Chemistry Commons^™

Preface To The Memorial Special Issue For Professor Chuansin Cha, Xin-Ping Ai, Han-Xi Yang, Lin Zhuang, Sheng-Li Chen

Journal of Electrochemistry

No abstract provided.

Licoo2 As Sulfur Host To Enhance Cathode Volumetric Capacity For Lithium-Sulfur Battery, Lu Wang, Xue-Ping Gao

Journal of Electrochemistry

Lithium-sulfur battery is one of the most promising secondary battery systems due to its super high theoretical gravimetric and volumetric energy densities (2600 Wh·kg^-1 and 2800 Wh·L^-1, respectively). However, the practical volumetric capacity of sulfur cathode is still unsatisfied due to the overuse of low-density host materials, such as carbon nanomaterials. Herein, commercial LiCoO₂ with the high tap density of 2.94 g·cm^-3 was used as the host material to build high density sulfur-based composite and compact electrode for increasing the volumetric capacity. Obviously, the tap density of the as-prepared S/LiCoO₂ composite was 1.90 g·cm …

Research Progress Of Key Components In Lithium-Sulfur Batteries, Jia-Jia Chen, Quan-Feng Dong

Journal of Electrochemistry

Due to the much higher theoretical specific capacity and energy density than the ones of traditional lithium ion battery, Li-S batteries have long been at the pinnacle in the realms of high-energy Li-metal batteries. However, the complicated electrochemical reactions on the sulfur cathode and Li anode, induced by the thermodynamic and kinetic behaviors of lithium polysulfides, are the intrinsic bottleneck to realize the full potential of Li-S batteries for practical application. In this review, we firstly discuss the roles, and thermodynamic and kinetic behaviors of polysulfides in the charging and discharging processes of Li-S batteries. Then, the functional design and …

Fundamentals Of Distribution Of Relaxation Times For Electrochemical Impedance Spectroscopy, Jia Wang, Qiu-An Huang, Wei-Heng Li, Juan Wang, Quan-Chao Zhuang, Jiu-Jun Zhang

Journal of Electrochemistry

Electrochemical impedance spectroscopy (EIS) is a powerful electrochemical characterization technology, which has been widely used in the field of electrochemical energy, such as lithium-ion batteries, supercapacitors, fuel cells, etc. Distribution of relaxation time (DRT) is an EIS deconvolution technique which does not depend on the prior knowledge of the targeted research object. Furthermore, DRT can serve to separate and analyze physical and chemical processes which are highly overlapped in their EIS data. In order to encourage the application and popularization of DRT deconvolution technology, several core questions are addressed in this paper: (1) DRT deconvolution principle, implementation steps and important …

Research Progress Of Sulfur Cathode Catalytic Conversions For Lithium-Sulfur Batteries, Qin-Jun Shao, Jian Chen

Journal of Electrochemistry

The electrochemical reduction of sulfur (S) takes place through multistep reactions when S is used as a cathode material. The complete discharge of S to form final product lithium sulfide (Li₂S) is a two-electron reaction. The formation of low-order lithium polysulfides (LiPS) needs to overcome certain energy barriers. And the reduction of Li₂S₂ to Li₂S is the rate-limited step. The reaction kinetic of sulfur cathode is the critical key to determine the electrochemical performance of Li-S batteries, such as specific energy, specific power and low temperature performance, etc. Accelerating the rate-limited step kinetics …

Liquid Metal Electrodes For Electrochemical Energy Storage Technologies, Hao-Miao Li, Hao Zhou, Kang-Li Wang, Kai Jiang

Journal of Electrochemistry

Electrochemical energy storage technologies (ESTs) with low cost, long lifespan and high safety are of great importance for efficient integration of renewable energy into the grid. Liquid metal electrodes (LMEs) possessing the merits of high electronic conductivity, easy manufacture and amorphous structure is of great application value in the field of energy storage batteries. During charge-discharge processing, the LMEs could avoid the issues of structural deformation and dendrite growth in solid metal electrodes, which could effectively extend the cycle life of the LME based batteries. Moreover, LME based batteries are easy to be scaled up and less expensive, which are …

