Electrodialytic （ED） recovery of citric acid （CA） in the presence/absence of strong electrolytes （NaCl, CaCl2 and Feel3） was separately analyzed under different process conditions. Recovery effectiveness was qua...Electrodialytic （ED） recovery of citric acid （CA） in the presence/absence of strong electrolytes （NaCl, CaCl2 and Feel3） was separately analyzed under different process conditions. Recovery effectiveness was quantitatively estimated from current efficiency values. Efficiency attained optimum value with both flow rate and potential applied, while a monotonic rise was noted with temperature which got lowered beyond 0.1 tool. L 1 feed concentration. 40% drop in efficiency was recorded in the presence of strong electrolytes （Noel, CaCl2 and Feel3） in feed relative to their presence in concentrate. Severe transport hindrance and efficiency loss were attributed to adsorption and allied physicochemical changes occurred with anion/cation exchange membranes （AEM/CEM） and these were confirmed through contact angle/Chronopotentiometry/AFM/EDX. Sluggish potential rise （Galvanostatic mode） in Chronopotentiometric analysis indicated diffusion limiting transport of organic acids influenced AEM resistance. XRD and EDX analysis indicated the presence of salt hydrates/ions （Ca2＋/Fe3＋） over CEM justifying the resistance buildup due to adsorption of multivalent metal ion（s） and salts.展开更多
Water stable mixed-matrix membranes(MMMs) were developed to help control the global warming by capturing and sequestrating carbon dioxide(CO_2) from post-combustion flue gas originated from burning of fossil fuels.MMM...Water stable mixed-matrix membranes(MMMs) were developed to help control the global warming by capturing and sequestrating carbon dioxide(CO_2) from post-combustion flue gas originated from burning of fossil fuels.MMMs of different compositions were prepared by doping glassy polymer Ultrason? S 6010(US) with nanocrystals of zeolitic imidazolate frameworks(ZIF-300) in varying degrees. Solution-casting technique was used to fabricate various MMMs to optimize their CO_2 capturing performance from both dry and wet gases. The prepared composite membranes indicated enhanced filler-polymer interfacial adhesion, consistent distribution of nanofiller, and thermally established matrix configuration. CO_2 permeability of the membranes was enhanced as demonstrated by gas sorption and permeation experiments performed under both dry and wet conditions. As compared to neat Ultrason? membrane, CO_2 permeability of the composite membrane doped with 40 wt% ZIF-300 nanocrystals was increased by four times without disturbing CO_2/N_2 ideal selectivity. In contrast to majority of previously reported membranes, key features of the fabricated MMMs include their structural stability under humid conditions coupled with better and unaffected gas separation performance.展开更多
This paper analyzes the impact of source（ts） and drain（td） contact thicknesses on top contact（TC） and bottom contact（BC） organic thin film transistors（OTFTs） with a gate in the bottom, using a benchmarked in...This paper analyzes the impact of source（ts） and drain（td） contact thicknesses on top contact（TC） and bottom contact（BC） organic thin film transistors（OTFTs） with a gate in the bottom, using a benchmarked industry standard Atlas 2-D numerical device simulator. The parameters including drive current（Ids）, mobility（μ）, threshold voltage（Vt）and current on-off ratio（ION/IOFF） are analyzed from the device physics point of view on different electrode thicknesses, ranging from infinitesimal to 50 nm, for both top and bottom contact structures. Observations demonstrate that the performance of the BC structure is more affected by scaling of ts=din comparison to its counterpart. In the linear region, the mobility is almost constant at all the values of ts=dfor both structures. However,an increment of 18% and 83% in saturation region mobility is found for TC andBC structures, respectively with scaling down ts=dfrom 50–0 nm. Besides this, the current on-off ratio increases more sharply in the BC structure.This analysis simplifies a number of issues related to the design and fabrication of organic material based devices and circuits.展开更多
