Synthesis of selective biodegradable amidoxime chitosan for absorption of Th(IV) and U(VI) ions in solution

2021 ◽  
Vol 109 (5) ◽  
pp. 343-355
Author(s):  
Jiaju Ma ◽  
Zhiwei Lei ◽  
Yun Zhou ◽  
Tianhao Dong ◽  
Peizhuo Hu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Adsorption Process ◽  
Crosslinking Agent ◽  
Post Treatment ◽  
Batch Adsorption ◽  
Element Analysis ◽  
One Step ◽  
Ft Ir ◽  
Harmful Substances

Abstract Radionuclide extraction from wastewater is a long-term process, in which the study on the reuse and decomposition of adsorbents provides the ability to complete the post-treatment after adsorption. Herein, A novel biodegradable amidoxime chitosan has been synthesized through one-step without crosslinking agent and characterized by FT-IR, SEM, XPS, TGA and element analysis. The batch adsorption experiments of U(VI) and Th(IV) on AO-CTS adsorbent were studied and maximum adsorption of U(VI) and Th(IV) were 97 and 56 mg/g, respectively. The U(VI) and Th(Ⅳ) can be effectively desorbed from the AO-CTS materials at low acidity, The AO-CTS can be reused 6 times without reducing absorbency for U(VI) and Th(Ⅳ). When finish the adsorption process, the AO-CTS can be degraded by lysozyme at room temperature, there were no toxic or harmful substances are produced.

Finite Element Analysis and Experimental Study of an Electromagnetic Shell Part with Flow Control Forming

2013 ◽  
Vol 690-693 ◽  
pp. 2982-2989
Author(s):  
Zhi Wei Huang ◽  
Yuan Yuan Wan ◽  
Yan Bin Wang ◽  
Lu Chang Che ◽  
Chuan Lin Liu ◽  
...  
Keyword(s):  
Flow Control ◽  
Room Temperature ◽  
Steel Sheet ◽  
Equivalent Stress ◽  
Metal Flow ◽  
Practical Method ◽  
Element Analysis ◽  
One Step ◽  
Simulation Results ◽  
Shell Part

In this paper, an electromagnetic shell part was studied with the design of die, simulation and the flow control forming (FCF) method. The important technology of FCF was the design of cavity die to control metal flow. The simulation results indicate that pyramidal faces of cavity die exerted a significant influence on qualities of parts. The simulation results also revealed that the effective stresses of the sheet were inhomogeneous and the distributions of the equivalent stress were lamellar with obvious gradients. Experimental results show that steel sheet (08Al) could be formed in one step into intricate shapes at room temperature. This confirmed that FCF is a safe, clean and practical method for the near net forming of parts.

Room Temperature Synthesis and Characterization of Au Nanoparticles

2010 ◽  
Vol 159 ◽  
pp. 303-306
Author(s):  
Sharmin Haq ◽  
Tasnuva Ashrafee ◽  
Mahmuda Begum ◽  
Tasmia Sharmin ◽  
Nirban Bhowmick ◽  
...  
Keyword(s):  
Room Temperature ◽  
Cost Effective ◽  
Nano Particles ◽  
Emergent Properties ◽  
Temperature Synthesis ◽  
Room Temperature Synthesis ◽  
Potential Applications ◽  
One Step ◽  
Ft Ir ◽  
Photo Detection

The new emergent properties of nanoparticles include quantam size effect, nonlinear optical properties and thus the nanomaterials have extensive applications in microelectronic, bacteriostatic and catalytic or magnetic recording materials. Nanoparticles find potential applications in DNA detection and photo detection. Gold nano particles (AuNPs) are useful in nanoscale devices and systems due to its resistance to oxidation. In this paper a cost effective, versatile and simple one step room temperature synthesis of highly stable and freestanding Au quantum dots capped by TTAB (Tetradecyltrimethyl Amonium Bromide) in the range of 10-90 nm is reported. Ultraviolet- visible spectroscopy (UV-VIS), Fourier transformation infrared spectroscopy (FT-IR) was carried out to characterize these samples. Scanning Electron Microscopy (SEM) confirms the AuNPs sizes of about 80 and 88 nm.

