Metal recycle and recovery

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The development of techniques for the removal and recovery of metals from industrial effluent taking account of the consequences of the definition of waste in the Basel Convention on transfrontier shipment of waste is reported. The use of fluidised bed cell electrolysis in the recovery of metals from dilute solutions is investigated, and the conditions for recovery optimised. For the first time the application of a novel activated carbon cloth concentrator cell to recover metals from effluent solutions is reported and the conditions for its use optimised. Comparative studies using conventional mesh and plate electrodes, and novel activated carbon cloth electrode for the recovery of cobalt from dilute solution, and copper from three different hydrometallurgical solutions viz (i) Cu/Zn, (ii)Cu/Zn/Fe and (iii) Cu/Zn/Cd containing effluents were carried out. Application of concentrator cell technology including activated carbon cloth and ion exchange resin to the recovery of metals, including precious group metals, from industrial as-supplied samples is reported. Optimisation leads to successful recovery of iridium and palladium from very dilute solutions. The alternative recovery of metal as added-value chemicals is also investigated. The Basel Convention is concerned with transfrontier shipment of waste from developed to developing countries and has produced a need to investigate the leachability of metals in various forms. In this work the leachability of copper and zinc is studied under various conditions that model environmental situations and the results have been used to develop a methodology to determine whether a metal containing material would be subject to a shipment ban under the Convention. As part of the development of the methodology, leaching studies were also carried out on single chemical compounds of copper, zinc, cadmium and lead, and their bioavailability determined

AN ANALYSIS OF TAZKARA HAZAR DASTAAN KNOWN AS KHUMKNANAE JAVEED BY LALA SRI RAM

Tazkara is a type of biography in Urdu literature. In Tazkara the researcher compiles the data and events of the lives of poets and other literary personalities. Tazkara Hazar Dastaan known as Khumkhanae Javeed was gathered by Lala Sri Ram. This biography consists of Six volumes. There are 689 pages in Volume 1 and a list of 634 poets according to the Urdu alphabet ا تا بby poetic names included in it. Volume 2 consists of 751 pages with a list of 485 poets by poetic names according to پ تا ح.  Volume 3 consists of 737 pages with a list of 534 poets by poetic names according to خ تا ز. Volume 4 consists of 628 pages with a list of 421 poets by poetic names according to س تا ش. Volume 5 consists of 616 pages with a list of 647 poets by poetic names according to ش تا ع. Volume 6 consists of 556 pages with a list of 458 poets by poetic names according to ع تا ے. There are 3977 pages and 3179 poets in all volumes. It is a remarkable work. In this article, this biography is critically analyzed

Antioxidant, antimicrobial and antiproliferative activities of peel and pulp extracts of red and white varieties of Ipomoea batatas (L) Lam

Purpose: To investigate the antioxidant, antibacterial and anticancer potentials of methanol and ethanol extracts of the peel and pulp of red and white species of Ipomoea batatas (L.) fruit.Methods: Total phenolic contents and flavonoids were determined using chemical assays. Antioxidant studies were carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, inhibition of linoleic acid peroxidation assay and reducing power assay. Antibacterial and antiproliferative activities of extracts were determined using disc diffusion and MDBK cancer cell line inhibition methods, respectively.Results: The extract of peels of red specie (PERS) showed total phenolic contents (TPC) 8.9 mg gallic acid equivalent (GAE)/g dry extract and flavonoids 6.5 mg catechin equivalent (CE)/g dry extract. The extract of PERS also showed promising DPPH free radical scavenging activity, inhibition of linoleic acid peroxidation and reducing power activity. However, mild antibacterial and anti-proliferative activities were noted except that the extract showed significant inhibition of Bacillus subtilis growth.Conclusion: The results indicate that the peel and the pulp of red sweet potato (SP) specie are rich in antioxidants and can potentually be processed as antioxidant food supplements.Keywords: Ipomoea batatas (L.) Lam, Sweet potato, Phenolic content, Antioxidants, Antibacterial activity, Antiproliferative activit

Exploring tourism-generated social media communication, brand equity, satisfaction, and loyalty: A PLS-SEM-based multi-sequential approach

Although social media-based brand equity has become a vital area of interest for brand managers, insights into its destination-based dynamics and applications remain scarce, specifically in the destination brand context. To address this gap, we develop and test a theoretical model to investigate the role of destination marketing organization-generated and tourist-generated social media communication to determine the brand awareness and brand image of the Gilgit-Baltistan region, which in turn influence customer-based brand equity (CBBE) (i.e. perceived quality), satisfaction, and loyalty. Data come from well-known tourist sites in Gilgit-Baltistan. Using the multi-sequential approach in WarpPLS 7.0, findings shows that the social media communication dimensions show differential impacts on brand awareness as a metric of CBBE. Second, destination awareness demonstrates a differential impact on perceived destination image dimensions. Third, the destination image dimensions exert different effects on the perceived quality of the destination. Fourth, perceived quality positively influences satisfaction, which in turn enhances loyalty. We offer important implications that emerged from the analyzes and also suggest directions for future research

Pyridylpiperazine-based carbodithioates as urease inhibitors: synthesis and biological evaluation

