exchange process
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2022 ◽  
Vol 2022 ◽  
pp. 1-14
Author(s):  
Kowit Suwannahong ◽  
Jiyapa Sripirom ◽  
Chadrudee Sirilamduan ◽  
Vanlop Thathong ◽  
Torpong Kreetachart ◽  
...  

This research focused on batch experiment using a new generation of chelating resins via an ion exchange process to describe the metabolic adsorption and desorption capacity onto iminodiacetic acid/Chelex 100, bis-pyridylmethyl amine/Dowex m4195, and aminomethyl phosphonic/Lewatit TP260 functional groups in bioleaching. The results showed that Dowex m4195 had the highest performance of adsorption capacity for copper removal in both H+-form and Na+-form. Results for Lewatit TP260 and Chelex 100 revealed lower adsorption performance than results for Dowex m4195. The investigation of desorption from chelating resins was carried out, and it was found that 2 M ammonium hydroxide concentration provided the best desorption capacity of about 64.86% for the H+-form Dowex m4195 followed by 52.55% with 2 M sulfuric acid. Lewatit with 2 M hydrochloric acid gave the best desorption performance in Na+-form while Chelex 100 using hydrochloric at 1 M and 2 M provided similar results in terms of the H+-form and Na+-form. As aspects of the selective chelating resins for copper (II) ions in aqueous acidic solution generated from synthetic copper-citrate complexes from bioleaching of e-waste were considered, H+-form Dowex m4195 was a good performer in adsorption using ammonium hydroxide for the desorption. However, chelating resins used were subsequently reused for more than five cycles with an acidic and basic solution. It can be concluded from these results that selective chelating resins could be used as an alternative for the treatment of copper (II) ions contained in e-waste or application to other divalent metals in wastewater for sustainable water and adsorbent reuse as circular economy.


2022 ◽  
Author(s):  
Lehlohonolo E. Mphuthi ◽  
Mametsi R. Maseme ◽  
Ernie H.G. Langner

Abstract The metal centres of nano-ZIF-8(Zn) and nano-ZIF-67(Co) were partially exchanged with titanium centres to form bimetallic nZIF-8(Zn/Ti) (52% Ti4+) and nZIF-67(Co/Ti) (38% Ti4+) respectively, for enhanced photocatalytic performance. A morphological and structural analysis by SEM, EDS-Mapping and PXRD showed that the particle size, distribution, and the structural integrity of the Sodalite frameworks of the parent ZIFs were retained during the exchange process to form the new bimetallic Ti-ZIFs. FTIR confirmed that no additional chemical bonds were formed during the process. XPS binding energies confirmed the preservation of the Zn(II), Co(II) and Ti(IV) oxidation states, as well as the Ti-content, consistent with ICP-OES and EDS measurements. The Ti-exchanged ZIFs showed higher activity during the photocatalytic oxidation of hydroquinone in comparison with their parent ZIFs. Their kinetic rates were nearly five times faster than those of the parent ZIFs, with the first-order rate constants k = 0.189 min-1 for nZIF-8(Zn/Ti) and k = 0.139 min-1 for nZIF-67(Co/Ti). These catalysts are efficient, stable, and reusable for three photocatalytic cycles without a significant loss of catalytic activity.


Author(s):  
Ahmed h. Alahmadi

AbstractThe key exchange mechanism in this paper is built utilizing neural network coordination and a hyperchaotic (or chaotic) nonlinear dynamic complex system. This approach is used to send and receive sensitive data between Internet-of-Things (IoT) nodes across a public network. Using phishing, Man-In-The-Middle (MITM), or spoofing attacks, an attacker can easily target sensitive information during the exchange process. Furthermore, minimal research has been made on the exchange of input seed values for creating identical input at both ends of neural networks. The proposed method uses a 5D hyperchaotic or chaotic nonlinear complex structure to ensure the sharing of input seed value across two neural networks, resulting in the identical input on both ends. This study discusses two ways for sharing seed values for neural coordination. The first is a chaotic system with all real variables, whereas the second is a hyperchaotic system with at least one complex variable. Each neural network has its own random weight vector, and the outputs are exchanged. It achieves full coordination in some stages by altering the neuronal weights according to the mutual learning law. The coordinated weights are utilized as a key after the neural coordination technique. The network’s core structure is made up of triple concealed layers. So, determining the inner configuration will be tough for the intruder. The efficiency of the suggested model is validated by simulations, and the findings reveal that the suggested strategy outperforms current equivalent techniques.