Preparation of Nano-MnO2 and Adsorption of Reactive Brilliant Blue

2016 ◽  
Vol 847 ◽  
pp. 294-298
Author(s):  
Xiao Feng Fan ◽  
Yue Cheng
Keyword(s):  
Reaction Time ◽  
Room Temperature ◽  
Particle Diameter ◽  
Solution Concentration ◽  
Brilliant Blue ◽  
Uniform Size ◽  
Initial Concentration ◽  
One Step ◽  
Ft Ir ◽  
Xrd Patterns

MnO2 nanoparticles were prepared by one-step redox under room temperature. The sample was characterized by XRD, SEM, TEM and FT-IR. The results indicated that the MnO2 nanoparticles was amorphous δ-MnO2 with the uniform size of 10-20nm in particle diameter, which can be seen by XRD patterns. The four peaks appear at 2θ = 23.24°,36.1°,45.42°and 64.38°, respectively. FT-IR results showed the 519 cm-1 as Mn-O features manganese dioxide absorption. The effect of the pH, nanoMnO2 dosage, reaction time, reaction temperature and initial concentration were studied on the removal of reactive brilliant blue. It was found that the removal ability of reactive brilliant blue was the best under the selected conditions: pH was 3.0, dosage of nanoMnO2 was 0.05g, KN-R solution concentration was 5mg / L, reaction time was 2h, temperature was 25°C.

Annealing-free and strongly adhesive silver nanowire networks with long-term reliability by introduction of a nonconductive and biocompatible polymer binder

Nanoscale ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 4812-4818 ◽  
Author(s):  
Yunxia Jin ◽  
Dunying Deng ◽  
Yuanrong Cheng ◽  
Lingqiang Kong ◽  
Fei Xiao
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Alginic Acid ◽  
Spray Coating ◽  
Polymer Binder ◽  
Silver Nanowire ◽  
Biocompatible Polymer ◽  
One Step ◽  
Nanowire Networks

A high-performance AgNW composite film was fabricated using a complex of alginic acid and poly(dopamine) as a binder via a simple and fast one-step spray coating technique at room temperature.

scholarly journals One-Step Preparation of Chitosan-Based Magnetic Adsorbent and Its Application to the Adsorption of Inorganic Arsenic in Water

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1785
Author(s):  
Zhe Jiang ◽  
Nian Li ◽  
Pei-Ying Li ◽  
Bo Liu ◽  
Hua-Jie Lai ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Thermo Gravimetric Analysis ◽  
Arsenic Concentration ◽  
Inorganic Arsenic ◽  
Batch Adsorption ◽  
Gravimetric Analysis ◽  
Order Kinetic ◽  
Magnetic Adsorbent ◽  
Adsorption Model ◽  
One Step

Chitosan is a kind of biodegradable natural polysaccharide, and it is a very promising adsorber material for removing metal ions from aqueous solutions. In this study, chitosan-based magnetic adsorbent CMC@Fe3O4 was synthesized by a one-step method using carboxymethyl chitosan (CMC) and ferric salts under relatively mild conditions. The Fe3O4 microspheres were formed and the core–shell structure of CMC@Fe3O4 was synthesized in the meantime, which was well characterized via SEM/TEM, XRD, VSM, FT-IR, thermo gravimetric analysis (TGA), XPS, size distribution, and zeta potential. The effects of initial arsenic concentration, pH, temperature, contact time, and ionic strength on adsorption quantity of inorganic arsenic was studied through batch adsorption experiments. The magnetic adsorbent CMC@Fe3O4 displayed satisfactory adsorption performance for arsenic in water samples, up to 20.1 mg/g. The optimal conditions of the adsorption process were pH 3.0, 30−50 °C, and a reaction time of 15 min. The adsorption process can be well described by pseudo-second-order kinetic model, suggesting that chemisorption was main rate-controlling step. The Langmuir adsorption model provided much higher correlation coefficient than that of Freundlich adsorption model, indicating that the adsorption behavior is monolayer adsorption on the surface of the magnetic adsorbents. The above results have demonstrated that chitosan-based magnetic adsorbent CMC@Fe3O4 is suitable for the removal of inorganic arsenic in water.

scholarly journals Evaluation of Commercial Humic Substances and Other Organic Amendments for the Immobilization of Copper Through 13C CPMAS NMR, FT-IR, and DSC Analyses

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 762 ◽  
Author(s):  
Begoña Mayans ◽  
Javier Pérez-Esteban ◽  
Consuelo Escolástico ◽  
Enrique Eymar ◽  
Alberto Masaguer
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Organic Amendments ◽  
Soil Conditions ◽  
Batch Adsorption ◽  
13C Cpmas Nmr ◽  
Term Stability ◽  
Long Term Stability ◽  
Ft Ir

