Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

City University of New York (CUNY)

2019

Discipline
Keyword
Publication
Publication Type
File Type

Articles 1 - 30 of 242

Full-Text Articles in Physical Sciences and Mathematics

Dark-Binding Process Relevant To Preventing Photosensitized Oxidation: Conformation-Dependent Light And Dark Mechanisms By A Dual-Functioning Diketone, Sarah J. Belh, Niluksha Walalawela, Stas Lekhtman, Alexander Greer Dec 2019

Dark-Binding Process Relevant To Preventing Photosensitized Oxidation: Conformation-Dependent Light And Dark Mechanisms By A Dual-Functioning Diketone, Sarah J. Belh, Niluksha Walalawela, Stas Lekhtman, Alexander Greer

Publications and Research

Few photosensitizers function in both light and dark processes as they usually have no function when the lights are turned off. We hypothesized that light and dark mechanisms in an α-diketone will be decoupled by dihedral rotation in a conformation- dependent binding process. Successful decoupling of these two functions is now shown. Namely, anti- and syn-skewed conformations of 4,4′-dimethylbenzil promote photosensitized alkoxy radical production, whereas the syn conformation promotes a binding shutoff reaction with trimethyl phosphite. Less rotation of the diketone is better suited to the photosensitizing function since phosphite binding arises through the syn conformer of lower stability. The …


The Rockaway Project - Townes, Diara Jepris D. Townes Dec 2019

The Rockaway Project - Townes, Diara Jepris D. Townes

Capstones

The Rockaway Project is a story-driven website that provides information on the government response to Superstorm Sandy recovery on the Rockaway peninsula in Queens, New York. Dozens of climate resiliency projects have been delayed or remain unfinished, despite millions of dollars in funding and six years of promises. The website hosts audio, visual and digital content, gathered through interviews and data collection.

Link to capstone project: https://www.youtube.com/watch?v=fAq2BeR4bS0&t=1s


Building Mof Nanocomposites With Oxidized Graphitic Carbon Nitride Nanospheres: The Effect Of Framework Geometry On The Structural Heterogeneity, Dimitrios A. Giannakoudakis, Teresa J. Bandosz Dec 2019

Building Mof Nanocomposites With Oxidized Graphitic Carbon Nitride Nanospheres: The Effect Of Framework Geometry On The Structural Heterogeneity, Dimitrios A. Giannakoudakis, Teresa J. Bandosz

Publications and Research

Composite of two MOFs, copper-based Cu-BTC (HKUST-1) and zirconium-based Zr-BDC (UiO-66), with oxidized graphitic carbon nitride nanospheres were synthesized. For comparison, pure MOFs were also obtained. The surface features were analyzed using x-ray diffraction (XRD), sorption of nitrogen, thermal analysis, and scanning electron microscopy (SEM). The incorporation of oxidized g-C3N4 to the Cu-BTC framework caused the formation of a heterogeneous material of a hierarchical pores structure, but a decreased surface area when compared to that of the parent MOF. In the case of UiO-66, functionalized nanospheres were acting as seeds around which the crystals grew. Even though the MOF phases …


Determinism Of Stochastic Processes Through The Relationship Between The Heat Equation And Random Walks, Gurmehar Singh Makker Dec 2019

Determinism Of Stochastic Processes Through The Relationship Between The Heat Equation And Random Walks, Gurmehar Singh Makker

Publications and Research

We study the deterministic characteristics of stochastic processes through investigation of random walks and the heat equation. The relationship is confirmed by discretizing the heat equation in time and space and determining the probability distribution function for random walks in dimension d = 1, 2. The existence of the relationship is presented both through theoretical analysis and numerical computation.


The Privacy Preserving Framework With Virtual Ring And Identity-Based Cryptography For Smart Grid, Leonard Sutanto Dec 2019

The Privacy Preserving Framework With Virtual Ring And Identity-Based Cryptography For Smart Grid, Leonard Sutanto

Publications and Research

One of the main challenges in the smart grid is how to efficiently manage the high-volume data from smart meters and sensors and preserve the privacy from the consumption data to avoid potential attacks (e.g., identity theft) for the involved prosumers, retail electricity providers and other clusters of distributed energy resources. This poster proposes a two-layer framework with the cloud computing infrastructure. The virtual ring and identity-based cryptography are utilized in each layer to preserve privacy efficiently. The methods of the virtual ring and identity-based cryptography are introduced. The purposes and needs are discussed at the end of this poster.


