Design, simulation and characterization of a MEMS inertia switch with flexible CNTs/Cu composite array layer between electrodes for prolonging contact time

2015 ◽  
Vol 25 (8) ◽  
pp. 085012 ◽  
Author(s):  
Yang Wang ◽  
Zhuoqing Yang ◽  
Qiu Xu ◽  
Wenguo Chen ◽  
Guifu Ding ◽  
...  
Keyword(s):  
Contact Time

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

scholarly journals PHYSICAL CHARACTERIZATION OF IN SITU OPHTHALMIC GEL: A CONCISE REVIEW

2022 ◽  
pp. 18-21
Author(s):  
INSAN SUNAN KURNIAWANSYAH ◽  
IYAN SOPYAN ◽  
GENI REFSI
Keyword(s):  
Therapeutic Effect ◽  
Contact Time ◽  
Drug Preparation ◽  
Journal Review ◽  
In Situ Gel ◽  
Concise Review ◽  
Gel Formulations ◽  
Active Substances

In situ ophthalmic gel is a type of eye drug preparation that has a higher bioavailability value and has a longer contact time with maximum therapeutic effect and with minimal side effects compared to conventional eye preparations. The preparation of ophthalmic in situ gel is required characterization to make sure that the prepared preparations meet the standards and are safe when used. This journal review aims to look at the methods used in characterizing physical properties in in situ ophthalmic gel formulations with different active substances such as rheology studies, organoleptic tests, pH, clarity, and gelling capacity. In order to get the best formulation of in situ ophthalmic gel preparations so as to provide maximum therapeutic effect.

scholarly journals A Adsorbent of Chitosan Linked by Methylene Bridge and Schiff Base of 4,4-diaminodiphenyl Ether –vanillin : Synthesis, Characterization and Its Application After Reacted by Zn(II) Ion as Antibacterial Agent

2018 ◽  
Vol 3 (4) ◽  
pp. 173
Author(s):  
Ahmad Fatoni ◽  
Poedji Loekitowati Hariani ◽  
Hermansyah Hermansyah ◽  
Aldes Lesbani
Keyword(s):  
Schiff Base ◽  
Antibacterial Agent ◽  
Contact Time ◽  
Room Temperature ◽  
Solution Ph ◽  
Methylene Bridge ◽  
Modified Chitosan ◽  
Paper Disk ◽  
Disk Method

The synthesis chitosan linked by methylene bridge-Schiff base of 4,4-diaminodiphenyl ether-vanillin (modified chitosan adsorbent) has been studied. The aims of this research were modification of chitosan with Schiff base of 4,4-diaminodiphenyl ether-vanillin and formaldehyde and its application as antibacterial agent after used as an adsorbent of Zn(II) ion. Characterization of modified chitosan adsorbent was conducted using FTIR spectroscopy. Process of adsorption were conducted at  0.15 g of modified chitosan adsorbent reacted by concentration of Zn(II) ion solution (pH 6, 150 mg/L, 50 mL), contact time at 150 min. and  at room temperature (280C). Modified chitosan adsorbent after reacted by Zn(II) ion solution as antibacterial agent with paper disk method. The result showed that chitosan can be modified with Schiff base of 4,4-diaminodiphenyl ether-vanillin and formaldehyde to form chitosan linked methylene bridge and Schiff base of 4,4-diaminodiphenyl ether-vanillin. Antibacterial of chitosan and modified chitosan adsorbent were higher than modified chitosan adsorbent after reacted by Zn(II) ion. Keywords : modified chitosan, antibacterial agent

scholarly journals Synthesis and Characterization of Piperidin-4-one Derivatives Using Green Solvent

2020 ◽  
Vol 32 (4) ◽  
pp. 727-732
Author(s):  
Harish Sharma ◽  
Rajesh Kumar ◽  
Mahesh Chandra Vishwakarma ◽  
Sushil Kumar Joshi ◽  
Narender Singh Bhandari
Keyword(s):  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Green Solvent ◽  
Optimum Ph ◽  
Influence Of Ph ◽  
Biosorption Equilibrium