Delineating Heme-Mediated Versus Direct Protein Oxidation In Peroxidase-Activated Cytochrome, Victor Yin, Derek Holzscherer, Lars Konermann

Chemistry Publications

Oxidation of key residues in cytochrome c (cyt c) by chloramine T (CT) converts the protein from an electron transporter to a peroxidase. This peroxidase-activated state represents an important model system for exploring the early steps of apoptosis. CT-induced transformations include oxidation of the distal heme ligand Met80 (MetO, +16 Da) and carbonylation (LysCHO, -1 Da) in the range of Lys53/55/72/73. Remarkably, the 15 remaining Lys residues in cyt c are not susceptible to carbonylation. The cause of this unusual selectivity is unknown. Here we applied top-down mass spectrometry (MS) to examine whether CT-induced oxidation is catalyzed by heme. …

“Bottled” Spiro-Doubly Aromatic Trinuclear [Pd2ru]+ Complexes, Maksim Kulichenko, Nikita Fedik, Anna Monfredini, Alvaro Muñoz-Castro, Davide Balestri, Alexander I. Boldyrev, Giovanni Maestri

Chemistry and Biochemistry Faculty Publications

Following an ongoing interest in the study of transition metal complexes with exotic bonding networks, we report herein the synthesis of a family of heterobimetallic triangular clusters involving Ru and Pd atoms. These are the first examples of trinuclear complexes combining these nuclei. Structural and bonding analyses revealed both analogies and unexpected differences for these [Pd₂Ru]⁺ complexes compared to their parent [Pd₃]⁺ peers. Noticeably, participation of the Ru atom in the π-aromaticity of the coordinated benzene ring makes the synthesized compound the second reported example of ‘bottled’ double aromaticity. This can also be referred …

Oxidation Of Phenolic Aldehydes By Ozone And Hydroxyl Radicals At The Air-Water Interface, Md Sohel Rana, Marcelo I. Guzman

Chemistry Faculty Publications

Biomass burning releases highly reactive methoxyphenols into the atmosphere, which can undergo heterogeneous oxidation and act as precursors for secondary organic aerosol (SOA) formation. Understanding the reactivity of such methoxyphenols at the air–water interface is a matter of major atmospheric interest. Online electrospray ionization mass spectrometry (OESI-MS) is used here to study the oxidation of two methoxyphenols among three phenolic aldehydes, 4-hydroxybenzaldehyde, vanillin, and syringaldehyde, on the surface of water. The OESI-MS results together with cyclic voltammetry measurements at variable pH are integrated into a mechanism describing the heterogeneous oxidative processing of methoxyphenols by gaseous ozone (O₃) and …

Competition Between Solvent-Solvent And Solvent-Solute Interactions In The Microhydration Of The Hexafluorophosphate Anion, Pf6⁻(H2o)N=1,2, Yasmeen A. Abdo, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

This study systematically examines the interactions of the hexafluorophosphate anion (PF₆^-) with one or two solvent water molecules (PF₆^-(H₂O)n where n = 1, 2). Full geometry optimizations and subsequent harmonic vibrational frequency computations are performed on each stationary point using a variety of common density functional theory methods (B3LYP, B3LYP-D3, M06-2X, and ωB97XD) and the MP2 and CCSD(T) ab initio methods with a triple-ζ correlation consistent basis set augmented with diffuse functions on all non-hydrogen atoms (cc-pVTZ for H and aug-cc-pVTZ for P, O, and F; denoted as haTZ). Five new stationary …

