13 research outputs found

    The reaction of slag in cement: theory and computer modelling

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    In this study, theoretical models available for the reaction of both pure slag\ud (alkali-activated) and slag-blended cement are reviewed. They were developed by using stoichiometric computations

    Expansive Strontium Aluminate Cements

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    Рівень продуктів пероксидного окиснення ліпідів у крові поросят за дії кормової добавки “Силімевіт”

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    Intensive pig breeding has been reported in the literature to suggest that early weaning of piglets from sows is an extreme stimulus that reduces the protective and adaptive responses of piglets. That is why the aim of the study was to study the effect of the feed additive “Sylimevit” on the level of lipid peroxidation products of piglets after weaning. Two groups of piglets were formed – control and experimental in the amount of 10 individuals in each group, selected on the principle of analogs – age, breed and body weight. During the weaning period, the piglets were kept under the sow in special machines, had constant access to the mother, and from the age of 5 days – free access to concentrated feed. While feeding of animals was carried out in accordance with the norms for a given age of pigs. Prior to the study, a clinical and physiological examination of the piglets was performed. Their general condition and activity when eating food were taken into account. On the 28th day of life, the piglets were weaned from the sow and regrouped from different nests in order to be further maintained during the period of fattening and rearing with a change in the structure of the diet, which served as technological stress for the animals. From the age of 5 days, piglets of all groups were fed pre-starter feed. Piglets of the experimental group, from 21 to 40 days of age, were additionally fed the feed supplement “Sylimevit” at a dose of 100 mg/kg body weight per day. The technological stress of weaning piglets from sows is accompanied by a gradual probable intensification of lipid peroxidation processes. Feeding Sylimevit feed to piglets after weaning helped to reduce the content of intermediate and final products of lipid peroxidation: lipid hydroperoxides – by 52 % (P < 0.001) and TBA-active products – by 22.5 % (P < 0.01). Thus, feeding the piglets of the experimental group of the feed additive “Sylimevit” helped to suppress the processes of lipid peroxidation in animals. Thus, the results of the use of feed additive “Sylimevit” in weaned piglets showed a pronounced antioxidant effect. The components of the feed additive directly interacted with reactive oxygen species and free radicals, preventing the development of oxidative stress.При інтенсивному веденні свинарства з повідомлень в літературі відомо, що раннє відлучення поросят від свиноматок є екстремальним подразником, який спричиняє зниження захисно-пристосувальних реакцій організму поросят. Саме тому метою проведених досліджень було вивчити вплив кормової добавки “Силімевіт” на рівень продуктів пероксидного окиснення ліпідів організму поросят після відлучення. Було сформовано дві групи поросят – контрольну і дослідну в кількості 10 особин у кожній групі, підібраних за принципом аналогів – віком, породою і масою тіла. У підсисний період поросята утримувалися під свиноматкою у спеціальних станках, мали постійний доступ до матері, а з 5-добового віку – вільний доступ до концентрованих кормів. Годівля тварин проводилась відповідно до норм для даного віку свиней. Перед проведенням досліджень здійснювали клінічно-фізіологічне обстеження поголів’я поросят. Враховували їхній загальний стан та активність при поїданні корму. На 28 добу життя поросят відлучали від свиноматки та перегруповували з різних гнізд з метою подальшого утримання у період відгодівлі та дорощування зі зміною структури раціону, що слугувало технологічним стресом для організму тварин. Починаючи з 5-добового віку поросят усіх груп підгодовували престартерним комбікормом. Поросятам дослідної групи, починаючи з 21- до 40-добового віку, додатково згодовували кормову добавку “Силімевіт” у дозі 100 мг/кг маси тіла на добу. Технологічний стрес відлучення поросят від свиноматок супроводжується поетапним вірогідним посиленням процесів пероксидного окиснення ліпідів. Згодовування кормової добавки “Силімевіт” поросятам після відлучення сприяло зниженню вмісту проміжних і кінцевих продуктів пероксидного окиснення ліпідів: гідроперекисів ліпідів – на 52 % (Р < 0,001) і ТБК-активних продуктів – на 22,5 % (Р < 0,01). Отже, згодовування поросятам дослідної групи кормової добавки “Силімевіт” сприяло пригніченню процесів пероксидного окиснення ліпідів в організмі тварин. Таким чином, результати застосування кормової добавки “Силімевіт” поросятам при відлученні показали виражену антиоксидантну дію. Складники кормової добавки безпосередньо взаємодіяли з активними формами кисню та вільними радикалами, запобігаючи розвитку оксидаційного стресу

    The influence of feed additive “Sylimevit” on indicators of the immune system of piglets at weaning

