Exact relativistic models of thin disks around static black holes in a magnetic field

The exact superposition of a central static black hole with surrounding thin disk in presence of a magnetic field is investigated. We consider two models of disk, one of infinite extension based on a Kuzmin-Chazy-Curzon metric and other finite based on the first Morgan-Morgan disk. We also analyze a simple model of active galactic nuclei consisting of black hole, a Kuzmin-Chazy-Curzon disk and two rods representing jets, in presence of magnetic field. To explain the stability of the disks we consider the matter of the disk made of two pressureless streams of counterrotating charged particles (counterrotating model) moving along electrogeodesic. Using the Rayleigh criterion we derivate for circular orbits the stability conditions of the particles of the streams. The influence of the magnetic field on the matter properties of the disk and on its stability are also analyzed.Comment: 17 pages, 14 figures. arXiv admin note: text overlap with arXiv:gr-qc/0409109 by other author

Arrangement of Livestock Potential for Climate Change Adjustment in Jimaguayú, Camaguey, Cuba

The purpose of this paper was to make a contribution to the environmental arrangement of the livestock potential in the municipality of Jimaguayú, Camagüey, Cuba. The indicators restrictions, categories, and conflicts of the livestock potential in the region were identified and located on a map. Additionally, the policies, guidelines, regulations and standards for proper environmental management in each livestock area were determined. The study concluded that the potential of livestock activity consists in environmentally recommended use in the main eight of the seventeen secondary environmental areas that make up the region. One of them was considered for secondary use. In terms of categories, the municipality comprises 126.9 km2 without livestock potential, including several settlements and water reservoirs; 115.7 km2 were identified as having a poor potential; 316.3 km2 had a mid-potential; and 225.4 km2 was high. The previous contributed to the environmental arrangement of the livestock potential in the municipality of Jimaguayú, Camagüey. Accordingly, the restrictions, indicators, categories, and conflicts observed in the sector were determined, and their use was recommended for development in the secondary environmental areas with some potential, as well as to set up policies and general and specific guidelines

Arrangement of Livestock Potential for Climate Change Adjustment in Jimaguayú, Camagüey, Cuba

The purpose of this paper was to contribute to environmental arrangement of livestock potential in the municipality of Jimaguayú, Camagüey, Cuba. The indicators, restrictions, categories, and conflicts of livestock potential in the region were identified and placed on a map. Additionally, the policies, guidelines, regulations, and standards for proper environmental management in each livestock raising area were determined. The study concluded that the potential of livestock activity consists in the environmentally recommended use as principal of eight of the seventeen secondary environmental areas that make up the region. One of them was considered for secondary use. In terms of categories, the municipality comprises 126.9 km2 with no livestock potential. It includes several settlements and water reservoirs; 115.7 km2 were identified as poor potential; 316.3 km2 had a mid-potential; and 225.4 km2 was high. The previous contributed to the environmental arrangement of livestock potential in the municipality of Jimaguayú, Camagüey. Accordingly, restrictions, indicators, categories, and conflicts observed in the sector were determined in order to make recommendations for livestock development in the secondary environmental areas with some potential. It was also useful to set up policies and general and specific guidelines

Contaminación bacteriana de Productos Cárnicos Ovinos Comercializados en la Meseta Central de México

El estudio se realizó para evaluar la contaminación microbiológica de las canales de ovino comercializadas en el Altiplano Central Mexicano, durante el período Primavera - Verano 2012. Se recolectaron muestras en tres expendios mayoristas de las canales de ovino antes de la refrigeración, las manos de los trabajadores, y los cuchillos, utilizando la técnica de hisopo húmedo. Las muestras se analizaron para Cuenta Total de Aerobios Viables (TAVC), Cuenta Coliformes Totales (CCT) y Cuenta Coliformes Fecales (FCC), los conteos se determinaron por el método de recuento estándar en placa. Las medias de TAVC de las canales de ovino, las manos del personal, y los cuchillos fueron de 0,99 ± 0,81, 0,78 ± 0,53y 1,84 ± 0,28 log10UFC / mL, respectivamente; no se encontraron diferencias estadísticamente significativas (P <0,05). La media de TCC para las canales fue de 0,74 ± 0,56 log10 UFC / mL y 0,36 ± 0,48 log10UFC/mL para cuchillos, no se encontraron diferencias estadísticamente significativas (P <0,05). No se detectaron FCC en las canales de ovino, el personal y los cuchillos. Los resultados indicaron buenas condiciones higiénicas y de manipulación durante los canales de comercialización

