Extraction of lignocellulosic fiber and cellulose microfibrils from agro waste-palmyra fruit peduncle: Water retting, chlorine-free chemical treatments, physio-chemical, morphological, and thermal characterization.

In this paper, lignocellulosic fibers and cellulose microfibrils (CMFs) were extracted from palmyra fruit peduncle waste and investigated as naturally derived cellulosic materials for their potential use as reinforcement materials in composite applications. The physicochemical, mechanical, and thermal properties of the extracted fiber were studied. Physical and morphological analysis results revealed an extracted fiber diameter of 82.5 µm with a very rough surface, providing excellent interfacial bonding performance with the polymer matrix. Chemical, mechanical, and thermal results showed that the fibers consist mainly of cellulose as their crystallized phase, with a cellulose content of 56.5 wt% and a tensile strength of 693.3 MPa, along with thermal stability up to 252 °C. The chemically extracted CMFs exhibit a short, rough-surfaced, cylindrical cellulose structure with a diameter range of 10-15 µm. These CMFs demonstrate excellent thermal stability, withstanding temperatures up to 330 °C. Furthermore, the formation of CMFs is evident from a substantial increase in the crystallinity index, which increased from 58.2 % in the raw fibers to 78.2 % in the CMFs. FT-IR analysis further confirms the successful removal of non-cellulosic materials through chlorine-free chemical treatments. These findings strongly support the potential use of extracted fibers and CMFs as reinforcement materials in polymers.

Impact of a large hydraulic barrage on the trace metals concentration in mesozooplankton in the Kochi backwaters, along the Southwest coast of India.

This study delineates the impact of a man-made hydrological barrage [Thannermukkom barrage (TB)] on the concentration of selected trace metals (Fe, Zn, Cu, Co, Cr, Mn, Ni, Pb) in mesozooplankton from the Kochi backwaters (KBW). The overall results point out that during Pre-Southwest Monsoon (PRM), the concentration of trace metals in mesozooplankton was high in the upstream due to the closure of the barrage, which essentially causes stagnancy of the waters. Trace metal concentrations in the downstream and upstream regions of KBW were found to be lower during Post- Southwest Monsoon (PSWM) compared to the rest of the seasons. In general, trace metals in mesozooplankton from the KBW showed the following order of concentration: Fe > Mn > Zn > Ni > Cu > Cr > Co > Pb. A comparison with earlier data across the globe showed that trace metal concentration in mesoplankton in the KBW is lower than the values reported from other parts of the world.

Mud Banks along the southwest coast of India are not too muddy for plankton.

Considering Alappuzha Mud Bank in the southern Kerala coast as a typical case of biologically productive Mud Banks that form along the southwest coast of India during the Southwest Monsoon (June - September), the present study addresses several pertinent missing links between the physical environment in Mud Banks and their influence on plankton stock. This study showed that very strong coastal upwelling prevails in the entire study domain during the Southwest Monsoon, which manifests itself in the form of significantly cool, hypoxic and nitrate-rich waters surfacing near the coast. The upwelled water persisting throughout the Southwest Monsoon period was found to have fuelled the exceptionally high phytoplankton stock in the entire study area, including the Mud Bank region. Having accepted that Mud Banks are special because of the calm sea surface conditions and relatively high turbidity level in the water column around them, the present study showed that except at points close to the sea bottom, turbidity level in the Alappuzha Mud Bank was below the critical level to inhibit the plankton stock. The suspended sediments that form in the Mud Bank occasionally could be attributed to the disturbance of the bottom fluid muddy layer and their vertical spurts.

Feeding preference and daily ration of 12 dominant copepods on mono and mixed diets of phytoplankton, rotifers, and detritus in a tropical coastal water.

Results of the experimental studies on the feeding habit and daily ration (DR) of 12 dominant copepods from a tropical coastal water (off Kochi, Southwest coast of India) on different food items (phytoplankton, rotifers, and detritus) are presented. Even though, all species of copepods consumed all types of food items in the experiments, they showed noticeable feeding preferences, having important ecological implications. Calanoid Paracalanus parvus and Acrocalanus gracilis consumed phytoplankton and rotifers equally in mono diets (74-89% of DR) and mixed diets (53-82% of DR), which indicated their ability to shift their diet in natural environment based on the availability of food items. Calanoid Acartia erythraea and A. danae consumed more phytoplankton (DR 83 and 72%, respectively) than rotifers (DR 51 and 46%, respectively) in mono diets, and in mixed diets, their consumption was high in phytoplankton combined food mixtures (P + R DR and P + D DR) rather than the R + D food type, indicated their preference for mixed diets of phytoplankton. Similarly, Calanoid Temora turbinata, Pseudodiaptomus serricaudatus, and Centropages tenuiremis preferred a herbivorous diet as evidenced by their high ingestion rate on phytoplankton mono (70 to 87% to their DR) and mixed diets (58 to 80% of DR). On the other hand, Cyclopoid Oithona similis and Poecilostomatoid Corycaeus danae preferred a carnivorous diet, consuming more rotifers (> 80% of DR) than phytoplankton (18-20% of DR) and detritus (5-6% of DR). Harpacticoids Macrosetella gracilis and Euterpina acutifrons equally preferred phytoplankton (78-92% of DR) and detritus (65-89% of DR). The study showed that the dominant copepods in the coastal waters off Kochi occupy different trophic niches available in the environment, which may be applicable in other similar environments as well.

Effective fuzzy c-means based kernel function in segmenting medical images.

The objective of this paper is to develop an effective robust fuzzy c-means for a segmentation of breast and brain magnetic resonance images. The widely used conventional fuzzy c-means for medical image segmentations has limitations because of its squared-norm distance measure to measure the similarity between centers and data objects of medical images which are corrupted by heavy noise, outliers, and other imaging artifacts. To overcome the limitations this paper develops a novel objective function based standard objective function of fuzzy c-means that incorporates the robust kernel-induced distance for clustering the corrupted dataset of breast and brain medical images. By minimizing the novel objective function this paper obtains effective equation for optimal cluster centers and equation to achieve optimal membership grades for partitioning the given dataset. In order to solve the problems of clustering performance affected by initial centers of clusters, this paper introduces a specialized center initialization method for executing the proposed algorithm in segmenting medical images. Experiments are performed with synthetic, real breast and brain images to assess the performance of the proposed method. Further the validity of clustering results is obtained using silhouette method and this paper compares the results with the results of other recent reported fuzzy c-means methods. The experimental results show the superiority of the proposed clustering results.