Latin American Indigenous Language Research

Latin American Studie

Coal extrusion in the plastic state

Continuous feeding of coal in a compressing screw extruder is described as a method of introducing coal into pressurized systems. The method utilizes the property of many bituminous coals of softening at temperatures from 350 to 425 C. Coal is then fed, much in the manner of common thermoplastics, using screw extruders. Data on the viscosity and extruder parameters for extrusion of Illinois No. 6 coal are presented

Truth Table Invariant Cylindrical Algebraic Decomposition by Regular Chains

A new algorithm to compute cylindrical algebraic decompositions (CADs) is presented, building on two recent advances. Firstly, the output is truth table invariant (a TTICAD) meaning given formulae have constant truth value on each cell of the decomposition. Secondly, the computation uses regular chains theory to first build a cylindrical decomposition of complex space (CCD) incrementally by polynomial. Significant modification of the regular chains technology was used to achieve the more sophisticated invariance criteria. Experimental results on an implementation in the RegularChains Library for Maple verify that combining these advances gives an algorithm superior to its individual components and competitive with the state of the art

Generalised Elliptic Functions

We consider multiply periodic functions, sometimes called Abelian functions, defined with respect to the period matrices associated with classes of algebraic curves. We realise them as generalisations of the Weierstras P-function using two different approaches. These functions arise naturally as solutions to some of the important equations of mathematical physics and their differential equations, addition formulae, and applications have all been recent topics of study. The first approach discussed sees the functions defined as logarithmic derivatives of the sigma-function, a modified Riemann theta-function. We can make use of known properties of the sigma function to derive power series expansions and in turn the properties mentioned above. This approach has been extended to a wide range of non hyperelliptic and higher genus curves and an overview of recent results is given. The second approach defines the functions algebraically, after first modifying the curve into its equivariant form. This approach allows the use of representation theory to derive a range of results at lower computational cost. We discuss the development of this theory for hyperelliptic curves and how it may be extended in the future.Comment: 16 page

Safety of improved Milbond-TX mycotoxin binder when fed to broiler breeders above recommended levels

An increasing concern in poultry nutrition is the effects of mycotoxins in contaminated grain. Several new products have come onto the market that chemically bind these toxins preventing mycotoxicosis. However, many of these products have not been tested for safety if accidently overfed to broiler breeders. In order to simulate a feed mixing error at a feed mill, Improved Milbond-TX® was overfed to broiler breeders to see if this would cause any negative effects on bird performance. A typical corn-soybean based diet supplemented with Milbond-TX mycotoxin binder at three different levels of inclusion (0%, 0.5%, and 1%) was fed to 300 broiler breeder hens. Data were collected on egg production, egg weights, hatchability, fertility, and chick weights from 24 to 35 weeks of age. Eggs per hen housed were not significantly different between the three treatments. The differences in egg weights, hatchability, fertility, and chick weights were also insignificant among the three treatments. We were able to conclude that overfeeding Improved Milbond-TX had no negative effect on bird performance and is safe to feed at a level of up to 1%

Statistical Physics of Self-Replication

Self-replication is a capacity common to every species of living thing, and simple physical intuition dictates that such a process must invariably be fueled by the production of entropy. Here, we undertake to make this intuition rigorous and quantitative by deriving a lower bound for the amount of heat that is produced during a process of self-replication in a system coupled to a thermal bath. We find that the minimum value for the physically allowed rate of heat production is determined by the growth rate, internal entropy, and durability of the replicator, and we discuss the implications of this finding for bacterial cell division, as well as for the pre-biotic emergence of self-replicating nucleic acids.Comment: 4+ pages, 1 figur