An Application Of The Ising Model, Juliano A. Everett Dec 2019

An Application Of The Ising Model, Juliano A. Everett

Publications and Research

Understanding how the Ising model works,what it represents, and how it can be applied to neurology. Given that an Ising model is an Entropy model that could be representative of the firing of neurons, some assumptions of the system are made and then the process is simulated through Monte Carlo methods.


Static Solid Relaxation Ordered Spectroscopy: Ss-Rosy, Gregory S. Boutis, Ravinath Kausik Nov 2019

Static Solid Relaxation Ordered Spectroscopy: Ss-Rosy, Gregory S. Boutis, Ravinath Kausik

Publications and Research

A two-dimensional pulse sequence is introduced for correlating nuclear magnetic resonance anisotropic chemical shifts to a relaxation time (e.g., T1) in solids under static conditions. The sequence begins with a preparatory stage for measuring relaxation times, and is followed by a multiple pulse sequence for homonuclear dipolar decoupling. Data analysis involves the use of Fourier transform, followed by a one-dimensional inverse Laplace transform for each frequency index. Experimental results acquired on solid samples demonstrate the general approach, and additional variations involving heteronuclear decoupling and magic angle spinning are discussed.


Graded Quivers, Generalized Dimer Models And Toric Geometry, Sebastián Franco, Azeem Hasan Nov 2019

Graded Quivers, Generalized Dimer Models And Toric Geometry, Sebastián Franco, Azeem Hasan

Publications and Research

The open string sector of the topological B-model on CY (m+2)-folds is described by m-graded quivers with superpotentials. This correspondence extends to general m the well known connection between CY (m+2)-folds and gauge theories on the world-volume of D(5-2m)-branes for m = 0, ..., 3. We introduce m-dimers, which fully encode the m-graded quivers and their superpotentials, in the case in which the CY (m+2)-folds are toric. Generalizing the well known m = 1,2 cases, m-dimers significantly simplify the connection between geometry and m-graded quivers. A key …


A Note On Graphs With Prescribed Orbit Structure, Abbe Mowshowitz, Matthias Dehmer, Frank Emmert-Streib Nov 2019

A Note On Graphs With Prescribed Orbit Structure, Abbe Mowshowitz, Matthias Dehmer, Frank Emmert-Streib

Publications and Research

No abstract provided.


Residential Household Yard Care Practices Along Urban-Exurban Gradients In Six Climatically-Diverse U.S. Metropolitan Areas, Dexter H. Locke, Colin Polsky, J. Morgan Grove, Peter M. Groffman, Kristen C. Nelson, Kelli L. Larson, Jeannine Cavender-Bares, James B. Heffernan, Rinku Roy Chowdhury, Sarah E. Hobbie, Neil D. Bettez, Sharon J. Hall, Christopher Neill, Laura Ogden, Jarlath O'Neil-Dunne Nov 2019

Residential Household Yard Care Practices Along Urban-Exurban Gradients In Six Climatically-Diverse U.S. Metropolitan Areas, Dexter H. Locke, Colin Polsky, J. Morgan Grove, Peter M. Groffman, Kristen C. Nelson, Kelli L. Larson, Jeannine Cavender-Bares, James B. Heffernan, Rinku Roy Chowdhury, Sarah E. Hobbie, Neil D. Bettez, Sharon J. Hall, Christopher Neill, Laura Ogden, Jarlath O'Neil-Dunne

Publications and Research

Residential land is expanding in the United States, and lawn now covers more area than the country’s leading irrigated crop by area. Given that lawns are widespread across diverse climatic regions and there is rising concern about the environmental impacts associated with their management, there is a clear need to understand the geographic variation, drivers, and outcomes of common yard care practices. We hypothesized that 1) income, age, and the number of neighbors known by name will be positively associated with the odds of having irrigated, fertilized, or applied pesticides in the last year, 2) irrigation, fertilization, and pesticide application …


