Chemistry Commons^™

Gas Permeability Of Polydimethylsiloxane Membranes Lled With Clinoptilolite Indifferent Cationic Forms, Çi̇ğdem Atalay-Oral

Turkish Journal of Chemistry

Zeolite-polymer mixed matrix membranes were prepared by lling polydimethylsiloxane (PDMS) with clinop- tilolite in various cationic forms of K, Mg, H, and Na. The membranes were characterized by scanning electron microscopy as well as measurements of O$_{2}, $N$_{2}$ and CO$_{2}$ gas permeabilities. The results indicated the presence of an optimum zeolite loading in the mixed matrix membranes maximizing permeability. The type of the cationic form of clinoptilolite used affected the permeabilities and ideal selectivities of the zeolite-polymer mixed matrix membranes investigated to some degree and some improvements were obtained when compared to the ideal selectivities of the original polymeric membranes.

Experimental And Theoretical Studies Of Carbazole-Based Schiff Base As A Fluorescent Fe$^{3+}$ Probe, Hakan Kandemi̇r, Abdulkadi̇r Koçak, Süreyya Oğuz Tümay, Bünyemi̇n Çoşut, Yunus Zorlu, İbrahi̇m Fazil Şengül

Turkish Journal of Chemistry

Synthesis of a new (E)-N1-((9-ethyl-9H-carbazol-3-yl)methylene)-5-nitrobenzene-1,2-diamine as a fluorescent chemosensor for selective detection of Fe$^{3+}$ ion over a number of other metal ions is described. The method for the synthesis of the carbazole Schiff base was based on the condensation of carbazole-3-carbaldehyde with 4-nitro-o-phenyldiamine in dimethylformamide in a moderate yield. The structure of the final compound was characterized by $^{1}$H NMR, $^{13}$C NMR, IR, mass spectrometry, and single crystal X-ray diffraction. The final compound exhibited exceptional selective and sensitive turn-on fluorescence response to the Fe$^{3+}$ cation. The fluorescent intensity of the final compound was increased 20-fold and the stoichiometry ratio of …

Simultaneous Determination Of Copper(Ii) And Zinc(Ii) Via Simple Acid-Base Titrimetry Using Glass Ph Electrode, Emi̇ne Gül Cansu Ergün, Adnan Kenar

Turkish Journal of Chemistry

The combination of potentiometric methods with multivariate calibration techniques allows complex mixtures to be analyzed. In this study, a new method was developed and reported for simultaneous determination of copper(II) and zinc(II) cations in a mixture by titrimetric methods. The developed method permits simultaneous cation analysis with low detection limits, just by using a pH electrode. This work has achieved the challenging goal of developing a cost-effective and applicable method that can be applied in most laboratories due to independence of any chemical instruments. Partial least squares 1, one of the multivariate calibration techniques, was used in the analysis of …

Synthesis And Characterization Of New Thiophene--Benzimidazole-Based Electrochromes, Emi̇ne Gül Cansu Ergün

Turkish Journal of Chemistry

In the present study, two new donor--acceptor--donor-type molecules were synthesized and the electro-optical properties of the resulting monomers and their corresponding polymers were investigated. Thiophene was selected as the donor unit and cycloheptyl- and cyclooctyl- substituted benzimidazoles were used as the acceptor units. The synthesized monomers and their electrochemically obtained polymers were characterized using cyclic voltammetry and UV-Vis spectrometry. The optical band gap values of the polymers were 1.62 eV and the polymer films changed color to gray upon oxidation, while they were brick red in their neutral states. Moreover, changing the ring size on the acceptor group from seven …

Adsorptive Properties Of Mesoporous Silica Modified With Lewis Base Molecule And Its Application In The Preconcentration Of Cu(Ii), Co(Ii), And Cd(Ii) From Aqueous Media, Janaíne Do Rócio Ivassechen, Alexandre De Oliveira Jorgetto, Marcos Henrique Pereira Wondracek, Adrielli Cristina Peres Da Silva, Luiz Fabrício Zara, Valber De Albuquerque Pedrosa, Bruno Prior Rocha, Margarida Juri Saeki, Gustavo Rocha Castro

