Production of threads with taps

Tato diplomová práce se zabývá studiem procesu výroby závitů závitníky, a to od samotného popisu jednotlivých závitů, přes všechny dostupné metody výroby závitů, kontrolu funkčnosti závitů, až po samotné závitníky, materiály, povlaky a jejich rozdělení. V experimentální části se práce zabývá otázkou, zda-li je možno nalézt alternativu k standardní výrobě závitů pomocí řezání závitníky. Touto alternativou se zdá být použití tvářecích závitníků. Experiment probíhal za konstantních řezných podmínek a skládal se ze dvou částí, jedna byla výroba závitů do předvrtaných průchozích děr a druhá byla výroba závitů do předvrtaných neprůchozích děr. Výsledkem experimentu bylo zjištění průběhu řezného momentu v závislosti na čase a velikost opotřebení zkoumaných druhů závitníků, kdy všechny naměřené hodnoty bylo potřeba statisticky zpracovat a poté vyhodnotit závěry.This thesis deals with the study of production process of threads by screw-taps from the very description of the individual threads through all the available methods of the threads production, thread control function, up to the actual taps, materials, coatings and their distribution. In the experimental part the thesis deals with the question whether it is possible to find an alternative to the standard production of threads using cutting by taps. This alternative seems to be the use of forming taps. The experiment took place under constant cutting conditions and consisted of two parts, one of them was the production of threads into the pre-drilled through holes and the second one was the production of threads into the pre-drilled impassable holes. The result of the experiment was finding the course of the cutting moment depending on the time and the amount of wear of the examined kinds of taps when all the measured values had to be statistically processed and conclusions were then evaluated.

Design of Feed and Water Dispenser for Dogs

Import 02/11/2016Bakalářská práce se zabývá návrhem dávkovače krmiva a vody pro psy. V úvodu jsou navrženy a následně srovnány koncepty. Na základě srovnání navržených konceptů je vybrán jeden, který nejlépe splňuje požadované parametry. Dále jsou detailně navrženy a zvoleny veškeré součásti dávkovače krmiva a vody pro psy. Při navrhování jednotlivých součástí je brán ohled na použití přístroje ke styku s potravinami a k provozu přístroje ve venkovních prostorách.Bachelor thesis is dealing with feed and water dispenser for dogs. The introduction is about designe and comparing concepts. Based on a comparison of the proposed concepts is selected the best which suits to required parameters. After that details are designed and selected all components dispenser feed and water for dogs. There were taken attention to using machine for contact with food and to operate outdoors.340 - Katedra výrobních strojů a konstruovánívýborn

Modification of a Device Designed to Remove Excess Weld

Diplomová práce se zabývá úpravou zařízení určeného k odstranění přebytečného svaru. V úvodu je analyzováno zařízení na odstranění přebytečného svaru, popsána jeho funkce a současný stav. Dále jsou analyzovány příčiny nedostatečné kvality odstranění svaru. Poté jsou určeny parametry při odstraňování, jako jsou rozměry prstence vůči rozměrům stroje, rozměry a teplota výronku svaru. Podle těchto vstupních informací jsou navrženy varianty řešení a vhodná varianta je podrobně rozpracována.Thesis is dealing with modification of a device designed to remove excess weld. The introduction is analyzed device designed to remove excess weld, function of this device is described and current state of this device is described. After that the causes of insufficient weld removal quality are analyzed. Then the removal parameters are determined, like dimensions of the ring relative to the dimensions of the machine, dimensions and temperature welding cap. Based on this input information solution variants are designed and a suitable variant is developed in detail.340 - Katedra výrobních strojů a konstruovánívelmi dobř

Soil quality effects on Chenopodium album flavonoid content and antioxidant potential