Land Surface Temperature Variability Across India: A Remote Sensing Satellite Perspective, Satya Prakash, Hamidreza Norouzi Nov 2019

Land Surface Temperature Variability Across India: A Remote Sensing Satellite Perspective, Satya Prakash, Hamidreza Norouzi

Publications and Research

Land surface temperature (LST) plays a key role in the surface energy budget computation and land surface process studies. The Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard the Aqua and Terra satellites provide comprehensive global LST estimates at a fine spatial resolution. The MODIS products were recently upgraded to Collection 6, and shown to be more accurate than its predecessor Collection 5 products. In this study, LST and its variability have been examined across India from Collection 6 of the Aqua MODIS data at 0.05° spatial resolution for the period of 2003 to 2017. All-India mean LST characteristics show distinctive …


Planck's And Callendar's Blackbody Radiation Formulas And Their Fitness To Experimental Data, Max Tran Nov 2019

Planck's And Callendar's Blackbody Radiation Formulas And Their Fitness To Experimental Data, Max Tran

Publications and Research

In this paper, we compare the blackbody radiation density formula obtained with classical physics by Hugh L Callendar and the formula obtained by Max Planck using quantization of energy. We use R and Maxima to analyze their fitness on coordinating experimental data and indicate some limitations with experiments in this area.


From The Human To The Planetary: Speculative Futures Of Care, Miriam Ticktin Oct 2019

From The Human To The Planetary: Speculative Futures Of Care, Miriam Ticktin

Publications and Research

This is largely a theoretical, speculative essay that takes on the question of what ‘care’ looks like at a moment when climate change is increasingly taking center stage in public and political discussions. Starting with two new practices, namely, humanitarian care for nonhumans and One Health collaborations, I seek to determine what forms of political care can incorporate the well-being of future generations and future iterations of the earth. After an exploration of One Health as an approach to planetary care, I ask what its parts enable us to think, despite its limitations; I focus on the new human-nonhuman assemblages …


Evaluation Of Approaches For Mapping Tidal Wetlands Of The Chesapeake And Delaware Bays, Brian T. Lamb, Maria A. Tzortziou, Kyle C. Mcdonald Oct 2019

Evaluation Of Approaches For Mapping Tidal Wetlands Of The Chesapeake And Delaware Bays, Brian T. Lamb, Maria A. Tzortziou, Kyle C. Mcdonald

Publications and Research

The spatial extent and vegetation characteristics of tidal wetlands and their change are among the biggest unknowns and largest sources of uncertainty in modeling ecosystem processes and services at the land-ocean interface. Using a combination of moderate-high spatial resolution (


A Concise Workbook For College Algebra 2nd Edition, Fei Ye Oct 2019

A Concise Workbook For College Algebra 2nd Edition, Fei Ye

Open Educational Resources

This is the second edition of the book "A Concise Workbook for College Algebra". In this new edition, some tips and notes, more exercises and examples were added.


Tio2/S-Doped Carbons Hybrids: Analysis Of Their Interfacial And Surface Features, Teresa Bandosz, Alfonso Policicchio, Marc Florent, Po S. Poon, Juan Matos Oct 2019

Tio2/S-Doped Carbons Hybrids: Analysis Of Their Interfacial And Surface Features, Teresa Bandosz, Alfonso Policicchio, Marc Florent, Po S. Poon, Juan Matos

Publications and Research

Hybrids containing approximately equal amounts of P25 TiO2 and S-doped porous carbons were prepared using a water-based slurry mixing method. The materials were extensively characterized by adsorption of nitrogen, potentiometric titration, thermal analysis in air and in helium, XRD, XPS and SEM. The collected results showed the significant blockage of carbon micropores by TiO2 particles deposited on their outer surface. The formation of a new interface, especially for the S-rich samples, might also contribute to the porosity alteration. Analysis of surface chemistry suggested the presence of Ti-S bonds with an involvement of sulfur from thiophenic species in the carbon phase. …


Csci49379: Intro To Blockchain (Syllabus), Wendy Mock, Nyc Tech-In-Residence Corps Oct 2019

Csci49379: Intro To Blockchain (Syllabus), Wendy Mock, Nyc Tech-In-Residence Corps

Open Educational Resources

Syllabus for the course: CSCI 49397 - Blockchain. Delivered at Hunter College in Fall 2019 by Wendy Mock as part of the Tech-in-Residence Corps program.


