Search results for: chemical looping partial oxidation of methane

Authors: Bita Bayatsarmadi, Shi-Zhang Qiao

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Oxygen reduction reaction (ORR) performance of iron and nitrogen co-doped porous carbon nanoparticles (Fe-NPC) with various physical and (electro) chemical properties have been investigated. Fe-NPC nanoparticles are synthesized via a facile soft-templating procedure by using Iron (III) chloride hexa-hydrate as iron precursor and aminophenol-formaldehyde resin as both carbon and nitrogen precursor. Fe-NPC nanoparticles shows high surface area (443.83 m2g-1), high pore volume (0.52 m3g-1), narrow mesopore size distribution (ca. 3.8 nm), high conductivity (IG/ID=1.04), high kinetic limiting current (11.71 mAcm-2) and more positive onset potential (-0.106 V) compared to metal-free NPC nanoparticles (-0.295V) which make it high efficient ORR metal-free catalysts in alkaline solution. This study may pave the way of feasibly designing iron and nitrogen containing carbon materials (Fe-N-C) for highly efficient oxygen reduction electro-catalysis.

Keywords: electro-catalyst, mesopore structure, oxygen reduction reaction, soft-template

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Authors: Vijay Kumar, G. K. Grewal, Prasad S. Burange

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India is one of the largest cultivators of cotton in the world. Among the various constraints, insect pests are posing a major hurdle to the success of cotton cultivation. Various bollworms, including the pink bollworm, Pectinophora gossypiella (Saunders), cause serious losses in India, China, Pakistan, Egypt, Brazil, tropical America, and Africa, etc. Bt cotton cultivars having Cry genes were introduced in India in 2002 (Cry1Ac) and 2006 (Cry1Ac+ Cry2Ab) for control of American, spotted, and pink bollworms. Pink bollworm (PBW) larvae infest flowers, squares, and bolls. Larva burrows into flowers and bolls to feed on pollen and seeds, respectively. It has a shorter lifecycle and more generations per year, so it develops resistance more quickly than other bollworms. Further, it has cryptic feeding sites, i.e., flowers and bolls/seeds, so it is not exposed to harsh environmental fluctuations and insecticidal applications. The cry toxin concentration is low in its feeding sites, i.e., seeds and flowers of cotton. The use of insecticide and Bt cotton is the primary control measure that has been successful in limiting the damage of PBW. But with the passage of time, it has developed resistance against insecticides and Bt cotton. However, the use of insecticides increases chemical control costs while causing secondary pest problems and environmental pollution. Extensive research has indicated that monitoring and control measures such as biological, cultural, chemical, and host plant resistance methods can be integrated for effective PBW management. The potential of various biological control organisms needs to be explored. The impact of transgenic cotton on non-target organisms, particularly natural enemies, which play an important role in pest control, is still being debated. According to some authors, Bt crops have a negative impact on natural enemies, particularly parasitoids. An experiment was carried out in the Integrated Pest Management Laboratory of the Department of Entomology, Punjab Agricultural University, Ludhiana, Punjab, India, to study the natural parasitization of PBW on Bt cotton in 2022. A large population of larvae of PBW were kept individually in plastic containers and fed with cotton bolls until the emergence of a parasitoid cocoon. The first cocoon of the parasitoid was observed on October 25, 2022. Symptoms of parasitization were never seen on larvae. Larvae stopped feeding and became inactive before the emergence of parasitoids for pupation. Grub makes its way out of larvae by making a hole in the integument, and immediately after coming out, it spins the cocoon. The adult parasitoid emerged from the cocoon after eight days. The parasitoids that emerged from the cocoon were identified as Cotesia (Braconidae: Hymenoptera) based on the features of the adult. Out of 475 larvae of PBW, 87 were parasitized, with 18.31% of parasitization. Out of these, 6.73% were first instar, 10.52% were second instar, and 1.05% were third instar larvae of PBW. No parasitization was observed in fourth instar larvae. Parasitoids were observed during the fag end of cropping season and mostly on the earlier instars. It is concluded that the potential of Cotesia may be explored as a biological control agent against PBW, which is safer to human beings, environment and non-taraltoget organisms.

Keywords: biocontrol, Bt cotton, Cotesia, Pectinophora gossypiella

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Authors: T. Nouri, Y. H. A. Reguieg, A. Latigui, A. Ouaini

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Salinity is considered as the most important abiotic factor. It limits growth and productivity of plants and degrades agricultural soils and ecosystem in arid and semi arid area. The study was conducted on Vicia faba L.’Semilla violeta’. Sowing was realized in plastic pots containing sandy substrates of bentonite 0, 3, 5, 7, and 10% associated with abiotic stresses of salinity corresponding to doses of NaCl, MgCl2 and MgSO4 20, 40, and 60 mmol/l respectively. The purpose of this work is to study the combined effect of salinity and of bentonite on a plant commonly cultivated in Algeria the broad bean Vicia faba has through the chemical and hydrous parameter. The results show that the combined action of strong concentration salt (40 and 60 mmol/l) and of bentonite a reduction of the relative content water reveals, against an increase in the content of hydrous deficit and of sodium. The growth of broad bean is significant in the substrate amended to 5 % of bentonite.

