Metodología para el control del temple y el acabado de componentes de precisión endurecidos mediante grind-hardening

270 p.

Effect of low-calcium diet and grind diet on bone turnover of ovariectomized female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic and Malt Quality Diversity of East Asian Two-Rowed Barley Accessions in Relationship to North American Malting Barley.

Because of epidemics of Fusarium head blight (FHB; caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.) Petch]) in the northern Great Plains of the United States and Canada in the past two decades, malting barley breeders have been forced to use nonadapted barley (Hordeum vulgare L.) accessions as sources of FHB resistance. Many of the resistant accessions are from East Asia, and limited information is available on their genetic diversity and malt quality. The objectives of this study were to determine the genetic diversity among 30 East Asian accessions and two North American cultivars. Genetic diversity was based on 49 simple-sequence repeat markers. All accessions were tested for barley grain brightness; protein content; 1,000-kernel weight; malting loss; fine-grind malt extract; content of plump kernels, free amino nitrogen, soluble protein, and wort beta-glucan; the Kolbach index (i.e., the ratio of malt soluble protein to malt total protein); a-amylase activity; diastatic power; won color; and wort viscosity. A few accessions had equal quality compared with Harrington and Conlon barley for individual traits but not for all. Qing 2, Mokkei 93-78, and Nitakia 48 could be excellent sources for increased malt extract; Nitakia 48 is a possible source for low wort viscosity; and Mokkei 93-78 and Nitakia 48 are putative sources of low beta-glucan content. The cluster analyses also implied that the malt quality of an accession cannot be predicted based on the country where it was developed.

Reverse flotation of silica from Kudremukh iron ore .2. Optimization of flotation process

An experimental programme based on statistical analysis was used for optimizing the reverse Rotation of silica from non-magnetic spiral preconcentrate of Kudremukh iron ore. Flotation of silica with amine and starch as the Rotation reagents was studied to estimate the optimum reagent levels at various mesh of grind. The experiments were first carried out using a two level three factor design. Analysis of the results showed that two parameters namely, the concentration level of the amine collector and the mesh of grind, were significant. Experiments based on an orthogonal design of the hexagonal type were then carried out to determine the effects of these two variables, on recovery and grade of the concentrate. Regression equations have been developed as models. Response contours have been plotted using the 'path of steepest ascent', maximum response has been optimized at 0.27 kg/ton of amine collector, 0.5 kg/ton of starch and mesh of grind of 48.7% passing 300 mesh to give a recovery of 83.43% of Fe in the concentrate containing 66.6% Fe and 2.17% SiO2.

Survey of biosystematic and sexual reproductive physiology in Holothuroidea on Hormozgan Province

Sea cucumbers belong to phylum Echinodermata, order Holothuroidea are an abundant and diverse group of Invertebrates, with over 1400 species occuring from the intertidal to the deepest oceanic trenches. Sea cucumbers are important components of the food chain in temperate and coral reef ecosystems and they play an important role as deposite feeders and suspension feeders. Rapid decline in populations may have serious consequences for the survival of other species that are part of the same complex food web,as the eggs, larve and juveniles constitute an important food source for the other marine species including crustaceans, fish and mollusks. In addition sea cucumbers are often called the earthworms of the sea, because they are responsible for the extensive shifting and mixing of the substrate, and recycling of detrital matter. Sea cucumbers consume and grind sediment and organic material into finer particles , turning over the top layers of sediment in lagoons , reefs and other habitats and allowing the penetration of oxygen. While the taxonomy of the holothurian families is generally well known , the distinction of similar species is difficult. There are relatively few holothurian taxonomist.Most sea cucumber species can be identified by Holothurin taxonomists by using the calcareous skeletal ossicles found in the body wall. In this study , at first a sea cucumber from Kish island in Persian gulf has recognized. Individuals collected from west and east extend far away into north and south of coral reefs by diving. I have checked them morphologically and anatomically.Then with key to the orders of the Holothuroidea, They belong to the Aspidochirotida with key to the families of Aspidochirotida, they were in Stichopodidae families and with key to the genus of Stchopodidae, they were Stichopus. Then ossicles were extracted at National Museum of Natural History, by Dr David Pawson. The ossicles were measured on a transect across a slide prepared from the mid-dorsal region of each specimen.The one we have in the shallow waters of Kish island, is Stichopus hermanni, a massive holothurian, body broad, considerably flattened ventraly ,the dorsal side slightly arched and the lateral sides almost vertical; body wall fairy thick and soft ; mouth subterminal; anus central; tentacles usually 20 in number of length and leaf shaped. Numerous ossicles consisting of table with large discs having usually 7 to 15 peripheral holes, but often irregular or incomplete and spire of moderate height ending in a group of spinelets, rosettes of variable development, and c-shaped rods. Color (exept papillae)partly remained after preservation in alcohol which is found at the depth of 4 to 8 meters, on coral reef. Furthermore, the sexual reproductive cycle was described using standard methods. Gonads were removed and transferred to Bouin's fixative for four weeks and then processed according to standard embedding technique. To prevent the loss of tubule contents during embedding, the tubule sections, were cut well beyond the segment selected for sectioning. For each individual, six sections, each section with 5µm diameter by microtome were cut from tubules. These sections were first placed on gelatin coated slides (the gelatin was heated to 42°c) and then transferred to the oven at 37°c for one hour. This technique usually prevents the fragil tubules from breaking and the loss of gametes. The slides were stained with Eosin and Hematoxylin, and good resolution of the various cell types achieved.A second series of slides was stained with the Periodic Acid Schiff(PAS) to identify polysaccharides(glycogen). Monthly sampling was occurred.The sexual reproductive cycle was defined through the combined use of these criteria: Monthly percentages of the gonad stages for each sex, the monthly gonad index (GI) , given as the ratio of the wet gonad weight (G) to the dray weight (DW)and the monthly percentage of individuals that undetermined sex. The gonad consists of two tufts of tubules on which saccules develop. Gonadal development was classified into five stages: post spawning, recovery, growth, advanced growth, and mature stage that were adapted from the earlier studies of holothurians. Histological preparations showed that the sex of larger individuals could be identified by the presence of oogonia and young oocytes in females, and spermatogonic stages in males.The mean diameter of the tubules and gonadal mass follow annual cycles, increasing from late winter through spring, and dropping abruptly after spawning in the summer. Gametogenesis is generally a prolongate process and begins in March. By summer the ovarian tubules contain oocytes with diameter of 120-240 pm and the testicular tubules contain an abundance of spermatozoa (diameter 5-6 gm ).Following spawning the predominant activity within the spent tubules is phagocytosis of the residual gamets.The active phase of gametogenesis (March to July), coincides with an increasing photoperiod regim, and an accelerated gametogenesis occurs in July when temperature is high. Throughout the year, the gonad of Stichopus hermanni is larger in males than in females, and this is due to the number of tubules in the testis rather than to tubules length or diameter.

