Relevant bibliographies by topics / Chemical ABsorbent

Academic literature on the topic 'Chemical ABsorbent'

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Published: 10 March 2023

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Journal articles on the topic "Chemical ABsorbent"

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Zilberman, P. "The CO2 Absorber Based on LiOH." Acta Medica Marisiensis 61, no. 1 (March 1, 2015): 4–6. http://dx.doi.org/10.1515/amma-2015-0023.

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AbstractCarbon dioxide absorbers have been used in anesthesiology for many years. However, this process is not limited to this field of medicine. Removing carbon dioxide from human environment is used in other areas as well: mining industry, submarines, scuba diving, space travel and many others. The rationale to remove carbon dioxide from confined spaces is that cannot be eliminated otherwise. Anesthesia practitioners are well aware of this component of the circle system, the carbon dioxide absorber. In daily practice the clinician is less concerned with what kind of substance fills the dedicated canister, as this is usually in the care of the maintenance personnel. The appearance of Sevoflurane and Desflurane, with their own chemical characteristics, prompted the clinician to dedicate new attention to these absorbents. The classical substances used for this purpose are different combinations of limes. The practical concern of the anesthesiologist is to notice when the absorbent is consumed and call for its replacement. Still, many other aspects remain: compound A formation with Sevoflurane, carbon monoxide formation with Desflurane and dry absorbent for instance. The latest member of these products in the medical field is the LiOH carbon dioxide absorbent. Although used for many years in the space exploration, its way into the operating room is a rather recent achievement. Special chemical properties and high absorptive capacity make this new type of absorbent an attractive option for modern anesthesia practice. The article below invites the reader through a short journey on the history of the CO2 absorbents and anesthesia circuits, Lithiumas a chemical element and, finally, to this new type of absorbent.
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Wardhana, Krisna Adhitya, Saepulloh Saepulloh, and Reynaldo Biantoro. "Pemanfaatan Lumpur Primer Industri Kertas sebagai Absorben." JURNAL SELULOSA 8, no. 01 (October 16, 2018): 9. http://dx.doi.org/10.25269/jsel.v1i01.220.

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The Utilization of Primary Sludge from Paper Mills as AbsorbentAbstractThe primary sludge from paper mill contains cellulose fiber that has high absorption capacity and potential to be used as an absorbent for hydrophobic compounds. The utilization of primary sludge from paper mill using raw material of waste paper and virgin pulp to be used as an absorbent has been conducted. The stages process of absorbent fabrication was consisted of three stages such as drying, mechanical and chemical processes. Mechanical process conducted were crushing and grinding methods to increase surface area and pore volume of sludge. Meanwhile silanization process as chemical treatment using solution of γ-metacryloxypropyl trimethoxysilane in ethanol to improve the hydrophobic properties of primary sludge was also done. Absorbent products were tested for the maximum sorbency, the sorbent performance, absorption of hydrophobic liquid, absorption of hydrophobic dust, and contact angle test to conduct their performance. The absorbency of absorbent product which is covered by cushion material was also tested. Result indicated that the absorption performance of some absorbent product is higher than commercial absorbent on hydrophobic liquid and hydrophobic dust absorption test. But it was lower than commercial absorbent on maximum sorbency and the sorbent performance test. The use of cushion material as a wrapper could make it easy in the collection and could increase the absorbency.Keywords: primary sludge; mechanical; silanization; absorbent; hydrophobic AbstrakLumpur primer dari industri kertas mengandung serat selulosa yang memiliki daya serap tinggi dan memiliki potensi dimanfaatkan sebagai absorben senyawa hidrofobik. Pemanfaatan lumpur primer industri kertas berbahan baku kertas bekas dan virgin pulp sebagai absorben telah dilakukan. Tahapan proses pembuatan absorben dari lumpur primer meliputi proses pengeringan, proses mekanis, dan proses kimia. Proses mekanis yang dilakukan adalah crushing dan grinding untuk meningkatkan luas permukaan dan volume pori-pori lumpur dilanjutkan dengan proses silanisasi (silanization) sebagai perlakuan kimia menggunakan larutan γ-metacryloxypropyl trimethoxysilane dalam etanol untuk meningkatkan sifat hidrofobik lumpur. Produk absorben diuji daya serap maksimum (maximum sorbency), kinerja absorben, penyerapan cairan hidrofobik, penyerapan debu hidrofobik, dan pengujian sudut kontak. Daya serap produk absorben yang ditutup bahan bahan cushion juga diuji. Hasil menunjukkan kemampuan absorbsi cairan hidrofobik dan debu hidrofobik dari beberapa perlakuan produk absorben lebih tinggi dari absorben komersial, sedangkan hasil maximum sorbency dan uji kinerja absorben menunjukkan hasil lebih rendah dari absorben komersial. Penggunaan bahan cushion sebagai pembungkus dapat memudahkan dalam pengumpulan dan dapat meningkatkan penyerapan.Kata kunci: lumpur primer; mekanis; silanisasi; absorben; hidrofobik
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Arunkumar, V., K. Krishnamurthy, C. Maheswari, B. Meenakshipriya, and R. Vinoth. "Removal of NOX from diesel engine exhaust by using different chemical absorbent in a lab-scale packed column system." Measurement and Control 52, no. 7-8 (June 24, 2019): 1095–101. http://dx.doi.org/10.1177/0020294019858167.

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Emissions of NOX from automobile causes various environmental impacts. In order to satisfy the emission norms and standards, it is necessary to reduce the toxic gases from emission. This paper concentrates on designing a packed column and analysis on the selection of an effective absorbent to reduce NOX emission from diesel engines. NOX emission is taken from the exhaust of diesel engine (Kirloskar TV1 Diesel engine). Flue gas inlet to the packed column and the treated gas at the outlet of the packed column are measured using NOX inlet and outlet gas sensors, respectively. Absorbent flow is carried out in a lab-scale packed column experimental setup. Various parameters of the packed column such as liquid: gas ratio, diameter, total height and packing height are determined based on the mathematical modeling. The NOX emission was experimentally measured with various combinations of different absorbents with different flow rate. Based on the experiments, effective absorbents are chosen as NaClO2 and NaOH. Experimental results show chemical absorbent combination with 0.5 M concentration of sodium chlorite and 0.3 M concentration of sodium hydroxide at 80% data acquisition card opening condition is absorbing NOX effectively.
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Purnawan, Irfan, Sutrasno Kartohardjono, Levana Wibowo, Annisa Faiza Ramadhani, Woei Jye Lau, and Arifina Febriasari. "Effect of Absorbents on NOx Removal through Polyvinylidene Fluoride (PVDF) Hollow Fiber Membrane Modules." International Journal of Chemical Engineering 2021 (August 16, 2021): 1–8. http://dx.doi.org/10.1155/2021/8277082.