In present study, Pyras pashia leaves were used as low cost biosorbent to study biosorption of Cu(II), Pb(II) and Cd(II) ions from contaminated wastewater. In the employed batch methods pH, contact time, metal ion concentration, temperature, biosorbent doses were taken as study parameters. The pH was varied from pH 1-9 to study the influence of pH on biosorption of metal ions by Pyras pashia. The optimum pH for the removal of Cu(II), Pb(II) and Cd(II) is observed at pH 5. The biosorption equilibrium time was varied between 15-75 min. Langmuir, Freundlich and Temkin isotherms were employed to study the biosorption. The biosorption parameter fits well with Langmuir isotherm. The biosorption of metal ions was increased with increasing biosorbent dose and contact time while increase in pH, metal ion concentration and temperature decrease the biosorption. Thermodynamic data suggest that the bisorption process was spontaneous, feasible and endothermic.

scholarly journals Biosorption of Pb(II) by Bacillus badius AK strain originating from rotary drum compost of water hyacinth

2016 ◽  
Vol 75 (5) ◽  
pp. 1071-1083 ◽  
Author(s):  
Isha Vishan ◽  
Avishek Laha ◽  
Ajay Kalamdhad
Keyword(s):  
Water Hyacinth ◽  
Contact Time ◽  
Bacterial Biomass ◽  
Initial Ph ◽  
Rate Kinetics ◽  
Pseudo Second Order ◽  
Rotary Drum ◽  
Bacterium Bacillus ◽  
Biomass Dosage

The presence of heavy metals in the environment due to industrial activities is of serious concern because of their toxic behaviour towards humans and other forms of life. Biosorption of Pb(II) using dry bacterial biomass of Bacillus badius AK, previously isolated from water hyacinth compost, has been undertaken in batch system. The optimum conditions of biosorption were determined by investigating the initial pH, contact time, initial biomass dosage at constant temperature of 40 °C, initial metal concentration of 100 mg/L and rotational speed of 150 rpm. The optimum pH was found to be 5 and equilibrium contact time was 2.5 h. The maximum biosorption capacity of Pb(II) on Bacillus badius AK was 138.8 mg/g at an initial concentration of 100 mg/L. A kinetics study revealed that the adsorption process followed pseudo second order rate kinetics. The experimental data were fitted to the Langmuir isotherm. Characterization of the biomass indicated the presence of several functional groups. The results indicated that the bacterium Bacillus badius AK is efficient for the removal of Pb(II).

scholarly journals Synthesis and Characterization of a Dual-Cation Organomontmorillonite Nanocomposite

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2320 ◽  
Author(s):  
Guifang Wang ◽  
Huizhen Xiao ◽  
Shuai Zhang ◽  
Jun Qiu ◽  
Hengjun Li ◽  
...  
Keyword(s):  
Contact Time ◽  
Molecular Volume ◽  
Cetyltrimethylammonium Chloride ◽  
Organic Modifiers ◽  
X Ray Diffraction ◽  
Interlayer Region ◽  
Pseudo Second Order ◽  
Adsorption Amount ◽  
Xrd Patterns

In this study, a novel dual-cation organomontmorillonites (OMt) nanocomposite was synthesized by two kinds of modifiers cetyltrimethylammonium chloride and cysteamine hydrochloride, and the adsorption behavior of modifiers into montmorillonite (Mt) has been investigated. The OMt were characterized by techniques, such as X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and thermogravimetric and differential thermal (TG-DTA) analyses. The effects of temperature, contact time, the order of addition and the concentration of organic modifiers on the amounts of organics adsorbed were investigated. The adsorption amount of cetyltrimethylammonium chloride (CTAC) and cysteamine hydrochloride (CSH) increased with the increase of the added CTAC amount and contact time, while the addition order of modifiers and modification temperature had no significant effect on the actual adsorption amount of CTAC and CSH on Mt, as confirmed by the XRD patterns. The experimentally determined isotherms showed a good fit with the Langmuir adsorption models. The adsorption kinetics demonstrated that the adsorption of CTAC and CSH by Mt followed the pseudo-second-order model, and CTAC adsorption rate on Mt was faster than that of CSH. FTIR spectrum clearly revealed the incorporation of surfactant ions into the interlayer region. The TG-DTA analyses showed that the total mass losses of OMt strongly depended on the molecular volume of modifiers.

