Chemistry Commons^™

Investigation Of The Twist Of A Yarn With A Square Structure, Liza Toreniyazova, R. Orazbayeva, D. Kadirova, R. Rakhimkhodzhaev

Karakalpak Scientific Journal

The article presents the results of a study of the effect of yarn twist on the surface density of clothing fabrics with a square structure and the filling calculation of the fabric depending on the weave. The tension in the process of weaving square fabric on a loom with short overlaps is higher relative to weaving of fabric with long overlaps. With an increase in the twist of the yarn, the surface density of the fabric, the coefficient of filling (CST) and the coefficient of connectivity of the fabric (FTC) of the square structure increase.

Current Transportation Processes In P-N-N+ - Structures Under Saturation Of Recombination Rate, Abat K. Uteniyazov, A Leyderman, M Nsanbaev, Sh Annayeva

Karakalpak Scientific Journal

In the article, the model of the recombination of non - equilibrium carriers through a pair recombination complex of the donor-acceptor pair type is studied under conditions when the concentration of such paired complexes changes (decreases) during the excitation of the material. Also, the article describes that the injection into the p-n-n⁺ - structure can lead to fundamental changes in the distribution of the concentration of free carriers, especially, to the appearance of a periodic term depending on the concentration of the sample length (instead of the usual exponential dependence).

Evaluation Of Log P, Pka, And Log D Predictions From The Sampl7 Blind Challenge, Teresa Danielle Bergazin, Nicolas Tielker, Yingying Zhang, Junjun Mao, M. R. Gunner, Karol Francisco, Carlo Ballatore, Stefan M. Kast, David L. Mobley

Publications and Research

The Statistical Assessment of Modeling of Proteins and Ligands (SAMPL) challenges focuses the computational modeling community on areas in need of improvement for rational drug design. The SAMPL7 physical property challenge dealt with prediction of octanol-water partition coefficients and pK_a for 22 compounds. The dataset was composed of a series of N-acylsulfonamides and related bioisosteres. 17 research groups participated in the log P challenge, submitting 33 blind submissions total. For the pK_a challenge, 7 different groups participated, submitting 9 blind submissions in total. Overall, the accuracy of octanol-water log P predictions in the SAMPL7 challenge was …

Recovery Of High Specific Activity Molybdenum-99 From Accelerator-Induced Fission On Low-Enriched Uranium For Technetium-99m Generators, M. Alex Brown, Nathan Johnson, Artem V. Gelis, Milan Stika, Anna G. Servis, Alex Bakken, Christine Krizmanich, Kristin Shannon, Peter Kozak, Amanda Barnhart, Chad Denbrock, Nicolas Luciani, Terry Grimm, Peter Tkac

Chemistry and Biochemistry Faculty Research

A new process was developed to recover high specific activity (no carrier added) 99Mo from electron-accelerator irradiated U3O8 or uranyl sulfate targets. The process leverages a novel solvent extraction scheme to recover Mo using di(2-ethylhexyl) phosphoric acid following uranium and transuranics removal with tri-n-butyl phosphate. An anion-exchange concentration column step provides a final purification, generating pure 99Mo intended for making 99Mo/99mTc generators. The process was demonstrated with irradiated uranium targets resulting in more than 95% 99Mo recovery and without presence of fission products or actinides in the product.

Characterizing The Vibrational Spectra Of Hydrogen Bonded Systems With Molecular Dynamics Simulations And Quantum Chemical Methods, Dalton Boutwell

Master of Science in Chemical Sciences Theses

We apply and assess the utility of DMD for the purpose of investigating complex spectral features in N₂H⁺···OC, N₂D⁺···OC, C₂O₄H^-, C₂O₄D^- and (HCOOH)₂. The proton transfer as a vibrational motion consists of diffuse qualities that can be accounted for with classical and quantum chemical analyses. Classical approaches yield a wealth of information about vibrational spectra at a reduced cost, as in the case of previously investigated N₄H⁺. The isoelectronic N₂H⁺···OC has …

Mathematical Model For Measuring The Concentration Of Nanoparticles In A Liquid During Sedimentation, Safaa Mohammed Ridha Hussien Hussien, Airat Sakhabutdinov, Vladimir Anfinogentov, Maxim Danilaev, Vladimir Kuklin, Oleg Morozov