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NOx (NO and NO2) are air toxins that endanger life and represent a hazard to the environment, such as photochemical smog, global warming, acid rain, ozone depletion, and the occurrence of respiratory infections. Some technological strategies to diminish NOx emissions to meet regulations depend on two techniques: the dry process and the wet process. This study applies polyvinylidene fluoride (PVDF) hollow fiber membrane modules as a medium to remove NOx from solutions containing several absorbents such as hydrogen peroxide and nitric acid (H2O2-HNO3) solutions, sodium chlorite and sodium hydroxide (NaClO2-NaOH) solutions, and sodium chlorate and sodium hydroxide (NaClO3-NaOH) solutions. The experimental results showed that the oxidant’s strength influences NOx removal efficiency, where the absorbent solutions containing hydrogen peroxide had the highest removal efficiency as hydrogen peroxide is the most potent oxidant, followed by sodium chlorite and sodium chlorate. The three pairs of absorbents also gave a high NOx removal efficiency (above 90%), which means that all the absorbents used in the study are very potential to be used to diminish NOx via the wet process. NOx removal efficiency at the same feed gas flow rate increased as the number of fiber and absorbent concentrations is increased. However, NOx removal efficiency is reduced as the feed gas flow rate is increased at the same membrane module and absorbent concentration.
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Jung, Ga-young, Seul-gi Lee, Jun-seo Lee, and Byung-chol Ma. "Experimental Study on Absorption Behavior and Efficiency of Brine in Hazardous Gas Absorption Treatment." ChemEngineering 6, no. 1 (January 4, 2022): 4. http://dx.doi.org/10.3390/chemengineering6010004.

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There have been studies recently on bubble-column scrubbers with low cost and high efficiency for the absorption and treatment of hazardous gases in the event of a chemical spill. Bubble columns are vulnerable to freezing at temperatures below zero because the absorbents generally do not circulate. To address this issue, this study focused on the applicability, absorbed amount, and performance of brine as an absorbent. Under three different temperatures, i.e., −5 °C, −8 °C and −10 °C we examined brine (NaCl, CaCl2, and MgCl2) by varying the concentration required at each temperature. Following the experiments, CaCl2 brine was determined as the optimal brine for its absorption performance and affordability. Based on the experimental results, the absorption performance for ammonia, ethylene oxide, and methylamine, which are hazardous and water-soluble gases among accident preparedness substances (APS), was tested by using ASEPN PLUS. Our results suggested although the efficiency dropped by about 5% to 25% when brine was used as an absorbent, it can be used at the low temperatures because the gas solubility increased with decreasing temperature. Therefore, if brine, as an alternative, is used at temperatures about 15 °C, it can operate efficiently and stably without deterioration in the absorption performance. Given our experimental results and design data on the absorbed amount and absorbent replacement period for major hazardous gases are utilized to prevent bubble columns from freezing, it can be commercially used for small and medium-sized enterprises because it can help reduce installation and operation costs.
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Roslan, H. S., A. N. Mustapa, S. H. Hanipah, A. B. Alias, F. M. Fuad, Á. Martín, and M. J. Cocero. "Characteristics of alginate and soy protein isolates composite aerogels as oil absorbent." IOP Conference Series: Materials Science and Engineering 1257, no. 1 (October 1, 2022): 012045. http://dx.doi.org/10.1088/1757-899x/1257/1/012045.

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Abstract Treating oil spill occurrence is crucial because of the toxic effects on marine life and the environment. Hence, absorption is used for a low-cost oil recovery process, simple mechanism, and sustainability to mitigate such occurrence. Synthetic absorbent is always associated with its poor degradability, which may cause water to turn toxic. Natural materials have been foreseen as excellent absorbent due to their cost-effectiveness, sustainability, and less environmental harm. In this work, alginate/soy protein isolates (SPI) aerogels are synthesized, undergo surface modification with methyltrimethoxysilane (MTMS) and tetraethyl orthosilane (TEOS) solution, and then dried by supercritical CO2 at 110 ± 5 bar and 40 °C in 4h to produce aerogels absorbent. The synthesized absorbents were analyzed via FTIR, TGA, DSC, FESEM, contact angle and oil absorption analysis to determine their physical and chemical properties. Results demonstrated that the hydrophilic surface of the alginate/soy protein isolate could be tailored in a simple surface modification process. Its oil absorption capacity towards the engine oil can reach a range of 9.1-12.1 g/g, comparable to most reported natural absorbents. Thus, the findings in this study show that alginate/ SPI aerogels may have potential as an industry oil absorbent.
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Knyazeva, A. K., M. N. Rakhimov, N. G. Evdokimova, and R. F. Akhmetov. "Selection of the Absorbent and Technological Parameters of the Natural Gas Purification Process with Equal Ratio of Acid Components." Chemistry and Technology of Fuels and Oils 631, no. 3 (2022): 31–34. http://dx.doi.org/10.32935/0023-1169-2022-631-3-31-34.

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Natural gas from most fields contains undesirable acid impurities (hydrogen sulfide and carbon dioxide). The removal of these impurities is traditionally carried out by absorption purification using various absorbents, most often alkanolamines. The main factor influencing the choice of absorbent is the component composition of natural gas (the content of acidic components and their ratio).The paper presents the results of modeling a natural gas purification unit in order to select an absorbent and optimal technological parameters of the process. Studies of the purification process of natural gas with an equal ratio of acidic componentswith monoethanolamine, diethanolamine, methyldiethanolamine and diethanolamine + methyldiethanolamine absorbents were carried out. Based on the results obtained, the technological parameters of the process using an effective absorbent are presented.The results of the analysis of the influence of the main technological parameters on the consumption of energy resources in the process of regeneration of the selected absorbent are also given
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Gilassi, Sina, and Nejat Rahmanian. "CFD Modelling of a Hollow Fibre Membrane for CO2 Removal by Aqueous Amine Solutions of MEA, DEA and MDEA." International Journal of Chemical Reactor Engineering 14, no. 1 (February 1, 2016): 53–61. http://dx.doi.org/10.1515/ijcre-2014-0142.

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AbstractA mass transfer model was developed to capture CO2 from a gas mixture in hollow fibre membrane contactors under laminar flow conditions. The axial and radial diffusions through membrane and convection in tube and shell sides with chemical reaction were investigated. COMSOL software was used to numerically solve a system of non-linear equations with boundary conditions by use of the finite element method. Three different amine solutions of monoethanolamine (MEA), diethanolamine (DEA) and n-methyldiethanolamine (MDEA) were chosen as absorbent in lumen to consider the mass transfer rate of CO2 and its removal efficiency. The modelling results were compared with experimental data available in the literature and a good agreement was observed. The CFD results revealed that MEA had the best performance for CO2 removal as compared to DEA and MDEA under various operating conditions due to the different CO2 loading factor of absorbents. Furthermore, efficiency of CO2 removal was highly dependent on the absorbent concentration and flow rate, increasing of the gas flow rate caused a reduction in gas residence time in the shell and consequently declined CO2 mass transfer. The modelling results showed the effect of absorbent concentration on the CO2 mass transfer was improved due to availability of absorbent reactants at the gas-liquid interface.
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Thamsiriprideeporn, Chanakarn, and Suekane Tetsuya. "Effects of Alkanolamine Absorbents in Integrated Absorption–Mineralization." Minerals 12, no. 11 (October 30, 2022): 1386. http://dx.doi.org/10.3390/min12111386.

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Integrated absorption–mineralization (IAM) involves the transformation of CO2 in a chemical-based solution with brine used as the absorbent to form insoluble carbonates and is promising for carbon capture, utilization, and storage. Various types of absorbents such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and aminomethyl propanol (AMP) were examined in multicycle integrated absorption–mineralization (multicycle IAM) involving absorption, precipitation, and regeneration steps between 20 °C and 25 °C at atmospheric pressure in order to reveal their performance in terms of CO2 absorption and conversion and absorbent degradation. We found that 5 wt.% AMP offered 89.5% CO2 absorption capacity per unit of absorbent converted into the amount of solid carbonate within 4 cycles. In addition, it was moderately degraded by 64.02% during the first cycle and then reduced from 30% to 10% in the next cycle (>2 cycles). In comparison with MEA, which was used as the initial absorbent, AMP provided a fivefold increase in the speed of multicycle IAM.
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Kim, Myung-Gyun, Hyun-Wook Hwang, Antony Nzioka, and Young-Ju Kim. "Enhanced lipid extraction from microalgae in biodiesel production." Chemical Industry 71, no. 2 (2017): 167–74. http://dx.doi.org/10.2298/hemind160327027k.