Keywords: salinity, bentonite, Vicia faba L, sodium content, hydrous parameters

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Authors: V. K. Tewari, M. Hussain, H. K. D. Gupta

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Background: Nitric Oxide Donars (NODs) (intrathecal sodium nitroprusside (ITSNP) and oral tadalafil 20mg post ITSNP) has been studied in this context in cerebral palsy patients for fast recovery. This work proposes two mechanisms for acute cases and one mechanism for chronic cases, which are interrelated, for physiological recovery. a) Retrograde Neurotransmission (acute cases): 1) Normal excitatory impulse: at the synaptic level, glutamate activates NMDA receptors, with nitric oxide synthetase (NOS) on the postsynaptic membrane, for further propagation by the calcium-calmodulin complex. Nitric oxide (NO, produced by NOS) travels backward across the chemical synapse and binds the axon-terminal NO receptor/sGC of a presynaptic neuron, regulating anterograde neurotransmission (ANT) via retrograde neurotransmission (RNT). Heme is the ligand-binding site of the NO receptor/sGC. Heme exhibits > 10,000-fold higher affinity for NO than for oxygen (the 10,000-fold effect) and is completed in 20 msec. 2) Pathological conditions: normal synaptic activity, including both ANT and RNT, is absent. A NO donor (SNP) releases NO from NOS in the postsynaptic region. NO travels backward across a chemical synapse to bind to the heme of a NO receptor in the axon terminal of a presynaptic neuron, generating an impulse, as under normal conditions. b) Vasopasm: (acute cases) Perforators show vasospastic activity. NO vasodilates the perforators via the NO-cAMP pathway. c) Long-Term Potentiation (LTP): (chronic cases) The NO–cGMP-pathway plays a role in LTP at many synapses throughout the CNS and at the neuromuscular junction. LTP has been reviewed both generally and with respect to brain regions specific for memory/learning. Aims/Study Design: The principles of “generation of impulses from the presynaptic region to the postsynaptic region by very potent RNT (10,000-fold effect)” and “vasodilation of arteriolar perforators” are the basis of the authors’ hypothesis to treat cerebral palsy cases. Case-control prospective study. Materials and Methods: The experimental population included 82 cerebral palsy patients (10 patients were given control treatments without NOD or with 5% dextrose superfusion, and 72 patients comprised the NOD group). The mean time for superfusion was 5 months post-cerebral palsy. Pre- and post-NOD status was monitored by Gross Motor Function Classification System for Cerebral Palsy (GMFCS), MRI, and TCD studies. Results: After 7 days in the NOD group, the mean change in the GMFCS score was an increase of 1.2 points mean; after 3 months, there was an increase of 3.4 points mean, compared to the control-group increase of 0.1 points at 3 months. MRI and TCD documented the improvements. Conclusions: NOD (ITSNP boosts up the recovery and oral tadalafil maintains the recovery to a well-desired level) acts swiftly in the treatment of CP, acting within 7 days on 5 months post-cerebral palsy either of the three mechanisms.

Keywords: cerebral palsy, intrathecal sodium nitroprusside, oral tadalafil, perforators, vasodilations, retrograde transmission, the 10, 000-fold effect, long-term potantiation

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Authors: Revoti Prasad Bora, Nikita Katyal, Saurabh Yadav

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Pre-processing plays an important role in various image processing applications. Most of the time due to the similar nature of images, a particular pre-processing or a set of pre-processing steps are sufficient to produce the desired results. However, in the education domain, there is a wide variety of images in various aspects like images with line-based diagrams, chemical formulas, mathematical equations, etc. Hence a single pre-processing or a set of pre-processing steps may not yield good results. Therefore, a Deep Learning based approach for dynamically selecting a relevant pre-processing technique for each image is proposed. The proposed method works as a classifier to detect hidden patterns in the images and predicts the relevant pre-processing technique needed for the image. This approach experimented for an image similarity matching problem but it can be adapted to other use cases too. Experimental results showed significant improvement in average similarity ranking with the proposed method as opposed to static pre-processing techniques.

Keywords: deep-learning, classification, pre-processing, computer vision, image processing, educational data mining

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Authors: Nuray Güy, Mahmut Özacar

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Semiconductor nanoparticles such as TiO₂ and ZnO as photocatalysts are very efficient catalysts for wastewater treatment by the chemical utilization of light energy, which is capable of converting the toxic and nonbiodegradable organic compounds into carbon dioxide and mineral acids. ZnO semiconductor has a wide bandgap energy of 3.37 eV and a relatively large exciton binding Energy (60 meV), thus can absorb only UV light with the wavelength equal to or less than 385 nm. It exhibits low efficiency under visible light illumination due to its wide band gap energy. In order to improve photocatalytic activity of ZnO under visible light, band gap of ZnO may be narrowed by doping such as N, C, S nonmetal ions and coupled two separate semiconductors possessing different energy levels for their corresponding conduction and valence bands. ZnS has a wider band gap (Eg=3.7 eV) than ZnO and generates electron–hole pairs by photoexcitation rapidly. In the present work, N doped ZnO/ZnS nano photocatalysts with visible-light response were synthesized by microwave-hydrothermal method using thiourea as N source. The prepared photocatalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV–visible (UV–vis). The photocatalytic activities samples and undoped ZnO have been studied for the degradation of dye, and have also been compared with together.