Microwave Solventless Synthesis Of Meso-Tetrakis (Pentafluorophenyl)Poprphyrin (Tppf20) And Tris(Pentafluorophenyl))Corrole [Chemistry], Sunaina Singh Oct 2019

Microwave Solventless Synthesis Of Meso-Tetrakis (Pentafluorophenyl)Poprphyrin (Tppf20) And Tris(Pentafluorophenyl))Corrole [Chemistry], Sunaina Singh

Open Educational Resources

Organic chemistry is a two-semester course (Organic Chemistry I, SCC 251 and Organic Chemistry II, SCC 252) required for majors in Biology. The SCC 251 course has been designated for the Integrative Learning Core Competency as well the Digital Communication Ability. This course emphasizes the synthesis, structure, reactivity, and mechanisms of reaction of organic compounds. Laboratory stresses various organic synthetic and analytic techniques (distillation, extraction, chromatography and spectroscopy).

This lab provided an opportunity for students to go deeper with the chemistry content by correlating to the concepts they learned in General Chemistry courses such as Valence shell electron pair repulsion …


Titration Of A Newtown Creek Environmental Water Sample To Determine The Amount Of Chloride Ions [Chemistry], Kevin Mark Oct 2019

Titration Of A Newtown Creek Environmental Water Sample To Determine The Amount Of Chloride Ions [Chemistry], Kevin Mark

Open Educational Resources

Main Course Learning Objectives:

The General Chemistry 1 (SCC 201) course has multiple course learning objectives, which articulate key introductory chemistry concepts that all STEM students should possess. In particular, the Newtown Creek titration experiment aligns with SCC 201 learning objectives of:

  1. Demonstrate an appreciation of the role of chemistry in various aspects of life
  2. Perform basic laboratory skills such as the proper execution of titration techniques
  3. Describe and explain the fundamental chemistry concept of solution concentration
  4. Analyze and represent experimental data in tables and graphs, interpret experimental results and write laboratory reports

In the SCC 201 laboratory, students are …


Biophysics In Applications, Marilyn R. Gunner Oct 2019

Biophysics In Applications, Marilyn R. Gunner

Open Educational Resources

No abstract provided.


An Engineering Geological Anatomy Of The Padma River Bank Failure And Erosion, 2018: A Case Study Of Naria Bank Section, Bangladesh, Mir Fazlul Karim, Nazrul I. Khandaker, Shahidul Haque, M. Zillur Rahman, Muhammad Qumrul Hassan, Asm Maksud Kamal, Masud Ahmed, Belal A. Sayeed Sep 2019

An Engineering Geological Anatomy Of The Padma River Bank Failure And Erosion, 2018: A Case Study Of Naria Bank Section, Bangladesh, Mir Fazlul Karim, Nazrul I. Khandaker, Shahidul Haque, M. Zillur Rahman, Muhammad Qumrul Hassan, Asm Maksud Kamal, Masud Ahmed, Belal A. Sayeed

Publications and Research

The Naria town of Bangladesh is developed on the right bank of the Padma River. The bank is an old natural levee of Meghna River. The Holocene-Recent geology of Naria is actively dominated by the fluvial processes of Ganges-Brahmaputra-Meghna River system where the deltaic sediments are characterized as unconsolidated fine sand and silt, covered by thin veneer of clayey silt and loam. The annual volume of water discharge and flow dynamics are dependent on the intensity of the rainfall, runoff and the length of dry winter. Excessive river bank erosion, channel avulsion, renewed submergence of floodplains, and formation of natural …


Utilizing Dplot, Sedlog, And Arcgis Pro To Enhance Geologic Field Skills: Rosendale, Ulster County New York, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Leonardo Sanchez, Gugu Ginindza, Tyn Tyn Nai Sep 2019