Turkish Journal of Chemistry

Cocondensation and postfunctionalization methods were employed to synthesize a mesoporous silica with large surface area (795.1 $\pm $ 1.1 m$^{2}$ g$^{-1})$ modified with 4-amino-5-hydrazino-1,2,4-triazole-3-thiol, which was successfully applied to adsorb and preconcentrate Cu(II), Co(II), and Cd(II) from aqueous media. Infrared spectroscopy of the adsorbent material demonstrated N-H stretching bonds related to primary amines existing in the ligand molecule, elemental analysis revealed the presence of 0.132 mmol g$^{-1}$ of nitrogen, scanning electron microscopy indicated globularly shaped particles with average size of 10 $\mu $m, and the point of zero charge was found to be 7.2. Kinetic data were applied to the …

Photocatalytic Degradation Of The Herbicide Quinclorac In Water Using Mn (Iii) Salen And Solar Light, Yisi Yang, Yan Zhang, Qingru Zeng

Turkish Journal of Chemistry

Quinclorac (QNC) is a widely used herbicide and is persistent in surface and ground waters. Its residuals and converted products are hazardous to aquatic animals, vegetation, and microbes, and it is therefore important to degrade QNC using an efficient and environmental friendly technology. In this study, the photocatalytical degradation of QNC using [(R,R)-(N,N$'$-bis(3,5,3$'$,5$'$-tetra-tert-butylsalicylidene)-1,2-cyclohexanediaminato] manganese(III) acetate (Mn (III) salen) and H$_{2}$O$_{2}$ was performed under natural sunlight irradiation and a 91% degradation rate was achieved in neutral pure water in 240 min. The identified degradation products confirmed that the cleavage of QNC molecules was the main process involved in the hydroxylation, along …

One-Pot Synthesis Of Substituted 4$H$-Chromenes By Nickel Ferrite Nanoparticles As An Efficient And Magnetically Reusable Catalyst, Hamideh Ahankar, Ali Ramazani, Katararzyna Slepokura, Tadeusz Lis, Sang Woo Joo

Turkish Journal of Chemistry

Nickel ferrite magnetic nanoparticles (NiFe$_{2}$O$_{4}$ MNPs) were prepared via the autocombustion assisted sol-gel method. The efficient catalyst was investigated by FT-IR, XRD, ICP, SEM, and TEM techniques. A one-pot, three-component reaction is reported for the synthesis of substituted 4$H$-chromenes in the presence of NiFe$_{2}$O$_{4}$ MNPs as a reusable catalyst in a green solvent at 40 $^{\circ}$C under clean, efficient, and mild conditions. Furthermore, selected products were characterized by FT-IR, $^{1}$H NMR, and $^{13}$C NMR. The single-crystal X-ray analysis of product 4u was also conclusively confirmed. Easy workup procedure, high purity of products via simple recrystallization, and environmentally benign conditions are …

Environmental Impact Assessment Of Natural Radioactivity And Heavy Metals In Drinking Water Around Akkuyu Nuclear Power Plant In Mersin Province, Gürsel Karahan, Hali̇m Taşkin, Nesli̇ Bi̇ngöldağ, Eni̇s Kapdan, Yusuf Zi̇ya Yilmaz

Turkish Journal of Chemistry

The aim of this study was to determine natural radioactive and heavy element concentrations in Mersin drinking water samples before the commissioning of the Akkuyu nuclear power plant and to collect data for possible environmental contaminations in the future. Drinking water samples were taken from the provincial center, districts, and populated villages. The annual effective dose of natural radionuclides and cancer risks were calculated for each person living in the city. Hazard index and cancer risk were calculated, which were caused by heavy elements. Mean gross alpha and beta radioactivity concentrations in drinking water were 0.059 Bq/L and 0.120 Bq/L, …

Optimizing The Coagulation/Flocculation Process For Bentonite Suspension With Poly(Acrylamide-Co-(N-Methyl-4-Vinylpyridinium Tosylate, Brahim Bouras, Tayeb Hocine, Kamel Ismet Benabadji, Karim Benhabib, Ali Mansri

Turkish Journal of Chemistry

In this work, we are interested in the quaternization of poly(acrylamide-co-4-vinylpyridine) [AM7/VP10/0.1%/] by the methyl-tosylate CH$_{3}$TS. The obtained copolymer poly(acrylamide-co-(N-methyl-4-vinylpyridinium tosylate)) [AM7/VP10/0.1%/CTs] has been characterized by $^{1}$H NMR and UV-Vis spectroscopy. The macromolecular weight was determined by size exclusion chromatography as well as by viscosity. With the aim of removing turbidity by coagulation-flocculation from bentonite suspensions, the prepared copolymer was used as a flocculant. Several important parameters in the flocculation process, such as pH of water, initial turbidity, and flocculant concentration, were utilized for the optimization of wastewater treatment. Flocculation experiments were carried out in a conventional jar test where …