Keywords: photocatalyst, synthesis, visible light, ZnO/ZnS

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Authors: T. N. Tran Thi, J. Morse, C. Detlefs, P. K. Cook, C. Yıldırım, A. C. Jakobsen, T. Zhou, J. Hartwig, V. Zurbig, D. Caliste, B. Fernandez, D. Eon, O. Loto, M. L. Hicks, A. Pakpour-Tabrizi, J. Baruchel

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The ability to grow boron-doped diamond epilayers of high crystalline quality is a prerequisite for the fabrication of diamond power electronic devices, in particular high voltage diodes and metal-oxide-semiconductor (MOS) transistors. Boron and intrinsic diamond layers are homoepitaxially overgrown by microwave assisted chemical vapour deposition (MWCVD) on single crystal high pressure, high temperature (HPHT) grown bulk diamond substrates. Various epilayer thicknesses were grown, with dopant concentrations ranging from 1021 atom/cm³ at nanometer thickness in the case of 'delta doping', up 1016 atom/cm³ and 50µm thickness or high electric field drift regions. The crystalline quality of these overgrown layers as regards defects, strain, distortion… is critical for the device performance through its relation to the final electrical properties (Hall mobility, breakdown voltage...). In addition to the optimization of the epilayer growth conditions in the MWCVD reactor, other important questions related to the crystalline quality of the overgrown layer(s) are: 1) what is the dependence on the bulk quality and surface preparation methods of the HPHT diamond substrate? 2) how do defects already present in the substrate crystal propagate into the overgrown layer; 3) what types of new defects are created during overgrowth, what are their growth mechanisms, and how can these defects be avoided? 4) how can we relate in a quantitative manner parameters related to the measured crystalline quality of the boron doped layer to the electronic properties of final processed devices? We describe synchrotron-based techniques developed to address these questions. These techniques allow the visualization of local defects and crystal distortion which complements the data obtained by other well-established analysis methods such as AFM, SIMS, Hall conductivity…. We have used Grazing Incidence X-ray Diffraction (GIXRD) at the ID01 beamline of the ESRF to study lattice parameters and damage (strain, tilt and mosaic spread) both in diamond substrate near surface layers and in thick (10–50 µm) overgrown boron doped diamond epi-layers. Micro- and nano-section topography have been carried out at both the BM05 and ID06-ESRF) beamlines using rocking curve imaging techniques to study defects which have propagated from the substrate into the overgrown layer(s) and their influence on final electronic device performance. These studies were performed using various commercially sourced HPHT grown diamond substrates, with the MWCVD overgrowth carried out at the Fraunhofer IAF-Germany. The synchrotron results are in good agreement with low-temperature (5°K) cathodoluminescence spectroscopy carried out on the grown samples using an Inspect F5O FESEM fitted with an IHR spectrometer.

Keywords: synchrotron X-ray diffaction, crystalline quality, defects, diamond overgrowth, rocking curve imaging

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Authors: Abbas Nasir, Xiong Zhang, Sohail Ahmad, Yiping Cui

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Non-polar a-plane AlGaN epilayers of high structural quality have been grown on r-sapphire substrate by using metalorganic chemical vapor deposition (MOCVD). A graded non-polar AlGaN buffer layer with variable aluminium concentration was used to improve the structural quality of the non-polar a-plane AlGaN epilayer. The characterisations were carried out by high-resolution X-ray diffraction (HR-XRD), atomic force microscopy (AFM) and Hall effect measurement. The XRD and AFM results demonstrate that the Al-composition-graded non-polar AlGaN buffer layer significantly improved the crystalline quality and the surface morphology of the top layer. A low root mean square roughness 1.52 nm is obtained from AFM, and relatively low background carrier concentration down to 3.9×  cm^-3 is obtained from Hall effect measurement.

Keywords: non-polar AlGaN epilayer, Al composition-graded AlGaN layer, root mean square, background carrier concentration

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Authors: Y. M. Al-Wahaibi, S. N. Al-Bahry, A. E. Elshafie, A. S. Al-Bemani, S. J. Joshi, A. K. Al-Bahri

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Crude oil is a major source of global energy. The major problem is its widespread use and demand resulted is in increasing environmental pollution. One associated pollution problem is ‘oil spills’. Oil spills can be remediated with the use of chemical dispersants, microbial biodegradation and microbial metabolites such as biosurfactants. Four different minimal salt media for biosurfactant production by Bacillus isolated from oil contaminated sites from Oman were screened. These minimal salt media were supplemented with either glucose or sucrose as a carbon source. Among the isolates, W16 and B30 produced the most active biosurfactants. Isolate W16 produced better biosurfactant than the rest, and reduced surface tension (ST) and interfacial tension (IFT) to 25.26mN/m and 2.29mN/m respectively within 48h which are characteristics for removal of oil in contaminated sites. Biosurfactant was produced in bulk and extracted using acid precipitation method. Thin Layer Chromatography (TLC) of acid precipitate biosurfactant revealed two concentrated bands. Further studies of W16 biosurfactant in bioremediation of oil spills are recommended.