Utilizing Dplot, Sedlog, And Arcgis Pro To Enhance Geologic Field Skills: Rosendale, Ulster County New York, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Leonardo Sanchez, Gugu Ginindza, Tyn Tyn Nai

Publications and Research

Capstone geologic field mapping courses in undergraduate geoscience programs aim to compliment the academic knowledge with technical field skills. As a pilot study, these tools were used to collect field data using folded lower Paleozoic to mid-Paleozoic sedimentary outcrops consisting of clastic, non-clastic and occasional mixed siliciclastics in Rosendale, Ulster County, New York. Rosendale is known for its classic geological outcrops with variable structural, stratigraphic, paleontological and sedimentological complexities – ideal for a field mapping course. Traditionally, students’ data acquisition in the field and its subsequent laboratory analysis to produce a final geologic field report utilized acetate overlays to produce …


Paleoenvironment Of The Devonian Fossiliferous Glenerie Limestone, Rosendale, Upstate New York, Gugu Ginindza, B'Jorn K. Forde, Sebastian R. Agustin, Nazrul I. Khandaker, Malek Shami, Stanley Schleifer Sep 2019

Paleoenvironment Of The Devonian Fossiliferous Glenerie Limestone, Rosendale, Upstate New York, Gugu Ginindza, B'Jorn K. Forde, Sebastian R. Agustin, Nazrul I. Khandaker, Malek Shami, Stanley Schleifer

Publications and Research

The Devonian Glenerie limestone outcrops throughout the Hudson Valley and is believed to correlate with the glauconite-rich Oriskany sandstone elsewhere in upstate New York. Field inspection of well-preserved outcrops in Rosendale, upstate New York, indicated the Glenerie formation to be composed of both thin and thickly-bedded chert, interbedded shale, and both calcareous to arenaceous limestone. The Glenerie formation is dominated by spirifer arenosis fossil, which is the index fossil for this formation. The goal of this research is to determine the conditions of the paleoenvironment prevalent to the deposition of the Glenerie formation. Within the arenaceous layers are the spirifer …


Positive Outcomes Of Involving Undergraduate And High School Students In Broader Aspect Of Earth System Science Through Peer Mentoring And Research Activities, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Juanpablo Rodriguez, Adacia Teemal, Krishna Mahabir, Michael Robinson, Ality Aghedo, Zachary A. Sanichar, Sol De Leon, Tamzid Mubin, Elton Selby Sep 2019

Positive Outcomes Of Involving Undergraduate And High School Students In Broader Aspect Of Earth System Science Through Peer Mentoring And Research Activities, Nazrul I. Khandaker, Shuayb Siddique, Matthew Khargie, Juanpablo Rodriguez, Adacia Teemal, Krishna Mahabir, Michael Robinson, Ality Aghedo, Zachary A. Sanichar, Sol De Leon, Tamzid Mubin, Elton Selby

Publications and Research

The importance of involving undergraduates and high school students in field-and-laboratory research investigations at an early stage through peer mentoring has been clearly demonstrated as a critical tool for essential training to fully comprehend academic content and a deeper understanding of the various STEM, geoscience-and- environmental science related topics. As far as we are concerned, student presenters/participants (over 1000) in our topical sessions since 2004 have always found face-to-face presentation through poster sessions to be an ideal scientific venue where exchange of knowledge and discussion are fruitful, constructive and encouraging. It is quite revealing to note that among the student …


Using Water Quality Index To Assess Groundwater Suitability At Gazipur District, Bangladesh, Muhammad Qumrul Hassan, Jowaher Raza, Mir F. Karim, Nazrul I. Khandaker Sep 2019

Using Water Quality Index To Assess Groundwater Suitability At Gazipur District, Bangladesh, Muhammad Qumrul Hassan, Jowaher Raza, Mir F. Karim, Nazrul I. Khandaker