Karbala International Journal of Modern Science

Expanding the application areas of polymer composite materials with dispersed filler requires the development of technologies providing the required mechanical characteristics. One of these methods is based on forming a thin polymer shell on the surfaces of particles. At the same time, it is impossible to take into account the mechanical characteristics of a thin polymer shell due to its ultra-small thickness. The mechanical properties of the polymer shell can be determined only by indirect methods, and prior information can improve the adequacy of the properties determination. The method, which allows reducing the requirements for composite sample preparation, is proposed. …

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Β -Technetium: An Allotrope With A Nonstandard Volume-Pressure Relationship, Emily Siska, Dean Smith, Christian Childs, Daniel Koury, Paul M. Forster, Keith V. Lawler, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

We report the synthesis and structure of the second allotrope of technetium, β-Tc. Transformative pathways are accessed at extreme conditions using the laser-heated diamond anvil cell and confirmed with in situ synchrotron x-ray diffraction and Raman spectroscopy. β-Tc is fully recoverable to ambient conditions, although counter to our DFT calculations predicting a face-centered-cubic lattice, we observe a tetragonal structure (I4/mmm) that exhibits further tetragonal distortion with pressure. β-Tc has an expanded volume relative to the hcp ground state phase, that when doped with nitrogen has an unexpected volume lowering. Such anomalous behavior is possibly indicative of a rare electronic phase …

Engineered Nanostructured Nitrogen-Doped Carbon Network (Ndc) Electrodes With Unprecedented Cycling Stability For Water Capacitive Deionization In Harsh Conditions, Soha Essam Anwar

Theses and Dissertations

Capacitive deionization (CDI) is a feasible low-cost desalination technique for low-to-medium (brackish) salinity water. However, cycling stability and regeneration of the CDI electrodes are the bottlenecks hindering the practical application of the technology on large scale. Oxidation of the electrodes during the sequential adsorption-desorption processes is one of the most challenging problems hindering their long-term cycling performance. Herein, we demonstrated the ability to design and fabricate exceptionally stable CDI electrodes via a one-pot pyrolysis protocol. The optimized pyrolysis of nitrogen-carbon precursors at different temperatures enabled the fabrication of carbon materials with a controlled amount nitrogen dopant (NDCs) with exceptional cycling …

Complexes With Atomic Gold Ions: Efficient Bisligand Formation, Felix Duensing, Elisabeth Gruber, Paul Martini, Marcelo Goulart, Michael Gatchell, Bilal Rasul, Olof E. Echt, Fabio Zappa, Masoomeh Mahmoodi-Darian, Paul Scheier

Faculty Publications

Complexes of atomic gold with a variety of ligands have been formed by passing helium nanodroplets (HNDs) through two pickup cells containing gold vapor and the vapor of another dopant, namely a rare gas, diatomic molecule (H₂, N₂, O₂, I₂, P₂), or various polyatomic molecules (H₂O, CO₂, SF₆, C₆H₆, adamantane, imidazole, di-cyclopentadiene, and fullerene). The doped HNDs were irradiated by electrons; ensuing cations were identified in a high-resolution mass spectrometer. Anions were detected for benzene, di-cyclopentadiene, and fullerene. For most …

Colossal Density-Driven Resistance Response In The Negative Charge Transfer Insulator Mns2, Dylan Durkee, Nathan Dasenbrock-Gammon, G. Alexander Smith, Elliot Snider, Dean Smith, Christian Childs, Simon A.J. Kimber, Keith V. Lawler, Ranga P. Dias, Ashkan Salamat

Chemistry and Biochemistry Faculty Research

A reversible density driven insulator to metal to insulator transition in high-spin MnS2 is experimentally observed, leading with a colossal electrical resistance drop of 108 ω by 12 GPa. Density functional theory simulations reveal the metallization to be unexpectedly driven by previously unoccupied S22- σ3p∗ antibonding states crossing the Fermi level. This is a unique variant of the charge transfer insulator to metal transition for negative charge transfer insulators having anions with an unsaturated valence. By 36 GPa the emergence of the low-spin insulating arsenopyrite (P21/c) is confirmed, and the bulk metallicity is broken with the system returning to an …