Synthesis, In Vitro, And In Vivo Evaluation Of Novel N-Phenylindazolyl Diarylureas As Potential Anti-Cancer Agents., Lucas N Solano, Grady L Nelson, Conor T Ronayne, Shirisha Jonnalagadda, Sravan K Jonnalagadda, Kaija Kottke, Robert Chitren, Joseph L Johnson, Manoj K Pandey, Subash C. Jonnalagadda, Venkatram R Mereddy

College of Science & Mathematics Departmental Research

Novel N-phenylindazole based diarylureas have been designed, synthesized and evaluated as potential anticancer agents. In vitro cell viability studies of these derivatives illustrate good potency with IC50 values in the range of 0.4–50 μM in several cancer cell lines including murine metastatic breast cancer 4T1, murine glioblastoma GL261, human triple negative breast cancer MDA-MB-231, human pancreatic cancer MIAPaCa-2, and human colorectal cancer cell line WiDr. The ester group in the lead compound 8i was modified to incorporate amino-amides to increase solubility and stability while retaining biological activity. Further in vitro studies reveal that lead candidates inhibit tube length in HUVEC …

A Sandwich-Type Cluster Containing Ge@Pd3 Planar Fragment Flanked By Aromatic Nonagermanide Caps, Hong-Lei Xu, Nikolay V. Tkachenko, Zi-Chuan Wang, Wei-Xing Chen, Lei Qiao, Alvaro Muñoz-Castro, Alexander I. Boldyrev, Zhong-Ming Sun

Chemistry and Biochemistry Faculty Publications

Sandwich-type clusters with the planar fragment containing a heterometallic sheet have remained elusive. In this work, we introduce the [K(2,2,2-crypt)]₄{(Ge₉)₂[η⁶-Ge(PdPPh₃)₃]} complex that contains a heterometallic sandwich fragment. The title compound is structurally characterized by means of single-crystal X-ray diffraction, which reveals the presence of an unusual heteroatomic metal planar fragment Ge@Pd₃. The planar fragment contains a rare formal zerovalent germanium core and a peculiar bonding mode of sp²-Ge@(PdPPh₃)₃ trigonal planar structure, whereas the nonagermanide fragments act as capping ligands. The …

Free-Radical-Mediated Glycan Isomer Differentiation, Rayan Murtada, Kimberly Fabijanczuk, Kaylee Gaspar, Xueming Dong, Kawthar Zeyad Alzarieni, Kimberly Calix, Edgar Manriquez, Rose Mery Bakestani, Hilkka I. Kenttämaa, Jinshan Gao

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The inherent structural complexity and diversity of glycans pose a major analytical challenge to their structural analysis. Radical chemistry has gained considerable momentum in the field of mass spectrometric biomolecule analysis, including proteomics, glycomics, and lipidomics. Herein, seven isomeric disaccharides and two isomeric tetrasaccharides with subtle structural differences are distinguished rapidly and accurately via one-step radical-induced dissociation. The free-radical-activated glycan-sequencing reagent (FRAGS) selectively conjugates to the unique reducing terminus of glycans in which a localized nascent free radical is generated upon collisional activation and simultaneously induces glycan fragmentation. Higher-energy collisional dissociation (HCD) and collision-induced dissociation (CID) are employed to provide …

Antimicrobial Photodynamic Activity Of Gallium‐Substituted Haemoglobin On Silver Nanoparticles, Ana V. Morales‐De‐Echegaray, Lu Lin, Badhu Sivasubramaniam, Aiga Yermembetova, Qi Wang, Nader S. Abutaleb, Mohamed N. Seleem, Alexander Wei

Department of Chemistry Faculty Publications

Methicillin-resistant Staphylococcus aureus (MRSA), a major scourge in skin and soft-tissue infections, expresses surface-bound haemoprotein receptors that can be exploited for the targeted delivery of photosensitizers. We have developed a nanosized agent for targeted antimicrobial photodynamic therapy (aPDT), comprised of GaPpIX (a hemin analog with potent photosensitizer activity) encapsulated in haemoglobin (GaHb), mounted on 10 nm Ag nanoparticles (AgNPs). The average GaHb-AgNP contains 28 GaPpIX units stabilized by Hb αβ-dimer units. Eradication (>6-log reduction) of S. aureus and MRSA can be achieved by a 10-second exposure to 405 nm irradiation from a light-emitting diode (LED) array (140 mW cm−2), …

