High performance self-compacting concrete with electric arc furnace slag aggregate and cupola slag powder

The development of self-compacting concretes with electric arc furnace slags is a novelty in the field of materials and the production of high-performance concretes with these characteristics is a further achievement. To obtain these high-strength, low-permeability concretes, steel slag aggregates and cupola slag powder are used. To prove the effectiveness of these concretes, they are compared with control concretes that use diabase aggregates, fly ash, and limestone supplementary cementitious materials (SCMs, also called fillers) and intermediate mix proportions. The high density SCMs give the fresh concrete self-compacting thixotropy using high-density aggregates with no segregation. Moreover, the temporal evolution of the mechanical properties of mortars and concretes shows pozzolanic reactions for the cupola slag. The fulfillment of the demands in terms of stability, flowability, and mechanical properties required for this type of concrete, and the savings of natural resources derived from the valorization of waste, make these sustainable concretes a viable option for countless applications in civil engineerin

Durability of high-performance self-compacted concrete using electric arc furnace slag aggregate and cupola slag powder

The current trend in the development of self-compacting concrete with sustainable construction materials has served as a guide to design a novel self-compacting concrete, with siderurgical by-products (steel slag aggregates and cupola slag powder as supplementary cementing material) that also meets the demands of high-performance concrete. This research sets out to clarify the unknown behavior of slag concrete, its durability, which is the ability to withstand any process that tends to deteriorate it. In order to assess the durability of this eco-friendly concrete, three control mixes were manufactured with the same high-quality coarse aggregate (diabase) and three different fines, limestone filler, fly ash and cupola slag powder. All the mixtures were subjected to the same tests, the results demonstrate that steel slag concrete shows an excellent response against carbonation, a slightly lower response against thermal shock cycles, similar drying shrinkage and a superior response against the action of freezing-thawing cycles and abrasion wear in comparison to the control mixes

Perspectiva espiritual y afrontamiento ante la muerte en adultos mayores del centro de México

Objective: To analyze the relationship between spiritual perspective and coping with death in elderly people in the center of Guanajuato, Mexico. Methods: Quantitative, correlational, cross-sectional study, the selection criteria were elderly people aged 60 years and older, attendees of two gerontological centers. Convenience sampling with n=133. The Spiritual Perspective Scale, Bugen's Coping with Death Scale and a sociodemographic data form were used for data collection. Informed consent was signed. The data were analyzed by descriptive statistics, the study variables by Spearman correlation through SPSS version 25. Results: The Spiritual Perspective obtained a mean score of 50.86 and the Bugen scale of 145.65 points. Spearman correlation was performed where r=.375 and p=.000 (p<0.05) were obtained, giving a positive correlation between the study variables. Overall conclusion: A positive and statistically significant correlation was found between spiritual perspective and coping with death. Spirituality has a positive influence on how death is accepted since it is a tool that gives direction to the mourning process, generating feelings of hope, inner renewal and meaning in the elderly; therefore, the greater the spiritual perspective, the better the coping with death.  Objetivo: Analizar la relación entre perspectiva espiritual y afrontamiento ante la muerte en adultos mayores del centro de Guanajuato, México. Método: Estudio cuantitativo, correlacional, de corte transversal, los criterios de selección fueron adultos mayores de 60 años y más, asistentes de dos centros gerontológicos. Muestreo por conveniencia con n=133. Se utilizó la escala de Perspectiva Espiritual, Escala de Bugen de Afrontamiento ante la Muerte y una cédula de datos sociodemográficos para la colecta de datos. Se firmó consentimiento informado. Los datos fueron analizados mediante estadística descriptiva, las variables de estudio mediante correlación de Spearman a través del SPSS versión 25. Resultados principales: La perspectiva espiritual obtuvo una puntuación media de 50.86 y la escala de Bugen de 145.65 puntos. Se realizó correlación de Spearman donde se obtuvo r=.375 y p=.000 (p<0.05), dando una correlación positiva entre las variables de estudio. Conclusión principal: Se encontró una correlación positiva y estadísticamente significativa entre Perspectiva espiritual y Afrontamiento ante la muerte. La espiritualidad influye de forma positiva en cómo se acepta la muerte ya que es una herramienta que da dirección al proceso de duelo generando sentimientos de esperanza, renovación interior y significado en adultos mayores por lo que a mayor perspectiva espiritual se tiene mejor afrontamiento ante la muerte

Viability of Cupola Slag as an Alternative Eco-Binder and Filler in Concrete and Mortars

ABSTRACT: Obtaining new materials capable of meeting society?s demands motivates the search for new solutions that are capable of satisfying twofold requirements: respect for the environment and obtaining more durable and resistant materials. Cupola slag is a by-product generated in the process of obtaining ductile iron. When the slag undergoes rapid cooling, its vitrification is favored, leaving the silica in an amorphous structure and, thus, susceptible to reacting. Through reaction, the slag can develop cementing properties and cement can consequently be partially replaced with residue, providing savings in economic and environmental costs compared to traditional hydraulic binders. In this study, the physical and chemical properties of cupola slag and its recovery process are analyzed. Mortars that incorporate traditional admixtures (fly ash and limestone filler) have been manufactured and consistency and mechanical properties have been compared with mortars that incorporate cupola slag admixture. Mortars have also been manufactured with normalized sand and with Portland cement replacements (0, 10, 20, and 30% by weight) with cupola slag, and both the consistency and the mechanical properties have been compared at 7, 28, 60, and 90 days. The results obtained show the suitability of cupola slag as a binder and as an admixture, with respect to the traditional ones, and how the mechanical properties tend to converge for all of the replacement levels characterized, for ages close to 90 days of age

