Tectonic and Metamorphic Evolution of the Bernardston Nappe and the Brennan Hill Thrust in the Benardston-Chesterfield Region of the Bronson Hill Anticlinorium

Guidebook for field trips in southwestern New Hampshire, southeastern Vermont, and north-central Massachusetts: New England Intercollegiate Geological Conference, 80th annual meeting, October 14, 15 and 16, 1988, Keene, New Hampshire: Trip A-

CC23 Revised 1979 Emergency Flood Information...Improvement of Flood Damaged Cropland

Campaign Circular 23 This circular is about emergency flood information and how to improve flood damaged cropland

Approximation properties of the qq-sine bases

For $q>12/11$ the eigenfunctions of the non-linear eigenvalue problem associated to the one-dimensional $q$-Laplacian are known to form a Riesz basis of $L^2(0,1)$. We examine in this paper the approximation properties of this family of functions and its dual, in order to establish non-orthogonal spectral methods for the $p$-Poisson boundary value problem and its corresponding parabolic time evolution initial value problem. The principal objective of our analysis is the determination of optimal values of $q$ for which the best approximation is achieved for a given $p$ problem.Comment: 20 pages, 11 figures and 2 tables. We have fixed a number of typos and added references. Changed the title to better reflect the conten

Pond Water Quality in a Claypan Soil

In many areas of the Midwestern United States, a safe and plentiful supply of groundwater is a primary concern. Groundwater is sporadic, unreliable, shallow, and often polluted, even though these same areas often have an annual rainfall in excess of 1 m. The pollution problems associated with these groundwater supplies are both chemical and bacterial. Older wells are often the most dangerous. Linings made of open brick near the surface, cracked casings and covers, and nearby privy, septic tank, and barnyard sites accentuate the problems in shallow groundwater aquifers. High levels of nitrates frequently present in the shallow domestic well water of Illinois were recognized as a health problem by Weart (1948). A preliminary study by Smith et al. (1970) in Washington County, Illinois, of 213 dug wells (2.1-9.2 m deep), 31 drilled wells, and 72 farm ponds showed that water from 73.4 percent of the dug wells exceeded the U.S. Public Health Standard of 10 mg/1 nitrate nitrogen. Only 19.3 percent of the drilled wells exceeded the standard for safe drinking water. All the ponds sampled were found to be well below the U.S. Public Health Standard for nitrate content. Pryor (1956) has reported that because of the geology of the area groundwater supplies in most of Washington County, Illinois, are inadequate. The geologic situation makes successful drilled wells almost nonexistent. Existing low-quality and low-yielding wells are being supplemented by cisterns, transported water, and some ponds. An economic analysis of farm water supplies in Washington County by Moore (1972) revealed that present well water systems are the least costly available, but the quality and quantity make most of these sources unreliable. Alternatives considered by Moore included farm ponds, municipal water supplies, transported water, and various combinations of these potential sources. Moore concluded that farm ponds with a treatment system could be one of the more satisfactory sources of water provided storage is available to meet demands during a prolonged drought. The data reported by Smith et al. ( 19 7 0) concerning nitrate levels in Washington County ponds were from samples collected during late spring. Hill et al. (1962) reported an average maximum level of 3.1 mg/1 of nitrate nitrogen occurred in 14 Ohio ponds with a mean value of 0.17 mg/1. Hill also reported that maximum values for some chemical parameters occurred during early spring months. The authors felt that ponds in Washington County could potentially exceed the public health limit for nitrate because contamination could occur from the same sources causing widespread groundwater contamination. Also, it was felt that differences in watershed types could influence the quality of pond water. Pryor (1956), Smith (1970), and Moore (1972) have shown that Washington County needs an alternate water supply to existing low-quality wells. A project was initiated in December 1970 to determine seasonal and monthly fluctuations of several water quality parameters in farm ponds having different watershed types. Additionally, the premise that Washington County farm ponds could provide water of acceptable quality to repace existing low-quality wells was considered