A Simple Automated Microplate Method For Determining Reducing Sugars In Food Extracts And Synthetic Serum Using Cupric-Neocuproine As Reductant, Mustafa Bener, Esi̇n Akyüz, Furkan Burak Şen, Kevser Sözgen Başkan, Esma Tütem, Mustafa Reşat Apak

Turkish Journal of Chemistry

In the present work, a simple automated microplate method based on cupric ion reduction is described for determining total reducing sugars in food extracts and synthetic serum. The reaction of Cu(II)-Nc (cupric-neocuproine) with reducing sugars was performed in alkaline medium in microplates, and the absorbance of the formed highly colored Cu(I)-Nc chelate in a plate reader at 450 nm was recorded. The proposed method was applied to reducing sugars (glucose, fructose, galactose, maltose, and lactose) and their linear calibration curves were constructed. The detection and quantification limits (LOD and LOQ) for glucose were 0.14 and 0.46 $\mu $M, respectively. Absorbances …

Voltammetric Determination Of Phenmedipham Herbicide Using A Multiwalled Carbon Nanotube Paste Electrode, Ersi̇n Demi̇r, Recai̇ İnam

Turkish Journal of Chemistry

Phenmedipham is an herbicide used especially in the sugar beet harvest to fight against broad-leaved weeds and studies of its voltammetric behavior and detection have not been done before. The superior properties of carbon nanotubes such as electrical conductivity, mechanical strength, and wide potential ranges make them attractive for chemical sensors and the phenmedipham compound gave an oxidation peak at $+$1320 mV (vs. Ag/AgCl) on the nanostructured multiwalled carbon nanotube paste electrode. Square wave voltammetric measurements recorded for phenmedipham showed that the peak current increased linearly between 0.02 and 2.0 mg/L with a regression coefficient of $r$ = 0.9989, and …

A Novel One-Pot And Rapid Synthesis Of Polyfunctionalized Benzo[A]Pyrimido[5',4':5,6] Pyrido[2,3-C]Phenazine Derivatives Under Microwave Irradiation, Mahdieh Tabibian, Razieh Mohebat, Masoumeh Tabatabaee

Turkish Journal of Chemistry

A one-pot, environmentally friendly, and efficient protocol for the synthesis of novel polyfunctionalized benzo[$a$]pyrimido[5',4':5,6]pyrido[2,3-$c$]phenazine derivatives has been reported by a one-pot, four-component sequential reaction between 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamines, benzaldehydes, and 6-amino-1,3-dimethyluracil in the presence of $p$-TSA as a nontoxic, inexpensive, ecofriendly, and efficacious solid acid catalyst. Two C-C bonds, two C=N bonds, and one C-N bond, as well as two new rings, were formed in this reaction. Through this procedure, compounds with substantial biological and pharmaceutical properties are generated in a single operation. Factors such as high yields, less reaction time, operational simplicity, and lack of any dangerous reagents/solvents have made …

The Synthesis Of New 3,4-(Bisaryl)-1,8-Naphthalimide And 2,3-(Bisaryl)-7$H$-Benzimidazo[2,1-A]Benzo[D]Isoquinolin-7-One Compounds And An Investigation Of Their Photochromic Properties, Ersi̇n Orhan, Mahmut Köse, Tolga Yazan

Turkish Journal of Chemistry

Three new photochromic compounds, 3-(2,5-dimethyl-3-thienyl)-4-(2-phenyl-5-methyl-4-thiazolyl)-1,8-napht- halimide (1-O), 2,3-bis(2-phenyl-5-methyl-4-thiazolyl)-7$H$-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (2-O), and 2,5-dimethyl-3-thienyl)-7$H$-benzimidazo[2,1-a]benzo[de]isoquinolin-7-one (3-O), were synthesized and their photochromic properties were studied. Compound 1-O was synthesized by two consecutive Suzuki coupling reactions using 2,5-dimethylthiophene-3-boronic acid and 5-methyl-2-phenylthiazole-4-boronic acid. Photochromic compounds 2-O and 3-O were prepared by multistep reactions starting with 3-iodo-4-bromo-1,8-naphthalic anhydride and 2,5-dimethylthiophene-3-boronic acid or 2-phenyl-5-methylthiazole-4-boronic acid. All photochromic compounds showed a color change from colorless (or light yellow) to blue-green, purple, or orange colors (depending on the nature of the structures) on exposure to UV light at 365 nm in ethyl acetate solutions. The colored solutions can be reversed to …