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In order to secure more effective lipid extraction method, this research investigated new lipid extraction method using laser with absorbent and sought its optimum operation control. In addition, this study compared lipid extraction efficiency and FAME conversion rate between laser extraction method at optimum condition and existing extraction method. Results from experiments for optimizing lipid extraction method using laser showed that the maximum extraction efficiency (81.8%) was attained when using laser with an output capacity of 75Wh/L. Extraction efficiency increased up to 90.8% when microwave treatment as pretreatment process was conducted. Addition of absorbents during lipid extraction process with laser showed higher extraction efficiency than laser and chemical method. It was also found that laser extraction method with absorbent had higher total fatty acid content (853.7 mg/g oil) in extracted lipid than chemical extraction method (825.4 mg/g oil). Furthermore, it had the highest FAME conversion rate (94.2%).
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Dissertations / Theses on the topic "Chemical ABsorbent"

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Ellison, S. L. "The chemical evolution of QSO absorbers." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598835.

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Using quasar absorption lines as a probe of the high redshift universe is a powerful tool in the field of chemical evolution. In this thesis, I consider the elemental abundances in absorbers that correspond to a variety of environments, ranging from high redshift galaxies to the low density intergalactic medium. I firstly address the question of abundances in intermediate redshift (zabs < 1.5) damped Lyα systems (DLAs), objects believed to correspond to the progenitors of present day massive galaxies. I present Hubble Space Telescope (HST) spectra of six intermediate redshift DLAs which have been supplemented with high resolution spectroscopy obtained with the high resolution echelle spectrograph (HIRES) on the Keck telescope. The chemical abundances of a range of elements are investigated and compared with local Galactic values in order to gain an insight into the metallicities, dust-to-gas ratios and star formation histories of these systems. The results from this work have inspired a new survey for DLAs based on a radio-selected sample of QSOs. The motivation for this endeavour has been to determine the extent to which our current view of distant galaxies is obscured by dust. I present intermediate resolution spectra obtained at the Anglo-Australian Telescope (AAT) from which DLAs may be identified. The number statistics of the newly discovered DLAs are analysed in order to determine whether obscuration by dust of background QSOs causes a significant observational bias. Finally, I consider the metallicity of the IGM by studying C IV systems associated with the Lyα forest at z ~ 3. The extent to which the IGM has been polluted with metals will provide important clues to the enrichment mechanism. I firstly investigate the column density distribution function of strong C IV absorbers associated with high column density Lyα clouds. This work is then extended to consider the C IV/H 1 ratio in low column density absorbers which are associated with physically less dense material. The spectra of two high redshift QSOs are analysed using two different techniques, both of which are critically assessed using synthetic spectra.
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Grubbs, Laura Michelle Sprunger. "Characterization of Novel Solvents and Absorbents for Chemical Separations." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc67989/.

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Predictive methods have been employed to characterize chemical separation mediums including solvents and absorbents. These studies included creating Abraham solvation parameter models for room-temperature ionic liquids (RTILs) utilizing novel ion-specific and group contribution methodologies, polydimethyl siloxane (PDMS) utilizing standard methodology, and the micelles cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) utilizing a combined experimental setup methodology with indicator variables. These predictive models allows for the characterization of both standard and new chemicals for use in chemical separations including gas chromatography (GC), solid phase microextraction (SPME), and micellar electrokinetic chromatography (MEKC). Gas-to-RTIL and water-to-RTIL predictive models were created with a standard deviation of 0.112 and 0.139 log units, respectively, for the ion-specific model and with a standard deviation of 0.155 and 0.177 log units, respectively, for the group contribution fragment method. Enthalpy of solvation for solutes dissolved into ionic liquids predictive models were created with ion-specific coefficients to within standard deviations of 1.7 kJ/mol. These models allow for the characterization of studied ionic liquids as well as prediction of solute-solvent properties of previously unstudied ionic liquids. Predictive models were created for the logarithm of solute's gas-to-fiber sorption and water-to-fiber sorption coefficient for polydimethyl siloxane for wet and dry conditions. These models were created to standard deviations of 0.198 and 0.122 logunits for gas-to-PDMS wet and dry, respectively, as well as 0.164 and 0.134 log units for water-to-PDMS wet and dry, respectively. These models are particularly useful in solid phase microextraction separations. Micelles were studied to create predictive models of the measured micelle-water partition coefficient as well as models of measured MEKC chromatographic retention factors for CTAB and SDS. The resultant predictive models were created with standard deviations of 0.190 log units for the logarithm of the mole fraction concentration of water-to-CTAB, 0.171 log units for the combined logarithms of both the mole fraction concentration of water-to-CTAB and measured MEKC chromatographic retention factors for CTAB, and 0.153 log units for the combined logarithms of both the mole fraction concentration of water-to-SDS and measured MEKC chromatographic retention factors for SDS.
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Tontiwachwuthikul, Paitoon. "New pilot plant technique for designing gas absorbers with chemical reactions." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/32182.

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Gas absorption with chemical reaction is an important unit operation in the chemical and petroleum industries for the selective removal of components from industrial gas streams. Apart from choosing absorption media, the most difficult problems facing the design engineer are the sizing and performance prediction of the absorption tower due to the scarcity of fundamental design data, especially when novel absorption media and/or packings are used. The solubility of carbon dioxide in 2 and 3 M solutions of 2-amino-2-methyl-1-propanol (AMP), which is a newly introduced absorbent, was determined at 20, 40, 60 and 80 °C and for CO₂ partial pressures ranging from approximately 1 to 100 kPa. The results were interpreted with a modified Kent-Eisenberg model which predicted the present and previous experimental results well. The absorption capacities of AMP and monoethanolamine (MEA) solutions were also compared. Detailed concentration and temperature measurements were reported for the absorption of carbon dioxide from air into NaOH, MEA and AMP solutions. A full-length absorber (0.1 m ID, packed with 12.7 mm Berl Saddles up to heights of 6.55 m) was used. It was operated in countercurrent mode and at 30 to 75 % flooding velocities which are typical for gas absorber operations. The following ranges of operating conditions were employed: superficial gas flow rate 11.1 to 14.8 mol/m² s; superficial liquid flow rate 9.5 to 13.5 m³/m² h; feed CO₂ concentration 11.5 to 19.8 %; total absorbent concentration 1.2 to 3.8 kmol/m³; liquid feed temperature 14 to 20 °C; total pressure 103 kPa. The measurements for the CO₂-NaOH and CO₂-MEA systems were compared with predictions from a previously developed mathematical model. Generally good agreement was obtained except at high CO₂ loadings of MEA solutions. Compared with MEA, AMP was found to have superior CO₂ absorption capacities and inferior mass transfer rates. A new procedure, called the Pilot Plant Technique (PPT), for designing gas absorbers with chemical reactions has been developed. The PPT is primarily intended for designing absorbers for which fundamental design information is lacking. It is based on the premise that full-length absorption columns can be sized by making a minimum number of tests using a small-scale pilot plant. Two special features of the PPT are (i) the details of hydrodynamic parameters (i.e. mass transfer coefficients, effective interfacial area and liquid hold-up) and the physico-chemical information of the system (e.g. reaction mechanism, reaction rate constants) need not be known and (ii) complex calculations are avoided. Using the PPT to size the height or to predict the performance of a given full-length absorber, the specific absorption rate, which is the essential information, can be measured directly using the pilot plant model (PPM) column if both columns have the same hydrodynamic conditions. This can be achieved by using the same type and size of packing in the PPM and the full-length columns and ensuring that the end and wall effects are negligible. The PPM column must also be operated at the same superficial fluid velocities as those of the full-length column. The specific absorption rate was then obtained from the gradient of the fluid composition profile along the PPM column. The validity of the PPT was demonstrated by determining the height and predicting the performance of the full-length column in which carbon dioxide was absorbed from air by aqueous solutions of NaOH and AMP at various operating conditions; good agreement was obtained.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Trease, Claire Heather. "Design and development of novel absorber coating for solar collector applications." Thesis, Kingston University, 2017. http://eprints.kingston.ac.uk/41036/.