Countercurrent Actinide Lanthanide Separation Process (Alsep) Demonstration Test With A Simulated Purex Raffinate In Centrifugal Contactors On The Laboratory Scale, Andreas Wilden, Fabian Kreft, Dimitri Schneider, Zaina Paparigas, Giuseppe Modolo, Gregg J. Lumetta, Artem V. Gelis, Jack D. Law, Andreas Geist

Chemistry and Biochemistry Faculty Research

An Actinide Lanthanide Separation Process (ALSEP) for the separation of trivalent actinides (An(III)) from simulated raffinate solution was successfully demonstrated using a 32-stage 1 cm annular centrifugal contactor setup. The ALSEP solvent was composed of a mixture of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and N,N,N′,N′-tetra-(2-ethylhexyl)-diglycolamide (T2EHDGA) in n-dodecane. Flowsheet calculations and evaluation of the results were done using the Argonne’s Model for Universal Solvent Extraction (AMUSE) code using single-stage distribution data. The co-extraction of Zr(IV) and Pd(II) was prevented using CDTA (trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid) as a masking agent in the feed. For the scrubbing of co-extracted Mo; citrate-buffered acetohydroxamic acid was …

Graphene-Based Electrochemical Aptasensor For The Detection Of Salmonella Typhimurium, Shalini Muniandy

Student Works (2020-2029)

Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid and sensitive detection of foodborne pathogens. The emergence of electrochemical aptasensor which is a compact analytical device with a combination of an aptamer as the biorecognition element integrated on the transducer surface created a breakthrough in the detection of foodborne bacterial pathogens. Graphene has emerged as a promising nanomaterial for reliable detection of pathogenic bacteria due to its exceptional properties such as high electrical conductivity, large surface to volume ratio, high mechanical strength and its unique interactions with DNA bases of …

Mutational Analysis Confirms The Presence Of Distal Inhibitor-Selectivity Determining Residues In B. Stearothermophilus Dihydrofolate Reductase, Tyler Eck, Seema Patel, Thomas Candela, Katherine Leon H, Michael Little, Natalia E. Reis, Uththara Liyanagunawardana, Ueli Gubler, Cheryl A. Janson, Jaclyn Catalano, Nina M. Goodey

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Many antibacterial and antiparasitic drugs work by competitively inhibiting dihydrofolate reductase (DHFR), a vital enzyme in folate metabolism. The interactions between inhibitors and DHFR active site residues are known in many homologs but the contributions from distal residues are less understood. Identifying distal residues that aid in inhibitor binding can improve targeted drug development programs by accounting for distant influences that may be less conserved and subject to frequent resistance causing mutations. Previously, a novel, homology-based, computational approach that mines ligand inhibition data was used to predict residues involved in inhibitor selectivity in the DHFR family. Expectedly, some inhibitor selectivity …

High-Temperature Resistant Water-Soluble Polymers Derived From Exotic Amino Acids, Sumant Dwivedi, Aniruddha Nag, Shigeki Sakamoto, Yasuyoshi Funahashi, Toyohiro Harimoto, Kenji Takada, Tatsuo Kaneko

Faculty Publications

© The Royal Society of Chemistry. High-performance water-soluble polymers have a wide range of applications from engineering materials to biomedical plastics. However, existing materials are either natural polymers that lack high thermostability or rigid synthetic polymers. Therefore, we design an amino acid-derived building block, 4,4′-diamino-α-truxillate dianion (4ATA²⁻), that induces water solubility in high-performance polymers. Polyimides containing 4ATA²⁻ units are intrinsically water-soluble and are processed into films cast from an aqueous solution. The resulting polyimide films exhibit exceptional transparency and extremely high thermal stability. In addition, the films can be made insoluble in water by simple post-treatment using …

Design, Synthesis Of Axial Chiral Triazole, Jing Wang

USF Tampa Graduate Theses and Dissertations

This thesis contains three parts: 1) The briefly review of chiral P, N-ligands. 2) The summary of triazole as ligands. 3) The attempt of designing, synthesizing the chiral triazole ligands.