Quantum Transport Of The 2d Surface State In A Nonsymmorphic Semimetal, Xue Liu, Jin Hu, Jiang Wei, Chunlei Yue, Sergey V. Erohin, Yanglin Zhu, Abin Joshy, Jinyu Liu, Ana M. Sanchez, David Graf, Pavel B. Sorokin, Zinqiang Mao

Physics Faculty Publications and Presentations

In a topological semimetal with Dirac or Weyl points, the bulk-boundary correspondence principle predicts a gapless edge mode if the essential symmetry is still preserved at the surface. The detection of such topological surface state has been considered as the fingerprint prove for crystals with nontrivial topological bulk band. On the contrary, it has been proposed that even with symmetry broken at the surface, a new surface band can emerge in nonsymmorphic topological semimetals. The symmetry reduction at the surface lifts the bulk band degeneracies and produces an unusual “floating” surface band with trivial topology. Here, we first report quantum …

College Of Natural Sciences Newsletter, June 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 6.

Page 1 Dean's Message
Page 2-6 Remembering the Life of Dr. Pengra and Celebrating His legacy for Entire Generations to Come.

Analysis And Comparison Of Optical Performance And Collectible Solar Energy Between Multi-Sectioned Compound Parabolic Concentrator (Cpc) And Restricted Exit Angle Cpc, Damasen Ikwaba Paul

Tanzania Journal of Science

This study was conducted to analyse and compare the optical performance and collectible solar radiation energy of two different Compound Parabolic Concentrators (CPCs): multi-sectioned CPC (hereafter called M-CPC) and restricted exit angle CPC (hereafter called R-CPC) so as to ascertain the best CPC for photovoltaics applications. For easy comparison between M-CPC and R-CPC, a standard CPC (hereafter called S-CPC) was also designed. A detailed ray trace simulation analysis was undertaken to compare ray trace diagrams, angular acceptance, optical efficiency and energy flux distribution of the three CPCs. Results indicated that the angular acceptance and optical efficiency of the three CPCs …

A Theoretical Study Of Synchronous Proton Transfer In (Hf)N, (H2O) N, And (Hcl) N Where N = 3, 4, 5, Johnny Yang

Honors Theses

For (HF)_n, (H₂O)_n, and (HCl)_n (n = 3 − 5), we have rigorously characterized the structures for the minima and transition states for synchronous proton transfer (SPT) with the CCSD(T) method and aug-cc-pVTZ basis set. The electronic barrier heights (∆E^†) associated with these transition states have also been computed with the explicitly correlated CCSD(T)-F12 method and the aug-cc-pVQZ-F12 basis set (abbreviated aQZ-F12). (HCl)_n (n = 3 − 5) SPT transition states have not been previously identified to the best of our knowledge, and they have been found …

Electrochemical And Spectroscopic Characterization Of Cerium Salts And Nanoceria Material, Emily Velarde, Wei Zhou

Symposium of Student Scholars

The nanoscale form of cerium oxide, nanoceria (nano-CeO_x), has drawn great attention in recent years in electrochemical, nanomaterial research and medicinal studies due to its antibacterial properties, UV absorption, and its biochemical function as possible radical scavenger. Many new synthesis methods have achieved uniform and biocompatible nanoceria particles, and our lab has created cerium oxide particles that shows UV/Vis. absorption and X-ray patterns similar to the commercial nanoceria and nanoceria made in other research laboratories with novel synthetic methods.

This study focuses on charactering and comparing electrochemical properties of cerium inorganic salts and synthesized nanoceria. Preliminary results …

Photochemistry Of Nh2No2 And Implications For Chemistry In The Atmosphere, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Recent studies have indicated that nitramide (NH₂NO₂) may be formed more plentifully in the atmosphere than previously thought, while also being a missing source of the greenhouse gas nitrous oxide (N₂O) via catalyzed isomerization. To validate the importance of NH₂NO₂ in the Earth’s atmosphere, the ground and first electronic excited states of NH₂NO₂ were characterized and its photochemistry was investigated using multireference and coupled cluster methods. NH₂NO₂ is non-planar and of singlet multiplicity in the ground state while exhibiting large out-of-plane rotation in the triplet …

Data-Driven Approaches To Complex Materials: Applications To Amorphous Solids, Dil Kumar Limbu

Dissertations

While conventional approaches to materials modeling made significant contributions and advanced our understanding of materials properties in the past decades, these approaches often cannot be applied to disordered materials (e.g., glasses) for which accurate total-energy functionals or forces are either not available or it is infeasible to employ due to computational complexities associated with modeling disordered solids in the absence of translational symmetry. In this dissertation, a number of information-driven probabilistic methods were developed for the structural determination of a range of materials including disordered solids to transition metal clusters. The ground-state structures of transition-metal clusters of iron, nickel, and …

College Of Natural Sciences Newsletter, May 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 5.

