oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 149 )

2019 ( 797 )

2018 ( 890 )

2017 ( 892 )

Custom range...

Search Results: 1 - 10 of 528582 matches for " D. M.;Alem Sobrinho "
All listed articles are free for downloading (OA Articles)
Page 1 /528582
Display every page Item
Biological nitrogen removal over nitritation/denitritation using phenol as carbon source
Queiroz, L. M.;Aun, M. V.;Morita, D. M.;Alem Sobrinho, P.;
Brazilian Journal of Chemical Engineering , 2011, DOI: 10.1590/S0104-66322011000200004
Abstract: a laboratory scale activated sludge sequencing batch reactor was operated in order to obtain total removal of influent ammonia (200; 300 and 500 mg nh3-n.l-1) with sustained nitrite accumulation at the end of the aerobic stages with phenol (1,000 mg c6h5oh.l-1) as the carbon source for denitrifying microorganisms during the anoxic stages. ammonia removal above 95% and ratios of (no2--n / (no2--n + no3--n)) ranging from 89 to 99% were obtained by controlling the dissolved oxygen concentration (1.0 mg o2.l-1) and the ph value of 8.3 during the aerobic stages. phenol proved to be an adequate source of carbon for nitrogen removal via nitrite with continuous feeding throughout part of the anoxic stage. nitrite concentrations greater than 70.0 mg no2--n.l-1 inhibited the biological denitritation process.
EFECTO DE LA TEMPERATURA DEL SEMEN SOBRE LA RESPUESTA REPRODUCTIVA DE CERDAS
Alemán,D; Alfaro,M; Hurtado,E;
Idesia (Arica) , 2006, DOI: 10.4067/S0718-34292006000300005
Abstract: with the purpose of evaluating the effect of semen temperatures on the reproductive answer of nuliparous, primiparous and multiparous sows, there were used 91 yorkshire and landrace half-breed sows, in a commercial farm located in sabaneta, monagas state, venezuela. the treatments were distributed in a factorial arrangement (3x2) on a complete random design. the factors identified were the following: categories of parturition (nuliparous, primiparous and multiparous) and semen temperatures (37 °c and 16-18 °c). the dependent variables were farrowing rate (fr), number of piglets born alive (npba) and number of total born piglets (ntbp). the data were analyzed through variance analysis by the method of the minimum squares, with a lineal model of fixed effects, for an unequal number of observations. it was observed an effect (p<0.05) semen tempera-ture and interaction categories of parturition x semen temperature on the farrowing rate. the average values found were 79.13% for 37 °c and 55.42% for 16-18 °c, while the largest average (85.57%) in interactions occurred in nuliparous sows inseminations with semen at 37 °c. the npba and ntbp did not present difference (p>0.05) in factors of study. in conclusion, interaction categories of parturition x semen temperature affect reproductive answer (farrowing rate).
EFECTO DE LA TEMPERATURA DEL SEMEN SOBRE LA RESPUESTA REPRODUCTIVA DE CERDAS EFFECT OF SEMEN TEMPERATURE ON THE REPRODUCTIVE ANSWER OF SOWS
D Alemán,M Alfaro,E Hurtado
IDESIA , 2006,
Abstract: Con el fin de evaluar el efecto de la temperatura del semen en cerdas nulíparas, primíparas y multíparas, sobre la respuesta reproductiva, se utilizaron 91 cerdas mestizas de las razas Yorkshire y Landrace, en una granja comercial ubicada en Sabaneta, Estado Monagas, Venezuela. Se utilizó un dise o completamente al azar con arreglo factorial de tratamientos 3 x 2. Los factores identificados fueron: categoría de parto (nulíparas, primíparas y multíparas) y temperatura del semen (37 °C y 16-18 °C). Las variables dependientes medidas fueron: Porcentaje de partos (PP), número de lechones nacidos vivos (NLNV) y número de lechones nacidos totales (NLNT). Los datos se estudiaron mediante análisis de la varianza, por el método de los mínimos cuadrados, con un modelo lineal de efectos fijos, para desigual número de observaciones. Se observaron el efecto (P<0,05) de la temperatura del semen y la interacción categoría de parto por temperatura del semen sobre el porcentaje de partos. Los valores promedios encontrados fueron: 79,13% para 37 °C y 55,42% para 16-18 °C; mientras que el mayor promedio (85,57%) en la interacción ocurrió en las cerdas nulíparas inseminadas con semen a 37 °C. El NLNV y NLNT no presentaron diferencias (P>0,05) entre los factores bajo estudio. En conclusión, la interacción categoría de parto por temperatura del semen afecta la respuesta reproductiva (porcentaje de partos). With the purpose of evaluating the effect of semen temperatures on the reproductive answer of nuliparous, primiparous and multiparous sows, there were used 91 Yorkshire and Landrace half-breed sows, in a commercial farm located in Sabaneta, Monagas state, Venezuela. The treatments were distributed in a factorial arrangement (3x2) on a complete random design. The factors identified were the following: categories of parturition (nuliparous, primiparous and multiparous) and semen temperatures (37 °C and 16-18 °C). The dependent variables were farrowing rate (FR), number of piglets born alive (NPBA) and number of total born piglets (NTBP). The data were analyzed through variance analysis by the method of the minimum squares, with a lineal model of fixed effects, for an unequal number of observations. It was observed an effect (P<0.05) semen tempera-ture and interaction categories of parturition x semen temperature on the farrowing rate. The average values found were 79.13% for 37 °C and 55.42% for 16-18 °C, while the largest average (85.57%) in interactions occurred in nuliparous sows inseminations with semen at 37 °C. The NPBA and NTBP did not present difference (P>0.05) in f