2022 ◽  
Vol 961 (1) ◽  
pp. 012098
Author(s):  
Waleed R. Abdullah ◽  
Sali Nabeel Jabrou

Abstract The current study was carried out to improve ionic exchange for potassium in sandy and gypsiferous soils to obtain an increase in absorption of potassium ions in NPK fertilizers, the improving process includes two stages; The first is adding NPK fertilizer with concentrations (0.020%, 0.040%, and 0.070%) by weight for two samples, the exchange potassium concentration was measured and notice the increasing from 124 ppm to 140 ppm in sandy soil and from156 ppm to 180 ppm in gypsiferous soil when using the highest concentration (0.070%), the second stage included adding grinded bentonite ore (10%, 20%,30%) by weight to the two samples after treated with NPK fertilizer in same concentrations above, potassium exchange increased to 340 ppm in sandy soil and to 450 ppm in gypsiferous soil by using NPK fertilizer and bentonite ore concentrate (0.070% & 30%) respectively.


Author(s):  
Lyudmyla M. LUCHKA

Objective. The purpose of the article is to highlight book exchange as an important source of book acquisition process in the libraries of Katerinoslav - Dnipropetrovsk.  The object is libraries of different subordination as a system of collection-forming documents. Methods. Analytical-synthetic, system-structural, comparative and statistical methods are used during the research in accordance with the task. Results. The author revealed the peculiarities of book exchange process in the libraries of educational institutions, scientific societies of Katerynoslavshchyna. The exchange of publications with Kyiv, Galician and Lviv institutions is proved to be useful and important. The author retraced process of cooperation of city public libraries on local literature acquisition. Libraries and reading rooms of higher, secondary and lower agricultural educational institutions received professional publications of Katerinoslav societies free of charge. The article gives a picture of the current state of document exchange in the libraries of Dnipropetrovsk region. The constant source of library acquisition is territorial and domestic professional book exchange. Conclusions. Book exchange is an important component of the process of acquisition of high quality stock in Ukrainian libraries. This prprocess was actively carried out by Katerinoslav libraries in the 19th - early 20th centuries. Throughout history the book exchange has proven to be a necessary and useful source of acquisition and high quality service in the implementation of complex reader requests. Document exchange in the 21st century in Dnipropetrovsk region is changing its format (transition to e-resources), but remains an important source in the process of creating high quality collections.


2021 ◽  
Author(s):  
Alexander Ambrose ◽  
Joshua Detelich ◽  
Maxwell Weinmann ◽  
Frank L. Hammond

Abstract Critical care patients who experience symptoms of acute respiratory distress syndrome are commonly placed on mechanical ventilators to increase the oxygen provided to their pulmonary systems and monitor their condition. With the pulmonary inflammation typically accompanying ARDS, patients can experience lower ventilation-perfusion ratios resulting in lower blood oxygenation. In these cases, patients are typically rotated into a prone position to facilitate improved blood flow to portions of the lung that were not previously participating in the gas exchange process. However, proning a patient increases the risk of complications, requires up to seven hospital staff members to carry out, and does not guarantee an improvement in the patient's condition. The low-cost vest presented here was designed to reproduce the effects of proning while also requiring less hospital staff than the proning process. Additionally, the V/Q Vest helps hospital staff predict whether patients would respond well to a proning treatment. A pilot study was conducted on nine patients with ARDS from Coronavirus disease 2019 (COVID-19). The average increase in oxygenation with the V/Q Vest treatment for all patients was 19.7 ± 38.1%. Six of the nine patients responded positively to the V/Q Vest treatment, exhibiting increased oxygenation. The V/Q Vest also helped hospital staff predict that three of the five patients that were proned would experience an increase in oxygenation. An increase in oxygenation resulting from V/Q Vest treatment exceeded that of the proning treatment in two of these five proned patients.