Page 1 Dean's Message
Page 2 - 3 Awards & Recognition
Page 4 Research Spotlight: Dr. Xiaoyang Zhang
Page 5 Upcoming Retirements
Page 6 - 7 Geography Alumni Social, Recent Media Coverage
Page 8 Open PRAIRIE Data
Page 9 - 11 Spring 2021 Dean's List and Academic Recognitions

Photothermal Response Induced By Nanocage-Coated Artificial Extracellular Matrix Promotes Neural Stem Cell Differentiation, Seunghyun Jung, Nathaniel Harris, Isabelle I. Niyonshuti, Samir V. Jenkins, Abdallah M. Hayar, Fumiya Watanabe, Azemat Jamshidi-Parsian, Jingyi Chen, Michael J. Borrelli, Robert J. Griffin

Mechanical Engineering Faculty Publications and Presentations

Strategies to increase the proportion of neural stem cells that differentiate into neurons are vital for therapy of neurodegenerative disorders. In vitro, the extracellular matrix composition and topography have been found to be important factors in stem cell differentiation. We have developed a novel artificial extracellular matrix (aECM) formed by attaching gold nanocages (AuNCs) to glass coverslips. After culturing rat neural stem cells (rNSCs) on these gold nanocage-coated surfaces (AuNC-aECMs), we observed that 44.6% of rNSCs differentiated into neurons compared to only 27.9% for cells grown on laminin-coated glass coverslips. We applied laser irradiation to the AuNC-aECMs to introduce precise …

Modeling The Problem Of Integral Geometry On A Family Of Hyperbolic And Spherical Curves, Azamat Pirimbetov, N. Uteuliev, G. Djaykov

Karakalpak Scientific Journal

The problems of integral geometry in a strip on a family of curves of hyperbolic and spherical type are considered which have numerous applications in problems of geophysics, thermoacoustic and photoacoustic tomography. Explicit formulas are obtained for the Fourier image of the solution of integral geometry problems in the class of smooth compactly supported functions. Further, the obtained formulas are investigated for stability using numerical methods. To solve the problems, algorithms are constructed. Numerical and graphical results of applying these algorithms to solving the problems are presented.

Sf6+: Stabilizing Transient Ions In Helium Nanodroplets, Simon Albertini, Stefan Bergmeister, Felix Laimer, Paul Martini, Elisabeth Gruber, Fabio Zappa, Milan Ončák, Paul Scheier, Olof E. Echt

Faculty Publications

There are myriads of ions that are deemed too short-lived to be experimentally accessible. One of them is SF₆⁺. It has never been observed, although not for lack of trying. We demonstrate that long-lived SF₆⁺ can be formed by doping charged helium nanodroplets (HNDs) with sulfur hexafluoride; excess helium is then gently stripped from the doped HNDs by collisions with helium gas. The ion is identified by high-resolution mass spectrometry (resolution m/Dm = 15000), the close agreement between the expected and observed yield of ions that contain minor sulfur isotopes, and collision-induced dissociation …

Direct Detection Of 5-Mev Protons By Flexible Organic Thin-Film Devices, Ilaria Fratelli, Andrea Ciavatti, Enrico Zanazzi, Laura Basiricò, Massimo Chiari, Laura Fabbri, John E. Anthony, Alberto Quaranta, Beatrice Fraboni

Chemistry Faculty Publications

The direct detection of 5-MeV protons by flexible organic detectors based on thin films is here demonstrated. The organic devices act as a solid-state detector, in which the energy released by the protons within the active layer of the sensor is converted into an electrical current. These sensors can quantitatively and reliably measure the dose of protons impinging on the sensor both in real time and in integration mode. This study shows how to detect and exploit the energy absorbed both by the organic semiconducting layer and by the plastic substrate, allowing to extrapolate information on the present and past …

Determination Of The Traits In Leguminous Crops Under Saline Condition, Tojiddin Kuliev, Karomat Ismailova

Karakalpak Scientific Journal

In this study, the variability and determination of genetic traits for winter legume crop varieties the Vostok-55 (Pisum arvense L) and Mirzachul-1 (Vicia villoza Roth L) were investigated under moderate saline soil condition. Results show that the weight of the bean was marked as variable and highly deterministic, and the height of the plants was the most stable. The selection of plants based on these traits is the most effective way of salinity. Both variety the forage pea Vostok-55 and vetch Mirzachul-1 is highly recommended as a sideration and forage crop in saline lands.