Arsenic contamination of water and soil affects many regions worldwide,and an eco-friendly and sustainable decontamination solution is needed.A promising approach involves preparing a composite adsorbent using biochar...Arsenic contamination of water and soil affects many regions worldwide,and an eco-friendly and sustainable decontamination solution is needed.A promising approach involves preparing a composite adsorbent using biochar and laterite-based adsorbent.The biochar composite(LBC)uses biochar as a stable carbon matrix that distributes treated laterite minerals efficiently and reduces agglomeration.In contrast,treated laterite,rich in mixed metal oxides like iron and aluminum hydroxides,enhances the adsorption capacity,selectivity,and stability of biochar.Process optimization determines the optimal pyrolysis temperature,organic-inorganic content,treatment methodology,biochar incorporation at a particular pH,and colloidal instability.The Langmuir isotherm model estimates maximum arsenic adsorption capacities of 21 g kg^(−1)for As(V)and 14 g kg^(−1)for As(III),respectively,with high adsorption rates at both low and high arsenic concentrations.FTIR and XPS analysis suggest hydroxyl and metal oxide aid adsorption,while the quenching experiments with EPR analysis confirm the active role of hydroxyl-free radicles in the oxidation and subsequent adsorption of arsenic species.The used adsorbent can be regenerated using 0.2 M NaOH and shows a safe landfilling option for spent adsorbent based on the TCLP tests.The synergistic combination of laterite with biochar makes LBC an efficient and sustainable solution for the removal of arsenic from water with high adsorption capacity and easy regeneration.展开更多
With enormous amounts of food being wasted at every level of consumption,the future of food security is in jeopardy.The confusion aroused due to“best before”or“use by”can be eliminated by intelligent colorimetric ...With enormous amounts of food being wasted at every level of consumption,the future of food security is in jeopardy.The confusion aroused due to“best before”or“use by”can be eliminated by intelligent colorimetric indicators which communicate the quality of food.pH indicators have gained their attention because they are simple and visually informative.Using natural pigments to fabricate pH indicators can help reducing use of carcinogenic chemicals in packaging.In this work,anthocyanins extracted from a novel flower source named Ipomoea coccinea(ICE)were added to polyvinyl alcohol(PVA)and guar gum(GG)matrix in varying amounts and was applied as antioxidant and intelligent pH indicator film to monitor the freshness of chicken fillets and to visually communicate the quality of chicken.The pH indicator was characterized for halochromism,antioxidant activity,thermogravimetry,water solubility,water contact angle,surface morphology,colorimetry and X-ray diffractograms.The color change of the extract was observed from orange to red to yellow.Film with highest amount of anthocyanin extract has increased thickness of 150.5±17.86a(μm),decreased water vapor transmission rate of 4.95±0.29a(mg day1 cm^(-2))and has a crystallinity of 52.35%.Anthocyanins started to degrade at 65◦C according to thermogravimetric analysis.The film with 20%ICE showed an excellent color change in pH solutions and the highest antioxidant activity of~91%.The food study results suggested that the developed film has the potential to be employed as an active and intelligent visual indicator in poultry packaging.展开更多
基金Financial support to execute the experimental work is gratefully acknowledged to IIT Roorkee(No.IITR/SRIC/244/FIG-Sch-A)UAY Project(ICSR/UAY/2016/SN dt 04/01/2017),India
文摘Electrodialytic （ED） recovery of citric acid （CA） in the presence/absence of strong electrolytes （NaCl, CaCl2 and Feel3） was separately analyzed under different process conditions. Recovery effectiveness was quantitatively estimated from current efficiency values. Efficiency attained optimum value with both flow rate and potential applied, while a monotonic rise was noted with temperature which got lowered beyond 0.1 tool. L 1 feed concentration. 40% drop in efficiency was recorded in the presence of strong electrolytes （Noel, CaCl2 and Feel3） in feed relative to their presence in concentrate. Severe transport hindrance and efficiency loss were attributed to adsorption and allied physicochemical changes occurred with anion/cation exchange membranes （AEM/CEM） and these were confirmed through contact angle/Chronopotentiometry/AFM/EDX. Sluggish potential rise （Galvanostatic mode） in Chronopotentiometric analysis indicated diffusion limiting transport of organic acids influenced AEM resistance. XRD and EDX analysis indicated the presence of salt hydrates/ions （Ca2＋/Fe3＋） over CEM justifying the resistance buildup due to adsorption of multivalent metal ion（s） and salts.