In the first part, we have reviewed all the major P, N-ligands in the history, including how they were synthesized and resolved into single enantiomer. We also used some examples to show their utility potential in different reactions.

In the second part, we summarized the triazole ligands which mainly developed by our group including their structures, their potential and utility in different types of chemical reactions.

In the last part, …

Transesterification Of Poly(Ethyl Glyoxylate): A Route To Structurally Diverse Polyglyoxylates, Rebecca E. Yardley, Amir Rabiee Kenaree, Xiaoli Liang, Elizabeth R. Gillies

Chemistry Publications

Polyglyoxylates are a class of self-immolative polymers that depolymerize in solution and the solid state. The glyoxylic acid degradation product is a metabolite in the glyoxylate cycle and can also be processed in the liver in humans, making polyglyoxylates attractive for applications in the environment and in medicine. Although expanding the scope of available polyglyoxylates would enable new properties and applications, highly pure glyoxylate monomers are required for polymerization, and this level of purity is difficult to achieve for many potential monomers. To address this challenge, we report here the 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-catalyzed post-polymerization transesterification of poly(ethyl glyoxylate) (PEtG) as a …

Theoretical Studies And Rational Design Of Symmetrical And Unsymmetrical Squarine Dyes: An Application For Dye-Sensitized Solar Cell, Ameerul Hazeeq Hashim

Student Works (2020-2029)

Dye- sensitized solar cell (DSSC) has been explored in depth due to its effectiveness and low-cost conversion of photovoltaic energy. Squarine has unique properties because it has the capacity to increase light-harvesting energy as well as its low-cost conversion of photo-energy. Dyes that perform well, namely the symmetrical indolenine-based squaraine dye (SQM1a, VG1, and VG10) and the unsymmetrical indolenine-based squaraine dye (SQM1b, SQ01, MSQ, and VG13) were computationally studied and modified. Six density functionals were used to verify the accuracy of the simulation ranging from generalized gradient approximation (pure-GGA) density functional to the large Hartree-Fock exchange functional. Three methods were …

Optical Properties And Composition Of Viscous Organic Particles Found In The Southern Great Plains, Matthew Fraund, Daniel Bonanno, Swarup China, Don Q. Pham, Daniel Veghte, Johannes Weis, Gourihar Kulkarni, Ken Teske, Mary K. Gilles, Alexander Laskin, Ryan C. Moffet

Department of Chemistry Student Articles

Atmospheric high-viscosity organic particles (HVOPs) were observed in samples of ambient aerosols collected in April and May 2016 in the Southern Great Plains of the United States. These particles were apportioned as either airborne soil organic particles (ASOPs) or tar balls (TBs) from biomass burning based on spetro-microscopic imaging and assessments of meteorological records of smoke and precipitation data. Regardless of their apportionment, the number fractions of HVOPs were positively correlated (R2=0.85) with increased values of absorption Ångström exponent (AAE) measured in situ for ambient aerosol at the site. Extending this correlation to 100 % HVOPs yields an …

Soft Ion Sputtering Of Pani Studied By Xps, Afm, Tof-Sims, And Sts, Christopher M. Goodwin, Zachary E. Voras, Xiao Tong, Thomas P. Beebe, Jr.