The urease enzyme is recognized as a valuable therapeutic agent for treating the virulent Helicobacter pylori bacterium because of its pivotal role in aiding the colonization and growth of the bacterium within the gastric mucosa. In order to control the harmful consequences of bacterial infections, urease inhibition presents itself as a promising and effective approach. The current research aimed to synthesize pyridylpiperazine-based carbodithioate derivatives 5a–5n and 7a–7n that could serve as potential drug candidates for preventing bacterial infections through urease inhibition. The synthesized carbodithioate derivatives 5a–5n and 7a–7n were explored to assess their ability to inhibit the urease enzyme after their structural explication by gas chromatography–mass spectrometry (GC-MS). In the in vitro evaluation with thiourea as a standard drug, it was observed that all the synthesized compounds exhibited significant inhibitory activity compared to the reference drug. Among the compounds tested, 5j (bearing an o-tolyl moiety) emerged as the most effective inhibitor, displaying strong urease inhibition with an IC50 value of 5.16 ± 2.68 μM. This IC50 value is notably lower than that of thiourea (23 ± 0.03 μM), indicating the significantly most potent potential of inhibition. In molecular docking of 5j within the active site of urease, numerous noteworthy interactions were identified

Effect of foliar application of nano-nutrients solution on growth and biochemical attributes of tomato (Solanum lycopersicum) under drought stress

IntroductionDrought stress has drastically hampered the growth and yield of many crops. Therefore, environmentally safe agricultural techniques are needed to mitigate drought stress impact. To this end, foliar spray of nano-nutrients solution to (NNS) alleviate harmful aspects of drought stress.MethodsIn a completely randomized design (CRD) experiment, seedlings were transplanted into pots at 2-3 leaf stage, each filled with loam-compost- organic manure soil (3:1:1). Plants were divided into two groups. (a) control group (b) applied stress group. Plants at vegetative stage were treated with 100% FC for control group and 60% FC for drought group, and these levels were maintained until harvesting. Three treatments of NNS with four levels i.e., 0%, 1%, 3% and 5% were given to all the pots after two weeks of drought stress treatment with a gap of 5 days at vegetative stage.Results and discussionApplication of 1% of nano-nutrient solution displayed an improvement in shoot length, shoot fresh and dry weight, number of leaves and flowers. Leaf chlorophylls and carotenoids and total phenolics contents were found maximum while minimum electrolyte leakage was observed at 3% application compared to control. Further, 1% application of NNS increased the Leaf RWC%, total soluble sugars, flavonoids contents. 5% NNS application exhibited higher total free amino acids with minimum lipid peroxidation rate in leaves of tomato under drought. Antioxidant enzyme activities increased in a concentration dependent manner as gradual increase was observed at 1%, 3% and 5%, respectively. Overall, this study introduced a new insights on using nano-nutrient solutions to maintain natural resources and ensure agricultural sustainabilit

Green Adeptness in the Synthesis and Stabilization of Copper Nanoparticles: Catalytic, Antibacterial, Cytotoxicity, and Antioxidant Activities

Abstract Copper nanoparticles (CuNPs) are of great interest due to their extraordinary properties such as high surface-to-volume ratio, high yield strength, ductility, hardness, flexibility, and rigidity. CuNPs show catalytic, antibacterial, antioxidant, and antifungal activities along with cytotoxicity and anticancer properties in many different applications. Many physical and chemical methods have been used to synthesize nanoparticles including laser ablation, microwave-assisted process, sol-gel, co-precipitation, pulsed wire discharge, vacuum vapor deposition, high-energy irradiation, lithography, mechanical milling, photochemical reduction, electrochemistry, electrospray synthesis, hydrothermal reaction, microemulsion, and chemical reduction. Phytosynthesis of nanoparticles has been suggested as a valuable alternative to physical and chemical methods due to low cytotoxicity, economic prospects, environment-friendly, enhanced biocompatibility, and high antioxidant and antimicrobial activities. The review explains characterization techniques, their main role, limitations, and sensitivity used in the preparation of CuNPs. An overview of techniques used in the synthesis of CuNPs, synthesis procedure, reaction parameters which affect the properties of synthesized CuNPs, and a screening analysis which is used to identify phytochemicals in different plants is presented from the recent published literature which has been reviewed and summarized. Hypothetical mechanisms of reduction of the copper ion by quercetin, stabilization of copper nanoparticles by santin, antimicrobial activity, and reduction of 4-nitrophenol with diagrammatic illustrations are given. The main purpose of this review was to summarize the data of plants used for the synthesis of CuNPs and open a new pathway for researchers to investigate those plants which have not been used in the past. Graphical abstract Proposed Mechanism for Antibacterial activity of copper nanoparticles

Perceived Value of Images Carrying Tourism Location Information on Social Media and Customer Brand Engagement

In this study, we aim to study the factors that affect the perceived value of images carrying the details of tourist locations posted on social networking sites (SNSs) and its effect on customer brand engagement in tourist locations. To empirically test the study model, we collected the data from 155 respondents and 130 were valid for further analysis. The partial least square structural equation modeling (PLS-SEM) approach was used to assess the measurement and structural model. The study results evidenced that the measurement model for study constructs were reliable and sound. Whereas, the results based on the structural model reported that the images posted on SNSs provide entertainment, credibility, and information regarding the tourist locations, which significantly determine the perceived value of images advertised on SNSs. We also found that the perceived value of images successfully predicts the customer brand engagement in images carrying the details