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Global average power consumption is 17 terawatts (10[to the power of]12W) and the rate of solar energy received at the Earth's surface is more than 120 petawatts (10[to the power of]15W). Therefore, the earth receives as much solar energy in one day as is used by the entire world in 20 years. Solar thermal collectors use absorber coatings and layers to convert incident radiation, via photothermal conversion, into useful energy i.e. heat. Re-radiation of this heat is minimised using a solar selective surface. Patterning non-thermal curing epoxy resins, in the micron scale, using electrohydrodynamic instability (EHD) patterning, could mitigate some of the challenges presented by other materials and methods used to produce these surfaces such as cost. Therefore, this was the objective of this study. As a contribution to the field of electrohydrodynamic instability patterning, the method of using this process to shape a thin, non-thermal curing epoxy resin film, was developed and the materials and equipment used are presented. Epoxy pillared surfaces, with pillar spcings from 3-200 [micrometres], were manufactured on silicon substrates using 30, 61 or 162 V and electrode gaps ranging from 3- 40 [micrometres]. A way of replicating the fabricated surfaces using moulding was also developed and is also described here. The patterned surfaces were replicated onto various substrates and were tested for their interaction with infrared (IR) radiation. In order to explore the range of versatility of theis technique for fabricating functional surfaces the structures surfaces were also tested as sustrates for tissue culture. To gain a better understanding and hence control over the use of electrohydrodynamic instability patterning with an epoxy resin, theories and numerical models of the process of electrohydrodynamic instability patterning were examined. Comparisons between predictions of results given by theory and our practical results are discussed since it was found that there was more disagreement between our results and theory when lower electric fields were being used. The studies of the interaction of the surfaces with IR radiation, and for use as tissue culture substrates, is also assessed and commented on. Lastly improvements that could be made and future work that could be undertaken is suggested.
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Youh, Meng-Jey. "Development of microwave absorbing diamond coated fibres." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326038.

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Hales, Joel McCajah. "CHEMICAL STRUCTURE - NONLINEAR OPTICAL PROPERTY RELATIONSHIPS FOR A SERIES OF TWO-PHOTON ABSORBING FLUORENE MOLECULES." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4403.

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This dissertation reports on the investigation of two-photon absorption (2PA) in a series of fluorenyl molecules. Several current and emerging technologies exploit this optical nonlinearity including two-photon fluorescence imaging, three-dimensional microfabrication, site-specific photodynamic cancer therapy and biological caging studies. The two key features of this nonlinearity which make it an ideal candidate for the above applications are its quadratic dependence on the incident irradiance and the improved penetration into absorbing media that it affords. As a consequence of the burgeoning field which exploits 2PA, it is a goal to find materials that exhibit strong two-photon absorbing capabilities. Organic materials are promising candidates for 2PA applications because their material properties can be tailored through molecular engineering thereby facilitating optimization of their nonlinear optical properties. Fluorene derivatives are particularly interesting since they possess high photochemical stability for organic molecules and are generally strongly fluorescent. By systematically altering the structural properties in a series of fluorenyl molecules, we have determined how these changes affect their two-photon absorbing capabilities. This was accomplished through characterization of both the strength and location of their 2PA spectra. In order to ensure the validity of these results, three separate nonlinear characterization techniques were employed: two-photon fluorescence spectroscopy, white-light continuum pump-probe spectroscopy, and the Z-scan technique. In addition, full linear spectroscopic characterization was performed on these molecules along with supplementary quantum chemical calculations to obtain certain molecular properties that might impact the nonlinearity. Different designs in chemical architecture allowed investigation of the effects of symmetry, solvism, donor-acceptor strengths, conjugation length, and multi-branched geometries on the two-photon absorbing properties of these molecules. In addition, the means to enhance 2PA via intermediate state resonances was investigated. To provide plausible explanations for the experimentally observed trends, a conceptually simple three level model was employed. The subsequent correlations found between chemical structure and the linear and nonlinear optical properties of these molecules provided definitive conclusions on how to properly optimize their two-photon absorbing capabilities. The resulting large nonlinearities found in these molecules have already shown promise in a variety of the aforementioned applications.
Ph.D.
Optics and Photonics
Optics and Photonics;
Optics
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Gulston, Melanie Katharine. "The effects of the sunscreen chemicals Padimate-O and 2-ethylhexyl-P-methoxycinnamate on DNA." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301520.

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Boström, Tobias. "Solution-Chemically Derived Spectrally Selective Solar Absorbers : With System Perspectives on Solar Heating." Doctoral thesis, Uppsala University, Department of Engineering Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7160.

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This thesis consists of two parts, one dominating part concerning spectrally selective solar absorbers and one dealing with thermal solar systems. The appended papers I to VIII concern the solar absorber part, papers dealing with the systems part have not been included in the thesis.

A new spectrally selective absorber derived from a novel solution-chemistry method has been developed and optimized. The main objective was to investigate the potential of the spectrally selective surface. Some of the questions at issue were; would it be possible to create a suitable absorber composite using this method, how high selectivity could be obtained, could the performance be enhanced by using anti-reflection coatings, which was the optimal layer composition, would the thin films be durable and what was the structure and morphology like on a nano scale? The absorber consists of absorbing thin films of nickel nano-particles embedded in a dielectric matrix of alumina and an overlying anti-reflection film consisting of one of the following materials silica, hybrid-silica, alumina or silica-titania. Solution and sol-gel chemistry were used in the process. The thin films were spin-coated onto an aluminum substrate followed by a heat-treatment that generated the multi layer selective solar absorber.

The optical constants for the thin film materials in question were determined. An optimal three layer structure was modeled using the experimentally determined optical constants. The theoretical three layer stack was experimentally confirmed and achieved a solar absorptance of 0.97 and a thermal emittance of 0.05 which definitely are commercially competitive values. The configuration of the three layer stack is: an 80%nickel-20%alumina film at the base, a 40%nickel-60%alumina film in the middle and a silica or hybrid-silica film at the top. The three layer absorber was subjected to high temperature and condensation accelerated ageing tests designed by IEA Task 27. The condensation test did not degrade the absorber whatsoever but the high temperature test did reveal some oxidation of the nickel particles. The oxidation occurs initially and then stops. A formed nickel-oxide layer hinders further oxidation. The level of oxidation is small and the absorber is qualified according to the IEA Task 27 test procedure.