Chemistry Faculty Publications

Herein is a study of the soft sputtering method, gas cluster ion sputtering (GCIS), and its effects on the atomic, morphologic, and band structure properties of polyaniline (PAni) as studied with X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry, atomic force microscopy, and scanning tunneling spectroscopy (STS). The GCIS source used was a 1000 argon atom cluster with 4 keV energy, which resulted in a sputter yield of 3.4 ± 0.2 × 10−3 nm3 per argon atom. Soft ion sputtering reduced the sample by explicitly removing the oxidized contaminants as determined by surface sensitive techniques: XPS and Time-of-flight secondary …

Chemical Synthesis Of Homogeneous Human E-Cadherin N-Linked Glycopeptides: Stereoselective Convergent Glycosylation And Chemoselective Solid-Phase Aspartylation, Chen Zeng, Bin Sun, Xuefeng Cao, Joshua Zhu, Olawale Micheal Oluwadahunsi, Ding Liu, He Zhu, Jiabin Zhang, Qing Zhang, Gaolan Zhang, Christopher Andrew Gibbons, Yunpeng Liu, Jun Zhou, Peng George Wang

Faculty Work Comprehensive List

We report herein an efficient chemical synthesis of homogeneous human E-cadherin N-linked glycopeptides consisting of a heptapeptide sequence adjacent to the Asn-633 N-glycosylation site with representative N-glycan structures, including a conserved trisaccharide, a core-fucosylated tetrasaccharide, and a complex-type biantennary octasaccharide. The key steps are a chemoselective on-resin aspartylation using a pseudoproline-containing peptide and stereoselective glycosylation using glycosyl fluororide as a donor. This synthetic strategy demonstrates potential utility in accessing a wide range of homogeneous N-linked glycopeptides for the examination of their biological function.

Optimization Of Cation Exchange Chromatography Purification Of A Small Peptide: An Industrial And Practical Approach, Jamin Willoughby

Honors Theses

Ion exchange chromatography (IEX) is a common chemical separation technique that is used to separate ionizable target molecules from a liquid mixture mobile phase by adsorption of the molecule to a stationary phase. In chromatography, the stationary phase is a porous solid that the target molecule and mobile phase flows through, and is commonly referred to as the resin. Resins are commonly packed into hollow cylindrical columns. The mobile phase is the liquid solvent which flows through the column containing the stationary phase. The target molecule will have an affinity for the resin and adsorb to it, while impurities in …

The Efficient Synthesis Of D-Xylulose And Formal Synthesis Of Syringolide 1, Sudhakar Kalagara, Gabriel Orozco, Shizue Mito

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Wittig reaction and asymmetric dihydroxylation were used as the key steps in the synthesis of D-xylulose, a commercially available but costly carbohydrate. The effects of protecting groups and reactions conditions on asymmetric dihydroxylation are demonstrated. Optically pure D-xylulose was obtained after 4-6 steps from readily available hydroxyacetone and ethylene glycol. The method also involves some other valuable intermediates along the synthesis. Those intermediates were applied in the formal synthesis of Syringolides. A key precursor butenolide to Syringolide 1, the first non-proteinaceous specific elicitors of plant hypersensitive response, was obtained after 3 steps from the intermediate (8–10 steps from hydroxyacetone and …

Modular Synthesis And Transition Metal-Free Alkynylation/Alkenylation Of Castagnoli–Cushmanderived N,O- And N,S-Heterocyclic Vinyl Chlorides, Timothy K. Beng, Abdikani Omar Farah, Victoria Shearer

All Faculty Scholarship for the College of the Sciences

A modular and functional group-tolerant protocol for the transition metal-free coupling of novel N,O- and N,S-heterocyclic vinyl chlorides with terminal acetylenes and styrenes has been developed, leading to the epimerization-free synthesis of fully carbofunctionalized dihydro-1,4-oxazines/thiazines. Bicyclic morpholines have also been prepared through the interrogation of newly synthesized cross-conjugated dienes in Diels–Alder reactions. The use of environmentally benign reaction media endows the current strategy with a practical advantage.