Experimental And Theoretical Studies On Cis-Dioxomolybdenum(Vi) Complexes Of Onn-Donor~Thiosemicarbazone, Berat İlhan Ceylan, Ayberk Yilmaz, Olcay Bölükbaşi Yalçinkaya, Bahri̇ Ülküseven

Turkish Journal of Chemistry

Cis-dioxomolybdenum(VI) chelate complexes with 5-chloro-2-hydroxybenzophenone S-methyl-4-phenylthiose- micarbazone (L) were synthesized in the general formula (MoO$_{2}$(L)D), where D is an odd- or even-numbered alcohol (methanol (1), ethanol (2), n-propanol (3), n-butanol (4), and allyl alcohol (5)). The structures of 1-5 were verified by elemental analysis, Fourier transform infrared (FT-IR), and $^{1}$H NMR spectra. Complex 5 crystallizes in the monoclinic space group P21/n, and its crystalline data showed a dimeric structure formed by a pair of intermolecular hydrogen bonds with 1.92 Å. These dimers are stacked in a similar crystalline structure as a single molecule. The experimental data were compared with the …

Effect Of Ph On The Complexation Of Irbesartan With $\Beta $-, Hydroxypropyl-$\Beta $-, And $\Gamma $-Cyclodextrin: Solubility Enhancement And Physicochemical Characterization, Fakhri Yousef

Turkish Journal of Chemistry

The affinity of irbesartan (IRB) to form inclusion complexes with $\beta $-cyclodextrin ($\beta $-CD), hydroxypropyl-$\beta $-cyclodextrin (HP-$\beta $-CD), and $\gamma $-cyclodextrin ($\gamma $-CD) was investigated in aqueous buffered solutions at pH 1.7, 4.1, and 7.0. Analysis of the UV absorption-pH profiles revealed that IRB has two p$K_{a}$ values: p$K_{a1\, }=$ 3.60 (imidazolinone ring moiety) and p$K_{a2\, }=$ 4.70 (tetrazole moiety). In the presence of 5.0 mmol L$^{-1} \beta $-CD, the tetrazole moiety became more acidic, indicating its inclusion within the $\beta $-CD cavity. Phase-solubility diagrams (PSDs) were obtained for IRB in aqueous buffered solutions of $\beta $-CD, HP-$\beta $-CD, and …

A Model To Predict Concentrations And Uncertainty For Mercury Species In Lakes, Ashley Hendricks

Dissertations, Master's Theses and Master's Reports

To increase understanding of mercury cycling, a seasonal mass balance model was developed to predict mercury concentrations in lakes and fish. Results indicate that seasonality in mercury cycling is significant and is important for a northern latitude lake. Models, when validated, have the potential to be used as an alternative to measurements; models are relatively inexpensive and are not as time intensive. Previously published mercury models have neglected to perform a thorough validation. Model validation allows for regulators to be able to make more informed, confident decisions when using models in water quality management. It is critical to quantify uncertainty; …

Fabrication Of Superhydrophobic Gold Film On Polymer Substrates, Siriwan Boonmeewiriya

Chulalongkorn University Theses and Dissertations (Chula ETD)

Superhydrophobic surface was fabricated by a reduction reaction between chloroauric acid (HAuCl4) and sodium formate (HCOONa) on polydimethylsiloxane (PDMS) substrate without any further surface modification. This generated gold films with superhydrophobic properties examined by water contact angle (WCA) and contact angle hysteresis measurement. Wettability of the fabricated gold film on PDMS substrate can be controlled by the deposition time which provides the WCA > 160o and it could be up to 164.41o with a contact angle hysteresis of 1.93o when the deposition time was prolonged at least 2 hours. To propose the deposition mechanism, the morphological structure and chemical characters of …

Enhanced Hot Electron Lifetimes In Quantum Wells With Inhibited Phonon Coupling, Hamidreza Esmaielpour, Vincent R. Whiteside, Herath P. Piyathilaka, Sangeetha Vijeyaragunathan, Bin Wang, Echo Adcock-Smith, Kenneth P. Roberts, Tetsuya D. Mishima, Michael B. Santos, Alan D. Bristow, Ian R. Sellers