Keywords: oil contamination, remediation, Bacillus spp, biosurfactant, surface tension, interfacial tension

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Authors: Imana Shahrin Tania, Mohammad Ali

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The present study reports the synthesis, characterization and application of nano-sized zinc-oxide (ZnO) particles on a cotton fabric surface. The aim of the investigations is to impart the antimicrobial activity on textile cloth. Nanoparticle is synthesized by wet chemical method from zinc sulphate and sodium hydroxide. SEM (scanning electron micrograph) images are taken to demonstrate the surface morphology of nanoparticles. XRD analysis is done to determine the crystal size of the nanoparticle. With the conformation of nanoformation, the cotton woven fabric is treated with ZnO nanoparticle by mechanical thermo-fixation (pad-dry-cure) technique. To increase the wash durability of nano treated fabric, an acrylic binder is used as a fixing agent. The treated fabric shows up to 90% bacterial reduction for S. aureus (Staphylococcus aureus) and 87% for E. coli (Escherichia coli) which is appreciable for bacteria protective clothing.

Keywords: nanoparticle, zinc oxide, cotton fabric, antibacterial activity, binder

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Authors: Reim A. Almotiri, Manal M. Alkhamisi

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Ternary nanocomposites based on hydroxyapatite (HAP) and alumina (Al2O3) were embedded through graphene oxide (GO) nanosheets to be investigated for medical applications. The composition of the preparations has been confirmed by X-ray photoelectron spectroscopy, energy-dispersive X-ray analysis, and Fourier-Transform infrared spectroscopy. Scanning and transmission electron microscopy have shown the typical morphologies of the components of the nanocomposites with hydroxyapatite nanorods reaching an average diameter of 22.26±2 nm and an average length of 69.56±19.25 nm in the ternary nanocomposites. The ternary nanocomposite has a microhardness of 5.8±0.1 GPa and a higher average roughness of 6.5 nm compared to pure HAP preparation with an average roughness of 2.7 nm. All preparations have shown an acceptable cytotoxicity profile with a percent osteoblasts cell viability of 98.6±1.3% after culturing with the ternary nanocomposite. The TNC has also shown the highest antibacterial activity compared to preparations of each of its constituents and their nanocomposites, with a zone of inhibition’s diameter of 14.1±0.8 mm and 13.6±0.6 mm against Staphylococcus aureus and Escherichia coli, respectively, compared to no zone of inhibition for the pure hydroxyapatite preparation.

Keywords: hydroxypatite, cytotoxicity, nanocomposites, X-ray analysis

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Authors: Diana G. Ramirez-Wong, Marius Ramirez, Regina Sanchez-Leija, Adriana Rugerio, R. Araceli Mauricio-Sanchez, Martin A. Hernandez-Landaverde, Arturo Carranza, John A. Pojman, Josue D. Mota-Morales, Gabriel Luna-Barcenas

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Chitin films were prepared using alpha-chitin from shrimp shells as raw material and a simple method of precipitation-evaporation. Choline chloride: urea Deep Eutectic Solvent (DES) was used to disperse chitin and compared against hexafluoroisopropanol (HFIP). A careful analysis of the chemical and crystalline structure was followed along the synthesis of the films, revealing crystalline-phase transitions. The full conversion of alpha- to beta-, or alpha- to gamma-chitin structure were detected by XRD and NMR on the films. The synthesis of highly crystalline monophasic gamma-chitin films was achieved using a DES; whereas HFIP helps to promote the beta-phase. These results are encouraging to continue in the study of DES as good processing media to control the final properties of chitin based materials.

Keywords: chitin, deep eutectic solvent, polymorph, phase transformation

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Authors: Nur Zahidah Rozaki, Desmond Ang Teck Chye

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Environment-friendly polymeric plasticisers for poly(vinyl chloride), PVC were synthesised using palm oil as the main raw material. The synthesis comprised of 2 steps: (i) transesterification of palm oil, followed by (ii) polycondensation between the products of transesterification with diacids. The synthesis involves four different formulations to produce plasticisers with different average molecular weight. Chemical structures of the plasticiser were studied using FTIR (Fourier-Transformed Infra-Red) and 1H-NMR (Proton-Nuclear Magnetic Resonance).The molecular weights of these palm oil-based polymers were obtained using GPC (Gel Permeation Chromatography). PVC was plasticised with the polymeric plasticisers through solvent casting technique using tetrahydrofuran, THF as the mutual solvent. Some of the tests conducted to evaluate the effectiveness of the plasticiser in the PVC film including thermal stability test using thermogravimetric analyser (TGA), differential scanning calorimetry (DSC) analysis to determine the glass transition temperature, Tg, and mechanical test to determine tensile strength, modulus and elongation at break of plasticised PVC using standard test method ASTM D882.

Keywords: alkyd, palm oil, plasticiser, pvc

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Authors: Monireh Movahedi

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Considering undesirable effects of chemical insecticides on environment and human health, most studies focused on insecticidal effects of plant materials. Here, the insecticidal effects of methanol, ethylacetat and n-Hexan extracts of Rosmarinus officinalis L. on larval stage of the cotton bollworm were studied. From each extract, six concentrations, including 5, 10, 20, 40 and 60 mg/ml were prepared and added on larval artificial diet. Moreover, solution of distilled water and tween 2% considered as check treatment. All experiments were done in laboratory temperature of 25±3 ºC, RH =50±10% and natural photoperiod during growing season. Each treatment had four replications and each replication carried out on 10 first instar larva with <24h age. Larval mortality was recorded 3 and 7 days after treat. Based on results, LC50 of methanol, ethylacetat and n-Hexan extracts of R. officinalis were 2.78, 15.87 and 15.70 ml/mg, respectively. On the other hand, antifeedant effect of methanol, ethylacetat and n-Hexan for R. officinalis estimated as 43.13%, 55.11% and 9.19%, respectively. All the obtained results revealed that methanol and ethylacetat extracts of R. officinalis are effective extracts for controlling the cotton bollworm population.

