creating and tailoring unprecedented and beautifully symmetric 3-D structures haspropelled the science of carbon nanotubes to become one of the highly promising areas in the field ofnanotechnology. The unique properties of carbon nanotubes have promoted research in the fabrication ofdevices composed of carbon nanotubes and in other applications. Characterisation tools are crucial in the studyof these emerging materials to evaluate their full potential in applications and to comprehend their basicproperties. The aim of this study was electron microscopy characterisation of the carbon nanotubes synthesisedto fabricate display devices. Both thermal chemical vapour deposition (CVD) and plasma enhanced chemicalvapour deposition routes were used to synthesise patterned and aligned carbon nanotubes. Several batchesof CNTs were produced by varying the process parameters such as growth temperature, gas ratio, durationof growth, catalyst condition, etc. Characterisation of these CNTs have been done using scanning electronmicroscope, transmission electron microscope, high resolution transmission electron microscope, and electronenergy loss spectrum. Structure, uniformity, chemistry, diameter, length, number of walls of the multi-wallednanotubes were characterised using various electron microscopes, which finally lead to the production of thedisplay devices using CNTs.Defence Science Journal, 2008, 58(5), pp.655-663, DOI:http://dx.doi.org/10.14429/dsj.58.168

Signals of selection in the mitogenome provide insights into adaptation mechanisms in heterogeneous habitats in a widely distributed pelagic fish

Oceans are vast, dynamic, and complex ecosystems characterized by fluctuations in environmental parameters like sea surface temperature (SST), salinity, oxygen availability, and productivity. Environmental variability acts as the driver of organismal evolution and speciation as organisms strive to cope with the challenges. We investigated the evolutionary consequences of heterogeneous environmental conditions on the mitogenome of a widely distributed small pelagic fish of Indian ocean, Indian oil sardine, Sardinella longiceps. Sardines were collected from different eco-regions of the Indian Ocean and selection patterns analyzed in coding and non-coding regions. Signals of diversifying selection were observed in key functional regions involved in OXPHOS indicating OXPHOS gene regulation as the critical factor to meet enhanced energetic demands. A characteristic control region with 38–40 bp tandem repeat units under strong selective pressure as evidenced by sequence conservation and low free energy values was also observed. These changes were prevalent in fishes from the South Eastern Arabian Sea (SEAS) followed by the Northern Arabian Sea (NAS) and rare in Bay of Bengal (BoB) populations. Fishes belonging to SEAS exhibited accelerated substitution rate mainly due to the selective pressures to survive in a highly variable oceanic environment characterized by seasonal hypoxia, variable SST, and food availability

Toxic Metals Enrichment in the Surficial Sediments of a Eutrophic Tropical Estuary (Cochin Backwaters, Southwest Coast of India)

Concentrations and distributions of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in surficial sediments of the Cochin backwaters were studied during both monsoon and pre-monsoon periods. Spatial variations were in accordance with textural charaterstics and organic matter content. A principal component analysis distinguished three zones with different metal accumulation capacity: (i) highest levels in north estuary, (ii) moderate levels in central zone, and (iii) lowest levels in southern part. Trace metal enrichments are mainly due to anthropogenic contribution of industrial, domestic, and agricultural effluents, whose effect is enhanced by settling of metals due to organic flocculation and inorganic precipitation associated with salinity changes. Enrichments factors using Fe as a normalizer showed that metal contamination was the product of anthropogenic activities. An assessment of degree of pollution-categorized sediments as moderately polluted with Cu and Pb, moderately-to-heavily polluted with Zn, and heavily-to-extremely polluted with Cd. Concentrations at many sites largely exceed NOAA ERL (e.g., Cu, Cr, and Pb) or ERM (e.g., Cd, Ni, and Zn). This means that adverse effects for benthic organisms are possible or even highly probable

A different approach to soil analysis: Indicative studies

Soil analysis is a tool that has been employed with the primary goal of providing recommendations for soil rectification, crop productivity and for soil health management. Time tested methods like ammonium acetate extraction and diethylene triamine penta acetic acid (DTPA) are commonly used for analysis of bioavailable nutrients. However, there are some limitations to these methods as both extraction fluids are buffered to neutral or near-neutral pH. Hence extracted nutrients represent a “potential or ideal-case” fertility status of soil instead of an “actual” field status. In the ‘Regular methods’, we are overlooking the role of pH, the master variable, in determining the availability of nutrients. Hence, in ‘Modified methods’, the extraction fluid is buffered to actual soil pH. Results obtained with over 150 random samples representing a range of pH, have indicated a difference in values between regular and modified extraction methods. The modified methods (MM) of ammonium acetate and DTPA extraction adjusted to soil pH were found to be better than regular method (RM) for estimation of calcium, magnesium with ammonium acetate and iron and manganese with DTPA in alkaline soils above pH 8.0. For a complete picture of soil health, productivity and fertility, microbiological and enzymatic analysis of soils were included in the present study. Soil solution equivalent medium (SSE) was found to be the appropriate culture medium for microbial counts. A linear relationship was found between urease activity and available nitrogen of soil