Influencia de la composición química, del tratamiento térmico y del acabado superficial en el bioensuciamiento de aceros inoxidables austeníticos
Sarró, M.,Alemán, O.,Moreno, D. A.,Roso, M.
Revista de Metalurgia , 2004,
Abstract: The main objective of this study was to analyse the biofouling processes in three kinds of stainless steels used normally in industry (UNS S30400, UNS S30403 and UNS S31600), with different surface treatments after grinding and polishing. The study was developed using two microscopy techniques. Scanning Electron Microscopy (SEM) was used to evaluate the microorganisms distribution in the materials, and Epifluorescence Microscopy was used to evaluate the viability of cells in the biofilm. The results revealed the influence of the material, heat treatment, surface treatment and roughness in the biofouling processes in the stainless steel assays. El objetivo de este estudio es analizar el comportamiento frente al bioensuciamiento de tres aceros inoxidables austeníticos, utilizados habitualmente en la industria (UNS S30400, UNS S30403, UNS S31600), con diferentes tratamientos térmicos y acabados superficiales de lijado y pulido. Para ello, se utilizaron diferentes técnicas de microscopía. Por microscopía electrónica de barrido se evaluó la distribución de los microorganismos en la superficie del material, y por microscopía de epifluorescencia se analizó la viabilidad de los mismos. Los resultados obtenidos revelan una influencia del material, del tratamiento térmico, del acabado superficial y de la rugosidad en el bioensuciamiento de los aceros inoxidables austeníticos.
Neutrinos and Electromagnetic Gauge Invariance
F. Pisano,J. A. Silva-Sobrinho,M. D. Tonasse
Physics , 1996, DOI: 10.1016/S0370-2693(96)01250-6
Abstract: It is discussed a recently proposed connection among U(1)$_{\rm em}$ electromagnetic gauge invariance and the nature of the neutrino mass terms in the framework of $\mbox {SU(3)}_C\otimes G_W \otimes {\mbox U(1)}_N$, $G_W$ = SU(3)$_L$, extensions of the Standard Model. The impossibility of that connection, also in the extended case $G_W $ = SU(4)$_L$, is demonstrated.
Constraints on free parameters of the simplest bilepton gauge model from the neutral kaon system mass difference
F. Pisano,J. A. Silva-Sobrinho,M. D. Tonasse
Physics , 1998, DOI: 10.1103/PhysRevD.58.057703
Abstract: We consider the contributions of the exotic quarks and gauge bosons to the mass difference between the short- and the long-lived neutral kaon states in $SU(3)_C \times SU(3)_L \times U(1)_N$ model. The lower bound $M_{Z'} \sim$ 14 TeV is obtained for the extra neutral gauge boson ${Z'}^0$. Ranges for values of one of the exotic quark masses and quark mixing parameters are also presented.
Experimentation on Tool Wear and Surface Roughness in AISI D2 Steel Turning with WC Insert  [PDF]
N. López-Luiz, O. Jiménez Alemán, F. Alvarado Hernández, M. Montoya Dávila, V. H. Baltazar-Hernández
Modern Mechanical Engineering (MME) , 2018, DOI: 10.4236/mme.2018.83014
Abstract: The Taguchi method, based on an orthogonal arrangement (L9, 33), the vari-ance analysis, the signal-to-noise ratios and the response surface methodol-ogy have been used to optimize maximum flank wear (VBmax) and surface roughness (Ra) of the cutting tool when turning a hardened steel AISI D2 (65 HRC) with PVD—TiAlN coated WC insert upon dry environment. By em-ploying regression models; cutting speed, cutting depth and feed rate, which optimize maximum flank wear and surface roughness were validated. Results of relation signal-to-noise ratios, showed that with cutting speed of 200 m/min, cutting depth of 0.2 mm and feed rate of 0.20 mm/rev, Ra is opti-mized. With cutting speed of 150 m/min, cutting depth of 0.4 mm and feed rate of 0.3 mm/rev, VBmax is optimized. Through the variance analysis it was concluded that the depth of cut was the main parameter that affected on the surface roughness; whereas, the feed rate was the most influential parameter on the flank wear. Confirmation test results showed that the Taguchi method was very successful in the optimization of machining parameters for mini-mum surface roughness and flank wear in the turning of the D2 steel.
Child labor and childhood behavioral and mental health problems in Ethiopia
AA Alem, A Zergaw, D Kebede, M Araya, M Desta, T Muche, D Chali, G Medhin
Ethiopian Journal of Health Development , 2006,