Keywords: Helocoverpa armigera, Rosemarinus officinalis, extract, methanol, ethylacetat, n-Hexan

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Authors: Ali Kara, Asim Olgun, Sevgi Sozugecer, Sahin Ozel, Kubra Nur Yildiz, P. Sevinç, Abdurrahman Kuresh, Guliz Turhan, Duygu Gulgun

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The synthetic dyes, one of the most hazardous chemical compound classes, are important potential water pollutions since their presence in water bodies reduces light penetration, precluding the photosynthesis of aqueous flora and causing various diseases. Some the synthetic dyes are highly toxic and/or carcinogenic, and their biodegradation can produce even more toxic aromatic amines. The adsorption procedure is one of the most effective means of removing synthetic dye pollutants, and has been described in a number of previous studies by using the functional polymers. In this study, we investigated the removal of synthetic dyes from aqueous solution by using a functional polymer as an adsorbent material. The effect of initial solution concentration, pH, and contact time on the adsorption capacity of the adsorbent were studied in details. The results showed that functional polymer has a potential to be used as cost-effective and efficient adsorbent for the treatment of aqueous solutions from textile industries.

Keywords: functional polymers, synhetic dyes, adsorption, physicochemical parameters

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Authors: Weijie Gu, Sergio Martinez, Hoai Nguyen, Hongtao Xu, Piet Herdewijn, Steven De Jonghe, Kalyan Das

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Nucleotide analogs are used for treating viral infections such as HIV, hepatitis B, hepatitis C, influenza, and SARS-CoV-2. To become polymerase substrates, a nucleotide analog must be phosphorylated by cellular kinases, which are rate-limiting. The goal of this study is to develop dNTP/NTP analogs directly from nucleotides. Tenofovir (TFV) analogs were synthesized by conjugating with natural or unnatural amino acids. It demonstrates that some conjugates act as dNTP analogs, and HIV-1 reverse transcriptase (RT) catalytically incorporates the TFV part as the chain terminator. X-ray structures in complex with HIV-1 RT/dsDNA showed binding of the conjugates at the polymerase active site, however, in different modes in the presence of Mg²⁺ vs. Mn²⁺ ions. The adaptability of the compounds is seemingly essential for catalytic incorporation of TFV by RT. 4d with a carboxyl sidechain demonstrated the highest incorporation. 4e showed weak incorporation and rather behaved as a dNTP-competitive inhibitor. This result advocates the feasibility of designing NTP/dNTP analogs by chemical substitutions to nucleotide analogs.

Keywords: dNTP analogs, nucleotide analogs, polymerase, tenofovir, X-ray structure

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Authors: O. Benturki, A. Benturki

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Activated carbon was prepared from Jujube seeds by chemical activation with potassium hydroxide (KOH), followed by pyrolysis at 800°C. Batch studies were conducted for kinetic, thermodynamic and equilibrium studies on the adsorption of phenol (P) and 2-4 dichlorophenol (2-4 DCP) from aqueous solution, than the adsorption capacities followed the order of 2-4 dichlorophenol > phenol. The operating variables studied were initial phenols concentration, contact time, temperature and solution pH. Results show that the pH value of 7 is favorable for the adsorption of phenols. The sorption data have been analyzed using Langmuir and Freundlich isotherms. The isotherm data followed Langmuir Model. The adsorption processes conformed to the pseudo-second-order rate kinetics. Thermodynamic parameters such as enthalpy, entropy and Gibb’s free energy changes were also calculated and it was found that the sorption of phenols by Jujuba seeds activated carbon was a spontaneous process The maximum adsorption efficiency of phenol and 2-4 dichlorophenol was 142.85 mg.g−1 and 250 mg.g−1, respectively.

Keywords: activated carbon, adsorption, isotherms, Jujuba seeds, phenols, langmuir

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Authors: Mir Shahnawaz Jagirani, Aziza Aftab, Noorullah Soomro, Syed Farman Ali Shah, Kambiz Vafai

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Utilization of indigenous adsorbent bed of power plant waste ash briquettes, a porous medium was used first time in Pakistan for low cost treatment facility for the toxic effluent of a dyes manufacturing plant effectively and economically. This could replace costly treatment facilities, such as reverse osmosis (RO) and the beds, containing imported and commercial grade expensive Granulated Activated Carbon (GAC).This bed was coupled with coagulants (Ferrous Sulphate and Lime) and found more effective. The coal fired ash (CFA) was collected from coal fired boilers of Lakhra Power Generation Company, Jamshoro, Pakistan. The use of this bed resolved the disposal and environmental issues and treated waste water of chemicals, dyes and pigment manufacturing plant. The bed reduced COD, color, turbidity and TSS remarkably. An adsorptive capacity and chemical behavior of fly ash bed was also studied. In coagulation treatment alone, elimination of COD by 32%, color by 48%, and turbidity by 50% and TSS by 51% respectively. When the bed was coupled with coagulants, it resulted an excessive removal of Color 88%, TSS 92%, COD 67% and Turbidity 89%. Its regeneration was also inexpensive and simple.