Faculty & Staff Scholarship

Hot electrons established by the absorption of high-energy photons typically thermalize on a picosecond time scale in a semiconductor, dissipating energy via various phonon-mediated relaxation pathways. Here it is shown that a strong hot carrier distribution can be produced using a type-II quantum well structure. In such systems it is shown that the dominant hot carrier thermalization process is limited by the radiative recombination lifetime of electrons with reduced wavefunction overlap with holes. It is proposed that the subsequent reabsorption of acoustic and optical phonons is facilitated by a mismatch in phonon dispersions at the InAs-AlAsSb interface and serves to …

Determination Of Sugar In Non-Alcoholic Beverages Using Near Infrared Spectroscopy Combined With Chemometrics, Sureerat Makmuang

Chulalongkorn University Theses and Dissertations (Chula ETD)

The measurement of Near infrared (NIR) spectroscopy, combined with chemometric techniques, has been widely employed for quality control in food products. This study presents a methodology to optimize the calibration models, called "universal model" of NIR spectra of primary condition (glucose solutions) and maintain the accurate prediction of secondary conditions. For instance, the models were designed for determination of glucose concentration in non-alcoholic drinks. Three stages of methodology including pre-processing, feature selection and main component extraction were applied to spectral data in order to obtain the universal calibration model. The simulated NIR spectra with different noise levels were used to …

Energetics And Vibrational Signatures Of Nucleobase Argyrophilic Interactions, Suhwan Paul Lee

Honors Theses

This study investigates the interactions of both purine (adenine and guanine) and pyrimidine (cytosine, thymine, and uracil) nucleobases with a pair of silver atoms (Ag2). Full geometry optimizations were performed on several structures of each nucleobase/Ag2 complex and the corresponding isolated monomers using the M06-2X density functional theory (DFT) method with a correlation consistent triple-ζ basis set augmented with diffuse functions on all atoms and a relativistic pseudopotential on Ag (aug-cc-pVTZ for H, C, N, and O and aug-cc-pVTZ-PP for Ag; denoted aVTZ). Harmonic vibrational frequency computations indicate that each optimized structure corresponds to a minimum on the M06-2X/aVTZ potential …

O-Glcnac Post Translational Modification Of Hypoxia-Inducible Factor (Hif) Proteins, Hailey Elisabeth Grisham

Honors Theses

O-linked β-N-acetylglucosamine (O-GlcNAc) post-translational modification (O- GlcNAcylation), plays a vital role in many metabolic pathways, including those of numerous diseases. New research methods and basic functional roles of O-GlcNAc post- translational modification on metabolism, human health, and cancer are quickly developing, but a vast amount of research remains on the specificity of this pathway towards specific proteins. In this study, T47D breast cancer cells were used as an in vitro model to investigate the effects of O-GlcNAc modification on hypoxia-inducible factor (HIF) proteins.

Investigation Of Vibrational Signatures Of Nitrobenzenes Enhanced By Argyrophilic Interactions, Hailey Reed

Honors Theses

This investigation studies the interactions between various nitroaromatic high energy density materials (HEDMs) and a pair of silver atoms (Ag2). Additionally, we examine the changes in frequency, infrared (IR) intensities, and Raman activities induced by the Ag2 unit as the complexes form. Full geometry optimizations of the isolated HEDM molecules as well as complexes where Ag2 is bound to various argyrophillic sites of these compounds have been carried out along with the corresponding harmonic vibrational frequency computations using the M06-2X density functional with a correlation consistent triple-ζ basis set augmented with diffuse functions on all atoms and a relativistic pseudopotential …

Cell-Free Telomere Dna As A Biomarker For Treatment Response And Tumor Burden In Glioblastoma, John P. North

Honors Theses

Telomeres are repeated nucleotide sequences that cap the ends of each chromosome in eukaryotes. Telomeres are among the earliest genomic sequences to be degraded during apoptosis, potentially providing a biomarker of cell death. To study this, we quantified telomeres in serum from Glioblastoma and non-cancer patients. Cell-free DNA was isolated by centrifugation to remove intact cells, and purified using a QIAamp DNA Blood Midi Kit (Qiagen). Cell-free telomeric (cf-tel) and cell-free actin (cf-actin) DNA were analyzed with quantitative PCR. Total cell-free DNA was measured with PicoGreen assays. We hypothesize that patients with Glioblastoma tumors have higher cf-tel DNA levels than …

Purification Protocol Development And Analysis Of Binding Properties Of Calmodulin Collagen-Like Protein, Patrick P. Boddie

