Continuous Fixed-Bed Column Studies on Congo Red Dye Adsorption-Desorption Using Free and Immobilized Nelumbo nucifera Leaf Adsorbent.

The adsorption of Congo red (CR), an azo dye, from aqueous solution using free and immobilized agricultural waste biomass of Nelumbo nucifera (lotus) has been studied separately in a continuous fixed-bed column operation. The N. nucifera leaf powder adsorbent was immobilized in various polymeric matrices and the maximum decolorization efficiency (83.64%) of CR occurred using the polymeric matrix sodium silicate. The maximum efficacy (72.87%) of CR dye desorption was obtained using the solvent methanol. Reusability studies of free and immobilized adsorbents for the decolorization of CR dye were carried out separately in three runs in continuous mode. The % color removal and equilibrium dye uptake of the regenerated free and immobilized adsorbents decreased significantly after the first cycle. The decolorization efficiencies of CR dye adsorption were 53.66% and 43.33%; equilibrium dye uptakes were 1.179 mg g-1 and 0.783 mg g-1 in the third run of operation with free and immobilized adsorbent, respectively. The column experimental data fit very well to the Thomas and Yoon-Nelson models for the free and immobilized adsorbent with coefficients of correlation R2 ≥ 0.976 in various runs. The study concludes that free and immobilized N. nucifera can be efficiently used for the removal of CR from synthetic and industrial wastewater in a continuous flow mode. It makes a substantial contribution to the development of new biomass materials for monitoring and remediation of toxic dye-contaminated water resources

Connected majority domination vertex critical graphs

In this article, how the removal of a single vertex from a graph G can change the Connected Majority Domination number is surveyed for any graph G. A graph is Connected Domination Critical if the removal of any vertex decreases or increases its Connected Majority Domination Number. This paper gives examples and properties of CMD vertex critical graphs. There are two types namely CVR and UVR with respect to CMD sets of a graph. Also the vertex classification. V⁰CM(G), V ⁻CM(G) and V⁺CM are studied, characterisation theorems of these vertex classification are determined

Bit error rate test for optical communication link using prbs generated by an fpga - system design

Bit Error Rate Testing(BERT) was implemented using Cyclone III FPGA Starter Kit along with THDB_ADA board and interfaced with several kilometers long optical fiber, to study the link performance of the optical communication system. In this, a single FPGA acts as both transmitter and receiver. The logic to transmit the PRBS bits using LFSR and receive them at the receiver to check for bit errors was implemented

Philosophy analysis of AISI 316/AISI 410 stainless steel joint by means of mechanical and metallurgical properties using TIG welding method

This study employed Taguchi's Grey Relational Analysis (GRA) to assess the optimization of process boundaries. Improved metallurgical and mechanical qualities of Martensite (AISI 410) and Austenitic (AISI 316) stainless steel joints were the aim of the investigation. In order to do this, TIG welding experiments were carried out with different current flows, welding speeds, and shielding gas flow rates. Responses like tensile strength and microhardness were taken into consideration to determine the ideal procedure settings. Analysis of variance had been used to determine their impacts.  The best set of parameters was found to be 10 lit/min shielding gas flow, 2 m/min welding speed, and 120-amp welding current based on the GRA. The distribution of alloys, the microhardness of different weld zones, and the characterisation of microstructural and mechanical properties were also investigated

Novel cuff button antenna for dual-band applications

A wearable antenna that works on two different frequencies is proposed in this paper. A smaller circular patch antenna based on previous research articles is proposed. One of the major attractions of a wearable antenna is its smaller size. The proposed antenna structure is designed by adopting various miniaturization techniques and it resembles a simple cuff button. The radiating structure is square shaped with fillet edges and has a circular-shaped patch. The ground plane extends to the entire plane and therefore, back reflections can be avoided. The substrate used is a Polytetrafluoroethylene PTFE Taconic ceramic substrate whose dielectric permittivity is 10. The substrate has a thickness of 3.18 mm. The substrate is originally rectangular shaped and the shape of a cuff button is achieved by side filleting. The structure is rigid enough to be used as a wearable antenna. The proposed wearable antenna is designed for 2.4 GHz and 5.6 GHz with an omni-directional pattern required for transmission with other wearable devices located across the body. Keywords: Wearable antennas, ISM band, UNII bands, Cuff button antenna, Taconic cerami

Bit error rate test for optical communication link using prbs generated by an fpga - system design

Bit Error Rate Testing(BERT) was implemented using Cyclone III FPGA Starter Kit along with THDB_ADA board and interfaced with several kilometers long optical fiber, to study the link performance of the optical communication system. In this, a single FPGA acts as both transmitter and receiver. The logic to transmit the PRBS bits using LFSR and receive them at the receiver to check for bit errors was implemented

IGWO-SoE: Improved Grey Wolf Optimization Based Stack of Ensemble Learning Algorithm for Anomaly Detection in Internet of Things Edge Computing

With the tremendous growth and popularization of the Internet of Things (IoT), the number of attacks targeting such devices has also increased. Therefore, enhancing the anomaly detection model to maximize detection accuracy and mitigate cyber-attacks in time-critical IoT edge scenarios is essential. Furthermore, there is a lack of vivid, precise, cross-layered, and diverse datasets in IoT for evaluating these anomaly detection models. This paper aims to develop an improved anomaly detection model based on an optimized stacked ensemble learning algorithm at edge computing. Initially, a novel synthetic dataset with multiple cross-layer attacks is generated using the Cooja simulator to train our proposed model. In addition, by introducing an improved grey wolf optimization (IGWO) approach, the parameters of ensemble learning algorithms, such as number of trees, learning rate, and sample rate, are tuned precisely, and the stacking ensemble concept is applied to the optimized ensemble learning algorithms to enhance their prediction capabilities. The experimental results demonstrate that the developed model produces a detection accuracy of 99.44% for our proposed Cooja simulated dataset, which is higher than the contemporary methods. The generalizability of the proposed model is expressed explicitly using four different datasets: NSL KDD, UNSW NB 15, MQTTset, and CICIDS 2017. Finally, we assess the befitting of the proposed model using a chi-square statistical significance test, thereby providing an enriched contribution to the recent works in anomaly detection

Determining the chronological sequence of inks deposited with different writing and printing tools using ion beam analysis

Determining the sequence of inks in a questioned document is important in forensic science. Conventional and micro beam-based ion beam analysis using Rutherford backscattering spectrometry (RBS) and particle-induced X-ray emission were employed to study the depth distribution of chemical elements in plain paper and inks/toner deposited by different pens as well as inkjet and laser printers. Composition depth profiling with high lateral resolution was performed with focus on areas where two different coloring agents overlapped. We identify under which conditions the sequence of inks deposited can be reconstructed, analyzing the continuity of characteristic contributions to the obtained signals, with a focus on the depth-resolved RBS data. The order of deposition was correctly determined for combinations of two different laser printers and in certain cases for pens. Results indicate a potential for analysis, depending on the composition of staining agent, that is, in particular if heavy species are present in sufficiently high concentration. In such cases, also characters obscured or modified by an agent of different composition can be revealed. Changing the probing depth by modifying the beam energy could yield additional information