2021 ◽  
Vol 12 (2) ◽  
pp. 478-502
Author(s):  
Si Van Nguyen ◽  
Minh Vo

The consumer entitlement (CE) construct is a key variable in the exchange process in retail environments. The original Consumer Entitlement Inventory (CEI) was developed and applied within Western cultural boundaries. The main contribution of this study is the extension of the original CEI to better fit the Vietnamese context and to demonstrate its applicability in the context of an emerging economy with a Confucian culture. The study also contributes to expanding the range of identified boycott motives in the literature and clarifying their mechanism via social exchange theory. The extended CEI scale was tested using exploratory factor analysis and confirmatory factor analysis, using a sample of 603 respondents. Qualitative and quantitative research results show that the extended CEI has two dimensions, namely intransigence, and demand and distinction, with adequate content, reliability, convergent validity, and discriminant validity. This study also aimed to apply the extended CEI to an exploration of the relationship between CE and willingness to boycott. Research results from another independent study with 450 respondents using a structural equation model confirmed the positive relationship between CE and willingness to boycott. In addition, theoretical implications are discussed.


Author(s):  
Jingjing Li ◽  
Gen Zhang ◽  
Xinrui Zhang ◽  
Yuhai Zhang ◽  
Zhong Liu ◽  
...  

Abstract The production cross sections of unknown neutron-rich transuranium isotopes of elements Np, Pu, Am and Cm are investigated in multinucleon transfer reactions based on the dinuclear system model with GEMINI code. The influence of the incident energy on the production of neutron-rich transuranium nuclei in actinideactinide collisions is studied. The calculation results show that the final isotopic production cross sections are larger at 1.06-1.10 Vcont than at other energies. Considering the high fissility of transuranium nuclides, 1.06 Vcont is chosen as the optimal incident energy. The N/Z ratio equilibration mechanism in the nucleon transfer process is also studied in this work. The larger difference of N/Z ratio between projectile and target corresponds to larger neutron diffusion during the nucleon exchange process. The 238U beam with high N/Z ratio and neutron-rich actinide targets are good selections to produce neutron-rich transuranium nuclides. The production cross sections of unknown neutron-rich transuranium isotopes 245-249Np, 248-251Pu, 248-254Am, and 252-254Cm are predicted in 238U-induced actinide-based (249Bk, 249Cf, and 252Cf) multinucleon transfer reactions. It is found that a large number of these unknown neutron-rich transuranium nuclei could be generated at the level of nb to µb in the reactions 238U+249Bk and 238U+252Cf. Our research indicates that the reaction 238U+249Bk is a suitable projectile-target combination in the current experimental conditions and the reaction 238U+252Cf could be a promising candidate to produce unknown neutron-rich transuranium nuclides in case that the 252Cf target were to be achieved in the future.


2021 ◽  
pp. 146808742110642
Author(s):  
Sree Harsha Rayasam ◽  
Weijin Qiu ◽  
Ted Rimstidt ◽  
Gregory M Shaver ◽  
Daniel G Van Alstine ◽  
...  

Accurate modeling and control of the gas exchange process in a modern turbocharged spark-ignited engine is critical for the control and analysis of different control strategies. This paper develops a simple physics-based, five-state engine model for a large four-stroke spark-ignited turbocharged engine fueled by natural gas that is used in variable speed applications. The control-oriented model is amenable for control algorithm development and includes the impacts of modulation to any combination of four actuators: throttle valve, bypass valve, fuel rate, and wastegate valve. The control problem requires tracking engine speed to provide propulsive power, differential pressure across the throttle valve to prevent compressor surge, air-to-fuel ratio to restrict engine emissions. Two validation strategies, open-loop and closed-loop, are used to validate the accuracy of both nonlinear and linear versions of the control-oriented model. The control models are able to capture the engine dynamics within 5%–10% error at most of the engine operating points. Finally, the relative gain array (RGA) is applied to the linearized engine model to understand the degree of interactions between plant inputs and outputs as a function of frequency for various operating points. Results of the RGA analysis show that the preferred input-output pairing changes depending on the linear plant model as well as frequency. Therefore, a coordinated controller is ideal to tackle the control problem in question.


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