Shelby Hatch - Academia.edu (original) (raw)
Papers by Shelby Hatch
Advances in Chemical Physics, Dec 1, 1999
... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Camb... more ... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Cambridge, MA 02139 Peptide, Inc. SHELBY HATCH Departnzent of Chemistry, Princeton University, Princeton, NJ 08544 CONTENTS I. Introduction 11. 111. ...
Protein Science, Apr 1, 1997
All physical and chemical properties are size dependent, and the properties of materials on the n... more All physical and chemical properties are size dependent, and the properties of materials on the nanosize scale have important consequences in wide ranging fields. Exploiting nanoscale behavior will eventually lead scientists to develop devices that can selectively attack diseased cells, increase computer speed or improve chemical and biological sensors. The composition, size, shape and environment of nanosized particles strongly influence their ultimate utility. Chemical dyes were the first use of metal nanoparticles, dating back hundreds of years. Glass blowers used gold and silver colloids as the coloring agents in stained glass windows. Gold nanoparticles (having a size of 10 -15 nm) produce a red or purple hue while silver nanoparticles (with a size of 20 -30 nm) produce a yellow or brown hue. Another very important field leading the development of nanotechnology is catalysis where nanosized materials composed either of transition metals like platinum or metal oxides often facilitate chemical processes by increasing the rate of the reaction. By making catalyst particles very small, large surface areas are achieved with a small volume of material. In the field of medicine, biological and chemical sensors are made of nanoscale particles that are very sensitive to their local environment, making them ideal for detection of trace amounts of many substances, including bacteria, DNA and environmental toxins. The electronics industry is focused on using nanoparticles in data storage devices, which are dependent on the number of memory elements that can be packed into a given area. By making features that are very small, more information can be encoded into a given area increasing computer speed.
PLOS Water
Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase i... more Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase in salinity due to road salt runoff during winter months. Salinization affects soil texture, contaminant transport, microbial activity, and plant growth in wetlands. Therefore, there is a pressing need to understand the dynamics of road salt intrusion in urbanized freshwater ecosystems. We used distributed high-resolution sensors to evaluate the dynamics of road salt intrusion into a wetland complex, Gensburg Markham Prairie (GMP), located in the ex-urban area outside Chicago, Illinois (USA). The in situ sensors measure electrical conductivity (EC), surface and groundwater level, precipitation, water temperature, and air temperature at 30-minute intervals. Water samples were collected monthly from 13 shallow groundwater wells and eight surface water locations and analyzed for Cl-, Mg2+, Na+, Ca2+, and K+. Two-years of continuous data show periodic spikes in EC during winter months, genera...
This dataset includes pH, organic matter content, soil type and total concentrations of Pb, Cu, Z... more This dataset includes pH, organic matter content, soil type and total concentrations of Pb, Cu, Zn, P, Ca, Mg, Fe, Na, and K in soil samples collected up to a depth of 120 cm in Gensburg Markham Prairie (GMP). GMP is a high-quality tall-grass prairie wetland nature preserve in Markham, IL. These measurements were obtained to evaluate the soil quality and the potential for habitat degradation in GMP.
All physical and chemical properties are size dependent, and the properties of materials on the n... more All physical and chemical properties are size dependent, and the properties of materials on the nanosize scale have important consequences in wide ranging fields. Exploiting nanoscale behavior will eventually lead scientists to develop devices that can selectively attack diseased cells, increase computer speed or improve chemical and biological sensors. The composition, size, shape and environment of nanosized particles strongly influence their ultimate utility. Chemical dyes were the first use of metal nanoparticles, dating back hundreds of years. Glass blowers used gold and silver colloids as the coloring agents in stained glass windows. Gold nanoparticles (having a size of 10 -15 nm) produce a red or purple hue while silver nanoparticles (with a size of 20 -30 nm) produce a yellow or brown hue. Another very important field leading the development of nanotechnology is catalysis where nanosized materials composed either of transition metals like platinum or metal oxides often facil...
This laboratory is designed to use the program GAMESS (General Atomic Molecular Electronic Struct... more This laboratory is designed to use the program GAMESS (General Atomic Molecular Electronic Structure System, developed in Gordon research group at Iowa State) through a website called nanoHUB (www.nanoHUB.org) to determine the geometric and electronic properties of numerous small molecules. GAMESS uses ab initio and semi-empirical calculations to determine these properties. Ab initio (“from first principles”) calculations solve the Schrödinger equation using the exact computational expression for the energy of the electrons. The particular ab initio method that we will use for this lab is called HartreeFock (HF). HF uses an approximate wavefunction to solve Schrödinger, so the resulting molecular properties are approximate, but for many applications the accuracy is adequate for interpreting experiments. Semi-empirical calculations use an approximate energy expression for the electrons, but solve for the exact wavefunction associated with this expression. Usually the energy expressio...