College Of Natural Sciences Newsletter, April 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 4

Page 1 Dean's Message
Page 2 & 3 Awards & Recognition
Page 4 Student Spotlight: Allsion Bjornstad
Page 5 Research Spotlight: Dr. Vondruska & Students
Page 6 Department Head Interviews
Page 7 Media Coverage of CNS
Page 8 Open PRAIRIE Data
Page 9 Student Club Spotlight: BMGSA
Page 10 Then & Now: Urban Geography

Food Security As A Factor Of Sustainable Development Of The Country, Timur Nurimbetov

Karakalpak Scientific Journal

The article examines the state of the food market and the trends in ensuring the country’s food security. The article also analyzes the regional characteristics of the agricultural products market in the Republic of Karakalpakstan. The saturation level of regional food markets has been studied. Scientific conclusions and practical recommendations on the supply of food to the population have been made.

Influence Of Laterial State Of Pair Impurity Complex On Recombination Processes In Semiconductors, L Yu Leyderman, R A. Ayukhanov, Abat Uteniyazov, E S. Esenbaeva, Sh X. Annayeva

Karakalpak Scientific Journal

The paper analyzes the question of the possible influence of the lateral state of a paired impurity complex on the recombination processes. It is shown that the lateral state of the paired impurity complex does not affect the recombination processes of nonequilibrium carriers - they go through that component of the impurity complex that exchanges carriers with both bands (in this particular case, through the component). The second component of the complex () can apparently play some role in the processes of carrier attachment.

Organization Of Compact Spinning Technology In Textile Clusters, Baxtiyar Aralbaevich Paluanov, Abdimalik Pirmatovich Pirmatov

Karakalpak Scientific Journal

The article proposes a system of continuous supply of raw cotton in continuous spinning technology and methods of maximizing the preservation of the natural properties of the fiber and obtaining high-quality yarn.

Pressure- And Temperature-Dependent Inelastic Neutron Scattering Study Of The Phase Transition And Phonon Lattice Dynamics In Para-Terphenyl, Qingan Cai, Michael Mcintire, Luke L. Daemen, Chen Li, Eric Chronister

Chemistry and Biochemistry Faculty Research

Inelastic neutron scattering has been performed on para-terphenyl at temperatures from 10 to 200 K and under pressures from the ambient pressure to 1.51 kbar. The temperature dependence of phonons, especially low-frequency librational bands, indicates strong anharmonic phonon dynamics. The pressure- and temperature-dependence of the phonon modes suggest a lack of phase transition in the region of 0-1.51 kbar and 10-30 K. Additionally, the overall lattice dynamics remains similar up to 200 K under the ambient pressure. The results suggest that the boundary between the ordered triclinic phase and the third solid phase, reported at lower temperatures and higher pressures, …

Alternative View Of Oxygen Reduction On Porous Carbon Electrocatalysts: The Substance Of Complex Oxygen-Surface Interactions, Giacomo De Falco, Marc Florent, Jacek Jagiello, Yongqiang Cheng, Luke L. Daemen, Anibal J. Ramirez-Cuesta, Teresa J. Bandosz

Publications and Research

Electrochemical oxygen reduction reaction (ORR) is an important energy-related process requiring alternative catalysts to expensive platinum-based ones. Although recently some advancements in carbon catalysts have been reported, there is still a lack of understanding which surface features might enhance their efficiency for ORR. Through a detailed study of oxygen adsorption on carbon molecular sieves and using inelastic neutron scattering, we demonstrated here that the extent of oxygen adsorption/interactions with surface is an important parameter affecting ORR. It was found that both the strength of O2 physical adsorption in small pores and its specific interactions with surface ether functionalities in the …