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Schmidt, David Daniel. "Simulating aerosol formation and effects in NOx absorption in oxy-fired boiler gas processing units using Aspen Plus." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/15304.

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Master of Science
Department of Chemical Engineering
Larry Erickson
Oxy-fired boilers are receiving increasing focus as a potential response to reduced boiler emissions limits and greenhouse gas legislation. Among the challenges in cleaning boiler gas for sequestration is attaining the necessary purity of the CO[subscript]2. A key component in the oxy-fired cleaning path is high purity SO[subscript]x and NO[subscript]x removal, often through absorption using the lead-chamber or similar process. Aerosol formation has been found to be a source of product contamination in many flue gas absorption processes. A number of authors presented simulation methods to determine the formation of aerosols in gas absorption. But these methods are numerically challenging and not suitable for day-to-day analysis of live processes in the field. The goal of this study is to devise a simple and practical method to predict the potential for and effect of aerosol formation in gas absorption using information from Aspen Plus, a commonly used process simulation tool. The NO[subscript]x absorber in an oxy-fired boiler CO[subscript]2 purification system is used as a basis for this investigation. A comprehensive review of available data suitable for simulating NO[subscript]x absorption in an oxy-fired boiler slipstream is presented. Reaction rates for eight reactions in both liquid and vapor phases are covered. These are entered into an Aspen Plus simulation using a RadFrac block for both rate-based and equilibrium reactions. A detailed description of the simulation format is given. The resulting simulation was compared to a previously published simulation and process data with good agreement. An overall description of the aerosol formation mechanism is presented, along with an estimate of expected aerosol nuclei reaching the NO[subscript]x absorption process. A method to estimate aerosol quantities produced based on inlet gas nuclei concentration and available condensable water vapor is presented. To estimate aerosol composition and emissions, an exit gas slipstream is used to equilibrate with a pure water aerosol using an Aspen Plus Equilibrium Reactor block. Changing the composition of the initial aerosol feed liquid suggests that the location of aerosol formation may influence the final composition and emissions.
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Unsworth, Christopher Adam. "The use of visible light absorbing bismuth-containing semiconductors as heterogeneous photocatalysts for selective chemical transformations." Thesis, University of York, 2017. http://etheses.whiterose.ac.uk/19361/.

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Bismuth-containing semiconducting materials were used as visible light absorbing heterogeneous photocatalysts for selective chemical transformations. The work demonstrates the importance of kinetic control in achieving selectivity; either through photocatalyst inhibition or through the presence of reagents capable of fast reactions with known intermediates. Bismuth oxide (β-Bi2O3), bismuth ferrite (BiFeO3), bismuth tungstate microflowers (Bi2WO6) and bismuth vanadate nanoparticles (nan-BiVO4) were synthesised and characterised by PXRD, SEM, DRUVS and BET. The bismuth-containing oxides were compared as photocatalysts for the aerobic oxidation of benzyl alcohol. The highest benzyl alcohol conversion (88%) and benzaldehyde selectivity (95%) was achieved with the use of nan-BiVO4. Further modifications to nan-BiVO4 resulted in materials that were less active for selective benzyl alcohol oxidation than unmodified nan-BiVO4. Further study of nan-BiVO4 as a heterogeneous photocatalysts for the selective oxidation of para-substituted benzyl alcohols was carried out. It was found that alcohol conversions and aldehyde selectivities were affected by by-product inhibition. The addition of 1 mol% 4-methoxybenzoic acid significantly reduced 4-methoxybenzyl alcohol conversion (to 49%). Isotopically labelled benzyl alcohols were used to show that α C-H bond cleavage was not rate limiting. However, changes in charge carrier lifetimes observed using TRPLS suggested that the charge carriers associated to the lifetimes observed were relevant to benzyl alcohol oxidation. Bismuth-containing semiconductors were also investigated as trifluoromethylation heterogeneous photocatalysts. Nan-BiVO4 was capable of oxytrifluoromethylation of styrene via the reduction of Umemoto’s reagents. The highly selective reaction produced the corresponding trifluoromethylated ketone in an 88% yield. Platinised bismuth tungstate (0.15-Pt-Bi2WO6) was found to give high conversions and product selectivities for the formation of Photo-Giese products (phenylacetic acid conversion = 99%, Photo-Giese product selectivity = 94%). Several coupling products were synthesised from different carboxylic acids and electron deficient alkenes. Competitive adsorption from by-products inhibition had an impact on acid conversions and Photo-Giese product selectivities.
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Books on the topic "Chemical ABsorbent"

1

Das, Tomi Nath. Recent improvements in chemical dosimetric protocols for accurate measurements of absorbed dose in pulse radiolysis experiments. Mumbai: Bhabha Atomic Research Centre, 2008.

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Shilyaev, Mihail, Elena Hromova, Aleksandr Bogomolov, A. Pavlenko, and V. Butov. Modeling of hydrodynamics and heat and mass transfer in dispersed media. ru: INFRA-M Academic Publishing LLC., 2022. http://dx.doi.org/10.12737/1865376.

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The monograph presents methods for calculating the dehydration of wet granular materials in industrial centrifuges, filter presses and vacuum filters under the influence of gravitational forces, as well as by purging the granular layer with dry air with elevated temperature; physical and mathematical models of gas absorption and the theory of capturing submicron dust by condensation in foam, centrifugal bubbling apparatus and hollow nozzle scrubbers, packing columns and tubular absorbers; physical and mathematical models of dry adsorption of gases in packing columns and flues by injecting a dispersed adsorbent into the flow are presented, a method for determining the phase equilibrium constants of sorption processes based on the developed models is proposed; physical and mathematical modeling and analysis of the combustion process of dispersed solid ash fuel in a four-stage cyclone gorenje is carried out. the furnace. It can be useful in the educational process for a number of specialties, in particular thermal power engineering, chemical-technological, metallurgical profiles, environmentalists, as well as for researchers and graduate students and in engineering practice.
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Lippmann, Morton, and Richard B. Schlesinger. Effects of Contaminants on Human Health. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190688622.003.0006.

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This chapter describes the methodology used for evaluating potential human health effects resulting from exposure to environmental chemicals. It discusses the concept of the dose-response relationship, and reviews the processes by which chemicals may be delivered to and absorbed by the body. Concepts of the metabolic transformation of absorbed chemical are provided, as are the potential for storage and excretion. It explores the biological mechanisms and pathways underlying specific responses to chemical contaminants, which range from disruption of physiology to alteration of biochemical pathways and hereditary material. A discussion of responses due to exposure to mixtures of chemicals is provided.
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Danckwerts, P. V., and T. Hobler. Mass Transfer and Absorbers: International Series of Monographs in Chemical Engineering. Elsevier Science & Technology Books, 2013.

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Gore, Mike, ed. Spectrophotometry and Spectrofluorimetry. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780199638130.001.0001.

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This book describes the theory and practical applications of many analytical techniques based upon the light absorbing properties of molecules. Such techniques form the basis of routine tests in chemical, biological, and medical science laboratories. Practical advice is given, from experts in the different topics, together with lists of useful literature.
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Kosuge, Koji. Chemistry of Non-stoichiometric Compounds. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780198555551.001.0001.