Journal of Soils and Sediments, 2019
Purpose Gensburg Markham Prairie (GMP), a high-quality tallgrass prairie and wetland in the Chica... more Purpose Gensburg Markham Prairie (GMP), a high-quality tallgrass prairie and wetland in the Chicago area, is surrounded by high-traffic highways and residential communities. Anthropogenic inputs are a concern given observed ecosystem degradation around the periphery of the prairie. To understand soil quality and the potential for habitat degradation in GMP, we evaluated concentrations of metals and phosphorus in soil profiles, identified possible sources of contamination, and assessed the likelihood that contamination would impact the prairie ecosystem. Materials and methods We collected 15 intact soil cores (to a depth of 120 cm) and 22 surface soil samples (0-10-cm depth), determined the soil type, and measured pH, organic matter, and concentrations of Pb, Cu, Zn, Mg, Fe, K, Ca, and P using ICP-OES. To quantify soil pollution, we calculated the element enrichment factor (EF) and single element pollution index (SEPI) for each sample. We also used principal component analysis (PCA) to interpret relationships between site variables, elemental concentrations, and sources of metals. Results and discussion Heavy metals (Pb, Cu, and Zn) and P were found to accumulate in surface samples. The mean EF values for Pb, Cu, Zn, and P revealed significant enrichment of these elements in the soil profiles. However, SEPI analyses indicate that GMP soils have a low level of contamination. PCA revealed that concentrations are highest for samples with high organic matter content near the ground surface and that Pb, Cu, and Zn have common sources of pollution. Conclusions We observed enrichment of Pb, Cu, Zn, and P because of deposition from the urban built environment, but the enrichment levels are low enough that they are not expected to negatively impact the ecosystem of GMP. The detailed soil chemistry data constitute a spatial contamination map that can be used to assess potential long-term impacts on the ecosystem, such as reduction of plant growth and species diversity, and inform site management and biodiversity conservation efforts.
Advances in Chemical Physics
... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Camb... more ... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Cambridge, MA 02139 Peptide, Inc. SHELBY HATCH Departnzent of Chemistry, Princeton University, Princeton, NJ 08544 CONTENTS I. Introduction 11. 111. ...
Journal of the American Chemical Society, 2004
The rotational mobilities of small solute molecules encapsulated in tetramethyl orthosilicate (TM... more The rotational mobilities of small solute molecules encapsulated in tetramethyl orthosilicate (TMOS) sol-gels have been investigated by EPR spectroscopy of encapsulated nitroxide probes and by high-resolution NMR spectroscopic measurements of transferred NOE's (trNOE's), of T1's, and of T1's in the rotating frame (T1F). The two spectroscopic methods are sensitive to motions on different time scales and hence, are nicely complementary. Suites of neutral, positively, and negatively charged nitroxide probes (EPR) and of simple diamagnetic small molecules (NMR) were selected to disclose influences of electrostatic interactions with the sol-gel walls and to probe the presence of multiple populations of molecules in distinct regions of the sol-gel pores. For neutral and negatively charged solute probes, both techniques disclose a single population with a significantly increased average rotational correlation time, which we interpret at least in part as resulting from exchange between free-volume and transiently immobilized surface populations. The electrostatic attraction between cationic probes and the negatively charged sol-gel walls causes the positively charged probes to be more effectively immobilized and/or causes a greater percentage of probes to undergo this transient immobilization. The EPR spectra directly disclose a population of cationic probes which are immobilized on the X-band EPR time scale: τc J 10-7 s. However, NMR measurements of trNOE's and of T1F demonstrate that this population does exchange with the free-volume probes on the slower time scale of NMR. This approach is equally applicable to the study of solutes within other types of confined spaces, as well. Encapsulation of organic dyes, coordination compounds, colloids, and proteins in tetramethyl orthosilicate (TMOS) derived sol-gels (SG) has been widely used for the study of reactions in confined spaces. 1-16 As a consequence, considerable attention has been devoted to understanding the motional dynamics of encapsulated solvent and solute molecules, notably through NMR measurements of solvent mobilities 17-22 and through solute luminescence depolarization studies of encapsulated probe molecules. 1,12,23-25 A picture has emerged in which SG-encapsulated molecules reside in several regions. 26 Those within the interior of a "cell" (free-liquid region) behave much as though they were in bulk solution, while those in an "interface region", at or near the walls, have more restricted motions. An additional "constraining region" is postulated to include crevices,
Advances in Chemical Physics, Dec 1, 1999
... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Camb... more ... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Cambridge, MA 02139 Peptide, Inc. SHELBY HATCH Departnzent of Chemistry, Princeton University, Princeton, NJ 08544 CONTENTS I. Introduction 11. 111. ...