Antioxidant capacity, total phenolic content and flavonoid glycosides profile were compared in C. album samples grown in intensively cultivated (IC) and nondisturbed (ND) soils to evaluate differences in their nutraceutical potential. Petroleum ether, methanol, and aqueous extracts were sequentially obtained from C. album dried samples. Methanol crude extract exhibited the highest antioxidant potential and phenolic content, which were significantly enhanced by soil deterioration. This feature was enhanced in its ethyl acetate/n-buthanol subextract that also yielded higher amounts of the fraction containing flavonoid glycosides in samples grown in IC soils. Compounds were isolated by activity-guided fractionation, and chemical structure−antioxidant activity relationships were established. Chemical structures were elucidated by chemical and spectroscopic methods. Six known flavonoid glycosides were isolated, and their antioxidant activity was determined by DPPH assay. 1, quercetin-3-O-(2′′,6′′-di-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside; 2, kaempferol-3-O-(2′′,6′′-di-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside; 3, quercetin-3-O-β-d-glucopyranosyl-(1′′′→6′′)-β-d-glucopyranoside; 4, rutin; 5, quercetin-3-O-β-d-glucopyranoside; and 6, kaempferol-3-O-β-d-glucopyranoside. Triosides 1 and 2 were identified for the first time in C. album. Our results suggest that this edible weed, ubiquitously present in cultivated fields, should be considered as a nutraceutical food and an alternative source for nutrients and free radical scavenging compounds, particularly when collected from cultivated fields that seem to increase some of its advantages.EEA San PedroFil: Chludil, Hugo D. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos. Cátedra de Química Orgánica; ArgentinaFil: Corbino, Graciela Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Leicach, Silvia R. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos. Cátedra de Química Orgánica; Argentin

Bioactive compounds of two orange-fleshed sweet potato cultivars (Ipomoea batatas (L.) Lam.) in fresh, stored and processed roots

Sweet potatoes are a rich source of bioactive compounds, which are considered to promote human health. This study aimed to analyse the main bioactives of two orange-fleshed sweet potato cultivars, Beauregard and Colorado INTA, freshly harvested, after storage, and after processing of sweet potato paste, a solid dessert widely consumed in Argentina. In the flesh, phenolic compounds, carotenoids, anthocyanin contents, and radical scavenging activity were significantly higher in Colorado INTA cultivar. The carotenoid contents were 555 and 712 µg β-carotene/g dw in the flesh of Beauregard and Colorado INTA, respectively. In the peel of both cultivars, phenolic contents and antioxidant activities were notably higher than in the flesh. Extended storage has markedly increased phenolics and antioxidant properties in the flesh of Colorado INTA, further accentuating the differences between both cultivars. Paste processing negatively affected all parameters, particularly in Beauregard. The major phenolic compounds in both cultivars, chlorogenic and 3,5-dicaffeoylquinic acids, were the most affected by processing. The main reductions of bioactives stemmed from sugar addition. The inclusion of the peel, traditionally discarded during processing, could confer an additional value to the paste. The high bioactive contents of Beauregard and Colorado INTA cultivars, especially the latter, can contribute to provide health benefits and to reduce vitamin A deficiency. The valuable attributes of these cultivars could represent a useful tool for sweet potato producers to add value to this product and to foment its consumption.EEA San PedroFil: Gabilondo, Julieta. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Corbino, Graciela Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Corbino, Graciela Beatriz. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Química de Biomoléculas; ArgentinaFil: Chludil, Hugo Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; ArgentinaFil: Chludil, Hugo Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Parque Científico y Tecnológico; ArgentinaFil: Malec, Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento Química Orgánica; Argentin

Insecticidal activity of young and mature leaves essential oil from <i>Eucalyptus globulus</i> labill. against <i>Tribolium confusum</i> Jacquelin du val (Coleoptera: Tenebrionidae)