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As inorganic materials are put to more and more practical uses--mainly in electric, magnetic, and optical devices--materials scientists must have an increasingly sophisticated understanding of the chemical and physical properties of inorganic compounds. This volume--the first of its kind in twenty years--provides a unified presentation of the chemistry of non-stoichiometric compounds based on statistical thermodynamics and structural inorganic chemistry. Four modern examples of non-stoichiometric compounds--ionic conducting compounds, hydrogen absorbing alloys, magnetic materials, and electrical materials--are discussed in detail. Students and researchers in structural inorganic chemistry, crystallography, materials science, and solid state physics will find this much-needed book both practical and informative.
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Barton, Gregory A. To the Empire and Beyond. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199642533.003.0007.

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This chapter traces the expansion of industrial agricultural methods after the Second World War. Western governments and the Food and Agriculture Organization pushed for increased use of chemical fertilizers to aid development and resist Soviet encroachment. Meanwhile small groups of organic farmers and gardeners adopted Howard’s methods in the Anglo-sphere and elsewhere in the world. European movements paralleled these efforts and absorbed the basic principles of the Indore Method. British parliament debated the merits of organic farming, but Howard failed to persuade the government to adopt his policies. Southern Rhodesia, however, did implement his ideas in law. Desiccation theory aided his attempts in South Africa and elsewhere, and Louise Howard, after Albert’s death, kept alive a wide network of activists with her publications.
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Dragan, Ecaterina Stela. Advanced Separations by Specialized Sorbents. Taylor & Francis Group, 2014.

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Dragan, Ecaterina Stela. Advanced Separations by Specialized Sorbents. Taylor & Francis Group, 2021.

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Dragan, Ecaterina Stela. Advanced Separations by Specialized Sorbents. Taylor & Francis Group, 2015.

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Book chapters on the topic "Chemical ABsorbent"

1

Kulkarni, Varsha P., Jill Bechtold, and Jian Ge. "Element Abundances in Damped Lyman-Alpha Quasar Absorbers." In Chemical Evolution from Zero to High Redshift, 275. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-540-48360-1_58.

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Kulkarni, Varsha P., John M. Hill, Ray J. Weymann, Lisa J. Storrie-Lombardi, Marcia J. Rieke, Glenn Schneider, Rodger I. Thompson, and Buell Jannuzi. "Search for a High-Redshift Damped Lyman-Alpha Absorber with NICMOS." In Chemical Evolution from Zero to High Redshift, 262–67. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-540-48360-1_55.

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Cesar, C. L., M. N. Islam, C. E. Soccolich, R. D. Feldman, R. F. Austin, and K. R. German. "Femtosecond Color Center Lasers near 2.8 µm with HgCdTe Multiple Quantum Well Saturable Absorber." In Springer Series in Chemical Physics, 17–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-84269-6_5.

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Brovelli, L. R., U. Keller, and T. H. Chiu. "Operation Parameters of Antiresonant Fabry-Perot Saturable Absorbers for Passively Mode-Locked Solid-State Lasers." In Springer Series in Chemical Physics, 174–75. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/978-3-642-85176-6_59.

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Sutter, D. H., I. D. Jung, N. Matuschek, F. Morier-Genoud, F. X. Kärtner, V. Scheuer, M. Tilsch, T. Tschudi, and U. Keller. "Broadband Operation of a Ti:Sapphire Laser Using Novel Double-Chirped Mirrors and Semiconductor Saturable Absorbers." In Springer Series in Chemical Physics, 11–13. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72289-9_3.

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Morgan, Lynette. "Substrate-based Hydroponic Systems." In Hydroponics and protected cultivation: a practical guide, 77–99. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0006.

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Abstract This chapter focuses on substrate-based hydroponic systems. The main purpose of the substrate in hydroponic systems is to provide plant support, allowing roots to grow throughout the medium absorbing water and nutrients from the nutrient solution. Topics discussed are properties of hydroponic substrates, open and closed soilless systems, common hydroponic substrates, substrates and water-holding capacity, substrates and oversaturation, matching substrates to crop species, physical properties of soilless substrates, chemical properties of hydroponic substrates, nutrient delivery in substrate systems, irrigation and moisture control in substrates, and microbial populations in substrates.
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Morgan, Lynette. "Substrate-based Hydroponic Systems." In Hydroponics and protected cultivation: a practical guide, 77–99. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0077.

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Abstract This chapter focuses on substrate-based hydroponic systems. The main purpose of the substrate in hydroponic systems is to provide plant support, allowing roots to grow throughout the medium absorbing water and nutrients from the nutrient solution. Topics discussed are properties of hydroponic substrates, open and closed soilless systems, common hydroponic substrates, substrates and water-holding capacity, substrates and oversaturation, matching substrates to crop species, physical properties of soilless substrates, chemical properties of hydroponic substrates, nutrient delivery in substrate systems, irrigation and moisture control in substrates, and microbial populations in substrates.
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Roth, Katherine C., James M. Bauer, and Kevin T. C. Jim. "The z = 1.6748 C I Absorber Toward the QSO PKS 1756+237." In Chemical Evolution from Zero to High Redshift, 278. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-540-48360-1_61.

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Neumann, Karsten, Mirka-Kristin Verhoefen, Ingrid Weber, Clemens Glaubitz, and Josef Wachtveitl. "Primary Reaction Dynamics of Green Absorbing Proteorhodopsin WT and D97N Mutant Observed by fs Infrared and Visible Spectroscopy." In Springer Series in Chemical Physics, 580–82. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-95946-5_188.

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Fritze - v. Alvensleben, Uta. "Chemical Evolution of (Proto-) Galactic Disks and Metal Abundances of Damped Lyα Absorbers." In QSO Absorption Lines, 81–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-540-49458-4_14.

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Conference papers on the topic "Chemical ABsorbent"

1

Cai, Weihua, Mihir Sen, and Samuel Paolucci. "Dynamic Modeling of an Absorption Refrigeration System Using Ionic Liquids." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41335.

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Ionic liquids are generally non-volatile, non-toxic, and nonflammable with high heat capacity, high density, and high thermal and chemical stability. This paper considers their use as absorbents in an absorption refrigeration cycle. A dynamic model of a single-effect absorption refrigeration cycle using ionic liquids as absorbent is developed. Modeling of the cycle performance requires thermodynamic properties which are obtained from an equation of state for the refrigerant-absorbent mixture (solution). The transient response of the cycle is investigated. Some design and operating parameters that affect the cycle performance are identified.
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Mindaryani, Aswati, Wiratni Budhijanto, and Roberto Delta Narendratama. "Co2 desorption from glycerol for reusable absorbent." In INTERNATIONAL SEMINAR ON FUNDAMENTAL AND APPLICATION OF CHEMICAL ENGINEERING 2016 (ISFAChE 2016): Proceedings of the 3rd International Seminar on Fundamental and Application of Chemical Engineering 2016. Author(s), 2017. http://dx.doi.org/10.1063/1.4982279.

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Bratu, Mihai, Luoana Florentina Pascu, Ileana Nicolescu, and Ionut Nicolae Cristea. "MICROSTRUCTURAL AND CHEMICAL CHARACTERIZATION OF SOME WASTES FOR PHONO ABSORBENT MATERIALS OBTAINING." In International Symposium "The Environment and the Industry". National Research and Development Institute for Industrial Ecology, 2018. http://dx.doi.org/10.21698/simi.2018.fp49.