Experimental and numerical study of stenotic flows

Atherosclerosis has been leading cause of deaths in several countries. Recent technical advances have allowed the investigation of stenotic flows and in understanding the implications with increased severity. Such studies shall provide detailed understanding of flow across stenosis and its progression. In the present study, a large artery representing segment of aorta is considered as test specimen. Experimental study is carried out by generating the pulsatile flow through pulsatile duplicator. Flow across normal and various severities of stenosis such as 25%, 50% and 75% are studied. Numerical simulation using CFD is also carried out in similar normal and stenosed models. A novel concept of using pulse duplicator to generate pulsatile waves and investigate the different stenosed models has been adopted. Results obtained experimentally and numerically are compared and agree well with that of clinical observations. This study demonstrates significant variation of haemodynamic in post-stenotic region with increased stenosis. Increased pulse pressure, phase lag is observed with increased severity. It is also observed that stenosis greater than 75% is significant as flow complexity is induced with considerable disturbance even in early and latter part of pulse cycle. Such study shall be useful in understanding the flow changes in stenosis and enhance clinical observation

Microstructural and Compositional Characterisation of Electronic Materials

Microstructural and compositional characterisation of electronic materials in support of the development of GaAs, GaN and GaSb based multilayer device structures is described. Electron microscopy techniques employing nanometer and sub-nanometer scale imaging capability of structure and chemistry have been widely used to characterise various aspects of electronic and optoelectronic device structures such as InGaAs quantum dots, InGaAs pseudomorphic (pHEMT) and metamorphic (mHEMT) layers and the ohmic metallisation of GaAs and GaN high electron mobility transistors, nichrome thin film resistors, GaN heteroepitaxy on sapphire and silicon substrates, as well as InAs and GaN nanowires. They also established convergent beam electron diffraction techniques for determination of lattice distortions in III-V compound semiconductors, EBSD for crystalline misorientation studies of GaN epilayers and high-angle annular dark field techniques coupled with digital image analysis for the mapping of composition and strain in the nanometric layered structures. Also, in-situ SEM experiments were performed on ohmic metallisation of pHEMT device structures. The established electron microscopy expertise for electronic materials with demonstrated examples is presented

Mudbanks and fisheries along the Kerala coast – myth and reality

Mudbanks, a unique coastal oceanographic phenomenon occurring along the southwest (SW) coast of India during the SW monsoon season, are synonymous with the fishery of this region. Here we examine the validity of the popular notion that mudbanks directly support rich fisheries, using a high temporal resolution water column data collected from the Alappuzha mudbank region in Kerala during April to September 2014, in conjunction with fisheries data. Our study reveals that the upwelling which occurs during the SW monsoon season along this coast brings oxygendeficient subsurface water to the upper water column. Escaping the oxygen-depleted waters, the fish aggregate within a thin upper layer allowing easy visual identification and capture of fish shoals. This process occurs throughout the coast and is not confined just to the mudbanks. Mudbank being a calm region, traditional fishermen using non-motorized country craft were able to carry out fishing within this region only during the SW monsoon. With the induction of motorized and mechanized fishing, the link between mudbanks and fisheries is becoming less prominent, although the former still continue to be important fish landing centres

Good Environment Management of cage farming using a coupled 3D hydrodynamic particle tracking model - A case study from Pizhala, Cochin, India

Hydrographic conditions such as water level, velocity, adequate water circulation and stratifications have a strong influence on the management of fish cage culture in the estuarine environment. In this study, a 3D hydrodynamic model was used to identify the areas of the mixed and stratified water column and to use this in conjunction with particle tracking models for appropriate site selection for cage culture. A Lagrangian method was used to simulate the instantaneous release of "particles" emulating discharge from fish cages to show the behaviour of waste in terms of water circulation and water exchange. Model simulation at Pizhala cage farm revealed that desirable water exchange is experienced in the monsoon and pre-monsoon period. There have existed strong spring-neap variability in the water level with an average range of 0.7 m with a speed of < 0.12 m/s in pre-monsoon and < 0.24 m/s in monsoon. This consistent flow patterns in the Pizhala region helps in the replenishment of oxygenated water and removal of waste produced beneath the cages, and it is corroborated by the Lagrangian particle transport model experiment coupled with Finite Volume Community Ocean Model (FVCOM) in the study