Keywords: coal fly ash, spheres, dyes, wastewater

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Authors: Ke Lin, Steve Wu Qing Yang, Zhang Nan

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The medicine and drugs has in the past been manufactured to the final products and then used laboratory analysis to verify their quality. However the industry needs crucially a monitoring technique for the final batch to batch quality check. The introduction of process analytical technology (PAT) provides an incentive to obtain real-time information about drugs on the production line, with the following optical techniques being considered: near-infrared (NIR) spectroscopy, Raman spectroscopy and imaging, mid-infrared spectroscopy with the use of chemometric techniques to quantify the final product. However, presents problems in that the spectra obtained will consist of many combination and overtone bands of the fundamental vibrations observed, making analysis difficult. In this work, we describe a non-destructive system and method for capsule and liquid medicine identification, more particularly, using terahertz time-domain spectroscopy and/or designed terahertz portable system for identifying different types of medicine in the package of capsule or in liquid medicine bottles. The target medicine can be detected directly, non-destructively and non-invasively.

Keywords: terahertz, non-destructive, non-invasive, chemical identification

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Authors: Redhouane Benfares, Kamel Boudjemaa, Affaf Kord, Sonia Messis, Linda Farai, Belkacem Guenachi, Kherarba Maha, Jaroslava ŠVarc-Gajić

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In recent years valorization of biowaste has attracted a lot of attention worldwide owing to its high nutritional value and low price. In this work, biowaste of animal (sardines) and plant (tomato) biowaste was used to formulate a new feed for red tilapia that showed to be competitive in its price, and zootechnical performance in comparison to commercially available tilapia feeds. Mathematical modelling was used to formulate optimal feed composition with favorable chemical composition and the lowest price. Formulated feed had high protein content (40.76%) and an energy value of 279.6 Kcal/100 g. Optimised feed was manufactured and compared to commercially available reference feed with respect to feeding intake, feed efficiency, the specific growth rate of fingerlings of Tilapia sp, and, most important, zootechnical parameters. With a fish survival rate of 100% calculated feed conversion index for the formulated feed was 2.7.

Keywords: conversion index, fish waste, formulated feed, tomato waste

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Authors: Bai Zhiwei, Zhang Shuxia

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By sealing constraint, the system of nuclear fuel production penetrates a trace of air in during its service. The vapor in the air can react with material in the system and generate solid uranium compounds. These solid uranium compounds continue to accumulate and attached to the production equipment and pipeline of system, which not only affects the operation reliability of production equipment and give off radiation hazard as well after system retired. Therefore, it is necessary to select a reasonable method to remove it. Through the analysis of physicochemical properties of solid uranium compounds, halogenated fluoride compounds are selected as a cleaning agent, which can remove solid uranium compounds effectively. This paper studied the related chemical reaction under the condition of static test and results show that the selection of high fluoride halogen compounds can be removed solid uranium compounds completely. The study on the influence of reaction pressure with the reaction rate discovered a phenomenon that the higher the pressure, the faster the reaction rate.

Keywords: fluoride halogen compound, remove, radiation, solid uranium compound

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Authors: Yong Pan, Li Wang, Xue Qiong Su, Dong Wen Gao

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To date, nanomaterials have received extensive attention over the years because of their wide application. Various nanomaterials such as nanoparticles, nanowire, nanoring, nanostars and other nanostructures have begun to be systematically studied. The preparation of these materials by chemical methods is not only costly, but also has a long cycle and high toxicity. At the same time, preparation of nanoparticles of multi-doped composites has been limited due to the special structure of the materials. In order to prepare multi-doped composites with the same structure as macro-materials and simplify the preparation method, the Ga_xCo_1-xZnSe_0.4 (x = 0.1, 0.3, 0.5) nanoparticles are prepared by Pulse Laser Ablation (PLA) method. The particle component and structure are systematically investigated by X-ray diffraction (XRD) and Raman spectra, which show that the success of our preparation and the same concentration between nanoparticles (NPs) and target. Morphology of the NPs characterized by Transmission Electron Microscopy (TEM) indicates the circular-shaped particles in preparation. Fluorescence properties are reflected by PL spectra, which demonstrate the best performance in concentration of Ga_0.3Co_0.3ZnSe_0.4. Therefore, all the results suggest that PLA is promising to prepare the multi-NPs since it can modulate performance of NPs.

Keywords: PLA, physics, nanoparticles, multi-doped

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Authors: Maryam Firouzmandi, Moosa Miri