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"Decolorisation Treatment of Wastewater Containing Reactive Yellow 15 Using Herbal absorbent of Wheat Husk." In 3rd International Conference on Biological, Chemical and Environmental Sciences. International Institute of Chemical, Biological & Environmental Engineering, 2015. http://dx.doi.org/10.15242/iicbe.c0915062.

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Xu, Jiao, and Weijiang Zhang. "The Application of 10B Enriched Boric Acid in Nuclear Power Industry." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29042.

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Nowadays, boron acid is used widely in nuclear power station as the chemical controlling remedy by making use of 10B as the effective neutron absorbent. But the natural element boron includes 10B just 20% (mass fraction), all the rest is 11B which is very weak at absorbing neutron. This paper brings forward a way to improve the effect of chemical controlling remedy on the nuclear power station through taking 10B enriched boron acid as the substitution of the natural one. If this technological measurement is taken, the operation control of nuclear reaction would get at high level. Not only the amount of boron acid waste would drop suddenly, but the amount of all kinds of chemical agents added in the cooling circulation would lower down sharply. So, many complex chemistry problems in the cooling system could be solved, such as erosion of devices, worse quality of wastewater and consume of chemical agents, etc.
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Karim, Md Anwarul, Sharmin Sultana Dipti, and Md Abul Kalam Azad. "Cost Effective and Efficient Absorbent Brick Sand Particles (Surkhi) for Removal of Chromium from Solution." In 2021 International Conference on Computer, Communication, Chemical, Materials and Electronic Engineering (IC4ME2). IEEE, 2021. http://dx.doi.org/10.1109/ic4me253898.2021.9768637.

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Sen, Mihir, and Samuel Paolucci. "The Use of Ionic Liquids in Refrigeration." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14712.

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Ionic liquids are salts, usually with organic cations and inorganic anions, that are liquid at room temperature. There are a wide variety of ionic liquids that can be synthesized with different properties for different applications. They are generally non-volatile, non-toxic, and non-flammable with high heat capacity, high density, high thermal and chemical stability. We propose its use as an absorbent in an absorption refrigeration cycle. The refrigerant in this case would be a gas such as carbon dioxide. The present work deals with the desirable properties of ionic liquids for this application. For example, the absorbent must have a high solubility, and the heat and mass transfer coefficients of the absorbent-refrigerant solution must be large. The viscosity of the mixture, on the other hand, should not be so large as to make its pumping difficult.
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Habibi, Davood, Zahra Moslemi, and Ahmad Asgharzadeh. "Effects of super absorbent polymer and plant growth promoting rhizobacteria (PGPR) on yield and oxidative damage of maize under drought stress." In 2010 International Conference on Chemistry and Chemical Engineering (ICCCE). IEEE, 2010. http://dx.doi.org/10.1109/iccceng.2010.5560441.

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Morante, M. A., G. Stewart, B. Culshaw, and J. M. López-Higuera. "Influence Of The Non-Linear Characteristic Of The Laser Source On Detected Signals In Derivative Spectroscopy For Gas Analysis." In Laser Applications to Chemical and Environmental Analysis. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/lacea.1998.lmc.17.

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Derivative spectroscopy, or wavelength modulation spectroscopy (WMS), consists in obtaining the concentration of a molecular absorbent by modulating the output wavelength of the optical source and detecting at one of the harmonics of the modulation frequency. The first and second harmonic signals are proportional to the first and second derivatives of the absorption feature, respectively, for small WM amplitude. The maximum gradient of the first and the absolute maximum of the second harmonic signal, which are located at the absorption line center, are directly proportional to the species concentration. [1-3]. In practice, the output power/current characteristic of the laser has a slight degree of nonlinearity which influences the form of the recovered signal. As a result, the detected derivative trace displays a non-constant baseline that degrades the absorption signal. Furthermore, such baseline does not remain unchanged over the operating period of the source, because it is influenced by environmental factors and aging. In this work we analyze the effect of the mentioned nonlinear laser characteristic on the detected harmonic signal, and we propose a simple post-detection processing method to capture the baseline from the demodulated signal in real time.
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Supriyanto, Yoga Adesca Cahyadi, Muhammad Heprizon, Muhammad Arief Guswandi, and Wahyu Prayogi. "Biocomposite of Super Absorbent Polymer (SAP) from rice straw — Polyacrylamida (PAM) and corncob-Polyacrylamida (PAM): Synthesis and characterization." In 2016 2nd International Conference of Industrial, Mechanical, Electrical, and Chemical Engineering (ICIMECE). IEEE, 2016. http://dx.doi.org/10.1109/icimece.2016.7910433.

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Reports on the topic "Chemical ABsorbent"

1

Buettner, Leonard C., John J. Mahle, George Wagner, Tara Sewell, Nicole Fletcher, and David K. Friday. Absorbent Analysis of Anniston Chemical Agent Disposal Facility Munition Demilitarization Building (MDB) Banks 1 and 2 Filter Samples Following Completion of The GB Agent and VX Rocket Campaigns. Fort Belvoir, VA: Defense Technical Information Center, January 2013. http://dx.doi.org/10.21236/ada571049.

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Shapira, Roni, Judith Grizzle, Nachman Paster, Mark Pines, and Chamindrani Mendis-Handagama. Novel Approach to Mycotoxin Detoxification in Farm Animals Using Probiotics Added to Feed Stuffs. United States Department of Agriculture, May 2010. http://dx.doi.org/10.32747/2010.7592115.bard.

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T-2 toxin, a toxic product belongs to the trichothecene mycotoxins, attracts major interest because of its severe detrimental effects on the health of human and farm animals. The occurrence of trichothecenes contamination is global and they are very resistant to physical or chemical detoxification techniques. Trichothecenes are absorbed in the small intestine into the blood stream. The hypothesis of this project was to develop a protecting system using probiotic bacteria that will express trichothecene 3-O-acetyltransferase (Tri101) that convert T-2 to a less toxic intermediate to reduce ingested levels in-situ. The major obstacle that we had faced during the project is the absence of stable and efficient expression vectors in probiotics. Most of the project period was invested to screen and isolate strong promoter to express high amounts of the detoxify enzyme on one hand and to stabilize the expression vector on the other hand. In order to estimate the detoxification capacity of the isolated promoters we had developed two very sensitive bioassays.The first system was based on Saccharomyces cerevisiae cells expressing the green fluorescent protein (GFP). Human liver cells proliferation was used as the second bioassay system.Using both systems we were able to prove actual detoxification on living cells by probiotic bacteria expressing Tri101. The first step was the isolation of already discovered strong promoters from lactic acid bacteria, cloning them downstream the Tri101 gene and transformed vectors to E. coli, a lactic acid bacteria strain Lactococcuslactis MG1363, and a probiotic strain of Lactobacillus casei. All plasmid constructs transformed to L. casei were unstable. The promoter designated lacA found to be the most efficient in reducing T-2 from the growth media of E. coli and L. lactis. A prompter library was generated from L. casei in order to isolate authentic probiotic promoters. Seven promoters were isolated, cloned downstream Tri101, transformed to bacteria and their detoxification capability was compared. One of those prompters, designated P201 showed a relatively high efficiency in detoxification. Sequence analysis of the promoter region of P201 and another promoter, P41, revealed the consensus region recognized by the sigma factor. We further attempted to isolate an inducible, strong promoter by comparing the protein profiles of L. casei grown in the presence of 0.3% bile salt (mimicking intestine conditions). Six spots that were consistently overexpressed in the presence of bile salts were isolated and identified. Their promoter reigns are now under investigation and characterization.
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3

Zhou, Ting, Roni Shapira, Peter Pauls, Nachman Paster, and Mark Pines. Biological Detoxification of the Mycotoxin Deoxynivalenol (DON) to Improve Safety of Animal Feed and Food. United States Department of Agriculture, July 2010. http://dx.doi.org/10.32747/2010.7613885.bard.

