Abstract
The adsorption of Fe (III) metal ions in water media using the ionic imprinted polymer has been carried out with a polyeugenol base polymer and poly(ethylene glycol) diglycidyl ether (PEGDE) ...as the crosslinking agent. The adsorbent is in the form of Ionic Imprinted Polymer Fe (IIP-Fe), and Non-Imprinted Polymer (NIP) was also used as a comparison. The polymer results are characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), and Fourier Transform Infrared (FTIR). The adsorption test was performed to obtain the adsorption kinetics by varying the contact time. Meanwhile, adsorption isotherm was performed by varying the concentration of adsorbate, and adsorption selectivity between binary metal ions of Fe(III)/Cr(III), F(III)/Zn(II), and Fe(III)/Ag(I). Also, the adsorption mechanism was studied using different solvents such as HCl, Aquadest, KNO
3
, and Na
2
EDTA. The results of the filtrate in the adsorption test were characterized using AAS. The results showed the optimum time in kinetics was 60 minutes, the adsorption isotherm followed the Langmuir model with a large adsorption capacity of 23.640 mg/g on IIP-Fe and 17.636 mg/g on NIP. Adsorption selectivity towards Fe (III) metal ions in binary metal ions shows results in the order of Fe(III)/Zn(II)>Fe(III)/Cr(II)>Fe(III)/Ag(I), while the adsorption mechanism was dominated by hydrogen bonds.
Abstract
Ionic Imprinted Polymer (IIP) with polyeugenoxy acetate (PA) as the base polymer, EGDMA as the crosslinking agent, and AIBN as the initiator have been synthesized to adsorb Fe(III) metal ...ions. NIP (non-imprinted polymer) was used as a comparison for this study. The produced polymer was characterized using FTIR spectroscopy and SEM-EDX. Adsorption rate and capacity were examined through adsorption isotherm and kinetics studies for all adsorbents. The adsorption selectivity test was done with mixed-metal solutions of Zn(II), Cu(II), Cd(II), and Ag(I). The results of SEM analysis on IIP-PA show a more uniform and regular size than NIP-PA. Adsorption of Fe(III) in IIP-PA and NIP-PA follows pseudo-second-order kinetics, and the adsorption isotherm both follow the Langmuir theory. The adsorption capacity of Fe(III) metal ions in IIP-PA is 10.88 mg/g, and the adsorption capacity of NIP-PA is 7.94 mg/g. The mechanism of adsorption of Fe(III) metal ions in IIP-PA and NIP-PA was dominated by hydrogen bonds between the -COOH groups and Fe(III). In binary solutions, IIP-PA adsorption selectivity coefficient is higher than NIP-PA with the order of Fe(III)/Zn (II)>Fe(III)/Cu(II)>Fe(III)/Cd(II)>Fe(III)/Ag(I)
The use of some base metal oxide already widely studied for having beneficial properties in CO oxidation catalytic system. The properties of these base metals such as lower working temperature, high ...CO affinity, and economically cheaper would be beneficial for this solid system catalyst. The study of various base metal oxides shown these kinds of characteristics, but there still a few analyses of comparison among the various base oxide metals used as the support system for the oxidation reaction catalytic system. This study would give a comparison in the difference of the adsorption energy of various base oxide metals. This adsorption energy is one factor that promoting the activity of the catalytic system due to its affinity to the reactant on their surfaces. The DFT ab initio calculation for this comparison shows that NiO is the base metal oxide that having the highest CO adsorption energy. This oxide could be a potential support system combined with potential solid oxidative catalytic system.
Household air pollution from burning biomass fuel is increasingly recognised as a major global health concern. Biomass smoke is associated with chronic obstructive pulmonary disease (COPD) in Asian ...and Central American countries, but there are few data from Africa.
We hypothesised that reported wood smoke as compared to charcoal smoke exposure would be associated with a reduction in forced expiratory volume in 1 second in Malawian adults. Volunteers from urban and rural locations performed spirometry and completed a questionnaire assessing lifestyle, including smoke exposure and symptoms.
In total, 374 adults were recruited; 61% were female; 160 cooked using charcoal and 174 used wood. Individuals who used wood as their main domestic fuel had significantly worse lung function than those who used charcoal. Significant factors associated with impaired lung function in the multivariate model were age, sex, height, wood smoke exposure, poverty, smoking and previous tuberculosis.
Our data suggest that wood smoke and poverty contribute to reduced lung function in rural Africans and that COPD is common in this population. The use of charcoal in rural populations may be relatively protective, and this idea merits further study. The risk factors for impaired lung function in Malawi are multiple and require more detailed characterisation to plan appropriate health interventions.