Protein Science, Apr 1, 1997
All physical and chemical properties are size dependent, and the properties of materials on the n... more All physical and chemical properties are size dependent, and the properties of materials on the nanosize scale have important consequences in wide ranging fields. Exploiting nanoscale behavior will eventually lead scientists to develop devices that can selectively attack diseased cells, increase computer speed or improve chemical and biological sensors. The composition, size, shape and environment of nanosized particles strongly influence their ultimate utility. Chemical dyes were the first use of metal nanoparticles, dating back hundreds of years. Glass blowers used gold and silver colloids as the coloring agents in stained glass windows. Gold nanoparticles (having a size of 10 -15 nm) produce a red or purple hue while silver nanoparticles (with a size of 20 -30 nm) produce a yellow or brown hue. Another very important field leading the development of nanotechnology is catalysis where nanosized materials composed either of transition metals like platinum or metal oxides often facilitate chemical processes by increasing the rate of the reaction. By making catalyst particles very small, large surface areas are achieved with a small volume of material. In the field of medicine, biological and chemical sensors are made of nanoscale particles that are very sensitive to their local environment, making them ideal for detection of trace amounts of many substances, including bacteria, DNA and environmental toxins. The electronics industry is focused on using nanoparticles in data storage devices, which are dependent on the number of memory elements that can be packed into a given area. By making features that are very small, more information can be encoded into a given area increasing computer speed.
PLOS Water
Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase i... more Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase in salinity due to road salt runoff during winter months. Salinization affects soil texture, contaminant transport, microbial activity, and plant growth in wetlands. Therefore, there is a pressing need to understand the dynamics of road salt intrusion in urbanized freshwater ecosystems. We used distributed high-resolution sensors to evaluate the dynamics of road salt intrusion into a wetland complex, Gensburg Markham Prairie (GMP), located in the ex-urban area outside Chicago, Illinois (USA). The in situ sensors measure electrical conductivity (EC), surface and groundwater level, precipitation, water temperature, and air temperature at 30-minute intervals. Water samples were collected monthly from 13 shallow groundwater wells and eight surface water locations and analyzed for Cl-, Mg2+, Na+, Ca2+, and K+. Two-years of continuous data show periodic spikes in EC during winter months, genera...
This dataset includes pH, organic matter content, soil type and total concentrations of Pb, Cu, Z... more This dataset includes pH, organic matter content, soil type and total concentrations of Pb, Cu, Zn, P, Ca, Mg, Fe, Na, and K in soil samples collected up to a depth of 120 cm in Gensburg Markham Prairie (GMP). GMP is a high-quality tall-grass prairie wetland nature preserve in Markham, IL. These measurements were obtained to evaluate the soil quality and the potential for habitat degradation in GMP.
All physical and chemical properties are size dependent, and the properties of materials on the n... more All physical and chemical properties are size dependent, and the properties of materials on the nanosize scale have important consequences in wide ranging fields. Exploiting nanoscale behavior will eventually lead scientists to develop devices that can selectively attack diseased cells, increase computer speed or improve chemical and biological sensors. The composition, size, shape and environment of nanosized particles strongly influence their ultimate utility. Chemical dyes were the first use of metal nanoparticles, dating back hundreds of years. Glass blowers used gold and silver colloids as the coloring agents in stained glass windows. Gold nanoparticles (having a size of 10 -15 nm) produce a red or purple hue while silver nanoparticles (with a size of 20 -30 nm) produce a yellow or brown hue. Another very important field leading the development of nanotechnology is catalysis where nanosized materials composed either of transition metals like platinum or metal oxides often facil...
This laboratory is designed to use the program GAMESS (General Atomic Molecular Electronic Struct... more This laboratory is designed to use the program GAMESS (General Atomic Molecular Electronic Structure System, developed in Gordon research group at Iowa State) through a website called nanoHUB (www.nanoHUB.org) to determine the geometric and electronic properties of numerous small molecules. GAMESS uses ab initio and semi-empirical calculations to determine these properties. Ab initio (“from first principles”) calculations solve the Schrödinger equation using the exact computational expression for the energy of the electrons. The particular ab initio method that we will use for this lab is called HartreeFock (HF). HF uses an approximate wavefunction to solve Schrödinger, so the resulting molecular properties are approximate, but for many applications the accuracy is adequate for interpreting experiments. Semi-empirical calculations use an approximate energy expression for the electrons, but solve for the exact wavefunction associated with this expression. Usually the energy expressio...