scholarly journals Romanian bentonite and fly ash characterization and their use in heavy metal “in-situ” immobilization in polluted soils

2017 ◽  
Vol 18 ◽  
pp. 01022
Author(s):  
Săndica Liliana Gherghe ◽  
Ildiko Anger ◽  
Georgiana Moise ◽  
Roxana Trusca
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Fly Ash ◽  
Contact Time ◽  
In Situ Immobilization ◽  
Polluted Soils ◽  
Ft Ir ◽  
Metallurgical Activities

This article presents the characterization of the Romanian bentonite and fly ash, using different techniques: FAAS, XRD, FT-IR, SEM and EDAX and their evaluation as sorbents for heavy metals immobilization in polluted soils coming from mining and metallurgical activities. The applicability of bentonite and fly ash for Pb (II) and Zn (II) immobilization was studied using aqueous solutions of these metals. The influence of the pH and contact time were studied. The results shown that the Romanian bentonite and fly ash could be used for Pb (II) and Zn (II) immobilization in polluted soils from brownfields.

scholarly journals Sintesis dan Karakterisasi Silika Abu Ampas Tebu Termodifikasi Arginin sebagai Adsorben Ion Logam Cu(II)

2018 ◽  
Vol 14 (2) ◽  
pp. 333
Author(s):  
Candra Purnawan ◽  
Tri Martini ◽  
Ima Puspita Rini
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Sol Gel ◽  
Ftir Analysis ◽  
Batch Method ◽  
Modified Silica ◽  
Adsorption Ability ◽  
Copper Adsorption ◽  
Ability Test