Perfil fitoquímico, actividad antimicrobiana y antioxidante de extractos de Gnaphalium oxyphyllum y Euphorbia maculata nativas de Sonora, México

The use of synthetic chemical compounds to preserve foods or treat diseases of bacterial origin is limited because they can cause health damage. Therefore, the food and livestock industries seek natural strategies to preserve foods and preserve the health of animals intended for human consumption. In this sense, some extracts of plant from Sonora, Mexico could be an alternative due to the great diversity of plants and the fact that some of them are traditionally used to treat diseases. On the other hand, there are few studies that support the biological activity of ethanolic extracts of Gnaphalium oxyphyllum (E1) and Euphorbia maculata (E2). In this study, phytochemical content was determined by spectrophotometry, antimicrobial activity was determined by agar diffusion and antioxidant activity was evaluated by ABTS, DPPH and FRAP. The results showed that the E1 and E2 extracts had total phenols, total flavonoids, flavones and flavonols, total flavanones and dihydroflavonols, as well as total tannins, total chlorogenic acid and total polysaccharides. In addition, both extracts showed higher antimicrobial activity against Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enterica serovar Typhimurium ATCC 14028 when 1 mg ml-1 was used (P<0.05). In addition, they presented antioxidant activity by the methods of ABTS, DPPH and FRAP. Therefore, the antimicrobial and antioxidant potential of these plants represents a natural alternative to control some Gram-positive and Gram-negative bacteria in the livestock industry, as well as for food preservation.El uso de compuestos químicos sintéticos para conservar alimentos o tratar enfermedades de origen bacteriano está limitado debido a que pueden ocasionar daños en la salud. Por ello, las industrias alimentaria y pecuaria buscan estrategias naturales para conservar alimentos y mantener la salud de los animales destinados a consumo humano. En este sentido, algunos extractos de plantas provenientes de Sonora, México podrían ser una alternativa debido a la gran diversidad de plantas y que algunas de ellas se utilizan tradicionalmente para tratar enfermedades. Por otro lado, son pocos los estudios que sustentan la actividad biológica de los extractos etanólicos de Gnaphalium oxyphyllum (E1) y Euphorbia maculata (E2). En este estudio, el contenido de fitoquímicos se determinó por espectrofotometría, la actividad antimicrobiana se determinó por difusión en agar y la actividad antioxidante se evaluó por ABTS, DPPH y FRAP. Los resultados mostraron que los extractos E1 y E2 presentaron fenoles totales, flavonoides totales, flavonas y flavonoles, flavanonas y dihidroflavonoles totales, así como, taninos totales, ácido clorogénico total y polisacáridos totales. Además, ambos extractos mostraron mayor actividad antimicrobiana contra Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 y Salmonella entérica serovar Typhimurium ATCC 14028 cuando se utilizó 1 mg ml-1 (P<0.05). Además, presentaron actividad antioxidante por los métodos de ABTS, DPPH y FRAP. Por lo anterior, el potencial antimicrobiano y antioxidante de estas plantas representa una alternativa natural para controlar algunas bacterias Gram positivas y Gram negativas en la industria pecuaria, así como para la conservación de alimentos

Lo glocal y el turismo. Nuevos paradigmas de interpretación.

El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global

Seroprevalencia de Mycobacterium avium subespecie paratuberculosis en bovinos sospechosos sacrificados en rastro de Sonora, México