The application of organic amendments to contaminated agricultural lands can immobilize metals and improve soil conditions. The chemical structures and long-term stability of commercial humic substances and other composted organic amendments (sheep and horse manure, vermicompost, pine bark, and pruning waste) were analyzed using 13C CPMAS NMR, FT-IR, and DSC to evaluate their use in soil remediation. The interactions of humic substances and manure with Cu (0 and 5000 mg kg−1) at different pH (2.5 and 5.0) were studied through a batch adsorption experiment observing the changes in their molecular structure using spectroscopic techniques. Humic substances exhibited high aromaticity and phenolic and carboxylic group content, with great affinity for Cu complexation. Humic substances and pruning waste were the most stable due to their high recalcitrant organic matter contents, whereas manure was the least stable, given the labile nature of its organic matter content. There were considerable changes in the carboxylic and phenolic groups of humic substances with pH, and also with Cu, albeit in a lesser extent, especially at pH 5.0, suggesting the great sorption capacity of humic substances and the key role of pH and these functional groups in metal complexation. Manure did not exhibit such changes. Commercial humic substances could be useful amendments for the remediation of contaminated agricultural soils due to their high sorption capacities and long-term stability.

scholarly journals Long-term stabilization of DNA at room temperature using a one-step microwave assisted process

2021 ◽  
Author(s):  
Claudia W. Narvaez Villarrubia ◽  
Keyla C. Tumas ◽  
Rajat Chauhan ◽  
Thomas MacDonald ◽  
Andrew M. Dattelbaum ◽  
...  
Keyword(s):  
Room Temperature ◽  
Microwave Assisted ◽  
One Step

scholarly journals Efficient Removal of Pb(II) from Aqueous Solutions by Using Oil Palm Bio-Waste/MWCNTs Reinforced PVA Hydrogel Composites: Kinetic, Isotherm and Thermodynamic Modeling

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 430 ◽  
Author(s):  
Muhammad Zulfiqar ◽  
San Yi Lee ◽  
Amira Azreena Mafize ◽  
Nur Adlin Mastura Abdul Kahar ◽  
Khairiraihanna Johari ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Oil Palm ◽  
Adsorption Process ◽  
In Situ Polymerization ◽  
Physical Adsorption ◽  
Crosslinking Agent ◽  
Bet Surface Area ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Pva Hydrogel

Polyvinyl alcohol (PVA) hydrogel are still restricted for some applications because their lower mechanical strength and thermal stability. The PVA-based composites are drawing attention for the removal of heavy metals based on their specific functionality in adsorption process. The main objective of this work is to synthesize oil palm bio-waste (OPB)/multiwalled carbon nanotubes (MWCNTs) reinforced PVA hydrogels in the presence of N,N′-methylenebisacrylamide (NMBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator via simple in-situ polymerization technique. The as-prepared reinforced nanocomposites were characterized by FESEM, BET surface area, differential scanning calorimetry (DSC), TGA and FTIR analysis. The possible influence of OPB and MWCNTs on the tensile strength, elongation at break and elastic modulus of the samples were investigated. It was found that reinforced nanocomposites exhibited enhanced mechanical properties as compared to non-reinforced material. The evaluation of reinforced nanocomposites was tested by the removal of Pb(II) aqueous solutions in a batch adsorption system. The pseudo-second-order kinetic model was used to illustrate the adsorption kinetic results and Langmuir isotherm was more suitable to fit the equilibrium results providing maximum adsorption capacities. The evaluation of thermodynamic parameters describes the spontaneous, endothermic and chemisorption adsorption process while activation energy reveals the physical adsorption mechanism. Therefore, the coordination effects among OPB, MWCNTs and PVA polymer hydrogels can produce a promising adsorbent material for wastewater treatment applications.

Continuous Positive Airway Pressure (CPAP) Therapy for the Treatment of Hypernasality: A Single Case Study

2014 ◽  
Vol 24 (2) ◽  
pp. 48-58 ◽  
Author(s):  
Lakshmi Kollara ◽  
Graham Schenck ◽  
Jamie Perry
Keyword(s):  
Continuous Positive Airway Pressure ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Single Case ◽  
Treatment Method ◽  
Post Treatment ◽  
Subjective Perception ◽  
Cpap Therapy ◽  
Long Term Follow Up

Studies have investigated the applications of Continuous Positive Airway Pressure (CPAP) therapy in the treatment of hypernasality due to velopharyngeal dysfunction (VPD; Cahill et al., 2004; Kuehn, 1991; Kuehn, Moon, & Folkins, 1993; Kuehn et al., 2002). The purpose of this study was to examine the effectiveness of CPAP therapy to reduce hypernasality in a female subject, post-traumatic brain injury (TBI) and pharyngeal flap, who presented with signs of VPD including persistent hypernasality. Improvements in mean velopharyngeal orifice size, subjective perception of hypernasality, and overall intelligibility were observed from the baseline to 8-week post-treatment assessment intervals. Additional long-term assessments completed at 2, 3, and 4 months post-treatment indicated decreases in immediate post-treatment improvements. Results from the present study suggest that CPAP is a safe, non-invasive, and relatively conservative treatment method for reduction of hypernasality in selected patients with TBI. More stringent long-term follow up may indicate the need for repeated CPAP treatment to maintain results.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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