Study of mixing ratios of SO2 in a tropical rural environment in south India

Sulphur dioxide is a toxic pollutant in the atmosphere emitted from natural sources and human activities. Normally, SO2 has a life-time of about 2 days in the atmosphere and is not transported to long distances from its source region. However, under favourable circumstances such as low humidity or high wind speed, it can travel intercontinental distances from the point of emission. In this article, we have analysed the surface mixing-ratio of SO2 measured over the time period from January 2010 to April 2012 at a rural region in south India. It is found that SO2 mixing-ratio is very low over this region with an annual mean value in the range of 0.21–0.24 ppbv. OMI satellite estimates an annual mean value of 0.5 Dobson Units (DU) over the same location and period. However, during January to May relatively higher concentrations of SO2 are observed, mainly coming from power plants located in southern and eastern India as indicated by higher SO2/NO2 ratios of greater than 0.5. In one instance, on June 20th, 2011, it is found that the OMI SO2 value was a factor of 13 higher than 2011 annual mean at Gadanki. Using the FLEXible PARTicle dispersion model (FLEXPART) and satellite data, it is found that the observed higher SO2 value on 20th June was due to intercontinental transport of SO2 from Nabro volcanic eruption. Using the FLEXPART model with ECLIPSE-v5 emission inventory, the observed seasonal variation of SO2 could be well reproduced; however, the mixing ratios are found to be overestimated. CAMS (Copernicus Atmosphere Monitoring Service) SO2 reanalysis values available through its implementation in the ECMWF Integrated Forecasting System are a factor of 7.8 higher than observations, possibly due to incorrect vertical profile used in the model

IR-HF-WED: IMAGE RETRIEVAL USING HYBRID FEATURE EXTRACTION WITH WEIGHTED EUCLIDEAN DISTANCE

Attributable to the fast development of image acquisition and storage modernization, image retrieval plays a key role in different applications such as Medical Imaging, Visual Data Mining etc. Due to high storage complexity Image Retrieval needs complex algorithms to retrieve images in efficient and fast manner. Image Retrieval technique using Hybrid Feature Extraction with Weighted Euclidean Distance (IR-HF-WED) is proposed to reduce the time complexity and increase the accuracy. Multiple features are extracted using Color Co-occurrence Matrix (CCM), Histogram of oriented Gradient (HoG), Compound Local Binary Pattern (CLBP) and Difference Between Pixels of Scanned Patterns (DBPSP). The proposed algorithm is tested and analyzed by comparing with Absolute Distance (AD), Euclidean Distance (ED), Cross Correlation (X) distance matching techniques and it is found that IR-HF-WED outperforms with respect to Precision and Recall compared to the [1, 2]

CBH-MAC: Contention-Based Hybrid MAC Protocol for WSNs

It is challenging to design a hybrid MAC scheme for delay aware data traffic in WSNs. The Contention-Based Hybrid MAC (CBH-MAC) protocol is proposed where each sensor node operates the reservation procedure used in cross and chain topology, resulting in energy efficiency, maximizing the packet delivery ratio, minimizing contention around the nodes, and reducing end-to-end delay. The neighboring sensor nodes of the receiver and sender receive their individual reservation control packets. The sender transmits data and receives acknowledgment packets during the adaptive contention-free period. As the reservation packets pass through the sensor along the routing path, the sensor nodes reserve the time slots consecutively in multi-hop. The scheme has significant improvement in the end-to-end latency, packet delivery ratio, and energy efficiency

Joint Channel and Interference Aware Cooperative Routing for Cognitive Radio Network

Cognitive Radio based network technology provides a promising solution for various types of real-time wireless communication by offering better spectrum utilization and resource allocation. Generally, the dynamic network topology, interference, channel switching and under-utilization of resource can degrade the network performance. Therefore, development of promising solution to obtain the desired performance is a challenging research topic in CRNs. Several researches have been carried out which have focused on development of routing protocol for CRNs to improve the performance. These routing protocols are classified as local and global routing which are mainly focused on overhead reduction and optimal route selection respectively. However, the conventional approaches suffer from various issues such as interflow-interference, channel switching delay and node overhearing problems which can progress towards the poor network performance. In this paper, our objective is to focus on the inter-flow interference, channel switching delay, and develop a cooperative communication based approaches where inter-flow interference and overhearing issues are mitigated using cooperative communication. Furthermore, Switching Delay and Interference (SDI) routing metric is developed to reduce the switching delay and also finally, a cooperative scheme of packet transmission is developed where direct or cooperative communication is selected for successful packet transmission. The proposed approach jointly considers channel and interference issue, hence it is known as Joint Cooperative Channel and Interference Aware Routing (JCIAR). The performance of proposed approach is compared with the existing techniques such as Primary User Aware k-hop route discovery scheme (PAK), AODV, CognitiveAODV, and Location-Aided Routing for CRN (LAUNCH) in terms of delay, packet delivery rate and throughput. The obtained result shows a significant improvement in network performance

Correction To: Impact of Transient Temperature Disturbance on the Oxidative Stress Indices and Glucose Levels of Juvenile Koi Carps (Cyprinus carpio Var koi)

An amendment to this paper has been published and can be accessed via the original article

Impact of Transient Temperature Disturbance on the Oxidative Stress Indices and Glucose Levels of Juvenile Koi Carps (Cyprinus carpio Var koi)

Background The present study reports the changes in the redox state and glucose activity in gills and muscles of Koi carps, exposed to a short duration of acute thermal stress. The variation in levels of lipid peroxidation (LPO) and glutathione (GSH), catalase (CAT) and glutathione-S-transferase (GST) activity, in addition to glucose levels, were analysed after exposing the fishes to 15 °C (low), 25 °C (control) and 35 °C (high) for a duration of 3 and 6 h. The upper and lower temperatures regimes were decided by the Critical Thermal Limit (CTMAX and CTMIN). Results The CAT activity was high in both the tissues at 35 °C within 3 h, while LPO activity decreased throughout the study when compared with the control group indicating immoderate cellular disturbance and surplus oxidative stress. At 15 °C (3 h), tissues reported more glucose compared with the upper thermal slab. GSH increased in both the tissues at 15 °C compared with the control for 3 and 6 h. GST activity, however, flourished at 35 °C in muscles and gills for the 3-h regime. Conclusion The current study demonstrated disturbing impacts of temperature on the survivability of the Koi carps in a domesticated environment

Trap Stiffness Modification of an Optically Trapped Microsphere through Directed Motion of Nanoparticles

We report an enhancement in the corner frequency of an optically trapped non-magnetic microsphere in the plane perpendicular to the laser propagation direction on addition of ferrofluid to the suspension medium. We conjecture that a directed motion of the nanoparticles toward the trap in this plane is responsible for the augmentation. Changes in the corner frequency in the presence of external magnetic field gradients lend credence to this conjecture. Corner frequency augmentation is also observed when zinc oxide nanoparticles are used. Here, however, no further changes are seen in the presence of magnetic field gradients

EPC: Efficient Gateway Selection for Passive Clustering in MWSNs

Passive clustering does not employ control packets to collect topological information in a Mobile Wireless Sensor Networks (MWSNs). The primary objective is to make Passive Clustering more practical, robust, and to minimize the quantity of cluster information on the data packets. In this chapter, we propose an intelligent gateway selection heuristic along with a time-out mechanism and an efficient passive clustering algorithm that employs an optimal number of gateways to reduce the number of rebroadcast and improve the QoS of the network. In this proposal, we avoid making frequent changes in cluster architecture, caused due to repeated election and re-election of cluster heads and gateways