Cosore: A Community Database For Continuous Soil Respiration And Other Soil-Atmosphere Greenhouse Gas Flux Data, Ben Bond-Lamberty, Danielle S. Christianson, Avni Malhotra, Stephanie C. Pennington, Debjani Sihi, Amir Aghakouchak, Hassan Anjileli, M. Altaf Arain, Juan J. Armesto, Samaneh Ashraf, Mioko Ataka, Dennis Baldocchi, Thomas Andrew Black, Nina Buchmann, Mariah S. Carbone, Shih-Chieh Chang, Patrick Crill, Peter S. Curtis, Eric A. Davidson, Ankur R. Desai, John E. Drake, Tarek S. El-Madany, Michael Gavazzi, Carolyn-Monika Görres, Christopher M. Gough, Michael Goulden, Jillian Gregg, Omar Gutiérrez Del Arroyo, Jin-Sheng He, Takashi Hirano, Anya Hopple, Holly Hughes, Järvi Järveoja, Rachhpal Jassal, Jinshi Jian, Haiming Kan, Jason Kaye, Yuji Kominami, Naishen Liang, David Lipson, Catriona A. Macdonald, Kadmiel Maseyk, Kayla Mathes, Marguerite Mauritz, Melanie A. Mayes, Steve Mcnulty, Guofang Miao, Mirco Migliavacca, Scott Miller, Chelcy F. Miniat, Jennifer G. Nietz, Mats B. Nilsson, Asko Noormets, Hamidreza Norouzi, Christine S. O'Connell, Bruce Osborne, Cecilio Oyonarte, Zhuo Pang, Matthias Peichl, Elise Pendall, Jorge F. Perez-Quezada, Claire L. Phillips, Richard P. Phillips, James W. Raich, Alexandre A. Renchon, Nadine K. Ruehr, Enrique P. Sánchez-Cañete, Matthew Saunders, Kathleen E. Savage, Marion Schrumpf, Russell L. Scott, Ulli Seibt, Whendee L. Silver, Wu Sun, Daphne Szutu, Kentaro Takagi, Masahiro Takagi, Munemasa Teramoto, Mark G. Tjoelker, Susan Trumbore, Masahito Ueyama, Rodrigo Vargas, Ruth K. Varner, Joseph Verfaillie, Christoph Vogel, Jinsong Wang, Greg Winston, Tana E. Wood, Juying Wu, Thomas Wutzler, Jiye Zeng, Tianshan Zha, Quan Zhang, Junliang Zou

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil-to-atmosphere CO₂ flux, commonly though imprecisely termed soil respiration (R_S), is one of the largest carbon fluxes in the Earth system. An increasing number of high-frequency R_S measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems …

A Fuzzy Assessment Model For Hospitals Services Quality Based On Patient Experience, Mohamed Khodyer Alkafaji, Eman Salih Al-Shamery

Karbala International Journal of Modern Science

The patient's experience is a lens for services assessment that provide from healthcare institutions because the patient is the first and the last recipient for the service. The patient's experience carries a lot of uncertainty and an ultimate decision cannot be taken from the patient about the services, but it carries the partial truth. Many artificial intelligence technologies deal with the concept of partial truth, such as genetic algorithms and neural networks, but the fuzzy logic remains pioneering to deal with uncertainty. This paper aims to develop an assessment model by using fuzzy inference that is able to assess the …

A Laser Induced Fluorescence Design For Renewable Energy Application, Shaimaa S. Mahdi, Intisar A. Hamad

Karbala International Journal of Modern Science

Biomass is considered to be one of the highest potential renewable energy sources to meet the requirements of energy in the world, where it can be used as an effective alternative for renewable energy sources, including electricity and heating, as well as fuel used in transport. One of the most common problems accompanying the usage of biomass through gasification processes to produce gases is the amounts of undesirable formed Tars. In this paper, a Laser Induced Fluorescence spectroscopy (LIF) method was incorporated to identify the produced Tar compounds at high temperature in the gasification technology. The effect of tars deposition …