Fabrication and characterisation of high resistivity SOI substrates for monolithic high energy physics detectors

Silicon on Insulator (SOI) substrates offer a promising platform for monolithic high energy physics detectors with integrated read-out electronics and pixel diodes. This paper describes the fabrication and characterisation of specially-configured SOI substrates using improved bonded wafer ion split and grind/polish technologies. The crucial interface between the high resistivity handle silicon and the SOI buried oxide has been characterised using both pixel diodes and circular geometry MOS transistors. Pixel diode breakdown voltages were typically greater than 100V and average leakage current densities at 70 V were only 55 nA/ sq cm. MOS transistors subjected to 24 GeV proton irradiation showed an increased SOI buried oxide trapped charge of only 3.45x1011cn-2 for a dose of 2.7Mrad

Something to show for it: the place of mementoes in women’s oral histories of work

Workplace memorabilia, regarded here as artifacts and mementoes kept from workplaces and stored in homes, is varied, including; tools of a trade, ephemeral leaflets and pamphlets, union mementoes, uniforms and badges, long service awards, gifts from colleagues, and photographs both formal and informal. These objects can symbolize many years of work-life history and the corollary of this, their absence, perhaps the need to forget the drudgery of ‘the daily grind’. The materiality of an object saved or taken from the workplace often prompts reminiscence (Bornat, 2001) but can also, in itself and its method of display, represent and express key identities, work processes and traditions. Using examples from a three year ESRC funded project on work and identity this paper focuses on the women who participated in the study and investigates what is kept or not, whether the ways in which work memorabilia is displayed or stored is gendered, and how this might illuminate gendered social relations in the workplace and gendered work identities.

Carretera salvaje acarreo de un par de vidas

La presente investigación ilustra el desenvolvimiento general de los viajes de los camioneros minoristas, es decir, aquellos que poseen hasta tres camiones, son conductores de camiones ajenos, y que deben conseguir la carga por medio de sus propios contactos. Los testimonios revelan el día a día de los camioneros, el ajetreo cotidiano y las vicisitudes particulares que se viven en el país. Las rutas colombianas son el escenario de las historias a partir de los testimonios de Segundo García y Fernando Díaz, dos experimentados conductores de camión que, desde su perspectiva de transportadores minoristas, han tenido la oportunidad de percibir acontecimientos que se han escapado al ojo de los medios masivos de comunicación. Crónicas que ilustran una realidad desconocida para muchos.

Evaluación y Análisis de las oportunidades del subsector panelero frente al Tratado de Libre Comercio con la Unión Europea

El presente trabajo de investigación es un análisis de las oportunidades que tiene el subsector panelero colombiano como agente exportador, haciendo un énfasis especial en el Tratado de Libre Comercio de Colombia con la Unión Europea. Se pretende así, determinar las estrategias que pueden ser implementadas para que este subsector panelero se organice como gremio y así pueda obtener oportunidades de mercado con la Unión Europea. Para el desarrollo de este trabajo se hizo una investigación sobre la producción de panela en términos porcentuales de Colombia, así como de la participación de cada una de las regiones. Así mismo se hace un análisis de la asociatividad y la competitividad de este subsector.

