Interacting Electrons on a Square Fermi Surface

Electronic states near a square Fermi surface are mapped onto quantum chains. Using boson-fermion duality on the chains, the bosonic part of the interaction is isolated and diagonalized. These interactions destroy Fermi liquid behavior. Non-boson interactions are also generated by this mapping, and give rise to a new perturbation theory about the boson problem. A case with strong repulsions between parallel faces is studied and solved. There is spin-charge separation and the square Fermi surface remains square under doping. At half-filling, there is a charge gap and insulating behavior together with gapless spin excitations. This mapping appears to be a general tool for understanding the properties of interacting electrons on a square Fermi surface.Comment: 25 pages, Nordita preprint 94/22

A Third-order and a Fourth-order Iteration Process for Nonlinear Equations

Convergence proof and procedure for third-order and fourth-order iteration process for nonlinear equations - Newton-Raphson second-order iteratio

Matrix methods for calculating zeros, coefficients, Christoffel numbers, and derivatives of some orthogonal polynomials

Jacobi matrix method for calculating zeros, coefficients, Christoffel numbers, and derivatives of orthogonal polynomial

A first order iteration process for simultaneous equations

First order iteration process for solutions of simultaneous equation

Written Thoughts, WAPA 2: The Desires of American Girls

An essay written by Luther H. Gulick circa 1913. Digitized from Box 1, folder 12, Camping in Maine Collection, MS 83

Written Thoughts, WAPA I: Camp Fire Girls and the New Relation of Women to the World

Reprints of an address delivered by Dr. Luther H. Gulick before the National Education Association, July, 1912, and the Connecticut Valley Public Recreation Conference in Springfield, Massachusetts, April, 1912. Digitized from Box 1, folder 12, Camping in Maine Collection, MS 83

Written Thoughts, WAPA 3: Aims and Policy

Essays written by Luther H. Gulick including Camp Fire is an Army, not a Hospital; Patriotism and the Camp Fire Girls; and Team Work in Social Life, an Address to the Girls of America. Digitized from Box 1, folder 12, Camping in Maine Collection, MS 83

Coping and Social Support for Parents of Children with Autism

The increased incidence of autism in children impacts families, educators, and health professionals. A descriptive survey design was used to obtain responses from parents of autistic children in public schools. Data collection instruments included The Social Support Index, SSI (McCubbin, Patterson, and Glynn, 1982), and The Family Crisis Oriented Personal Evaluation Scale, F-COPES (McCubbin, Olson, and Larsen, 1981 ). The majority of parents of autistic children perceived that they had support within their families and communities. One half of the families identified serious stressors in addition to autism. Acquiring social support and reframing were the coping strategies used most frequently. The school nurse is in a position to provide support to parents of children with autism and special needs, and integrate coping and social support assessments into practice

Marketing activities and problems of part-time farmers

This study was designed to explore one aspect of this peculiar set of problems with which part-time farmers are faced-that of marketing surplus agricultural products from their small farms. It must be recognized that the products marketed sad the markets used by part-time farmers are in general the same products and the same markets involved in marketings from full-time commercial farms. However, the thesis of this study was that the nature of part-time farming particularly with respect to (1) small scale marketings, (2) the secondary interest of the part-time farmer in his off-farm relative to his off-farm job, and (3) the labor com-petition between the off-farm job and the farm created many unique market situations not generally experienced by commercial farmers.It was also recognised that the primary interests of most part-time farmers in their farms were to produce food for home consumptions, provide for future security, or the desirableness of rural living rather than to increase cash income for their family. This fact had been fairly well established by ether studies.² Consequently, the interest of part-time farmers in markets is not likely to be very intense. However, the fact that many part-time farmers have surplus production which is or could be marketed. Many part-time farmers produce certain products, such as tobacco, specifically for the market. In addition, the rather limited use of agricultural resources (particularly physical resources) on many parttime farms suggests the possibility of further development of commercial enterprises on these farms. The purpose of this study can be stated as follows: 1. To show what part-time farmers sell, where they sell, and method of marketing. 2. To determine the relationship between certain factors (such as size of farm, family size and composition, and age of operator) and what is produced and sold from part-time farms. 3. To determine and appraise marketing problems and limitations encountered by part-time farmers