Background:Air pollution from biomass fuels in Africa is a significant cause of mortality and morbidity both in adults and children. The work describes the nature and quantity of smoke exposure from ...biomass fuel in Malawian homes.Methods:Markers of indoor air quality were measured in 62 homes (31 rural and 31 urban) over a typical 24 h period. Four different devices were used (one gravimetric device, two photometric devices and a carbon monoxide (HOBO) monitor. Gravimetric samples were analysed for transition metal content. Data on cooking and lighting fuel type together with information on indicators of socioeconomic status were collected by questionnaire.Results:Respirable dust levels in both the urban and rural environment were high with the mean (SD) 24 h average levels being 226 μg/m3 (206 μg/m3). Data from real-time instruments indicated respirable dust concentrations were >250 μg/m3 for >1 h per day in 52% of rural homes and 17% of urban homes. Average carbon monoxide levels were significantly higher in urban compared with rural homes (6.14 ppm vs 1.87 ppm; p<0.001). The transition metal content of the smoke was low, with no significant difference found between urban and rural homes.Conclusions:Indoor air pollution levels in Malawian homes are high. Further investigation is justified because the levels that we have demonstrated are hazardous and are likely to be damaging to health. Interventions should be sought to reduce exposure to concentrations less harmful to health.
Abstract
The aim of this study is to show specification error in a model that exclude a relevant independent variable. Literature suggests that human capital features, such as education, must be ...considered in studies of social problems, such as environmental degradation. Therefore, the absence of education variable in a multiple regression equation model that explain the determinants of environmental degradation may result in model misspecification. Firstly, this study constructs a model with four variables, i.e.: unemployment level (ULEVEL), poor areas (POOR_AREAS), income inequality (INEQ) and access to electricity (ELEC), that may affect environmental quality in Indonesia. Secondly, this study examines the second model when education variable is included in the model. This study uses panel data regression method from 33 provinces in Indonesia during 2012 to 2018. The results of the first model show that all four control variables are statistically significant. However, ELEC’s coefficient has unexpected sign. When education variable is added to the second model, ELEC’s coefficient has expected sign. In conclusion, education variable is theoretically and empirically important variable to explain the changes in the quality of environment in Indonesia and education variable should be used in the model to avoid specification error in a model.
Synthesis of silica-alumina mesoporous with the material based on Lapindo mud by template gelatin from catfish bones using the sol-gel method has been performed. Lapindo mud contains Al and Si as ...much as 48.8 and 22.6 % so can be leached. The leaching by HCl 6 M and NaOH 6M obtained dissolved Al and Si were 30,938 and 62,300 mg L1 . The gelatin from catfish bones has typed with a molecular weight of 100 kDa. The Mesoporous Si-Al showed that calcination at a temperature of 500C gave the best porosity with surface area, volume, and pore diameter of 133.076 m2g -1, 0.564 cc g-1, and 9.00 nm, respectively. The amorphous Si-Al character showed at 500C calcination, but at 600 and 700C crystals formed from alumina. TEM image showed mesoporous silica-alumina at 500C a wormhole pore was formed, while at temperatures 600 and 700C, there was a decrease in the number of pores so that the surface area of the material becomes small.
In the present work, immobilization of humic acid on bentonite and its application as an adsorbent of Cs137 (Cesium) and Am241 (Americium) is performed. The parameters studied are rate constant, ...adsorption capacity, and adsorption energy. This research started with the immobilization of humic acid on a bentonite surface followed by a stability test for immobilization of humic acid at various acidities. Adsorption of Cs 137 and AM 241 ions was conducted by first examining the optimum pH giving minimum complexed ions by the soluble fraction of humic acid and maximum adsorbed ions on the adsorbent. While adsorption energy and capacity were determined by the Langmuir isotherm adsorption model. The result shows that the amount of immobilization of humic acid on bentonite is 39.75 % (w/w) at optimum conditions. Immobilization of humic acid was stable up to pH 12.0. For both ions, optimum adsorption occurred at pH 5. At this optimum condition, the adsorption energies of 21.481 kJ.mol-1 and 22.276 kJ.mol-1 for Cs173 and Am241 are obtained, respectively. The result also shows that adsorption capacity and energy for Am241 were higher than that for Cs137 which indicates the affinity of Am241 for both adsorbents was higher than that of Cs137.
This paper focuses on the simulation of Beyond Visual Range (BVR) Air Combat using calculation of Probability of Kill (PK) and Supremacy to analyze the effectivity of the tactics and strategies. The ...developed simulation program is expected to be used as a means of developing tactics, weapons systems evaluation and to support other air combat system applications. The simulation system can be utilized so that strategy for using weapons and better tactics for maneuver can be determined and formulated in the face of an aerial battle. The simulation illustrates how an aerial battle in a 2D plane took place. The battle occurs between two sides and can also cover case of many against many air battle. Fighters maneuver will be generated based on logic and defined tactic by providing input in the form of initial conditions. Formulation / functions, parameters and variables influencing the fighter effectiveness will be taken into account. These elements are modelled using a dynamic and open scenario approach. The simulation used a method called 'Missile Launch Envelope Model' for computing PK of missile along its way to the target. Simulation results for one versus one and many versus many cases show that the developed system can produce good and relatively realistic prediction of the outcome. Further modification of simulation program include fly out modeling to the missile.
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