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Common reasons for early tooth loss are trauma, extraction due to caries or periodontal disease and congenital missing. The remaining space after tooth loss may cause functional and esthetic problems. Therefore restorative dentists should attempt to manage these spaces using conservative methods. The goal is to restore the lost esthetic and function, prevent phonetic, self-esteem and personality problems and tongue habits. Preserving alveolar bone is also of great importance during the growth stage. Purpose: When deciding about the management of the missing tooth, space implants are contradicted until the completion of dentoalveolar development. Even in adulthood, due to systemic or periodontal problems or biological and economic issues, the implant might not be indicated. In this article, the alternative conservative restorative methods of space maintenance are going to be discussed. Essix retainers are made chair-side as easy as forming a custom bleaching tray with some modifications. They are esthetically acceptable and not expensive. These temporaries provide support for the lips but could not be used during function. Mini-screw-supported temporaries are another option for maintaining the space, especially after orthodontic treatment when there is a time lag between the termination of orthodontic treatment and definitive restoration. Two techniques will be presented for this kind of restoration: Denture tooth pontic or a composite crown. The benefits are alveolar bone preservation, Physiologic pressure on the alveolar ridge to increase its density and even can be retained until the completion of the definitive treatment. Bonded fixed partial denture includes Maryland bridge, fiber-reinforced composite bridge, resin-bonded bridge, and ceramic bonded bridge. These types of bridges are recommended to be used after a pubertal growth spurt and a recent meta-analysis considered their clinical success similar to conventional FDPs and implant-supported crowns. However, they have several advantages that are going to be discussed by presenting some clinical examples. Practical instruction on how to construct an FRC bridge and a novel chair-side Maryland bridge will be given by means of clinical cases. Clinical relevance: minimally invasive options should always be considered and destruction of healthy enamel and dentin during the preparation phase should be avoided as much as possible.

Keywords: tooth missing, fiber-reinforced composite, Maryland, Essix retainers, screw-retained restoration

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Authors: H. M. Wang, C. J. Chang

Abstract:

As the threat of global climate change is more seriously, "net zero emissions by 2050" has become a common global goal. In order to reduce the consumption of petrochemical raw materials and reduce carbon emissions, low-carbon fiber materials have become key materials in the future global textile supply chain. This project uses polyolefin raw materials to modify through synthesis and amination to develop low-temperature dyeable polypropylene fibers, endow them with low-temperature dyeability and high color fastness that can be combined with acid dyes, and improve the problem of low coloring strength. The color fastness to washing can reach the requirement of commerce with 3.5 level or more. Therefore, we realize the entry of polypropylene fiber into the clothing textile supply chain, replace existing fiber raw materials, solve the problem of domestic chemical fiber, textile, and clothing industry's plight of no low-carbon alternative new material sources, and provide the textile industry with a solution to achieve the goal of net zero emissions in 2050.

Keywords: acid dyes, dyeing, low-temperature, polypropylene fiber

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Authors: Soroor Ghaziof, Wei Gao

Abstract:

Zn alloy and composite coatings are widely used in buildings and structures, automobile and fasteners industries to protect steel component from corrosion. In this paper, Zn-Ni-Al2O3 nano-composite coatings were electrodeposited on mild steel using a novel sol enhanced electroplating method. In this method, transparent Al2O3 sol was added into the acidic Zn-Ni bath to produced Zn-Ni-Al2O3 nano-composite coatings. The effect of alumina sol on the electrodeposition process, and coating properties was investigated using cyclic voltammetry, XRD, ESEM and Tafel test. Results from XRD tests showed that the structure of all coatings was single γ-Ni5Zn21 phase. Cyclic voltammetry results showed that the electrodeposition overpotential was lower in the presence of alumina sol in the bath, and caused the reduction potential of Zn-Ni to shift to more positive values. Zn-Ni-Al2O3 nano composite coatings produced more uniform and compact deposits, with fine grained microstructure when compared to Zn-Ni coatings. The corrosion resistance of Zn-Ni coatings was improved significantly by incorporation of alumina nano particles into the coatings.

Keywords: Zn-Ni-Al2O3 composite coatings, steel, sol-enhanced electroplating, corrosion resistance

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Authors: Gloria P. Manu, Johnson K. Efavi, Abu Yaya, Grace K. Arkorful, Frank Godson

Abstract:

Plastics have been used extensively in both food and water packaging and other applications because of their inherent properties of low bulk densities and inertness as well as its low cost. Waste management of these plastics after usage is troubling in Ghana. One way of addressing the environmental problems associated with these plastic wastes is by recycling into useful products such as composites for energy and construction applications using natural or local materials as reinforcement. In this work, composites have been formed from waste low-density polyethylene (LDPE) and kaolin at temperatures as low as 70 ֯C using low-cost solvents like kerosene. Chemical surface modifications have been employed to improve the interfacial bonding resulting in the enhancement of properties of the composites. Kaolin particles of sizes ≤ 90µm were dispersed in the polyethylene matrix. The content of the LDPE was varied between 10, 20, 30, 40, 50, 60, and 70 %wt. Results obtained indicated that all the composites exhibited impressive compressive and flexural strengths with the 50%wt. composition having the highest strength. The hardness value of the composites increased as the polyethylene composition reduces and that of the kaolin increased. The average density and water of absorption of the composites were 530kg/m³ and 1.3% respectively.

Keywords: polyethylene, recycling, waste, composite, kaolin

Procedia PDF Downloads 157

Authors: Abderrahmane Hamdi, Julie Chalon, Benoit Dodin, Philippe Champagne

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This research work concerns the synthesis of hydrophobic and self-cleaning coatings as an alternative to fluorine-based coatings used on glass. The developed, highly transparent coatings are produced by a chemical route (sol-gel method) using two silica-based precursors, hexamethyldisilazane and tetraethoxysilane (HMDS/TEOS). The addition of zinc oxide nanoparticles (ZnO NPs) within the gel provides a photocatalytic property to the final coating. The prepared gels were deposited on glass slides using different methods. The properties of the coatings were characterized by optical microscopy, scanning electron microscopy, UV-VIS-NIR spectrophotometer, and water contact angle method. The results show that the obtained coatings are homogeneous and have a hydrophobic character. In particular, after thermal treatment, the HMDS/TEOS@ZnO charged gel deposited on glass constitutes a coating capable of degrading methylene blue (MB) under UV irradiation. Optical transmission reaches more than 90% in most of the visible light spectrum. Synthetized coatings have also demonstrated their mechanical durability and self-cleaning ability.