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    In the development of adaptive reactions during weaning, biological mechanisms are involved with the complete mobilization of the functional reserve, an increase in the level of catecholamines, corticosteroids, and mediators, which is accompanied by a violation of the nitrogen balance in the body, enzymopathy, and endotoxemia—the work aimed to investigate humoral and non-specific immunity indicators in piglets after weaning. Experiments were conducted based on the Ltd “KOSHET” of the Mukachiv district of the Zakarpattia region. Two groups of piglets were formed – control and experimental in the number of 10 individuals in each group, selected according to the principle of analogs – age, breed, and body weight. Weaning piglets from sows at 28 days suppress the humoral link of natural resistance. A decrease in lysocin and bactericidal activity of blood serum was established at 40.56 ± 1.75 and 21.22 ± 1.05 %. The content of circulating immune complexes in the blood of piglets of the control group remained high after weaning. Along with a decrease in the activity of the humoral link of immunity in weaned piglets, suppression of the non-specific link of the immune system was established, manifested by a decrease in phagocytic activity and a decrease in the number of phagocytes. Feeding the feed supplement “Sylimevit” to the piglets of the research group helped to strengthen the immune status of the piglets' bodies. In piglets of the research group on the 35th day of life, when feeding the feed additive “Sylimevit”, an increase in the phagocytic activity of neutrophils by 4.26 % was established. Similar differences were obtained regarding the effect of the Butaselmevit-plus feed additive on the phagocytic number and the phagocytic index, in particular, in piglets of the experimental group on the 35th day of the experiment; they were 7.63 and 11.1 % higher than in control. These research results confirm the effectiveness of using milk thistle, methifen, selenium, and vitamins as part of the feed supplement “Sylimevit” for piglets before and after weaning to activate the protective systems of their body

    Assessment of Blast Furnace Slag Transformation into Value Added By-Products on Basis on Knowledge of Slag Characteristics

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    Slags are the main by-products generated during iron and crude steel production and the steel industry is committed to increasing and improving their recycling. Today the quantity of slag produced and its utilization are one of the important indicators of sustainable steel industry. There are different forms of BF slag by-products depending on the method used to cool the molten slag. The byproducts can be an excellent source of constructional materials, finding applications in road building, concrete aggregate, as thermal insulation (mineral wool), and as a clinker substitute in cement production, biological filter media, glass making etc. In addition to products obtained from fresh slag, the possibility to utilize the old and the stockpiled blast furnace slags was studied. A key role in their utilization plays the knowledge of the chemical, mineralogical, and morphological properties of BF slag. This paper summarizes the characteristics of BF slag and its possible application

    An Overview of Assessment of the Blast Furnace Slag Transformation into Value Added by-Products on Basis of its Characteristics Knowledge

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    The slags are the main by-products generated during iron and crude steel production and the steel industry is committed to increasing and improving their recycling. Today the quantity of slag produced and its utilization are one of the important indicators of sustainable steel industry. There are different forms of BF slag by-products depending on the method used to cool the molten slag. The byproducts can be an excellent source of constructional materials, finding applications in road building, concrete aggregate, as thermal insulation (mineral wool), and as a clinker substitute in cement production, biological filter media, glass making etc. In addition to products obtained from fresh slag, was studied the possibility to utilize the old and the stockpiled blast furnace slags. The knowledge of the chemical, mineralogical, and morphological properties plays an essential key role in the utilisation of old and stockpiled blast furnace slags. This paper summarizes the characteristics of BF slag and its possible application

    Avaliação da carbonatação em pilares de concreto armado em garagens: estudo de caso

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    Esse trabalho trata de um estudo sobre a carbonatação natural do concreto em garagens. E, tem a intenção principal de medir e avaliar a frente de carbonatação das estruturas de concreto armado na cidade de Brasília, por meio de estudo de caso. Trata-se de garagens com características diferentes, levando em consideração a idade do concreto, umidade relativa do ar, umidade do concreto, concentração de CO2 e temperatura. O procedimento consiste em romper o concreto de cobrimento dos pilares, e medir a profundidade carbonatada, por entender que em garagens há uma maior concentração de dióxido de carbono. Os resultados foram analisados considerando-se uma série de fatores, inclusive os ambientais, que influenciam profundidade de carbonatação, como revestimentos contidos nos pilares. Foi empregado um modelo matemático de previsão de vida útil para carbonatação para estimar a vida útil dessas estruturas. Observou-se a maior frente de carbonatação ocorreu para o prédio mais novo, porém com maior teor de CO2. As garagens que possuíam revestimentos mais espessos nos pilares, como argamassa ou camada de pintura texturizada, percebeu-se que esses revestimentos, de fato, dificultaram a difusão do CO2 através do concreto

    Specific Performance and the Thirteenth Amendment

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    The role of the alumina content of slag, plus the presence of additional sulfate on the hydration and microstructure of Portland cement-slag blends

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    The effects on composite cements of the aluminium content of slag, plus that of additional sulfate, have been investigated. Samples containing cement or composites with 40% replacement by one of 2 different slags, differing in aluminium contents, were prepared. A further blended sample was prepared with additional anhydrite replacing 3% w/w of binder. Slag blended mortars showed comparable strengths to the neat cement system at later ages. Adding slag changed the hydration kinetics of the clinker phases. The addition of sulfate had no effect on slag reactivity but increased that of alite. Slags richer in aluminium resulted in greater incorporation of aluminium into C-S-H and encouraged the presence of hemicarboaluminate over monocarboaluminate. The Ca/Si ratios of the C-S-H formed were comparable between the two blends, being marginally lower than that of the neat system. The addition of anhydrite resulted in the adsorption of sulfate onto the C-S-H, plus stabilisation of ettringite
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