The confused flour beetle, Tribolium confusum Jaquelin Du Val, 1868, is a common pest insect known for attacking and infesting stored flour and grain. Biodegradable and ecologically natural products such as essential oils are emerging candidates for replacement of usually applied chemical pesticides. This work reported the chemical composition and effects caused by young and mature leaves essential oils (EOs) from Eucalyptus globulus Labill. against T. confusum. For both oils, no significant differences between yields were observed, being 1,8-cineole the main common constituent. Mature leaves extracts were rich in oxygenated mono- and sesquiterpenes, whereas young leaves showed greater content of nonoxygenated compounds. Bioassay was performed using EOs and 1,8-cineole solutions at different concentrations and time intervals. Adult mortality increased according to concentration and exposure time; young leaves extracts exhibited the greater effectiveness, highest mortalities (31.67%) at the minor time (2 h). At the lowest concentrations, 1,8-cineole solutions and mature leaves EOs did not achieve 100% mortality even when the bioassay was concluded (12 h), while at major doses no insects were alive. These results suggested that young and mature EOs from E. globulus constitute an alternative natural product to the control of T. confusum, since young leaves extracts, rich in monoterpene and sesquiterpene hydrocarbons, may be potential eligible candidates considering their noticeable insecticidal effects at low applied concentrations and short times of exposure.Facultad de Ciencias Naturales y Muse

Insecticidal activity of young and mature leaves essential oil from <i>Eucalyptus globulus</i> labill. against <i>Tribolium confusum</i> Jacquelin du val (Coleoptera: Tenebrionidae)

The confused flour beetle, Tribolium confusum Jaquelin Du Val, 1868, is a common pest insect known for attacking and infesting stored flour and grain. Biodegradable and ecologically natural products such as essential oils are emerging candidates for replacement of usually applied chemical pesticides. This work reported the chemical composition and effects caused by young and mature leaves essential oils (EOs) from Eucalyptus globulus Labill. against T. confusum. For both oils, no significant differences between yields were observed, being 1,8-cineole the main common constituent. Mature leaves extracts were rich in oxygenated mono- and sesquiterpenes, whereas young leaves showed greater content of nonoxygenated compounds. Bioassay was performed using EOs and 1,8-cineole solutions at different concentrations and time intervals. Adult mortality increased according to concentration and exposure time; young leaves extracts exhibited the greater effectiveness, highest mortalities (31.67%) at the minor time (2 h). At the lowest concentrations, 1,8-cineole solutions and mature leaves EOs did not achieve 100% mortality even when the bioassay was concluded (12 h), while at major doses no insects were alive. These results suggested that young and mature EOs from E. globulus constitute an alternative natural product to the control of T. confusum, since young leaves extracts, rich in monoterpene and sesquiterpene hydrocarbons, may be potential eligible candidates considering their noticeable insecticidal effects at low applied concentrations and short times of exposure.Facultad de Ciencias Naturales y Muse

Long-term legacy of land-use change in soils from a subtropical rainforest: Relating microbiological and physicochemical parameters

Tropical and subtropical ecosystems are widely affected by the expansion of agriculture over pristine lands. Despite research efforts, knowledge of the impact of land-use change on soil is still limited by intrinsic variability, inconsistent results and inadequate replication. This study aimed to better understand the consequences of land-use change by focusing on long-term effects on both soil biotic and abiotic parameters. For this purpose, we selected three productive farms under similar management, each of them with pristine forest sites and agricultural sites that had been deforested for ~15 and ~30 years. In each site, we analysed soil microbiological (phospholipid fatty acids [PLFAs], biomass and activity) and physicochemical parameters. Long-term land-use change caused a detriment in soil microbial biomass, activity and fungal abundance, but only small changes in PLFA composition. In fact, PLFA composition was more affected by soil physicochemical properties such as carbon-to-nutrient ratios and labile carbon than by land use. Some physicochemical parameters (e.g., organic carbon and nutrients) were also negatively affected by land-use change and were more sensitive to time under agricultural use than microbiological parameters. The lower sensitivity of microbiological parameters could be the result of severe drought conditions at sampling, which may have affected soil microbial communities in both land uses. We were also able to detect associations between specific microbiological and physicochemical parameters. Among these, we identified some that seemed to result from their co-variation in response to land-use change and others that seemed to be independent of land use. Overall, our results show that soils can suffer further deterioration several years after deforestation. In order to restore soil health in these degraded lands, we need to keep on investigating the physical, chemical and biological mechanisms responsible for this deterioration. Highlights: Land-use change affected soil microbiological and physicochemical parameters. Microbiological parameters seemed to stabilize after continuous agriculture. Soil organic C, total N and fine particles were still reduced after long-term cultivation. Microbiological parameters were mostly associated with C-to-nutrient ratios and labile C. Drought conditions may have affected microbial response to land-use change.Fil: Tosi, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Chludil, Hugo Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Biología Aplicada y Alimentos; ArgentinaFil: Correa, Olga Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Vogrig, Jimena Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Montecchia, Marcela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Estudios preliminares sobre compuestos antioxidantes en materiales clonales del programa de mejoramiento genético de sauce del INTA