Publications and Research

This study targeted to the suitability of groundwater for drinking purpose at Gazipur District undergoing rapid urbanization and increasing industrialization. The District has an area of 1741.53 km2, located in between 23°53' and 24°21' north latitudes and in between 90°09' and 92°39' east longitudes. From six Upazilas in Gazipur District, a total of 130 groundwater samples were collected, which are, Gazipur Sadar Upazila, Sreepur Upazila, Kaliakoir Upazila, Kapasia Upazila, and Kaligonj Upazila. A recent field observation review of industrial sludge found that heavy metal concentration was above the acceptable limit for agricultural soil. Gazipur being adjacent to Dhaka …


Amazon Alexa + Linked Open Data: Theorizing Concerning Relationships Between (Surveillant) Smart-Home Voice Assistants And Linked Open Data, Michelle Nitto Sep 2019

Amazon Alexa + Linked Open Data: Theorizing Concerning Relationships Between (Surveillant) Smart-Home Voice Assistants And Linked Open Data, Michelle Nitto

Publications and Research

No abstract provided.


Electrochemical Carbon Nanoprobes For Biological And Chemical System Studies, Keke Hu Sep 2019

Electrochemical Carbon Nanoprobes For Biological And Chemical System Studies, Keke Hu

Dissertations, Theses, and Capstone Projects

The progress in the field of nanoelectrochemistry requires preparation and characterization of nanometer scale electrochemical probes. The focus of my Ph.D. research was on development of carbon nanopipette-based electrodes with versatile and controllable geometry and their applications to nanoscale studies of chemical and biological systems. Carbon nanopipette (CNP) electrodes offer important advantages, including high sensitivity and improved analytical selectivity. They can serve as nanoreactors for sampling ultra-small solution volumes and studies of individual nanoparticles. CNPs were prepared by chemical vapor deposition (CVD) of carbon into the pre-pulled quartz capillaries. By changing pulling parameters and CVD conditions, we fabricated several types …


Lead And Arsenic Contamination In Urban Soils In New York City, Anna Paltseva Sep 2019

Lead And Arsenic Contamination In Urban Soils In New York City, Anna Paltseva

Dissertations, Theses, and Capstone Projects

This dissertation examined total and bioaccessible soil lead (Pb) and arsenic (As) concentrations and their accumulation in commonly grown garden vegetables in New York City (NYC) metropolitan area. Direct oral ingestion of contaminated soil and consumption of plants that have accumulated Pb or As from underlying soil are known human exposure pathways in urban garden soils that often contain elevated levels of contaminants. The research had four components: (1) assessment of the variability of bioaccessible Pb in NYC urban soils; (2) field experiments to evaluate Pb stabilization and As mobilization by phosphate and alternative amendments; (3) development of a new …


Exciton Polaritons In Two-Dimensional Transition Metal Dichalcogenides, Jie Gu Sep 2019

Exciton Polaritons In Two-Dimensional Transition Metal Dichalcogenides, Jie Gu

Dissertations, Theses, and Capstone Projects

Strong interaction between photons and excitons in semiconductors results in the formation of half-light half-matter quasiparticles termed exciton-polaritons. Owing to their hybrid character, they inherit the strong interparticle interaction from their excitonic (matter) component via Coulomb interaction while the photonic component lends the small mass (~105 times lighter than free electrons) and long propagation distances. Additionally, exciton-polaritons also carry properties of the host material excitons such as spin and valley polarization and can be probed via the photons that leak out of the cavities since the photon carries all the information owing to conservation laws. Since the first demonstration …


Semi-Supervised Regression With Generative Adversarial Networks Using Minimal Labeled Data, Greg Olmschenk Sep 2019

Semi-Supervised Regression With Generative Adversarial Networks Using Minimal Labeled Data, Greg Olmschenk

Dissertations, Theses, and Capstone Projects

This work studies the generalization of semi-supervised generative adversarial networks (GANs) to regression tasks. A novel feature layer contrasting optimization function, in conjunction with a feature matching optimization, allows the adversarial network to learn from unannotated data and thereby reduce the number of labels required to train a predictive network. An analysis of simulated training conditions is performed to explore the capabilities and limitations of the method. In concert with the semi-supervised regression GANs, an improved label topology and upsampling technique for multi-target regression tasks are shown to reduce data requirements. Improvements are demonstrated on a wide variety of vision …