Asparagus: a horticultural ballet

Asparagus: A Horticultural Ballet was a live performance and film narrating the rise of capital in the medium of asparagus. The project stemmed from an obscure reference to an art piece of the same name by Waw Pierogi of the band xex. However, the its re-enactment had little to do with the original exploration of the growth and branching patterns of the asparagus plant. Instead, a rigid choreography inspired by Oskar Schlemmer's Triadic Ballet and based on Karl Marx's Capital dictated the movements of six performers in asparagus costumes. Bringing together the organic and the geometric, the ballet investigated the transition from the Fordist assembly line to immaterial labour through a reanimation of modernist abstraction. Being itself the story of abstraction, Capital shows how human relationships are replaced by those between commodities in the joyless grind of endless accumulation. This process results in the transcendent mythical figure of capital, which frames, transfigures and even produces the natural world. Asparagus: A Horticultural Ballet was produced in collaboration with Montreal based band Les Georges Leningrad and commissioned by The Showroom Gallery, London. It was presented live at Conway Hall in London on 6.3.07 and at the Montreal Biennale at SAT on 12.5.07. The performance was accompanied by a film at the Showroom gallery and preceded by a production residency at the Pump House Gallery. The film has subsequently been shown at The Golden Thread Gallery, Bluecoat Liverpool and as part of A-Lot-Ment in Portsmouth. Props from Asparagus: A Horticultural Ballet, were included in The Eagle Document at the Stephen Lawrence Gallery, London.

Electromyographic activity of the mandible muscles at the beginning and end of masticatory cycles in patients with complete dentures

The aim of this study was to assess the electrical activity of the masseter and anterior temporal muscles in subjects with severe bone resorption at two different times: ( a) the initial period, with the complete dentures they had worn for over 10 years, and (b) the final period, 5 months after having new dentures put into place. Twelve asymptomatic subjects were asked to respond to the questionnaire, according to the research diagnostic criteria for temporomandibular disorders, before denture rehabilitation and 5 months after the new dentures were put in place. The electrical activity of the muscles was recorded during mastication in the initial and final period, using artificial food (Optocal). The operator monitored the 35 chewing cycles that were repeated to grind the artificial food. After wearing the new dentures for 5 months, the right anterior temporal muscle showed a statistical difference before and after denture rehabilitation at the beginning and end of mastication. Muscular capacity and ability reduced the electrical activity in the masseter muscles after rehabilitation. Copyright (c) 2008 S. Karger AG, Basel.

Silent Period of Masticatory Cycles in Dentate Subjects and Complete Denture Wearers

Purpose: The purpose of this study was to assess, through electromyographic activity (EMG), the silent period (SP) of masseter and anterior temporal muscles in dentate subjects (DS) and complete denture wearers (CDW).Materials and Methods: The evaluations were performed at the initial and final period of the mastication for the DS group. For the CDW group, the evaluations were performed at the initial period of mastication, with old complete dentures worn for more than 10 years (OCDW) and at the final period of the mastication with new complete dentures (NCDW), 5 months after rehabilitation. Twenty-four asymptomatic subjects (12 DS, 12 CDW) answered a questionnaire based on the Research Diagnostic Criteria for temporomandibular disorders. The CDW group answered the questionnaire before and after new denture insertion and after 5 months of rehabilitation. The SP of the muscles was recorded through EMG at the initial and final periods of mastication using artificial food (Optocal). The operator monitored 35 chewing cycles performed to grind the artificial food and selected eight open-close-clench-chewing cycles for the record.Results: The SP of the muscles analyzed with new complete dentures showed no statistical difference in comparison to the old dentures. There was a statistically significant difference in the SP between the CDW and DS groups for initial and final chewing.Conclusion: Lowered muscular capacity and ability reduced the SP of muscles after rehabilitation with NCDWs.

Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo comparativo do desempenho de rebolos com grãos superabrasivos e convencionais

Grinding is a precision machining process which is widely used in the manufacture of components requiring fine tolerances and smooth surfaces. There are several imput parameters (cutting conditions, cutting fluid and grinding wheel type used, dressing conditions etc.) which can affect the process variables (tangential and normal cutting forces, roughness, grinding temperatures, G ratio, etc.) leading to differences in the roughness, in the surface integrity and in the mechanical strength of the ground component. Consequently, the imput parameters must be controlled in order to insure the workpiece final quality. This paper presents a comparative evaluation of the performance of two types of grinding wheels [a conventional (Al2O3) and a superabrasive (CBN)] when grinding a VC131 steel, by the analysis of specific process variables when varying the cutting conditions. Highest values of G ratio and lowest workpiece roughness was observed when using CBN grinding wheels. This confirms the global trend of replacement of alumina grinding wheels by CBN, when grinding DTG (difficult to grind) materials.