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The trichothecene deoxynivalenol (DON, vomitoxin), one of the most common mycotoxin contaminants of grains, is produced by members of the Fusarium genus. DON poses a health risk to consumers and impairs livestock performance because it causes feed refusal, nausea, vomiting, diarrhea, hemolytic effects and cellular injury. The occurrence of trichothecenes contamination is global and they are very resistant to physical or chemical detoxification techniques. Trichothecenes are absorbed in the small intestine into the blood stream. The overall objective of this project was to develop a protecting system using probiotic bacteria that will express trichothecene 3-O-acetyltransferase (Tri101) that convert T-2 to a less toxic intermediate to reduce ingested levels in-situ. The major obstacle that we had faced during the project is the absence of stable and efficient expression vectors in probiotics. Most of the project period was invested to screen and isolate strong promoter to express high amounts of the detoxify enzyme on one hand and to stabilize the expression vector on the other hand. In order to estimate the detoxification capacity of the isolated promoters we had developed two very sensitive bioassays.The first system was based on Saccharomyces cerevisiae cells expressing the green fluorescent protein (GFP). Human liver cells proliferation was used as the second bioassay system.Using both systems we were able to prove actual detoxification on living cells by probiotic bacteria expressing Tri101. The first step was the isolation of already discovered strong promoters from lactic acid bacteria, cloning them downstream the Tri101 gene and transformed vectors to E. coli, a lactic acid bacteria strain Lactococcuslactis MG1363, and a probiotic strain of Lactobacillus casei. All plasmid constructs transformed to L. casei were unstable. The promoter designated lacA found to be the most efficient in reducing T-2 from the growth media of E. coli and L. lactis. A prompter library was generated from L. casei in order to isolate authentic probiotic promoters. Seven promoters were isolated, cloned downstream Tri101, transformed to bacteria and their detoxification capability was compared. One of those prompters, designated P201 showed a relatively high efficiency in detoxification. Sequence analysis of the promoter region of P201 and another promoter, P41, revealed the consensus region recognized by the sigma factor. We further attempted to isolate an inducible, strong promoter by comparing the protein profiles of L. casei grown in the presence of 0.3% bile salt (mimicking intestine conditions). Six spots that were consistently overexpressed in the presence of bile salts were isolated and identified. Their promoter reigns are now under investigation and characterization.
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4

Lahav, Ori, Albert Heber, and David Broday. Elimination of emissions of ammonia and hydrogen sulfide from confined animal and feeding operations (CAFO) using an adsorption/liquid-redox process with biological regeneration. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7695589.bard.

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Abstract:
The project was originally aimed at investigating and developing new efficient methods for cost effective removal of ammonia (NH₃) and hydrogen sulfide (H₂S) from Concentrated Animal Feeding Operations (CAFO), in particular broiler and laying houses (NH₃) and hog houses (H₂S). In both cases, the principal idea was to design and operate a dedicated air collection system that would be used for the treatment of the gases, and that would work independently from the general ventilation system. The advantages envisaged: (1) if collected at a point close to the source of generation, pollutants would arrive at the treatment system at higher concentrations; (2) the air in the vicinity of the animals would be cleaner, a fact that would promote animal growth rates; and (3) collection efficiency would be improved and adverse environmental impact reduced. For practical reasons, the project was divided in two: one effort concentrated on NH₃₍g₎ removal from chicken houses and another on H₂S₍g₎ removal from hog houses. NH₃₍g₎ removal: a novel approach was developed to reduce ammonia emissions from CAFOs in general, and poultry houses in particular. Air sucked by the dedicated air capturing system from close to the litter was shown to have NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. The NH₃₍g₎ rich waste air was conveyed to an acidic (0<pH<~5) bubble column reactor where NH₃ was converted to NH₄⁺. The reactor operated in batch mode, starting at pH 0 and was switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurred, at pH ~5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency was practically 100% throughout the process as long as the face velocity was below 4 cm/s. The potential advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. H₂S₍g₎ removal: The main goal of this part was to develop a specific treatment process for minimizing H₂S₍g₎ emissions from hog houses. The proposed process consists of three units: In the 1ˢᵗ H₂S₍g₎ is absorbed into an acidic (pH<2) ferric iron solution and oxidized by Fe(III) to S⁰ in a bubble column reactor. In parallel, Fe(III) is reduced to Fe(II). In the 2ⁿᵈ unit Fe(II) is bio-oxidized back to Fe(III) by Acidithiobacillus ferrooxidans (AF).In the 3ʳᵈ unit S⁰ is separated from solution in a gravity settler. The work focused on three sub-processes: the kinetics of H₂S absorption into a ferric solution at low pH, the kinetics of Fe²⁺ oxidation by AF and the factors that affect ferric iron precipitation (a main obstacle for a continuous operation of the process) under the operational conditions. H₂S removal efficiency was found higher at a higher Fe(III) concentration and also higher for higher H₂S₍g₎ concentrations and lower flow rates of the treated air. The rate limiting step of the H₂S reactive absorption was found to be the chemical reaction rather than the transition from gas to liquid phase. H₂S₍g₎ removal efficiency of >95% was recorded with Fe(III) concentration of 9 g/L using typical AFO air compositions. The 2ⁿᵈ part of the work focused on kinetics of Fe(II) oxidation by AF. A new lab technique was developed for determining the kinetic equation and kinetic parameters (KS, Kₚ and mₘₐₓ) for the bacteria. The 3ʳᵈ part focused on iron oxide precipitation under the operational conditions. It was found that at lower pH (1.5) jarosite accumulation is slower and that the performance of the AF at this pH was sufficient for successive operation of the proposed process at the H₂S fluxes predicted from AFOs. A laboratory-scale test was carried out at Purdue University on the use of the integrated system for simultaneous hydrogen sulfide removal from a H₂S bubble column filled with ferric sulfate solution and biological regeneration of ferric ions in a packed column immobilized with enriched AFbacteria. Results demonstrated the technical feasibility of the integrated system for H₂S removal and simultaneous biological regeneration of Fe(III) for potential continuous treatment of H₂S released from CAFO. NH₃ and H₂S gradient measurements at egg layer and swine barns were conducted in winter and summer at Purdue. Results showed high potential to concentrate NH₃ and H₂S in hog buildings, and NH₃ in layer houses. H₂S emissions from layer houses were too low for a significant gradient. An NH₃ capturing system was designed and tested in a 100-chicken broiler room. Five bell-type collecting devices were installed over the litter to collect NH₃ emissions. While the air extraction system moved only 10% of the total room ventilation airflow rate, the fraction of total ammonia removed was 18%, because of the higher concentration air taken from near the litter. The system demonstrated the potential to reduce emissions from broiler facilities and to concentrate the NH₃ effluent for use in an emission control system. In summary, the project laid a solid foundation for the implementation of both processes, and also resulted in a significant scientific contribution related to AF kinetic studies and ferrous analytical measurements.
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