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Search Results: 1 - 10 of 531745 matches for " H.J.G. Herrera "
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Apparent Digestibility and Growth in Two Swine Genotypes Kept under Pasturing and Confinement Conditions
M. Becerril-Herrera,C. Lemus-Flores,H.J.G. Herrera,M.Alonso-Spilsbury
Pakistan Journal of Biological Sciences , 2006,
Abstract: The study was carried out with 13 Mexican Hairless (MHP) and 21 York-Landrace (Y-L) fattened pigs, randomly distributed in 4 treatments: 1) MHP under total confinement, 2) MHP in pasturing conditions, 3) Y-L in total confinement and 4) Y-L in pasturing conditions, all four groups were fed ad libitum. Morph metric growth in 63 days old pigs showed significant differences (p<0.0001) between breeds; however, at the end of the study (175 days old) significant differences were observed (p<0.05), both between breeds and between productive systems for the following variables: height at withers, hind- and fore- cane perimeters and snout length; indicating that the feeding system caused some hypertrophies in the organs mostly exercised. Results on the percentage of ileal apparent digestibility showed significant differences (p<0.001) between breeds and between productive systems too, whereas in the total apparent digestibility, differences between feeding-productive systems were only significant in the MHP. Results indicate that the MHP is a small size animal with thin limbs, these pigs show a great instinct for forage consumption but are unable to take advantage of this since they can not digest fiber, which ends with the myth that swine autochthonous breeds are able to digest fiber.
Chimeras: an ethical consideration
H.J.G. Zandman
In die Skriflig , 2011, DOI: 10.4102/ids.v45i4.207
Abstract: Scientists have started with experimentation that raises difficult ethical questions. It comprises taking material from the human blueprint (DNA) and inserting this in various test animals. The purpose of such research is noble, namely the alleviation of hu- man suffering. Yet the ethical ramifications of blending the hu- man and animal genome are significant, especially for Chris- tians. The creation of all living entities after their kind and the image-bearing dignity attributed to man both come under se- vere ethical stress for those who presuppose divine order in God’s ecology. For non-Christians the philosophical dilemma ought not to exist in the ethical sense if applied at the purest level. If the human is merely a kind of animal, along with and ontologically not diffe- rent from other animals, there is little logical reason to object to chimeric research apart from a concern about what such re- search and application might do to the order of life pragmati- cally. However, many non-Christian do object. Man is made in God’s image and the concept of human dignity and a universal sense of right and wrong still binds Christians and non-Chris- tians when considering ethics in the field of chimeric research. As the mixing of human stem cells with embryonic animals takes place, certain non-Christian authors protest that human dignity is being diminished and the animal essence is being vio- lated.
Die Staatkundig-administratiewe ontwikkeling van die Sentraal-Afrikaanse Federasie
G. H.J. Snyman
Koers : Bulletin for Christian Scholarship , 1960, DOI: 10.4102/koers.v28i1.1529
Abstract: Daar hoef skynbaar geen twyfel daaroor te wees dat die Britse beleid beweeg in die rigting van die skepping van selfregerende Afrikastate, met lidmaatskap binne die Gemenebes, waar moontlik. In bre trekke het hierdie ontwikkelingsmoontlikheid, waarvan Ghana reeds die toppunt bereik het, dusver ’n neiging getoon om deur sekere fases te gaan.