Keywords: coating, durability, hydrophobicity, sol-gel, self-cleaning, transparence

Procedia PDF Downloads 145

Authors: Santos Maza, Enzo Aldoradin, Carlos Pariona, Eliud Arpi, Maria Rosales

Abstract:

The objective of this study was to investigate the effect of flaying then bleeding anchovy (Engraulis ringens) immersed within a sodium citrate solution. Anchovy is a pelagic fish that readily deteriorates due to its high content of polyunsaturated fatty acids. As such, within the Peruvian food industry, the shelf life of frozen anchovy is explicitly 6 months, this short duration imparts a barrier to use for direct consumption human. Thus, almost all capture of anchovy by the fishing industry is eventually used in the production of fishmeal. We offer this an alternative to its typical production process in order to increase shelf life. In the present study, 100 kg of anchovies were captured and immediately mixed with ice on ship, maintaining a high quality sensory metric (e.g., with color blue in back) while still arriving for processing less than 2 h after capture. Anchovies with fat content of 3% were immediately flayed (i.e., reducing subcutaneous fat), beheaded, gutted and bled (i.e., removing hemoglobin) by immersion in water (Control) or in a solution of 2.5% sodium citrate (treatment), then subsequently frozen at -30 °C for 8 h in 2 kg batches. Subsequent glazing and storage at -25 °C for 14 months completed the experiments parameters. The peroxide value (PV), acidity (A), fatty acid profile (FAP), thiobarbituric acid reactive substances (TBARS), heme iron (HI), pH and sensory attributes of the samples were evaluated monthly. The results of the PV, TBARS, A, pH and sensory analyses displayed significant differences (p<0.05) between treatment and control sample; where the sodium citrate treated samples showed increased preservation features. Specifically, at the beginning of the study, flayed, beheaded, gutted and bled anchovies displayed low content of fat (1.5%) with moderate amount of PV, A and TBARS, and were not rejected by sensory analysis. HI values and FAP displayed varying behavior, however, results of HI did not reveal a decreasing trend. This result is indicative of the fact that levels of iron were maintained as HI and did not convert into no heme iron, which is known to be the primary catalyst of lipid oxidation in fish. According to the FAP results, the major quantity of fatty acid was of polyunsaturated fatty acid (PFA) followed by saturated fatty acid (SFA) and then monounsaturated fatty acid (MFA). According to sensory analysis, the shelf life of flayed, beheaded and gutted anchovy (control and treatment) was 14 months. This shelf life was reached at laboratory level because high quality anchovies were used and immediately flayed, beheaded, gutted, bled and frozen. Therefore, it is possible to maintain the shelf life of anchovies for a long time. Overall, this method displayed a large increase in shelf life relative to that commonly seen for anchovies in this industry. However, these results should be extrapolated at industrial scales to propose better processing conditions and improve the quality of anchovy for direct human consumption.

Keywords: citrate sodium solution, heme iron, polyunsaturated fatty acids, shelf life of frozen anchovy

Procedia PDF Downloads 278

Authors: Princes Ann E. Prieto, Denise F. Alpuerto, John Rafael C. Unlayao, Neil Concibido, Monet Concepcion Maguyon-Detras

Abstract:

Failure Mode and Effects Analysis (FMEA) has been used in the virtual Process Hazard Analysis (PHA) of the Acetone production process through the dehydrogenation of isopropyl alcohol, for which very limited process risk assessment has been published. In this study, the potential failure modes, effects, and possible causes of selected major equipment in the process were identified. During the virtual FMEA mock sessions, the risks in the process were evaluated and recommendations to reduce and/or mitigate the process risks were formulated. The risk was estimated using the calculated risk priority number (RPN) and was classified into four (4) levels according to their effects on acetone production. Results of this study were also used to rank the criticality of equipment in the process based on the calculated criticality rating (CR). Bow tie diagrams were also created for the critical hazard scenarios identified in the study.

Keywords: chemical process safety, failure mode and effects analysis (FMEA), process hazard analysis (PHA), process safety management (PSM)

Procedia PDF Downloads 120

Authors: S. R. Parthiban, C. Elajchet Senni

Abstract:

Spiral heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. An innovative spiral heat exchanger based on polymer materials is designed for waste heat recovery process. Such a design based on polymer film technology provides better corrosion and chemical resistance compared to conventional metal heat exchangers. Due to the smooth surface of polymer film fouling is reduced. A new arrangement for flow of hot flue gas and cold fluid is employed for design, flue gas flows in axial path while the cold fluid flows in a spiral path. Heat load recovery achieved with the presented heat exchanger is in the range of 1.5 kW thermic but potential heat recovery about 3.5kW might be achievable. To measure the performance of the spiral tube heat exchanger, its model is suitably designed and fabricated so as to perform experimental tests. The paper gives analysis of spiral tube heat exchanger.

Keywords: spiral heat exchanger, polymer based materials, fouling factor, heat load

Procedia PDF Downloads 354