Abstract: Background: According to ILO estimates, at least 180 million children aged 5 to 14 years are currently engaged in fulltime work in the developing countries. However, very little information exists about childhood behavioral and mental disorders in Ethiopia. Objective: The objectives of this study are to estimate the prevalence and describe the nature of behavioral and mental health problems, as well as child abuse, nutritional problems, gross physical illness and injury among child laborers aged 8 to 15 years in Ethiopia. However, only the behavioral and mental health problems of the study population are examined here. Methods: A cross-sectional survey of children aged 8 to 15 years, and who were engaged in fulltime work in different formal and informal sectors non-laborers, was conducted in four major towns of Ethiopia. The screening instrument known as Reported Questionnaire on Children (RQC) and a diagnostic instrument known as the Diagnostic Interview for Children and Adolescents ( DICA) were used to detect symptoms and signs of behavioral and mental problems in the children. br> Results: A total of 2000 child laborers and 400 non-laborers were interviewed using RQC to screen for probable cases of behavioral and mental problems. Of these, 50% of the laborers and 42% of the non-laborers were males. The mean age of the laborers was 13.8 ±1.8 years while that of the non-laborers was 12.2 ±2.1 years. More females (76.8%) were found to have been engaged in domestic labor than males. The RQC interview screened 9.4% (n=226) of the children as probable cases of mental/ behavioral disorders, (14.0% non-laborers and 8.5% laborers). The second stage DICA interview gave an overall prevalence of 5.5% (4.9% in laborers and 8.8% in non-laborers). Conclusion: The prevalence of childhood behavioral and mental disorders in this study is within the range reported in previews studies conducted on children of the same age group. However, the lower prevalence of childhood disorders in the child laborers compared to that of the non-laborers found in the current study is probably due to selection bias or healthy workers effect. Thus, further study is recommended to explain this unexpected finding. The Ethiopian Journal of Health Development Vol. 20 (2) 2006: 119-126
Solidificación-Estabilización de Cromo, Níquel y Plomo en una Matriz Sólida de Hormigón Fabricada con Cemento Portland
Lara-Díaz,René A; Melgoza-Alemán,Rosa M;
Información tecnológica , 2009, DOI: 10.4067/S0718-07642009000100005
Abstract: the technique of cementation was validated as an alternative method for the solidification-stabilization of heavy metal synthetic wastes, chromium, nickel and lead, using concrete solid cylinders made of portland cement. the cementation process takes place starting with a concrete mixture base with compressive strength of 29.4 n/mm2. metals were incorporated as metallic salts in the mixing water. tests of compressive strength, leaching of metals by pect with atomic absorption were performed and retention efficiencies were calculated. concrete made with portland cement is appropriate for the solidification-stabilization of nickel and lead, with maximum concentrations of 0.43% of nickel and 1.94% of lead in concrete.
Molecular characterization of Lotus corniculatus cultivars using transferable microsatellite markers
Alem,Diego; Narancio,Rafael; Díaz Dellavalle,Paola; Rebuffo,Mónica; Zarza,Rodrigo; Dalla Rizza,Marco;
Ciencia e investigación agraria , 2011, DOI: 10.4067/S0718-16202011000300015
Abstract: lotus corniculatus l. is the most important agricultural species in the genus lotus and is the most widely distributed lotus species worldwide. l. corniculatus genotypes form complex groups that are difficult to recognize both morphologically and biochemically. given the extensive and expensive process of isolating simple sequence repeats (ssr, also called microsatellites), the possibility of using microsatellites already identified in related species is highly attractive. the aim of this work was the identification and validation of transferable microsatellite markers in l. corniculatus, and using those markers to study the genetic variability among four cultivars. each cultivar of l. corniculatus was represented by 15 genotypes. ten microsatellite markers were evaluated, and from those, four were selected based on their discriminative values observed among cultivars. we detected 29 alleles for the four markers, and there was an average of 7.25 alleles per locus. the marker tm0197 had the fewest number of alleles (5) and tm0083 had the highest number of alleles (10). the polymorphic information content (pic) for the selected markers varied from 0.19 to 0.35, and the markers were therefore classified as highly informative. based on the markers, we found high variability between individuals of the same cultivar. the use of transferable microsatellite markers could be useful to differentiate individuals at a relatively low cost, showing a great potential for use in breeding programs.
Page 1 /528582
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.