Paratuberculosis is an infectious-contagious disease caused by the bacterium Mycobacterium avium subspecie paratuberculosis (MAP), which affects the digestive tract of ruminants. MAP is distributed worldwide; however, there are no publications on the seroprevalence of this disease in cattle in the state of Sonora. Therefore, the objective of this study was to detect MAP seropositivity in cattle in Sonora, as well as to know its apparent prevalence in a population of adult cattle with emaciation and cachexia. Three hundred and eighty-five serum samples were analyzed from 370 female and 15 male cattle, older than 3 years, born in the state with signs of emaciation and cachexia. Data were collected on age, breed, zootechnical purpose and municipality of origin. The zootechnical purpose of the animals was mostly dual purpose cattle with 84.93% (370/385). The samples were processed using the commercial ELISA test. The results show an apparent seroprevalence of 2.08% (8/385) and the municipalities that presented seropositive animals were Hermosillo with 3 samples, as well as Guaymas, Huachinera, Ures, Villa Pesqueira and Fronteras, with one sample each. The present study demonstrates for the first time seropositivity to Mycobacterium avium subspecies paratuberculosis in cattle in Sonora. In addition to a low apparent seroprevalence in the cattle population sampled. The presence of MAP in Sonora, which could be considered a neglected disease, highlights the need to know its possible role in public health in MexicoLa paratuberculosis en una enfermedad infecto-contagiosa causada por la bacteria Mycobacterium avium subespecie paratuberculosis (MAP), y afecta al aparato digestivo de los rumiantes. MAP es de distribución mundial, sin embargo, no hay publicaciones de la seroprevalencia en bovinos de esta enfermedad en el estado de Sonora. Por lo anterior, el objetivo de este trabajo fue detectar la seropositividad a MAP en ganado bovino de Sonora, así como conocer su prevalencia aparente en una población de bovinos adultos con emaciación y caquexia. Se analizaron 385 muestras de suero de bovinos, 370 de hembras y 15 de machos, mayores de 3 años, nacidos en la entidad con signos de emaciación y caquexia. Se recopilaron datos sobre edad, raza, fin zootécnico y municipio de origen. La finalidad zootécnica de los animales fue en su mayoría bovinos de doble propósito con 84.93% (370/385). Las muestras procesaron mediante la prueba comercial ELISA. Los resultados muestran una seroprevalencia aparente de 2.08% (8/385) y los municipios que presentaron animales seropositivos fueron Hermosillo con 3 muestras, así como, Guaymas, Huachinera, Ures, Villa Pesqueira y Fronteras, con una muestra cada uno. El presente estudio demuestra por primera vez la seropositividad a Mycobacterium avium subespecie paratuberculosis en ganado bovino de Sonora. Además de una baja seroprevalencia aparente en la población de bovinos muestreada. La presencia de MAP en Sonora, la cual podría ser considerada como una enfermedad olvidada, pone en evidencia la necesidad de conocer su posible rol en la salud pública de Méxic

Protección contra herbivoría en reforestación de terreno árido degradado, con palo verde(Parkinsonia microphylla Torr.)

ABSTRACT Rehabilitating degraded arid lands requires overcoming biotic and abiotic limitations. The objective of this study was to determine if low-cost protective shelters improve the survival and growth of palo verde (Parkinsonia microphylla) plants during the first year of reforestation at degraded sites in the Sonoran Desert. Protective shelters were built using pruning waste and plastic containers. For one year, 264 palo verde plants were subjected to differential protection treatments against herbivores: unprotected, and protected by branch shelters, polyethylene terephthalate (PET) shelters or both), and their survival and height were monitored. The survival of plants with the use of protective shelters was greater than that of unprotected plants (34.9-56.7 vs. 1.8%, x2 = 63.5; p < 0.0001); also, the heights of protected plants were greater. The use of shelters is an alternative for reforestation with palo verde in degraded lands in the Sonoran desert.RESUMEN Rehabilitar terrenos degradados áridos, demanda superar limitaciones bióticas y abióticas. El objetivo del estudio fue conocer si refugios protectores de bajo costo, mejoran la supervivencia y el crecimiento de plantas de palo verde (Parkinsonia microphyllá), durante el primer año de reforestación en sitios degradados del Desierto Sonorense. Se construyeron refugios protectores reutilizando desechos de poda y envases plásticos. Durante un año, 264 plantas de palo verde fueron sometidas a tratamientos diferenciales de protección contra herbívoros (sin protección, y con protección por refugios de ramas, PET o ambos), y se monitoreó su supervivencia y altura. La supervivencia de plantas con el uso de refugios protectores fue mayor que la de las plantas sin protección (34.9-56.7 vs. 1.8%, x2 = 63.5; p < 0.0001); también las alturas de las plantas protegidas fueron mayores. El uso de refugios es una alternativa para la reforestación con palo verde en terrenos degradados del desierto Sonorense

Addition of a Mixture of Plant Extracts to Diets for Growing-Finishing Pigs on Growth Performance, Blood Metabolites, Carcass Traits, Organ Weight as a Percentage of Live Weight, Quality and Sensorial Analysis of Meat

The effect of plant extracts (PE; artichoke, celery, beet, onion, garlic, spinach, avocado, oats, and parsley) in the diet of growing pigs under heat stress was investigated. Parameters included growth performance, blood constituents, carcass characteristics, organ percentage, quality and sensory appraisal of the pork. The study was performed during the Mexican summer, using 60 pigs. Treatments included the control, to which 0.1% PE, and 0.15% PE were added. The use of PE (0.1 and 0.15%) generated an increase in the average daily gain (ADG, by 10.0% for both treatments), and final live weight (LW, by 6.3% and 6.8%) (p &lt; 0.05). The level of blood albumin at 95 kg was higher when supplementing with 0.1% PE (p &lt; 0.05). At 120 kg LW, creatine kinase values showed a tendency to be different (p = 0.07). Carcass weight increased (p &lt; 0.05) when adding PE. Supplementation with 0.1% PE decreased (p &lt; 0.05) the red/green (a *) hue of the meat, whereas supplementation with 0.1% and 0.15% PE increased the yellow/blue (b *) hue (p &lt; 0.05). The addition of PE improves pig growth performance, and carcass weight by reducing the negative effects of heat stress, without markedly modifying blood constituents, meat quality, and sensory attributes of the pork