Induced Ferromagnetism at BiFeO3/YBa2Cu3O7 Interfaces

Transition metal oxides (TMOs) exhibit many emergent phenomena ranging from high-temperature superconductivity and giant magnetoresistance to magnetism and ferroelectricity. In addition, when TMOs are interfaced with each other, new functionalities can arise, which are absent in individual components. Here, we report results from first-principles calculations on the magnetism at the BiFeO3/YBa2Cu3O7 interfaces. By comparing the total energy for various magnetic spin configurations inside BiFeO3, we are able to show that a metallic ferromagnetism is induced near the interface. We further develop an interface exchange-coupling model and place the extracted exchange coupling interaction strengths, from the first-principles calculations, into a resultant generic phase diagram. Our conclusion of interfacial ferromagnetism is confirmed by the presence of a hysteresis loop in field-dependent magnetization data. The emergence of interfacial ferromagnetism should have implications to electronic and transport properties.Comment: 13 pages, 4 figure

Optical Properties of Organometallic Perovskite: An ab initio Study using Relativistic GW Correction and Bethe-Salpeter Equation

In the development of highly efficient photovoltaic cells, solid perovskite systems have demonstrated unprecedented promise, with the figure of merit exceeding nineteen percent of efficiency. In this paper, we investigate the optical and vibrational properties of organometallic cubic perovskite CH3NH3PbI3 using first-principles calculations. For accurate theoretical description, we go beyond conventional density functional theory (DFT), and calculated optical conductivity using relativist quasi-particle (GW) correction. Incorporating these many-body effects, we further solve Bethe-Salpeter equations (BSE) for excitons, and found enhanced optical conductivity near the gap edge. Due to the presence of organic methylammonium cations near the center of the perovskite cell, the system is sensitive to low energy vibrational modes. We estimate the phonon modes of CH3NH3PbI3 using small displacement approach, and further calculate the infrared absorption (IR) spectra. Qualitatively, our calculations of low-energy phonon frequencies are in good agreement with our terahertz measurements. Therefore, for both energy scales (around 2 eV and 0-20 meV), our calculations reveal the importance of many-body effects and their contributions to the desirable optical properties in the cubic organometallic perovskites system.Comment: 5 pages, 4 figure

Definitions of Tillage Systems for Corn

If tillage is defined as the mechanical manipulation of soil, it follows, then, that a tillage system would be the sequence of soil-manipulation operations performed in producing a crop. Today, however, such a definition is recognized as inadequate. We know, for instance, that the management of non-harvested plant tissue (i.e., residue) affects both crop production and soil erosion, and that field operations in which the soil is not tilled have a marked influence on soil condition. Therefore, in this publication, a tillage system is the sequence of all operations involved in producing the crop, including soil manipulation, harvesting, chopping or shredding of residue, application of pesticides and fertilizers, etc. But before describing and comparing the various tillage systems for corn, some terminologies and possible points of confusion need to be addressed. These have to do with primary vs. secondary tillage and the different ways in which similar tillage systems could be defined. PRIMARY AND SECONDARY TILLAGE For many tillage systems, the specific operations can be separated into primary and secondary. Primary tillage loosens and fractures the soil to reduce soil strength and to bring or mix residues and fertilizers into the tilled layer. The implements ( tools ) used for primary tillage include moldboard, chisel and disk plows; heavy tandem, offset and one -way disks; subsoilers; and heavy -duty, powered rotary tillers. These tools usually operate deeper and produce a rougher soil surface than do secondary tillage tools; however, they differ from each other as to amount of soil manipulation and amount of residue left on or near the surface. Secondary tillage is used to kill weeds, cut and cover crop residue, incorporate herbicides and prepare a seedbed. The tools include light- and medium -weight disks, field cultivators, rotary hoes, drags, powered and unpowered harrows and rotary tillers, rollers, ridge- or bed -forming implements, and numerous variations or combinations of these. They operate at a shallower depth than primary tillage tools and provide additional soil pulverization. Equipment that permits primary and/or secondary tillage plus planting in a single operation is also available