Finite axisymmetric charged dust disks in conformastatic spacetimes

An infinite family of axisymmetric charged dust disks of finite extension is presented. The disks are obtained by solving the vacuum Einstein-Maxwell equations for conformastatic spacetimes, which are characterized by only one metric function. In order to obtain the solutions, it is assumed that the metric function and the electric potential are functionally related and that the metric function is functionally dependent of another auxiliary function, which is taken as a solution of Laplace equation. The solutions for the auxiliary function are then taken as given by the infinite family of generalized Kalnajs disks recently obtained by Gonz\'alez and Reina (MNRAS 371, 1873, 2006), which is expressed in terms of the oblate spheroidal coordinates and represents a well behaved family of finite axisymmetric flat galaxy models. The so obtained relativistic thin disks have then a charge density that is equal, except maybe by a sign, to their mass density, in such a way that the electric and gravitational forces are in exact balance. The energy density of the disks is everywhere positive and well behaved, vanishing at the edge. Accordingly, as the disks are made of dust, their energy-momentum tensor it agrees with all the energy conditions.Comment: Submitted to PR

Agro-industrial evaluation of new sugarcane (Saccaharum spp.) hybrids in the dry tropic under no watering conditions

Objetive: The objective of this research was to select new sugarcane hybrids with better adaptation and performance in the field and industrial within the supply area of ??the Quesería sugar mill of the Beta San Miguel group (BSM). Design/methodology/approach: A group of 11 new hybrids were established in the agroindustrial phase, in order to compare their adaptation and field and the industrial performance using the commercial hybrid Mex 69-290 as control. Results: The results obtained indicated that during the soca cycle and under local soil conditions, the hybrids ColMex 05-484, ColMex 05-38 (c9) and ColMex 05-627, demonstrated the highest estimated field yields, with values ??of 154, 149 and 143 t / ha-1 respectively. Regarding the highest values ??of percentage of sucrose in cane (Pol), at 12 months of age of the plant, it was obtained by the hybrids ColMex 05-147 (16.8%), ColMex 08-38 (C8) (16.5%) and ColMex 05-897 (16.1%), considered by its intermediate cycle maturation curve. Limitations on study/implications: The limitations that could affect the results of the investigation were; the abundance of stones on the topsoil and the poor distribution of rainfall during the development of the crop (1203 mm). Findings/conclusions: It can be concluded that after analyzing the agricultural and industrial performance that, the best hybrid was: ColMex 05-484, surpassing the commercial control Mex 69-290.Objective: To select new sugarcane (Saccaharum spp.) hybrids with better adaptability and higher field and industrial performance, within the supply area of the Quesería Sugar Mill of the Beta San Miguel group (BSM). Design/methodology/approach: We set up a group of 11 new hybrids in the agro-industrial phase in order to compare their adaptability and their field and industrial performance, using the Mex 69-290 commercial hybrid as control. Results: The obtained results indicated that during the soca cycle and under local soil conditions, the ColMex 05-484, ColMex 05-38 (C9), and ColMex 05-627 hybrids produced the highest estimated field yields, with values of 154, 149, and 143 t/ha-1, respectively. The highest percentages of sucrose in cane (Pol) in 12-month-old plants were observed in the ColMex 05-147 (16.8%), ColMex 08-38 (C8) (16.5%), and ColMex 05-897 (16.1%) hybrids, according to their intermediate stage maturity curve. Study limitations/implications: The limitations that could affect the results of the research were the abundance of stones on the topsoil and the poor distribution of rainfall during crop development (1,203 mm). Findings/conclusions: After analyzing the agricultural and industrial performance of several hybrids, we can conclude that ColMex 05-484 was the best, surpassing the Mex 69-290 commercial control