Acta Universitaria

3-7

Authors: Matthew Olaniyi Adewumi, Ayodele Jimoh, Olubunmi Abayomi Omotesho

Many observers believe that the on-going liberalization of the world will have dramatic negative effects on small farmers in both developed and developing countries. This study aims to capture the effects of the presence of foreign migrant farmers on small scale farm­ing systems, which are prevalent in Nigeria. The Agricultural Development Project Zone D in which the white farmers settled in the state of Kwara, was used as a case study. Primary data were collected from white farmers as well as from local farmers regarding their situ­ation before and after the arrival of white farmers. Descriptive statistics and analysis of the farm budget were used in evaluating the data. The majority of local farmers (98.63%) transitioned towards sole cropping since the arrival of white farmers in the area. There were significant increases in seed rate, fertilizer and other chemicals, as well as labor inputs per farmer in the area when compared to the situation that was prevalent before the white farmers settled there. Their average farm size, distances between their houses and farms and tractor use reduced significantly, while output per farm size increased considerably since the arrival of white farmers in the area. In order to provide sustainability of the posi­tive development, there is the need to seek a policy option that will calm local farmers who once in a while exhibit signs of dissatisfaction for the way in which white farmers came to settle on their land. These could be achieved through the use of the participatory approach to agricultural development in the area. This approach could also be relevant in other re­gions of the world with similar situations.

19-26

Authors: Juan Manuel Belman Flores, V. Pérez-García

In recent years, and due to problems resulting from global warming, interest has grown in the fields of refrigeration and air conditioning, specifically regarding the use of natural refrigerants and hydrocarbons with low potential for global warming. Such is the case of the use of CO2 as a cold fluid, which has been considered in the scientific community as an adequate alternative to common refrigerants. Nowadays, the use of CO2 in the areas of refrigeration and air conditioning has been recognized at international levels. Therefore, this work aims to show its potential as a natural refrigerant, the causes why this fluid was temporarily replaced by chlorofluorocarbon refrigerants, and its reappearance in the XXI century. It also proposes the use of CO2 in air conditioning in our country by using vapor compression technology, based on the transcritical cycle.

32-35

Authors: Alfredo Campos Mejía, Alexander Pisarchik

Intermittent switches between chaotic and steady-state regimes are observed in experiments with two mutually-coupled diode lasers subject to common white gaussian noise. Both time series and power spectrum analyses yield typical scaling laws for on-off intermittency.

38-44

Authors: Gerardo Ribeiro

Article 5th of the Federal Tax Code of the United States of Mexico establishes that “Tax provisions which institute obligations or tax exceptions to individuals (tax payers) as well as those which establish penalties and sanctions are to be strictly applied.” The purpose of this article is to discuss the concept of “strict application” of tax provisions showing that such concept cannot be sustained based on linguistics nor reason. Therefore a new con­cept is proposed to the tax argument called “making sense” or “constructing sense”.