Kadiri en het geslacht Katawengan van ± 1500 tot ± 1700
H.J. de Graaf,Th. G. Th. Pigeaud
Bijdragen tot de Taal-, Land- en Volkenkunde , 1977,
Electronic band structure of platinum low-index surfaces: an ab initio and tight-binding study. II
H.J. Herrera-Suárez,A. Rubio-Ponce,D. Olguín
Revista mexicana de física , 2012,
Abstract: Presentamos el cálculo de la estructura electrónica de bandas de la superficie ideal del Pt(100) y Pt(110). El cálculo se realizó utilizando la teoría del funcional de la densidad y el método de enlace fuerte. Como resultado de nuestro cálculo presentamos una discusión detallada de los estados resonantes y los estados de superficie. Para la superficie ideal del Pt(100) mostramos que tanto los estados de superficie como los estados resonantes concuerdan aceptablemente con datos experimentales. Para el caso de Pt(110) hallamos que los estados resonantes y de superficie característicos de la dimensionalidad de la superficie, son independientes de la reconstrucción y se reproducen aceptablemente en nuestro cálculo. Al igual que en el trabajo anterior, utilizamos la teoría del funcional de la densidad con el método de ondas planas aumentadas, mientras que los cálculos emp iricos se han hecho utilizando el método de enlace fuerte junto con el método de empalme de las funciones de Green.
Spin axioms in relativistic continuum physics
Herrmann H.J.,Ruckner G.,Muschik W.,Borzeszkowski H.H.v.
Theoretical and Applied Mechanics , 2002, DOI: 10.2298/tam0229169h
Abstract: The 24 components of the relativistic spin tensor consist of 3 + 3 basic spin fields and 9 + 9 constitutive fields. Empirically only 3 basic spin fields and 9 constitutive fields are known. This empirem can be expressed by two spin axioms, one of them identifying 3 spin fields, and the other one 9 constitutive fields to each other. This identification by the spin axioms is materialindependent and does not mix basic spin fields with constitutive properties. The approaches to the Weyssenhoff fluid and the Dirac-electron fluid found in literature are discussed with regard to these spin axioms. The conjecture is formulated, that another reduction from 6 to 3 basic spin fields which does not obey the spin axioms introduces special material properties by not allowed mixing of constitutive and basic fields. .
N.F. Treurnicht,H.J. Joubert,G. Akdogan,G.A. Oosthuizen
South African Journal of Industrial Engineering , 2012,
Abstract: ENGLISH ABSTRACT: Energy use will be one of the main drivers for the achievement of more eco-efficient drilling processes in the automotive industry. Industry awareness of the environmental impact of used cutting emulsions, and the negative effect on worker health, has increased sharply. This has led to innovative lubrication methods such as through-spindle minimal quantity lubrication (MQL) for drilling aluminium-silicon alloys. In this work the performance of MQL at different cutting speeds and feed rates has been investigated using infrared temperature measurements. The results indicate that MQL is a feasible eco-efficient alternative to conventional flood cooling when drilling aluminium-silicon alloys. AFRIKAANSE OPSOMMING: Energiebenutting maak een van die hoofdryfvere uit om eko-doeltreffendheid te behaal in boorprosesse in die motornywerheid. Nywerheidsbewustheid van die omgewingsimpak van gebruikte sny-vloeistowwe, en die negatiewe effek daarvan op werkergesondheid, het skerp toegeneem. Hierdie bewustheid het aanleiding gegee tot die ontwikkeling van smeringsmetodes soos deur-spil minimale hoeveelheid smering (Engels: Minimal Quantity Lubrication, MQL) vir die boor van aluminium-silikon legerings. In hierdie werk word die prestasie van MQL ondersoek teen verskillende snyspoed- en voertempo-kondisies deur middel van infra-rooi temperatuurmeting. Die resultate dui daarop dat MQL ’n lewensvatbare eko-vriendelike alternatief tot konvensionele vloedverkoeling is, wanneer aluminium-silikon legerings geboor word.