基金KACST-Technology Innovation Center on Carbon Capture and Sequestration(CCS),King Fahd University of Petroleum and Minerals,Dhahran,Kingdom of Saudi Arabia(KSA)for providing support for this work
文摘Water stable mixed-matrix membranes(MMMs) were developed to help control the global warming by capturing and sequestrating carbon dioxide(CO_2) from post-combustion flue gas originated from burning of fossil fuels.MMMs of different compositions were prepared by doping glassy polymer Ultrason? S 6010(US) with nanocrystals of zeolitic imidazolate frameworks(ZIF-300) in varying degrees. Solution-casting technique was used to fabricate various MMMs to optimize their CO_2 capturing performance from both dry and wet gases. The prepared composite membranes indicated enhanced filler-polymer interfacial adhesion, consistent distribution of nanofiller, and thermally established matrix configuration. CO_2 permeability of the membranes was enhanced as demonstrated by gas sorption and permeation experiments performed under both dry and wet conditions. As compared to neat Ultrason? membrane, CO_2 permeability of the composite membrane doped with 40 wt% ZIF-300 nanocrystals was increased by four times without disturbing CO_2/N_2 ideal selectivity. In contrast to majority of previously reported membranes, key features of the fabricated MMMs include their structural stability under humid conditions coupled with better and unaffected gas separation performance.
文摘This paper analyzes the impact of source（ts） and drain（td） contact thicknesses on top contact（TC） and bottom contact（BC） organic thin film transistors（OTFTs） with a gate in the bottom, using a benchmarked industry standard Atlas 2-D numerical device simulator. The parameters including drive current（Ids）, mobility（μ）, threshold voltage（Vt）and current on-off ratio（ION/IOFF） are analyzed from the device physics point of view on different electrode thicknesses, ranging from infinitesimal to 50 nm, for both top and bottom contact structures. Observations demonstrate that the performance of the BC structure is more affected by scaling of ts=din comparison to its counterpart. In the linear region, the mobility is almost constant at all the values of ts=dfor both structures. However,an increment of 18% and 83% in saturation region mobility is found for TC andBC structures, respectively with scaling down ts=dfrom 50–0 nm. Besides this, the current on-off ratio increases more sharply in the BC structure.This analysis simplifies a number of issues related to the design and fabrication of organic material based devices and circuits.
文摘Arsenic contamination of water and soil affects many regions worldwide,and an eco-friendly and sustainable decontamination solution is needed.A promising approach involves preparing a composite adsorbent using biochar and laterite-based adsorbent.The biochar composite(LBC)uses biochar as a stable carbon matrix that distributes treated laterite minerals efficiently and reduces agglomeration.In contrast,treated laterite,rich in mixed metal oxides like iron and aluminum hydroxides,enhances the adsorption capacity,selectivity,and stability of biochar.Process optimization determines the optimal pyrolysis temperature,organic-inorganic content,treatment methodology,biochar incorporation at a particular pH,and colloidal instability.The Langmuir isotherm model estimates maximum arsenic adsorption capacities of 21 g kg^(−1)for As(V)and 14 g kg^(−1)for As(III),respectively,with high adsorption rates at both low and high arsenic concentrations.FTIR and XPS analysis suggest hydroxyl and metal oxide aid adsorption,while the quenching experiments with EPR analysis confirm the active role of hydroxyl-free radicles in the oxidation and subsequent adsorption of arsenic species.The used adsorbent can be regenerated using 0.2 M NaOH and shows a safe landfilling option for spent adsorbent based on the TCLP tests.The synergistic combination of laterite with biochar makes LBC an efficient and sustainable solution for the removal of arsenic from water with high adsorption capacity and easy regeneration.
文摘With enormous amounts of food being wasted at every level of consumption,the future of food security is in jeopardy.The confusion aroused due to“best before”or“use by”can be eliminated by intelligent colorimetric indicators which communicate the quality of food.pH indicators have gained their attention because they are simple and visually informative.Using natural pigments to fabricate pH indicators can help reducing use of carcinogenic chemicals in packaging.In this work,anthocyanins extracted from a novel flower source named Ipomoea coccinea(ICE)were added to polyvinyl alcohol(PVA)and guar gum(GG)matrix in varying amounts and was applied as antioxidant and intelligent pH indicator film to monitor the freshness of chicken fillets and to visually communicate the quality of chicken.The pH indicator was characterized for halochromism,antioxidant activity,thermogravimetry,water solubility,water contact angle,surface morphology,colorimetry and X-ray diffractograms.The color change of the extract was observed from orange to red to yellow.Film with highest amount of anthocyanin extract has increased thickness of 150.5±17.86a(μm),decreased water vapor transmission rate of 4.95±0.29a(mg day1 cm^(-2))and has a crystallinity of 52.35%.Anthocyanins started to degrade at 65◦C according to thermogravimetric analysis.The film with 20%ICE showed an excellent color change in pH solutions and the highest antioxidant activity of~91%.The food study results suggested that the developed film has the potential to be employed as an active and intelligent visual indicator in poultry packaging.