Journal of Soils and Sediments, 2019
Purpose Gensburg Markham Prairie (GMP), a high-quality tallgrass prairie and wetland in the Chica... more Purpose Gensburg Markham Prairie (GMP), a high-quality tallgrass prairie and wetland in the Chicago area, is surrounded by high-traffic highways and residential communities. Anthropogenic inputs are a concern given observed ecosystem degradation around the periphery of the prairie. To understand soil quality and the potential for habitat degradation in GMP, we evaluated concentrations of metals and phosphorus in soil profiles, identified possible sources of contamination, and assessed the likelihood that contamination would impact the prairie ecosystem. Materials and methods We collected 15 intact soil cores (to a depth of 120 cm) and 22 surface soil samples (0-10-cm depth), determined the soil type, and measured pH, organic matter, and concentrations of Pb, Cu, Zn, Mg, Fe, K, Ca, and P using ICP-OES. To quantify soil pollution, we calculated the element enrichment factor (EF) and single element pollution index (SEPI) for each sample. We also used principal component analysis (PCA) to interpret relationships between site variables, elemental concentrations, and sources of metals. Results and discussion Heavy metals (Pb, Cu, and Zn) and P were found to accumulate in surface samples. The mean EF values for Pb, Cu, Zn, and P revealed significant enrichment of these elements in the soil profiles. However, SEPI analyses indicate that GMP soils have a low level of contamination. PCA revealed that concentrations are highest for samples with high organic matter content near the ground surface and that Pb, Cu, and Zn have common sources of pollution. Conclusions We observed enrichment of Pb, Cu, Zn, and P because of deposition from the urban built environment, but the enrichment levels are low enough that they are not expected to negatively impact the ecosystem of GMP. The detailed soil chemistry data constitute a spatial contamination map that can be used to assess potential long-term impacts on the ecosystem, such as reduction of plant growth and species diversity, and inform site management and biodiversity conservation efforts.
Advances in Chemical Physics
... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Camb... more ... Department of Chemistry, Princeton University, Princeton, NJ 08544 SONJA KOMAR-PANICUCCI Cambridge, MA 02139 Peptide, Inc. SHELBY HATCH Departnzent of Chemistry, Princeton University, Princeton, NJ 08544 CONTENTS I. Introduction 11. 111. ...
Journal of the American Chemical Society, 2004
The rotational mobilities of small solute molecules encapsulated in tetramethyl orthosilicate (TM... more The rotational mobilities of small solute molecules encapsulated in tetramethyl orthosilicate (TMOS) sol-gels have been investigated by EPR spectroscopy of encapsulated nitroxide probes and by high-resolution NMR spectroscopic measurements of transferred NOE's (trNOE's), of T1's, and of T1's in the rotating frame (T1F). The two spectroscopic methods are sensitive to motions on different time scales and hence, are nicely complementary. Suites of neutral, positively, and negatively charged nitroxide probes (EPR) and of simple diamagnetic small molecules (NMR) were selected to disclose influences of electrostatic interactions with the sol-gel walls and to probe the presence of multiple populations of molecules in distinct regions of the sol-gel pores. For neutral and negatively charged solute probes, both techniques disclose a single population with a significantly increased average rotational correlation time, which we interpret at least in part as resulting from exchange between free-volume and transiently immobilized surface populations. The electrostatic attraction between cationic probes and the negatively charged sol-gel walls causes the positively charged probes to be more effectively immobilized and/or causes a greater percentage of probes to undergo this transient immobilization. The EPR spectra directly disclose a population of cationic probes which are immobilized on the X-band EPR time scale: τc J 10-7 s. However, NMR measurements of trNOE's and of T1F demonstrate that this population does exchange with the free-volume probes on the slower time scale of NMR. This approach is equally applicable to the study of solutes within other types of confined spaces, as well. Encapsulation of organic dyes, coordination compounds, colloids, and proteins in tetramethyl orthosilicate (TMOS) derived sol-gels (SG) has been widely used for the study of reactions in confined spaces. 1-16 As a consequence, considerable attention has been devoted to understanding the motional dynamics of encapsulated solvent and solute molecules, notably through NMR measurements of solvent mobilities 17-22 and through solute luminescence depolarization studies of encapsulated probe molecules. 1,12,23-25 A picture has emerged in which SG-encapsulated molecules reside in several regions. 26 Those within the interior of a "cell" (free-liquid region) behave much as though they were in bulk solution, while those in an "interface region", at or near the walls, have more restricted motions. An additional "constraining region" is postulated to include crevices,