A model for assessing Medicago Sativa L. hay quality
G.D.J Scholtz, H.J van der Merwe, T.P Tylutki
South African Journal of Animal Science , 2009,
Abstract: A study was conducted to identify chemical parameters and/or models for assessing Medicago sativa L. (L) hay quality, using near infrared reflectance spectroscopy (NIRS) analysis and Cornell Net Carbohydrate and Protein System (CNCPS) milk prediction as a criterion of accuracy. Milk yield (MY) derived from the CNCPS model, by replacing the average L hay in a complete diet with 168 representative South African L hay samples, was used as a criterion to evaluate and/or develop models for L hay quality grading. The best single predictor of MY was the acid detergent fibre (ADF) content of L hay, which explained 67% of the measured variation. A multiple linear equation (Y = 64.18 – b1ADF – b2ash – b3lignin) explains 96% of the measured variation in MY. The relatively poor performance of crude protein (CP) (r2 = 0.04) and other protein related parameters (r2< 0.25; adjusted-crude protein, ADF-CP, neutral detergent fibre-CP and soluble protein) in predicting MY suggests that protein content of L hay is an unreliable indicator of L hay quality. It is clear that MY derived from the CNCPS model by replacing L hay in a basal diet with others in the South African L hay population can be significantly predicted with high accuracy by the developed empirical model named lucerne milk value (LMV) consisting of only ADF, ash and lignin.
Evaluation of models for assessing Medicago sativa L. hay quality
G.D.J Scholtz, H.J van der Merwe, T.P Tylutki
South African Journal of Animal Science , 2009,
Abstract: A study was conducted to evaluate current proposed models for assessing Medicago sativa L. hay quality, using near infrared reflectance spectroscopy (NIRS) analyses and Cornell Nett Carbohydrate and Protein System (CNCPS) milk production prediction as a criterion of accuracy. Application of the theoretically-based summative total digestible nutrients (TDNlig) model of Weiss et al. (1992), using lignin to determine truly digestible NDF, explained almost all of the variation in milk yield (MY) (r2 = 0.98). However, this model involves high analysis costs to develop and maintain NIRS calibrations and several of its components were poorly predicted by NIRS and therefore, not suited for quality assessment in practice. Current available models (forage quality index (FQI), relative forage quality (RFQ); relative feed value (RFV)) for assessing Medicago sativa L. hay quality revealed lower accuracies (r2 = 0.83, r2 = 0.76, r2 = 0.61, respectively), especially when protein was included in the model (total forage quality index (TFI); r2 < 0.49). The developed empirical equation named lucerne milk value (LMV), including ADF, ash and lignin (Y = b0 – b1ADF – b2ash – b3lignin) (r2 = 0.96), proved to be the most practical, simplistic, economical and accurate quality evaluation model for commercial application.
Prediction of chemical composition of South African Medicago sativa L. hay from a near infrared reflectance spectroscopy spectrally structured sample population
G.D.J Scholtz, H.J van der Merwe, T.P Tylutki
South African Journal of Animal Science , 2009,
Abstract: The near infrared reflectance spectroscopy (NIRS) to predict chemical and digestibility parameters was investigated. Samples (n = 168) representing the spectral characteristics of the South African Medicago sativa L. hay population were chemically analysed for the development of calibration equations. Values for r2 and ratio of prediction to deviation (RPD) used as estimates of calibration accuracy for these parameters were classified as follows: good for dry matter (DM) (r2 = 0.97; RPD = 4.84), crude protein (CP) (r2 = 0.97; RPD = 4.57), acid detergent fibre (ADF) (r2 = 0.95; RPD = 3.97), neutral detergent fibre (NDF) (r2 = 0.95; RPD = 3.99), lignin (r2 = 0.94; RPD = 3.61), ash (r2 = 0.93; RPD = 3.12) and chloride (Cl) (r2 = 0.95; RPD = 3.74); intermediate for NDF-crude protein (NDF-CP) (r2 = 0.91; RPD = 2.96), sugar (r2 = 0.91; RPD = 2.82), in vitro organic matter digestibility at 24 hr (IVOMD24) (r2 = 0.90; RPD = 2.84) and 48 hr (IVOMD48) (r2 = 0.89; RPD = 2.70); and low (RPD <2.31) for soluble protein (SP), ADF-crude protein (ADF-CP), fat, starch, NDF digestibility (NDFD) and the macro minerals (Ca, P, Mg, P, Na and S). The results recorded in the present study indicated that the NIRS technique is acceptable for DM, CP, ADF, NDF, lignin, ash and Cl analysis and for inclusion in quality models.
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