En la Estación Experimental Agropecuaria (EEA) INTA Delta del Paraná se desarrolla un programa de mejoramiento clásico de sauces, en el marco del Proyecto Nacional PNFOR- 1104062 y del Programa de Domesticación y Mejoramiento de Especies Forestales Nativas e Introducidas para Usos de Alto Valor (PROMEF). El objetivo es generar materiales clonales con ventajas productivas y de adaptabilidad. En el corriente año, seis nuevos clones mejorados fueron inscriptos en el Registro Nacional de Cultivares del INASE: `Agronales INTA-CIEF´, `Los Arroyos INTA-CIEF´, `Géminis INTA-CIEF´, `Lezama INTA-CIEF´, `Ibicuy INTA-CIEF´ y `Yaguareté INTA-CIEF´. Desde hace unos años, docentes investigadores de la Facultad de Agronomía de la UBA colaboran a través de un trabajo interdisciplinario con el Programa, analizando el material clonal a fin de evaluar características químicas que contribuyan a explicar los mecanismos implicados en ciertos comportamientos frente a situaciones de estrés biótico y abiótico, a los cuales naturalmente se ven sometidos. Las investigaciones se realizan en el marco de los proyectos UBACyT (2012-2015) 20020110200266 y UBACyT (2011-2014) 20020100100229. El presente trabajo comprende un análisis preliminar de los compuestos antioxidantes presentes en individuos de Salix spp. Los derivados fenólicos son metabolitos secundarios de amplia distribución en las plantas superiores, y particularmente los sauces se caracterizan por la presencia de glicósidos fenólicos y salicilatos los cuales constituyen una verdadera barrera de defensa y resistencia a adversidades. En esta primera etapa exploratoria se trabajó con clones de las especies Salix nigra, S. alba, S. humboldtiana, S. viminalis y S. matsudana, de los cuales se tomaron tres repeticiones y se analizaron, mediante métodos espectrofotométricos, su capacidad antioxidante (CA) y el contenido de fenoles totales (FT) expresados como moles equivalentes de ácido ascórbico y moles equivalentes de ácido clorogénico /g de hojas frescas, respectivamente. Los resultados de este trabajo exploratorio muestran que los clones recientemente registrados poseen diferencias contrastantes en cuanto a contenidos de CA y FT. Los valores de CA, en orden decreciente, corresponden a: Lezama > Yaguareté, Geminis > Ibicuy, Agronales y Los Arroyos. Respecto al contenido de FT, se observa el mismo orden decreciente presentando Lezama un valor de 186 moles eq ác. clorogénico /g de hojas frescas. Mediante HPLC-C18 se compararon los perfiles cromatográficos entre clones de una misma especie y especies diferentes observándose importantes variaciones entre los materiales. Estas observaciones preliminares aportan conocimientos que podrían ayudar a comprender aspectos de la susceptibilidad de los clones a las adversidades y los mecanismos implicados.EEA Delta del ParanáFil: Pagano, Natalia. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Química de Biomoléculas; ArgentinaFil: Cerrillo, Teresa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; ArgentinaFil: Leicach, Silvia Rosa. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Química de Biomoléculas; ArgentinaFil: Chludil, Hugo Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Química de Biomoléculas; Argentin