<p>Telah dilakukan penelitian tentang sintesis dan karakterisasi silika dari abu ampas tebu termodifikasi arginin dengan senyawa penggandeng glisidoksipropiltrimetoksisilan (GPTMS) sebagai adsorben ion logam Cu(II). Penelitian ini bertujuan untuk mengetahui karakterisasi silika abu ampas tebu termodifikasi arginin dengan senyawa penggandeng GPTMS sebagai adsorben ion logam Cu(II). Sintesis silika termodifikasi arginin dengan senyawa penggandeng GPTMS dilakukan dengan metode sol-gel. Adsorben tersebut dikarakterisasi dengan XRD, FTIR dan SAA. Uji kemampuan adsorpsi dilakukan menggunakan metode batch dengan larutan ion logam Cu(II), variasi pH, waktu kontak dan konsentrasi. Hasil penelitian menunjukkan perubahan difraktogram XRD pada silika termodifikasi dan silika abu ampas tebu (silika AAT). Difraktogram menunjukkan puncak melebar pada 2θ sebesar 10-15° dan 20-25°. Analisis FTIR menunjukkan Serapan baru –CH, ̶ NH tekuk, ̶ CN berturut-turut pada daerah 2947, 1570, dan 1356 cm<sup>-1</sup>. Analisis SAA menunjukkan peningkatan luas permukaan pada silika termodifikasi arginin daripada silika dari 64,31 m<sup>2</sup>/g menjadi 382,67 m<sup>2</sup>/g. Kondisi terbaik adsorpsi ion logam Cu(II) dengan adsorben silika termodifikasi arginin terjadi pada pH 6 dengan waktu kontak 45 menit. Silika termodifikasi arginin mengalami peningkatan kapasitas adsorpsi dibandingkan silika dengan kapasitas adsorpsi yaitu dari 0,12 mg/g menjadi 0,52 mg/g. Isoterm adsorpsi ion logam Cu(II) lebih dominan mengikuti isoterm Langmuir dengan r = 0,997.</p><p><strong>Synthesis </strong><strong>a</strong><strong>nd Characterization </strong><strong>o</strong><strong>f Arginine-Modified Silica </strong><strong>f</strong><strong>rom Baggase Ash </strong><strong>a</strong><strong>s C</strong><strong>u</strong><strong>(I</strong><strong>I</strong><strong>) Ions Adsorbent</strong><strong>.</strong> The synthesis and characterization of arginine modified silica from bagasse ash with crosslinker glycydoxypropyltrimethoxyxylane (GPTMS) as an adsorbent for Cu (II) ions has been studied. This research aimed to determine the characterization of arginine modified silica with crosslinker GPTMS as an adsorbent for Cu(II) ions. Synthesis arginine modified silica with crosslinker GPTMS was conducted using sol-gel method. The adsorbent was characterized by XRD, FTIR and SAA. Adsorption ability test conducted using the batch method with a solution of Cu(II) ions, variation of pH, contact time and concentration. The results showed the change in the XRD diffractogram of arginine modified silica from bagasse (silica ATT). XRD diffractogram releaved broad peaks at 2θ 10-15° and 20-25°. FTIR analysis showed a new absorption -CH, -NH bending, -C-N on area of 2947, 1570, and 1356 cm<sup>-1</sup>, respectively SAA analysis showed that the arginine-modified silica with crosslinker GPTMS has higher surface area than silica from 64.31 m<sup>2</sup>/g to 382.67 m<sup>2</sup>/g. The best conditions for copper adsorption with adsorbent arginine modified silica occured at pH 6 with a contact time of 45 minutes. Arginine modified silica has higher adsorption capacity than silica with a adsorption capacity from 0.12 mg/g to 0.52 mg/g. Adsorption of Cu (II) metal ions more dominantly follows Langmuir isotherms with r = 0.997.<strong></strong></p><p> </p>

scholarly journals ADSORPTION OF PHENOL POLLUTANTS FROM AQUEOUS SOLUTION USING Ca-BENTONITE/CHITOSAN COMPOSITE

2015 ◽  
Vol 22 (2) ◽  
pp. 233 ◽  
Author(s):  
Poedji Loekitowati Hariani ◽  
Fatma Fatma ◽  
Fahma Riyanti ◽  
Hesti Ratnasari
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Contact Time ◽  
Batch Adsorption ◽  
Shrimp Waste ◽  
Initial Concentration ◽  
X Ray ◽  
Chitosan Composite ◽  
Scanning Electron

Phenolic compounds areorganic pollutants that are toxic and carcinogenic.The presence of phenol in the environmentcan be adverse to humanand the environmentalsystem. One methodthat iseffective toreduce thephenolisadsorption. In this study, the adsorption of phenol in aqueous solution using Ca-bentonite/chitosan composite was investigated. Chitosan is the deacetylation product of chitin from shrimp waste. Characterization of Ca-bentonite/chitosan composite was done by using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy-Energy Dispersive X Ray Spectroscopy (SEM-EDX). Batch adsorption studies were performed to evaluate the effects of some parameters such as initial concentration of phenol, composite weight, pH and contact time. The results showed that FTIR spectra of Ca-bentonite/chitosan composite presented the characteristic of peak of Ca-bentonite and chitosan that confirmed the successful synthesis of composite. The SEM-EDX characterizationresultsshowedCa-bentonite surfacecoverage by chitosanand the presence ofcarbonandnitrogenelementsinCa-bentonite/chitosancompositeindicated that chitosan had bonded with bentonite. The optimum condition of adsorption of Ca-bentonite/chitosan to phenol was obtained at 125 mg.L-1 of concentration in which the weight of composite was 1.0 g, the pH of solution was 7, the contact time was 30 minutes, and the capacity of adsorption was 12.496 mg.g-1.

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