Honors Theses

Calmodulin is an intensely studied, intracellular, calcium-binding protein that is involved in diverse physiological processes. When bound to calcium, calmodulin undergoes a conformational change that allows it to bind specific target peptides with high affinity, one being the calmodulin binding region of myosin light chain kinase, herein called M13. This high affinity, calcium dependent association has made it a desirable choice for use in a biomaterial for drug delivery for non-steroidal anti- inflammatory drugs (NSAIDs). Two artificial genes have been designed by our lab for use in the proposed biomaterial: calmodulin collagen-like protein (CCLP), a construct composed of two calmodulin …

Connecting Chemistry To Community With Deliberative Democracy, Regis Komperda, Jack Barbera, Erin Shortlidge, Gwen Shusterman, Stem Education And Equity Institute, Portland State University

Biology Faculty Publications and Presentations

Science education communities have called for rethinking curricula to improve student understanding of the nature of science and the role of science in addressing controversial modern issues such as climate change, energy policy, and pollution levels. One approach to meeting this call is integrating these topics into class activities that require students to use discussion and scientific approaches to solve problems and deliberate potential policy solutions. Deliberative democracy (DD) is one such active learning approach in which students work in peer groups to reach a consensus on a scientific topic relevant to both real-world issues and course content. During DD …

Effect Of Curing Rate On The Microstructure And Macroscopic Properties Of Epoxy Fiberglass Composites, Ammar Patel, Olesksandr Kravchenko, Ica Manas-Zloczower

Mechanical & Aerospace Engineering Faculty Publications

Curing rates of an epoxy amine system were varied via different curing cycles, and glass-fiber epoxy composites were prepared using the same protocol, with the aim of investigating the correlation between microstructure and composite properties. It was found that the fast curing cycle resulted in a non-homogenous network, with a larger percentage of a softer phase. Homogenized composite properties, namely storage modulus and quasi-static intra-laminar shear strength, remained unaffected by the change in resin microstructure. However, fatigue tests revealed a significant reduction in fatigue life for composites cured at fast curing rates, while composites with curing cycles that allowed a …

Mls Measurements Of Stratospheric Hydrogen Cyanide During The 2015-2016 El Niño Event, Hugh C. Pumphrey, Norbert Glatthor, Peter F. Bernath, Christopher D. Boone, James W. Hannigan, Ivan Ortega, Nathaniel J. Livesey, William G. Read

Chemistry & Biochemistry Faculty Publications

It is known from ground-based measurements made during the 1982-1983 and 1997-1998 El Niño events that atmospheric hydrogen cyanide (HCN) tends to be higher during such years than at other times. The Microwave Limb Sounder (MLS) on the Aura satellite has been measuring HCN mixing ratios since launch in 2004; the measurements are ongoing at the time of writing. The winter of 2015- 2016 saw the largest El Niño event since 1997-1998. We present MLS measurements of HCN in the lower stratosphere for the Aura mission to date, comparing the 2015- 2016 El Niño period to the rest of the …

Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Background

Biochar cation exchange capacity (CEC) is a key property that is central to biochar environmental applications including the retention of soil nutrients in soil amendment and removal of certain pollutants in water-filtration applications.

Results

This study reports an innovative biochar-ozonization process that dramatically increases the CEC value of biochars by a factor of 2. The ozonized biochars also show great improvement on adsorption of methylene blue by as much as a factor of about 5. In this study, biochar samples treated with and without ozone were analyzed by means of pH and CEC assays, water field capacity measurement, elemental …

Stratospheric Ozone And Hcl Trends (2000-2016): How Significant Is Recent Growth In Chlorinated Very Short-Lived Substances, Ryan Hossaini, Martyn Chipperfield, Peter Bernath, Anton Fernando, Sandip Dhomse, Wuhu Feng

Chemistry & Biochemistry Faculty Publications

[Introduction] Chlorinated very short-lived substances (VSLS), such as dichloromethane (CH₂CL₂), chloroform (CHCl₃₎ and perchloroethylene (C₂Cl₄) constitute a small, but growing source of stratospheric chlorine (e.g. WMO, 2014). High-altitude aircraft observations provide some constraint on the stratospheric source gas injection of chlorine from these compounds, though product gas injection - from VSLS-derived phosgene and HCl produced in the troposphere - is uncertain. Furthermore, in addition to an overall paucity of atmospheric VSLS observations, the impact of VSLS growth on stratospheric composition trends in the recent past (e.g. ozone, HCl) remains poorly constrained.

Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky

Chemistry & Biochemistry Faculty Publications

Room temperature NH₃ absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm^-1 and 17,950 - 18,250 cm^-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …