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Sample records for pregrazing herbage mass

  1. Fatty acid intake and rumen fatty acid composition is affected by pre-grazing herbage mass and daily herbage allowance in Holstein dairy cows

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    Rafael A. Palladino

    2014-07-01

    Full Text Available The objective of this study was to investigate the effect of level of pre-grazing herbage mass (HM and daily herbage allowance (DHA on the fatty acid (FA intake and composition of ruminal content of grazing dairy cows. Four rumen fistulated Holstein-Friesian dairy cows were allocated to either a high or low HM (1700 vs 2600 kg DM ha-1 and within herbage mass treatment further allocated to a high or low DHA (20 vs 16 kg of DM cow-1 day-1 in a 4 × 4 Latin square design. Total FA intake and linolenic acid (LNA intake was higher for cows on high DHA (p<0.05. Ruminal oleic acid, linoleic and LNA were not affected by treatments. Ruminal stearic acid (C18:0 and vaccenic acid (VA concentrations were higher at low HM (43.6 and 14.8 g/100 gof FA respectively; p<0.01 compared to high HM (42.0 and 12.5 g/100 gof FA respectively for C18:0 and VA. Cows grazing high DHA had higher ruminal concentration of VA (15.3 g/100 gof FA; p<0.01 than low DHA (12.1 g/100 gof FA. Regarding milk FA composition, only some of the milk FA varied across treatments, being the VA and LNA concentrations higher at low HM (p<0.05. These data suggest that low HM and high DHA, at least within the range studied here, promotes the accumulation of ruminal VA which could be available for subsequent conversion within the mammary gland to the human health promoting c9,t11 isomer of conjugated linoleic acid.

  2. Meta-analysis of the effect of pregrazing pasture mass on pasture intake, milk production, and grazing behavior of dairy cows strip-grazing temperate grasslands.

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    Pérez-Prieto, L A; Delagarde, R

    2012-09-01

    Grazing management is a key factor in pasture-based dairy systems, which can be improved given advanced knowledge of the effects of pregrazing pasture mass (PM) on the performance of dairy cows. The aim of this study was to quantify the effects of PM on the pasture intake, milk production, milk composition, and grazing behavior of strip- or rotational-grazing dairy cows, based on a meta-analysis of published research papers. A database was created that included experiments in which the effects of PM on pasture intake and milk production of dairy cows were studied. Papers were selected only if at least 2 PM were compared under similar experimental conditions, particularly the same pasture allowance (SPA). The final database included 15 papers with 27 PM comparisons. For analytical purposes, the database was subdivided into 3 subsets that varied according to the estimation height at which pasture allowance was determined; that is, where PM were compared at the SPA above ground level (SPA(0) subset), above 2 to 3 cm (SPA(3) subset), and above 4 to 5 cm (SPA(5) subset). Statistical analyses were conducted on the entire database (global analysis) and within each subset using linear model procedures. An interaction between PM and estimation height was found for pasture intake and milk production in the global analysis. On the basis of the predictive equations, pasture intake increased by 1.58 kg of dry matter/d per tonne increase in PM when PM were compared at SPA(0), was not affected by PM when PM were compared at SPA(3), and decreased by 0.65 kg of dry matter/d per tonne increase in PM when PM were compared at SPA(5). This is consistent with the effect of PM on milk production, which was positive and negative (1.04 and -0.79 kg/t of PM, respectively) when PM were compared at SPA(0) and SPA(5), respectively. Grazing time was only slightly affected by PM, irrespective of estimation height, because the effect of PM on pasture intake was mainly dependent on the variation

  3. Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação Herbage accumulation during regrowth of Xaraés palisadegrass submitted to rotational stocking strategies

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    Bruno Carneiro e Pedreira

    2009-04-01

    Full Text Available Objetivou-se comparar a dinâmica do acúmulo de forragem em pastos de capim-xaraés [Brachiaria brizantha (A. Rich. Stapf. cv. Xaraés] submetidos a três estratégias de desfolhação intermitente, uma baseada no calendário (pastejo a cada 28 dias e duas na interceptação luminosa (IL, aos 95 ou 100% de interceptação luminosa. A massa de forragem (MF pré-pastejo foi maior na estratégia de desfolhação aos 100% de interceptação de luz. Os piquetes pastejados aos 95% de interceptação de luz e a cada 28 dias apresentaram menores massas de forragem e não diferiram entre si na primavera. O pastejo aos 95% de interceptação de luz aumentou a proporção de folhas, apesar das menores massas pré-pastejo. O pastejo aos 100% de interceptação de luz resultou na menor porcentagem de folhas na massa de forragem, indicando que a maior produção total de forragem foi ocasionada pelo maior alongamento de colmos, o que está associado à competição por luz entre as plantas no interior do dossel. O prolongamento do período de descanso para além dos 95% de interceptação da luz incidente aumenta a massa de forragem na entrada dos animais no momento do pastejo (100% IL ou a cada 28 dias durante o verão, porém, esse aumento é resultado do acúmulo de colmos e material morto e pode afetar negativamente o valor nutritivo da forragem produzida e o desempenho animal.The objective of this research was to describe comparatively the dynamics of herbage accumulation in Xaraés palisadegrass pastures [Brachiaria brizantha (A. Rich. Stapf cv. Xaraés] submitted to rotational stocking managements, defined either by pre-graze light interception (LI by the canopy (95% or 100% LI or calendar days (28d. Pre-graze forage mass (FM was higher for 100% LI pastures. Pastures grazed at 95% LI and 28-d resulted in similar pre-graze FM in the spring, both lower than that of the 100%-LI treatment. Grazing at 95% LI resulted in higher leaf percentage in pre-graze

  4. Effect of the type of silage on milk yield, intake and rumen metabolism of dairy cows grazing swards with low herbage mass.

    Science.gov (United States)

    Ruiz-Albarrán, Miguel; Balocchi, Oscar A; Noro, Mirela; Wittwer, Fernando; Pulido, Rubén G

    2016-07-01

    The aim of this study was to evaluate the effect of herbage allowance (HA) and type of silage supplemented (TS) on milk yield, dry matter intake (DMI) and metabolism of dairy cows in early lactation. Thirty-six Holstein-Friesian dairy cows were allocated to four treatments derived from an arrangement of two HA (LHA = 17 or HHA = 25 kg of DM/cow/day) and two TS (grass (GS) or maize (MS)). Herbage allowance had no effect on DMI or milk yield. Rumen pH and NH3 -N concentration were not affected by HA. The efficiency of microbial protein synthesis in the rumen (microbial protein (MP)) was affected by HA with 21.5 and 23.9 g microbial nitrogen per kg ruminal digestible organic matter for LHA and HHA, respectively (P < 0.05). Supplementation with MS showed higher values of milk yield by 2.4 kg/cow/day (P < 0.001), milk protein content by 0.10 % (P < 0.023) and herbage DMI by 2.2 kg/cow/day, and showed lower values for milk urea compared to GS (P < 0.001). The former results suggest that TS had a greater effect on milk yield, total feed intake and energy intake than increase in herbage allowance; however, increase in HA had greater effects on MP than TS.

  5. Consumo de forragem e produção de leite de vacas em pastagem de azevém-anual com duas ofertas de forragem Herbage intake and milk yield of dairy cows grazing Italian ryegrass at two herbage allowances

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    Henrique Mendonça Nunes Ribeiro Filho

    2009-10-01

    Full Text Available Avaliou-se o efeito de duas ofertas de forragem (25 e 40 kg MS/vaca.dia sobre o consumo de forragem e a produção de leite em vacas pastejando azevém-anual. Utilizou-se o método rotacionado, em delineamento experimental de dupla reversão, com três períodos de 12 dias e dez vacas da raça Holandesa no terço médio de lactação. O consumo de forragem foi estimado pela produção fecal e pela digestibilidade da forragem ingerida e a produção de leite foi medida diariamente. A biomassa e a altura do dossel antes do pastejo não diferiram entre as ofertas de forragem. A altura pós-pastejo foi maior na oferta de forragem de 40 kg MS/vaca.dia, o que determinou desaparecimento de forragem equivalente a 49,0% nessa oferta de forragem e a 69,0% na oferta de 25 kg MS/vaca.dia. O consumo individual de matéria seca (MS da forragem foi 11,9 e 16,6 kg/dia e a produção de leite, 18,4 e 21,1 kg/dia nas ofertas de 25 e 40 kg MS/vaca.dia, respectivamente. Vacas leiteiras em pastagem de azevém com alta oferta de forragem podem ingerir mais de 16,0 kg de MS e produzir mais de 20 kg de leite/dia. A produção de leite reduz aproximadamente 0,2 kg a cada kg de diminuição na MS de forragem oferecida.The effect of two herbage allowances (25 and 40 kg dry matter/cow.day were assessed on the herbage intake and milk yield of dairy cows grazing Italian ryegrass. A rotational grazing system was used, according to a Change Over procedure with three 12-day periods and ten Holstein cows in mid-lactation. Individual herbage intake was estimated from fecal output and the digestibility of the selected herbage and the milk yield was measured daily. Pre-grazing sward height and herbage mass at ground level did not differ between treatments. Post-grazing sward height was higher 40 kg dry matter/cow.day and the pasture disappearance rate from the initial sward was 49.0% and 69.0%, respectively. The individual dry matter intake of the herbage was 11.9 and 16.6 kg kg

  6. Comportamento ingestivo e desempenho de ovinos em pastagem de azevém anual (Lolium multiflorum Lam. com diferentes massas de forragem Ingestive behaviour and performance of sheep grazing Italian ryegrass (Lolium multiflorum Lam. pasture with different herbage masses

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    Juliano Roman

    2007-08-01

    Full Text Available Objetivou-se avaliar o comportamento ingestivo e o desempenho de ovinos em pastagem de azevém anual (Lolium multiflorum Lam. sob pastejo contínuo e com diferentes massas de forragem: baixa: 1.000 a 1.200 kg/ha MS; intermediária: 1.400 a 1.600 kg/ha MS; alta = 1.800 a 2.000 kg/ha MS. O delineamento experimental foi inteiramente casualizado com três tratamentos e duas repetições de área. Os dados foram submetidos à análise de regressão polinomial em função das massas de forragem observadas nas unidades experimentais: 1.136,8; 1.190,9; 1.359,2; 1.375; 1.556 e 1.739,1 kg/ha MS. Os valores de massa de lâminas foliares e de pseudocolmo, de oferta de forragem e de lâminas foliares, de altura de dossel e de pseudocolmo, de profundidade de lâminas foliares e de ganho médio diário ajustaram-se ao modelo linear de regressão, relacionando-se positivamente com a massa de forragem. Os valores de taxa de lotação e de taxa de bocados diminuíram linearmente com o aumento da massa de forragem. O consumo de forragem, os tempos de pastejo, de ruminação e de ócio, o número diário de bocados, a massa de bocado, o ganho de escore de condição corporal, o ganho de peso vivo por área e a eficiência de conversão de forragem em peso vivo foram similares entre as massas de forragem avaliadas. As amplitudes de massas de forragem avaliadas não promovem diferenças no ganho de peso vivo por hectare, pois proporcionaram similar eficiência de transformação da forragem em produto animal. O principal fator determinante do desempenho individual dos animais é a profundidade da camada de lâminas foliares.The objective of this trial was to evaluate ingestive behaviour and performance of sheep grazing Italian ryegrass (Lolium multiflorum Lam. pasture with different herbage mass (HM: low HM: 1,000 - 1,200 kg/ha of DM (LHM; medium HM: 1,400-1,600 kg/ha DM (MHM; high HM 1,800-2,000 kg/ha DM (HHM. A completely randomized design with three treatments and

  7. Estrutura do pasto disponível e do resíduo pós-pastejo em pastagens de capim-cameroon e capim-marandu Pasture structure and post-grazing herbage mass in pastures of elephantgrass cv. Cameroon and palisadegrass cv. Marandu

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    Cláudia de Paula Rezende

    2008-10-01

    Full Text Available Avaliaram-se, em dois experimentos, as características estruturais e o teor de proteína bruta das forrageiras Pennisetum purpureum cv. Cameroon e Brachiaria brizantha cv. Marandu em pastagens submetidas a quatro taxas de lotação rotacionadas. No período das águas, as taxas de lotação impostas a ambas as pastagens foram de 3, 4, 5 e 6 novilhos/ha e, no período seco, de 2, 3, 4 e 5 novilhos/ha. Nos dois experimentos, o capim-cameroon apresentou maior massa de forragem total e massa de forragem verde, que decresceram com o aumento da desfolha imposta pelas taxas de lotação, principalmente no período seco. Nessa forrageira, o aumento da taxa de lotação comprometeu em maior intensidade a fração de matéria seca de lâmina foliar verde. No período das águas, as taxas de lotação que propiciaram maior oferta de massa seca de forragem total, forragem verde e fração de lâmina foliar foram as de 5 e 4 novilhos/ha, respectivamente, para os capins cameroon e marandu. No período seco, no entanto, os maiores valores obtidos para essas variáveis foram, respectivamente, de 4 e 3 novilhos/ha. As taxas de lotação não influenciaram o teor de proteína bruta das gramíneas, que foi maior no componente lâmina foliar verde da planta.Two experiments were carried out to evaluate structural characteristics and crude protein concentration of Pennisetum purpureum cv. Cameroon and Brachiaria brizantha cv. Marandu under four rotational stocking rates. During the rainfall period, the studied stocking rates for both pastures were 3, 4, 5, and 6 steers/ha and in the dry period the stocking rates were 2, 3, 4, and 5 steers/ha. In both experiments, elephantgrass cv. Cameroon produced greater total herbage mass and green herbage mass, which decreased with the increase in defoliation as a result of the used stocking rates, mainly during the dry period. For elephantgrass pastures, the increase in stocking rate had a greater negative effect on the green

  8. Effects of perennial ryegrass (Lolium perenne L.) cultivars on herbage production, nutritional quality and herbage intake of grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.; Tas, B.M.; Taweel, H.Z.; Tamminga, S.; Elgersma, A.

    2005-01-01

    Four perennial ryegrass (Lolium perenne L.) cultivars were compared for differences in herbage production, nutritive value and herbage intake of dry matter (DM) during the summers of 2002 and 2003. Two paddocks were sown with pure stands of four cultivars in a randomized block design with three repl

  9. Características estruturais e acúmulo de forragem em capim-tanzânia sob pastejo rotativo Structural characteristics and herbage accumulation of Tanzania guineagrass subjected to rotational stocking

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    Anderson de Moura Zanine

    2011-11-01

    characteristics and herbage accumulation of tanzania guineagrass (Panicum maximum cv. Tanzania under rotational grazing and subjected to combinations of two grazing frequencies (time for the canopy to intercept 90 or 95% of the incident light and two post-grazing heights (30 or 50 cm. Treatments were assigned to experimental units according to a 2 × 2 factorial arrangement in a completely randomized design, with three replications. Sward heights at pre-grazing were consistent during the experimental period and were of around 65 and 75 cm, for 90% and 95% of light interception (LI, respectively. Pastures managed with post-grazing height of 50 cm and 90% of LI had higher number of grazing cycles when compared with those submitted to post-grazing height of 30 cm and 95% of LI. Herbage mass production was higher in summer, intermediate in late spring and lowest in fall and winter and early spring. Herbage mass and lamina leaves production were higher in pastures managed with post-grazing height of 30 cm when compared with post-grazing height of 50 cm. Nevertheless, the effects of frequency on herbage mass production were associated with the post-grazing height used. The LI levels (90 or 95% did not affect leaf lamina production. The combinations of frequency and severity of grazing resulted in little variation in the morphological composition of forage, except in the autumn, when there was a higher percentage of dead material in pastures managed with post-grazing height of 50 cm when compared with those with post-grazing height of 30 cm. The rotational grazing of tanzania guineagrass should be initiated when canopy intercepts 95% of incident light until a post-grazing height of 30 cm. When necessary and in order to generate flexibility in grazing management, the tanzania guineagrass can be grazed with 90% of light interception.

  10. Estimating ice encasement tolerance of herbage plants.

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    Gudleifsson, Bjarni E; Bjarnadottir, Brynhildur

    2014-01-01

    One of the key stresses acting on herbage plants during winter is ice encasement, when plants are enclosed in compact ice and turn from aerobic to anaerobic respiration. The cause of cell death is related to the accumulation of metabolites to toxic levels during winter and perhaps also to production of reactive oxygen species (ROS) when plants escape from long-lasting ice cover. The process of ice encasement damage has been studied by sampling studies, indirect measurements of ice tolerance, field tests and provocation methods by increasing stress in the field artificially, thus increasing the ice stress. Here we describe a laboratory method to measure ice encasement tolerance. This is the most common and effective way to measure ice encasement tolerance of large plant material. Plants are raised from seeds (or taken from the field), cold acclimated, usually at +2 °C under short day conditions, in a greenhouse or growth chamber (or in the field during fall). Plants are submerged in cold water in beakers and frozen encased in ice, usually at -2 °C. Plants are kept enclosed in ice at this temperature. Samples are taken at intervals, depending on species and tolerance of plant material, and put smoothly to regrowth. Damage is then evaluated after a suitable time of regeneration.

  11. Comparison of techniques for estimating herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.; Taweel, H.Z.; Tas, B.M.; Tamminga, S.; Elgersma, A.

    2005-01-01

    For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage m

  12. Comparison of techniques for estimating herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.; Taweel, H.Z.; Tas, B.M.; Tamminga, S.; Elgersma, A.

    2005-01-01

    For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage

  13. Forage herbs improve mineral composition of grassland herbage

    DEFF Research Database (Denmark)

    Pirhofer-Walzl, Karin; Søegaard, Karen; Jensen, Henning Høgh

    2011-01-01

    Provision of an adequate mineral supply in the diets of ruminants fed mainly on grassland herbage can present a challenge if mineral concentrations are suboptimal for animal nutrition. Forage herbs may be included in grassland seed mixtures to improve herbage mineral content, although...... there is limited information about mineral concentrations in forage herbs. To determine whether herbs have greater macro- and micromineral concentrations than forage legumes and grasses, we conducted a 2-year experiment on a loamy-sand site in Denmark sown with a multi-species mixture comprised of three functional......, legumes and herbs. In general, herbs had greater concentrations of the macrominerals P, Mg, K and S and the microminerals Zn and B than grasses and legumes. Slurry application indirectly decreased Ca, S, Cu and B concentrations of total herbage because of an increase in the proportion of mineral...

  14. Suplementação energética para vacas leiteiras pastejando azevém com alta oferta de forragem Energy supplementation to dairy cows grazing Italian ryegrass with high-herbage allowance

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    Henrique Mendonça Nunes Ribeiro Filho

    2007-12-01

    Full Text Available Foi avaliado o efeito da quantidade de um suplemento energético (grão de milho sobre o consumo de forragem e a produção de leite em vacas leiteiras pastejando azevém (Lolium multiflorum. Os tratamentos foram 2 e 4 kg de grão de milho moído/vaca.dia. Oito vacas holandesas no terço médio de lactação foram divididas em dois grupos em um delineamento de dupla reversão. A oferta de MS foi 35 kg/vaca.dia no método rotativo. O consumo individual de forragem foi estimado por meio da produção fecal e da digestibilidade da forragem selecionada. As características da forragem oferecida e da pastagem após a saída dos animais não variaram entre piquetes. A digestibilidade da MO da forragem ingerida foi 76,1 ± 2,77%. O consumo de MO de forragem (13,5 ± 1,89 kg/dia, a produção de leite (22,5 ± 0,92 kg e os teores de gordura (32,4 ± 2,55 g/kg e proteína do leite (28,5 ± 0,82 g/kg não foram influenciados pelo nível de suplementação. Vacas leiteiras com potencial de produção de até 22,5 kg/dia, após o pico de produção, pastejando azevém anual manejado com alta oferta de forragem não respondem à suplementação com mais de 2,0 kg de grão de milho moído.The effect of a energy supplement (corn grain on the herbage intake and milk yield of lactating dairy cows grazing italian ryegrass (Lolium multiflorum was evaluated. The treatments were 2 and 4 kg of ground corn/cow.day. Eight Holstein cows in the second third of their lactation were divided in two groups in switch back procedure. The expected herbage allowance was 35 kg/cow.day in rotational grazing system. Individual herbage intake was estimated from output fecal and the digestibility of the selected herbage. The characteristics of the pre-grazing herbage and post-grazing characteristics did not change between paddocks. The herbage OM digestibility was 76.1 ± 2.77 %. The herbage OM intake (13.5 ± 1.89 kg/day, daily milk yield (22.5 ± 0.92 kg/day, milk fat content (32

  15. Method and system for estimating herbage uptake of an animal

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a method and a system for estimating the feeding value or the amount of consumed herbage of grazing animals. The estimated herbage uptake is based on measured and possibly estimated data which is supplied as input data to a mathematical model. Measured input data may...... by the model and possibly provided as output data. Measurements may be obtained by a sensor module carried by the animal and the measurements may be wirelessly transmitted from the sensor module to a receiver, possibly via relay transceivers....

  16. Diferentes massas de forragem sobre as variáveis morfogênicas e estruturais de azevém anual Different herbage masses on morphogenetic and structural traits of Italian ryegrass

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    Anna Carolina Cerato Confortin

    2013-03-01

    Full Text Available Características morfogênicas e estruturais de azevém (Lolium multiflorum Lam. foram avaliadas sob pastejo de borregas, em diferentes massas de forragem (MF: "Alta", "Média" e "Baixa", correspondentes a 1800-2000; 1400-1600 e 1000-1200kg ha-1 de matéria seca (MS, respectivamente. O delineamento experimental foi inteiramente casualizado, com três tratamentos e duas repetições de área. O método de pastejo foi de lotação contínua, com número variável de animais. Os dados foram submetidos a análises de correlação e regressão polinomial. A altura do pseudocolmo, o comprimento de lâminas intactas e desfolhadas e o número de folhas em senescência de azevém aumentaram linearmente com a elevação dos valores das massas de forragem. O número de folhas verdes ajustou-se ao modelo de regressão quadrático; o número de folhas em expansão e a densidade populacional de perfilhos não se ajustaram a nenhum modelo de regressão. Em pastagem de azevém, o manejo com massas de forragem dentro da faixa compreendida entre 1.100 e 1.800kg ha-1de MS não provoca alterações nas características morfogênicas dessa gramínea, mas causa diferenças nas características estruturais do dossel. Quando o azevém é manejado com 1.460kg ha-1de MS, seus perfilhos mantêm maior número de folhas verdes e com 1.800kg ha-1 de MS existe maior número de lâminas foliares em senescência e com maior comprimento.Morphogenetic and structural characteristics of Italian ryegrass (Lolium multiflorum Lam., utilized by female lambs and managed with different forage masses (FM were studied. The experimental design was completely randomized, with two area replications and three treatments, consisting of forage masses: "High", "Mean" and "Low", corresponding to 1,800-2,000; 1,400-1,600 and 1,000-1,200kg ha-1 of dry matter (DM, respectively. The grazing method was continuous with variable stocking rate. Data were subjected to correlation analysis and polynomial

  17. Comparison of methods for estimating herbage intake in grazing dairy cows

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Lund, Peter; Weisbjerg, Martin Riis

    2015-01-01

    season, and the herbage intake was estimated twice during each season. Cows were on pasture from 8:00 until 15:00, and were subsequently housed inside and fed a mixed ration (MR) based on maize silage ad libitum. Herbage intake was estimated with nine different methods: (1) animal performance (2) intake...

  18. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    OpenAIRE

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their dairy cows during summer. During grazing, the limited herbage intake is the main limitation of the dairy cows' production. This study examined opportunities for grass breeders to influence the quality of perennial ry...

  19. Caracterização da estrutura da vegetação numa pastagem natural do Bioma Pampa submetida a diferentes estratégias de manejo da oferta de forragem Structural characterization of a natural pasture vegetation from Pampa Biome under different herbage allowance management strategies

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    Fabio Pereira Neves

    2009-09-01

    Full Text Available Os objetivos neste trabalho foram descrever e investigar a dinâmica espaço-temporal de sítios alimentares em diferentes faixas de massa de forragem e altura do pasto, assim como o percentual de área efetivamente pastejada, a taxa de acúmulo de forragem e a produção de matéria seca de uma pastagem natural do Bioma Pampa. O delineamento utilizado foi o de blocos ao acaso com duas repetições, com três ofertas de forragem fixas (8, 12 e 16% e três ofertas de forragem variáveis ao longo do ano (8-12%, 12-8% e 16-12%, com o primeiro valor correspondendo à primavera. Na oferta fixa de forragem de 8%, observou-se maior percentual de área efetivamente pastejada, porém os valores médios de altura e massa de forragem foram inferiores aos das demais ofertas. As maiores ofertas de forragem, 16 e 16-12%, apresentaram altura média do pasto superior, 9,0 cm e massa de forragem de 2.000 kg/ha de matéria seca, porém, com área efetivamente pastejada inferior às observadas nas ofertas de 8 e 8-12%. Mesmo estratégias de manejo tão distintas, aproximadamente 60 a 70% dos sítios alimentares ocorreram em faixas consideradas limitantes ao potencial de ingestão de forragem por bovinos, com exceção dos tratamentos 16% e 16-12%, nos quais se observou menor frequência de sítios alimentares na faixa inferior a 6,0 cm de altura. Os sítios alimentares, em geral, se concentraram em faixas com altura The objective of this trial was to investigate the spatio-temporal dynamics of feeding sites stratified by strips of herbage mass and sward height, and the percentage of effectively grazed area, herbage growth rate and dry matter yield of a natural pasture from Pampa Biome managed with different herbage allowance management strategies. A randomized block design with two replications was used with three fixed herbage allowance (8, 12 and 16% and three herbage allowance variables throughout the year (8-12%, 12-8%, and 16-12%, with first value

  20. Variation and Correlations among European and North American Orchardgrass Germplasm for Herbage Yield and Nutritive Value

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    Joseph G. Robins

    2016-12-01

    Full Text Available Efforts to improve water-soluble carbohydrate (WSC concentrations are common in perennial forage grass breeding. Perennial ryegrass (Lolium perenne breeding has been very successful in developing new cultivars with high WSC and high agronomic performance. Breeding efforts are ongoing to improve the WSC of other perennial forage grasses, such as orchardgrass (Dactylis glomerata. The United States Department of Agriculture Forage and Range and Deutsche Saatveredelung orchardgrass breeding programs cooperated to characterize the expression and genotype by environment interaction (GEI of water-soluble carbohydrates in a collection of orchardgrass populations from both breeding programs. Additionally, the effort characterized the relationship between water-soluble carbohydrates and other agronomic and nutritive value traits in these populations. Overall, the Deutsche Saatveredelung populations had higher herbage mass (15%, rust resistance (59%, and later maturity. The Forage and Range Research populations had higher water-soluble carbohydrates (4%, nutritive value, and earlier maturity. However, results were highly dependent on GEI. Differences were very pronounced at the French and German field locations, but less pronounced at the two US locations. Combining the germplasm from the Forage and Range Research and Deutsche Saatveredelung programs may be a way to develop an improved base germplasm source that could then be used separately in the EU and US for water-soluble carbohydrate and other trait improvement.

  1. Defoliation patterns and tillering dynamics in Italian ryegrass under different herbage allowances

    Directory of Open Access Journals (Sweden)

    Larissa Arnhold Graminho

    2014-09-01

    Full Text Available This work was carried out in order to generate information on the tillering process and to contribute for the understanding of the defoliation process on Italian ryegrass (Lolium multiflorum Lam. grazed by lambs under different herbage allowances: 6, 8 and12 kg  of dry matter  per100 kg of animal live weight  per day. The grazing method was intermittent. The experimental design was completely randomized following a repeated measure arrangement, with three treatments and two area replications. The intensity of defoliation is greater at 6 and 9% herbage allowances. The defoliation interval is higher at 12% herbage allowance, intermediate at 9% and lower at 6%. The rates of tiller emergence, survival and death, stability index the tiller population are similar for the different herbage allowances and differ according to the phenological stage of ryegrass. Structural changes caused by canopy management with low herbage allowance and/or due to the advance in developmental stage of ryegrass alter defoliation strategies, with more intense and frequent grazing.

  2. The influence of feeding strategy on growth and rejection of herbage around dung pats and their decomposition

    NARCIS (Netherlands)

    Bosker, W.T.E.; Hoekstra, N.J.; Lantinga, E.A.

    2002-01-01

    Fresh cattle dung from four farms with different feeding strategies was used to create artificial dung pats in a continuously grazed pasture in order to compare the rejection of herbage growing around the pats, the effect on undisturbed herbage growth under cages and pat decomposition. The first far

  3. Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

    Directory of Open Access Journals (Sweden)

    Miguel Ruiz-Albarran

    2016-03-01

    Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

  4. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    NARCIS (Netherlands)

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their d

  5. Breeding for improved herbage and seed yield in Selaria sphacelata (Schumack) Staph and Hubbard ex Moss

    NARCIS (Netherlands)

    Wijk, van A.J.P.

    1980-01-01

    The simultaneous selection for yield of herbage and seed in Setaria sphacelata (Schumach.) Stapf and Hubbard ex Moss was studied, and the amount of variation present for each of these traits in relation to various plant characteristics was assessed in a spaced plant population and its open-pollinate

  6. The estimation of herbage yields under fire and grazing treatments in the Mountain Zebra National Park

    Directory of Open Access Journals (Sweden)

    J. De Klerk

    2001-07-01

    Full Text Available The application of fire as a management tool is often used to change the species composition of the vegetation and its cover to maintain plant communities in a specific successional stage. This study investigates the influence of two fire treatments (a head and a back fire on the plateau grassland communities in the Mountain Zebra National Park (MZNP. The production of herbage yield on grazed areas and areas protected from grazing which were subjected to two fire treatments, were compared with that of an unburnt control area subjected to grazing in the same homogenous grassland over two growing seasons. No differences were found in herbage production between the two fire treatment areas. After the burn the grazing exclosures achieved the same herbage yield as the control area within two growing seasons. In comparison, the grazed areas could after the burn only achieve a herbage yield equal to 55.7 of that of the control area. The results indicate that fire stimulates active vegetation growth on the plateau grasslands in MZNP leading to a higher production rate and better utilisation by game.

  7. Herbage Production and Quality of Shrub Indigofera Treated by Different Concentration of Foliar Fertilizer

    Directory of Open Access Journals (Sweden)

    L. Abdullah

    2010-12-01

    Full Text Available A field experiment on fodder legume Indigofera sp. was conducted to investigate the effects of foliar fertilizer concentration on forage yield and quality, and to identify optimum concentrations among the fertilizer treatments on herbage yield, chemical composition (CP, NDF, ADF, minerals, and in vitro dry matter (IVDMD as wll as organic matter (IVOMD digestibility in goat’s rumen. Randomized block design was used for the six concentration of fertilizer treatments; control, 10, 20, 30, 40, and 50 g/10 l with 3 replicates. Leaves were sprayed with foliar fertilizer at 30, 34, 38, and 42 days after harvest. Samples were collected at 2 harvest times with 60 days cutting interval. Application of the foliar fertilizer up to 30 g/10 l significantly increased herbage DM yield, twig numbers, tannin, saponin, Ca and P content, as well as herbage digestibility (IVDMD and IVOMD. The lower and higher concentration of foliar fertilizer resulted in lower value of those parameters, but NDF and ADF contents had the opposite patterns. The optimum level of foliar fertilizer that resulted the highest herbage yield and quality was 30 g/10 l, and the highest in vitro digestibility and Ca concentration was 20 g/10 l.

  8. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    NARCIS (Netherlands)

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their

  9. Chemical composition of lamina and sheath of Lolium perenne as affected by herbage management

    NARCIS (Netherlands)

    Hoekstra, N.J.; Struik, P.C.; Lantinga, E.A.; Schulte, R.P.O.

    2007-01-01

    The quality of grass in terms of form and relative amounts of energy and protein affects both animal production per unit of intake and nitrogen (N) utilization. Quality can be manipulated by herbage management and choice of cultivar. The effects of N application rate (0, 90 or 390 kg N ha¿1 year¿1),

  10. Plant morphology and herbage accumulation of signal grass with or without fertilization, under different light regimes

    Directory of Open Access Journals (Sweden)

    Clenardo Macedo Lopes

    Full Text Available ABSTRACT: The silvopastoral system has been suggested as an alternative to recover degraded pastures in tropical regions. However, trees reduce the light available for pastures, which may affect the growth and herbage accumulation. The objective of this study was to evaluate the morphogenesis, canopy structure and herbage accumulation of signalgrass ( Brachiaria decumbens subjected to three light regimes (0, 20 and 70% of natural shading and two fertilization levels (presence or absence of nitrogen, phosphorus and potassium. Leaf and stem elongation rates increased under shading but did not vary with fertilization. The leaf appearance rate was greater under fertilizer treatment but was generally similar among light regimes. The tiller density was greater in full sun and lower in intense shading. Tiller density responded to fertilization under full sun and moderate shading. Herbage accumulation increased by 42% with fertilization under full sun, 12% under moderate shading and did not vary under intense shading. Results showed that even under fertilization the herbage accumulation was limited by reduced light. However, under moderate shade the fertilization was important to raise tiller population over the growth cycles.

  11. Fatty acid, tocopherol and carotenoid content in herbage and milk affected by sward composition and season of grazing

    DEFF Research Database (Denmark)

    Larsen, Mette Krogh; Fretté, Xavier; Kristensen, Troels

    2012-01-01

    BACKGROUND: The aim of the present work was to study to what extent grazing large amounts ofwhite clover (WCL), red clover (RCL), lucerne (LUC) or chicory (CHI) was suitable for production of bovine milk with a high milk fat content of tocopherols, carotenoids, α-linolenic acid and conjugated......), carotenoids (6 μg g−1) and α-tocopherol (21 μg g−1 milk fat). There were minor differences between herbage types and periods, but multivariate analysis of these data showed no clear grouping. Chemical composition of herbage varied with species as well as period, but it was not possible to relatemilk and feed...... contents of specific fatty acids, carotenoids or tocopherols. CONCLUSION: All four herbages tested were suitable for production of milk with a high content of beneficial compounds. Thus any of these herbages could be used in production of such differentiated milk based on a large proportion of grazing...

  12. Herbage intake regulation and growth of rabbits raised on grasslands: back to basics and looking forward.

    Science.gov (United States)

    Martin, G; Duprat, A; Goby, J-P; Theau, J-P; Roinsard, A; Descombes, M; Legendre, H; Gidenne, T

    2016-10-01

    Organic agriculture is developing worldwide, and organic rabbit production has developed within this context. It entails raising rabbits in moving cages or paddocks, which enables them to graze grasslands. As organic farmers currently lack basic technical information, the objective of this article is to characterize herbage intake, feed intake and the growth rate of rabbits raised on grasslands in different environmental and management contexts (weather conditions, grassland type and complete feed supplementation). Three experiments were performed with moving cages at an experimental station. From weaning, rabbits grazed a natural grassland, a tall fescue grassland and a sainfoin grassland in experiments 1, 2 and 3, respectively. Rabbit diets were supplemented with a complete pelleted feed limited to 69 g dry matter (DM)/rabbit per day in experiment 1 and 52 g DM/rabbit per day in experiments 2 and 3. Herbage allowance and fiber, DM and protein contents, as well as rabbit intake and live weight, were measured weekly. Mean herbage DM intake per rabbit per day differed significantly (Prabbit metabolic weight (live weight0.75) and herbage protein and fiber contents. Across experiments, a 10 g DM increase in herbage allowance and a 100 g increase in rabbit metabolic weight corresponded to a mean increase of 6.8 and 9.6 g of herbage DM intake, respectively. When including complete feed, daily mean DM intakes differed significantly among experiments (Prabbit per day in experiment 2 to 163.6 g DM/rabbit per day in experiment 1. Metabolic weight of rabbits raised on grasslands increased linearly over time in all three experiments, yielding daily mean growth rates of 26.2, 19.2 and 28.5 g/day in experiments 1, 2 and 3, respectively. The highest growth rate was obtained on the sainfoin grassland despite lower concentrate supplementation. Thus, it seems possible to reduce complete feed supplementation without reducing animal performance. This possibility requires improving

  13. Measuring larval nematode contamination on cattle pastures: Comparing two herbage sampling methods.

    Science.gov (United States)

    Verschave, S H; Levecke, B; Duchateau, L; Vercruysse, J; Charlier, J

    2015-06-15

    Assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. Direct quantification of infective larvae (L3) on herbage is the most applied method to measure pasture larval contamination. However, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. The aim of this study was (1) to compare two different sampling methods in terms of pasture larval count results and time required to sample, (2) to assess the amount of variation in larval counts at the level of sample plot, pasture and season, respectively and (3) to calculate the required sample size to assess pasture larval contamination with a predefined precision using random plots across pasture. Eight young stock pastures of different commercial dairy herds were sampled in three consecutive seasons during the grazing season (spring, summer and autumn). On each pasture, herbage samples were collected through both a double-crossed W-transect with samples taken every 10 steps (method 1) and four random located plots of 0.16 m(2) with collection of all herbage within the plot (method 2). The average (± standard deviation (SD)) pasture larval contamination using sampling methods 1 and 2 was 325 (± 479) and 305 (± 444)L3/kg dry herbage (DH), respectively. Large discrepancies in pasture larval counts of the same pasture and season were often seen between methods, but no significant difference (P = 0.38) in larval counts between methods was found. Less time was required to collect samples with method 2. This difference in collection time between methods was most pronounced for pastures with a surface area larger than 1 ha. The variation in pasture larval counts from samples generated by random plot sampling was mainly due to the repeated measurements on the same pasture in the same season (residual variance

  14. Herbage Production and Quality of Shrub Indigofera Treated by Different Concentration of Foliar Fertilizer

    OpenAIRE

    Abdullah, L.

    2010-01-01

    A field experiment on fodder legume Indigofera sp. was conducted to investigate the effects of foliar fertilizer concentration on forage yield and quality, and to identify optimum concentrations among the fertilizer treatments on herbage yield, chemical composition (CP, NDF, ADF, minerals), and in vitro dry matter (IVDMD) as wll as organic matter (IVOMD) digestibility in goat’s rumen. Randomized block design was used for the six concentration of fertilizer treatments; control, 10, 20, 30, 40,...

  15. Effects of green manure herbage management and its digestate from biogas production on barley yield, N recovery, soil structure and earthworm populations

    DEFF Research Database (Denmark)

    Frøseth, Randi Berland; Bakken, Anne Kjersti; Bleken, Marina Azzaroli

    2014-01-01

    In repeatedly mown and mulched green manure leys, the mulched herbage contains substantial amounts of nitrogen (N), which may only slightly contribute to the following crops’ nutrient demand. The objective of the present work was to evaluate the effect of alternative strategies for green manure...... the same yields as whenall herbage was mulched the preceding season. Overall, the apparentNrecovery was enhanced from 7% when all herbage was mulched, to 16% when returned as digestate. A positive effect on earthworm density and biomass was seen after one season of retaining mulch material, rather than...... was reduced when N in herbage was not returned as mulch or digestate....

  16. Rumen degradation characteristics of ryegrass herbage and ryegrass silage are affected by interactions between stage of maturity and nitrogen fertilisation rate

    NARCIS (Netherlands)

    Heeren, J.A.H.; Podesta, S.C.; Hatew, B.; Klop, G.; Laar, van H.; Bannink, A.; Warner, D.; Jonge, de L.H.; Dijkstra, J.

    2014-01-01

    The objective of this experiment was to evaluate interaction effects between stage of maturity and N fertilization rate on rumen degradation characteristics determined with nylon bag incubations of ryegrass herbages and ryegrass silage. Grass herbage (n = 4) was cut after 3 or 5 weeks of regrowth an

  17. Matching plant and animal processes to alter nutrient supply in strip-grazed cattle: timing of herbage and fasting allocation.

    Science.gov (United States)

    Gregorini, P; Gunter, S A; Beck, P A

    2008-04-01

    This work aimed to assess the impact of timing of herbage allocation and fasting on patterns of ingestive behavior, herbage intake, ruminal fermentation, nutrient flow to the duodenum, and site and extent of digestion. Treatments were daily herbage allocation in the afternoon (1500 h, AHA), morning (0800 h, MHA), AHA after 20 h of fasting (AHAF), and MHA after 20 h of fasting (MHAF). Four ruminally and duodenally fistulated heifers (279 +/- 99 kg of BW) individually strip-grazed wheat pastures in a Latin-square design. Eating, rumination, and idling behavior were recorded every 2 min, and bite and eating step rates were measured hourly while the heifers were grazing (11 h MHA and AHA; 4 h MHAF and AHAF). Ruminal DM pools were measured 4 times daily (0800, 1200, 1500, and 1900 h) to estimate daily herbage DMI and its pattern. Ruminal fluid was sampled at these same times and also at 2300 h. Duodenal digesta was sampled over 2 d to determine the site of herbage digestibility. Treatments did not affect daily herbage DMI (16.5 g/ kg of BW, SE = 0.0025; P > 0.05). However, they altered the eating pattern; the evening grazing bout of AHA and AHAF was greater (P 0.05) among MHA, MHAF, and AHAF; however, it averaged 970, 40, 300, and 540 g/d, respectively, greater (P 0.05) for MHA, AHA, and AHAF, but was lower for MHAF (P 0.05) within fasted and nonfasted treatments; however, it was greater (P 0.05) among MHA, MHAF, and AHAF, but was greater (P nutrient supply. At the same amount of resource allocation, nutrient supply to grazing cattle can be modified through strategic grazing management.

  18. GROWTH AND HERBAGE YIELD OF SETARIA SPHACELATA GRASS IN RESPONSE TO VARYING CLIPPING STAGES

    OpenAIRE

    Mushtaque, M.

    2010-01-01

    Setaria sphacelata is an aggressive perennial grass of arid tropical habitats around the globe. It prefers very warmclimate and is restricted to these tropical environments. It was studied for its growth and herbage yield during earlysummer in 2003. Grass nursery of this plant was raised through its stubbles on a site having sandy loam to loam soil witha pH of 7.85 in plot size 1m x 3m. The experiment was carried out in complete randomized design with four replications.Four clipping stages i....

  19. Herbage intake and ruminal digestion of dairy cows grazed on perennial ryegrass pasture either in the morning or evening.

    Science.gov (United States)

    Ueda, Koichiro; Mitani, Tomohiro; Kondo, Seiji

    2016-08-01

    This study aimed to clarify diurnal fluctuations of herbage intake, ruminal fermentation of herbage carbohydrates and proteins, and digesta particulate weight in the rumen of grazing dairy cows. Six ruminally cannulated, non-lactating dairy cows were grazed on perennial ryegrass/white clover pasture either in the morning (04.00 to 08.00 hours) or the evening (16.00 to 20.00 hours). Cows grazed in the evening spent more time (P dairy cows compared with morning grazing, in terms of ruminal fermentable energy intake and nitrogen utilization efficiency.

  20. Effect of incremental flaxseed supplementation of an herbage diet on methane output and ruminal fermentation in continuous culture

    Science.gov (United States)

    A 4-unit dual-flow continuous culture fermentor system was used to assess the effect of increasing flax supplementation of an herbage-based diet on nutrient digestibility, bacterial N synthesis and methane output. Treatments were randomly assigned to fermentors in a 4 x 4 Latin square design with 7 ...

  1. Fluorine in herbage and water supplies in Northern Ireland in relation to the possible occurrence of fluorosis in livestock

    Energy Technology Data Exchange (ETDEWEB)

    Jordon, J.W.; Alston, A.M.

    1966-01-01

    The mean fluorine content of herbage in areas free from industrial contamination was 3 ppM (range: 1 to 10 ppM). High fluorine contents caused by contamination were found in the vicinity of brickworks and related industries near Dungannon and Coal-island. The mean fluorine content of herbage within half a mile of the works was 30 ppM (range: 11 to 71 ppM). Similar fluorine concentrations occurred in herbage close to a fertilizer factory near Londonderry, but no appreciable contamination was found in any other area. Industrial emissions had no apparent effect on the fluorine content of water supplies. Most water supplies contained less than 0.3 ppM fluorine, except in South Fermanagh where up to 5.7 ppM occurred in water from deep wells. Ingestion by cattle of contaminated herbage or water with a high fluorine content was reflected by a high excretion of fluorine in the urine. Concentrations of up to 17 ppM were recorded. Mild symptoms of dental fluorosis were detected in a few cows, but levels of fluorine ingestion were not sufficient to cause loss of production or affect the health of the animals.

  2. Case Study: A snapshot of fatty acids composition of grass herbage as affected by time of day

    Science.gov (United States)

    Manipulation of functional poly unsaturated fatty acid (PUFA) in ruminant products depends on rumen biohydrogenation and the net amount and composition of fatty acid ingested. Total non-structural carbohydrates and DM concentrations of herbage increase during the day; however, it is not known if fat...

  3. Effect of time of maize silage supplementation on herbage intake, milk production, and nitrogen excretion of grazing dairy cows.

    Science.gov (United States)

    Al-Marashdeh, O; Gregorini, P; Edwards, G R

    2016-09-01

    The objective of this study was to evaluate the effect of feeding maize silage at different times before a short grazing bout on dry matter (DM) intake, milk production, and N excretion of dairy cows. Thirty-six Friesian × Jersey crossbred lactating dairy cows were blocked in 9groups of 4 cows by milk solids (sum of protein and fat) production (1.26±0.25kg/d), body weight (466±65kg), body condition score (4±0.48), and days in milk (197±15). Groups were then randomly assigned to 1 of 3 replicates of 3 treatments: control; herbage only, supplemented with 3kg of DM/cow of maize silage after morning milking approximately 9h before pasture allocation (9BH); and supplemented with 3kg of DM/cow of maize silage before afternoon milking approximately 2h before pasture allocation (2BH). Herbage allowance (above the ground level) was 22kg of DM/cow per day for all groups of cows. Cows were allocated to pasture from 1530 to 2030 h. Maize silage DM intake did not differ between treatments, averaging 3kg of DM/cow per day. Herbage DM intake was greater for control than 2BH and 9BH, and greater for 9BH than 2BH (11.1, 10.1, and 10.9kg of DM/cow per day for control, 2BH, and 9BH, respectively). The substitution rate (kilograms of herbage DM per kilograms of maize silage DM) was greater for 2BH (0.47) than 9BH (0.19). Milk solids production was similar between treatments (overall mean 1.2kg/cow per day). Body weight loss tended to be less for supplemented than control cows (-0.95, -0.44, and -0.58kg/cow per day for control, 2BH, and 9BH, respectively). Nitrogen concentration in urine was not affected by supplementation or time of supplementation, but estimated urinary N excretion tended to be greater for control than supplemented cows when urinary N excretion estimated using plasma or milk urea N. At the time of herbage meal, nonesterified fatty acid concentration was greater for control than supplemented cows and greater for 9BH than 2BH (0.58, 0.14, and 0.26mmol/L for

  4. Modelling above-ground herbage mass for a wide range of grassland community types

    NARCIS (Netherlands)

    Duru, M.; Adam, M.Y.O.; Cruz, P.; Martin, G.; Ansquer, P.; Ducourtieux, C.; Jouany, C.; Theau, J.P.; Viegas, J.

    2009-01-01

    Whereas it is recognized that management of plant diversity can be the key to reconciling production and environmental aims, most grassland models are tailored for high-value grass species. We proposed to adapt a mono-specific grass model to take into account specific features of species-rich perman

  5. Composição morfológica da forragem consumida por bovinos de corte durante o rebaixamento do capim-marandu submetido a estratégias de pastejo rotativo Morphological composition of the herbage consumed by beef cattle during the grazing down process of marandu palisadegrass subjected to rotational strategies

    Directory of Open Access Journals (Sweden)

    Júlio Kuhn da Trindade

    2007-06-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de estratégias de pastejo rotativo sobre a composição morfológica da forragem consumida por bovinos de corte em pastos de Brachiaria brizantha cv. Marandu. Os pastejos foram realizados sempre que o dossel atingia 95 ou 100% de intercepção luminosa (IL até as alturas pós-pastejo de 10 e 15 cm. Foi avaliada a composição morfológica das extrusas coletadas de animais fistulados no esôfago em três etapas ao longo do rebaixamento dos pastos. À medida que o rebaixamento progrediu, a proporção de lâminas foliares na extrusa diminuiu e a de colmos e de material morto aumentou. Pastejos iniciados com 100% de IL ou realizados até a altura pós-pastejo de 10 cm resultaram em menor proporção de lâminas foliares e maior de colmos e de material morto. O tratamento 95/15 foi consistente entre os tratamentos que apresentaram as maiores proporções de lâminas foliares e menores de colmos e de material e, mesmo no final do rebaixamento, apresentou, ainda, mais de 50% de proporção de lâminas foliares na extrusa. Os resultados obtidos indicam que, durante o rebaixamento do dossel, pastejos mais freqüentes e menos severos proporcionam aos animais a obtenção de dietas com elevada proporção de lâminas foliares, o que deve aumentar o valor nutritivo da forragem consumida.The objective of this work was to evaluate the effect of rotational grazing strategies on the morphological composition of the herbage consumed by beef cattle in Brachiaria brizantha cv. Marandu swards. Grazings were carried out when swards achieved 95 and 100% of light interception (LI until postgrazing heights of 10 and 15 cm. Morphological composition of the herbage consumed was determined from extrusa samples harvested from oesophageal-fistulated animals in three occasions, during the grazing down process. As sward height decreased from the pre-grazing condition, the proportion of leaf laminae in the extrusa decreased

  6. Effects of herbage intake on goat performance in the mediterranean type natural pastures.

    Science.gov (United States)

    Hakyemez, Basri H; Gokkus, Ahmet; Savas, Turker; Yurtman, Ismail Y

    2009-02-01

    This study aimed at identifying changes in natural pastures during the grazing season and investigating the effects of these changes on pasture feeding potential for high yielding dairy goats. During the study, 12 dairy goats were grazed on a 1.5 ha natural pasture for three months from April to June in 2003, 2004 and 2005. The goats were fed 0.5 kg/day of concentrate as a supplement during the grazing season. Botanical composition, herbage production and intake, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the pasture were determined. Live weight, milk yield, milk dry matter (DM) and fat content of the goats were monitored. The data were analyzed using a linear model, which evaluated the effects of grazing seasons in each year. Based on the three-year average, 87% of pasture was herbaceous plants and the remaining was shrubs in DM basis with Cistus creticus, Quercus ithaburensis, Pistacia atlantica and Asparagus acutifolius being the major shrub species. The herbage yield in June was significantly lower than in other months in all years (P = 0.001). In all experimental years, the CP content of the pasture decreased but the structural carbohydrates increased as the grazing season proceeded. While live weight was not affected by grazing periods except for 2004 (P = 0.001), milk yield significantly decreased with advancing grazing period (P = 0.001). The results of the present study indicate that natural pasture has a supportive effect in April and May on the milk yield of lactating goats which are in mid-lactation, and suggested that supplementary feeding is required in consecutive grazing periods.

  7. Effect of supplementing orchardgrass herbage with a total mixed ration or flaxseed on fermentation profile and bacterial protein synthesis in continuous culture.

    Science.gov (United States)

    Soder, K J; Brito, A F; Rubano, M D

    2013-05-01

    A 4-unit dual-flow continuous culture fermentor system was used to evaluate the effects of supplementing fresh herbage with a total mixed ration (TMR) or flaxseed on nutrient digestibility, fermentation profile, and bacterial N synthesis. Diets were randomly assigned to fermentors in a 4 × 4 Latin square design. Each fermentor was fed a total of 70 g of dry matter/d of 1 of 4 diets: (1) 100% freeze-dried orchardgrass herbage (Dactylis glomerata L.; HERB), (2) 100% freeze-dried TMR (100TMR), (3) 50% orchardgrass herbage supplemented with 50% TMR (50TMR), or (4) 90% orchardgrass herbage supplemented with 10% ground flaxseed (Linum usitatissimum L.; FLAX). Preplanned, single degree of freedom orthogonal contrasts were constructed to assess the effects of feeding system (HERB vs. 100TMR), herbage supplementation (HERB vs. 50TMR + FLAX), and herbage supplemental source (50TMR vs. FLAX). Compared with the HERB diet, the 100TMR diet significantly reduced apparent digestibility of neutral detergent fiber. Herbage supplementation with 50TMR or FLAX significantly reduced or tended to reduce apparent digestibilities of dry matter, organic matter, and neutral detergent fiber, suggesting that replacing high-quality, highly digestible fresh herbage with forage TMR likely caused depressions in nutrient digestibilities. Concentration of total volatile fatty acids, molar proportions of acetate, propionate, and isovalerate, as well as the acetate:propionate ratios were all significantly higher in fermentors fed 100TMR compared with HERB, likely in response to enhanced supply of fermentable energy. In general, feeding system, herbage supplementation, and type of supplementation did not affect N metabolism in the present study. The few significant changes in N metabolism (e.g., flows of total N and non-NH3-N) were primarily linked to increased fermentor N supply with feeding herbage-based diets (HERB and FLAX). Although TMR-based diets decreased nutrient digestibility slightly, TMR

  8. PCDD/F and metal concentrations in soil and herbage samples collected in the vicinity of a cement plant.

    Science.gov (United States)

    Schuhmacher, M; Bocio, A; Agramunt, M C; Domingo, J L; de Kok, H A M

    2002-07-01

    In May 2000, the levels of a number of metals (As, Cd, Pb, Hg, Zn, Co, Cu, Mn, Sn, Tl, Cr, Ni and V) were determined in 16 soil and herbage samples collected in the vicinity of a cement plant from Sta. Margarida i els Monjos (Catalonia, Spain). Metal concentrations were also analyzed in air filters from three sampling stations placed nearthe facility. For most metals, concentrations were similar or even lower than previously reported values for other areas from Catalonia. On the other hand, the levels of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) were also determined in four soil and 16 herbage samples. Mean values were 0.37 and 0.16 ng I-TEQ/kg for soils and herbage, respectively, values which in comparison with data from other surveys are rather low. No significant differences between metal and PCDD/F concentrations in samples collected at distances lower or greater than 3.5 km of the facility were noted. The current results show that the cement plant has a low impact on the metal and PCDD/F levels in the environment under direct influence of the facility. These results should be of interest to assess future temporal variations in the levels of metals and PCDD/Fs in this area.

  9. Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass v. dwarf elephant grass and peanut pastures.

    Science.gov (United States)

    Andrade, E A; Almeida, E X; Raupp, G T; Miguel, M F; de Liz, D M; Carvalho, P C F; Bayer, C; Ribeiro-Filho, H M N

    2016-10-01

    Management strategies for increasing ruminant legume consumption and mitigating methane emissions from tropical livestock production systems require further study. The aim of this work was to evaluate the herbage intake, animal performance and enteric methane emissions of cattle grazing dwarf elephant grass (DEG) (Pennisetum purpureum cv. BRS Kurumi) alone or DEG with peanut (Arachis pintoi cv. Amarillo). The experimental treatments were the following: DEG pastures receiving nitrogen fertilization (150 kg N/ha as ammonium nitrate) and DEG intercropped with peanut plus an adjacent area of peanut that was accessible to grazing animals for 5 h/day (from 0700 to 1200 h). The animals grazing legume pastures showed greater average daily gain and herbage intake, and shorter morning and total grazing times. Daily methane emissions were greater from the animals grazing legume pastures, whereas methane emissions per unit of herbage intake did not differ between treatments. Allowing animals access to an exclusive area of legumes in a tropical grass-pasture-based system can improve animal performance without increasing methane production per kg of dry matter intake.

  10. Gradual Accumulation of Heavy Metals in an Industrial Wheat Crop from Uranium Mine Soil and the Potential Use of the Herbage

    Directory of Open Access Journals (Sweden)

    Gerhard Gramss

    2016-10-01

    Full Text Available Testing the quality of heavy-metal (HM excluder plants from non-remediable metalliferous soils could help to meet the growing demands for food, forage, and industrial crops. Field cultures of the winter wheat cv. JB Asano were therefore established on re-cultivated uranium mine soil (A and the adjacent non-contaminated soil (C. Twenty elements were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS from soils and plant sections of post-winter seedlings, anthesis-state, and mature plants to record within-plant levels of essential and toxic minerals during ripening and to estimate the (reuse of the soil-A herbage in husbandry and in HM-sensitive fermentations. Non-permissible HM loads (mg∙kg−1∙DW of soil A in Cd, Cu, and Zn of 40.4, 261, and 2890, respectively, initiated the corresponding phytotoxic concentrations in roots and of Zn in shoots from the seedling state to maturity as well as of Cd in the foliage of seedlings. At anthesis, shoot concentrations in Ca, Cd, Fe, Mg, Mn, and Zn and in As, Cr, Pb, and U had fallen to a mean of 20% to increase to 46% during maturation. The respective shoot concentrations in C-grown plants diminished from anthesis (50% to maturity (27%. They were drastically up/down-regulated at the rachis-grain interface to compose the genetically determined metallome of the grain during mineral relocations from adjacent sink tissues. Soil A caused yield losses of straw and grain down to 47.7% and 39.5%, respectively. Nevertheless, pronounced HM excluder properties made Cd concentrations of 1.6–3.08 in straw and 1.2 in grains the only factors that violated hygiene guidelines of forage (1. It is estimated that grains and the less-contaminated green herbage from soil A may serve as forage supplement. Applying soil A grains up to 3 and 12 in Cd and Cu, respectively, and the mature straw as bioenergy feedstock could impair the efficacy of ethanol fermentation by Saccharomyces cerevisiae.

  11. Effects of rainwater harvesting on herbage diversity and productivity in degraded Aravalli hills in western India

    Institute of Scientific and Technical Information of China (English)

    G. Singh; G.R. Choadhary; B.Ram; N.K. Limba

    2011-01-01

    Over-exploitation and rural growth have severely damagednative vegetations of Aravalli hills in Rajasthan, India. This study wasconducted to evaluate the effects of different restoration practices (I.e.,rainwater harvesting (RWH) and planting of tree seedlings) on improve-ment in soil water and nutrients and growth and biomass of herbaceousvegetation. Contour trench (CT), Gradonie (G), Box trench (BT), V-ditch(VD) and a control were imposed on 75 plots (each of 700 m) in naturalslope gradient defined as 20% slopes in 2005.Each plot had three micro-sites of 1-m at up (USP), middle (MSP) andlower (LSP) part of the plot for observation in 2008. The existed gradient(due to soil texture and topographic features) of soil Ph, EC, SOC, NH-N, NO-N and PO-P in June 2005 between >20% to 20% slopes, comparedwith -P. Further, CT treatment was found to be the best treat-ment in minimizing biomass variance in different slopes. Conclusively,soil texture and topographic features controlled soil water and nutrientsavailability. Rainwater harvesting techniques increased soil water storageand nutrient retention and also enhanced vegetation status and biomassby minimizing the effects of hillslopes. Thus depending upon the siteconditions, suitable RWH technique could be adopted to increase herb-age biomass while rehabilitating the degraded hills.

  12. Simulation of herbage yield and growth components of Cock’s foot (Dactylis glomerata L. in Jablje using the calibrated LINGRA-N model

    Directory of Open Access Journals (Sweden)

    Tjaša POGAČAR

    2015-11-01

    Full Text Available In the study the previously calibrated LINGRA-N model was used for a long term simulation (1964–2013 of the herbage  dry matter yield (GRASS and growth analysis of Cock’s foot (Dactylis glomerata L. in Jablje. Changes in the yearly  GRASS variability are reflected in the appearance of outliers in  the second half of the study period. The biggest reductions in GRASS are seen in the years 1992, 1993 and 2003. These are  the driest years according to meteorological variables (high  maximum and minimum air temp eratures, low precipitation  and also according to the simulations, with the lowest  reduction factor for crop growth due to drought. The potential  yield (YIELD is not linearly dependent on meteorological  variables. Some growth compone nts were compared on a daily  basis in a dry year (1993 and an average year (1994. In 1993, for instance, 53 % of photosynth etically active radiation was  intercepted, against 75 % in  1994. Seasonal development of  the actual soil moisture content was linked to the development  of the leaf area index and consequently to the mass of green  leaves, to the roots mass, to the mass of dead leaves and to  GRASS. The results highlight the need for further research, on  field and with simulations. As re gards the latter, we have to  keep in mind that they inevitably involve various  uncertainties.   

  13. [Carbon Source Utilization Characteristics of Soil Microbial Community for Apple Orchard with Interplanting Herbage].

    Science.gov (United States)

    Du, Yi-fei; Fang, Kai-kai; Wang, Zhi-kang; Li, Hui-ke; Mao, Peng-juan; Zhang, Xiang-xu; Wang, Jing

    2015-11-01

    As soil fertility in apple orchard with clean tillage is declined continuously, interplanting herbage in orchard, which is a new orchard management model, plays an important role in improving orchard soil conditions. By using biolog micro-plate technique, this paper studied the functional diversity of soil microbial community under four species of management model in apple orchards, including clear tillage model, interplanting white clover model, interplanting small crown flower model and interplanting cocksfoot model, and the carbon source utilization characteristics of microbial community were explored, which could provide a reference for revealing driving mechanism of ecological process of orchard soil. The results showed that the functional diversity of microbial community had a significant difference among different treatments and in the order of white clover > small crown flower > cocksfoot > clear tillage. The correlation analysis showed that the average well color development (AWCD), Shannon index, Richness index and McIntosh index were all highly significantly positively correlated with soil organic carbon, total nitrogen, microbial biomass carbon, and Shannon index was significantly positively correlated with soil pH. The principal component analysis and the fingerprints of the physiological carbon metabolism of the microbial community demonstrated that grass treatments improved carbon source metabolic ability of soil microbial community, and the soil microbes with perennial legumes (White Clover and small crown flower) had a significantly higher utilization rate in carbohydrates (N-Acetyl-D-Glucosamine, D-Mannitol, β-Methyl-D-Glucoside), amino acids (Glycyl-L-Glutamic acid, L-Serine, L-Threonine) and polymers (Tween 40, Glycogen) than the soil microbes with clear tillage. It was considered that different treatments had the unique microbial community structure and peculiar carbon source utilization characteristics.

  14. Seed Production, Herbage Residue and Crude Protein Content of Centro (Centrosema pubescens in the Year of Establishment at Shika, Nigeria

    Directory of Open Access Journals (Sweden)

    Omokanye, AT.

    2001-01-01

    Full Text Available A field trial was carried out on seed production pattern of centro (Centrosema pubescens, in the year of establishment in a sub humid environment of Nigeria as influenced by sowing date and phosphorus application levels. The herbage residue and its crude protein content were also determined after pod harvest. The variation in seeds per pod for plantings between June 21 to August 2 was from 16.5 to 14.5, while for unfertilized and fertilized plots seeds number varied between 12.6 and 16.2/pod. The weight of 1000 seeds decreased with delayed planting. Phosphorus application improved seed weight. Seed yield was highest (1000 kg/ha for July 5 sowing with phosphorus application of 60 kg/ha P205 combination. The variation in mean seed yield for planting between June 21 and August 2 was 782.0 to 360.3 kg/ha. The application of 0 to 60 kg/ha P205 resulted in mean seed yields of 405.7 to 776.8 kg/ha. Herbage residue was favoured more by June 21 sowing and the application of 60 kg/ha P205. The crude protein content was better with August sowing and 60 kg/ha P205.

  15. Effect of four plant species on soil 15N-access and herbage yield in temporary agricultural grasslands

    DEFF Research Database (Denmark)

    Pirhofter-Walzl, Karin; Eriksen, Jørgen; Rasmussen, Jim

    2013-01-01

    access to greater amounts of soil 15N compared with a shallow-rooting binary mixture, and if leguminous plants affect herbage yield and soil 15N-access. Methods 15N-enriched ammonium-sulphate was placed at three different soil depths (0.4, 0.8 and 1.2 m) to determine the depth dependent soil 15N...... has greater herbage yields than a shallow-rooting two-species mixture and pure stands, if deep-rooting grassland species are superior in accessing soil 15N from 1.2 m soil depth compared with shallow-rooting plant species and vice versa, if a mixture of deep- and shallow-rooting plant species has....... This positive plant diversity effect could not be explained by complementary soil 15N-access of the different plant species from 0.4, 0.8 and 1.2 m soil depths, even though deep-rooting chicory acquired relatively large amounts of deep soil 15N and shallow-rooting perennial ryegrass when grown in a mixture...

  16. Effect of nitrogen fertilization rate and regrowth interval of grass herbage on methane emission of zero-grazing lactating dairy cows

    NARCIS (Netherlands)

    Warner, D.; Podesta, S.C.; Hatew, B.; Klop, G.; Laar, van H.; Bannink, A.; Dijkstra, J.

    2015-01-01

    Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (pr

  17. Effects of species diversity on seasonal variation in herbage yield and nutritive value of seven binary grass-legume mixtures and pure grass under cutting

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2016-01-01

    , Lotus corniculatus) and white clover (WC, Trifolium repens); WC was also sown with hybrid ryegrass (HR, Lolium × boucheanum), meadow fescue (MF, Festuca pratensis) and timothy (TI, Phleum pratense). Herbage productivity was lowest in pure PR followed by PR/BT, and highest in PR/RC; this mixture had...

  18. The ability of the nematode-trapping fungus Duddingtonia flagrans to reduce the transmission of infective Ostertagia ostertagi larvae from faeces to herbage

    DEFF Research Database (Denmark)

    Fernandez, A.S.; Larsen, M.; Nansen, P.

    1999-01-01

    The ability of two isolates of the nematode-trapping fungus Duddingtonia flagrans to reduce the numbers of gastrointestinal nematode larvae on herbage was tested in three plot studies. Artificially prepared cow pats containing Ostertagia ostertagi eggs, with and without fungal spores, were...

  19. Annual variation in the levels of metals and PCDD/PCDFs in soil and herbage samples collected near a cement plant.

    Science.gov (United States)

    Schuhmacher, M; Agramunt, M C; Bocio, A; Domingo, J L; de Kok, H A M

    2003-07-01

    In May 2000, the levels of a number of metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sn, Tl, V and Zn) and polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in soil and herbage samples collected near a cement plant from Sta. Margarida i els Monjos (Catalonia, Spain). To determine the temporal variation in the concentrations of metals and PCDD/PCDFs, in May 2001 soil and herbage samples were again collected at the same sampling points and analyzed for the levels of metals and PCDD/PCDFs. In general terms, metal concentrations in soils did not change between May 2000 and May 2001, while significant decreases in the levels of Cr, Ni and V were found in herbage. On the other hand, no significant differences in the mean I-TEQ values of PCDD/PCDFs were found in soil and herbage samples. The results of this survey show that according to the annual variation in the levels of metals and PCDD/PCDFs the environmental impact of the cement plant on the area under its direct influence is not relevant.

  20. Modelling the concentrations of nitrogen and water-soluble carbohydrates in grass herbage ingested by cattle under strip-grazing management

    NARCIS (Netherlands)

    Hoekstra, N.J.; Schulte, R.P.O.

    2008-01-01

    There is scope of increasing the nitrogen (N) efficiency of grazing cattle through manipulation of the energy and N concentrations in the herbage ingested. Because of asymmetric grazing by cattle between individual plant parts, it has not yet been established how this translates into the

  1. e-Cow: an animal model that predicts herbage intake, milk yield and live weight change in dairy cows grazing temperate pastures, with and without supplementary feeding.

    Science.gov (United States)

    Baudracco, J; Lopez-Villalobos, N; Holmes, C W; Comeron, E A; Macdonald, K A; Barry, T N; Friggens, N C

    2012-06-01

    This animal simulation model, named e-Cow, represents a single dairy cow at grazing. The model integrates algorithms from three previously published models: a model that predicts herbage dry matter (DM) intake by grazing dairy cows, a mammary gland model that predicts potential milk yield and a body lipid model that predicts genetically driven live weight (LW) and body condition score (BCS). Both nutritional and genetic drives are accounted for in the prediction of energy intake and its partitioning. The main inputs are herbage allowance (HA; kg DM offered/cow per day), metabolisable energy and NDF concentrations in herbage and supplements, supplements offered (kg DM/cow per day), type of pasture (ryegrass or lucerne), days in milk, days pregnant, lactation number, BCS and LW at calving, breed or strain of cow and genetic merit, that is, potential yields of milk, fat and protein. Separate equations are used to predict herbage intake, depending on the cutting heights at which HA is expressed. The e-Cow model is written in Visual Basic programming language within Microsoft Excel®. The model predicts whole-lactation performance of dairy cows on a daily basis, and the main outputs are the daily and annual DM intake, milk yield and changes in BCS and LW. In the e-Cow model, neither herbage DM intake nor milk yield or LW change are needed as inputs; instead, they are predicted by the e-Cow model. The e-Cow model was validated against experimental data for Holstein-Friesian cows with both North American (NA) and New Zealand (NZ) genetics grazing ryegrass-based pastures, with or without supplementary feeding and for three complete lactations, divided into weekly periods. The model was able to predict animal performance with satisfactory accuracy, with concordance correlation coefficients of 0.81, 0.76 and 0.62 for herbage DM intake, milk yield and LW change, respectively. Simulations performed with the model showed that it is sensitive to genotype by feeding environment

  2. How does the suppression of energy supplementation affect herbage intake, performance and parasitism in lactating saddle mares?

    Science.gov (United States)

    Collas, C; Fleurance, G; Cabaret, J; Martin-Rosset, W; Wimel, L; Cortet, J; Dumont, B

    2014-08-01

    Agroecology opens up new perspectives for the design of sustainable farming systems by using the stimulation of natural processes to reduce the inputs needed for production. In horse farming systems, the challenge is to maximize the proportion of forages in the diet, and to develop alternatives to synthetic chemical drugs for controlling gastrointestinal nematodes. Lactating saddle mares, with high nutritional requirements, are commonly supplemented with concentrates at pasture, although the influence of energy supplementation on voluntary intake, performance and immune response against parasites has not yet been quantified. In a 4-month study, 16 lactating mares experimentally infected with cyathostome larvae either received a daily supplement of barley (60% of energy requirements for lactation) or were non-supplemented. The mares were rotationally grazed on permanent pastures over three vegetation cycles. All the mares met their energy requirements and maintained their body condition score higher than 3. In both treatments, they produced foals with a satisfying growth rate (cycle 1: 1293 g/day; cycle 2: 1029 g/day; cycle 3: 559 g/day) and conformation (according to measurements of height at withers and cannon bone width at 11 months). Parasite egg excretion by mares increased in both groups during the grazing season (from 150 to 2011 epg), independently of whether they were supplemented or not. This suggests that energy supplementation did not improve mare ability to regulate parasite burden. Under unlimited herbage conditions, grass dry matter intake by supplemented mares remained stable around 22.6 g DM/kg LW per day (i.e. 13.5 kg DM/al per day), whereas non-supplemented mares increased voluntary intake from 22.6 to 28.0 g DM/kg LW per day (13.5 to 17.2 kg DM/al per day) between mid-June and the end of August. Hence total digestible dry matter intake and net energy intake did not significantly differ between supplemented and non-supplemented mares during the

  3. Herbage Production, Nutritive Value and Grazing Preference of Diploid and Tetraploid Perennial Ryegrass Cultivars (Lolium perenne L. Producción de Fitomasa, Calidad Nutritiva y Preferencia de Pastoreo de Cultivares Diploides y Tetraploides de Ballica Perenne (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Oscar A Balocchi

    2009-09-01

    Full Text Available The objective of this study was to determine, under the soil and climatic conditions of Southern Chile, the effect of the ploidy of perennial ryegrass (Lolium perenne L. cultivars on herbage production, nutritive value, grazing preference and utilization of pasture produced. This study was conducted in southern Chile, Valdivia Province, and was evaluated for 3 years. The tetraploid cultivars used were Quartet (4n, Gwendal (4n, Pastoral (4n and Napoleon (4n. The diploid cultivars were Anita (2n, Jumbo (2n, Aries (2n, and Yatsyn 1 (2n.When the average sward height reached 20 cm, all plots were simultaneously grazed by dairy cows for a period of 24 h. Before and after grazing, sward height, dry matter availability and nutritive value were evaluated. Grazing preference was visually assessed every 5 min for a period of 2.5 h after the afternoon milking. During the 3-year period 20 grazing events were evaluated. A randomized complete block design, with eight cultivars and three replicates, was used. Diploid cultivars showed greater herbage mass accumulation than tetraploid cultivars (P ≤ 0.05. No significant differences were obtained in the annual average crude protein content. Nevertheless, tetraploid cultivars showed a greater D value than diploid cultivars, except during the third year when the difference was not statistically significant. Dairy cows grazed more time on tetraploid cultivars. Considering, additionally, the residual herbage mass after grazing and the percentage of pasture utilization, diploid cultivars were less intensively grazed, suggesting a lower consumption by the cows.El objetivo de este estudio fue determinar, bajo las condiciones edafoclimáticas del sur de Chile, el efecto de la ploidía de cultivares de ballica perenne (Lolium perenne L. sobre el rendimiento de fitomasa, calidad nutricional, preferencia de pastoreo y porcentaje de utilización del forraje producido. El ensayo se realizó en el sur de Chile, provincia de

  4. Forage mass and the nutritive value of pastures mixed with forage peanut and red clover

    Directory of Open Access Journals (Sweden)

    Ricardo Lima de Azevedo Junior

    2012-04-01

    Full Text Available The objective of this research was to estimate three pasture-based systems mixed with elephantgrass + spontaneous growth species, annual ryegrass, for pasture-based system 1; elephantgrass + spontaneous growth species + forage peanut, for pasture-based system 2; and elephantgrass + spontaneous growth species + annual ryegrass + red clover, for pasture-based system 3. Elephantgrass was planted in rows 4 m apart from each other. During the cool-season, annual ryegrass was sown in the alleys between the rows of elephantgrass; forage peanut and red clover were sown in the alleys between the elephantgrass according to the respective treatment. The experimental design was totally randomized in the three treatments (pasture-based systems, two replicates (paddocks in completely split-plot time (grazing cycles. Holstein cows receiving 5.5 kg-daily complementary concentrate feed were used in the evaluation. Pre-grazing forage mass, botanical composition and stocking rate were evaluated. Samples of simulated grazing were collected to analyze organic matter (OM, neutral detergent fiber (NDF, crude protein (CP and organic matter in situ digestibility (OMISD. Nine grazing cycles were performed during the experimental period (341 days. The average dry matter values for pre-grazing and stocking rate were 3.34; 3.46; 3.79 t/ha, and 3.28; 3.34; 3.60 AU/ha for each respective pasture-based system. Similar results were observed between the pasture-based systems for OM, NDF, CP and OMISD. Considering forage mass, stocking rate and nutritive value, the pasture-based system intercropped with forage legumes presented better performance.

  5. [Prognosis of accumulation of 137Cs and 90Sr in the herbage of the main types of the Belarus Polessje meadows using agrochemical soil properties].

    Science.gov (United States)

    Podoliak, A G; Timofeev, S F; Grebenshchikova, N V; Arastovich, T V; Zhdanovich, V P

    2005-01-01

    On the basis of long-term stationary experience it was established that the minimum accumulation quantities for 137Cs and 90Sr in the herbage of the dry, lowland and flood-plain types of the Belarus Polessje meadows contaminated with Chemobyl radionuclides are determined when the optimum of basic agrochemical soil properties is achieved with application of the scientifically reasonable protective measures. For remote prognosis of radionuclide contents in natural and cultural meadow herbage the use of transfer factors (TFa, (Bq/kg)(kBq/m2)) based on the complex agrochemical parameters--agrochemical cultivation soil index (Icd) and basic saturation degree (V, %), which take into account some soil characteristics simultaneously, is a streamlined approach. This paper provides the equations of linear and multiple regressions, which can be used to calculate the transfer factors for 137Cs and 90Sr uptake and the herbage contamination degree for the main types of meadows of the region, that will allow reducing the volume of forage production (hay, green bulk), which is not adequate to established permissible levels: "Republican allowable levels of the contents of 137Cs and 90Sr in agricultural raw material and forages".

  6. Herbage allowance effects on the characteristics of Brachiaria brizantha cv. Marandu pastures and the production and economic viability of Nellore heifers

    Directory of Open Access Journals (Sweden)

    Alexandre Menezes Dias

    2016-09-01

    Full Text Available This study aimed to evaluate the effect of three herbage allowances (5, 10, and 15 kg dry matter [DM] 100-1 of body weight [BW] for Brachiaria brizantha cv. Marandu pastures in a continuous grazing system on the morphological and nutritional characteristics of forage, animal performance, and economic viability in Nellore heifers. The total experimental area was 60 ha, divided into 12 paddocks of 5 ha each, with 4 paddocks per treatment. The experimental animals were Nellore heifers (260 in total, with average BW of 301.16 ± 9.12 kg, receiving 0.4 % BW in multiple supplements. We evaluated the production, structural characteristics, and nutritional value of the forage, productive performance, carcass characteristics, and economic viability of each allowance. There were significant effects for the production, st uctural characteristics, and nutritional value of the forage treatment. The proportions of leaves were 42.40, 38.20, and 30.88 % and the leaf:stem ratios were 1.22, 1.03, and 0.83 for the 5, 10, and 15 kg DM 100-1 BW herbage allowances, respectively. The average daily weight gain (mean 0.42, 0.75, and 0.63 kg daily-1 and stocking rate (3.35, 1.87, and 1.26 animal unit ha-1 had a significant effect for the 5, 10, and 15 kg DM 100-1 BW forage allowance, respectively. The herbage allowances were evaluated as being economically viable with a profit margin of 10.37, 23.65, and 14.43 % for the 5, 10, and 15 kg DM 100-1 BW allowances, respectively. The greatest pasture response was found in the 5 kg DM 100-1 BW allowance and was related to better nutritional values and morphological characteristics of the pasture and greater stoking rate and weight gain per area. The herbage allowance of 10 kg DM 100-1 BW be applied to obtain higher animal performance and better economic viability of heifers in B. brizantha cv. Marandu pastures in a continuous grazing method that are receiving protein-energy supplementation.

  7. Changes in nutritive value and herbage yield during extended growth intervals in grass-legume mixtures: effects of species, maturity at harvest, and relationships between productivity and components of feed quality

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2017-01-01

    There is a lack of information on the effects of companion species in grass–legume mixtures on herbage yield and quality changes during prolonged growth. Such information is relevant for harvest planning and estimation of consequences for feeding value of conserved feed when harvesting is delayed...

  8. Características morfogênicas e estruturais e produção de forragem do capim-marandu submetido a intensidades e freqüências de desfolhação Morphogenetic and structural traits and herbage production of marandugrass under intensities and frequencies of defoliation

    Directory of Open Access Journals (Sweden)

    Kênia Régia Anasenko Marcelino

    2006-12-01

    ção de forragem com grande quantidade de folhas e menor quantidade de pseudocolmo e material morto, condicionando melhor eficiência na produção de forragem.This trial was carried out to evaluate the influence of defoliation intensities (10 and 20 cm stubble height and defoliation frequencies (three cut intervals based on the appearance of 5, 7 and 9 leaves/tiller after each defoliation event on the morphogenetic and structural traits, tillering and herbage production of Brachiaria brizantha cv Marandu swards. Treatments were allocated to experimental units according to a completely randomized design, in a 2 x 3 factorial arrangement, with three replications, in a total of 18 experimental units. Two cuts were performed in the most frequent treatment and one cut for the remaining treatments. Greater defoliation intensity resulted in greater leaf tissue turn over and, when combined to greater defoliation frequencies resulted in younger tillers, which grew up in an environment with lesser light competition. Cutting intensity at 20 cm favored tiller transition from vegetative to reproductive stage, resulting in greater contribution of pseudo stem and dead material to the herbage mass. If frequent defoliation is used, the 10 cm stubble height is the recommended intensity. If less frequent defoliation is used, the 10 cm stubble height may decrease herbage yield, mainly when using the seven leaves frequency. Greater defoliation frequencies showed greater sward renovation, with greater leaf elongation and leaf appearance rates, greater leaf blade length and lesser pseudo-stem accumulation and elongation. Although greater herbage production was obtained at the 20 cm cutting height and 7 leaves frequency, considering all evaluated traits, more frequent cuts promoted greater tissue turn over with high herbage production characterized by its high amount of leaves and less amount of pseudo stem and dead material, allowing for higher herbage production efficiency.

  9. Preliminary study on interaction between plant frictional root and rock-soil mass

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The interaction between lateral root system of woody plant and soil mass is similar to the one between shrub, herbage and soil mass, and has the effect of frictional reinforcement on slope soil. It plays an important role in reinforcing soil strength in shallow slope. Therefore, slope soil mass can be considered as a composite of soil and plant roots and the soil strength and stability of shallow slope soil mass are improved. However, current researches still remain on the level of qualitatively analyzing the relation between root and soil mass. In this paper, some exploratory researches on quantitative analysis of the interaction mechanism between root and soil mass are conducted. With the study of interaction between herbage root system (lateral root system of woody plants) and soil mass, the mechanical model of interaction between frictional root and soil mass is established. The accuracy of the model is verified by field experiments of Pinus Yunnanensis. The mechanical model provides a crucial theoretical guidance to quantitatively analyzing the interaction between plant root and soil mass; it also has certain values in application.

  10. 牧草捆裹青贮技术及其在我国的应用前景%Herbage Baled Silage Technology and Its Application Perspective in China

    Institute of Scientific and Technical Information of China (English)

    陈功

    2001-01-01

    The main research aspects and achievements on herbage baled silage technology in foreign countries were introduced, the application and popularization perspective of this type of technology in China were analysed.%概述了牧草捆裹青贮技术在国外的主要研究方向与进展,对该项技术在我国的应用和推广前景进行了分析。

  11. Interrelations between herbage yield, α-tocopherol, β-carotene, lutein, protein, and fiber in non-leguminous forbs, forage legumes, and a grass-clover mixture as affected by harvest date.

    Science.gov (United States)

    Elgersma, Anjo; Søegaard, Karen; Jensen, Søren Krogh

    2015-01-21

    Pastures with diverse botanical composition may enhance animal-derived product quality. A recent study demonstrated high vitamin concentrations and yields in some forb species. The objectives of the present study were to investigate interrelations between herbage yields, vitamin concentrations, protein and fiber contents and analyze the effect of harvest date. We hypothesized that interrelations would be similar across investigated forage species. Four nonleguminous forbs: salad burnet (Sanguisorba minor), caraway (Carum carvi), chicory (Cichorium intybus), and ribwort plantain (Plantago lanceolata), three legumes: yellow sweet clover (Melilotus officinalis), lucerne (Medicago sativa), and birdsfoot trefoil (Lotus corniculatus) and a perennial ryegrass (Lolium perenne)-white clover (Trifolium repens) mixture were sown in a field trial with two replicated and randomized blocks. Forage in 1.5 m × 9 m plots was grown in two consecutive years and cut four times per year (May-October). Analyses of variance were performed. In most herbages, α-tocopherol and β-carotene were positively correlated as were β-carotene and lutein; all vitamins were negatively correlated with fiber content and herbage yield. β-Carotene was positively correlated with protein content. α-Tocopherol and β-carotene contents were generally highest in October and lowest in July. Our results showed similar interrelationships in most investigated species, and we suggest that these species may be mixed when designing novel biodiverse mixtures for particular product quality characteristics.

  12. Effect of nitrogen fertilization rate and regrowth interval of grass herbage on methane emission of zero-grazing lactating dairy cows.

    Science.gov (United States)

    Warner, D; Podesta, S C; Hatew, B; Klop, G; van Laar, H; Bannink, A; Dijkstra, J

    2015-05-01

    Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (predominantly ryegrass) on CH4 emission from lactating dairy cows. In a randomized block design, 28 lactating Holstein-Friesian dairy cows received a basal diet of GH and compound feed [85:15; dry matter (DM) basis]. Treatments consisted of GH cut after 3 or 5 weeks of regrowth, after receiving either a low (20kg of N/ha) or a high (90kg of N/ha) fertilization rate after initial cut. Feed intake, digestibility, milk production and composition, N and energy balance, and CH4 emission were measured during a 5-d period in climate respiration chambers after an adaptation to the diet for 12d. Cows were restricted-fed during measurements and mean DM intake was 15.0±0.16kg/d. Herbage crude protein content varied between 76 and 161g/kg of DM, and sugar content between 186 and 303g/kg of DM. Fat- and protein-corrected milk (FPCM) and feed digestibility increased with increased N fertilization rates and a shorter regrowth interval. Increasing the N fertilization rate increased daily CH4 emission per cow (+10%) and per unit of DM intake (+9%), tended to increase the fraction of gross energy intake emitted as CH4 (+7%), and (partly because of the low crude protein content for the low fertilized GH) only numerically reduced CH4 per unit of FPCM. The longer regrowth interval increased CH4 emission per unit of FPCM (+14%) compared with the shorter regrowth interval, but did not affect CH4 emission expressed in any other unit. With increasing N fertilization CH4 emission decreased per unit of digestible neutral detergent fiber intake (-13%) but not per unit of digestible organic matter intake. There was no interaction of the effect of N fertilization rate and regrowth interval on CH4

  13. Recovery of strongylid third-stage larvae from herbage samples: standardisation of a laboratory method and its application in the field.

    Science.gov (United States)

    Demeler, Janina; Knapp, Friederike; Corte, Giuliano Mario; Katzschke, Oliver; Steininger, Katharina; Samson-Himmelstjerna, Georg von

    2012-03-01

    The estimation of parasitic nematode larvae present on pasture is an important tool applied in many epidemiological studies. In the face of climatic changes, there is increased interest in identifying parameters influencing the survival of free-living stages of parasites under different meteorological conditions. In order to predict possible risk factors for grazing livestock, reliable and reproducible methods to assess the density of larvae on pasture are required. A laboratory method for the recovery of strongylid third-stage larvae from herbage samples was developed, standardised and its efficacy assessed in controlled experiments as well as under field conditions. Grass samples free of any nematode larvae were used and inoculated with known numbers of third-stage larvae of Cooperia oncophora in different concentrations. The grass samples were inoculated with larvae over 24 h, followed by soaking for 4 h. The recovery process included washing over sieves and centrifugation of the obtained liquid. The total time required for the recovery process was about 5-7 h (excluding inoculation). Recovery rates range from 68% to 98% and a strong correlation between numbers of larvae added to the grass samples and numbers of larvae that could be recovered was observed (p < 0.001). The new method proved to be reproducible and provides high recovery rates combined with the potential to handle many samples simultaneously in a relatively short time, thus offering high throughput opportunities applicable to field experiments.

  14. Sward structure and livestock performance in guinea grass cv: Tanzania pastures managed by rotational stocking strategies

    Directory of Open Access Journals (Sweden)

    Valéria Pacheco Batista Euclides

    2014-12-01

    Full Text Available Grazing strategy is a key element in the determination of sward structure, herbage nutritive value and animal performance. We aimed to compare the herbage characteristics and performance of livestock in pastures of Panicum maximum cv. Tanzania managed, using two rotational stocking strategies, which provided either a fixed-length rest period (FRP of 35 days in the spring and fall and 30 days in the summer, or a variable-length rest period (VRP, determined by the time required for the canopy to achieve 70 cm in height. The pastures were evaluated in the pregrazing condition for forage mass (FM; leaf (LP, stem (SP and dead matter (DP percentages; and nutritive value (NV. The animals were weighed every 28 days. Pastures managed with the FRPs exhibited greater FMs, SPs and DPs and lower LPs and NVs than those managed with the VRPs. The average daily livestock weight gain was greater during the spring and summer for the VRP than for the FRP pastures, resulting in an average animal weight gain per area of 990 and 860 kg ha−¹ wet period−¹ for the pastures managed with the VRPs and FRPs, respectively. Thus, pasture rest periods that were maintained after the sward reached 70 cm in height reduced the animal performance on Tanzania guinea grass.

  15. Relationship between diurnal grazing time and herbage intake in dairy cows in rotational grazing Inter-relação entre o tempo de pastejo diurno e o consumo de forragem em vacas leiteiras em pastejo rotativo

    Directory of Open Access Journals (Sweden)

    Henrique Mendonça Nunes Ribeiro Filho

    2011-11-01

    Full Text Available The aim of this study was describe the relationship between grazing time and herbage intake and identify tools to grazing management of dairy cows grazing Italian ryegrass (Lolium multiflorum Lam. on a rotational grazing method. Six dairy cows in mid-lactation period were allowed to graze paddocks during three grazing cycles. During each cycle cows grazed two paddocks with 9 days of occupation by paddock and an herbage allowance of 30kg DM cow-1 day-1. Measurements were made in the last 9 days of each period and during intervals between cycles cows grazed an adjacent area with a mixed of temperate species. It was compared three grazing cycles and cows eating similar herbage amount with different daily grazing time. Independently of herbage intake, daily grazing time increased 12min by cm of the reduction on leaf height. Reductions on efficiency to graze are clearly associated to structural traits of canopy as proximity to ground level and stems + pseudo-stems content on the graze layer. In conclusion, under rotational grazing, daily grazing time is strongly associated with leaf height in the grazing layer, but it is not a good indicator of DM herbage intake. Structural traits of canopy are clearly associated with efficiency to graze, independently of daily herbage intake.Objetivou-se descrever a relação entre o tempo de pastejo e o consumo de forragem e identificar possíveis indicadores de manejo para vacas leiteiras em pastos de azevém (Lolium multiflorum Lam. no método rotativo. Foram utilizadas seis vacas leiteiras no terço médio de lactação durante três ciclos de pastejo. Em cada ciclo, os animais tiveram acesso a dois piquetes com nove dias de ocupação e oferta de forragem de 30kg MS vaca-1 dia-1. As medidas foram realizadas nos últimos nove dias de cada ciclo e, nos intervalos entre ciclos, os animais permaneceram em área adjacente com acesso a uma mistura de espécies forrageiras de clima temperado. Comparando os tr

  16. Studies of method of conserving grass herbage and frequency of feeding in cattle. 2. Eating behaviour, rumen motility and rumen fill.

    Science.gov (United States)

    Thiago, L R; Gill, M; Sissons, J W

    1992-05-01

    The influence of the method of conserving grass herbage and the frequency of feeding on eating behaviour, rumen motility and rumen fill was studied in growing steers. Silage and hay were offered to twelve rumen-cannulated Friesian steers (average initial live weight (LW) 128 kg) at a restricted level of intake (20 g dry matter (DM)/kg LW) either once or eight times daily. With once daily feeding, the daily intake of hay was consumed in a single large meal which lasted about 2 h, while silage was eaten in many small meals throughout the day. The proportion of the day spent ruminating was higher (0.39) for steers offered hay once daily than for those offered silage (0.28) or hay eight times per day (0.29). There was little effect of conservation method on frequency of rumen contraction, but contractile intensity (integration of frequency and amplitude) increased during the second half of the 24 h feeding cycle in steers offered hay either once daily or eight times daily, while the same effect was only observed when silage was offered once daily. Total daily contractile activity (the integration of the frequency and duration of myoelectric spike bursts) was significantly (P less than 0.05) higher in steers offered hay, compared with silage, once daily. The mean weight of organic matter in the reticulo-rumen of steers offered hay was significantly higher than for silage both with once (1593 v. 1326 g organic matter (OM)/100 kg LW, P less than 0.01) and eight (1367 v. 1160 g OM/100 kg LW, P less than 0.05) times daily feeding. The proportion of the particulate pool which was present as small (less than 1.2 mm) particles was always greater than 0.60.

  17. Monitoring PCDD/Fs in soil and herbage samples collected in the neighborhood of a hazardous waste incinerator after five years of operation

    Energy Technology Data Exchange (ETDEWEB)

    Nadal, M.; Bocio, A.; Schuhmacher, M.; Liobet, J.M.; Domingo, J.L. [Rovira i Virgili Univ., Reus (Spain); Diaz-Ferrero, J. [Inst. Quimic de Sarria, Barcelona (Spain)

    2004-09-15

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are among the most dangerous environmental pollutants, usually generated during combustion processes. Until recently, waste incineration was widely referenced as one of the most important sources of PCDD/F release to the atmosphere. In 1999, the only hazardous waste incinerator (HWI) in Spain began regular operations. This facility is placed in Tarragona, Catalonia. The presence of this HWI, as well as that of a municipal solid waste incinerator (MSWI) at a few kilometers, increased the concern of the public opinion in relation to the potential toxic emissions, especially those of metals and PCDD/Fs, which could affect the health of the population living in the area. Previously to regular operations (1996) the baseline levels of PCDD/Fs in soil and vegetation samples collected near the HWI were determined. A second survey was carried out two years later (1998) in order to establish the temporal variation in PCDD/F concentrations in soil and vegetation samples taken at the same sampling points. Vegetation is considered an adequate short-term environmental monitor for PCDD/Fs. Therefore, in the surveillance program of the facility (1999-2003), herbage samples (40) were annually collected at the same sampling points in which baseline samples had been taken. Moreover, considering soil as a suitable long-term monitor for PCDD/Fs, 40 soil samples in this matrix were again collected in 2001 and 2003 to examine the temporal variations of PCDD/F levels in the area. In the present study, we present the concentrations of PCDD/Fs in soil and vegetation samples collected in the vicinity of the HWI after 5 years of regular operations.

  18. Avaliação de pastagem diferida de Brachiaria decumbens Stapf. 2. Disponibilidade de forragem e desempenho animal durante a seca Evaluation of a signalgrass (Brachiaria decumbens Stapf postponed pasture. 2. Availability of herbage and animal performance, during the dry season

    Directory of Open Access Journals (Sweden)

    Eduardo Destéfani Guimarães Santos

    2004-02-01

    Full Text Available Verificaram-se as disponibilidades de forragem total, forragem verde e morta e dos componentes folha verde, caule verde, folha seca e caule seco em pastagem diferida de Brachiaria decumbens. A pastagem foi vedada à entrada dos animais de dezembro de 1996 a junho de 1997 e avaliada, sob pastejo contínuo, durante a estação seca, nos meses de julho a outubro de 1997. Também foram estudadas correlações entre características do relvado e ganho de peso de tourinhos Limousin-Nelore com 19 meses e 374 kg de peso. O diferimento da pastagem de Brachiaria decumbens proporcionou disponibilidade média de forragem (DMST de 7.568, forragem verde (DMSV de 3.834 e morta (DMSM de 3.734 kg de matéria seca (MS/ha em julho, antes do período de pastejo. A utilização contínua da pastagem diferida durante o período seco, com lotação animal de 0,75 UA/ha, não afetou a DMST, média de 7.902, e DMSM, média de 4.637 kg/ha, mas afetou a DMSV e a disponibilidade de folhas verdes (DMSFV. A DMSV e a DMSFV apresentaram taxas crescentes em julho e outubro e diminuíram a taxas crescentes em agosto e setembro. No final de setembro, as pastagens apresentaram a menor DMSV, 2.540 kg/ha. A DMSFV e a proporção de folhas verdes no relvado foram maiores no início de agosto, respectivamente, 1.517 kg/ha e 18,5%, e menores no final de setembro, 480 kg/ha e 5,7%, respectivamente. O diferimento da pastagem permitiu a manutenção dos animais e apenas pequeno ganho de peso durante a seca, média de 104 g/dia. Em setembro, os animais nas pastagens perderam peso. O ganho de peso vivo médio diário correlacionou-se linear e negativamente com DMSM e linear e positivamente com as relações [DMSV/DMSM] e [DMSFV/(DMSM + DMSCV], em que DMSCV é a disponibilidade de matéria seca de caule verde. Não foram verificadas correlações entre ganho de peso e as variáveis DMSV, DMSFV, pressão de pastejo e oferta diária de forragem.The availability of herbage, green herbage, dead

  19. Choice of grazed herbage or maize silage by lactating dairy cows: influence of sward height and concentrate level Preferência por pastagem ou silagem de milho por vacas leiteiras em lactação: influência da altura do pasto e do nível de concentrado

    Directory of Open Access Journals (Sweden)

    O. Hernandez-Mendo

    2010-10-01

    Full Text Available The preference of lactating dairy cows for grazed herbage or maize silage (MS, simultaneously offered ad libitum in the field, was examined at two sward heights (SH 4-6 and 8-10cm and two concentrate levels (CL 0 and 6kg day-1 in a 2x2 factorial arrangement within a completely randomised experimental design. The experiment lasted 35 days and was carried out in spring using 24 multiparous Holstein Friesian cows. On average, the cows proportionately spent more time grazing than eating MS (0.85:0.15 and even though the higher rate of intake (RI of dry matter (DM of MS compared with grazed herbage (76 versus 26g DM min-1, the proportion of total DM intake as herbage was higher compared to that of MS (0.56:0.44. The higher crude protein and low fibre content of grazed herbage appeared to have a higher priority of choice than RI, as the cows chose to graze for longer (grazing time 385 min, MS feeding time 67min despite the lower RI of herbage. The low proportion MS intake indicated that RI was a secondary factor of choice. Concentrate supplementation had a greater depressing effect on herbage intake than on MS intake. These results suggest that the animals reduce the intake of feed with lower RI when the labor associated to eat is decreased. The factors influencing the choice for herbage over maize silage remain unclear.A preferência de vacas leiteiras em lactação por pasto ou silagem de milho (SM oferecidas ad libitum simultaneamente no pasto foi avaliada quanto a duas alturas de pastagem (4-6 e 8-10cm e dois níveis de concentrado (0 e 6kg dia-1, em um arranjo fatorial 2x2 dentro de um delineamento inteiramente ao acaso. O experimento, com duração de 35 dias, foi executado na primavera utilizando 24 vacas multíparas da raça Holandesa. As vacas passaram, em média, proporcionalmente mais tempo pastando do que comendo SM (0,85:0,15 e, mesmo considerando a maior taxa de consumo (TC de matéria seca (MS de SM comparada com a da pastagem (76

  20. Rumen Degradability and Post-ruminal Digestion of Nitrogen and Amino acids by Cows Grazing Temperate Pasture

    Institute of Scientific and Technical Information of China (English)

    AIBIBULA; Yimamu; HALIDAI; Rehemujiang; MASAAKI; Hanada; MEIJI; Okamoto

    2015-01-01

    This experiment was conducted to evaluate nutrient digestion in the rumen and flow to the duodenum of steers grazed on orchardgrass( Dactylis glomerata L.,OG) or meadowfescue( Festuca pratensis Huds.,MF.) pastures located on northern part of Japan without supplement. Fifty-two digestion trials were carried out grazing Holstein steers fitted with cannulas in the rumen,duodenum and distal ileum in the three years. The pastures were divided into several paddocks,and the steers grazed each paddock for a day and allowed double of dry requirements the grazing cattle. The pre-grazing herbage mass did not significantly differ between pastures but the crude protein( N × 6. 25) content of herbage ranged from 19. 3% to 27. 5% on OG pasture and from 20. 0% to 32. 8% on MF pasture. Total N and AA-N intake did not differ but the degradability of dietary nitrogen in the rumen( RDN) was higher in MF than in OG pasture. The ratio of RDN to OM truly digested in the rumen was negatively related to the apparent N absorption in the rumen,and it was suggested that the amount of apparent N absorption in the rumen would be positive when the ratio was above 25 g / kg. Non-ammonia nitrogen( NAN) and AA-N flows to the duodenum of steers were lower in MF than in OG pasture. Duodenal AA flows were more linked to duodenal NAN flows and accounted for approximately 60% of duodenal NAN flows. The proportion of methionine and lysine slightly increased in the duodenal flows compared with the consumed AA,but a comparison between the essential AA composition of milk and the lean tissue indicated that duodenal digesta was most limiting in methionine,lysine,arginine,and histidine,and that deficiencies of arginine and histidine for milk production were relatively small.

  1. Substitution rate and milk yield response to corn silage supplementation of late-lactation dairy cows grazing low-mass pastures at 2 daily allowances in autumn.

    Science.gov (United States)

    Pérez-Prieto, L A; Peyraud, J L; Delagarde, R

    2011-07-01

    Feed costs in dairy production systems may be decreased by extending the grazing season to periods such as autumn when grazing low-mass pastures is highly probable. The aim of this autumn study was to determine the effect of corn silage supplementation [0 vs. 8 kg of dry matter (DM) of a mixture 7:1 of corn silage and soybean meal] on pasture intake (PI), milk production, and grazing behavior of dairy cows grazing low-mass ryegrass pastures at 2 daily pasture allowances (PA; low PA=18 vs. high PA=30 kg of DM/cow above 2.5 cm). Twelve multiparous Holstein cows were used in a 4 × 4 Latin square design with 14-d periods. Pre-grazing pasture mass and pre-grazing plate meter pasture height averaged 1.8 t of DM/ha (above 2.5 cm) and 6.3 cm, respectively. The quality of the offered pasture (above 2.5 cm) was low because of dry conditions before and during the experiment (crude protein=11.5% of DM; net energy for lactation=5.15 MJ/kg of DM; organic matter digestibility=61.9%). The interaction between PA and supplementation level was significant for PI but not for milk production. Supplementation decreased PI from 11.6 to 7.6 kg of DM/d at low PA and from 13.1 to 7.3 kg of DM/d at high PA. The substitution rate was, therefore, lower at low than at high PA (0.51 vs. 0.75). Pasture intake increased with increasing PA in unsupplemented treatments, and was not affected by PA in supplemented treatments. Milk production averaged 13.5 kg/d and was greater at high than at low PA (+1.4 kg/d) and in supplemented than unsupplemented treatments (+5.2 kg/d). Milk fat concentration averaged 4.39% and was similar between treatments. Milk protein concentration increased from 3.37 to 3.51% from unsupplemented to supplemented treatments, and did not vary according to PA. Grazing behavior parameters were only affected by supplementation. On average, daily grazing time decreased (539 vs. 436 min) and daily ruminating time increased (388 vs. 486 min) from 0 to 8 kg of supplement DM. The PI

  2. Consumo e tempo diário de pastejo por novilhos Nelore em pastagem de capim-tanzânia sob diferentes ofertas de forragem Effects of herbage allowance on the intake and grazing time of Nellore steers grazing tanzâniagrass pasture

    Directory of Open Access Journals (Sweden)

    Miguel Marques Gontijo Neto

    2006-02-01

    allowance (HA (kg of leaf blade /100 kg animal live weight/day, % were: 6.1 ± 0.59; 11.1 ± 0.77; 18.0 ± 1.24 and 23.9 ± 1.15%. Eight Nelore animals averaging 229.0 and 249.5 kg grazed each paddock in the first and second sampling periods, respectively. A completely randomized block design was used. Grazing time, leaf dry matter availability, leaf:stem ratio and canopy height were highly correlated with forage intake and can be used to develop prediction models of forage intake and performance of the grazing animal. Studies on intake and grazing animal performance in relation to forage allowances should consider the pasture structural traits for data interpretation and comparison. Tanzaniagrass forage allowances induced changes in the pasture structural characteristics and had quadratic effect on the daily grazing time and on the forage intake by Nelore steers. Shortest grazing time and highest forage intake were observed on pasture with herbage allowance of about 22.5 kg leaf blade/100 kg BW, which corresponded to a post-grazing mass of 4323.2 kg/ha dry matter, 2887.6 kg/ha dry green matter and average canopy height of 64 cm.

  3. Rest mass or inertial mass?

    OpenAIRE

    Khrapko, R. I.

    2001-01-01

    Rest mass takes the place of inertial mass in modern physics textbooks. It seems to be wrong. But this phenomenon is hidden away by the facts that rest mass adherents busily call rest mass "mass", not rest mass, and the word "mass" is associated with a measure of inertia. This topic has been considered by the author in the article "What is mass?" [1, 2, 3]. Additional arguments to a confirmation of such a thesis are presented here.

  4. Produção e qualidade de pastagens de Coastcross-1 e milheto utilizadas com vacas leiteiras Production and quality of Coastcross-1 and pearl millet pastures utilized with dairy cows

    Directory of Open Access Journals (Sweden)

    Luciene Fernanda Barros Scaravelli

    2007-06-01

    detergent fiber (NDF. No significant difference (P>.05 was observed to DMA, DMR, TDM and CP. Pearl millet presented greater availability of LB (P<.05, smaller NDF (P<.05 in pregraze and postgraze herbage mass and greater contribution of OS (P<.05. The total grazing period was greater in Coastcross-1 pasture.

  5. Research Advances in Herbage Plant Phenology and Phenological Model of Grassland%草本植物物候及其物候模拟模型的研究进展

    Institute of Scientific and Technical Information of China (English)

    符瑜; 潘学标

    2011-01-01

    草地生态系统在全球变化过程中具有不容忽视的作用.为深入了解草本植物物候与气候因素间的相互作用机制,建立精确的草地植被物候动态模型,更好地模拟和预测天然草地生态系统对气候变化的响应,本文对国内外草本植物物候及有关草本植物物候模型研究进行了回顾.已有的研究表明物候变化能在一定程度上反映出气候变化的趋势,且温度、光照和水分等环境因素作为物候的主要驱动力在不同的时期发挥着重要的作用.植物物候模型从简单统计模型,逐渐向可描述生长与环境相互作用过程的动态机理模型发展.但可用于天然草地植被物候模拟的模型较少,仍存在物种单一、适用范围小、缺少机理性研究等问题.针对目前的研究现状,只有加强对天然草地植被物候与非生物因子关系的分析,特别是水分对物候的影响研究,努力探索各个物候期的生理特征,不断验证完善已有物候模型,才能建立起精确的草地植被物候模型服务于全球气候变化的研究.%Grassland ecosystems are unassailable associated with global change. In this paper we summarized the research advances in herbage plant phenology and phenological model of grassland. We searched many literatures and found that the changes of plant phenology could reflect some effects of climate change directly. The environmental driving factors such as temperature, light and water would have different effects in controlling the progress of phenology. The development of plant phenological model had strong trends toward dynamic phenological model based on plant development mechanism from statistical model in the beginning. However,less was known about natural grassland phenological model. Some existing phenological models only could be used for specific species simulation,some couldn't be used for large-scale region, and the others were lack of description in development

  6. Effects of Cutting Period on Herbage Yield and Quality of Cut-grassland at Zhaosu Horse Ranch%刈割时期对昭苏马场人工割草地产量和品质的影响

    Institute of Scientific and Technical Information of China (English)

    阿依古丽·达嘎尔别克; 阿布都卡哈尔·阿布都卡迪尔; 哈丽代·热合木江; 艾比布拉·伊马木

    2013-01-01

    The cut-grassland in Zhaosu Horse Ranch of Yili Kazakh Autonomous Prefecture of Xinjiang were harvested in July and August of 2013. The grass yield and forage quality were analyzed. The results showed that the cutting period had no obvious effect on the yields of fresh grass and hay in cut-grasslands that had been established for third years and seventh years. The crude protein content in the forage that was cut in August was significantly decreased than that in July (P<0.05). The proportion of leguminous plants in the cutting herbage had no significant changes with the cutting period,but leaf-stem ratio was significantly decreased in August (P<0.01). The content of neutral detergent fiber and acid detergent fiber in the forage cut in August was increased in different degrees (P<0.05). Therefore, the reasonable cutting period for Zhaosu Horse Ranch′s cut-grassland was in early and middle stages of July, the forage yield and quality were better.%分别于2013年7月上中旬和8月上中旬对新疆维吾尔自治区伊犁哈萨克自治州昭苏马场人工割草地进行刈割,并进行了产草量测定和牧草品质的比较分析。结果表明,刈割时期对建植第3年和第7年割草地的鲜草和干草产量无明显影响;8月上中旬刈割牧草的粗蛋白(CP)含量与7月上中旬刈割牧草相比显著降低(P<0.05);刈割牧草中,豆科牧草的比例无明显变化,但8月上中旬刈割牧草的叶茎比显著降低(P<0.01);在8月上中旬刈割的牧草中,中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量有不同程度的增加(P<0.05)。由试验可知,昭苏马场的合理割草时间以7月上中旬为宜,此时牧草的产量和质量较佳。

  7. Discussion on the strategic status of herbage in the sustainable development of prataculture based on the pratacultural model of Guangdong Province%从广东草业生产模式看牧草在可持续发展中的战略地位

    Institute of Scientific and Technical Information of China (English)

    陈三有

    2000-01-01

    通过对广东草业主要生产模式的分析研究,指出牧草在充分利用资源,缓解粮食紧张问题,提高地力,治理水土流失,改善生态环境等方面的作用,进而阐述了草业对可持续发展的重要性。%The role of herbage in sufficient utilization of resources, solution of food shortage, increase in soil fertility and improvement of ecological environment were disscussed after studying the main productive model of prataculture in Guangdong Province. Thereby the significance of prataculture in sustainable development was analyzed.

  8. Farelo de glúten de milho para vacas leiteiras em pastos de azevém anual Corn gluten meal to dairy cows grazing italian ryegrass

    Directory of Open Access Journals (Sweden)

    Henrique Mendonça Nunes Ribeiro Filho

    2009-07-01

    . Cows were distributed in four groups (two per treatment and assigned to Italian ryegrass plots submitted to intermittent grazing with a herbage allowance of 24kg of DM cow day-1. Pre-grazing herbage mass (2325kg of DM ha-1 and sward surface height (15.8cm were similar on plots and crude protein and NDF of ingested forage were 18.9 and 53,0%, respectively. Supplementation did not affect herbage DM intake (mean=8.5kg cow day-1 but, both, total DM intake and metabolisable energy increased 3.0kg and 42MJ cow day-1, respectively. Supplementation increased milk production (4.0 kg.cow.day-1 but did not change protein and fat milk content (32.8 and 29.2g kg-1. At low herbage allowance, supplementation with corn ground meal (22% of crude protein increase milk production on proportion of 1:1 and studies should be done at conditions of non- limitant herbage allowance.

  9. Axino mass

    CERN Document Server

    Kim, Jihn E

    2012-01-01

    I will talk on my recent works. Axino, related to the SUSY transformation of axion, can mix with Goldstino in principle. In this short talk, I would like to explain what is the axino mass and its plausible mass range. The axino mass is known to have a hierarchical mass structure depending on accidental symmetries. With only one axino, if G_A=0 where G=K+ 2ln|W|, we obtain axino mass= gravitino mass. For G_A nonzero, the axino mass depends on the details of the Kaehler potential. I also comment on the usefulness of a new parametrization of the CKM matrix.

  10. Componentes da Produção de Forragem em Pastagens dos Capins Tanzânia e Mombaça Adubadas com Quatro Doses de NPK Components of Herbage Production of Tanzania and Mombaça Pastures Fertilized with Four Doses of NPK

    Directory of Open Access Journals (Sweden)

    Danilo Gusmão de Quadros

    2002-06-01

    height of residue of 30 cm. A complete randomized block design was used with treatments arranged in a 2 x 4 factorial with three field replications. The fertilization doses corresponded to the reduction of 30 % and the increase of 30 and 60% in relation to a standard dose of 145; 21.6; and 180 kg/ha of N, P2O5, and K2O, respectively (assuming the contents of 1.2, 0.08, and 1.2% of N, P, and K in DM, to reach an estimated DM production of 12000 kg/ha. There was a linear effect of fertilization doses on green DM (GDM before and after grazing. The cv. Mombaça exhibited higher herbage mass before and after grazing (9183 and 5279 kg/ha of GDM, respectively than the cv. Tanzania (6275 and 3808 kg/ha of GDM, respectively. The proportion of leaf blade in the GDM available was lower in the cv. Tanzania (51% than in the cv. Mombaça (54 %. The tiller density was not affected by the fertilization doses. However, the increase in tiller weight due to fertilizer doses was responsible for the higher GDM production. The senesced DM did not vary between cultivars, with a mean value of 3108 kg/ha. In general, higher rates of fertilization resulted in greater GDM accumulation rate and higher losses of GDM by trampling. The cv. Mombaça showed a greater response potential to fertilization than the cv. Tanzania with stocking rates of 6.2 and 4.0 UA/ha, respectively.

  11. Abdominal mass

    Science.gov (United States)

    Mass in the abdomen ... care provider make a diagnosis. For example, the abdomen can be divided into four areas: Right-upper ... pain or masses include: Epigastric -- center of the abdomen just below the rib cage Periumbilical -- area around ...

  12. Neutrino Masses

    CERN Document Server

    Weinheimer, Christian

    2013-01-01

    The various experiments on neutrino oscillation evidenced that neutrinos have indeed non-zero masses but cannot tell us the absolute neutrino mass scale. This scale of neutrino masses is very important for understanding the evolution and the structure formation of the universe as well as for nuclear and particle physics beyond the present Standard Model. Complementary to deducing constraints on the sum of all neutrino masses from cosmological observations two different methods to determine the neutrino mass scale in the laboratory are pursued: the search for neutrinoless double $\\beta$-decay and the direct neutrino mass search by investigating single $\\beta$-decays or electron captures. The former method is not only sensitive to neutrino masses but also probes the Majorana character of neutrinos and thus lepton number violation with high sensitivity. Currently quite a few experiments with different techniques are being constructed, commissioned or are even running, which aim for a sensitivity on the neutrino ...

  13. MASS SPECTROMETER

    Science.gov (United States)

    White, F.A.

    1960-08-23

    A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

  14. Effects of post-grazing forage mass on a beef cattle grazing system on Tanzânia grass pastures

    Directory of Open Access Journals (Sweden)

    Marco Antonio Penati

    2014-06-01

    Full Text Available The objective of this study was to evaluate the effect of grazing intensity on herbage accumulation, animal performance, and total system yield on irrigated Tanzania grass pastures under rotational stocking. The experiment was conducted from October 1999 to January 2001, in a complete randomized block design with four replications. Treatments consisted of three grazing intensities, represented by the following quantities of green forage dry mass remaining after grazing: 1,000 (high intensity, 2,500 (intermediate intensity and 4,000 (low intensity kg ha−1. Grazing cycles were of 36 days (33 rest and 3 grazing. The values observed at the end of the experiment for post grazing forage mass were close to the proposed values. Forage yield was 25,278, 36,850, and 34,144 kg DM ha−1, whereas animal performance was 0.398, 0.541, and 0.564 kg BW day−1for high, intermediate and low intensities, respectively. Grazing intensity was positive related to the stocking rate (6.5, 5.2 and 4.1 AU ha−1 at high, intermediate and low intensities, respectively. Total system yield was not affected by treatments, ranging between 1,518 and 1,287 kg BW ha−1 year−1.

  15. Carbon Catabolic Characteristics About the Soil Dominant Bacteria from 'Hanfu' Apple Orchard with Herbage-mulching Management%生草覆盖‘寒富’苹果园土壤优势细菌的碳代谢特征研究

    Institute of Scientific and Technical Information of China (English)

    刘灵芝; 吕德国; 秦嗣军; 马怀宇; 杜国栋; 刘国成

    2011-01-01

    In order to explore the effects of land management on the carbon catabolic characteristics of soil microorganisms, the carbon catabolic characters and community structure of soil bacteria in different periods about 'Hanfu' apple orchard with the herbage-mulching management was investigated in this study. The results showed that the amount and ability for soil bacteria to use carbon sources in June and July were significantly higher than that in April, May, August and September. Compared to clean tillage treatment, the herbage-mulching treatment decreased 1 strain of dominant bacteria in April, increased 1 strain in September, and showed no differences from May to August. In general, dominant bacterial strains isolated from the herbage-mulching treatment obviously enhanced the ability to utilize carbohydrates (such as sucrose, glucose and starch), ethonhol inols (such as sorbitol and lnOSltol), and amino acids (such as aspartic acid and leucine) in the different periods except for April. The analysis of 16S rDNA sequence showed that 53.8% of the dominant bacteria belonged to Bacillus, which existed in most of the tested soils. Alcaligenes, Pseudomonas and Firmicutes would also become the dominant genera in different tested soils because of the influences of different seasons and different management measures. Compared to the soil sampled in April, May, August and September, in the soil sampled in June and July two dominant genera including Alcaligenes and Firmicutes were increased; And compared to the clean tillage, the herbage-mulching treatment increased Firmicutes and some uncultured soil bacteria in July.%为了解土壤管理制度对果园土壤微生物碳代谢特征的影响,研究了生草覆盖‘寒富’苹果园不同时期土壤优势细菌碳代谢功能及种群组成。结果表明,6月、7月土壤中优势细菌数量及碳代谢能力明显高于4月、5月、8月和9月。生草覆盖处理4月分离到的优

  16. Mass metrology

    CERN Document Server

    Gupta, S V

    2012-01-01

    This book presents the practical aspects of mass measurements. Concepts of gravitational, inertial and conventional mass and details of the variation of acceleration of gravity are described. The Metric Convention and International Prototype Kilogram and BIPM standards are described. The effect of change of gravity on the indication of electronic balances is derived with respect of latitude, altitude and earth topography. The classification of weights by OIML is discussed. Maximum permissible errors in different categories of weights prescribed by national and international organizations are p

  17. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained r...

  18. Efecto del nivel de suplementación con concentrado sobre la respuesta productiva en vacas lecheras a pastoreo primaveral con alta disponibilidad de pradera Effect of the level of concentrate supplementation on the productive response of dairy cows on spring grazing receiving a high herbage allowance

    Directory of Open Access Journals (Sweden)

    RG Pulido

    2009-01-01

    Full Text Available Se realizó un experimento con el objeto de evaluar el efecto de distintos niveles de suplementación con concentrado, sobre el comportamiento productivo de vacas lecheras a pastoreo primaveral, recibiendo una generosa oferta de pradera. Se usaron 28 vacas Frisón Negro, las que fueron asignadas a los siguientes tratamientos: SP, sólo pastoreo; PSC3, pastoreo más 3 kg de concentrado; PSC6, pastoreo más 6 kg de concentrado y PSC9, pastoreo más 9 kg de concentrado. Las vacas fueron suplementadas dos veces al día y manejadas en pastoreo rotativo. En cada vaca el peso vivo y la condición corporal fueron registrados semanalmente y la producción láctea diariamente. La composición de la leche se analizó semanalmente. Semanalmente a cada animal se tomaron muestras de sangre para determinar las concentraciones plasmáticas de βOH-butirato, NEFA, urea y albúminas. La producción láctea fue de 28,1; 30,8; 31,2 y 28,8 L/día, para los tratamientos SP, PSC2, PSC3 y PSC4, respectivamente (P > 0,05. Las concentraciones lácteas de proteína o urea no fueron afectadas por los tratamientos. La suplementación disminuyó en un 0,57% las concentraciones de grasa en leche (P The purpose of this study was to evaluate the effect of different levels of concentrate supplementation on the productive response of dairy cows fed high daily herbage allowance of spring pasture. The study was conducted from September to November of 2005. Twenty eight spring calving Friesian cows were assigned to four treatments: SP, grazing alone; PSC3, pasture plus 3 kg/d of concentrate; PSC6, pasture plus 6 kg/d and PSC9, pasture plus 9 kg/d of concentrate. The cows were supplemented twice a day and managed under a strip grazing system. Weight and body condition were recorded individually each week. Milk production was recorded individually on a daily basis and composition was analyzed each week. Coccigeal blood samples from each cow were obtained each week after the morning

  19. Estimation of diet composition and herbage intake of grazing sheep at different stocking rates in Inner Mongolia typical steppe by using n-alkanes technique%链烷技术估测典型草原不同放牧率绵羊食性食量方法研究

    Institute of Scientific and Technical Information of China (English)

    刘贵河; 张英俊; 汪诗平; 韩建国

    2013-01-01

    为了进一步探讨饱和链烷技术在典型草原自由放牧家畜中的应用,定量研究自由放牧绵羊食性及食量,于2004年6-9月在中国科学院内蒙古草原生态系统定位研究站放牧样地进行试验,选择体重及体况相近、健康无病的二岁羯羊(内蒙古细毛羊×蒙古羊)60只,按体重(36.9±2.6) kg聚类分组,设置6种放牧率(0,1.33,2.67,4.00,5.33和6.67羊/hm2)的轮牧实验,绵羊采食量的测定选择放牧率为1.33,4.00和6.67羊/hm2的处理,试验开始,每只羊投喂1粒QSM饱和链烷缓释胶囊.食性测定选用全部的放牧率进行,同时辅助全粪法、扣笼法一同评价.试验期内定期收集试验地牧草样品及绵羊粪便样品,使用气相色谱分析牧草和粪样中的链烷含量,应用链烷技术估测放牧绵羊的排粪量、牧草采食比例和干物质采食量.结果表明,植物链烷模式存在种间差异,运用链烷技术估测的排粪量和实际测得排粪量差异不显著(P>0.05),放牧绵羊主要采食7~9种牧草,且不同放牧季节不同放牧率绵羊采食的牧草种类和比例不同,但采食量差异不显著(P>0.05).本研究表明,运用链烷技术结合扣笼方法可以估测天然草地自由放牧家畜牧草的采食比例、干物质采食量和排粪量.%In order to probe into the application of n-alkanes as markers for estimating diet composition and herbage intake of free grazing herbivores in rangeland, a rotational grazing experiment was conducted from 20th June to 20th September at 2004, at the Inner Mongolia Grassland Ecosystem Research Station of Chinese Academy of Sciences. Sixty 2-year-old wethers (Inner Mongolia fine wool sheep × Inner Mongolia sheep) were selected and allocated to the 5 stocking rates (1. 33, 2. 67, 4. 00, 5. 33 and 6. 67 sheep/ha) without significant difference (P>0. 05) in body weight (36. 9±2. 6) kg to evaluate the effect of stocking rates and grazing seasons on dietary composition and intake

  20. Mass Media

    Institute of Scientific and Technical Information of China (English)

    叶全荣

    2006-01-01

    @@ Every day,we are all influenced by the mass media.Although some critics of the media claim that these means of communication are used mainly to control our thinking and get us to buy products that we don't need,the media also contribute to keeping people informed.In other words,while dangers do exist,the benefits of the media far outweigh(超过)the disadvantages.Most of the messages brought to viewers,listeners,and readers are designed either to inform or to entertain,and neither of these goals can be considered dangerous or harmful.

  1. Critical Mass

    CERN Multimedia

    AUTHOR|(CDS)2070299

    2017-01-01

    Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. At CERN it is held once a year in conjunction with the national Swiss campaing "Bike to work".

  2. Binary mass ratios: system mass not primary mass

    CERN Document Server

    Goodwin, Simon P

    2012-01-01

    Binary properties are usually expressed (for good observational reasons) as a function of primary mass. It has been found that the distribution of companion masses -- the mass ratio distribution -- is different for different primary masses. We argue that system mass is the more fundamental physical parameter to use. We show that if system masses are drawn from a log-normal mass function, then the different observed mass ratio distributions as a function of primary mass, from M-dwarfs to A-stars, are all consistent with a universal, flat, system mass ratio distribution. We also show that the brown dwarf mass ratio distribution is not drawn from the same flat distribution, suggesting that the process which decides upon mass ratios is very different in brown dwarfs and stars.

  3. Características do pasto e acúmulo de forragem em capim-tanzânia submetido a alturas de manejo do pasto Sward characteristics and herbage accumulation of Tanzania grass submitted to sward heights

    Directory of Open Access Journals (Sweden)

    Marcos Weber do Canto

    2008-03-01

    Full Text Available O objetivo deste experimento foi avaliar alturas de manejo do pasto (20, 40, 60 e 80 cm em capim-tanzânia (Panicum maximum Jacq., em regime de lotação contínua, nas características do dossel e acúmulo de matéria seca. Os animais utilizados foram novilhos Nelore (Bos indicus, e a taxa de lotação foi variável. Foram avaliados: a massa de forragem, a massa de lâmina de folha verde, a razão folha:colmo, a composição morfológica e a taxa de acúmulo de matéria seca. O delineamento experimental foi inteiramente casualizado, com duas repetições. A massa de forragem aumentou linearmente com o aumento da altura do pasto. As médias de massa de forragem foram 2.767, 3.105, 3.657 e 4.436 kg ha-1, respectivamente, para as alturas de 20, 40, 60 e 80 cm. As taxas de acúmulo de matéria seca, a 20, 40, 60 e 80 cm, foram, respectivamente, 104, 108, 90 e 81 kg ha-1 por dia, o que indica que houve redução dessas taxas com a elevação da altura do pasto. A razão folha:colmo decresceu linearmente com o aumento da altura do pasto. Pastagens de capim-tanzânia, sob lotação contínua ao final da primavera e durante o verão, devem ser utilizadas entre 40 e 60 cm de altura.The objective of this experiment was to evaluate different sward height (20, 40, 60 e 80 cm in Tanzania grass (Panicum maximum Jacq. pastures managed under continuous stocking. The animals used were Nellore steers, and the control of sward height was done with put-and-take techniques. Evaluations were made for: forage mass, green leaf mass, leaf:stem ratio, morphological composition and dry matter accumulation rate. The experimental design was completely randomized with two replications. Forage mass increased linearly with sward height with overall mean of 2,767, 3,105, 3,657 and 4,436 kg ha-1 at sward heights 20, 40, 60 and 80 cm, respectively. Rates of dry matter accumulation decreased with increasing sward heights and were 104, 108, 90 and 81 kg ha-1 per day for sward

  4. 牧草种子热泵辅助型太阳能储热干燥设备设计与试验%Design and Experiment of Heat Pump Assisted Solar Energy Heat-storage Drying Equipment for Herbage Seed

    Institute of Scientific and Technical Information of China (English)

    王全喜; 王德成; 杜建强; 翟改霞

    2012-01-01

    Aiming at herbage seed drying equipment problems of power consumption, air discharge and solar energy application, a drying mode was proposed. Basis heating was supplied by thermal-stored solar energy, and air charge was dehumidified and reused by heat pump. Main working parts, such as thermal collector, thermal storage and heat pump, and whole drying machine were designed. Using movable design idea, thermal collector was controllable and whole machine was placed safely. Performance test results showed that handling capacity reached to 161 kg/h, power handling capacity achieved to 8. 4 kg/ ( kW · h) , the drying capacity reached to 3 367 kg · % /h, and dry strength achieved to 6. 7 kg/ ( m3 · h). The power consumption ration of solar PCM heat-storage drying, solar energy and heat pump teamwork drying, heat-pump drying and electricity power drying was 0. 9:1.0:1.2:1. 5.%针对牧草种子干燥设备在能耗、排放和太阳能使用等方面存在的问题,提出了太阳能储热供热为主,尾气由热泵除湿后回收使用为辅的节能零排放干燥模式,完成了集热、储热和热泵等主要工作部件以及整机的结构设计,用移动式设计实现了太阳能集热可控和整机安全贮存.试验结果表明:处理量161 kg/h,度电处理量8.4 kg/(kW·h),干燥能力3 367 kg·%/h,干燥强度6.7 kg/(m3 ·h);太阳能相变储热干燥、太阳能一热泵联合干燥、热泵干燥和电加热干燥4种供热干燥模式的耗电量之比是0.9:1.0:1.2:1.5.

  5. Characteristics of herbage water soluble carbohydrates and of factors influencing them%牧草中水溶性碳水化合物及其影响因素

    Institute of Scientific and Technical Information of China (English)

    黄德君; 毛祝新; 傅华

    2011-01-01

    Water soluble carbohydrates (WSC) are one of the basic metabolic materials in plants and they influence plant growth, development and adaptability to harsh environments. In addition, an increase in WSC content can enhance the use efficiency of protein and dry mass in forage by herbivores, thereby not only enhancing protein production in milk, but also reducing CO2 emissions from the animal's rumen. In this paper, we summarize the characteristic of WSC in the plant influenced by the biotic and abiotic factors such as heredity, environment, and cultivation management. WSC contents of plants differed between plant species, organ positions and phonological phases. Environmental factors such as temperature, water, salt and nutrition contents also had major influences on WSC content.%水溶性碳水化合物是参与植物体新陈代谢的基本物质之一,其在植物体内的高低影响到植物的生长发育及植物生态适应能力.另外,提高牧草中水溶性碳水化合物的含量可以促进反刍动物对瘤胃内蛋白质的利用和干物质的吸收,不仅提高了奶蛋白产量,而且减少了温室气体的排放.因此,本研究综述了遗传、环境及草地管理等对牧草中水溶性碳水化合物含量及其在牧草体内运转与分配的影响,牧草体内水溶性碳水化合物含量的变化受到植物种类、取样部位和不同生长时期的影响.另外,其在植物体内的含量随温度、水分、盐等非生物因素及营养元素供应的改变亦有明显不同.

  6. Componentes da biomassa pré-pastejo e pós-pastejo de capim-tanzânia sob lotação rotativa com quatro níveis de suplementação concentrada Pre- and post-grazing biomass components of tanzania grass under intermittent stocking with four concentrate supplementation levels

    Directory of Open Access Journals (Sweden)

    Roberto Cláudio Fernandes Franco Pompeu

    2008-03-01

    design, with SL being plots and grazing cycles (GC subplots, with four replicates. Total herbage dry mass (MSFT, death herbage dry mass (MSFM, green herbage dry mass (MSFV, green leaf blade dry mass (MSLV, green stem dry mass (MSCV, canopy height (ALT; number of live leaf per tiller (F/P, leaf/stem (F/C and live/death material (MV/MM ratios, pre- and post-grazing, as well as the tiller populational density (DPP pre-grazing and residual leaf area index (IAFres were determined. Considering pre-grazing biomass components, it was not observed significative effects between SL and GC to F/P, MSFM, MSFV, MV/MM, MSLV and, MSCV. For canopy height, it was observed difference between cycle 4 compared to others. The MSFT was affected by SL, where the sheeps supplemented with 0.6% LW was similar to the ones supplemented with 0.0 and 1.8% LW levels, however at the 0.6% LW level, MSFT was greater than 1.2% LW. There were no effects of SL and cycles on MSFTres and MSFMres. It was not observed differences among 0.0, 0.6 and 1.8% SL on MSFTres and MSFMres, however the 0.6% SL (LW was greater than 1.2% SL (LW. There was a squared effect of SL on MSFVres, however, there was no observed effect of cycles. It was not observed effect of SL and GC on the MV/MMres relation. It was observed a squared effect of SL on the MSLVres and IAFres. There was a squared effect of SL on the MSCVres. The addition of SL caused increase in F/Cres. It was not observed effect of SL on DPP. The SL did not affect the pasture regrowth vigor, because of the maintenance of biomass components in accepted levels.

  7. 草本能源植物培育及催化制备先进液体燃料%Advanced Liquid Fuel Production by Herbage Energy Plant Breeding and Catalytic Transformation

    Institute of Scientific and Technical Information of China (English)

    马隆龙; 刘琪英

    2016-01-01

    obtaining the yield of high phenolic monomers, the cooperative promotion mechanism of lignin decompolymerization by oxidation and liquifaction was investigated under microwave irradiation. (3) For the third key scientific issue, the study focused on the H2 production by decomposed products of biomass, the liquid alkane fuels and oxygen contained fuels from sugar derivatives by catalysis, and the liquid alkane fuels by phenol derivatives. The stimulated process was established based on the principle of Gibbs energy minimization and the hydrothermal gasification model and conversion pathway of glucose aqueous solution. The catalysts contained Ni/CeO2-Al2O3 and Ni/TiO2 were prepared, characterized and their performance was tested in H2 production by glucose aqueous solution, which obtained the H2 yield of more than 90% and good catalytic stability. For the first time,we found that the mdtB gene significantly affects the stress resistance and growth rate of the fungus, and thus influences the H2 production rate. The mass transfer enhanced micro- liquid layer system was developed to achieve high yielded HMF and alditol by one-pot conversion of sugar derivatives and the effective catalysts included functionalized nano-carbon and metal sulfates and phosphates were designed to the selective cracking of bonds in sugar derivatives. To obtain the high yield of liquid alkanes from sorbitol conversion in aqueous phase, the highly active metal supported on micro-/meso-porous zeolite was fabricated and the detailed reaction mechanism and pathway for products formatiion were researched. The pilot scaled apparatus for liquid alkanes production from sugar derivatives has been built up on the basis of scientific investigation in lab. To achieve the simultaneous conversion of cellulose and hemi-cellulose to platform (furfural, HMF and levulinic acid, etc.), the new catalysts were developed and the formation mechanism and product controlling pathway was clarified. The effective duel

  8. Mass Customization Services

    DEFF Research Database (Denmark)

    Friedrich, Gerhard

    Topics of the IMCM’08 & PETO’08 and this book are: Mass customization in service, mass customizing financial services, mass customization in supply networks, implementation issues in logistics, product life cycle and mass customization. The research field of mass customization is more than 15 years...

  9. Simulation of water use and herbage growth in arid regions

    NARCIS (Netherlands)

    Keulen, van H.

    1975-01-01

    The and and semi-arid regions of the world, totalling about 30% of the land surface of the earth, are predominantly used for extensive grazing, as low and erratic rainfall presents too high a risk for arable farming. The population that can be sustained by the animal products -meat, milk or wool- is

  10. herbage mineral nutrition indexed as tools for rapid mineral status ...

    African Journals Online (AJOL)

    Administrator

    The animal production sector in the tropics is increasingly becoming challenged with the ... nine farms, with swards made of either temperate or tropical grasses, grazed or mowed, were visited between ..... Cycling in Agroecosystem 47:59-69.

  11. GROWTH AND HERBAGE OF TELFAIRIA OCCIDENTALIS (HOOK F).

    African Journals Online (AJOL)

    DR. AMINU

    2013-06-01

    Jun 1, 2013 ... Heavy metals (Va and Pb) concentration increased with increasing concentration of spent engine oil. Amendment of spent engine oil polluted soil with organic fertilizer .... MATERIALS AND METHODS. Experimental Design.

  12. The local mass density

    Science.gov (United States)

    Veeder, G. J.

    1974-01-01

    An improved mass-luminosity relation for faint main-sequence stars derived from recently revised masses for some faint double stars is presented. The total local mass density is increased to nearly 0.2 solar masses per cu pc. This estimate is as large as the mass density required by Oort's (1965) dynamical analysis of stellar motions perpendicular to the galactic plane if the mass is concentrated in a narrow layer.

  13. Potential of imaging spectroscopy as tool for pasture management

    NARCIS (Netherlands)

    Schut, A.G.T.; Lokhorst, C.; Hendriks, M.M.W.B.; Kornet, J.G.; Kasper, G.J.

    2005-01-01

    The use of imaging spectroscopy to predict the herbage mass of dry matter (DM), DM content of herbage and crude fibre, ash, total sugars and mineral (N, P, K, S, Ca, Mg, Mn, Zn and Fe) concentrations was evaluated. The experimental system used measured reflectance between 404 and 1650 nm at high spa

  14. Mass Function of Low Mass Dark Halos

    CERN Document Server

    Yahagi, H; Yoshii, Y; Yahagi, Hideki; Nagashima, Masahiro; Yoshii, Yuzuru

    2004-01-01

    The mass function of dark halos in a Lambda-dominated cold dark matter (LambdaCDM) universe is investigated. 529 output files from five runs of N-body simulations are analyzed using the friends-of-friends cluster finding algorithm. All the runs use 512^3 particles in the box size of 35 h^{-1}Mpc to 140 h^{-1}Mpc. Mass of particles for 35 h^{-1} Mpc runs is 2.67 times 10^7 h^{-1} M_{solar}. Because of the high mass resolution of our simulations, the multiplicity function in the low-mass range, where the mass is well below the characteristic mass and $\

  15. Mass spectrometric immunoassay

    Science.gov (United States)

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2007-12-04

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  16. Heavy quark masses

    Science.gov (United States)

    Testa, Massimo

    1990-01-01

    In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.

  17. Produção e qualidade de forragem da mistura de aveia e azevém sob dois métodos de estabelecimento Forage production and quality of oats and ryegrass mixture under two establishment methods

    Directory of Open Access Journals (Sweden)

    Marta Gomes da Rocha

    2007-02-01

    Full Text Available Neste trabalho, comparou-se a sobre-semeadura de aveia (Avena strigosa Schreb. e azevém (Lolium multiflorum Lam. em pastagem de coastcross (Cynodon dactylon (L. Pers. ao cultivo estreme como métodos de implantação de pastagens de inverno em sistema de pastejo rotacionado com vacas holandesas em lactação. Foram avaliados a produção total de MS (PTF, a massa de forragem de entrada (MFE, o resíduo (RES, as perdas de forragem (PD, a taxa de acúmulo diário de MS (TAD, a carga animal (CA, a oferta de forragem (OF e a biomassa de lâminas foliares (BLF. Para determinação da composição botânica, foram separados em cada espécie (aveia, azevém e coastcross os componentes estruturais folha, colmo e material senescente. Na entrada e saída dos animais da pastagem, foram colhidas amostras por simulação de pastejo para determinação dos teores de PB e FDN. Não houve diferença entre tratamentos para PTF, MFE, RES, PD, TAD, OF e CA. A oferta média de lâminas foliares foi de 1,3±0,67 kg LF/100 kg PV. A sobre-semeadura proporcionou maior biomassa de lâminas foliares disponibilizando forragem com maior teor de PB e menor de FDN na entrada e saída dos animais da pastagem.The oats (Avena strigosa Schreb. and ryegrass (Lolium multiflorum Lam. sodseeding in pasture of coastcross (Cynodon dactylon (L. Pers. was compared to oats and ryegrass in extreme tillage, as establishment methods of winter pastures under rotational stocking with lactating Holstein dairy cows. The total DM production (DMP, pre-grazed herbage mass, residue (RES, forage losses (FL, daily DM accumulation rate (DAR, stocking rate (SR, forage on offer (FO and leaf blade biomass (LBB were evaluated. For botanical composition, oats, ryegrass and coastcross were separated in the structural components: leaves, stems and dead material. Hand plucking samples for CP and NDF determinations were collected during pre- and post-grazing. The DMP, HM, RES, FL, DAR, SR and FO were not

  18. Imaging mass spectrometer with mass tags

    Science.gov (United States)

    Felton, James S.; Wu, Kuang Jen J.; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2013-01-29

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  19. Alienation, Mass Society and Mass Culture.

    Science.gov (United States)

    Dam, Hari N.

    This monograph examines the nature of alienation in mass society and mass culture. Conceptually based on the "Gemeinschaft-Gesellschaft" paradigm of sociologist Ferdinand Tonnies, discussion traces the concept of alienation as it appears in the philosophies of Hegel, Marx, Kierkegaard, Sartre, and others. Dwight Macdonald's "A Theory of Mass…

  20. Grazing management strategies for massaigrass-forage peanut pastures: 1. dynamics of sward condition and botanical composition Estratégias de manejo do pastejo para pastos consorciados de capim-massai e amendoim forrageiro: 1. dinâmica da condição do pasto e da composição botânica

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2006-04-01

    Full Text Available This study was carried out from October 2002 to December 2003 to evaluate the dynamics of sward condition and botanical composition of a mixed massaigrass (Panicum maximum x P. infestum, cv. Massai and forage peanut (Arachis pintoi Ac 01 pasture, intermittently stocked at three daily herbage allowance levels (9.0, 14.5 and 18.4% live weight. Sward condition was characterized in each grazing cycle in terms of the pre and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, legume and weeds was evaluated before each grazing period. Sward height and forage mass increased linearly with increasing herbage allowance (HA levels, and higher values were observed during the rainy season. Percentage of bare ground increased primarily at the lowest HA level. Percentage of forage peanut increased throughout the experimental period, primarily in the barest and shortest swards, under the lowest HA level. In the last quarter of 2003 the legume constituted 23.5, 10.6 and 6.4% of the pasture forage mass, respectively, from the lowest to the highest HA level. These results suggest that forage peanut can be successfully associated with massaigrass, as long as the pre-grazing sward height is maintained shorter than 65-70 cm, which will prevent excessive shading to the legume.Este estudo foi realizado com o objetivo de avaliar a dinâmica e a composição botânica de uma pastagem consorciada de capim-massai (Panicum maximum x P. infestum, cv. Massai e amendoim forrageiro (Arachis pintoi Ac 01, manejada sob lotação rotacionada em três níveis de oferta diária de forragem (9,0; 14,5 e 18,4% do peso vivo. A condição da pastagem foi caracterizada em cada ciclo de pastejo, em termos de altura, massa de forragem e porcentagem de solo descoberto (pré e pós-pastejo. A composição botânica da pastagem (gramínea, leguminosa e invasoras foi monitorada antes de cada período de ocupação. Houve aumento linear da altura

  1. Mass Customization Measurements Metrics

    DEFF Research Database (Denmark)

    Nielsen, Kjeld; Brunø, Thomas Ditlev; Jørgensen, Kaj Asbjørn

    2014-01-01

    A recent survey has indicated that 17 % of companies have ceased mass customizing less than 1 year after initiating the effort. This paper presents measurement for a company’s mass customization performance, utilizing metrics within the three fundamental capabilities: robust process design, choice...... navigation, and solution space development. A mass customizer when assessing performance with these metrics can identify within which areas improvement would increase competitiveness the most and enable more efficient transition to mass customization....

  2. Baryon masses with dynamical twisted mass fermions

    CERN Document Server

    Alexandrou, C; Koutsou, G; Baron, R; Guichon, P; Brinet, M; Carbonell, J; Drach, V; Liu, Z; Pène, O; Urbach, C

    2007-01-01

    We present results on the mass of the nucleon and the $\\Delta$ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of 690-300 MeV on lattices of size 2.1 fm and 2.7 fm. We check for cutoff effects by evaluating these baryon masses on lattices of spatial size 2.1 fm with lattice spacings $a(\\beta=3.9)=0.0855(6)$ fm and $a(\\beta=4.05)=0.0666(6)$ fm, determined from the pion sector and find them to be within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. The nucleon mass at the physical point provides a determination of the lattice spacing. Using heavy baryon chiral perturbation theory at ${\\cal O}(p^3)$ we find $a(\\beta=3.9)=0.0879(12)$ fm, with a systematic error due to the chiral extrapolation estimated to be about the same as the statistical error. This value of the lattice spacing is in good agreement with the value determined from the pion se...

  3. On Defining Mass

    Science.gov (United States)

    Hecht, Eugene

    2011-01-01

    Though central to any pedagogical development of physics, the concept of mass is still not well understood. Properly defining mass has proven to be far more daunting than contemporary textbooks would have us believe. And yet today the origin of mass is one of the most aggressively pursued areas of research in all of physics. Much of the excitement…

  4. Pangloss: Reconstructing lensing mass

    Science.gov (United States)

    Collett, Thomas E.; Marshall, Philip J.; Mason, Charlotte

    2015-11-01

    Pangloss reconstructs all the mass within a light cone through the Universe. Understanding complex mass distributions like this is important for accurate time delay lens cosmography, and also for accurate lens magnification estimation. It aspires to use all available data in an attempt to make the best of all mass maps.

  5. The Cosmological Mass Function

    CERN Document Server

    Monaco, P

    1997-01-01

    This thesis aims to review the cosmological mass function problem, both from the theoretical and the observational point of view, and to present a new mass function theory, based on realistic approximations for the dynamics of gravitational collapse. Chapter 1 gives a general introduction on gravitational dynamics in cosmological models. Chapter 2 gives a complete review of the mass function theory. Chapters 3 and 4 present the ``dynamical'' mass function theory, based on truncated Lagrangian dynamics and on the excursion set approach. Chapter 5 reviews the observational state-of-the-art and the main applications of the mass function theories described before. Finally, Chapter 6 gives conclusions and future prospects.

  6. Miniaturised TOF mass spectrometer

    Science.gov (United States)

    Rohner, U.; Wurz, P.; Whitby, J.

    2003-04-01

    For the BepiColombo misson of ESA to Mercury, we built a prototype of a miniaturised Time of Flight mass spectrometer with a low mass and low power consumption. Particles will be set free form the surface and ionized by short laser pluses. The mass spectrometer is dedicated to measure the elemental and isotopic composition of almost all elements of Mercurys planetary surface with an adequate dynamique range, mass range and mass resolution. We will present first results of our prototype and future designs.

  7. The Meson Mass System

    CERN Document Server

    Palazzi, Paolo

    2007-01-01

    The neglected 35 MeV/c2 particle mass quantization hypothesis has recently been reassessed for all known meson states. The rule is found to be statistically relevant, once the states are grouped by quark composition and JPC, with slightly different mass units for each group. In certain groups the mass unit is spin-dependent. Also the mass units are linearly quantized, with highly structured correlation patterns. The baryon masses are organized along similar lines. These results support an indication that hadrons might be shell-structured.

  8. Origins of Mass

    CERN Document Server

    Wilczek, Frank

    2012-01-01

    Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. Most of the mass of standard matter, by far, arises dynamically, from back-reaction of the color gluon fields of quantum chromodynamics (QCD). The equations for massless particles support extra symmetries - specifically scale, chiral, and gauge symmetries. The consistency of the standard model relies on a high degree of underlying gauge and chiral symmetry, so the observed non-zero masses of many elementary particles ($W$ and $Z$ bosons, quarks, and leptons) requires spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous symmetry breaking and for mass-generation, since photons acquire mass inside superconductors. A conceptually similar but more intricate form of all-pervasive (i.e. cosmic) superconductivity, in the context of the electroweak standard model, gives us a successful, economical account of $W$ and $Z$ boson masses. It also al...

  9. The Point Mass Concept

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2011-04-01

    Full Text Available A point-mass concept has been elaborated from the equations of the gravitational field. One application of these deductions results in a black hole configuration of the Schwarzschild type, having no electric charge and no angular momentum. The critical mass of a gravitational collapse with respect to the nuclear binding energy is found to be in the range of 0.4 to 90 solar masses. A second application is connected with the spec- ulation about an extended symmetric law of gravitation, based on the options of positive and negative mass for a particle at given positive energy. This would make masses of equal polarity attract each other, while masses of opposite polarity repel each other. Matter and antimatter are further proposed to be associated with the states of positive and negative mass. Under fully symmetric conditions this could provide a mechanism for the separation of antimatter from matter at an early stage of the universe.

  10. Fourier transform mass spectrometry.

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-07-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook.

  11. Mercury's Protoplanetary Mass

    CERN Document Server

    Herndon, J M

    2004-01-01

    Major element fractionation among chondrites has been discussed for decades as ratios relative to Si or Mg. Recently, by expressing ratios relative to Fe, I discovered a new relationship admitting the possibility that ordinary chondrite meteorites are derived from two components, a relatively oxidized and undifferentiated, primitive component and a somewhat differentiated, planetary component, with oxidation state like the highly reduced enstatite chondrites, which I suggested was identical to Mercury's complement of lost elements. Here, on the basis of that relationship, I derive expressions, as a function of the mass of planet Mercury and the mass of its core, to estimate the mass of Mercury's lost elements, the mass of Mercury's alloy and rock protoplanetary core, and the mass of Mercury's gaseous protoplanet. Although Mercury's mass is well known, its core mass is not, being widely believed to be in the range of 70-80 percent of the planet mass. For a core mass of 75 percent, the mass of Mercury's lost el...

  12. Is Mass Customization Sustainable?

    DEFF Research Database (Denmark)

    Petersen, Thomas Ditlev; Jørgensen, Kaj Asbjørn; Nielsen, Kjeld

    2011-01-01

    Mass customizers are like other companies currently experiencing an increasing customer demand for environmentally sustainable products as well as an increasingly strict legislation regarding environmental sustainability. This paper addresses the issue whether the concepts mass customization...... and sustainability are fundamentally compatible by asking the question: can a mass customized product be sustainable? Several factors could indicate that mass customized products are less sustainable than standardized products; however other factors suggest the opposite. This paper explores these factors during...... three life cycle phases for a product: Production, Use and End of Life. It is concluded that there is not an unambiguous causal relationship between mass customization and sustainability; however several factors unique to mass customized products are essential to consider during product and process...

  13. MassAI

    DEFF Research Database (Denmark)

    2011-01-01

    A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX.......A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX....

  14. Does Information Have Mass?

    CERN Document Server

    Kish, Laszlo B

    2013-01-01

    Does information have mass? This question has been asked many times and there are many answers even on the Internet, including on Yahoo Answers. Usually the answer is "no". Attempts have been made to assess the physical mass of information by estimating the mass of electrons feeding the power-guzzling computers and devices making up the Internet, the result being around 50 gram. Other efforts to calculate the mass of information have assumed that each electron involved in signal transfer carries one bit of information, which makes the corresponding mass to be about 10^-5 gram. We address the fundamental question of minimum mass related to a bit of information from the angles of quantum physics and special relativity. Our results indicate that there are different answers depending on the physical situation, and sometimes the mass can even be negative. We tend to be skeptical about the earlier mass estimations, mentioned above, because our results indicate that the electron's mass does not play a role in any on...

  15. MassAI

    DEFF Research Database (Denmark)

    2011-01-01

    A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX.......A software tool for general analysis and data-mining of mass-spectrometric datasets. The program features a strong emphasis on scan-by-scan identification and results-transparency. MassAI also accommodates residue level analysis of labelled runs, e.g. HDX....

  16. Digital Imaging Mass Spectrometry

    CERN Document Server

    Bamberger, Casimir; Bamberger, Andreas

    2011-01-01

    Methods to visualize the two-dimensional distribution of molecules by mass spectrometric imaging evolve rapidly and yield novel applications in biology, medicine, and material surface sciences. Most mass spectrometric imagers acquire high mass resolution spectra spot-by-spot and thereby scan the object's surface. Thus, imaging is slow and image reconstruction remains cumbersome. Here we describe an imaging mass spectrometer that exploits the true imaging capabilities by ion optical means for the time of flight mass separation. The mass spectrometer is equipped with the ASIC Timepix chip as an array detector to acquire the position, mass, and intensity of ions that are imaged by MALDI directly from the target sample onto the detector. This imaging mass spectrometer has a spatial resolving power at the specimen of (84\\pm35) \\mu m with a mass resolution of 45 and locates atoms or organic compounds on a surface area up to ~2 cm2. Extended laser spots of ~5 mm2 on structured specimens allowed parallel imaging of s...

  17. Absolute neutrino mass update

    CERN Document Server

    Päs, H; P\\"as, Heinrich; Weiler, Thomas J.

    2002-01-01

    The determination of absolute neutrino masses is crucial for the understanding of theories underlying the standard model, such as SUSY. We review the experimental prospects to determine absolute neutrino masses and the correlations among approaches, using the Delta m^2's inferred from neutrino oscillation experiments and assuming a three neutrino Universe.

  18. ABSOLUTE NEUTRINO MASSES

    DEFF Research Database (Denmark)

    Schechter, J.; Shahid, M. N.

    2012-01-01

    We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos.......We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos....

  19. Photon mass from inflation.

    Science.gov (United States)

    Prokopec, Tomislav; Törnkvist, Ola; Woodard, Richard

    2002-09-01

    We consider vacuum polarization from massless scalar electrodynamics in de Sitter inflation. The theory exhibits a 3+1 dimensional analog of the Schwinger mechanism in which a photon mass is dynamically generated. The mechanism is generic for light scalar fields that couple minimally to gravity. The nonvanishing of the photon mass during inflation may result in magnetic fields on cosmological scales.

  20. Mass preserving image registration

    DEFF Research Database (Denmark)

    Gorbunova, Vladlena; Sporring, Jon; Lo, Pechin Chien Pau

    2010-01-01

    The paper presents results the mass preserving image registration method in the Evaluation of Methods for Pulmonary Image Registration 2010 (EMPIRE10) Challenge. The mass preserving image registration algorithm was applied to the 20 image pairs. Registration was evaluated using four different...

  1. Top Quark Mass

    CERN Document Server

    Mulders, Martijn

    2016-01-01

    Ever since the discovery of the top quark at the Tevatron collider in 1995 the measurement of its mass has been a high priority. As one of the fundamental parameters of the Standard Theory of particle physics, the precise value of the top quark mass together with other inputs provides a test for the self-consistency of the theory, and has consequences for the stability of the Higgs field that permeates the Universe. In this review I will briefly summarize the experimental techniques used at the Tevatron and the LHC experiments throughout the years to measure the top quark mass with ever improving accuracy, and highlight the recent progress in combining all measurements in a single world average combination. As experimental measurements became more precise, the question of their theoretical interpretation has become important. The difficulty of relating the measured quantity to the fundamental top mass parameter has inspired alternative measurement methods that extract the top mass in complementary ways. I wil...

  2. Deconstructed Transverse Mass Variables

    CERN Document Server

    Ismail, Ahmed; Virzi, Joseph S; Walker, Devin G E

    2014-01-01

    Traditional searches for R-parity conserving natural supersymmetry (SUSY) require large transverse mass and missing energy cuts to separate the signal from large backgrounds. SUSY models with compressed spectra inherently produce signal events with small amounts of missing energy that are hard to explore. We use this difficulty to motivate the construction of "deconstructed" transverse mass variables which are designed preserve information on both the norm and direction of the missing momentum. We demonstrate the effectiveness of these variables in searches for the pair production of supersymmetric top-quark partners which subsequently decay into a final state with an isolated lepton, jets and missing energy. We show that the use of deconstructed transverse mass variables extends the accessible compressed spectra parameter space beyond the region probed by traditional methods. The parameter space can further be expanded to neutralino masses that are larger than the difference between the stop and top masses. ...

  3. Miniature mass analyzer

    CERN Document Server

    Cuna, C; Lupsa, N; Cuna, S; Tuzson, B

    2003-01-01

    The paper presents the concept of different mass analyzers that were specifically designed as small dimension instruments able to detect with great sensitivity and accuracy the main environmental pollutants. The mass spectrometers are very suited instrument for chemical and isotopic analysis, needed in environmental surveillance. Usually, this is done by sampling the soil, air or water followed by laboratory analysis. To avoid drawbacks caused by sample alteration during the sampling process and transport, the 'in situ' analysis is preferred. Theoretically, any type of mass analyzer can be miniaturized, but some are more appropriate than others. Quadrupole mass filter and trap, magnetic sector, time-of-flight and ion cyclotron mass analyzers can be successfully shrunk, for each of them some performances being sacrificed but we must know which parameters are necessary to be kept unchanged. To satisfy the miniaturization criteria of the analyzer, it is necessary to use asymmetrical geometries, with ion beam obl...

  4. Mass Defect from Nuclear Physics to Mass Spectral Analysis

    Science.gov (United States)

    Pourshahian, Soheil

    2017-09-01

    Mass defect is associated with the binding energy of the nucleus. It is a fundamental property of the nucleus and the principle behind nuclear energy. Mass defect has also entered into the mass spectrometry terminology with the availability of high resolution mass spectrometry and has found application in mass spectral analysis. In this application, isobaric masses are differentiated and identified by their mass defect. What is the relationship between nuclear mass defect and mass defect used in mass spectral analysis, and are they the same? [Figure not available: see fulltext.

  5. Top quark mass measurement

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Tuula [Univ. of Helsinki (Finland)

    2008-03-18

    The top quark is the heaviest elementary particle. Its mass is one of the fundamental parameters of the standard model of particle physics, and an important input to precision electroweak tests. This thesis describes three measurements of the top-quark mass in the dilepton decay channel. The dilepton events have two neutrinos in the final state; neutrinos are weakly interacting particles that cannot be detected with a multipurpose experiment. Therefore, the signal of dilepton events consists of a large amount of missing energy and momentum carried off by the neutrinos. The top-quark mass is reconstructed for each event by assuming an additional constraint from a top mass independent distribution. Template distributions are constructed from simulated samples of signal and background events, and parametrized to form continuous probability density functions. The final top-quark mass is derived using a likelihood fit to compare the reconstructed top mass distribution from data to the parametrized templates. One of the analyses uses a novel technique to add top mass information from the observed number of events by including a cross-section-constraint in the likelihood function. All measurements use data samples collected by the CDF II detector.

  6. Supersymmetry for Fermion Masses

    Institute of Scientific and Technical Information of China (English)

    LIU Chun

    2007-01-01

    It is proposed that supersymmetry (SUSY) may be used to understand fermion mass hierarchies. A family symmetry Z3L is introduced, which is the cyclic symmetry among the three generation SU(2) doublets. SUSY breaks at a high energy scale ~ 1011 GeV. The electroweak energy scale ~ 100 GeV is unnaturally small. No additional global symmetry, like the R-parity, is imposed. The Yukawa couplings and R-parity violating couplings all take their natural values, which are (&)(100 ~ 10-2). Under the family symmetry, only the third generation charged fermions get their masses. This family symmetry is broken in the soft SUSY breaking terms, which result in a hierarchical pattern of the fermion masses. It turns out that for the charged leptons, the τ mass is fromthe Higgs vacuum expectation value (VEV)and the sneutrino VEVs, the muon mass is due to the sneutrino VEVs, and the electron gains its mass due to both Z3L and SUSY breaking. The large neutrino mixing are produced with neutralinos playing the partial role of right-handed neutrinos. |Ve3|, which is for ve-vτ mixing, is expected to be about 0.1. For the quarks, the third generation masses are from the Higgs VEVs, the second generation masses are from quantum corrections, and the down quark mass due to the sneutrino VEVs. It explains mc/ms, ms/me, md > mu, and so on. Other aspects of the model are discussed.

  7. [Atypical intraperitoneal cystic masses].

    Science.gov (United States)

    Domínguez-Pérez, S T; Baeza-Herrera, C; Villalobos-Castillejos, A; González-Mateos, T; Aguilar-Venegas, M

    2010-01-01

    Omental, mesenteric and retroperitoneal cystic masses are very rare in pediatric population. They usually present as asymptomatic abdominal tumors and only occasionally a preoperative diagnosis is made. We presented 4 cases presented to our hospital during a 2-year period. All patients were male with an age ranged from 5 months to 7 years. Three patients had previous diagnosis of cystic mass by abdominal ultrasound. Three patients presented with acute abdomen and one patient with bowel obstruction. All patients underwent successful resection of the mass with no perioperative mortality.

  8. Graviton Mass Bounds

    CERN Document Server

    de Rham, Claudia; Tolley, Andrew J; Zhou, Shuang-Yong

    2016-01-01

    Recently, aLIGO has announced the first direct detections of gravitational waves, a direct manifestation of the propagating degrees of freedom of gravity. The detected signals GW150914 and GW151226 have been used to examine the basic properties of these gravitational degrees of freedom, particularly setting an upper bound on their mass. It is timely to review what the mass of these gravitational degrees of freedom means from the theoretical point of view, particularly taking into account the recent developments in constructing consistent massive gravity theories. Apart from the GW150914 mass bound, a few other observational bounds have been established from the effects of the Yukawa potential, modified dispersion relation and fifth force that are all induced when the fundamental gravitational degrees of freedom are massive. We review these different mass bounds and examine how they stand in the wake of recent theoretical developments and how they compare to the bound from GW150914.

  9. Mass Separation by Metamaterials.

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-25

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  10. Improved Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Improved Mass Spectrometer project will develop system requirements and analyze the path to space qualification.   The results of this project...

  11. W mass measurement

    CERN Document Server

    Andari, Nansi; The ATLAS collaboration

    2017-01-01

    A first measurement of the W-boson mass at the LHC is presented based on about 4.6 fb^-1 of proton–proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector. The measured value is 80370±19 MeV, consistent with the Standard Model prediction, with the combined values measured at the LEP and Tevatron colliders, and with the world average. The ATLAS result equals in precision the previous best measurement of the W mass, performed by the CDF collaboration. The CMS results for the W-like measurement of the Z boson mass using dimuon events are also shown. An overview of the analyses is shown with a special emphasis on the evaluation of the experimental systematic uncertainties, as well as on the uncertainties due to the modelling of the vector boson production and decay.

  12. Absolute Neutrino Mass Determination

    CERN Document Server

    Päs, H

    2001-01-01

    We discuss four approaches to the determination of absolute neutrino mass. These are the measurement of the zero-neutrino double beta decay rate, of the tritium decay end-point spectrum, of the cosmic ray spectrum above the GZK cutoff, and the cosmological measurement of the power spectrum governing the CMB and large scale structure. The first two approaches are sensitive to the mass eigenstates coupling to the electron neutrino, whereas the latter two are sensitive to the heavy component of the cosmic neutrino background. All mass eigenstates are related by the $\\Delta m^2$'s inferred from neutrino oscillation data. Consequently, the potential for absolute mass determination of each of the four approaches is correlated with the other three, in ways that we point out.

  13. Paperbacks in Mass Communication

    Science.gov (United States)

    Hardt, Hanno

    1978-01-01

    Lists paperback books on mass communication, divided into six categories: history and biography; appraisals of the press, law, and ethics; cultural, psychological, and social aspects; radio, television, film, photography; international communication; and journalism techniques, miscellaneous. (GW)

  14. Arkitektur & Mass customization

    DEFF Research Database (Denmark)

    Ryborg Jørgensen, Thomas

    2007-01-01

    Publikationens ambition er at udrede og give indblik i produktindustriens seneste udvikling med forretnings- og produktionsstrategien Mass Customization, og dermed en indgang til de muligheder og problemer der knytter sig til implementering af disse eller tilsvarende strategier i byggebranchen, og...

  15. Stable lepton mass matrices

    CERN Document Server

    Domcke, Valerie

    2016-01-01

    We study natural lepton mass matrices, obtained assuming the stability of physical flavour observables with respect to the variations of individual matrix elements. We identify all four possible stable neutrino textures from algebraic conditions on their entries. Two of them turn out to be uniquely associated to specific neutrino mass patterns. We then concentrate on the semi-degenerate pattern, corresponding to an overall neutrino mass scale within the reach of future experiments. In this context we show that i) the neutrino and charged lepton mixings and mass matrices are largely constrained by the requirement of stability, ii) naturalness considerations give a mild preference for the Majorana phase most relevant for neutrinoless double-beta decay, $\\alpha \\sim \\pi/2$, and iii) SU(5) unification allows to extend the implications of stability to the down quark sector. The above considerations would benefit from an experimental determination of the PMNS ratio $|U_{32}/U_{31}|$, i.e. of the Dirac phase $\\delta...

  16. White Dwarf Mass Distribution

    CERN Document Server

    Kepler, S O; Romero, Alejandra Daniela; Ourique, Gustavo; Pelisoli, Ingrid

    2016-01-01

    We present the mass distribution for all S/N > 15 pure DA white dwarfs detected in the Sloan Digital Sky Survey up to Data Release 12, fitted with Koester models for ML2/alpha=0.8, and with Teff > 10 000 K, and for DBs with S/N >10, fitted with ML2/alpha=1.25, for Teff > 16 000 K. These mass distributions are for log g > 6.5 stars, i.e., excluding the Extremely Low Mass white dwarfs. We also present the mass distributions corrected by volume with the 1/Vmax approach, for stars brighter than g=19. Both distributions have a maximum at M=0.624 Msun but very distinct shapes. From the estimated z-distances, we deduce a disk scale height of 300 pc. We also present 10 probable halo white dwarfs, from their galactic U, V, W velocities.

  17. Cantilever Based Mass Sensing

    DEFF Research Database (Denmark)

    Dohn, Søren

    2007-01-01

    Cantilever based mass sensors utilize that a change in vibrating mass will cause a change in the resonant frequency. This can be used for very accurate sensing of adsorption and desorption processes on the cantilever surface. The change in resonant frequency caused by a single molecule depends...... on various parameters including the vibrating mass of the cantilever and the frequency at which it vibrates. The minimum amount of molecules detectable is highly dependent on the noise of the system as well as the method of readout. The aim of this Ph.D. thesis has been twofold: To develop a readout method...... suitable for a portable device and to investigate the possibility of enhancing the functionality and sensitivity of cantilever based mass sensors. A readout method based on the hard contact between the cantilever and a biased electrode placed in close proximity to the cantilever is proposed. The viability...

  18. Competitiveness in mass tourism

    OpenAIRE

    Claver Cortés, Enrique; Molina-Azorín, José F.; Pereira-Moliner, Jorge

    2007-01-01

    This paper offers an indepth analysis of a second-generation destination specializing in sun and sand mass tourism: Benidorm, Spain. Contrary to the view of many researchers, it is argued that such destinations need not inevitably decline and can in fact continue to be competitive. The persistence of this sun and sand mass tourism model is shown empirically through an analysis of its evolution and competitive situation. The paper offers suggestions about the strategies Benidorm hotels s...

  19. Masses of Formal Philosophy

    DEFF Research Database (Denmark)

    Masses of Formal Philosophy is an outgrowth of Formal Philosophy. That book gathered the responses of some of the most prominent formal philosophers to five relatively open and broad questions initiating a discussion of metaphilosophical themes and problems surrounding the use of formal methods...... in philosophy. Including contributions from a wide range of philosophers, Masses of Formal Philosophy contains important new responses to the original five questions....

  20. Top Quark Mass

    Science.gov (United States)

    Mulders, Martijn

    2016-10-01

    Ever since the discovery of the top quark at the Tevatron collider in 1995 the measurement of its mass has been a high priority. As one of the fundamental parameters of the Standard Theory of particle physics, the precise value of the top quark mass together with other inputs provides a test for the self-consistency of the theory, and has consequences for the stability of the Higgs field that permeates the Universe. In this review I will briefly summarize the experimental techniques used at the Tevatron and the LHC experiments throughout the years to measure the top quark mass with ever improving accuracy, and highlight the recent progress in combining all measurements in a single world average combination. As experimental measurements became more precise, the question of their theoretical interpretation has become important. The difficulty of relating the measured quantity to the fundamental top mass parameter has inspired alternative measurement methods that extract the top mass in complementary ways. I will discuss the status of those techniques and their results, and present a brief outlook of further improvements in the experimental determination of the top quark mass to be expected at the LHC and beyond.

  1. Substernal Thyroid Masses

    Directory of Open Access Journals (Sweden)

    Mohamed A.H. Regal

    2010-10-01

    Full Text Available A thyroid mass, most often a non toxic colloid goiter or occasionally an adenoma, is not an unusual finding below the level of the thoracic inlet.1 In 1992 Creswell and Wells estimated that these tumors comprise 5.8% of all mediastinal lesions.1 There is no standard definition for thyroid glands extending below the thoracic inlet, but such masses descend from their original cervical location for more than 2 or 3 cm below the thoracic inlet, and are not truly primary tumors of the mediastinum. They preserve the connection between the thoracic and cervical portion and receive their blood supply from the neck.2,3 In 1940, the seminal report of Wakeley and Mulvany divided intrathoracic thyroid masses into 3 types; (1”Small substernal extension” of a mainly cervical mass, (2 “Partial” intrathoracic, in which the major portion of the mass is situated within the thorax, and (3”Complete” in which all of the mass lies within the thoracic cavity.

  2. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  3. Direct neutrino mass measurements

    Science.gov (United States)

    Thümmler, T.

    2011-07-01

    The determination of the neutrino rest mass plays an important role at the intersections of cosmology, particle physics and astroparticle physics. This topic is currently being addressed by two complementary approaches in laboratory experiments. Neutrinoless double beta decay experiments probe whether neutrinos are Majorana particles and determine an effective neutrino mass value. Single beta decay experiments such as KATRIN and MARE investigate the spectral shape of β-decay electrons close to their kinematic endpoint in order to determine the neutrino rest mass with a model-independent method. Owing to neutrino flavour mixing, the neutrino mass parameter appears as an average of all neutrino mass eigenstates contributing to the electron neutrino. The KArlsruhe TRItium Neutrino experiment (KATRIN) is currently the experiment in the most advanced status of commissioning. Applying an ultra-luminous molecular windowless gaseous tritium source and an integrating high-resolution spectrometer of MAC-E filter type, it allows β-spectroscopy close to the T 2 end-point with unprecedented precision and will reach a sensitivity of 200 meV/ c 2 (90% C.L.) on the neutrino rest mass.

  4. A micromachined mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, G.; Siebert, P.; Mueller, J. [Technische Univ. Hamburg-Harburg, Hamburg (Germany). Dept. of Microsystemtechnology

    2001-07-01

    This paper presents the concept, the processing and the simulated and measured characteristics of a miniaturised mass spectrometer, with dimensions of approximately only a few cm{sup 3}. The mass spectrometer consists of three main parts to be manufactured by micro structuring: an electron source, an ionisation chamber including accelerating and focusing units and a mass analyser with detector. Its fabrication is based on techniques used in micro-system processing and in particular anisotropic etching, thin film deposition, electroplating, and anodic bonding. The aim of the concept for this micro mass spectrometer is not only to scale down a macroscopic system but it also takes advantage of the added features of a micro system, i.e. a high Knudsen number of about 3 at a pressure of a few Pascal, and high field strengths at a relatively low voltage. Therefore, the demands on the vacuum systems and the electrical circuits are much more simple compared to a macroscopic mass spectrometer. In the presented design of the micro mass spectrometer the resolution is in the range of 10 to 20 at a sensitivity of several tens of ppm. (orig.)

  5. Pediatric Neck Mass

    Directory of Open Access Journals (Sweden)

    Guilherme Machado de Carvalho

    2015-11-01

    Full Text Available Introduction  Neck masses include a wide variety of diagnostic possibilities, with more than 60 etiologies that depend on clinical aspects such as age, location and time of disease progression. The interview and physical examination guide research that cross the neck masses in pediatric patients in 3 groups: infectious / inflammatory, and neoplastic embryonic remnants. The aim of this study was to present a protocol for evaluation of neck masses in the pediatric age group, based on a review of literature on the subject and experience of this service. Materials and Methods Survey of literature data from PubMed / Medline, Google Scholar and Scopus Database without language restriction, since 1980 sources, with the MeSH term "Pediatric neck mass".  Results Prepared flowchart guidelines to be followed according with diagnostic suspicions. Patients were divided into 3 groups according to the initial clinical manifestations and according to etiological hypotheses formulated recommend evaluations protocols.  Conclusion The standardization of the evaluation of neck masses in children proves valuable and can help in the differential diagnosis of different etiologies involved.

  6. Fermion masses from dimensional reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kapetanakis, D. (National Research Centre for the Physical Sciences Democritos, Athens (Greece)); Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))

    1990-10-11

    We consider the fermion masses in gauge theories obtained from ten dimensions through dimensional reduction on coset spaces. We calculate the general fermion mass matrix and we apply the mass formula in illustrative examples. (orig.).

  7. Heat and mass transfer

    CERN Document Server

    Baehr, Hans Dieter

    2011-01-01

    This comprehensive textbook provides a solid foundation of knowledge on the principles of heat and mass transfer and shows how to solve problems by applying modern methods. The basic theory is developed systematically, exploring in detail the solution methods to all important problems.   The thoroughly revised 3rd edition includes an introduction to the numerical solution of Finite Elements. A new section on heat and mass transfer in porous media has also been added.   The book will be useful not only to upper-level and graduate students, but also to practicing scientists and engineers, offering a firm understanding of the principles of heat and mass transfer, and showing how to solve problems by applying modern methods. Many completed examples and numerous exercises with solutions facilitate learning and understanding, and an appendix includes data on key properties of important substances.

  8. Keaton and the Masses

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    This paper explores conflicts between individual and mass and the process of 'massification' (i.e. the becoming of masses) as comic potential in Buster Keaton’s physical comedies. This comic potential is characterized by a person’s formalized and aestheticized de-individualization when confronted...... with tangible, non-human matter. As already indicated by Henri Bergson, de-individualization plays an important role in modern comedy in general. With his intense focus on massification, Keaton is not only one of the first, but also one of the most dedicated investigators of comic de-individualization by purely...... and thematics of the films and down to the comic details of each individual gag. The paper initiates by considering the complex relations in Keaton between gag and narrative with specific regard to the conflict between the individual and the masses. This leads to an exploration of the basic compositional...

  9. Keaton and the Masses

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    This paper explores conflicts between individual and mass and the process of 'massification' (i.e. the becoming of masses) as comic potential in Buster Keaton’s physical comedies. This comic potential is characterized by a person’s formalized and aestheticized de-individualization when confronted...... with tangible, non-human matter. As already indicated by Henri Bergson, de-individualization plays an important role in modern comedy in general. With his intense focus on massification, Keaton is not only one of the first, but also one of the most dedicated investigators of comic de-individualization by purely...... and thematics of the films and down to the comic details of each individual gag. The paper initiates by considering the complex relations in Keaton between gag and narrative with specific regard to the conflict between the individual and the masses. This leads to an exploration of the basic compositional...

  10. Large area mass analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Rachev, Mikhail [Max-Planck-Institut for Nuclear Physics, Heidelberg Saupfercheckweg 1, Heidelberg 69117 (Germany)]. E-mail: mikhail.rachev@mpi-hd.mpg.de; Srama, Ralf [Max-Planck-Institut for Nuclear Physics, Heidelberg Saupfercheckweg 1, Heidelberg 69117 (Germany); Srowig, Andre [Max-Planck-Institut for Nuclear Physics, Heidelberg Saupfercheckweg 1, Heidelberg 69117 (Germany); Gruen, Eberhard [Max-Planck-Institut for Nuclear Physics, Heidelberg Saupfercheckweg 1, Heidelberg 69117 (Germany)

    2004-12-11

    A new time-of-flight spectrometer for the chemical analysis of cosmic dust particles in space has been simulated by Simion 7.0. The instrument is based upon impact ionization. This method is a reliable method for in situ dust detection and is well established. Instruments using the impact ionization flew on board of Helios and Galileo and are still in operation on board of the Ulysses and Cassini-Huygens missions. The new instrument has a large sensitive area of 0.1m2 in order to achieve a significant number of measurements. The mass resolution M/{delta}M>100 and the mass range covers the most relevant elements expected in cosmic dust. The instrument has a reflectron configuration which increases the mass resolution. Most of the ions released during the impact are focused to the detector. The ion detector consists of a large area ion-to-electron converter, an electron reflectron and a microchannel plate detector.

  11. Diffusion and mass transfer

    CERN Document Server

    Vrentas, James S

    2013-01-01

    The book first covers the five elements necessary to formulate and solve mass transfer problems, that is, conservation laws and field equations, boundary conditions, constitutive equations, parameters in constitutive equations, and mathematical methods that can be used to solve the partial differential equations commonly encountered in mass transfer problems. Jump balances, Green’s function solution methods, and the free-volume theory for the prediction of self-diffusion coefficients for polymer–solvent systems are among the topics covered. The authors then use those elements to analyze a wide variety of mass transfer problems, including bubble dissolution, polymer sorption and desorption, dispersion, impurity migration in plastic containers, and utilization of polymers in drug delivery. The text offers detailed solutions, along with some theoretical aspects, for numerous processes including viscoelastic diffusion, moving boundary problems, diffusion and reaction, membrane transport, wave behavior, sedime...

  12. Treatment of appendiceal mass

    DEFF Research Database (Denmark)

    Olsen, Jesper; Skovdal, Jan; Qvist, Niels;

    2014-01-01

    INTRODUCTION: The treatment strategy for appendiceal mass is controversial, ranging from operation or image-guided drainage to conservative treatment with or without antibiotics. The aim of this study was to assess the various treatment modalities with respect to complications and treatment failure...... in total 3,772 patients. Operation for appendiceal mass was beset with a moderate to high risk of complications of up to 57% and a risk of intestinal resection of up to 25%. Major complications were observed in up to 18% of cases. Conservative treatment with or without antibiotics was associated...... with a treatment failure rate of 8-15%. Drainage was beset with a risk of complications of 2-15% and a risk of treatment failure of 2-13%. CONCLUSION: Operation with appendectomy for appendiceal mass carries a high risk of complications compared with conservative treatment or drainage. Drainage may lower the risk...

  13. Bioreactor Mass Transport Studies

    Science.gov (United States)

    Kleis, Stanley J.; Begley, Cynthia M.

    1997-01-01

    The objectives of the proposed research efforts were to develop both a simulation tool and a series of experiments to provide a quantitative assessment of mass transport in the NASA rotating wall perfused vessel (RWPV) bioreactor to be flown on EDU#2. This effort consisted of a literature review of bioreactor mass transport studies, the extension of an existing scalar transport computer simulation to include production and utilization of the scalar, and the evaluation of experimental techniques for determining mass transport in these vessels. Since mass transport at the cell surface is determined primarily by the relative motion of the cell assemblage and the surrounding fluid, a detailed assessment of the relative motion was conducted. Results of the simulations of the motion of spheres in the RWPV under microgravity conditions are compared with flight data from EDU#1 flown on STS-70. The mass transport across the cell membrane depends upon the environment, the cell type, and the biological state of the cell. Results from a literature review of cell requirements of several scalars are presented. As a first approximation, a model with a uniform spatial distribution of utilization or production was developed and results from these simulations are presented. There were two candidate processes considered for the experimental mass transport evaluations. The first was to measure the dissolution rate of solid or gel beads. The second was to measure the induced fluorescence of beads as a stimulant (for example hydrogen peroxide) is infused into the vessel. Either technique would use video taped images of the process for recording the quantitative results. Results of preliminary tests of these techniques are discussed.

  14. Mass spectrometers: instrumentation

    Science.gov (United States)

    Cooks, R. G.; Hoke, S. H., II; Morand, K. L.; Lammert, S. A.

    1992-09-01

    Developments in mass spectrometry instrumentation over the past three years are reviewed. The subject is characterized by an enormous diversity of designs, a high degree of competition between different laboratories working with either different or similar techniques and by extremely rapid progress in improving analytical performance. Instruments can be grouped into genealogical charts based on their physical and conceptual interrelationships. This is illustrated using mass analyzers of different types. The time course of development of particular instrumental concepts is illustrated in terms of the s-curves typical of cell growth. Examples are given of instruments which are at the exponential, linear and mature growth stages. The prime examples used are respectively: (i) hybrid instruments designed to study reactive collisions of ions with surfaces: (ii) the Paul ion trap; and (iii) the triple quadrupole mass spectrometer. In the area of ion/surface collisions, reactive collisions such as hydrogen radical abstraction from the surface by the impinging ion are studied. They are shown to depend upon the chemical nature of the surface through the use of experiments which utilize self-assembled monolayers as surfaces. The internal energy deposited during surface-induced dissociation upon collision with different surfaces in a BEEQ instrument is also discussed. Attention is also given to a second area of emerging instrumentation, namely technology which allows mass spectrometers to be used for on-line monitoring of fluid streams. A summary of recent improvements in the performance of the rapidly developing quadrupole ion trap instrument illustrates this stage of instrument development. Improvements in resolution and mass range and their application to the characterization of biomolecules are described. The interaction of theory with experiment is illustrated through the role of simulations of ion motion in the ion trap. It is emphasized that mature instruments play a

  15. Spontaneously broken mass

    CERN Document Server

    Endlich, Solomon; Penco, Riccardo

    2013-01-01

    The Galilei group involves mass as a central charge. We show that the associated superselection rule is incompatible with the observed phenomenology of superfluid helium 4: this is recovered only under the assumption that mass is spontaneously broken. This remark is somewhat immaterial for the real world, where the correct space-time symmetries are encoded by the Poincar\\'e group, which has no central charge. Yet it provides an explicit example of how superselection rules can be experimentally tested. We elaborate on what conditions must be met for our ideas to be generalizable to the relativistic case of the integer/half-integer angular momentum superselection rule.

  16. A large thumb mass.

    Science.gov (United States)

    Shah, Amit K; Macnair, Rory; Figus, Andrea

    2012-02-01

    A 31-year-old man presented with a 5-year history of a spontaneously occurring soft tissue mass on the palmar aspect of his left non dominant thumb. Over 5 months he was having progressive difficulty flexing at the interphalangeal joint. Magnetic resonance imaging demonstrated an heterogeneously enhancing soft tissue mass likely to be either a peripheral fibromatosis or giant cell tumour of the flexor tendon (Figure 1). Intraoperatively a large neuroma in continuity with the ulnar digital nerve was found and debulked (Figure 2). The diagnosis was confirmed histologically.

  17. Light Quark Mass Effects in Bottom Quark Mass Determinations

    OpenAIRE

    Hoang, A. H.

    2001-01-01

    Recent results for charm quark mass effects in perturbative bottom quark mass determinations from $\\Upsilon$ mesons are reviewed. The connection between the behavior of light quark mass corrections and the infrared sensitivity of some bottom quark mass definitions is examined in some detail.

  18. Ion Mass Determination

    DEFF Research Database (Denmark)

    2010-01-01

    An apparatus (100) is described for determining the mass of ions, the apparatus configured to hold a plasma (101 ) having a plasma potential. The apparatus (100) comprises an electrode (102) having a surface extending in a surface plane and an insulator (104) interfacing with the electrode (102...

  19. The Origin of Mass

    CERN Document Server

    Raya, Alfredo

    2009-01-01

    Dynamical chiral symmetry breaking and confinement are two crucial features of Quantum Chromodynamics responsible for the nature of the hadron spectrum. These phenomena, presumably coincidental, can account for 98% of the mass of our visible universe. In this set of lectures, I shall present an introductory review of them in the light of the Schwinger-Dyson equations.

  20. Mass Equivalent Dyads

    NARCIS (Netherlands)

    van der Wijk, V.; Bai, Shaoping; Ceccarelli, Marco

    2015-01-01

    In this paper it is shown how a general 2-DoF dyad can be designed mass equivalent to a general (1-DoF) link element. This is useful in the synthesis of balanced mechanisms, for instance to increase or reduce the number of DoFs of a balanced mechanism maintaining its balance. Also it can be used as

  1. Mass equivalent triads

    NARCIS (Netherlands)

    van der Wijk, V.

    2015-01-01

    In this paper it is shown how a general 3-DoF triad can be designed mass equivalent to a general (1-DoF) link element. This is useful in the synthesis of shaking force balanced and statically balanced mechanisms, for instance to add or remove a number of DoFs of a balanced mechanism maintaining its

  2. Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    le Gac, S.; le Gac, Severine; van den Berg, Albert; van den Berg, A.; Unknown, [Unknown

    2009-01-01

    With this book we want to illustrate how two quickly growing fields of instrumentation and technology, both applied to life sciences, mass spectrometry and microfluidics (or microfabrication) naturally came to meet at the end of the last century and how this marriage impacts on several types of appl

  3. Mass Media and Society.

    Science.gov (United States)

    Wells, Alan

    Designed to serve as a basic text for general liberal arts courses in mass communication, this book presents essays, largely from recent magazine articles, written from the layman (although there are a few more overtly scholarly articles). It begins with an examination of the media industries in the United States, treating them as complex…

  4. Processes of Mass Communication.

    Science.gov (United States)

    Channey, David

    This sociological treatment of mass communications analysis first discusses the theories of audience behavior, then turns to the organization of media production, and closes with a study of performance. The book covers audience needs and gratifications, the history of British press and broadcasting results of systems of media distribution, the…

  5. Media, Minds, and Masses.

    Science.gov (United States)

    Baggot, James; Vino, Faith

    This booklet describes the language arts course "Media, Minds, and Masses," written for the Dade County, Fla., public schools. Topics for the course include the workings of contemporary radio, television, newspapers, magazines, and movies; the present status and power of media; the history and development of media; and the influences of…

  6. A female mass murder.

    Science.gov (United States)

    Katsavdakis, Kostas A; Meloy, J Reid; White, Stephen G

    2011-05-01

    A case study of a 44-year-old woman who committed a mass murder is presented. Following a chronic course of psychotic deterioration, and a likely diagnosis of paranoid schizophrenia that remained untreated, she returned to her workplace after 3 years from her termination and killed seven people and herself. Her history is reconstructed through investigation of primary and secondary source materials. Although there are very few female mass murderers in recorded criminal history, this case is quite similar to the known research on mass murderers in general. Such individuals often have a psychotic disorder evident in violent and paranoid delusions, show a deteriorating life course before the mass murder, intentionally plan and prepare for their assault, and methodically kill as many individuals as possible before taking their own lives. They typically do not directly threaten the target beforehand, but do leak their intent to third parties--however, in this case, leakage and other obvious warning behaviors did not occur. Such acts are impossible to predict but depend on threat management and target security for risk mitigation. © 2011 American Academy of Forensic Sciences.

  7. Neutrino Masses and Oscillations

    CERN Document Server

    Valle, J W F

    2005-01-01

    I summarize the status of three--neutrino oscillations that follow from combining the relevant world's data. The discussion includes the small parameters Delta_m-sol/Delta_m-atm and \\sin^2\\theta_{13}, which characterize the strength of CP violation in neutrino oscillations, the impact of oscillation data on the prospects for probing the absolute scale of neutrino mass in \

  8. "Magic" Ionization Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  9. Parametric Mass Reliability Study

    Science.gov (United States)

    Holt, James P.

    2014-01-01

    The International Space Station (ISS) systems are designed based upon having redundant systems with replaceable orbital replacement units (ORUs). These ORUs are designed to be swapped out fairly quickly, but some are very large, and some are made up of many components. When an ORU fails, it is replaced on orbit with a spare; the failed unit is sometimes returned to Earth to be serviced and re-launched. Such a system is not feasible for a 500+ day long-duration mission beyond low Earth orbit. The components that make up these ORUs have mixed reliabilities. Components that make up the most mass-such as computer housings, pump casings, and the silicon board of PCBs-typically are the most reliable. Meanwhile components that tend to fail the earliest-such as seals or gaskets-typically have a small mass. To better understand the problem, my project is to create a parametric model that relates both the mass of ORUs to reliability, as well as the mass of ORU subcomponents to reliability.

  10. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  11. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  12. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  13. Pondering Parotid Masses

    Directory of Open Access Journals (Sweden)

    Mark A Miller

    2001-01-01

    Full Text Available A49-year-old, human immunodeficiency virus (HIV- infected, Haitian-born woman presented with a left facial mass that she had noticed for the previous eight weeks. She was known to have been HIV-seropositive for the previous 11 years and had been on multiple antiretroviral therapies. Her past medical history was also significant for hypertension, disseminated varicella zoster virus and recurrent oral and buttock Herpes simplex episodes. She was taking the following medications at the time of her presentation with the facial mass: stavudine, lamivudine, didanosine, nelfinavir mesylate, famciclovir, hydrochlorothiazide and cotrimoxazole. She had no complaints of fever, chills, sweats, weight loss or anorexia. She denied any pain, redness or warmth at the site of the facial swelling. Her most recent CD4 lymphocyte count was 336 cells/µL, with an HIV viral load of log102.6 copies/mL. Physical examination revealed a 4 cm fluid-filled mass in the left parotid gland. There was no detectable induration, redness, warmth or tenderness, and no associated adenopathy. The rest of the examination was unremarkable. An aspirate of the mass was performed under sterile conditions and yielded 30 mL of turbid, yellow liquid. A Gram stain revealed no neutrophils, scant mononuclear cells and no visible organisms. An acid-fast stain was negative as well. Routine, mycobacterial and fungal cultures showed no growth. Cytological analysis showed scant reactive lymphocytes and no malignant cells. The patient was not given therapy and was observed for another two months. The fluid reaccumulated in the left parotid gland, and the patient?s only complaint concerned the unsightly appearance of the mass. The lesion was again aspirated for 30 mL of fluid and this time, the fluid had a turbid, brown appearance. All laboratory results were identical to the results from the first aspirate. What is your diagnosis, and how would you treat this patient?

  14. First mass measurement at JYFLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, A. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Eronen, T. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Hager, U. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Hakala, J. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Kolhinen, V. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Kopecky, S. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Rinta-Antila, S. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Szerypo, J. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland); Aeystoe, J. [Department of Physics, PB 35 (YFL), FIN-40014 University of Jyvaeskylae (Finland)

    2004-12-27

    The first mass measurements at JYFLTRAP facility are reviewed. Those are also first ever direct mass measurements of the heaviest Zr-isotopes. Results are compared to atomic mass evaluation data and the recent calculations. The first TOF-resonances from high-precision trap and an implication to high-precision mass measurements are discussed.

  15. Riddle of the Neutrino Mass

    CERN Document Server

    Smirnov, A Yu

    2015-01-01

    We discuss some known approaches and results as well as few new ideas concerning origins and nature of neutrino mass. The key issues include (i) connections of neutrino and charged fermions masses, relation between masses and mixing, energy scale of new physics behind neutrino mass where possibilities spread from the Planck and GUT masses down to a sub-eV scale. The data hint two different new physics involved in generation of neutrino mass. Determination of the CP phase as well as mass hierarchy can play important role in identification of new physics. It may happen that sterile neutrinos provide the key to resolve the riddle.

  16. The W Boson Mass Measurement

    Science.gov (United States)

    Kotwal, Ashutosh V.

    2016-10-01

    The measurement of the W boson mass has been growing in importance as its precision has improved, along with the precision of other electroweak observables and the top quark mass. Over the last decade, the measurement of the W boson mass has been led at hadron colliders. Combined with the precise measurement of the top quark mass at hadron colliders, the W boson mass helped to pin down the mass of the Standard Model Higgs boson through its induced radiative correction on the W boson mass. With the discovery of the Higgs boson and the measurement of its mass, the electroweak sector of the Standard Model is over-constrained. Increasing the precision of the W boson mass probes new physics at the TeV-scale. We summarize an extensive Tevatron (1984-2011) program to measure the W boson mass at the CDF and Dø experiments. We highlight the recent Tevatron measurements and prospects for the final Tevatron measurements.

  17. The W Boson Mass Measurement

    CERN Document Server

    Kotwal, Ashutosh V

    2016-01-01

    The measurement of the W boson mass has been growing in importance as its precision has improved, along with the precision of other electroweak observables and the top quark mass. Over the last decade, the measurement of the W boson mass has been led at hadron colliders. Combined with the precise measurement of the top quark mass at hadron colliders, the W boson mass helped to pin down the mass of the Standard Model Higgs boson through its induced radiative correction on the W boson mass. With the discovery of the Higgs boson and the measurement of its mass, the electroweak sector of the Standard Model is over-constrained. Increasing the precision of the W boson mass probes new physics at the TeV-scale. We summarize an extensive Tevatron (1984–2011) program to measure the W boson mass at the CDF and Dø experiments. We highlight the recent Tevatron measurements and prospects for the final Tevatron measurements.

  18. Masse et fascisme

    Directory of Open Access Journals (Sweden)

    Micha Brumlik

    2012-01-01

    Full Text Available L’époque du fascisme s’est annoncée comme une époque des masses, plus précisément des masses fascinées ou séduites par des chefs (Führer. Lorsque l’ouvrage majeur du sociologue Max Weber fut publié en 1921 à titre posthume, l’un de ses chapitres fut déjà consacré à la « domination charismatique » pour nommer, à travers le concept de « charisme », les qualités d’une personnalité « qui font qu’elle est perçue comme un chef, qui le font apparaître comme un émissaire de Dieu ou comme une personn...

  19. Nanoscale mass conveyors

    Science.gov (United States)

    Regan, Brian C.; Aloni, Shaul; Zettl, Alexander K.

    2008-03-11

    A mass transport method and device for individually delivering chargeable atoms or molecules from source particles is disclosed. It comprises a channel; at least one source particle of chargeable material fixed to the surface of the channel at a position along its length; a means of heating the channel; and a means for applying an controllable electric field along the channel, whereby the device transports the atoms or molecules along the channel in response to applied electric field. In a preferred embodiment, the mass transport device will comprise a multiwalled carbon nanotube (MWNT), although other one dimensional structures may also be used. The MWNT or other structure acts as a channel for individual or small collections of atoms due to the atomic smoothness of the material. Also preferred is a source particle of a metal such as indium. The particles move by dissociation into small units, in some cases, individual atoms. The particles are preferably less than 100 nm in size.

  20. Coronal Mass Ejections

    Science.gov (United States)

    Crooker, Nancy; Joselyn, Jo Ann; Feynman, Joan

    The early 1970's can be said to mark the beginning of The Enlightenment in the history of the Space Age, literally as well as by analogy to European history. Instruments blinded by Earth's atmosphere were lifted above and, for the first time, saw clearly and continuously the ethereal white light and sparkling x-rays from the solar corona. From these two bands of the light spectrum came images of coronal mass ejections and coronal holes, respectively. But whereas coronal holes were immediately identified as the source of high-speed solar wind streams, at first coronal mass ejections were greeted only by a sense of wonder. It took years of research to identify their signatures in the solar wind before the fastest ones could be identified with the well-known shock disturbances that cause the most violent space storms.

  1. Coronal Mass Ejections

    CERN Document Server

    Kunow, H; Linker, J. A; Schwenn, R; Steiger, R

    2006-01-01

    It is well known that the Sun gravitationally controls the orbits of planets and minor bodies. Much less known, however, is the domain of plasma fields and charged particles in which the Sun governs a heliosphere out to a distance of about 15 billion kilometers. What forces activates the Sun to maintain this power? Coronal Mass Ejections (CMEs) and their descendants are the troops serving the Sun during high solar activity periods. This volume offers a comprehensive and integrated overview of our present knowledge and understanding of Coronal Mass Ejections (CMEs) and their descendants, Interplanetary CMEs (ICMEs). It results from a series of workshops held between 2000 and 2004. An international team of about sixty experimenters involved e.g. in the SOHO, ULYSSES, VOYAGER, PIONEER, HELIOS, WIND, IMP, and ACE missions, ground observers, and theoreticians worked jointly on interpreting the observations and developing new models for CME initiations, development, and interplanetary propagation. The book provides...

  2. Neutrino Masses and Oscillations

    CERN Document Server

    CERN. Geneva. Audiovisual Unit; Treille, Daniel

    2002-01-01

    This course will not cover its subject in the customary way. The emphasis will be on the simple theoretical concepts (helicity, handedness, chirality, Majorana masses) which are obscure in most of the literature, and on the quantum mechanics of oscillations, that ALL books get wrong. Which, hopefully, will not deter me from discussing some of the most interesting results from the labs and from the cosmos.

  3. Masses of Fundamental Particles

    CERN Document Server

    Terazawa, Hidezumi

    2011-01-01

    Not only the masses of fundamental particles including the weak bosons, Higgs scalar, quarks, and leptons, but also the mixing angles of quarks and those of neutrinos are all explained and/or predicted in the unified composite model of quarks and leptons successfully. In addition, both of the two anomalies recently found by the CDF Collaboration are suggested to be taken as evidences for the substructure of the fundamental particles.

  4. Hydrogen Exchange Mass Spectrometry.

    Science.gov (United States)

    Mayne, Leland

    2016-01-01

    Hydrogen exchange (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.

  5. Chemical Ionization Mass Spectrometry.

    Science.gov (United States)

    1980-01-30

    mass spectrometer. Also discussed were Corporation, St. Louis , Mo. unique analytical applications of several negative ion chemical Synthesis of the...were purchsed from obtained at a probe temperature of 180-200 °C and displays Sigma Chemical Co.. St. Louis , Mo. Arginine hydrochloride (4) a M4...13) Rosenstock. H, M.: Drax . K.: Stener. B. W: Hernon J. T. J. Phys. Chem, Ref. Data 1977, 6, Supl. 1. 774-783,167 occur in the ratio of 10/ 1

  6. Neutrinos Mass and Mixing

    CERN Document Server

    González-Garciá, M Concepción

    1998-01-01

    I review the status of neutrino masses and mixings in the light of the solar and atmospheric neutrino data. The result from the LSND experiment and the possible role of neutrinos as hot dark matter are also included. I also discuss the simplest schemes proposed to reconcile these data which include a light sterile neutrino in addition to the three standard ones. Implications for future experiments are commented.

  7. Nonlinear pulsation masses

    Energy Technology Data Exchange (ETDEWEB)

    Davis, C.G.

    1990-01-01

    The advent of nonlinear pulsation theory really coincides with the development of the large computers after the second world war. Christy and Stobbie were the first to make use of finite difference techniques on computers to model the bumps'' observed in the classical Cepheid light and velocity curves, the so-called Hertzsprung'' sequence. Following this work a more sophisticated analysis of the light and velocity curves from the models was made by Simon and Davis using Fourier techniques. Recently a simpler amplitude equation formalism has been developed that helps explain this resonance mechanism. The determination of Population I Cepheid masses by nonlinear methods will be discussed. For the lower mass objects, such as RR Lyrae and BL Her. stars, we find general agreement using evolutionary masses and nonlinear pulsation theory. An apparent difficulty of nonlinear pulsation theory occurs in the understanding of double'' mode pulsation, which will also be discussed. Recent studies in nonlinear pulsation theory have dealt with the question of mode selection, period doubling and the trends towards chaotic behavior such as is observed in the transition from W Virginis to RV Tauri-like stars. 10 refs., 1 fig., 2 tabs.

  8. Mass extinction: a commentary

    Science.gov (United States)

    Raup, D. M.

    1987-01-01

    Four neocatastrophist claims about mass extinction are currently being debated; they are that: 1, the late Cretaceous mass extinction was caused by large body impact; 2, as many as five other major extinctions were caused by impact; 3, the timing of extinction events since the Permian is uniformly periodic; and 4, the ages of impact craters on Earth are also periodic and in phase with the extinctions. Although strongly interconnected the four claims are independent in the sense that none depends on the others. Evidence for a link between impact and extinction is strong but still needs more confirmation through bed-by-bed and laboratory studies. An important area for future research is the question of whether extinction is a continuous process, with the rate increasing at times of mass extinctions, or whether it is episodic at all scales. If the latter is shown to be generally true, then species are at risk of extinction only rarely during their existence and catastrophism, in the sense of isolated events of extreme stress, is indicated. This is line of reasoning can only be considered an hypothesis for testing. In a larger context, paleontologists may benefit from a research strategy that looks to known Solar System and Galactic phenomena for predictions about environmental effects on earth. The recent success in the recognition of Milankovitch Cycles in the late Pleistocene record is an example of the potential of this research area.

  9. Handbook of mass measurement

    CERN Document Server

    Jones, Frank E

    2002-01-01

    "How much does it weigh?" seems a simple question. To scientists and engineers, however, the answer is far from simple, and determining the answer demands consideration of an almost overwhelming number of factors.With an intriguing blend of history, fundamentals, and technical details, the Handbook of Mass Measurement sets forth the details of achieving the highest precision in mass measurements. It covers the whole field, from the development, calibration, and maintenance of mass standards to detailed accounts of weighing designs, balances, and uncertainty. It addresses the entire measurement process and provides in-depth examinations of the various factors that introduce error.Much of the material is the authors'' own work and some of it is published here for the first time. Jones and Schoonover are both highly regarded veterans of the U.S. National Institute of Standards and Technology. With this handbook, they have provided a service and resource vital to anyone involved not only in the determination of m...

  10. Masses of noble gases

    CERN Multimedia

    Marx, G H; Herfurth, F; Stora, T; Blaum, K; Beck, D; Audi, G; Rosenbusch, M

    The so-called magic numbers, cornerstones of the quantum nuclear ensemble, are now known to lose their supernatural powers far from the protected valley of stability. To complement the well-established (but not yet well-understood) case of N = 20, we propose to examine the erstwhile N = 28 shell closure via a measurement of the important (but unknown) mass of the nuclide $^{48}$Ar. The quenching of a shell closure, a mechanism as mysterious as the reason for magic numbers themselves, also has important consequences in nucleosynthesis. While $^{48}$Ar is not part of the region concerned by the canonical rapid neutro-capture r-process, the question of shell strength is of great importance for heavier nuclides. The location of the r-process path would benefit from extending the succesful ISOTRAP krypton mass measurements beyond the N = 58 sub-shell to $^{96-98}$Kr. Modeling the complementary rapid proton-capture rp- process, putative source of some proton-rich species, requires the mass of $^{70}$Kr, near the e...

  11. GalMass: A Smartphone Application for Estimating Galaxy Masses

    CERN Document Server

    Stewart, Kyle R

    2011-01-01

    This note documents the methods used by the smartphone application, "GalMass," which has been released on the Android Market. GalMass estimates the halo virial mass (Mvir), stellar mass (Mstar), gas mass (Mgas), and galaxy gas fraction of a central galaxy as a function of redshift (z<2), with any one of the above masses as an input parameter. In order to convert between Mvir and Mstar (in either direction), GalMass uses fitting functions that approximate the abundance matching models of either Conroy & Wechsler (2009), Moster et al. (2010), or Behroozi et al. (2010). GalMass uses a a semi-empirical fit to observed galaxy gas fractions to convert between Mstar and Mgas, as outlined in Stewart et al. (2009).

  12. NEW MESON MASS RELATION AND LOWEST PSEUDOSCALAR GLUEBALL MASS

    Institute of Scientific and Technical Information of China (English)

    WU NING; RUAN TU-NAN; ZHENG ZHI-PENG

    2001-01-01

    After considering its mixing with the glueball, we give a new mass relation for the meson nonet. According to this mass relation and the predicted mass of the pseudoscalar glueball given by lattice calculations and the effective Hamiltonian, the expected mass of the mixed pseudoscalar glueball is about 1.7 GeV. This result is helpful in the experimental search for the mixed isoscalar pseudoscalar glueball. η(1760) is discussed as a possible candidate for this type of particle.

  13. MASS SPECTROMETER LEAK

    Science.gov (United States)

    Shields, W.R.

    1960-10-18

    An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

  14. Twisted mass lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Shindler, A. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2007-07-15

    I review the theoretical foundations, properties as well as the simulation results obtained so far of a variant of the Wilson lattice QCD formulation: Wilson twisted mass lattice QCD. Emphasis is put on the discretization errors and on the effects of these discretization errors on the phase structure for Wilson-like fermions in the chiral limit. The possibility to use in lattice simulations different lattice actions for sea and valence quarks to ease the renormalization patterns of phenomenologically relevant local operators, is also discussed. (orig.)

  15. The Cepheid mass discrepancy and pulsation-driven mass loss

    NARCIS (Netherlands)

    Neilson, H.R.; Cantiello, M.; Langer, N.

    2011-01-01

    Context. A longstanding challenge for understanding classical Cepheids is the Cepheid mass discrepancy, where theoretical mass estimates using stellar evolution and stellar pulsation calculations have been found to differ by approximately 10−20%. Aims. We study the role of pulsation-driven mass loss

  16. In Situ Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  17. Understanding neutrino masses and mixings

    Indian Academy of Sciences (India)

    R N Mohapatra

    2004-02-01

    We discuss ways to understand large neutrino mixings using new symmetries of quarks and leptons beyond the standard model for the three allowed patterns of neutrino masses: normal, inverted hierarchy and degenerate masses.

  18. Biomedical accelerator mass spectrometry

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  19. Archimedes Mass Filter Vaporizer

    Science.gov (United States)

    Putvinski, S.; Agnew, A. F.; Cluggish, B. P.; Ohkawa, T.; Sevier, L.; Umstadter, K. R.; Dresvin, S. V.; Kuteev, B. V.; Feygenson, O. N.; Ivanov, D. V.; Zverev, S. G.; Miroshnikov, I. V.; Egorov, S. M.; Kiesewetter, D. V.; Maliugin, V. I.

    2001-10-01

    Archimedes Technology Group, Inc., is developing a plasma mass separator called the Archimedes Filter that separates waste oxide mixtures ion by ion into two mass groups: light and heavy. Since high-level waste at Hanford has 99.9its radioactivity associated with heavy elements, the Archimedes Filter can effectively decontaminate over three-quarters of that waste. The Filter process involves some preprocessing followed by volatilization and separation by the magnetic and electric fields of the main plasma. This presentation describes the approach to volatilization of the waste oxy-hydroxide mixture by means of a very high heat flux (q > 10 MW/m2). Such a high heat flux is required to ensure congruent evaporation of the complex oxy-hydroxide mixture and is achieved by injection of small droplets of molten waste into an inductively coupled plasma (ICP) torch. This presentation further addresses different issues related to evaporation of the waste including modeling of droplet evaporation, estimates of parameters of plasma torch, and 2D modeling of the plasma. The experimental test bed for oxide vaporization and results of the initial experiments on oxide evaporation in 60 kW ICP torch will also be described.

  20. Peak mass and dynamical friction

    CERN Document Server

    Del Popolo, A

    1995-01-01

    We show how the results given by several authors relatively to the mass of a density peak are changed when small scale substructure induced by dynamical friction are taken into account. The peak mass obtained is compared to the result of Peacock \\& Heavens (1990) and to the peak mass when dynamical friction is absent to show how these effects conspire to reduce the mass accreted by the peak.

  1. Localizability and the planck mass

    Energy Technology Data Exchange (ETDEWEB)

    Ne`eman, Y. [Tel-Aviv Univ. (Israel). Sackler Faculty of Exact Sciences]|[Univ. of Texas, Austin, TX (United States). Center for Particle Physics

    1993-06-01

    The author combines the assumption of environmental decoherence, as the mechanism generating the classical (i.e. no quantum interferences) nature of spacetime, with the limit on its other classical feature, point-like continuity, namely Planck length. As a result, quantum extended objects with masses larger than Planck mass have to derive their quantum behavior from long-range correlations; objects with masses smaller than Planck mass cannot display classical behavior.

  2. Neutrino Oscillations with Nil Mass

    CERN Document Server

    Floyd, Edward R

    2016-01-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and $\\bar{\

  3. Neutrino Oscillations with Nil Mass

    Science.gov (United States)

    Floyd, Edward R.

    2016-09-01

    An alternative neutrino oscillation process is presented as a counterexample for which the neutrino may have nil mass consistent with the standard model. The process is developed in a quantum trajectories representation of quantum mechanics, which has a Hamilton-Jacobi foundation. This process has no need for mass differences between mass eigenstates. Flavor oscillations and ν ,bar{ν } oscillations are examined.

  4. Mass Transfer with Chemical Reaction.

    Science.gov (United States)

    DeCoursey, W. J.

    1987-01-01

    Describes the organization of a graduate course dealing with mass transfer, particularly as it relates to chemical reactions. Discusses the course outline, including mathematics models of mass transfer, enhancement of mass transfer rates by homogeneous chemical reaction, and gas-liquid systems with chemical reaction. (TW)

  5. Mass Transfer with Chemical Reaction.

    Science.gov (United States)

    DeCoursey, W. J.

    1987-01-01

    Describes the organization of a graduate course dealing with mass transfer, particularly as it relates to chemical reactions. Discusses the course outline, including mathematics models of mass transfer, enhancement of mass transfer rates by homogeneous chemical reaction, and gas-liquid systems with chemical reaction. (TW)

  6. Maximum stellar iron core mass

    Indian Academy of Sciences (India)

    F W Giacobbe

    2003-03-01

    An analytical method of estimating the mass of a stellar iron core, just prior to core collapse, is described in this paper. The method employed depends, in part, upon an estimate of the true relativistic mass increase experienced by electrons within a highly compressed iron core, just prior to core collapse, and is significantly different from a more typical Chandrasekhar mass limit approach. This technique produced a maximum stellar iron core mass value of 2.69 × 1030 kg (1.35 solar masses). This mass value is very near to the typical mass values found for neutron stars in a recent survey of actual neutron star masses. Although slightly lower and higher neutron star masses may also be found, lower mass neutron stars are believed to be formed as a result of enhanced iron core compression due to the weight of non-ferrous matter overlying the iron cores within large stars. And, higher mass neutron stars are likely to be formed as a result of fallback or accretion of additional matter after an initial collapse event involving an iron core having a mass no greater than 2.69 × 1030 kg.

  7. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  8. Mass measurement of radioactive isotopes

    CERN Document Server

    Kluge, H J; Scheidenberger, C

    2004-01-01

    The highest precision in mass measurements on short-lived radionuclides is obtained using trapping and cooling techniques. Here, the experimental storage ring (ESR) at GSI/Darmstadt and the tandem Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN play an important role. Status and recent results on mass measurements of radioactive nuclides with ESR and ISOLTRAP are summarized.

  9. Mass Transport within Soils

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.

    2009-03-01

    Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated

  10. Masses for Galactic Beat Cepheids

    Science.gov (United States)

    D'Cruz, Noella L.; Morgan, Siobahn M.; Böhm-Vitense, Erika

    2000-08-01

    Accurate mass determinations for Cepheids may be used to determine the degree of excess mixing in the interiors of their main-sequence progenitors: the larger the excess mixing, the larger the luminosity of the Cepheid of a given mass, or the smaller the mass of a Cepheid with given luminosity. Dynamical masses determined recently for a few Cepheid binaries indicate excess mixing somewhat stronger than that corresponding to the convective overshoot models by Schaller et al. Beat Cepheids can be used similarly to test main-sequence mixing in stellar interiors. The period ratios for beat Cepheids depend on luminosity, Teff, heavy element abundance, and mass. By comparing pulsational models and the observationally derived luminosity, Teff, metallicities, and period ratios it is possible to obtain masses for these stars, the so-called beat masses. With the old opacities masses much smaller than the evolutionary masses were obtained. With the new OPAL opacities a beat mass close to the dynamical mass was obtained for the binary beat Cepheid Y Carinae, showing that it is now possible to obtain reliable beat masses. In this paper, we determine beat masses for seven Galactic beat Cepheids for which photometric and spectroscopic data are available. We find an average mass around 4.2+/-0.3 Msolar for these stars, though the actual error limits for each star may be larger mainly because of uncertainties in E(B-V) and the heavy element abundances. (As derived spectroscopically, beat Cepheids are in general metal-poor, with -0.4relation between the derived beat masses and the luminosities again indicates excess mixing that is somewhat larger than that corresponding to the models by Schaller et al.

  11. The Mass Media

    DEFF Research Database (Denmark)

    Valentini, Chiara; Laursen, Bo

    2012-01-01

    This chapter deals with the EU institutions’ external communication and how it relates to the European public sphere(s). We argue that one of the preconditions for establishing a well-functioning European public sphere is that the EU institutions’ decision-making and political debates around...... policies and issues are organised in such a way that the European citizens 1) are informed of the actions of European political leaders and top executives in ways that appeal to a wide range of publics, and 2) are encouraged to discuss and enter in a dialogue about these issues in appropriate communicative...... spaces. We postulate that citizens’ levels of awareness and knowledge of EU matters depend on the EU institutions’ ability to reach European citizens directly or indirectly through a wide range of channels, including the mass media. Citizens’ participation in political debates, however, requires more...

  12. Mass for the graviton

    CERN Document Server

    Visser, M

    1998-01-01

    Can we give the graviton a mass? Does it even make sense to speak of a massive graviton? In this essay I shall answer these questions in the affirmative. I shall outline an alternative to Einstein Gravity that satisfies the Equivalence Principle and automatically passes all classical weak-field tests (GM/r approx 10^{-6}). It also passes medium-field tests (GM/r approx 1/5), but exhibits radically different strong-field behaviour (GM/r approx 1). Black holes in the usual sense do not exist in this theory, and large-scale cosmology is divorced from the distribution of matter. Furthermore, the cosmological constant is a non-issue in this theory. To do all this we have to sacrifice something: the theory exhibits prior geometry, and depends on a non-dynamical background metric.

  13. Heat and mass transfer

    CERN Document Server

    Karwa, Rajendra

    2017-01-01

    This textbook presents the classical treatment of the problems of heat transfer in an exhaustive manner with due emphasis on understanding of the physics of the problems. This emphasis is especially visible in the chapters on convective heat transfer. Emphasis is laid on the solution of steady and unsteady two-dimensional heat conduction problems. Another special feature of the book is a chapter on introduction to design of heat exchangers and their illustrative design problems. A simple and understandable treatment of gaseous radiation has been presented. A special chapter on flat plate solar air heater has been incorporated that covers thermo-hydraulic modeling and simulation. The chapter on mass transfer has been written looking specifically at the needs of the students of mechanical engineering. The book includes a large number and variety of solved problems with supporting line diagrams. The author has avoided duplicating similar problems, while incorporating more application-based examples. All the end-...

  14. Sustainability Evaluation of Mass Customization

    DEFF Research Database (Denmark)

    Brunø, Thomas Ditlev; Nielsen, Kjeld; Taps, Stig B.

    2013-01-01

    This paper addresses the issue whether the concepts mass customization and sustainability are fundamentally compatible by asking the question: can a mass customized product be sustainable? Some factors indicate that mass customized products are less sustainable than standardized products; however...... other factors suggest the opposite. This paper explores these factors during three life cycle phases for a product: Production, Use and End of Life. It is concluded that there is not an unambiguous causal relationship between mass customization and sustainability; however several factors unique to mass...

  15. Determination of Effective Thoracic Mass

    Directory of Open Access Journals (Sweden)

    Jeffrey H. Marcus

    1996-01-01

    Full Text Available Effective thoracic mass is an important parameter in specifying mathematical and mechanical models (such as crash dummies of humans exposed to impact conditions. A method is developed using a numerical optimizer to determine effective thoracic mass (and mass distribution given a number of acceleration signals and a force signal response. Utilizing previously reported lateral and frontal impact tests with human cadaveric test specimens in a number of different conditions, the effective thoracic mass is computed. The effective thoracic masses are then computed for a variety of crash dummies exposed to identical test conditions.

  16. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

    Full Text Available Solar eruptive phenomena embrace a variety of eruptions, including flares, solar energetic particles, and radio bursts. Since the vast majority of these are associated with the eruption, development, and evolution of coronal mass ejections (CMEs, we focus on CME observations in this review. CMEs are a key aspect of coronal and interplanetary dynamics. They inject large quantities of mass and magnetic flux into the heliosphere, causing major transient disturbances. CMEs can drive interplanetary shocks, a key source of solar energetic particles and are known to be the major contributor to severe space weather at the Earth. Studies over the past decade using the data sets from (among others the SOHO, TRACE, Wind, ACE, STEREO, and SDO spacecraft, along with ground-based instruments, have improved our knowledge of the origins and development of CMEs at the Sun and how they contribute to space weather at Earth. SOHO, launched in 1995, has provided us with almost continuous coverage of the solar corona over more than a complete solar cycle, and the heliospheric imagers SMEI (2003 – 2011 and the HIs (operating since early 2007 have provided us with the capability to image and track CMEs continually across the inner heliosphere. We review some key coronal properties of CMEs, their source regions and their propagation through the solar wind. The LASCO coronagraphs routinely observe CMEs launched along the Sun-Earth line as halo-like brightenings. STEREO also permits observing Earth-directed CMEs from three different viewpoints of increasing azimuthal separation, thereby enabling the estimation of their three-dimensional properties. These are important not only for space weather prediction purposes, but also for understanding the development and internal structure of CMEs since we view their source regions on the solar disk and can measure their in-situ characteristics along their axes. Included in our discussion of the recent developments in CME

  17. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  18. Low mass integrated cooling

    CERN Document Server

    Mapelli, Alessandro

    2014-01-01

    Low mass on - detec tor cooling systems are being developed and stud ied by the Detector Technology group (PH - DT) in the CERN Physics Department in close collaboration with LHC and non - LHC experiments . Two approaches are currently being investigated. The first approach, for barrel configurations, consists in integrating the cooli ng apparatus in light mechanical structures support ing the detectors. In this case , the thermal management can be achieved either with light cooling pipes and thin plates or with a network of microchannels embedded in thin strips of silicon or polyimide . Both configuratio ns are being investigated in the context of the 2018 upgrade program of the ALICE Inner Tracking System (ITS). Moreover, it is also possible to use a s ilicon microchannel cooling device itself as structural support for the detectors and electronics. Such a configur ation has been adopted by the NA62 collaboration for the ir GigaTracKer (GTK) as well as by the LHCb collaboration for the 2018 major upgrade of...

  19. "Gravitational mass" of information?

    CERN Document Server

    Kish, Laszlo B

    2007-01-01

    We hypothesize possible new types of forces that would be the result of new types of interactions, static and a slow transient, between objects with related information contents (pattern). Such mechanism could make material composition dependence claimed by Fishbach, et al in Eotvos type experiments plausible. We carried out experiments by using a high-resolution scale with the following memories: USB-2 flash drives (1-16GB), DVD and CD disks to determine if such an interaction exist/detectable with a scale resolution of 10 microgram with these test objects. We applied zero information, white noise and 1/f noise type data. Writing or deleting the information in any of these devices causes peculiar negative weight transients, up to milligrams (mass fraction around 10^-5), which is followed by various types of relaxation processes. These relaxations have significantly different dynamics compared to transients observed during cooling after stationary external heating. Interestingly, a USB-1 MP3 player has also d...

  20. Polaris: Mass and Multiplicity

    CERN Document Server

    Evans, N R; Bond, H E; Nelan, E; Bono, G; Karovska, M; Wolk, S; Sasselov, D; Guinan, E; Engle, S; Schlegel, E M; Mason, B; Evans, Nancy Remage; Schaefer, Gail; Bond, Howard E.; Nelan, Edmund; Bono, Giuseppe; Karovska, Margarita; Wolk, Scott; Sasselov, Dimitar; Guinan, Edward; Engle, Scott; Schlegel, Eric; Mason, Brian

    2006-01-01

    Polaris, the nearest and brightest classical Cepheid, is a member of at least a triple system. It has a wide ($18''$) physical companion, the F-type dwarf Polaris B. Polaris itself is a single-lined spectroscopic binary with an orbital period of 30 years (Kamper, 1996, JRASC, 90, 140). By combining {\\it Hipparcos} measurements of the instantaneous proper motion with long-term measurements and the Kamper radial-velocity orbit, Wielen et al. (2000, A&A, 360, 399) have predicted the astrometric orbit of the close companion. Using the {\\it Hubble Space Telescope} and the Advanced Camera for Surveys' High-Resolution Channel with an ultraviolet (F220W) filter, we have now directly detected the close companion. Based on the Wielen et al. orbit, the {\\it Hipparcos} parallax, and our measurement of the separation ($0.176''$ $\\pm$ $0.002''$), we find a preliminary mass of 5.0 $\\pm$ 1.5 M$_{\\odot}$ for the Cepheid and 1.38 $\\pm$ 0.61 M$_{\\odot}$ for the close companion. These values will be refined by additional {\\i...

  1. Top mass reconstruction in ATLAS

    CERN Document Server

    Neusiedl, A; The ATLAS collaboration

    2011-01-01

    The top-quark mass is a fundamental parameter of the Standard Model. After the discovery of the top quark, the measurements of its properties were of substantial interest. Within the framework of the SM, the top-quark mass can be used in combination with other electroweak precision measurements to constrain the mass of the yet unobserved Higgs boson.\\\\ In the new era of the Large Hadron Collider (LHC), the first top quarks have been produced in Europe in proton-proton collisions at a center-of-mass energy of 7~TeV. The top-quark mass measurement of ATLAS in the so called lepton+jets channel with 35~pb$^{-1}$ integrated luminosity is presented. In this early data-taking period the largest uncertainty on this measurement comes from the knowledge of the jet energy scale. It is shown how this uncertainty is determined and which methods are used for measuring the top-quark mass.

  2. Video Games as Mass Art

    Directory of Open Access Journals (Sweden)

    Grant Tavinor

    2011-01-01

    Full Text Available Videogames are one of the most significant developments in the mass arts of recent times. In commercial terms, they are now among the most prominent of the mass arts worldwide. This commercial and cultural success does not exhaust the interest in videogames as a mass art phenomenon because games such as Grand Theft Auto IV and Fallout 3 are structurally radically different from previous forms of mass art. In particular, the ontology of videogames, the nature and identity of their works, and how they are instanced and evaluated is a departure from the familiar mass arts of film and popular music. This paper explores these differences in an attempt to fit videogames into a theory of mass art, but also to provide guidance on the issues of criticism and evaluation that surely follow from their ontological distinctiveness.

  3. [Eating disorders and mass media].

    Science.gov (United States)

    Peroutsi, A; Gonidakis, F

    2011-01-01

    During the last 50 years, eating disorders have developed to a complicated and widespread medical and social issue. The latest research results indicate that eating disorders have a quite complicated and multifactorial etiology. According to the multifactorial etiological model, the impact of mass media can be regarded mainly as a precipitating factor. The literature review showed that mass media have a considerable impact on the development and perpetuation of eating disorders. Mass media contribute to the promotion of the thinness ideal as a way to achieve social approval, recognition and success. Mass media also promote dieting and food deprivation, as a successful way of life or as a socially agreeable practice. Furthermore, the literature review showed that mass media remain the main source of information about eating disorders. Considering the above result, mass media could play a major role in the promotion of prevention practices and early diagnosis and treatment of eating disorders.

  4. Hyperon masses in nuclear matter

    CERN Document Server

    Savage, M J; Savage, Martin J; Wise, Mark B

    1996-01-01

    We analyze hyperon and nucleon mass shifts in nuclear matter using chiral perturbation theory. Expressions for the mass shifts that include strong interaction effects at leading order in the density are derived. Corrections to our results are suppressed by powers of the Fermi momentum divided by either the chiral symmetry breaking scale or the nucleon mass. Our work is relevant for neutron stars and for large hypernuclei.

  5. Black Holes with Zero Mass

    CERN Document Server

    Nucamendi, U; Nucamendi, Ulises; Sudarsky, Daniel

    2000-01-01

    We consider the spacetimes corresponding to static Global Monopoles with interior boundaries corresponding to a Black Hole Horizon and analyze the behavior of the appropriate ADM mass as a function of the horizon radius r_H. We find that for small enough r_H, this mass is negative as in the case of the regular global monopoles, but that for large enough r_H the mass becomes positive encountering an intermediate value for which we have a Black Hole with zero ADM mass.

  6. Mass loss and stellar superwinds

    CERN Document Server

    Vink, Jorick S

    2016-01-01

    Mass loss bridges the gap between massive stars and supernovae (SNe) in two major ways: (i) theoretically it is the amount of mass lost that determines the mass of the star prior to explosion, and (ii) observations of the circumstellar material around SNe may teach us the type of progenitor that made the SN. Here, I present the latest models and observations of mass loss from massive stars, both for canonical massive O stars, as well as very massive stars (VMS) that show Wolf-Rayet type features.

  7. Review of atomic mass formula

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Takahiro [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

    1997-07-01

    Wapstra and Audi`s Table is famous for evaluation of experimental data of atomic nuclear masses (1993/1995 version) which estimated about 2000 kinds of nuclei. The error of atomic mass of formula is 0.3 MeV-0.8 MeV. Four kinds of atomic mass formula: JM (Jaenecke and Masson), TUYY (Tachibana, Uno, Yamada and Yamada), FRDM (Moeller, Nix, Myers and Swiatecki) and ETFSI (Aboussir, Pearson, Dutta and Tondeur) and their properties (number of parameter and error etc.) were explained. An estimation method of theoretical error of mass formula was presented. It was estimated by the theoretical error of other surrounding nuclei. (S.Y.)

  8. Luxury for the masses.

    Science.gov (United States)

    Silverstein, Michael J; Fiske, Neil

    2003-04-01

    Increasingly wide income disparities, higher levels of education, and greater awareness of other cultures' ideas of the good life have given rise to a new class of American consumer. And a new category of products and services, including automobiles, apparel, food, wine, and spirits, has sprung into being to cater to it. That category is called new luxury. America's middle-market consumers are trading up to higher levels of quality and taste than ever before. Members of the middle market (those earning $50,000 and above annually) collectively have around $1 trillion of disposable income. And they will pay premiums of 20% to 200% for well-designed, well-engineered, and well-crafted goods that can't be found in the mass middle market and that have the artisanal touches of traditional luxury items. Most important, even when they address basic necessities, such goods evoke and engage consumers' emotions while feeding their aspirations for a better life. Supply-side forces are essential to the rise of new luxury. Like the consumers of their goods, entrepreneurs are better educated and more sophisticated about their customers than ever before. In addition, global sourcing, falling trade barriers and transportation costs, and rising offshore manufacturing standards are making possible the economical production of alluring products of high quality. Unlike old-luxury goods, new-luxury products can generate high sales volumes despite their relatively high prices. As a result, new-luxury companies are achieving levels of profitability and growth beyond the reach of their conventional competitors. Whether the item in question is a $6 Panera sandwich or a $30,000 Mercedes, new luxury is a formula that middle-market companies, facing erosion of their market share by high-end and low-end producers, can ill afford to ignore.

  9. Static-light meson masses from twisted mass lattice QCD

    CERN Document Server

    Jansen, K; Shindler, A; Wagner, M

    2008-01-01

    We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV. We have extrapolated our results, to make predictions regarding the spectrum of B and B_s mesons.

  10. Virtual mass effect in dynamic micromechanical mass sensing in liquids

    Science.gov (United States)

    Peiker, P.; Oesterschulze, E.

    2016-06-01

    Weighing individual micro- or nanoscale particles in solution using dynamic micromechanical sensors is quite challenging: viscous losses dramatically degrade the sensor's performance by both broadening the resonance peak and increasing the effective total mass of the resonator by the dragged liquid. While the virtual mass of the resonator was discussed frequently, little attention has been paid to the virtual mass of particles attached to the resonator's surface and its impact on the accuracy of mass sensing. By means of the in situ detection of a polystyrene microbead in water using a bridge-based microresonator, we demonstrate that the virtual mass of the bead significantly affects the observed frequency shift. In fact, 55 % of the frequency shift was caused by the virtual mass of the adsorbed bead, predicted by Stoke's theory. Based on the observed shift in the resonator's quality factor during particle adsorption, we confirm this significant effect of the virtual mass. Thus, a quantitative analysis of the mass of a single adsorbed particle is strongly diminished if dynamic micromechanical sensors are operated in a liquid environment.

  11. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja

    2009-01-01

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise...

  12. Black-Hole Mass Measurements

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2004-01-01

    The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized.......The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized....

  13. Linear electric field mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McComas, D.J.; Nordholt, J.E.

    1991-03-29

    A mass spectrometer is described having a low weight and low power requirement, for use in space. It can be used to analyze the ionized particles in the region of the spacecraft on which it is mounted. High mass resolution measurements are made by timing ions moving through a gridless cylindrically sysmetric linear electric field.

  14. Mass Notification for Higher Education

    Science.gov (United States)

    Schneider, Tod

    2010-01-01

    Mass notification is a high priority in educational institutions. As the number of electronic communication devices has diversified, so has the complexity of designing an effective mass notification system. Picking the right system, with the right features, support services and price, can be daunting. This publication, updated quarterly due to…

  15. Mass Extinctions Past and Present.

    Science.gov (United States)

    Allmon, Warren Douglas

    1987-01-01

    Discusses some parallels that seem to exist between mass extinction recognizable in the geologic record and the impending extinction of a significant proportion of the earth's species due largely to tropical deforestation. Describes some recent theories of causal factors and periodicities in mass extinction. (Author/TW)

  16. Mass Spectrometry Instrumentation in Proteomics

    DEFF Research Database (Denmark)

    Sprenger, Richard Remko; Roepstorff, Peter

    2012-01-01

    Mass spectrometry has evolved into a crucial technology for the field of proteomics, enabling the comprehensive study of proteins in biological systems. Innovative developments have yielded flexible and versatile mass spectrometric tools, including quadrupole time-of-flight, linear ion trap...

  17. Mass Mentality, Culture Industry, Fascism

    Directory of Open Access Journals (Sweden)

    Saladdin Said Ahmed

    2008-06-01

    Full Text Available Some fashionable leftist movements and populist intellectuals habitually blame the sources of information for public ignorance about the miserable state of the world. It could be argued, however, that the masses are ignorant because they prefer ignorance. A mass individual is politically apathetic and intellectually lazy. As a result, even when huge amounts of information are available, which is the case in this epoch, the masses insist on choosing ignorance. It is true that there is not enough information about what has happened in a place such as Darfur, but the masses choose not to access even the amount of information that is available. The great majority of people in China, Iran, and America, despite the fact that they have varying amounts of access to various types of "knowledge," still tend to be misinformed. It seems that a mass individual is curious only about what directly affects his/her own personal life. I will explore the connection between mass mentality and the culture industry in order to capture the essential role of the former in the latter. I will also argue that a mass individual is the source of fascism although fascism as a phenomenon needs a mass culture in which to flourish.

  18. Digital Integration: Towards Mass Customization

    DEFF Research Database (Denmark)

    Schou, Finn

    Mass production in lots of one” is a phrase coined by Oliver Morton in a seminal piece for The Economist (1994). In few words this sentence contains the essence (and schism) of true customization aiming at manufacturing the artifact for the mass. Emerging Nanotechnologies are said to enable...

  19. Macro-microscopic mass formulae and nuclear mass predictions

    Science.gov (United States)

    Royer, G.; Guilbaud, M.; Onillon, A.

    2010-12-01

    Different mass formulae derived from the liquid drop model and the pairing and shell energies of the Thomas-Fermi model have been studied and compared. They include or not the diffuseness correction to the Coulomb energy, the charge exchange correction term, the curvature energy, different forms of the Wigner term and powers of the relative neutron excess I=(N-Z)/A. Their coefficients have been determined by a least square fitting procedure to 2027 experimental atomic masses (G. Audi et al. (2003) [1]). The Coulomb diffuseness correction Z/A term or the charge exchange correction Z/A term plays the main role to improve the accuracy of the mass formula. The Wigner term and the curvature energy can also be used separately but their coefficients are very unstable. The different fits lead to a surface energy coefficient of around 17-18 MeV. A large equivalent rms radius ( r=1.22-1.24 fm) or a shorter central radius may be used. An rms deviation of 0.54 MeV can be reached between the experimental and theoretical masses. The remaining differences come probably mainly from the determination of the shell and pairing energies. Mass predictions of selected expressions have been compared to 161 new experimental masses and the correct agreement allows to provide extrapolations to masses of 656 selected exotic nuclei.

  20. Light baryon masses with dynamical twisted mass fermions

    CERN Document Server

    Alexandrou, C; Blossier, B; Brinet, M; Carbonell, J; Dimopoulos, P; Drach, V; Farchioni, F; Frezzotti, R; Guichon, P; Herdoiza, G; Jansen, K; Korzec, T; Koutsou, G; Liu, Z; Michael, C; Pène, O; Shindler, A; Urbach, C; Wenger, U

    2008-01-01

    We present results on the mass of the nucleon and the Delta using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of about 300-600 MeV on lattices of 2.1-2.7 fm. We check for cut-off effects by evaluating these baryon masses on lattices of spatial size 2.1 fm at beta=3.9 and beta=4.05 and on a lattice of 2.4 fm at beta=3.8. The values we find are compatible within our statistical errors. Lattice results are extrapolated to the physical limit using continuum chiral perturbation theory. Performing a combined fit to our lattice data at beta=3.9 and beta=4.05 we find a nucleon mass of 964\\pm 28 (stat.) \\pm 8 (syst.) MeV. The nucleon mass at the physical point provides an independent determination of the lattice spacing. Using heavy baryon chiral perturbation theory at O(p^3) we find a_{\\beta=3.9}=0.0890\\pm 0.0039(stat.) \\pm 0.0014(syst.) fm, and a_{\\beta=4.05}= 0.0691\\pm 0.0034(stat.) \\pm 0.0010(syst.) fm, in good agreement w...

  1. The evolution of the stellar mass versus halo mass relationship

    CERN Document Server

    Mitchell, Peter; Baugh, Carlton; Cole, Shaun

    2015-01-01

    We present an analysis of the predictions made by the Galform semi-analytic galaxy formation model for the evolution of the relationship between stellar mass and halo mass. We show that for the standard implementations of supernova feedback and gas reincorporation used in semi-analytic models, this relationship is predicted to evolve weakly over the redshift range 0mass versus halo mass (SHM) relationship implicitly requires that, at fixed halo mass, the efficiency of stellar mass assembly must be almost constant with cosmic time. We show that in our model, this behaviour can be understood in simple terms as a result of a constant efficiency of gas reincorporation, and an efficiency of SNe feedback that is, on average, constant at fixed halo mass. We present a simple explanation of how feedback from active galactic nuclei (AGN) acts in our model to introduce a break in the SHM relation whose location is predicted to evolve only modestly. Finally, we show that...

  2. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  3. Unitarity and Complex Mass Fields

    Science.gov (United States)

    Bollini, C. G.; Oxman, L. E.

    We consider a field obeying a simple higher order equation with a real mass and two complex conjugate mass parameters. The evaluation of vacuum expectation values leads to the propagators, which are (resp.) a Feynman causal function and two complex conjugate Wheeler-Green functions (half retarded plus half advanced). By means of the computation of convolutions, we are able to show that the total self-energy has an absorptive part which is only due to the real mass. In this way it is shown that this diagram is compatible with unitarity and the elimination of free complex-mass asymptotic states from the set of external legs of the S-matrix. It is also shown that the complex masses act as regulators of ultraviolet divergences.

  4. International Mass Spectrometry Society (IMSS).

    Science.gov (United States)

    Cooks, R G; Gelpi, E; Nibbering, N M

    2001-02-01

    This paper gives a brief description of the recently formalized International Mass Spectrometry Society (IMSS). It is presented here in order to increase awareness of the opportunities for collaboration in mass spectrometry in an international context. It also describes the recent 15th International Mass Spectrometry Conference, held August/September 2000, in Barcelona. Each of the authors is associated with the IMSS. The 15th Conference, which covers all of mass spectrometry on a triennial basis, was chaired by Professor Emilio Gelpi of the Instituto de Investigaciones Biomedicas, Barcelona. The outgoing and founding President of the IMSS is Professor Graham Cooks, Purdue University, and the incoming President is Professor Nico Nibbering, University of Amsterdam. Similar material has been provided to the Editors of other journals that cover mass spectrometry.

  5. The 2012 Atomic Mass Evaluation and the Mass Tables

    Energy Technology Data Exchange (ETDEWEB)

    Audi, G., E-mail: amdc.audi@gmail.com [CSNSM, CNRS/IN2P3, Université Paris-Sud, F-91405 Orsay Campus (France); Wang, M. [CSNSM-Orsay, Institute of Modern Physics, Lanzhou 730000 (China); MPI-K, D-69117 Heidelberg (Germany); Wapstra, A.H. [NIKHEF, 1009DB Amsterdam (Netherlands); Kondev, F.G. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); MacCormick, M. [IPN, CNRS/IN2P3, Université Paris-Sud, F-91406 Orsay cedex (France); Xu, X. [IMP, Lanzhou 730000 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China)

    2014-06-15

    The new evaluation of the Atomic Masses, Ame2012, has just been released. It represents a major step in the history of the 60 year old Atomic Mass Evaluation based on the method developed by Wapstra. This new publication includes all material available to date. Some of the policies and procedures used in our evaluation are reported, together with an illustration of one specially difficult case, the energy available for the {sup 102}Pd double-electron capture. The observation of the mass surface reveals many important new features. We illustrate this statement by the double magicity of {sup 270}Hs at N = 162 and Z = 108.

  6. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  7. Intermediate-Mass Black Holes

    CERN Document Server

    Miller, M C

    2004-01-01

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (roughly 3-20 solar masses), which are produced by the core collapse of massive stars, and supermassive (millions to billions of solar masses), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with hundreds to thousands of solar masses. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work t...

  8. Dark Matter with Variable Masses

    Science.gov (United States)

    García-Bellido, Juan

    String effective theories contain a dilaton scalar field which couples to gravity, matter and radiation. In general, particle masses will have different dilaton couplings. We can always choose a conformal frame in which baryons have constant masses while (nonbaryonic) dark matter have variable masses, in the context of a scalar-tensor gravity theory. We are interested in the phenomenology of this scenario. Dark matter with variable masses could have a measurable effect on the dynamical motion of the halo of spiral galaxies, which may affect cold dark matter models of galaxy formation. As a consequence of variable masses, the energy-momentum tensor is not conserved; there is a dissipative effect, due to the dilaton coupling, associated with a “dark entropy” production. In particular, if axions had variable masses they could be diluted away, thus opening the “axion window.” Assuming that dark matter with variable masses dominates the cosmological evolution during the matter era, it will affect the primordial nucleosynthesis predictions on the abundances of light elements. Furthermore, the dilaton also couples to radiation in the form of a variable gauge coupling. Experimental bounds will constrain the parameters of this model.

  9. Current Direct Neutrino Mass Experiments

    Directory of Open Access Journals (Sweden)

    G. Drexlin

    2013-01-01

    Full Text Available In this contribution, we review the status and perspectives of direct neutrino mass experiments, which investigate the kinematics of β-decays of specific isotopes (3H, 187Re, 163Ho to derive model-independent information on the averaged electron (antineutrino mass. After discussing the kinematics of β-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re. We then describe the Karlsruhe Tritium Neutrino (KATRIN experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.. To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium β-decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

  10. High-Resolution Mass Spectrometers

    Science.gov (United States)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  11. Mass measurements with a Penning trap mass spectrometer at ISOLDE

    CERN Document Server

    Bollen, G; Audi, G; Beck, D; Herfurth, F; Kluge, H J; Kohl, A; Lunney, M D; Moore, R B; De Saint-Simon, M; Schark, E; Schwarz, S; Szerypo, J

    1998-01-01

    Penning trap mass measurements on radioactive isotopes are performed with the ISOLTRAP mass spectrometer at ISOLDE/CERN. In the last years the applicability of the spectrometer has been considerably extended. The most recent measurements were carried out on isotopes of rare earth elements and on isotopes with Z=80-85. An accuracy of $\\delta$ m/m approximately=1$\\cdot$10$^{-7}$was achieved. (19 refs).

  12. Neutrino mass as the probe of intermediate mass scales

    Energy Technology Data Exchange (ETDEWEB)

    Senjanovic, G.

    1980-01-01

    A discussion of the calculability of neutrino mass is presented. The possibility of neutrinos being either Dirac or Majorana particles is analyzed in detail. Arguments are offered in favor of the Majorana case: the smallness of neutrino mass is linked to the maximality of parity violation in weak interactions. It is shown how the measured value of neutrino mass would probe the existence of an intermediate mass scale, presumably in the TeV region, at which parity is supposed to become a good symmetry. Experimental consequences of the proposed scheme are discussed, in particular the neutrino-less double ..beta.. decay, where observation would provide a crucial test of the model, and rare muon decays such as ..mu.. ..-->.. e..gamma.. and ..mu.. ..-->.. ee anti e. Finally, the embedding of this model in an O(10) grand unified theory is analyzed, with the emphasis on the implications for intermediate mass scales that it offers. It is concluded that the proposed scheme provides a distinct and testable alternative for understanding the smallness of neutrino mass. 4 figures.

  13. Mass Spectrometry in Polymer Chemistry

    CERN Document Server

    Barner-Kowollik, Christopher; Falkenhagen, Jana; Weidner, Steffen

    2011-01-01

    Combining an up-to-date insight into mass-spectrometric polymer analysis beyond MALDI with application details of the instrumentation, this is a balanced and thorough presentation of the most important and widely used mass-spectrometric methods.Written by the world's most proficient experts in the field, the book focuses on the latest developments, covering such technologies and applications as ionization protocols, tandem and liquid chromatography mass spectrometry, gas-phase ion-separation techniques and automated data processing. Chapters on sample preparation, polymer degradation and the u

  14. Mass-movementの起源

    OpenAIRE

    藤田, 至則; Fujita, Yukinori

    1985-01-01

    Mass-movement is a general term for disasters in the mountains and hilly lands, such as falls, slides and flow (TAKEI, 1980). It has been revealed that these phenomena were repeated since geologic times. Occurrence of the so-called primary mass-movement to be generated in the virgin areas of mountains and hills is scarce at the present time, but it must have taken place during a certain geologic age on a large scale in both number and quantity, and it is called today a buried mass-movement or...

  15. MASS CUSTOMIZATION and PRODUCT MODELS

    DEFF Research Database (Denmark)

    Svensson, Carsten; Malis, Martin

    2003-01-01

    to the product. Through the application of a mass customization strategy, companies have a unique opportunity to create increased customer satisfaction. In a customized production, knowledge and information have to be easily accessible since every product is a unique combination of information. If the dream...... of a customized alternative instead of a uniform mass-produced product shall become a reality, then the cross-organizational efficiency must be kept at a competitive level. This is the real challenge for mass customization. A radical restructuring of both the internal and the external knowledge management systems...

  16. Quasilocal mass in general relativity.

    Science.gov (United States)

    Wang, Mu-Tao; Yau, Shing-Tung

    2009-01-16

    There have been many attempts to define the notion of quasilocal mass for a spacelike two surface in spacetime by the Hamilton-Jacobi analysis. The essential difficulty in this approach is to identify the right choice of the background configuration to be subtracted from the physical Hamiltonian. Quasilocal mass should be non-negative for surfaces in general spacetime and zero for surfaces in flat spacetime. In this Letter, we propose a new definition of gauge-independent quasilocal mass and prove that it has the desired properties.

  17. Produção de forragem em pastagem de bermuda sobre-semeada com aveia e azevém Forage production on bermudagrass sod seeding with oat and ryegrass

    Directory of Open Access Journals (Sweden)

    Lilian Elgalise Techio Pereira

    2008-04-01

    Full Text Available O objetivo do presente estudo foi comparar dois sistemas forrageiros manejados com vacas da raça Holandesa. Os sistemas foram constituídos por pastagem de bermuda (Cynodon dactylon (L. Pers cv. "Coastcross" sobre-semeada com aveia preta (Avena strigosa Schreb. cv. "Comum" e azevém (Lolium multiflorum Lam. cv. "Comum" e aveia e azevém em cultivo estreme. Foram conduzidos oito pastejos (de 09/06/04 a 13/10/04 e de 02/08/05 a 29/10/05, sendo avaliada a massa de forragem pré e pós-pastejo, a taxa de acúmulo diário de matéria seca (MS, a produção total de forragem, a oferta de forragem, a composição botânica, a biomassa total de lâminas foliares e carga animal. Não foram observadas diferenças significativas (P>0,05 para os referidos parâmetros. A produção total de MS, a taxa de acúmulo diário de MS e a carga animal foram de 8467,9; 7105,7kg de MS ha-1; 54,1 e 69,2kg de MS ha-1 dia-1; 1050,8 e 925,5kg de peso vivo ha-1, para a pastagem de bermuda sobre-semeada com aveia e azevém e para a pastagem anual, respectivamente. Houve maior participação de lâminas foliares de aveia na pastagem constituída por aveia e azevém (P0,05 entre os sistemas forrageiros quanto à produção total de biomassa de lâminas foliares. Estes resultados indicam que o sistema forrageiro constituído por bermuda sobre-semeada com aveia e azevém, utilizada no período hibernal, pode ser usada em condições climáticas similares às do presente estudo.This study was aimed at comparing two pasture-based systems grazed by Holstein cows. The systems were sod seeding of black oat (Avena strigosa Schreb. cv. Common and ryegrass (Lolium multiflorum Lam. cv. Common in bermudagrass (Cynodon dactylon (L. Pers cv. Coastcross and oat and ryegrass mixture in extreme cultivation. From 06/09/04 to 10/13/04 and 08/02/05 to 10/29/05, in eight grazing periods, the pregraze and postgraze herbage mass, dry matter (DM daily acumulation rate, total dry matter production

  18. Koide's Mass Formula for Neutrinos

    Science.gov (United States)

    Brannen, Carl

    2006-05-01

    We derive Koide's mass formula as an eigenvector equation. We show that to within current experimental error, the square roots of the masses of the charged leptons follow the simple equation (m^-n)^0.5 = μ1(1 + √2(δ1+ 2nπ/3)) where δ1 is the interesting number .22222204717(48) and μ1 is a constant. Next we generalize the Koide formula to the neutrinos by assuming that the square root of the mass of the smallest neutrino must be taken to be negative. Then masses of the simple form (m^0n)^0.5 = μ0(1 + √2(δ1+ π/12 + 2nπ/3)) where 3;μ0= 3^12 ;μ1, satisfy recent neutrino oscillation measurements close to the centers of the error bars. Finally, we discuss the preon model for the fermions that led to the above discovery.

  19. A Propellant Mass Gauge Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Technologies Group, Inc. proposes the development of a Liquid-Oxygen Mass Gauge, (LMG) for In-Space cryogenic storage capable of continuous monitoring of...

  20. Children and the Mass Media

    Science.gov (United States)

    Winston, Shirley

    1970-01-01

    Resume of testimony given at hearings at the White House Conference on Children, September, 1970. Topics considered were the influence of the mass media on children and ways to improve media products. (NH)

  1. Mass Media and Political Participation

    Science.gov (United States)

    Lewellen, James R.

    1976-01-01

    Research reviews and statistical analysis of a specific study suggest that the mass media play a direct role in the political socialization of adolescents insofar as overt political behavior is concerned. (Author/AV)

  2. Electromagnetic contributions to pseudoscalar masses

    CERN Document Server

    Basak, S; Bernard, C; DeTar, C; Freeland, E; Freeman, W; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M; Osborn, J; Sugar, R L; Torok, A; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to "Dashen's theorem." This in turn will allow us to significantly reduce the systematic errors in our determination of m_u/m_d.

  3. Mass transfer between binary stars

    Science.gov (United States)

    Modisette, J. L.; Kondo, Y.

    1980-01-01

    The transfer of mass from one component of a binary system to another by mass ejection is analyzed through a stellar wind mechanism, using a model which integrates the equations of motion, including the energy equation, with an initial static atmosphere and various temperature fluctuations imposed at the base of the star's corona. The model is applied to several situations and the energy flow is calculated along the line of centers between the two binary components, in the rotating frame of the system, thereby incorporating the centrifugal force. It is shown that relatively small disturbances in the lower chromosphere or photosphere can produce mass loss through a stellar wind mechanism, due to the amplification of the disturbance propagating into the thinner atmosphere. Since there are many possible sources of the disturbance, the model can be used to explain many mass ejection phenomena.

  4. Functional genomics by mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Mann, M

    2000-01-01

    Systematic analysis of the function of genes can take place at the oligonucleotide or protein level. The latter has the advantage of being closest to function, since it is proteins that perform most of the reactions necessary for the cell. For most protein based ('proteomic') approaches to gene...... function, mass spectrometry is the method of choice. Mass spectrometry can now identify proteins with very high sensitivity and medium to high throughput. New instrumentation for the analysis of the proteome has been developed including a MALDI hybrid quadrupole time of flight instrument which combines...... numbers of intact proteins by mass spectrometry directly. Examples from this laboratory illustrate biological problem solving by modern mass spectrometric techniques. These include the analysis of the structure and function of the nucleolus and the analysis of signaling complexes....

  5. Mass-sensitive chemical preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Adkins, Douglas R.; Lewis, Patrick R.

    2007-01-30

    A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  6. Cryoablation for Small Renal Masses

    Directory of Open Access Journals (Sweden)

    J. L. Dominguez-Escrig

    2008-01-01

    Full Text Available Advances in imaging techniques (CT and MRI and widespread use of imaging especially ultrasound scanning have resulted in a dramatic increase in the detection of small renal masses. While open partial nephrectomy is still the reference standard for the management of these small renal masses, its associated morbidity has encouraged clinicians to exploit the advancements in minimally invasive ablative techniques. The last decade has seen the rapid development of laparoscopic partial nephrectomy and novel ablative techniques such as, radiofrequency ablation (RFA, high-intensity focused ultrasound (HIFU, and cryoablation (CA. In particular, CA for small renal masses has gained popularity as it combines nephron-sparing surgery with a minimally invasive approach. Studies with up to 5-year followup have shown an overall and cancer-specific 5-year survival of 82% and 100%, respectively. This manuscript will focus on the principles and clinical applications of cryoablation of small renal masses, with detailed review of relevant literature.

  7. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  8. Fragmentation and Dijet Mass Resolution

    CERN Document Server

    Green, D

    2004-01-01

    At the LHC the overlap of minimum bias events and the jet energy deposits in a calorimeter causes a degradation in the dijet mass resolution. Guided by QCD, a judicious set of cuts can be developed to mitigate this degradation.

  9. Mass Spectrometry of Halopyrazolium Salts

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Pande, U. C.;

    1983-01-01

    Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry. Dealkylation was found to be the predominant thermal decomposition. An exchange between covalent and ionic halogen prior...

  10. The Politics of Mass Digitization

    DEFF Research Database (Denmark)

    Thylstrup, Nanna Bonde

    Mass-digitization of cultural-heritage archives has become increasingly pervasive. From Google Books to Europeana, bounded material is converted into ephemeral data on an unprecedented scale, promising to provide mankind with readily accessible and enduring reservoirs of knowledge. Interrogating...... this phenomenon, this dissertation asks how mass digitization affects the politics of cultural heritage. Its central argument is that mass digitization of cultural heritage is neither a neutral technical process, nor a transposition of the politics of analog cultural heritage to the digital realm on a 1:1 scale....... Rather, it should be understood as distinct subpolitical processes that bring together a multiplicity of interests and actors hitherto foreign to the field of cultural heritage archives. Mass digitization is thus upheaving the disciplinary enclosures of cultural heritage and gives rise to new territorial...

  11. Food Mass Reduction Trade Study

    Science.gov (United States)

    Perchonok, Michele H.; Stoklosa, Adam M.

    2009-01-01

    Future long duration manned space flights beyond low earth orbit will require the food system to remain safe, acceptable, and nutritious while efficiently balancing appropriate vehicle resources such as mass, volume, power, water, and crewtime. Often, this presents a challenge since maintaining the quality of the food system can result in a higher mass and volume. The Orion vehicle is significantly smaller than the Shuttle vehicle and the International Space Station and the mass and volume available for food is limited. Therefore, the food team has been challenged to reduce the mass of the packaged food from 1.82 kg per person per day to 1.14 kg per person per day. Past work has concentrated on how to reduce the mass of the packaging which contributes to about 15% of the total mass of the packaged food system. Designers have also focused on integrating and optimizing the Orion galley equipment as a system to reduce mass. To date, there has not been a significant effort to determine how to reduce the food itself. The objective of this project is to determine how the mass and volume of the packaged food can be reduced while maintaining caloric and hydration requirements. The following tasks are the key elements to this project: (1) Conduct further analysis of the ISS Standard Menu to determine moisture, protein, carbohydrate, and fat levels. (2) Conduct trade studies to determine how to bring the mass of the food system down. Trade studies may include removing the water of the total food system and/or increasing the fat content. (3) Determine the preferred method for delivery of the new food (e.g. bars, or beverages) and the degree of replacement. (4) Determine whether there are commercially available products that meet the requirements. By the end of this study, an estimate of the mass and volume savings will be provided to the Constellation Program. In addition, if new technologies need to be developed to achieve the mass savings, the technologies, timeline, and

  12. Ambulance need at mass gatherings.

    Science.gov (United States)

    Meites, Elissa; Brown, John F

    2010-01-01

    Scant evidence exists to guide policy-making around public health needs during mass gatherings. In 2006, the City and County of San Francisco began requiring standby ambulances at all mass gatherings with attendance of >15,500 people. The objectives were to evaluate needs for ambulances at mass gatherings, and to make evidence-based recommendations for public health policy-makers. The hypothesis was that the needs for ambulances at mass gatherings can be estimated using community baseline data. Emergency medical services plans were reviewed for all public events with an anticipated attendance of >1,000 people in San Francisco County during the 12-month period 01 August 2006 through 31 July 2007. Ambulance transport data were confirmed by event coordinators and ambulance company records, and the rate was calculated by dividing ambulance transports by event attendance. Baseline ambulance transport rate was calculated by dividing the annual ambulance transports in the county's computer-aided dispatch system by the census population estimate. The risk ratio was calculated using the risk of transport from a mass gathering compared with the baseline risk of ambulance transport for the local community. Significance testing and confidence intervals were calculated. Descriptive information was available for 100% of events and ambulance transport data available for 97% of events. The majority of the mass gatherings (47 unique events; 59 event days) were outdoor, weekend festivals, parades, or concerts, though a large proportion were athletic events. The ambulance transport rate from mass gatherings was 1 per 59,000 people every six hours. Baseline ambulance transport rate in San Francisco was 1 per 20,000 people every six hours. The transport rate from mass gatherings was significantly lower than the community baseline (risk ratio [RR]=0.15, 95% CI=0.10-0.22, pambulance, 46% of ambulances were unused. San Francisco mass gatherings appear to present a lower risk of ambulance

  13. The Sixth Great Mass Extinction

    Science.gov (United States)

    Wagler, Ron

    2012-01-01

    Five past great mass extinctions have occurred during Earth's history. Humanity is currently in the midst of a sixth, human-induced great mass extinction of plant and animal life (e.g., Alroy 2008; Jackson 2008; Lewis 2006; McDaniel and Borton 2002; Rockstrom et al. 2009; Rohr et al. 2008; Steffen, Crutzen, and McNeill 2007; Thomas et al. 2004;…

  14. Parity violation and neutrino mass

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Besides the fact of parity violation in weak interactions, based on evidences from neutrino oscillation and tritium beta decay, a natural conjecture is hat neutrinos may be spacelike particles with a tiny proper mass. A Dirac-type equation for spacelike neutrinos is further investigated and its solutions are discussed. This equation can be written in two spinor equations coupled together via nonzero proper mass while respecting maximum parity violation.

  15. Radiative origin of neutrino masses

    CERN Document Server

    Aristizabal Sierra, D

    2015-01-01

    Mechanisms for Majorana neutrino mass generation can be classified according to the level at which the Weinberg operator is generated. The different possibilities can be sorted in "canonical" tree level and loop-induced realizations, the latter being motivated by their potential experimental testability. Here we discuss the one- and two-loop cases, paying special attention to systematic classification schemes which aim at building a full picture of neutrino mass generation.

  16. Neutrino Masses and Flavor Oscillations

    Science.gov (United States)

    Wang, Yifang; Xing, Zhi-Zhong

    2016-10-01

    This essay is intended to provide a brief description of the peculiar properties of neutrinos within and beyond the standard theory of weak interactions. The focus is on the flavor oscillations of massive neutrinos, from which one has achieved some striking knowledge about their mass spectrum and flavor mixing pattern. The experimental prospects towards probing the absolute neutrino mass scale, possible Majorana nature and CP-violating effects, will also be addressed.

  17. Higgs mass in noncommutative geometry

    Energy Technology Data Exchange (ETDEWEB)

    Devastato, A.; Martinetti, P. [Dipartimento di Fisica, Universita di Napoli Federico II, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Via Cintia, 80126 Napoli (Italy); Lizzi, F. [Dipartimento di Fisica, Universita di Napoli Federico II, Via Cintia, 80126 Napoli (Italy); INFN, Sezione di Napoli, Via Cintia, 80126 Napoli (Italy); Departament de Estructura i Constituents de la Materia, Universitat de Barcelona, Marti y Franques, Barcelona, Catalonia (Spain)

    2014-09-11

    In the noncommutative geometry approach to the standard model, an extra scalar field σ - initially suggested by particle physicist to stabilize the electroweak vacuum - makes the computation of the Higgs mass compatible with the 126 GeV experimental value. We give a brief account on how to generate this field from the Majorana mass of the neutrino, following the principles of noncommutative geometry. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Neutrino Mass and Flavour Models

    CERN Document Server

    King, Stephen F

    2009-01-01

    We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and unification, and show how such models can also solve the SUSY flavour and CP problems. We also discuss the theoretical implications of the measurement of a non-zero reactor angle, as hinted at by recent experimental measurements.

  19. Pulsation, Mass Loss and the Upper Mass Limit

    Science.gov (United States)

    Klapp, J.; Corona-Galindo, M. G.

    1990-11-01

    RESUMEN. La existencia de estrellas con masas en exceso de 100 M0 ha sido cuestionada por mucho tiempo. Lfmites superiores para la masa de 100 M0 han sido obtenidos de teorfas de pulsaci6n y formaci6n estelar. En este trabajo nosotros primero investigamos la estabilidad radial de estrellas masivas utilizando la aproximaci6n clasica cuasiadiabatica de Ledoux, la aproximaci6n cuasiadiabatica de Castor y un calculo completamente no-adiabatico. Hemos encontrado que los tres metodos de calculo dan resultados similares siempre y cuando una pequefia regi6n de las capas externas de la estrella sea despreciada para la aproximaci6n clasica. La masa crftica para estabilidad de estrellas masivas ha sido encontrada en acuerdo a trabajos anteriores. Explicamos Ia discrepancia entre este y trabajos anteriores por uno de los autores. Discunmos calculos no-lineales y perdida de masa con respecto a) lfmite superior de masa. The existence of stars with masses in excess of 100 M0 has been questioned for a very long time. Upper mass limits of 100 Me have been obtained from pulsation and star formation theories. In this work we first investigate the radial stability of massive stars using the classical Ledoux's quasiadiabatic approximation. the Castor quasiadiabatic approximation and a fully nonadiabatic calculation. We have found that the three methods of calculation give similar results provided that a small region in outer layers of the star be neglected for the classical approximation. The critical mass for stability of massive stars is found to be in agreement with previous work. We explain the reason for the discrepancy between this and previous work by one of the authors. We discuss non-linear calculations and mass loss with regard to the upper mass limit. Key words: STARS-MASS FUNCTION - STARS-MASS LOSS - STARS-PULSATION

  20. Wide-band mass measurements with a multi-reflection time-of-flight mass spectrograph

    CERN Document Server

    Schury, P; Wada, M; Wollnik, H

    2013-01-01

    We characterize the mass bandwidth of the a multi-reflection time-of-flight mass spectrograph, showing both the functional and useful mass bandwidth. We then demonstrate the use of a multi-reflection time-of-flight mass spectrograph to perform mass measurements in mass bands much wider than the mass bandwidth.

  1. Mass Extinctions in Earth's History

    Science.gov (United States)

    Ward, P. D.

    2002-12-01

    Mass extinctions are short intervals of elevated species death. Possible causes of Earth's mass extinctions are both external (astronomical) and internal (tectonic and biotic changes from planetary mechanisms). Paleontologists have identified five "major" mass extinctions (>50 die-off in less than a million years) and more than 20 other minor events over the past 550 million years. Earlier major extinction events undoubtedly also occurred, but we have no fossil record; these were probably associated with, for example, the early heavy bombardment that cleared out the solar system, the advent of oxygen in the atmosphere, and various "snowball Earth" events. Mass extinctions are viewed as both destructive (species death ) and constructive, in that they allow evolutionary innovation in the wake of species disappearances. From an astrobiological perspective, mass extinctions must be considered as able both to reduce biodiversity and even potentially end life on any planet. Of the five major mass extinctions identified on Earth, only one (the Cretaceous/Tertiary event 65 million years ago that famously killed off the dinosaurs ) is unambiguously related to the impact of an asteroid or comet ( 10-km diameter). The Permian/Triassic (250 Myr ago) and Triassic/Jurassic (202 Myr ago) events are now the center of debate between those favoring impact and those suggesting large volume flooding by basaltic lavas. The final two events, Ordovician (440 Myr ago) and Devonian (370 Myr ago) have no accepted causal mechanisms.

  2. The Galaxy Cosmological Mass Function

    CERN Document Server

    Lopes, Amanda R; Ribeiro, Marcelo B; Stoeger, William R

    2014-01-01

    We study the galaxy cosmological mass function (GCMF) in a semi-empirical relativistic approach using observational data provided by galaxy redshift surveys. Starting from the theory of Ribeiro & Stoeger (2003, arXiv:astro-ph/0304094) between the mass-to-light ratio, the selection function obtained from the luminosity function (LF) data and the luminosity density, the average luminosity $L$ and the average galactic mass $\\mathcal{M}_g$ are computed in terms of the redshift. $\\mathcal{M}_g$ is also alternatively estimated by a method that uses the galaxy stellar mass function (GSMF). Comparison of these two forms of deriving the average galactic mass allows us to infer a possible bias introduced by the selection criteria of the survey. We used the FORS Deep Field galaxy survey sample of 5558 galaxies in the redshift range $0.5 < z < 5.0$ and its LF Schechter parameters in the B-band, as well as this sample's stellar mass-to-light ratio and its GSMF data. Assuming ${\\mathcal{M}_{g_0}} \\approx 10^{11} ...

  3. Nuclear Masses and Neutron Stars

    CERN Document Server

    Kreim, Susanne; Lunney, David; Schaffner-Bielich, Jürgen

    2013-01-01

    Precision mass spectrometry of neutron-rich nuclei is of great relevance for astrophysics. Masses of exotic nuclides impose constraints on models for the nuclear interaction and thus affect the description of the equation of state of nuclear matter, which can be extended to describe neutron-star matter. With knowledge of the masses of nuclides near shell closures, one can also derive the neutron-star crustal composition. The Penning-trap mass spectrometer ISOLTRAP at CERN-ISOLDE has recently achieved a breakthrough measuring the mass of 82Zn, which allowed constraining neutron-star crust composition to deeper layers (Wolf et al., PRL 110, 2013). We perform a more detailed study on the sequence of nuclei in the outer crust of neutron stars with input from different nuclear models to illustrate the sensitivity to masses and the robustness of neutron-star models. The dominant role of the N=50 and N=82 closed neutron shells for the crustal composition is confirmed.

  4. Virial mass in DGP cosmology

    CERN Document Server

    Shahidi, Shahab

    2012-01-01

    In this proposal we study the problem of the virial mass discrepancy in the context of DGP brane gravity. DGP model is a kind of brane-world model such that the corrections to the usual gravity occurred in the large distance limit relative to the distance scale of the model defined as a ratio of the brane Planck scale to the bulk Planck scale. The extra dimension of this model is noncompact. This model is composed with an Einstein-Hilbert action in 5 dimensions plus an induced 4D action guarantees the existence of gravity on the brane. The importance of this model is that it can explain the self-acceleration of our universe without use of any type of dark energy. The virial mass discrepancy is an important problem in cosmology and it can be explained by dark matter. This is due to our various ways in measurement of the mass of the galaxy clusters. One of the ways we can measure the mass of a cluster of galaxies is to measure the galaxy masses and then add them up to obtain the cluster mass. Another way is to ...

  5. Stellar Initial Mass Function: Trends With Galaxy Mass And Radius

    Science.gov (United States)

    Parikh, Taniya

    2017-06-01

    There is currently no consensus about the exact shape and, in particular, the universality of the stellar initial mass function (IMF). For massive galaxies, it has been found that near-infrared (NIR) absorption features, which are sensitive to the ratio of dwarf to giant stars, deviate from a Milky Way-like IMF; their modelling seems to require a larger fraction of low mass stars. There are now increasing results looking at whether the IMF varies not only with galaxy mass, but also radially within galaxies. The SDSS-IV/MaNGA integral-field survey will provide spatially resolved spectroscopy for 10,000 galaxies at R 2000 from 360-1000nm. Spectra of early-type galaxies were stacked to achieve high S/N which is particularly important for features in the NIR. Trends with galaxy radius and mass were compared to stellar population models for a range of absorption features in order to separate degeneracies due to changes in stellar population parameters, such as age, metallicity and element abundances, with potential changes in the IMF. Results for 611 galaxies show that we do not require an IMF steeper than Kroupa as a function of galaxy mass or radius based on the NaI index. The Wing-Ford band hints towards a steeper IMF at large radii however we do not have reliable measurements for the most massive galaxies.

  6. Methods for recalibration of mass spectrometry data

    Science.gov (United States)

    Tolmachev, Aleksey V.; Smith, Richard D.

    2009-03-03

    Disclosed are methods for recalibrating mass spectrometry data that provide improvement in both mass accuracy and precision by adjusting for experimental variance in parameters that have a substantial impact on mass measurement accuracy. Optimal coefficients are determined using correlated pairs of mass values compiled by matching sets of measured and putative mass values that minimize overall effective mass error and mass error spread. Coefficients are subsequently used to correct mass values for peaks detected in the measured dataset, providing recalibration thereof. Sub-ppm mass measurement accuracy has been demonstrated on a complex fungal proteome after recalibration, providing improved confidence for peptide identifications.

  7. ACTOMP - AUTOCAD TO MASS PROPERTIES

    Science.gov (United States)

    Jones, A.

    1994-01-01

    AutoCAD to Mass Properties was developed to facilitate quick mass properties calculations of structures having many simple elements in a complex configuration such as trusses or metal sheet containers. Calculating the mass properties of structures of this type can be a tedious and repetitive process, but ACTOMP helps automate the calculations. The structure can be modelled in AutoCAD or a compatible CAD system in a matter of minutes using the 3-Dimensional elements. This model provides all the geometric data necessary to make a mass properties calculation of the structure. ACTOMP reads the geometric data of a drawing from the Drawing Interchange File (DXF) used in AutoCAD. The geometric entities recognized by ACTOMP include POINTs, 3DLINEs, and 3DFACEs. ACTOMP requests mass, linear density, or area density of the elements for each layer, sums all the elements and calculates the total mass, center of mass (CM) and the mass moments of inertia (MOI). AutoCAD utilizes layers to define separate drawing planes. ACTOMP uses layers to differentiate between multiple types of similar elements. For example if a structure is made of various types of beams, modeled as 3DLINEs, each with a different linear density, the beams can be grouped by linear density and each group placed on a separate layer. The program will request the linear density of 3DLINEs for each new layer it finds as it processes the drawing information. The same is true with POINTs and 3DFACEs. By using layers this way a very complex model can be created. POINTs are used for point masses such as bolts, small machine parts, or small electronic boxes. 3DLINEs are used for beams, bars, rods, cables, and other similarly slender elements. 3DFACEs are used for planar elements. 3DFACEs may be created as 3 or 4 Point faces. Some examples of elements that might be modelled using 3DFACEs are plates, sheet metal, fabric, boxes, large diameter hollow cylinders and evenly distributed masses. ACTOMP was written in Microsoft

  8. ACTOMP - AUTOCAD TO MASS PROPERTIES

    Science.gov (United States)

    Jones, A.

    1994-01-01

    AutoCAD to Mass Properties was developed to facilitate quick mass properties calculations of structures having many simple elements in a complex configuration such as trusses or metal sheet containers. Calculating the mass properties of structures of this type can be a tedious and repetitive process, but ACTOMP helps automate the calculations. The structure can be modelled in AutoCAD or a compatible CAD system in a matter of minutes using the 3-Dimensional elements. This model provides all the geometric data necessary to make a mass properties calculation of the structure. ACTOMP reads the geometric data of a drawing from the Drawing Interchange File (DXF) used in AutoCAD. The geometric entities recognized by ACTOMP include POINTs, 3DLINEs, and 3DFACEs. ACTOMP requests mass, linear density, or area density of the elements for each layer, sums all the elements and calculates the total mass, center of mass (CM) and the mass moments of inertia (MOI). AutoCAD utilizes layers to define separate drawing planes. ACTOMP uses layers to differentiate between multiple types of similar elements. For example if a structure is made of various types of beams, modeled as 3DLINEs, each with a different linear density, the beams can be grouped by linear density and each group placed on a separate layer. The program will request the linear density of 3DLINEs for each new layer it finds as it processes the drawing information. The same is true with POINTs and 3DFACEs. By using layers this way a very complex model can be created. POINTs are used for point masses such as bolts, small machine parts, or small electronic boxes. 3DLINEs are used for beams, bars, rods, cables, and other similarly slender elements. 3DFACEs are used for planar elements. 3DFACEs may be created as 3 or 4 Point faces. Some examples of elements that might be modelled using 3DFACEs are plates, sheet metal, fabric, boxes, large diameter hollow cylinders and evenly distributed masses. ACTOMP was written in Microsoft

  9. Tuned mass absorber on a flexible structure

    DEFF Research Database (Denmark)

    Krenk, Steen; Høgsberg, Jan Becker

    2014-01-01

    The classic design of a tuned mass absorber is based on a simple two-mass analogy in which the tuned mass is connected to the structural mass with a spring and a viscous damper. In a flexible multi-degree-of-freedom structure the tuned mass absorber is typically introduced to provide damping of a...

  10. Precise top-quark mass from the diphoton mass spectrum

    CERN Document Server

    Kawabata, Sayaka

    2016-01-01

    We calculate the $gg\\to\\gamma\\gamma$ amplitude by including the $t\\bar t$ bound-state effects near their mass threshold. In terms of the non-relativistic expansion of the amplitude, the LO contribution is a constant (energy-independent) term in the one-loop amplitude. We include the NLO contribution described by the non-relativistic Green function and part of the NNLO contribution. Despite a missing NLO piece which can be accomplished with the two-loop-level amplitude via massive quarks, the shape of the diphoton mass spectrum is predicted with a good accuracy. Thanks to the simple and clean nature of the observable, its experimental measurement can be a superior method to determine the top-quark mass at hadron colliders.

  11. A mass spectrometry primer for mass spectrometry imaging.

    Science.gov (United States)

    Rubakhin, Stanislav S; Sweedler, Jonathan V

    2010-01-01

    Mass spectrometry imaging (MSI), a rapidly growing subfield of chemical imaging, employs mass spectrometry (MS) technologies to create single- and multi-dimensional localization maps for a variety of atoms and molecules. Complimentary to other imaging approaches, MSI provides high chemical specificity and broad analyte coverage. This powerful analytical toolset is capable of measuring the distribution of many classes of inorganics, metabolites, proteins, and pharmaceuticals in chemically and structurally complex biological specimens in vivo, in vitro, and in situ. The MSI approaches highlighted in this Methods in Molecular Biology volume provide flexibility of detection, characterization, and identification of multiple known and unknown analytes. The goal of this chapter is to introduce investigators who may be unfamiliar with MS to the basic principles of the mass spectrometric approaches as used in MSI. In addition to guidelines for choosing the most suitable MSI method for specific investigations, cross-references are provided to the chapters in this volume that describe the appropriate experimental protocols.

  12. CT findings of sternal masses

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Ik; Choi, Yo Won; Kim, Bong Soo; Jeon, Seok Chol; Seo, Hueng Seok; Hahm, Chang Kok; Park, Choong Ki; Joo, Kyung Bin [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-09-01

    To describe and characterize the CT findings of the sternal masses. We retrospectively reviewed the medical records, pathologic reports, and CT findings of 16 patients whose chest CT revealed sternal masses. Two primary tumors were found, namely chondrosarcomas. Twelve metastatic tumors had arisen were from lung cancer (n = 4), breast cancer (n = 3), hepatoma (n 2), osteosarcoma (n = 1), carotid body paraganglioma (n = 1), and immature sacrococcygeal teratoma (n = 1). Other were Castleman's disease (n = 1) and inflammatory pseudotumor (n = 1). Chondrosarcomas were large expansile osteolytic masses showing a variable degree of cortical breakthrough and containing punctuate chondroid calcifications. Most sternal metastases (83 %) were located in the manubrium and were accompanied by metastasis in other bones (83 %). Metastatic tumors were nonspecific osteolytic soft tissue masses showing homogeneous or inhomogeneous enhancement, except for those which arose from an osteosarcoma and a lung cancer, and showed osteoblastic lesions. Castleman's disease was seen as an ill-defined enhanced soft tissue mass involving the sternum and adjacent soft tissue. Inflammatory pseudotumor appeared as an infiltrating lesion around the sternoclavicular joint and was accompanied by sclerosis and the erosion of opposing sternal and clavicular ends. Most of the sternal masses are due to malignant neoplasms, among which metastatic tumors are more common than primary ones. Metastatic tumors affect the manubrium more commonly than the body portion, and most also affect other bones in the thorax. CT findings of metastatic tumors are non-specific and thus do not suggest their origin. Non-neoplastic masses are not readily differentiated from malignant tumors on the basis of CT findings alone and require pathological confirmation.

  13. Simultaneous mass detection for direct inlet mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, R.L.

    1979-05-01

    The evolution of analytical techniques for application in trace analysis has led to interest in practical methods for real-time monitoring. Direct inlet mass spectrometry (DIMS) has been the subject of considerable activity in recent years. A DIMS instrument is described which consists of an inlet system designed to permit particles entrained in the inlet air stream to strike a hot, oxidized rhenium filament which serves as a surface ionization source. A mass analyzer and detection system then permits identification of the elemental composition of particulates which strike the filament.

  14. Triple Pulsar Tests Mass Triplets

    CERN Document Server

    Shao, Lijing

    2016-01-01

    Three conceptually different masses appear in equations of motion for objects under gravity, namely, inertial mass, $m_{\\cal I}$, passive gravitational mass, $m_{\\cal P}$, and active gravitational mass, $m_{\\cal A}$. It is assumed that, for any objects, $m_{\\cal I} = m_{\\cal P} = m_{\\cal A}$ in Newtonian gravity, and $m_{\\cal I} = m_{\\cal P}$ in Einsteinian gravity, oblivious to objects' sophisticated internal structure. Empirical examination of the equivalence probes deep into gravity theories. We propose new tests based on pulsar timing of the stellar triple system, PSR J0337+1715. Various machine-precision three-body simulations are performed, from which, equivalence-violating parameters are extracted with Markov chain Monte Carlo sampling that takes full correlations into account. We show that the difference in masses can be probed to $3\\times10^{-8}$, improving the post-Newtonian constraints of strong equivalence principle by $10^3$--$10^6$. The test of $m_{\\cal P}=m_{\\cal A}$ presents the first test of ...

  15. Current Direct Neutrino Mass Experiments

    CERN Document Server

    Drexlin, G; Mertens, S; Weinheimer, C

    2013-01-01

    In this contribution we review the status and perspectives of direct neutrino mass experiments. These experiments investigate the kinematics of $\\beta$-decays of specific isotopes ($^3$H, $^{187}$Re, $^{163}$Ho) to derive model-independent information on the averaged electron (anti-) neutrino mass, which is formed by the incoherent sum of the neutrino mass eigenstates contributing to the electron neutrino. We first review the kinematics of $\\beta$-decay and the determination of the neutrino mass, before giving a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for $^3$H, cryo-bolometers for $^{187}$Re). We then describe the Karlsruhe Tritium Neutrino (KATRIN) experiment which is currently under construction at Karlsruhe Institute of Technology. The large-scale setup will use the MAC-E-Filter principle pioneered earlier to push the sensitivity down to a value of 200 meV(90% C.L.). KATRIN faces many technological challenges that have to be resolved with regar...

  16. Photon and graviton mass limits

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

    2008-01-01

    We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

  17. Neutrino mass without cosmic variance

    CERN Document Server

    LoVerde, Marilena

    2016-01-01

    Measuring the absolute scale of the neutrino masses is one of the most exciting opportunities available with near-term cosmological datasets. Two quantities that are sensitive to neutrino mass, scale-dependent halo bias $b(k)$ and the linear growth parameter $f(k)$ inferred from redshift-space distortions, can be measured without cosmic variance. Unlike the amplitude of the matter power spectrum, which always has a finite error, the error on $b(k)$ and $f(k)$ continues to decrease as the number density of tracers increases. This paper presents forecasts for statistics of galaxy and lensing fields that are sensitive to neutrino mass via $b(k)$ and $f(k)$. The constraints on neutrino mass from the auto- and cross-power spectra of spectroscopic and photometric galaxy samples are weakened by scale-dependent bias unless a very high density of tracers is available. In the high density limit, using multiple tracers allows cosmic-variance to be beaten and the forecasted errors on neutrino mass shrink dramatically. In...

  18. FOREWORD: Special issue on mass

    Science.gov (United States)

    Gläser, Michael

    2003-12-01

    This special issue is intended to present a review of mass standards, mass determination and the efforts to replace the international prototype of the kilogram by a new definition of the kilogram based on a fundamental constant of physics. Mass is a quantity that is familiar to everybody primarily for its importance in commerce. It is not only one of the traditional quantities of metrology but also of science in general. The unit of mass has always been based on a material object and, since 1889, on the international prototype of the kilogram. The mass of any standard weight is derived from this prototype by a cascade of comparison measurements using balances. The sources of uncertainty of the mass of a standard depend upon the circumstances of the weighing process and the long-term instabilities of the intermediate standards. The international prototype—its mass is one kilogram by definition—may also suffer from instabilities or drifts in time, but until now it has not been possible to check this by comparison with a fundamental constant in physics. Repeated verifications of some 40 or so national prototypes of the members of the Metre Convention have shown significant drifts with an average of about 50 µg within 100 years, a fact that casts doubt on the stability of the international prototype itself. Experiments have been underway for about 30 years on linking fundamental constants such as the Avogadro constant or, correspondingly, the atomic mass unit and Planck's constant to the kilogram. Relative uncertainties of the order of 10-7 have been reached today, still one order of magnitude too large for monitoring the stability of the international prototype or for a new definition. The first article of this special issue gives information on the international and the national prototypes of the kilogram, its material, manufacture, cleaning procedures, stability investigations and the periodic verifications of national prototypes. The next article describes

  19. Galaxy And Mass Assembly (GAMA)

    CERN Document Server

    Driver, Simon P

    2008-01-01

    The GAMA survey aims to deliver 250,000 optical spectra (3--7Ang resolution) over 250 sq. degrees to spectroscopic limits of r_{AB} <19.8 and K_{AB}<17.0 mag. Complementary imaging will be provided by GALEX, VST, UKIRT, VISTA, HERSCHEL and ASKAP to comparable flux levels leading to a definitive multi-wavelength galaxy database. The data will be used to study all aspects of cosmic structures on 1kpc to 1Mpc scales spanning all environments and out to a redshift limit of z ~ 0.4. Key science drivers include the measurement of: the halo mass function via group velocity dispersions; the stellar, HI, and baryonic mass functions; galaxy component mass-size relations; the recent merger and star-formation rates by mass, types and environment. Detailed modeling of the spectra, broad SEDs, and spatial distributions should provide individual star formation histories, ages, bulge-disc decompositions and stellar bulge, stellar disc, dust disc, neutral HI gas and total dynamical masses for a significant subset of the...

  20. The Mass of the Cosmos

    CERN Document Server

    Hellaby, C

    2006-01-01

    We point out that the mass of the cosmos on gigaparsec scales can be measured, owing to the unique geometric role of the maximum in the areal radius. Unlike all other points on the past null cone, this maximum has an associated mass, which can be calculated with very few assumptions about the cosmological model, providing a measurable characteristic of our cosmos. In combination with luminosities and source counts, it gives the bulk mass to light ratio. The maximum is particularly sensitive to the values of the bulk cosmological parameters. In addition, it provides a key reference point in attempts to connect cosmic geometry with observations. We recommend the determination of the distance and redshift of this maximum be explicitly included in the scientific goals of the next generation of reshift surveys. The maximum in the redshift space density provides a secondary large scale characteristic of the cosmos.

  1. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  2. Slowly rotating homogeneous masses revisited

    CERN Document Server

    Reina, Borja

    2015-01-01

    Hartle's model for slowly rotating stars has been extensively used to compute equilibrium configurations of slowly rotating stars to second order in perturbation theory in General Relativity, given a barotropic equation of state (EOS). A recent study based on the modern theory of perturbed matchings show that the model must be amended to accommodate EOS's in which the energy density does not vanish at the surface of the non rotating star. In particular, the expression for the change in mass given in the original model, i.e. a contribution to the mass that arises when the perturbations are chosen so that the pressure of the rotating and non rotating configurations agree, must be modified with an additional term. In this paper, the amended change in mass is calculated for the case of constant density stars.

  3. Coronal Mass Ejections An Introduction

    CERN Document Server

    Howard, Timothy

    2011-01-01

    In times of growing technological sophistication and of our dependence on electronic technology, we are all affected by space weather. In its most extreme form, space weather can disrupt communications, damage and destroy spacecraft and power stations, and increase radiation exposure to astronauts and airline passengers. Major space weather events, called geomagnetic storms, are large disruptions in the Earth’s magnetic field brought about by the arrival of enormous magnetized plasma clouds from the Sun. Coronal mass ejections (CMEs) contain billions of tons of plasma and hurtle through space at speeds of several million miles per hour. Understanding coronal mass ejections and their impact on the Earth is of great interest to both the scientific and technological communities. This book provides an introduction to coronal mass ejections, including a history of their observation and scientific revelations, instruments and theory behind their detection and measurement, and the status quo of theories describing...

  4. Protein Analysis by Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Cindic, M.

    2008-04-01

    Full Text Available Soft ionization techniques, electrospray (ESI and matrix-assisted laser desorption/ionization (MALDI make the analysis of biomolecules by mass spectrometry (MS possible. MS is used for determination of the molecular weight of peptides and protein, sequence analysis, characterization of protein-ligand interactions etc. The detection limit, resolution and mass accuracy depend on instrument used (Table 1. Impurities (buffers, salts, detergents can reduce the ion intensities or even totally suppress them, so a separation method (chromatography, 2D-gel electrophoresis must be used for purification of the sample.Molecular mass of intact protein can be determined by ESI or MALDI MS. Multiply charged ions are produced by ESI MS, while singly charged ions are predominant in MALDI spectra (Fig. 2.Sequence analysis of proteins by MS can be performed using peptide mass fingerprint. In this method, proteins are separated by 2-D gel electrophoresis and digested with specific protease (Table 2 or digested and then separated by two-dimensional chromatography (Fig. 1. The obtained peptide mixtures are analyzed by MS or MALDI-TOF technique. The masses determined by MS are compared with calculated masses from database entries. Different algorithms have been developed for protein identification. Example of posttranslational modifications (N- and O-glycosylation and protein sequence complex analysis after dual digestion (endoproteinase digestion followed by endoglycosidase digestion is shown in Fig. 3.It is known that detection of peptides by MS is influenced by intrinsic properties like amino acid composition, the basicity of the C-terminal amino acid, hydrophobicity, etc. Arginine-containing peptides dominate in MS spectra of tryptic digest, so the chemical derivatization of lysine terminal residue by O-methilisourea or 2-methoxy-4,5-1H-imidazole was suggested (Fig. 4.The peptide mass fingerprint method can be improved further by peptide fragmentation using tandem

  5. First mass measurements at LHCb

    CERN Multimedia

    Bressieux, J

    2011-01-01

    The LHC opens new frontiers in heavy flavour physics through an unprecedented statistical reach for a variety of interesting states produced in pp collisions. The LHCb spectrometer provides a good mass resolution and is suitable for spectroscopy studies. We present first preliminary mass measurements of several $b$ hadrons and of the exotic $X(3872)$ meson, reconstructed in final states containing a $J/\\psi$ using the data collected in 2010 by the LHCb experiment. An important aspect of the analysis is the calibration of the momentum scale using $J/\\psi \\to \\mu^+ \\mu^-$ decays, as well as the control of systematic uncertainties. While the already very competitive mass measurements for the $B^+$, $B^0$ and $B^0_s$ mesons receive similar contributions from systematic and statistical uncertainties, those of the $\\Lambda_b$, $B^+_c$ and $X(3872)$ particles are dominated by statistical uncertainties, and will therefore substantially improve with more data in the future.

  6. Gauge Trimming of Neutrino Masses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mu-Chun; /Fermilab /UC, Irvine; de Gouvea, Andre; /Northwestern U. /Fermilab; Dobrescu, Bogdan A.; /Fermilab

    2006-12-01

    We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ''right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in terms of four rational parameters. This generalization of the B-L symmetry with generation-dependent lepton charges leads to neutrino masses induced by operators of high dimensionality. Neutrino masses are thus naturally small without invoking physics at energies above the TeV scale, whether neutrinos are Majorana or Dirac fermions. This ''Leptocratic'' Model predicts the existence of light quasi-sterile neutrinos with consequences for cosmology, and implies that collider experiments may reveal the origin of neutrino masses.

  7. The KATRIN Neutrino Mass Experiment

    Science.gov (United States)

    Parno, Diana; Katrin Collaboration

    2017-01-01

    While neutrino oscillation experiments have demonstrated that the particles have non-zero mass, the absolute neutrino mass scale is still unknown. The Karlsruhe Tritium Neutrino experiment (KATRIN) is designed to improve on previous laboratory limits by an order of magnitude, probing the effective neutrino mass with a sensitivity approaching 0.2 eV at 90% confidence via the kinematics of tritium beta decay. At the same time, KATRIN has the potential to scan for sterile neutrinos at eV and keV scales. After years of preparation, all major components are now on site and commissioning is underway. I will report on the current status of the experiment, including recent results and preparations for the introduction of tritium later this year. US participation in KATRIN is supported by the U.S. Department of Energy Office of Science, Office of Nuclear Physics under Award Number DE-FG02-97ER41020.

  8. Inertial mass from Unruh temperatures

    Science.gov (United States)

    Giné, J.; McCulloch, M. E.

    2016-05-01

    It has been proposed that inertia can be explained as follows: when objects accelerate in one direction, a Rindler horizon forms in the other direction suppressing Unruh radiation on that side and producing a net Unruh radiation pressure that always opposes the acceleration, just like inertia. So far, this model has predicted masses over twice those expected. In this paper, an error in this model is corrected so that its prediction improves to within 29% of the expected Planck mass. It is also shown that inertial mass may be understood qualitatively by applying Carnot’s principle and entropy to Unruh temperatures, so that the work needed for inertia comes from the difference in the Unruh temperatures seen by the accelerated object and the cosmos. This implies that highly-accelerated systems may emit heat in a new way.

  9. Neutrino masses from new generations

    CERN Document Server

    Aparici, Alberto; Rius, Nuria; Santamaria, Arcadi

    2011-01-01

    We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, $\\mu - e$ conversion in nuclei and $\\mu \\rightarrow e \\gamma$ experiments. We also discuss the detection prospects at LHC.

  10. Neutrino mass from triton decay

    Science.gov (United States)

    Weinheimer, Christian

    2006-07-01

    Since the discovery of neutrino flavor oscillation in different fields and by many different experiments we believe that neutrinos have non-vanishing masses in contrast to their current description within the Standard Model of particle physics. However, the absolute values of the neutrino masses, which are as important for particle physics as they are for cosmology and astrophysics, cannot be determined by oscillation experiments alone. There are a few ways to determine the neutrino mass scale, but the only model-independent method is the investigation of the electron energy spectrum of a β decay near its endpoint with tritium being the ideal isotope for the classical spectrometer set-up. The tritium β decay experiments at Mainz and Troitsk have recently been finished. At Mainz all relevant systematic uncertainties have been investigated by dedicated experiments yielding an upper limit of m(ν)MAC-E-Filter type. The recent achievements in test experiments show, that this very challenging experiment is feasible.

  11. MASS CUSTOMIZATION and PRODUCT MODELS

    DEFF Research Database (Denmark)

    Svensson, Carsten; Malis, Martin

    2003-01-01

    to the product. Through the application of a mass customization strategy, companies have a unique opportunity to create increased customer satisfaction. In a customized production, knowledge and information have to be easily accessible since every product is a unique combination of information. If the dream...... of a customized alternative instead of a uniform mass-produced product shall become a reality, then the cross-organizational efficiency must be kept at a competitive level. This is the real challenge for mass customization. A radical restructuring of both the internal and the external knowledge management systems......When dealing with complex product models, efficient knowledge distribution is essential to obtain success. This paper describes how product models can be applied to support the knowledge distribution. The change towards individualization will radically affect the knowledge application in relation...

  12. Electrophoresis-mass spectrometry probe

    Science.gov (United States)

    Andresen, Brian D.; Fought, Eric R.

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

  13. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    CERN Document Server

    Smith, Donald F; Leach, Franklin E; Robinson, Errol W; Paša-Tolić, Ljiljana; Heeren, Ron M A

    2013-01-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the sub-micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for elemental formula assignment based on exact mass measurement. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissu...

  14. Herbage productivity, chemical composition and persistence of introduced grass cultivars in mountain area

    Directory of Open Access Journals (Sweden)

    Josip Leto

    2006-07-01

    Full Text Available The seeds for grassland establishment and renovation have been mostly imported into the Republic of Croatia. The aim of the present research was to determine yield, chemical composition and persistence of 13 introduced grass cultivars (cv. in the hilly mountain area of Croatia. The Lolium perenne cv. Pimpernel and Calibra, and Phleum pratense cv. Richmond had the highest dry matter (DM yield in the year 2000 (10,5 t/ha in average. Phalaris arundinacea had the lowest DM yield (6,35 t/ha but not statistically lower than Bromus inermis, Festuca rubra, and all three Dactylis glomerata cultivars, Lolium westerwoldicum and Phleum pratense cv. Bilbo (7,12 t/ha in average. The highest DM yields determined in the year 2001 were obtained from Festuca rubra, Phalaris arundinacea, Bromus inermis, Festuca pratensis, Dactylis glomerata cv. Okay, cv. Baraula, cv. Amba, Lolium perenne cv. Pimpernel, (14,9 t/ha in average. The lowest DM yield had Lolium westerwoldicum and Lolium multiflorum (9,8 t/ha in average. Phalaris arundinacea had the highest DM yield (12,89 t/ha in 2002. followed by Bromus inermis and Dactylis glomerata cultivars with 20% lower DM yield than Phalaris arundinacea, and Lolium westerwoldicum and Phleum pratense cv. Bilbo which had 24% lower DM yield, while both Lolium perenne cultivars had about 30% lower DM yield in comparison with Phalaris arundinacea. Significant differences (P<0.05 were observed between cultivars for all the chemical parameters investigated except fort nitrogen free extract (NFE. The highest crude protein (CP concentration was observed in Bromus inermis, Lolium multiflorum cv. Bofur, Dactylis glomerata cultivars, Phalaris arundinacea, Festuca pratensis, Lolium westerwoldicum, Phleum pratense cv. Bilbo (24,78% in average. Significantly the lowest crude fibre (CF was determined in Lolium westerwoldicum (18,07%, Festuca pratensis, Lolium multiflorum and Phalaris arundinacea (19,7% in average. The highest ground cover and the lowest variations over the investigation period were determined for Lolium perenne cv. Pimpernel, both Phleum pratense cultivars and Dactylis glomerata cv. Amba and Okay.

  15. Forms of potassium and sodium in some species of grasses and herbage

    Directory of Open Access Journals (Sweden)

    Grzegorz Nowak

    2013-12-01

    Full Text Available The forms of occurence of potassium and sodium were studied in the grasses Dactylis glomerata L., Poa annua L., Festuca rubra L. and dendelion (Taraxacum officinale Web. treated with increasing mineral fertilizer doses, magnesium and microelements, under conditions of pot culture. The plants took up potassium in amounts greatly exceeding their requirement, and sodium in very small amounts. Mineral NPK doses increased in the tested plants both the content of potassium and sodium forms soluble in trichloroacetic and acetic acids and water. Magnesium and microelements had no major influence on the content of these potassium forms, but they increased the concentration of analogous forms of sodium in Taraxacum officinale and did not influence their accumulation in the grasses. Potassium and sodium compounds were completely extracted from the plants with trichloroacetic, whereas acetic acid extracted 88-95 percent of potassium and 66-74 percent of sodium. Distilled water extracted 70-77 and 28-33 percent of potassium and sodium, respectively.

  16. Effect of cutting and frequency regimes on the herbage yield of Leucaena

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamurthy, K.; Munegowda, M.K.

    1982-01-01

    Leucaena (leucocephala) growing at Agricultural College Farm, Bangalore, was harvested at intervals of 40, 50, 60 and 70 days at height of 15, 75, and 150 cm above ground. Forage yield increased with both cutting interval and cutting height with an annual yield of 48.34 t/ha at 70-day interval and 150 cm stubble height. A cutting interval of 50-60 days at 75 cm height is recommended to obtain the optimum combination of succulent forage and nutrient content.

  17. Properties of herbage in relation to equine dysautonomia: biochemical composition and antioxidant and prooxidant actions.

    Science.gov (United States)

    McGorum, B C; Fry, S C; Wallace, G; Coenen, K; Robb, J; Williamson, G; Aruoma, O I

    2000-06-01

    To investigate the etiology of equine dysautonomia (ED), a degenerative polyneuropathy affecting grazing horses, the biochemical composition and antioxidant/prooxidant activities of aqueous extracts of plants collected from ED pastures were determined. Plants collected immediately after an outbreak of ED had reduced antioxidant and weak prooxidant activities when compared with control plants (plants collected from ED pastures out of ED season and control plants from ED pastures that were grown under favorable conditions). ED plants also had significantly increased concentrations of fructose and low molecular weight phenolic compounds, significantly more of one amino acid zone (probably valine), significantly less tartaric acid, and a nonsignificant decrease in ascorbic acid content when compared with control plants from ED pastures that were grown under favorable conditions. These findings suggest that ED plants may be under oxidative stress, possibly due to chilling, drought, or fungal colonization. However, experimental drought and chilling of plants did not reproduce the biochemical alterations identified in ED plants. It is possible that the altered biochemical content of ingested plants may contribute, directly or indirectly, to the development of ED in grazing horses.

  18. A validated method for gas chromatographic analysis of gamma-aminobutyric acid in tall fescue herbage

    Science.gov (United States)

    Gamma-Aminobutyric acid (GABA) is an inhibitory neurotransmitter in animals that is also found in plants and has been associated with plant responses to stress. A simple and relatively rapid method of GABA separation and quantification was developed from a commercially available kit for serum amino...

  19. Effects of Intra-Row Spacing on Herbage Yields of Two Groundnut ...

    African Journals Online (AJOL)

    SH

    Department of Crop Science, Faculty of Agriculture, Usmanu Danfodiyo University, Sokoto. ... Field experiments were conducted during 2009 and 2010 rainy seasons at the Dry Land Teaching and Research ... animals are reared on improved pastures; ... construction, the seeds are small and round .... A Project submitted to.

  20. Grazed grass herbage intake and performance of beef heifers with predetermined phenotypic residual feed intake classification

    National Research Council Canada - National Science Library

    Lawrence, P; Kenny, D A; Earley, B; McGee, M

    2012-01-01

    ... behaviour were measured for all heifers. Phenotypic residual feed intake (RFI) was calculated for each animal as the difference between actual DMI and expected DMI during the indoor winter period...

  1. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging

    NARCIS (Netherlands)

    Kiss, A.; Smith, D.F.; Jungmann, JH; Heeren, R.M.A.

    2013-01-01

    RATIONALE: Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with

  2. Quark mass and the masses of Goldstone bosons

    Institute of Scientific and Technical Information of China (English)

    Qing WU; Li-juan ZHOU; Wei-xing MA

    2008-01-01

    Based on the Dyson-Schwinger Equations (DSEs) of QCD in the "rainbow" approximation, the fully dressed quark propagator S,f (p) is investigated, and then an algebraic parametrization form of the propagator is obtained as a solu-tion of the equations. The dressed quark amplitudes A,f and Bf which built up the fully dressed quark propagator, and the dynamical running masses M,f, which is defined by A,f and By for light quarks u, d and s, are calculated, respec-tively. Using the predicted current masses m,f, quark local vacuum condensates, and our predicted value of pion decay constant, the masses of Goldstone bosons K, π and η and their in-medium values are also evaluated. Our predictions fit to data and to many other different calculations quite well. The numerical results show that the mass of quark is depen-dent of its momentum p'2. The fully dressed quark amplitudes A,f and B,f have correct behaviors and can be used for many purposes in our future researches on non-perturbative QCD.

  3. Boundaries of mass resolution in native mass spectrometry

    NARCIS (Netherlands)

    Lössl, Philip; Snijder, Joost; Heck, Albert J R

    2014-01-01

    Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)-protein interactions, to nanomachineries such as the proteasome and ribosome, to even viru

  4. Initial mass function of intermediate mass black hole seeds

    CERN Document Server

    Ferrara, A; Yue, B; Schleicher, D R G

    2014-01-01

    We study the Initial Mass Function (IMF) and host halo properties of Intermediate Mass Black Holes (IMBH, 10^{4-6} Msun) formed inside metal-free, UV illuminated atomic cooling haloes (virial temperature T_vir > 10^4 K) either via the direct collapse of the gas or via an intermediate Super Massive Star (SMS) stage. We achieve this goal in three steps: (a) we derive the gas accretion rate for a proto-SMS to undergo General Relativity instability and produce a direct collapse black hole (DCBH) or to enter the ZAMS and later collapse into a IMBH; (b) we use merger-tree simulations to select atomic cooling halos in which either a DCBH or SMS can form and grow, accounting for metal enrichment and major mergers that halt the growth of the proto-SMS by gas fragmentation. We derive the properties of the host halos and the mass distribution of black holes at this stage, and dub it the "Birth Mass Function"; (c) we follow the further growth of the DCBH due to accretion of leftover gas in the parent halo and compute the...

  5. Mass movement in northeast Afghanistan

    Science.gov (United States)

    Shroder, John F.; Weihs, Brandon J.; Schettler, Megan Jensen

    Mass movements of nearly all types occur in Afghanistan but in the high relief, rugged Pamir and Hindu Kush mountains of northeastern Afghanistan, mass-movement threats to lives and property necessitated study to elucidate problems to development. Twenty-two different mass movements in bedrock in the Badakhshan Province of northeastern Afghanistan were studied for this paper, including large rock falls and rock slides, along with massive slope-failure complexes with many types and rates of movement. Where higher altitudes prevail in the region, ice-cemented and ice-cored rock glaciers are also common and overlie some of the other mass movements. Inasmuch as seismic energy sources in the Eastern Hindu Kush are maximal in southern Badakhshan, and relief, slope angles and precipitation all increase from west to east as well, the causes of the pervasive mass movement are plentiful enough, although direct cause and slope-failure effect are not known. Some weak sedimentary lithologies downfaulted into, or draped across crystalline rocks, also failed. Some intermixed tills also occur but are not easily differentiated, even with analysis on the ground. Using high resolution satellite imagery and digital elevation models, we assessed geomorphologic parameters to characterize spatial-organization structures related to zones of erosion, deposition and further hazard potential. Analyses indicate that many of the massive slope failures can be characterized and differentiated into various process domains and chronologic-development zones with their different impacts upon the landscape. Mass movements in Afghanistan can exhibit unique topographic signatures that can be used to better assess hazards in other mountain areas, especially where landslide-dam breakout floods threaten. Development of roads, bridges, buildings, and irrigation networks should be done with care in these regions of Afghanistan.

  6. Quadrupole Time-of-Flight Mass Spectrometer

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The system generates superior quality mass spectrometry (MS) and tandem mass spectrometry (MS/MS) data from both atmospheric pressure ionization (API) and...

  7. Binary stars: Mass transfer and chemical composition

    Science.gov (United States)

    Lambert, D. L.

    1982-01-01

    It is noted that mass exchange (and mass loss) within a binary system should produce observable changes in the surface chemical composition of both the mass losing and mass gaining stars as a stellar interior exposed to nucleosyntheses is uncovered. Three topics relating mass exchange and/or mass loss to nucleosynthesis are sketched: the chemical composition of Algol systems; the accretion disk of a cataclysmic variable fed by mass from a dwarf secondary star; and the hypothesis that classical Ba II giants result from mass transfer from a more evolved companion now present as a white dwarf.

  8. Mass spectrometry for biomarker development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chaochao; Liu, Tao; Baker, Erin Shammel; Rodland, Karin D.; Smith, Richard D.

    2015-06-19

    Biomarkers potentially play a crucial role in early disease diagnosis, prognosis and targeted therapy. In the past decade, mass spectrometry based proteomics has become increasingly important in biomarker development due to large advances in technology and associated methods. This chapter mainly focuses on the application of broad (e.g. shotgun) proteomics in biomarker discovery and the utility of targeted proteomics in biomarker verification and validation. A range of mass spectrometry methodologies are discussed emphasizing their efficacy in the different stages in biomarker development, with a particular emphasis on blood biomarker development.

  9. Leptogenesis. Theory and neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Buchmueller, W.

    2012-12-15

    After a brief discussion of baryon and lepton number nonconservation, we review the status of thermal leptogenesis with GUT scale neutrino masses, as well as low scale alternatives with keV neutrinos as dark matter and heavy neutrino masses within the reach of the LHC. Recent progress towards a full quantum mechanical description of leptogenesis is described with resonant leptogenesis as an application. Finally, cosmological B-L breaking after inflation is considered as origin of the hot early universe, generating entropy, baryon asymmetry and dark matter.

  10. Framework for reactive mass transport

    DEFF Research Database (Denmark)

    Jensen, Mads Mønster; Johannesson, Björn; Geiker, Mette Rica

    2014-01-01

    description is coupled to the system. The mass transport is solved by using the finite element method where the chemical equilibrium is solved explicitly by an operator splitting method. The IPHREEQC library is used as chemical equilibrium solver. The equation system, solved by IPHREEQC, is explained...... simulation, showing multi-species ingress with formation of new solid phases in the domain is described and calculated. It is shown that the numerical solution method is capable of solving the reactive mass transport system for the examples considered. (C) 2014 Elsevier B.V. All rights reserved....

  11. CARACTERÍSTICAS QUANTITATIVAS E QUALITATIVAS DE CAATINGA RALEADA SOB PASTEJO DE OVINOS, SERRA TALHADA (PE

    Directory of Open Access Journals (Sweden)

    OSNIEL FARIA DE OLIVEIRA

    2015-01-01

    Full Text Available The aim was to study during a year, the quantitative and qualitative characteristics of the thinning Caatinga grazing sheep at continuous stocking, in Serra Talhada-PE. The research consisted of data collection of vegetation and sheep, in 38 hectares of Caatinga from a private farm. We evaluated the herbage mass, herbal chemical composition, botanical composition, bare soil, litter, plants height, stocking rate, animal performance and herbage allowance. Herbage mass ranged from 422 ± 42 to 1262 ± 95 kg DM.ha-1within the period January 2011 to January 2012, which led to decreased herbage allowance (13,1± 1,3 a 56,4± 4,2 kg MS.kg PV- 1 . The weight gain of sheep observed was 2.0 ± 2.2 kg. head-1 .period-1 and 3.8 ± 4.0 kg.ha-1 .period-1 . The litter during the dry season was higher in October 2011 (38.8 ± 4.1% and January 2012 (41.4 ± 4.3%. Increased values were observed on bare soil, mainly in dry season, averaging 24.4 ± 1.5%. With the advance of the dry season, the concentrations of DM, NDF, ADF and TC of pasture increased, while the CP, MM, and NFC decreased. In general, the Caatinga show varieties in the range of herbage mass, forage chemical composition, and animal performance, over the year.

  12. Mass Customization of process plants

    DEFF Research Database (Denmark)

    Hvam, Lars

    2006-01-01

    This case study describes how F.L.Smidth A/S, a manufacturer of large processing plants for cement production, has applied the principles of mass customisation in the area of highly complex, custom engineered products. The company has based its sales process on a configuration system to achieve...

  13. Quark masses and their hierarchies

    Science.gov (United States)

    Ida, M.

    1987-12-01

    Electroweak symmetry breaking is attributed to dynamical generation of quark masses. Quarks q (and leptons l) are assumed to be produced by hypercolor confinement of preons at an intermediate scale Λ hc. Hierarchies observed in the q mass spectra can be explained by a BCS mechanism if the color interaction is enough asymptotically free and if residual ones emerging by the confinement are medium strong. The former assumption claims that N≦4, where N is the family number of q and l. Dynamical equations to determine q masses and mixings are given, but they require knowledge on the physics at Λ hc. A phenomenological approach is also made on the basis of an SU(7)× SU(7) chiral preon model with N=4. The mass ratio m t/ mb is related to ( m c/ m s)ηB with η B≃1.1 and m t'/ mb' to ( m u/ m d)ηA with η A≃1.4. In this scheme the fourth down quark is the heaviest (˜ 110 GeV) and contributes dominantly to F 2, where F is the Fermi scale.

  14. Mass production of entomopathogenic hypocreales

    Science.gov (United States)

    The Hypocreales, Beauveria bassiana, Metarhizium anisopliae sensu lato, Isaria fumosorosea and I. farinosus, and Nomuraea rileyi, have become important insect control agents in recent times and consequently subjects of much scientific study and development. Mass production of infective stages is imp...

  15. Mass Varying Neutrinos in Supernovae

    CERN Document Server

    Rossi-Torres, F; de Holanda, P C; Peres, O L G

    2010-01-01

    We study limits for the mass varying neutrino model, using constrains from supernova neutrinos placed by the r-process condition, $Y_e<0.5$. Also, we use this model in a supernova environment to study the regions of survival probability in the oscillation space parameter ($\\tan^2\\theta$ and $\\Delta m^2_0$), considering the channel $\

  16. Triage in mass casualty situations

    African Journals Online (AJOL)

    More often than not major incidents and disasters result in a mass casualty situation, which places ... As part of the FIFA 2010 preparation, the National Department of Health ... Over-triage of children in this way is acceptable because children ...

  17. Scale Of Fermion Mass Generation

    CERN Document Server

    Niczyporuk, J M

    2002-01-01

    Unitarity of longitudinal weak vector boson scattering implies an upper bound on the scale of electroweak symmetry breaking, Λ EWSB ≡ 8pv ≈ 1 TeV. Appelquist and Chanowitz have derived an analogous upper bound on the scale of fermion mass generation, proportional to v 2/mf, by considering the scattering of same-helicity fermions into pairs of longitudinal weak vector bosons in a theory without a standard Higgs boson. We show that there is no upper bound, beyond that on the scale of electroweak symmetry breaking, in such a theory. This result is obtained by considering the same process, but with a large number of longitudinal weak vector bosons in the final state. We further argue that there is no scale of (Dirac) fermion mass generation in the standard model. In contrast, there is an upper bound on the scale of Majorana-neutrino mass generation, given by ΛMaj ≡ 4πv2/m ν. In general, the upper bound on the scale of fermion mass generation depend...

  18. Top quark mass and kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Barberis, Emanuela; /Northeastern U.

    2006-05-01

    A summary of the results on the measurement of the Top Quark mass and the study of the kinematics of the t{bar t} system at the Tevatron collider is presented here. Results from both the CDF and D0 collaborations are reported.

  19. Coping With the Mass Media.

    Science.gov (United States)

    Littell, Joseph Fletcher, Ed.

    This textbook, one of "The Language of Man" series, has five sections, each including several articles. Introductory articles detail the role of the mass media in our lives; other sections deal with television, movies, newspapers, and the ideas of Marshall McLuhan. The focus of concern is less with aesthetics and more with the social…

  20. Bias in the Mass Media.

    Science.gov (United States)

    Cirino, Robert

    Non-language elements of bias in mass media--such as images, sounds, tones of voices, inflection, and facial expressions--are invariably integrated with the choice of language. Further, they have an emotional impact that is often greater than that of language. It is essential that the teacher of English deal with this non-language bias since it is…

  1. (Hybrid) Baryons Symmetries and Masses

    CERN Document Server

    Page, P R

    1999-01-01

    We construct (hybrid) baryons in the flux-tube model of Isgur and Paton. In the limit of adiabatic quark motion, we build proper eigenstates of orbital angular momentum and construct the flavour, spin and J^P of hybrid baryons from the symmetries of the system. The lowest mass hybrid baryon is estimated at approximately 2 GeV.

  2. Mass Conservation and Chemical Kinetics.

    Science.gov (United States)

    Barbara, Thomas M.; Corio, P. L.

    1980-01-01

    Presents a method for obtaining all mass conservation conditions implied by a given mechanism in which the conditions are used to simplify integration of the rate equations and to derive stoichiometric relations. Discusses possibilities of faulty inference of kinetic information from a given stoichiometry. (CS)

  3. Mass Customization and Performance Assessment

    DEFF Research Database (Denmark)

    Storbjerg, Simon Haahr; Brunø, Thomas Ditlev; Nielsen, Kjeld

    2014-01-01

    Mass customization (MC) has been introduced as the future of manufacturing, and great results have been proven. Recent research, however, documents a high failure rate for companies trying to adapt to MC as a business strategy. Making this transition is, as highlighted by several scholars...

  4. Lemaitre model and cosmic mass

    CERN Document Server

    Faraoni, Valerio

    2015-01-01

    The mass of a sphere of simmetry in the Lemaitre universe is discussed using the Hawking-Hayward quasi-local energy and clarifying existing ambiguities. A covariantly conserved current introduced by Cahill and McVittie is shown to be a multiple of the Kodama energy current.

  5. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    Urban, Pawel L.

    2016-10-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry-especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue 'Quantitative mass spectrometry'.

  6. Consumer Preferences for Mass Customization

    NARCIS (Netherlands)

    B.G.C. Dellaert (Benedict); S. Stremersch (Stefan)

    2004-01-01

    textabstractIncreasingly, firms adopt mass customization, which allows consumers to customize products by self-selecting their most preferred composition of the product for a predefined set of modules. For example, PC vendors such as Dell allow customers to customize their PC by choosing the type of

  7. Quantitative mass spectrometry: an overview

    Science.gov (United States)

    2016-01-01

    Mass spectrometry (MS) is a mainstream chemical analysis technique in the twenty-first century. It has contributed to numerous discoveries in chemistry, physics and biochemistry. Hundreds of research laboratories scattered all over the world use MS every day to investigate fundamental phenomena on the molecular level. MS is also widely used by industry—especially in drug discovery, quality control and food safety protocols. In some cases, mass spectrometers are indispensable and irreplaceable by any other metrological tools. The uniqueness of MS is due to the fact that it enables direct identification of molecules based on the mass-to-charge ratios as well as fragmentation patterns. Thus, for several decades now, MS has been used in qualitative chemical analysis. To address the pressing need for quantitative molecular measurements, a number of laboratories focused on technological and methodological improvements that could render MS a fully quantitative metrological platform. In this theme issue, the experts working for some of those laboratories share their knowledge and enthusiasm about quantitative MS. I hope this theme issue will benefit readers, and foster fundamental and applied research based on quantitative MS measurements. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644965

  8. The masses of neutron stars

    CERN Document Server

    Horvath, J E

    2016-01-01

    We present in this article an overview of the problem of neutron star masses. After a brief appraisal of the methods employed to determine the masses of neutron stars in binary systems, the existing sample of measured masses is presented, with a highlight on some very well-determined cases. We discuss the analysis made to uncover the underlying distribution and a few robust results that stand out from them. The issues related to some particular groups of neutron stars originated from different channels of stellar evolution are shown. Our conclusions are that last century's paradigm that there a single, $1.4 M_{\\odot}$ scale is too simple. A bimodal or even more complex distribution is actually present. It is confirmed that some neutron stars have masses of $\\sim 2 M_{\\odot}$, and, while there is still no firm conclusion on the maximum and minimum values produced in nature, the field has entered a mature stage in which all these and related questions can soon be given an answer.

  9. Representative mass reduction in sampling

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Harry Kim; Dahl, Casper Kierulf

    2004-01-01

    We here present a comprehensive survey of current mass reduction principles and hardware available in the current market. We conduct a rigorous comparison study of the performance of 17 field and/or laboratory instruments or methods which are quantitatively characterized (and ranked) for accuracy...

  10. Consumer Preferences for Mass Customization

    NARCIS (Netherlands)

    B.G.C. Dellaert (Benedict); S. Stremersch (Stefan)

    2004-01-01

    textabstractIncreasingly, firms adopt mass customization, which allows consumers to customize products by self-selecting their most preferred composition of the product for a predefined set of modules. For example, PC vendors such as Dell allow customers to customize their PC by choosing the type of

  11. Gravitational contribution to fermion masses

    CERN Document Server

    Tiemblo, A; Tiemblo, Alfredo; Tresguerres, Romualdo

    2005-01-01

    In the context of a nonlinear gauge theory of the Poincar\\'e group, we show that covariant derivatives of Dirac fields include a coupling to the translational connections, manifesting itself in the matter action as a universal background mass contribution to fermions.

  12. Low Bone Mass in Thalassemia

    Science.gov (United States)

    4 Low Bone Mass in Thalassemia • In addition to a diet rich in calcium and vitamin D, your doctor may recommend taking calcium and/or vitamin D ... Zoledronic acid may be beneficial to patients with thalassemia and osteoporosis; other trials are investigating whether increasing ...

  13. Mass Substructure in Abell 3128

    Science.gov (United States)

    McCleary, J.; dell'Antonio, I.; Huwe, P.

    2015-05-01

    We perform a detailed two-dimensional weak gravitational lensing analysis of the nearby (z = 0.058) galaxy cluster Abell 3128 using deep ugrz imaging from the Dark Energy Camera (DECam). We have designed a pipeline to remove instrumental artifacts from DECam images and stack multiple dithered observations without inducing a spurious ellipticity signal. We develop a new technique to characterize the spatial variation of the point-spread function that enables us to circularize the field to better than 0.5% and thereby extract the intrinsic galaxy ellipticities. By fitting photometric redshifts to sources in the observation, we are able to select a sample of background galaxies for weak-lensing analysis free from low-redshift contaminants. Photometric redshifts are also used to select a high-redshift galaxy subsample with which we successfully isolate the signal from an interloping z = 0.44 cluster. We estimate the total mass of Abell 3128 by fitting the tangential ellipticity of background galaxies with the weak-lensing shear profile of a Navarro-Frenk-White (NFW) halo and also perform NFW fits to substructures detected in the 2D mass maps of the cluster. This study yields one of the highest resolution mass maps of a low-z cluster to date and is the first step in a larger effort to characterize the redshift evolution of mass substructures in clusters.

  14. MASS SUBSTRUCTURE IN ABELL 3128

    Energy Technology Data Exchange (ETDEWEB)

    McCleary, J.; Dell’Antonio, I.; Huwe, P., E-mail: Jacqueline_McCleary@brown.edu [Department of Physics, Brown University, Box 1843, Providence, RI 02912 (United States)

    2015-05-20

    We perform a detailed two-dimensional weak gravitational lensing analysis of the nearby (z = 0.058) galaxy cluster Abell 3128 using deep ugrz imaging from the Dark Energy Camera (DECam). We have designed a pipeline to remove instrumental artifacts from DECam images and stack multiple dithered observations without inducing a spurious ellipticity signal. We develop a new technique to characterize the spatial variation of the point-spread function that enables us to circularize the field to better than 0.5% and thereby extract the intrinsic galaxy ellipticities. By fitting photometric redshifts to sources in the observation, we are able to select a sample of background galaxies for weak-lensing analysis free from low-redshift contaminants. Photometric redshifts are also used to select a high-redshift galaxy subsample with which we successfully isolate the signal from an interloping z = 0.44 cluster. We estimate the total mass of Abell 3128 by fitting the tangential ellipticity of background galaxies with the weak-lensing shear profile of a Navarro–Frenk–White (NFW) halo and also perform NFW fits to substructures detected in the 2D mass maps of the cluster. This study yields one of the highest resolution mass maps of a low-z cluster to date and is the first step in a larger effort to characterize the redshift evolution of mass substructures in clusters.

  15. Portable Tandem Mass Spectrometer Analyzer

    Science.gov (United States)

    1991-07-01

    FILE : MHCI TUNE TABLE 84 (SCANNING with PARENT) SCAN RANGE 10.9 TO 700.0 TUNE MASS 355.0 (AUTO) >LENS 1-3 -13. 88 0. 2: POFF - 1. 2 9: COFF - 4. 1 3...electronics, and glass shops . 04- 0 4- CD IL - -- it * I ; CHAPTER 3 EXPERIMENTAL RESULTS AND SOURCE DEVELOPMENT Results with API Source Configuration

  16. Quark masses without Yukawa hierarchies

    Energy Technology Data Exchange (ETDEWEB)

    Fanchiotti, H.; Garcia-Canal, C. [Plata Univ. Nacional, Laboratorio de Fisica Teorica, Dept. de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina); Ponce, W.A. [Antioquia Univ., Instituto de Fisica, Colombia La (Argentina)

    2005-12-15

    A model based on the local gauge group SU(3){sub c}*SU(3){sub L}*U(1){sub X} without particles with exotic electric charges is shown to be able to provide the quark mass spectrum and their mixing, by means of universal see-saw mechanisms, avoiding a hierarchy in the Yukawa coupling constants. (authors)

  17. Gravitational contribution to fermion masses

    OpenAIRE

    Tiemblo, Alfredo; Tresguerres, Romualdo

    2005-01-01

    In the context of a nonlinear gauge theory of the Poincar\\'e group, we show that covariant derivatives of Dirac fields include a coupling to the translational connections, manifesting itself in the matter action as a universal background mass contribution to fermions.

  18. Gravitational contribution to fermion masses

    Energy Technology Data Exchange (ETDEWEB)

    Tiemblo, A.; Tresguerres, R. [Consejo Superior de Investigaciones Cientificas, Instituto de Matematicas y Fisica Fundamental, Madrid (Spain)

    2005-08-01

    In the context of a non-linear gauge theory of the Poincare group, we show that covariant derivatives of Dirac fields include a coupling to the translational connections, manifesting itself in the matter action as a universal background mass contribution to fermions. (orig.)

  19. Is the stop mass below the top mass?

    CERN Document Server

    de Boer, Wim; Kazakov, D I

    1994-01-01

    It is shown that a top mass of 174+/-17 GeV, as quoted recently by the CDF Collaboration, constrains the mixing angle between the Higgs doublets in the Minimal Supersymmmetric extension of the Standard Model (MSSM) to: 1.2mass. In this case the stop production in pp_bar collisions would contribute to the top signature, thus providing a possible explanation for the large effective tt_bar cross section observed by CDF.

  20. Quark ACM with topologically generated gluon mass

    CERN Document Server

    Choudhury, Ishita Dutta

    2016-01-01

    We investigate the effect of a small, gauge-invariant mass of the gluon on the anomalous chromomagnetic moment of quarks (ACM) by perturbative calculations at one loop level. The mass of the gluon is taken to have been generated via a topological mass generation mechanism, in which the gluon acquires a mass through its interaction with an antisymmetric tensor field $B_{\\mu \

  1. Aerosol MALDI mass spectrometry for bioaerosol analysis

    NARCIS (Netherlands)

    Kleefsman, W.A.

    2008-01-01

    In the thesis Aerosol MALDI mass spectrometry for bioaerosol analysis is described how the aerosol mass spectrometer of the TU Delft has been further developed for the on-line analysis of bioaerosols. Due to the implemented improvements mass spectra with high resolution and a high mass range can be

  2. Absorption Mode FTICR Mass Spectrometry Imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kilgour, D.P.A.; Konijnenburg, M.; O'Connor, P.B.; Heeren, R.M.A.

    2013-01-01

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields

  3. Galaxy And Mass Assembly (GAMA): The mass-metallicity relationship

    CERN Document Server

    Foster, C; Gunawardhana, M; Lara-Lopez, M A; Sharp, R G; Steele, O; Taylor, E N; Driver, S P; Baldryi, I K; Bamford, S P; Liske, J; Loveday, J; Norberg, P; Peacock, J A; Alpaslan, M; Bauer, A E; Bland-Hawthorn, J; Brough, S; Cameron, E; Colless, M; Conselice, C J; Croom, S M; Frenk, C S; Hill, D T; Jones, D H; Kelvin, L S; Kuijken, K; Nichol, R C; Owers, M S; Parkinson, H R; Pimbblet, K A; Popescu, C C; Prescott, M; Robotham, A S G; Lopez-Sanchez, A R; Sutherland, W J; Thomas, D; Tuffs, R J; van Kampen, E; Wijesinghe, D

    2012-01-01

    Context: The mass-metallicity relationship (MMR) of star-forming galaxies is well-established, however there is still some disagreement with respect to its exact shape and its possible dependence on other observables. Aims: We measure the MMR in the Galaxy And Mass Assembly (GAMA) survey. We compare our measured MMR to that measured in the Sloan Digital Sky Survey (SDSS) and study the dependence of the MMR on various selection criteria to identify potential causes for disparities seen in the literature. Methods: We use strong emission line ratio diagnostics to derive oxygen abundances. We then apply a range of selection criteria for the minimum signal-to-noise in various emission lines, as well as the apparent and absolute magnitude to study variations in the inferred MMR. Results: The shape and position of the MMR can differ significantly depending on the metallicity calibration and selection used. After selecting a robust metallicity calibration amongst those tested, we find that the mass-metallicity relati...

  4. Dynamical Self-mass for Massive Quarks

    CERN Document Server

    Huang, Z; Huang, Zheng

    1992-01-01

    We examine dynamical mass generation in QCD with large current mass quarks. A renormalization group analysis is performed to separate fermion self-mass into a dynamical and a kinematical part. It is shown that the energy scale og the Schwinger-Dyson (SD) equation and the effective gauge coupling are fixed by the current mass. The dynamical self-mass satisfies a homogeneous SD equation which has a trivial solution when the current mass exceeds a critical value. We therefore suggest that the quark condensate, as the function of the current mass, observes a local minimum around 2.7\\Lambda_(QCD).

  5. Communication Problems in a Mass Society: Mass Audience, Mass Communication and Development.

    Science.gov (United States)

    Moemeka, Andrew A.

    This paper examines the problem of how to reconcile the practical realities of the nature of the mass audience with the demands of personal and social development, particularly in Africa and other Third World Countries, where the demands of modernization have confronted traditional norms and values. After defining and clarifying key concepts such…

  6. Neuroscience and Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Palmblad, M N; Buchholz, B A; Hillegonds, D J; Vogel, J S

    2004-08-02

    Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.

  7. High Amplitude Secondary Mass Drive

    Energy Technology Data Exchange (ETDEWEB)

    DYCK,CHRISTOPHER WILLIAM; ALLEN,JAMES J.; HUBER,ROBERT JOHN; SNIEGOWSKI,JEFFRY J.

    2000-07-06

    In this paper we describe a high amplitude electrostatic drive for surface micromachined mechanical oscillators that may be suitable for vibratory gyroscopes. It is an advanced design of a previously reported dual mass oscillator (Dyck, et. al., 1999). The structure is a 2 degree-of-freedom, parallel-plate driven motion amplifier, termed the secondary mass drive oscillator (SMD oscillator). During each cycle the device contacts the drive plates, generating large electrostatic forces. Peak-to-peak amplitudes of 54 {micro}m have been obtained by operating the structure in air with an applied voltage of 11 V. We describe the structure, present the analysis and design equations, and show recent results that have been obtained, including frequency response data, power dissipation, and out-of- plane motion.

  8. Earth\\'s Mass Variability

    CERN Document Server

    Mawad, Ramy

    2014-01-01

    The perturbation of the Earth caused by variability of mass of Earth as additional reason with gravity of celestial bodies and shape of the Earth. The Earth eating and collecting matters from space and loss or eject matters to space through its flying in the space around the Sun. The source of the rising in the global sea level is not closed in global warming and icebergs, but the outer space is the additional important source for this rising. The Earth eats waters from space in unknown mechanism. The mass of the Earth become greater in November i.e. before transit apoapsis two months, and become latter in February i.e. after transit apoapsis to two months.

  9. The International Mass Loading Service

    CERN Document Server

    Petrov, Leonid

    2015-01-01

    The International Mass Loading Service computes four loadings: a) atmospheric pressure loading; b) land water storage loading; c) oceanic tidal loading; and d) non-tidal oceanic loading. The service provides to users the mass loading time series in three forms: 1) pre-computed time series for a list of 849 space geodesy stations; 2) pre-computed time series on the global 1deg x 1deg grid; and 3) on-demand Internet service for a list of stations and a time range specified by the user. The loading displacements are provided for the time period from 1979.01.01 through present, updated on an hourly basis, and have latencies 8-20 hours.

  10. Macroscopic-microscopic mass models

    CERN Document Server

    Nix, J R; Nix, J Rayford; Moller, Peter

    1995-01-01

    We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended-Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mass models are teaching us about such physically relevant issues as the nuclear curvature energy, a new congruence energy arising from a greater-than-average overlap of neutron and proton wave functions, the nuclear incompressibility coefficient, and the Coulomb redistribution energy arising from a central density depression. We conclude with a brief discussion of the recently discovered rock of metastable superheavy nuclei near 272:110 that had been correctly predicted by macroscopic-microscopic models, along with a possible new tack for reaching an island near 290:110 beyond our present horizon.

  11. Inflationary Predictions and Moduli Masses

    CERN Document Server

    Das, Kumar; Maharana, Anshuman

    2015-01-01

    A generic feature of inflationary models in supergravity/string constructions is vacuum misalignment for the moduli fields. The associated production of moduli particles leads to an epoch in the post-inflationary history in which the energy density is dominated by cold moduli particles. This modification of the post-inflationary history implies that the preferred range for the number of e-foldings between horizon exit of the modes relevant for CMB observations and the end of inflation $(N_k)$ depends on moduli masses. This in turn implies that the precision CMB observables $n_s$ and $r$ are sensitive to moduli masses. We analyse this sensitivity for some representative models of inflation and find the effect to be highly relevant for confronting inflationary models with observations.

  12. Relativity, potential energy, and mass

    Science.gov (United States)

    Hecht, Eugene

    2016-11-01

    This paper is an exploration of the concept of energy, illuminated by the transformative insights of the special theory of relativity. Focusing on potential energy (PE), it will be shown that PE as presently defined is in conflict with the tenets of special relativity. Even though PE remains an indispensable theoretical device its actual physicality is questionable. Moreover its ontological status is quite different from that of both kinetic energy and mass, a significant point that is not widely appreciated. We will establish that PE is a theoretical concept as opposed to an empirical one; it is a descriptor of mass-energy without a detectable physical presence of its own. PE is a measure of energy stored, it is not the energy stored.

  13. Mass extinctions and supernova explosions

    CERN Document Server

    Korschinek, Gunther

    2016-01-01

    A nearby supernova (SN) explosion could have negatively influenced life on Earth, maybe even been responsible for mass extinctions. Mass extinction poses a significant extinction of numerous species on Earth, as recorded in the paleontologic, paleoclimatic, and geological record of our planet. Depending on the distance between the Sun and the SN, different types of threats have to be considered, such as ozone depletion on Earth, causing increased exposure to the Sun's ultraviolet radiation, or the direct exposure of lethal x-rays. Another indirect effect is cloud formation, induced by cosmic rays in the atmosphere which result in a drop in the Earth's temperature, causing major glaciations of the Earth. The discovery of highly intensive gamma ray bursts (GRBs), which could be connected to SNe, initiated further discussions on possible life-threatening events in Earth's history. The probability that GRBs hit the Earth is very low. Nevertheless, a past interaction of Earth with GRBs and/or SNe cannot be exclude...

  14. Approximate twistors and positive mass

    Science.gov (United States)

    Bäckdahl, Thomas; Valiente Kroon, Juan A.

    2011-04-01

    In this paper, the problem of comparing initial data to a reference solution for the vacuum Einstein field equations is considered. This is not done in a coordinate sense, but through quantification of the deviation from a specific symmetry. In a recent paper (Bäckdahl and Valiente Kroon 2010 Phys. Rev. Lett. 104 231102), this problem was studied with the Kerr solution as a reference solution. This analysis was based on valence 2 Killing spinors. In order to better understand this construction, we analyse the analogous construction for valence 1 spinors solving the twistor equation. This yields an invariant that measures how much the initial data deviates from Minkowski data. Furthermore, we prove that this invariant vanishes if and only if the mass vanishes. Hence, we get a proof of the positivity of mass.

  15. Approximate twistors and positive mass

    Energy Technology Data Exchange (ETDEWEB)

    Baeckdahl, Thomas; Valiente Kroon, Juan A, E-mail: t.backdahl@qmul.ac.uk, E-mail: j.a.valiente-kroon@qmul.ac.uk [School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom)

    2011-04-07

    In this paper, the problem of comparing initial data to a reference solution for the vacuum Einstein field equations is considered. This is not done in a coordinate sense, but through quantification of the deviation from a specific symmetry. In a recent paper (Baeckdahl and Valiente Kroon 2010 Phys. Rev. Lett. 104 231102), this problem was studied with the Kerr solution as a reference solution. This analysis was based on valence 2 Killing spinors. In order to better understand this construction, we analyse the analogous construction for valence 1 spinors solving the twistor equation. This yields an invariant that measures how much the initial data deviates from Minkowski data. Furthermore, we prove that this invariant vanishes if and only if the mass vanishes. Hence, we get a proof of the positivity of mass.

  16. Body Mass Index and Stroke

    DEFF Research Database (Denmark)

    Andersen, Klaus Kaae; Olsen, Tom Skyhøj

    2013-01-01

    Although obesity is associated with excess mortality and morbidity, mortality is lower in obese than in normal weight stroke patients (the obesity paradox). Studies now indicate that obesity is not associated with increased risk of recurrent stroke in the years after first stroke. We studied...... the association between body mass index (BMI) and stroke patient's risk of having a history of previous stroke (recurrent stroke)....

  17. Teaching English through Mass Media

    Science.gov (United States)

    Tafani, Vilma

    2009-01-01

    This article aims at analyzing the importance of using Mass Media in the classroom and finding the ways how to use Printed and Audio-visual Media. It is the result of an in-depth study, surveys and questionnaires thus trying to make the ideas in this article more trustworthy. It is based not only on the literature review but also on long personal…

  18. Mass Customizing IT Service Agreements

    OpenAIRE

    Brocke, Henrik Finn; Uebernickel, Falk; Brenner, Walter

    2010-01-01

    IT service providers shall achieve both cost reduction in their IT operations and customer individuality in service agreements. This article suggests adapting the well known principle of mass customization to balance individuality and standardization in service agreements. Dependent on the commitment modularity type, its employment may not only save time and resources at the point of customer involvement but also allow the pre-engineering of repeatable processes of provisioning and IT operati...

  19. Dynamical Masses of Elliptical Galaxies

    CERN Document Server

    Gerhard, O E

    2002-01-01

    Recent progress in the dynamical analysis of elliptical galaxy kinematics is reviewed. Results reported briefly include (i) the surprisingly uniform anisotropy structure of luminous ellipticals, (ii) their nearly flat (to $\\sim 2R_e$) circular velocity curves, (iii) the Tully-Fisher and $M/L - L$ relations and the connection to the Fundamental Plane, and (iv) the large halo mass densities implied by the dynamical models.

  20. Neutrino Masses and Flavor Mixing

    Science.gov (United States)

    Xing, Zhi-zhong

    2010-06-01

    I give a theoretical overview of some basic properties of massive neutrinos in these lectures. Particular attention is paid to the origin of neutrino masses, the pattern of lepton flavor mixing, the feature of leptonic CP violation and the electromagnetic properties of massive neutrinos. I highlight the TeV seesaw mechanisms as a possible bridge between neutrino physics and collider physics in the era characterized by the Large Hadron Collider.

  1. Optics of mass separator I

    Energy Technology Data Exchange (ETDEWEB)

    Balestrini, S.J.

    1981-07-01

    The ion optics of an existing mass separator are documented. The elctrostatic and magnetic stages are analyzed theoretically, both separately and in combination, by paying particular attention to the ion trajectories, the linear and angular magnifications, and the dispersion. The possibility of converting the magnet into a tunable unit by means of current-carrying elements in the gap is demonstrated. The feasibility of correction coils constructed from printed circuit board is shown.

  2. Mass Graves, Landscapes of Terror

    OpenAIRE

    Ferrándiz, Francisco

    2009-01-01

    The recent exhumation of mass graves from the Spanish Civil War and the Post-War years, mostly involving the largely abandoned graves of the Francoist rearguard, have become a central element in contemporary debates about the conflict and the regime following it. In this paper, the complexity and dynamism of this process is analysed, including from political and legal initiatives of great social and media impact to local actions on the ground, at times failed, ephemeral or almost imperceptibl...

  3. Parasites in algae mass culture

    Directory of Open Access Journals (Sweden)

    Todd William Lane

    2014-06-01

    Full Text Available Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry.

  4. Mass Transfer Method and Apparatus

    DEFF Research Database (Denmark)

    1995-01-01

    The invention relates to a method for transferring mass between a flow of a first fluid, preferably a gas phase such as a combustion flue gas, and a flow of a second fluid, preferably a liquid phase, where the first fluid is contacted with the outer surface of porous (semi-permeable) membranes, e.......g. polytetrafluoroethylene (PTFE, Teflon $m(3)) membranes, in the form of hollow fibres having gas-containing pores and contacting the second fluid with the inner surface of the membranes. Useful membranes are characterized in that they e.g. have a porosity ($g(e)) of at least 0.50, a mass transfer coefficient of e.......g. at least 3 cm/s, and a tortuosity factor of e.g. at the most 1.4/$g(e) when the porosity $g(e) is lower than 0.80 and at the most 1.3/$g(e) when the porosity $g(e) is 0.80 or higher. The membranes may also be arranged in hollow tubular members where the mass transfer coefficient of the membranes...

  5. The art of thermal mass

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.

    1999-10-01

    From cave dwellers to pueblo builders, early people of the southwest used the earth to moderated the extremes of their climate. Now, at the turn of the 21st century, a Colorado builder combines ancient knowledge with high technology to create modern homes that stay naturally warm in the winter and cool in the summer. With passive solar design, incorporating lots concrete mass, Judy Niemeyer builds custom homes that hardly even need thermostats. Before clients Ralph and Sharon Dickman stumbled into Niemeyer, owner of Tierra Concrete Homes in Pueblo, Colorado, thermal mass was not in their vocabulary. Now, when temperatures reach 100 F (38 C) in July and their neighbors are running up their electric bills, the Dickmans are saving for vacation. With the thermal mass integrated into their new home, they don't need a cooling system. And in winter, their gas-fired log fireplace is about all they need to supplement the sun. ``We love the natural lighting, the open feeling and the great view out the huge windows,'' says Sharon. And they stay comfortable year-round with very low energy bills.

  6. Top Mass Measurement at CMS

    CERN Document Server

    Duda, Markus

    2006-01-01

    Given the big cross section for \\ttbar production in proton-proton collisions at 14\\TeV, the LHC with its high luminosity will be, among others,a top factory, allowing a precision measurement of the top quark mass. Based on a detailed simulation of the CMS detector, the following top mass reconstruction accuracies are possible in the respective final states with the present knowledge of experimental and theoretical uncertainties. Delta m_t (di-leptonic, 1fbinv) = pm 1.5 (stat) pm 2.9 (syst.) GeVcc Delta m_t (semi-leptonic, 1fbinv) = pm 0.7 (stat) pm 1.9 (syst.) GeVcc Delta m_t (fully hadronic, 1fbinv) = pm 0.6(stat) pm 4.2 (syst.) GeVcc Delta m_t (di-leptonic}, 10 fbinv) = pm 0.5 (stat) pm 1.1 (syst.) GeVcc Delta m_t (semi-leptonic, 10 fbinv) = pm 0.2 (stat) pm 1.1 (syst.) GeVcc Delta m_t (JPsi, 20 fbinv) = pm 1.2 (stat) pm 1.5 (syst.) GeVcc A combined top mass accuracy of mathcal O (1GeVcc) for 10-20fbinv of well-understood CMS data will be feasible.

  7. Mental health in mass gatherings

    Directory of Open Access Journals (Sweden)

    Shahbaz Ali Khan

    2016-01-01

    Full Text Available Background: Hajj pilgrimage, in Saudi Arabia, is one of the world's largest religious mass gatherings. We have similar mass gathering scenarios in India such as the Amarnath Yatra and Kumbh. A unique combination of physical, physiological, and psychological factors makes this pilgrimage a very stressful milieu. We studied the emergence of psychopathology and its determinants, in this adverse environment in mass gathering situation, in Indian pilgrims on Hajj 2016. Materials and Methods: This is a descriptive study analyzing the mental morbidity in 1.36 lakh Indian pilgrims during Hajj 2016, using SPSS software version 19. Results: Totally 182 patients reported psychological problems. Twenty-two patients (12% required admission. Twelve (6.8% pilgrims reported a past history of a mental illness. One hundred and sixty-five (93.2% patients never had any mental symptoms earlier in life. The most common illnesses seen were stress related (45.7% followed by psychosis (9.8%, insomnia (7.3%, and mood disorders (5.6%. The most common symptoms recorded were apprehension (45%, sleep (55%, anxiety (41%, and fear of being lost (27%. Psychotropics were prescribed for 46% of pilgrims. All patients completed their Hajj successfully and returned to India. Conclusions: Cumulative stress causes full spectrum of mental decompensation, and prompt healing is aided by simple nonpharmacological measures including social support and counseling in compatible sociolinguistic milieu.

  8. Mass Transfer Method and Apparatus

    DEFF Research Database (Denmark)

    1995-01-01

    .g. at least 3 cm/s, and a tortuosity factor of e.g. at the most 1.4/$g(e) when the porosity $g(e) is lower than 0.80 and at the most 1.3/$g(e) when the porosity $g(e) is 0.80 or higher. The membranes may also be arranged in hollow tubular members where the mass transfer coefficient of the membranes......The invention relates to a method for transferring mass between a flow of a first fluid, preferably a gas phase such as a combustion flue gas, and a flow of a second fluid, preferably a liquid phase, where the first fluid is contacted with the outer surface of porous (semi-permeable) membranes, e.......g. polytetrafluoroethylene (PTFE, Teflon $m(3)) membranes, in the form of hollow fibres having gas-containing pores and contacting the second fluid with the inner surface of the membranes. Useful membranes are characterized in that they e.g. have a porosity ($g(e)) of at least 0.50, a mass transfer coefficient of e...

  9. Mass-deformed Brane Tilings

    CERN Document Server

    Bianchi, Massimo; Hanany, Amihay; Morales, Jose Francisco; Pacifici, Daniel Ricci; Seong, Rak-Kyeong

    2014-01-01

    We study renormalization group flows among N=1 SCFTs realized on the worldvolume of D3-branes probing toric Calabi-Yau singularities, thus admitting a brane tiling description. The flows are triggered by masses for adjoint or vector-like pairs of bifundamentals and are generalizations of the Klebanov-Witten construction of the N=1 theory for the conifold starting from the N=2 theory for the C^2/Z_2 orbifold. In order to preserve the toric condition pairs of masses with opposite signs have to be switched on. We offer a geometric interpretation of the flows as complex deformations of the Calabi-Yau singularity preserving the toric condition. For orbifolds, we support this interpretation by an explicit string amplitude computation of the gauge invariant mass terms generated by imaginary self-dual 3-form fluxes in the twisted sector. In agreement with the holographic a-theorem, the volume of the Sasaki-Einstein 5-base of the Calabi-Yau cone always increases along the flow.

  10. Neutrino mass sum rules and symmetries of the mass matrix

    Energy Technology Data Exchange (ETDEWEB)

    Gehrlein, Julia [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Spinrath, Martin [Karlsruhe Institute of Technology, Institut fuer Theoretische Teilchenphysik, Karlsruhe (Germany); National Center for Theoretical Sciences, Physics Division, Hsinchu (China)

    2017-05-15

    Neutrino mass sum rules have recently gained again more attention as a powerful tool to discriminate and test various flavour models in the near future. A related question which has not yet been discussed fully satisfactorily was the origin of these sum rules and if they are related to any residual or accidental symmetry. We will address this open issue here systematically and find previous statements confirmed. Namely, the sum rules are not related to any enhanced symmetry of the Lagrangian after family symmetry breaking but they are simply the result of a reduction of free parameters due to skillful model building. (orig.)

  11. Improving the mass determination of Galactic Cepheids

    CERN Document Server

    Bono, G; Marconi, M; Fouqué, P; Caputo, F

    2001-01-01

    We have selected a sample of Galactic Cepheids for which accurate estimates of radii, distances, and photometric parameters are available. The comparison between their pulsation masses, based on new Period-Mass-Radius (PMR) relations, and their evolutionary masses, based on both optical and NIR Color-Magnitude (CM) diagrams, suggests that pulsation masses are on average of the order of 10% smaller than the evolutionary masses. Current pulsation masses show, at fixed radius, a strongly reduced dispersion when compared with values published in literature.The increased precision in the pulsation masses is due to the fact that our predicted PMR relations based on nonlinear, convective Cepheid models present smaller standard deviations than PMR relations based on linear models. At the same time, the empirical radii of our Cepheid sample are typically accurate at the 5% level. Our evolutionary mass determinations are based on stellar models constructed by neglecting the effect of mass-loss during the He burning pha...

  12. How many species have mass M?

    CERN Document Server

    Clauset, Aaron; Redner, Sidney

    2008-01-01

    Within large taxonomic assemblages, the number of species with adult body mass M is characterized by a broad but asymmetric distribution, with the largest mass being orders of magnitude larger than the typical mass. This canonical shape can be explained by cladogenetic diffusion that is bounded below by a hard limit on viable species mass and above by extinction risks that increase weakly with mass. Here we introduce and analytically solve a simplified cladogenetic diffusion model. When appropriately parameterized, the diffusion-reaction equation predicts mass distributions that are in good agreement with data on 4002 terrestrial mammal from the late Quaternary and 8617 extant bird species. Under this model, we show that a specific tradeoff between the strength of within-lineage drift toward larger masses (Cope's rule) and the increased risk of extinction from increased mass is necessary to produce realistic mass distributions for both taxa. We then make several predictions about the evolution of avian specie...

  13. Top quark mass: past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Gaston; /Fermilab

    2007-07-01

    The top quark is the most massive elementary particle discovered thus far. Its large mass may help explain the mechanism by which fundamental particles gain mass - the Standard Model's greatest standing mystery. Today the top quark mass, together with the W boson mass, plays an important role in constraining the Higgs boson mass. The current status of the top quark mass measurement and a brief outline of the expectation at the Large Hadron Collider and the International Linear Collider will be covered.

  14. Photobioreactors for mass cultivation of algae.

    Science.gov (United States)

    Ugwu, C U; Aoyagi, H; Uchiyama, H

    2008-07-01

    Algae have attracted much interest for production of foods, bioactive compounds and also for their usefulness in cleaning the environment. In order to grow and tap the potentials of algae, efficient photobioreactors are required. Although a good number of photobioreactors have been proposed, only a few of them can be practically used for mass production of algae. One of the major factors that limits their practical application in algal mass cultures is mass transfer. Thus, a thorough understanding of mass transfer rates in photobioreactors is necessary for efficient operation of mass algal cultures. In this review article, various photobioreactors that are very promising for mass production of algae are discussed.

  15. Zero voltage mass spectrometry probes and systems

    Energy Technology Data Exchange (ETDEWEB)

    Cooks, Robert Graham; Wleklinski, Michael Stanley; Bag, Soumabha; Li, Yafeng

    2017-10-10

    The invention generally relates to zero volt mass spectrometry probes and systems. In certain embodiments, the invention provides a system including a mass spectrometry probe including a porous material, and a mass spectrometer (bench-top or miniature mass spectrometer). The system operates without an application of voltage to the probe. In certain embodiments, the probe is oriented such that a distal end faces an inlet of the mass spectrometer. In other embodiments, the distal end of the probe is 5 mm or less from an inlet of the mass spectrometer.

  16. The mass-luminosity relation for stars of mass 1.0 to 0.08 solar mass

    Science.gov (United States)

    Henry, Todd J.; Mccarthy, Donald W., Jr.

    1993-01-01

    Mass-luminosity relations determined at IR wavelengths are presented for stars with masses 1.0 to 0.08 solar mass. Using IR speckle imaging techniques on a sample of nearby binaries, we have been able to concentrate on the lower main sequence, for which an accurate mass-luminosity calibration has remained problematic. In addition, the mass-visual luminosity relation for stars with 2.0-0.08 solar mass is produced by implementing new photometric relations linking V to JHK wavelengths for the nearby stars, supplemented with eclipsing binary information. These relations predict that objects with masses of about 0.08 solar mass have M(K) of about 10 and M(V) of about 18.

  17. High Mass Accuracy and High Mass Resolving Power FT-ICR Secondary Ion Mass Spectrometry for Biological Tissue Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Donald F.; Kiss, Andras; Leach, Franklin E.; Robinson, Errol W.; Pasa-Tolic, Ljiljana; Heeren, Ronald M.

    2013-07-01

    Biological tissue imaging by secondary ion mass spectrometry has seen rapid development with the commercial availability of polyatomic primary ion sources. Endogenous lipids and other small bio-molecules can now be routinely mapped on the micrometer scale. Such experiments are typically performed on time-of-flight mass spectrometers for high sensitivity and high repetition rate imaging. However, such mass analyzers lack the mass resolving power to ensure separation of isobaric ions and the mass accuracy for exact mass elemental formula assignment. We have recently reported a secondary ion mass spectrometer with the combination of a C60 primary ion gun with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) for high mass resolving power, high mass measurement accuracy and tandem mass spectrometry capabilities. In this work, high specificity and high sensitivity secondary ion FT-ICR MS was applied to chemical imaging of biological tissue. An entire rat brain tissue was measured with 150 μm spatial resolution (75 μm primary ion spot size) with mass resolving power (m/Δm50%) of 67,500 (at m/z 750) and root-mean-square measurement accuracy less than two parts-per-million for intact phospholipids, small molecules and fragments. For the first time, ultra-high mass resolving power SIMS has been demonstrated, with m/Δm50% > 3,000,000. Higher spatial resolution capabilities of the platform were tested at a spatial resolution of 20 μm. The results represent order of magnitude improvements in mass resolving power and mass measurement accuracy for SIMS imaging and the promise of the platform for ultra-high mass resolving power and high spatial resolution imaging.

  18. Selling to the moneyed masses.

    Science.gov (United States)

    Nunes, Paul F; Johnson, Brian A; Breene, R Timothy S

    2004-01-01

    Over the past decade, the distribution of household incomes has shifted so much that a much larger proportion of consumers now earn significantly higher-than-average incomes--while still falling short of being truly rich. As a result, what used to be a no-man's-land for new product introductions has in many categories become an extremely profitable "new middle ground." How can marketers capitalize on this new territory? The key, say the authors, is to rethink the positioning and design of offerings and the ways they can be brought to market. Take, for instance, how Procter & Gamble redefined the positioning map for tooth-whitening solutions. A decade ago, dental centers were popularizing expensive bleaching techniques that put the price of a professionally brightened smile in the 400 dollars range. At the low end, consumers also had the choice of whitening toothpastes that cost anywhere from 2 dollars to 8 dollars. P&G wisely positioned itself between the two ends, successfully targeting the new mass market with its 35 dollars Whitestrips. In product categories where it's clear the middle ground has already been populated, it's important for companies to design or redesign offerings to compete. An example is the Polo shirt. How do you sell a man yet another one after he's bought every color he wants? Add some features, and call it a golf shirt. Here, marketers have introduced designs based on the concept of "occasional use" in order to stand out. Finally, companies wishing to reach the "almost rich" can change how they go to market. Perhaps no mass retailer has made a stronger bid for the mass affluent than Target Stores, which has pioneered a focus the company itself characterizes as upscale discount. The strategy has made Target an everyday shopping phenomenon among well-heeled urbanites and prosperous professionals.

  19. Flavor symmetries and fermion masses

    Energy Technology Data Exchange (ETDEWEB)

    Rasin, A.

    1994-04-01

    We introduce several ways in which approximate flavor symmetries act on fermions and which are consistent with observed fermion masses and mixings. Flavor changing interactions mediated by new scalars appear as a consequence of approximate flavor symmetries. We discuss the experimental limits on masses of the new scalars, and show that the masses can easily be of the order of weak scale. Some implications for neutrino physics are also discussed. Such flavor changing interactions would easily erase any primordial baryon asymmetry. We show that this situation can be saved by simply adding a new charged particle with its own asymmetry. The neutrality of the Universe, together with sphaleron processes, then ensures a survival of baryon asymmetry. Several topics on flavor structure of the supersymmetric grand unified theories are discussed. First, we show that the successful predictions for the Kobayashi-Maskawa mixing matrix elements, V{sub ub}/V{sub cb} = {radical}m{sub u}/m{sub c} and V{sub td}/V{sub ts} = {radical}m{sub d}/m{sub s}, are a consequence of a large class of models, rather than specific properties of a few models. Second, we discuss how the recent observation of the decay {beta} {yields} s{gamma} constrains the parameter space when the ratio of the vacuum expectation values of the two Higgs doublets, tan{Beta}, is large. Finally, we discuss the flavor structure of proton decay. We observe a surprising enhancement of the branching ratio for the muon mode in SO(10) models compared to the same mode in the SU(5) model.

  20. Dirac Neutrino Masses in NCG

    Institute of Scientific and Technical Information of China (English)

    LI Chang-Hui; DING Hao-Gang; DAI Jian; SONG Xing-Chang

    2001-01-01

    Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.

  1. Neutrino Masses and GUT Baryogenesis

    CERN Document Server

    López-Pérez, J A

    2003-01-01

    We reconsider the GUT-baryogenesis mechanism for generating the baryon asymmetry of the Universe. The baryon asymmetry is produced by the out of equilibrium decay of coloured Higgs bosons at the GUT scale, conserving B-L. If neutrinos are Majorana particles, lepton number violating interactions erase the lepton number excess, but part of the baryon asymmetry may be preserved, provided those interactions are not in thermal equilibrium when the sphaleron processes become effective, at $T \\sim 10^{12}~ GeV$. We analyse whether this mechanism for baryogenesis is feasible in a variety of GUT models of fermion masses proposed in the literature, based on horizontal symmetries.

  2. Deterring Mass-Casualty Terrorism

    Science.gov (United States)

    2002-01-01

    om pa ny (T ho m as B ra y) Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...actions that could create mass casualties or specific types of attack? Should the ob- jective be preventing conflict escala - tion over a determined...E G LO B A L W A R O N T E R R O R IS M Simulated attack, Foggy Shores 02–06. 30 th C om m un ic at io ns S qu ad ro n (J en ni fe r C . W

  3. Direct measurements of neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Holzschuh, E. [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    The direct measurements have so far given no indication for a nonzero (positive) mass of any of the three known neutrinos. The experiments measuring the tau and the muon neutrino are good shape. The tritium experiments are in an unfortunate situation. It is unclear to me whether the problems are experimental or theoretical or a combination of both. The electronic final states distribution have been calculated, but the results have never been tested experimentally. The most important question to be answered is about the validity of the sudden approximation. (author) 9 figs., 2 tabs., 16 refs.

  4. Decidualized Ovarian Mass Mimicking Malignancy

    Directory of Open Access Journals (Sweden)

    Lufee Wong

    2015-01-01

    Full Text Available Deciduosis classically occurs in the context of known endometriosis in the pelvis, most commonly in the ovaries, but also in the peritoneum. However, ovarian deciduosis outside the context of endometriosis is rare and makes diagnosis difficult, especially as the sonographic appearance suggests a malignant process. We report a case of decidualized ovarian mass in a patient without prior history of endometriosis that mimicked an ovarian malignancy. MRI may be a useful imaging modality to monitor these lesions and guide management. Consultation with a multidisciplinary team accustomed to such conditions will help to tailor the management to each individual.

  5. No Change of Body Mass, Fat Mass, and Skeletal Muscle Mass in Ultraendurance Swimmers after 12 Hours of Swimming

    Science.gov (United States)

    Knechtle, Beat; Knechtle, Patrizia; Kaul, Rene; Kohler, Gotz

    2009-01-01

    We evaluated whether ultraendurance swimmers suffer a change of body mass, fat mass, skeletal muscle mass, total body water, and specific gravity of urine during a 12-hr swim in 12 male Caucasian ultraswimmers. Proton nuclear magnetic resonance of urine samples before and after the race was performed to detect alanine, lactate, and…

  6. The Use of Gas Chromatography and Mass Spectrometry to Introduce General Chemistry Students to Percent Mass and Atomic Mass Calculations

    Science.gov (United States)

    Pfennig, Brian W.; Schaefer, Amy K.

    2011-01-01

    A general chemistry laboratory experiment is described that introduces students to instrumental analysis using gas chromatography-mass spectrometry (GC-MS), while simultaneously reinforcing the concepts of mass percent and the calculation of atomic mass. Working in small groups, students use the GC to separate and quantify the percent composition…

  7. The Use of Gas Chromatography and Mass Spectrometry to Introduce General Chemistry Students to Percent Mass and Atomic Mass Calculations

    Science.gov (United States)

    Pfennig, Brian W.; Schaefer, Amy K.

    2011-01-01

    A general chemistry laboratory experiment is described that introduces students to instrumental analysis using gas chromatography-mass spectrometry (GC-MS), while simultaneously reinforcing the concepts of mass percent and the calculation of atomic mass. Working in small groups, students use the GC to separate and quantify the percent composition…

  8. Characterizing simulated galaxy stellar mass histories

    CERN Document Server

    Cohn, J D

    2014-01-01

    Galaxy formation simulations can now predict many galaxy properties and their evolution through time. To go beyond studying average stellar mass history properties, we classified ensembles of simulated stellar mass histories, holding fixed their z=0 stellar mass. We applied principal component analysis (PCA) to stellar mass histories from the dark matter plus semi-analytic Millennium simulation and the hydrodynamical OverWhelmingly Large Simulations (OWLS) project, finding that a large fraction of the total scatter around the average stellar mass history for each sample is due to only one PCA fluctuation. This fluctuation differs between some different models sharing the same z=0 stellar mass and between lower (<=3e10 M_o) and higher final stellar mass Millennium samples. We correlated the PCA characterization with several $z=0$ galaxy observables (in principle observable in a survey) and galaxy halo history properties. We also explored separating galaxy stellar mass histories into classes, using the large...

  9. Quark mass effects in quark number susceptibilities

    CERN Document Server

    Graf, Thorben

    2016-01-01

    The quark degrees of freedom of the QGP with special focus on mass effects are investigated. A next-to-leading-order perturbation theory approach with quark mass dependence is applied and compared to lattice QCD results.

  10. NICHD Biomedical Mass Spectrometry Core Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The NICHD Biomedical Mass Spectrometry Core Facility was created under the auspices of the Office of the Scientific Director to provide high-end mass-spectrometric...

  11. Zero G Mass Measurement Device (ZGMMD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Zero Gravity Mass Measurement Device (ZGMMD) provides the ability to measure the mass of samples in a microgravity environment, like that found on the...

  12. Nonuniversal Gaugino Masses and Muon g-2

    CERN Document Server

    Gogoladze, Ilia; Shafi, Qaisar; Un, Cem Salih

    2014-01-01

    We consider two classes of supersymmetric models with nonuniversal gaugino masses at M_GUT in an attempt to resolve the apparent muon g-2 anomaly encountered in the Standard Model. We explore two distinct scenarios, one in which all gaugino masses have the same sign at M_GUT, and a second case with opposite sign gaugino masses. The sfermion masses in both cases are assumed to be universal at M_GUT. We exploit the non universality among gaugino masses to realize large mass splitting between the colored and non-colored sfermions. Thus, the sleptons can have masses in the few hundred GeV range, whereas the colored sparticles turn out to be an order of magnitude or so heavier. In both models the resolution of the muon g-2 anomaly is compatible, among other things, with a 125-126 GeV Higgs boson mass and the WMAP dark matter bounds.

  13. The dynamical mass of S Muscae

    Science.gov (United States)

    Bohm-Vitense, Erika; Clerk, M.; Cottrell, P. L.; Wallerstein, George

    1990-01-01

    The amplitudes and phase relations of pulsational velocities of the Cepheid S Muscae, measured for lines originating at different atmospheric depths, are investigated. A mass M(A) = 4.4 + or - 0.5 solar masses is found for the Cepheid; however, the Cepheid is the evolved star and should have a mass larger than that of its companion. If the measured velocity differences are too low by 2.5 km/s on the average, then the mass ratio M(B)/M(A) may be decreased to 0.94, giving an estimated upper limit to the Cepheid mass of 6.1 solar masses, consistent with the Cepheid being the more evolved star. Considering all the uncertainties, it is concluded that the mass of the Cepheid is between 4.6 and 6.1 solar masses.

  14. Zero G Mass Measurement Device (ZGMMD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Zero G Mass Measurement Device (ZGMMD) will provide the ability to quantify the mass of objects up to 2,000 grams, including live animal specimens in a zero G...

  15. System precisely controls oscillation of vibrating mass

    Science.gov (United States)

    Hancock, D. J.

    1967-01-01

    System precisely controls the sinusoidal amplitude of a vibrating mechanical mass. Using two sets of coils, the system regulates the drive signal amplitude at the precise level to maintain the mechanical mass when it reaches the desired vibration amplitude.

  16. Representative mass reduction in sampling

    DEFF Research Database (Denmark)

    Petersen, Lars; Esbensen, Harry Kim; Dahl, Casper Kierulf

    2004-01-01

    We here present a comprehensive survey of current mass reduction principles and hardware available in the current market. We conduct a rigorous comparison study of the performance of 17 field and/or laboratory instruments or methods which are quantitatively characterized (and ranked) for accuracy...... always be representative in the full Theory of Sampling (TOS) sense. This survey also allows empirical verification of the merits of the famous ??Gy?s formula?? for order-of-magnitude estimation of the Fundamental Sampling Error (FSE).......We here present a comprehensive survey of current mass reduction principles and hardware available in the current market. We conduct a rigorous comparison study of the performance of 17 field and/or laboratory instruments or methods which are quantitatively characterized (and ranked) for accuracy...... dividers, the Boerner Divider, the ??spoon method??, alternate/fractional shoveling and grab sampling. Only devices based on riffle splitting principles (static or rotational) passes the ultimate representativity test (with minor, but significant relative differences). Grab sampling, the overwhelmingly...

  17. A model of mass extinction

    CERN Document Server

    Newman, M E J

    1997-01-01

    A number of authors have in recent years proposed that the processes of macroevolution may give rise to self-organized critical phenomena which could have a significant effect on the dynamics of ecosystems. In particular it has been suggested that mass extinction may arise through a purely biotic mechanism as the result of so-called coevolutionary avalanches. In this paper we first explore the empirical evidence which has been put forward in favor of this conclusion. The data center principally around the existence of power-law functional forms in the distribution of the sizes of extinction events and other quantities. We then propose a new mathematical model of mass extinction which does not rely on coevolutionary effects and in which extinction is caused entirely by the action of environmental stresses on species. In combination with a simple model of species adaptation we show that this process can account for all the observed data without the need to invoke coevolution and critical processes. The model al...

  18. [Multiple injuries in mass accidents].

    Science.gov (United States)

    Wondrák, E

    1984-01-01

    The treatment starts with reanimation, managing the shock, followed by life-saving surgery on the central nervous system, chest, abdomen, large blood vessels and the uropoietic system. From the very beginning the therapy should be conducted on an intradisciplinary basis, first with the anaesthesiologist, later with other specialists as required. Once the patient's life has been saved, treatment of eyes, hands and systematic attention to extremities should follow. Shock has to be managed within 24 hours. Luxations of large joints should be reposed on the date of injury, open fractures closed, all fractures immobilized in favourable position. No extension should be applied in patients suffering from brain injuries; fractures of the femur should be fixed surgically by a second team in the course of the neurosurgical operation. A stomatologist's assistance makes general anaesthesia possible even with fractures of the jaw. In mass accidents the therapeutic plan for the polytraumatized should be fixed on the following day. A mass accident involving 35 injured treated within two and a half hours demonstrates this procedure in 7 polytraumatized persons.

  19. Mass Spectrometry Applications for Toxicology

    Science.gov (United States)

    Mbughuni, Michael M.; Jannetto, Paul J.

    2016-01-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MSn) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  20. Building brands without mass media.

    Science.gov (United States)

    Joachimsthaler, E; Aaker, D A

    1997-01-01

    Costs, market fragmentation, and new media channels that let customers bypass advertisements seem to be in league against the old ways of marketing. Relying on mass media campaigns to build strong brands may be a thing of the past. Several companies in Europe, making a virtue of necessity, have come up with alternative brand-building approaches and are blazing a trail in the post-mass-media age. In England, Nestlé's Buitoni brand grew through programs that taught the English how to cook Italian food. The Body Shop garnered loyalty with its support of environmental and social causes. Cadbury funded a theme park tied to its history in the chocolate business. Häagen-Dazs opened posh ice-cream parlors and got itself featured by name on the menus of fine restaurants. Hugo Boss and Swatch backed athletic or cultural events that became associated with their brands. The various campaigns shared characteristics that could serve as guidelines for any company hoping to build a successful brand: senior managers were closely involved with brand-building efforts; the companies recognized the importance of clarifying their core brand identity; and they made sure that all their efforts to gain visibility were tied to that core identity. Studying the methods of companies outside one's own industry and country can be instructive for managers. Pilot testing and the use of a single and continuous measure of brand equity also help managers get the most out of novel approaches in their ever more competitive world.

  1. Tractors, mass, and Weyl invariance

    Science.gov (United States)

    Gover, A. R.; Shaukat, A.; Waldron, A.

    2009-05-01

    Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus—a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner-Freedman stability bounds for Anti-de Sitter theories arise naturally as do direct derivations of the novel Weyl invariant theories given by Deser and Nepomechie. In constant curvature spaces, partially massless theories—which rely on the interplay between mass and gauge invariance—are also generated by our method. Another simple consequence is conformal invariance of the maximal depth partially massless theories. Detailed examples for spins s⩽2 are given including tractor and component actions, on-shell and off-shell approaches and gauge invariances. For all spins s⩾2 we give tractor equations of motion unifying massive, massless, and partially massless theories.

  2. Mass Spectrometry Applications for Toxicology.

    Science.gov (United States)

    Mbughuni, Michael M; Jannetto, Paul J; Langman, Loralie J

    2016-12-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MS(n)) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  3. Mass storage technology in networks

    Science.gov (United States)

    Ishii, Katsunori; Takeda, Toru; Itao, Kiyoshi; Kaneko, Reizo

    1990-08-01

    Trends and features of mass storage subsystems in network are surveyed and their key technologies spotlighted. Storage subsystems are becoming increasingly important in new network systems in which communications and data processing are systematically combined. These systems require a new class of high-performance mass-information storage in order to effectively utilize their processing power. The requirements of high transfer rates, high transactional rates and large storage capacities, coupled with high functionality, fault tolerance and flexibility in configuration, are major challenges in storage subsystems. Recent progress in optical disk technology has resulted in improved performance of on-line external memories to optical disk drives, which are competing with mid-range magnetic disks. Optical disks are more effective than magnetic disks in using low-traffic random-access file storing multimedia data that requires large capacity, such as in archive use and in information distribution use by ROM disks. Finally, it demonstrates image coded document file servers for local area network use that employ 130mm rewritable magneto-optical disk subsystems.

  4. Measuring masses of large biomolecules and bioparticles using mass spectrometric techniques.

    Science.gov (United States)

    Peng, Wen-Ping; Chou, Szu-Wei; Patil, Avinash A

    2014-07-21

    Large biomolecules and bioparticles play a vital role in biology, chemistry, biomedical science and physics. Mass is a critical parameter for the characterization of large biomolecules and bioparticles. To achieve mass analysis, choosing a suitable ion source is the first step and the instruments for detecting ions, mass analyzers and detectors should also be considered. Abundant mass spectrometric techniques have been proposed to determine the masses of large biomolecules and bioparticles and these techniques can be divided into two categories. The first category measures the mass (or size) of intact particles, including single particle quadrupole ion trap mass spectrometry, cell mass spectrometry, charge detection mass spectrometry and differential mobility mass analysis; the second category aims to measure the mass and tandem mass of biomolecular ions, including quadrupole ion trap mass spectrometry, time-of-flight mass spectrometry, quadrupole orthogonal time-of-flight mass spectrometry and orbitrap mass spectrometry. Moreover, algorithms for the mass and stoichiometry assignment of electrospray mass spectra are developed to obtain accurate structure information and subunit combinations.

  5. Mass density at geostationary orbit and apparent mass refilling

    Science.gov (United States)

    Denton, R. E.; Takahashi, Kazue; Amoh, Justice; Singer, H. J.

    2016-04-01

    We used the inferred equatorial mass density ρm,eq based on measurements of Alfvén wave frequencies measured by the GOES satellites during 1980-1991 in order to construct a number of different models of varying complexity for the equatorial mass density at geostationary orbit. The most complicated models are able to account for 66% of the variance with a typical variation from actual values of a factor of 1.56. The factors that influenced ρm,eq in the models were, in order of decreasing importance, the F10.7 EUV index, magnetic local time, the solar wind dynamic pressure Pdyn, the phase of the year, and the solar wind BZ (GSM Z direction). During some intervals, some of which were especially geomagnetically quiet, ρm,eq rose to values that were significantly higher than those predicted by our models. For 10 especially quiet intervals, we examined long-term (>1 day) apparent refilling, the increase in ρm,eq at a fixed location. We found that the behavior of ρm,eq varies for different events. In some cases, there is significant apparent refilling, whereas in other cases ρm,eq stays the same or even decreases slightly. Nevertheless, we showed that on average, ρm,eq increases exponentially during quiet intervals. There is variation of apparent refilling with respect to the phase of the solar cycle. On the third day of apparent refilling, ρm,eq has on average a similar value at solar maximum or solar minimum, but at solar maximum, ρm,eq begins with a larger value and rises relatively less than at solar minimum.

  6. Neutrino Mass Matrix with Approximate Flavor Symmetry

    CERN Document Server

    Riazuddin, M

    2003-01-01

    Phenomenological implications of neutrino oscillations implied by recent experimental data on pattern of neutrino mass matrix are disscussed. It is shown that it is possible to have a neutrino mass matrix which shows approximate flavor symmetry; the neutrino mass differences arise from flavor violation in off-diagonal Yukawa couplings. Two modest extensions of the standard model, which can embed the resulting neutrino mass matix have also been discussed.

  7. Dilaton and dynamical fermion mass generation

    Energy Technology Data Exchange (ETDEWEB)

    Hung, P.Q.; Zoupanos, G.

    1987-05-21

    In gauge theories with a hierarchy of mass scales there might appear a pseudo-Goldstone boson, the dilaton, resulting from the spontaneous breaking of scale symmetry. In addition light pseudoscalar bosons (axions) are expected in this class of models. We show that dynamical generation of fermion masses in these theories and the existence of a dilaton lead to unacceptably high axion masses. Therefore a dynamical fermion mass generation mechanism and a dilaton cannot coexist in a large class of such gauge theories.

  8. Autoimmune pancreatitis exhibiting multiple mass lesions.

    Science.gov (United States)

    Shiokawa, Masahiro; Kodama, Yuzo; Hiramatsu, Yukiko; Kurita, Akira; Sawai, Yugo; Uza, Norimitsu; Watanabe, Tomohiro; Chiba, Tsutomu

    2011-09-01

    Our case is a first report of autoimmune pancreatitis with multiple masses within the pancreas which was pathologically diagnosed by endoscopic ultrasound-guided fine needle aspiration and treated by steroid. The masses disappeared by steroid therapy. Our case is informative to know that autoimmune pancreatitis sometimes exhibits multiple masses within the pancreas and to diagnose it without unnecessary surgery.

  9. Autoimmune Pancreatitis Exhibiting Multiple Mass Lesions

    Directory of Open Access Journals (Sweden)

    Masahiro Shiokawa

    2011-09-01

    Full Text Available Our case is a first report of autoimmune pancreatitis with multiple masses within the pancreas which was pathologically diagnosed by endoscopic ultrasound-guided fine needle aspiration and treated by steroid. The masses disappeared by steroid therapy. Our case is informative to know that autoimmune pancreatitis sometimes exhibits multiple masses within the pancreas and to diagnose it without unnecessary surgery.

  10. IMPACT OF MASS MEDIA ON ELECTORAL PARTICIPATION

    OpenAIRE

    Ion MOCANU; Reviewer: Vladimir BLAJCO

    2013-01-01

    In the article is reflected the trust of the population in different types of mass information sources, is analysed the activity of the mass media in the electoral period, is established the influence of mass media on the population and its capacity to mobilize the electoral participation

  11. Impact of mass media on electoral participation

    OpenAIRE

    Mocanu Ion

    2013-01-01

    In the article is reflected the trust of the population in different types of mass information sources, is analysed the activity of the mass media in the electoral period, is established the influence of mass media on the population and its capacity to mobilize the electoral participation

  12. The mass of the Milky Way

    NARCIS (Netherlands)

    Kuijken, K; Bender, T; Renzini, A

    2003-01-01

    The Mass distribution of the Galaxy is reasonably well understood. Out to a radius of at least 200kpc, the enclosed mass increases roughly linearly with radius at about 10(10)M(circle dot) per kpc. The inner mass distribution is inconsistent with what we know to be present in stars and gas. Recent e

  13. Leptogenesis models and neutrino mass constraints

    Indian Academy of Sciences (India)

    T Hambye

    2006-10-01

    Through leptogenesis, baryogenesis could have the same origin as neutrino masses. We review the various ways of implementing the leptogenesis mechanism. Emphasis is put on the conditions which, in order that this mechanism works, need to be fulfilled by the neutrino masses as well as by the heavy state masses.

  14. Peptide Mass Fingerprinting of Egg White Proteins

    Science.gov (United States)

    Alty, Lisa T.; LaRiviere, Frederick J.

    2016-01-01

    Use of advanced mass spectrometry techniques in the undergraduate setting has burgeoned in the past decade. However, relatively few undergraduate experiments examine the proteomics tools of protein digestion, peptide accurate mass determination, and database searching, also known as peptide mass fingerprinting. In this experiment, biochemistry…

  15. Nutritional interventions to preserve skeletal muscle mass

    NARCIS (Netherlands)

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is

  16. Cosmo MSW effect for mass varying neutrinos

    CERN Document Server

    Hung, P Q; Hung, Pham Quang; P\\"as, Heinrich

    2003-01-01

    We consider neutrinos with varying masses which arise in scenarios relating neutrino masses to the dark energy density in the universe. We point out that the neutrino mass variation can lead to level crossing and thus a cosmo MSW effect, having dramatic consequences for the flavor ratio of astrophysical neutrinos and the composition of the relic neutrino background.

  17. Imaging mass spectrometry of polymeric materials

    NARCIS (Netherlands)

    Klerk, L.A.

    2009-01-01

    Imaging mass spectrometry (MS) is a technique that makes images of molecular distributions at surfaces based on mass spectral information. At a range (typically a raster) of positions, mass spectra are measured from the surface giving a characteristic fingerprint for the material that is present at

  18. Diversity in Mass Communication Theory Courses.

    Science.gov (United States)

    Lasorsa, Dominic L.

    2002-01-01

    Shows how prominent mass communication theories can be employed to further knowledge of diversity-related issues. Provides examples of how diversity-related issues can be addressed in mass communication theory courses. Concludes that, by definition, mass communication must take into account diversity. (PM)

  19. Einstein Never Approved of Relativistic Mass

    Science.gov (United States)

    Hecht, Eugene

    2009-01-01

    During much of the 20th century it was widely believed that one of the significant insights of special relativity was "relativistic mass." Today there are two schools on that issue: the traditional view that embraces speed-dependent "relativistic mass," and the more modern position that rejects it, maintaining that there is only one mass and it's…

  20. Mass Communication Instruction in the Secondary School.

    Science.gov (United States)

    Fletcher, James E.; Surlin, Stuart H.

    The steady increase of mass communication instruction in secondary schools has resulted from the demands by educators and the public for programs to help students cope with the impact and potential of mass media. This book describes the status and potential of mass communication instruction in secondary schools. Following an introductory chapter…

  1. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Chastagner, P.

    2001-08-01

    This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

  2. 10 CFR 150.11 - Critical mass.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Critical mass. 150.11 Section 150.11 Energy NUCLEAR... OFFSHORE WATERS UNDER SECTION 274 Exemptions in Agreement States § 150.11 Critical mass. (a) For the purposes of this part, special nuclear material in quantities not sufficient to form a critical mass...

  3. ISOLTRAP pins down masses of exotic nuclides

    CERN Document Server

    Blaum, Klaus; Beck, D; Bollen, G; Brodeur, M; Delahaye, P; George, S; Guenaut, C; Herfurth, F; Herlert, Alexander; Kellerbauer, A G; Kluge, H J; Lunney, M D; Mukherjee, M; Rodríguez, D; Schwarz, S; Schweikhard, L; Yazidjian, C

    2005-01-01

    The mass of radionuclides contribute to a variety of fundamental studies including tests of the weak interaction and the standard model. The limits of mass measurements on exotic nuclides have been extended considerably by the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. Recent ISOLTRAP measurements are summarized and current technical improvements are outlined.

  4. 14 CFR 23.659 - Mass balance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 23.659 Section 23.659 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Surfaces § 23.659 Mass balance. The supporting structure and the attachment of concentrated mass...

  5. 14 CFR 29.659 - Mass balance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 29.659 Section 29.659... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.659 Mass balance. (a) The rotor... flutter at any speed up to the maximum forward speed. (b) The structural integrity of the mass...

  6. 14 CFR 27.659 - Mass balance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Mass balance. 27.659 Section 27.659... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.659 Mass balance. (a) The rotors... flutter at any speed up to the maximum forward speed. (b) The structural integrity of the mass...

  7. Low-Mass Diffraction at the LHC

    CERN Document Server

    Jenkovszky, Laszlo; Lämsä, Jerry; Orava, Risto

    2011-01-01

    The expected resonance structure for the low-mass single diffractive states from a Regge-dual model elaborated paper by the present authors in a previous is predicted. Estimates for the observable low-mass single diffraction dissociation (SDD) cross sections and efficiencies for single diffractive events simulated by PYTHIA 6.2 as a function of the diffractive mass are given.

  8. Decay constants from twisted mass QCD

    CERN Document Server

    Dimopoulos, P; Michael, C; Simula, S; Urbach, C

    2008-01-01

    We present results for chiral extrapolations of the mass and decay constants of the rho meson. The data sets used are the nf=2 unquenched gauge configurations generated with twisted mass fermions by the European Twisted Mass Collaboration. We describe a calculation of three decay constants in charmonium and explain why they are required.

  9. Nutritional interventions to preserve skeletal muscle mass

    NARCIS (Netherlands)

    Backx, Evelien M.P.

    2016-01-01

    Muscle mass is the main predictor for muscle strength and physical function. The amount of muscle mass can decline rapidly during periods of reduced physical activity or during periods of energy intake restriction. For athletes, it is important to maintain muscle mass, since the loss of muscle is as

  10. Acquisition of HPLC-Mass Spectrometer

    Science.gov (United States)

    2015-08-18

    31-Jan-2015 Approved for Public Release; Distribution Unlimited Final Report: Acquisition of HPLC -Mass Spectrometer The views, opinions and/or findings...published in peer-reviewed journals: Final Report: Acquisition of HPLC -Mass Spectrometer Report Title The acquisition of the mass spectrometer has been a

  11. New schemes of static mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Baisanov, O.A. [Military Institute of Air Defense Forces, Aktobe (Kazakhstan); Doskeyev, G.A. [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan); Spivak-Lavrov, I.F., E-mail: baisanov@mail.ru [Aktobe State University named after K. Zhubanov, Aktobe (Kazakhstan)

    2011-07-21

    Different possibilities to increase the 'quality', or Q-quantity, of static mass spectrometers by expanding the ion beam before it enters the magnetic field are analyzed. The design of mass spectrometers using a cone-shaped achromatic prism is discussed. Different variants of achromatic mass spectrometers using electrostatic prisms and sector magnetic fields are also considered.

  12. Mass Determination of New Particle States

    CERN Document Server

    Serna, Mario

    2008-01-01

    We study theoretical and experimental facets of mass determination of new particle states. Assuming supersymmetry, we update the quark and lepton mass matrices at the grand unification scale accounting for threshold corrections enhanced by large tan beta. From the hypothesis that quark and lepton masses satisfy a classic set of relationships suggested in some Grand Unified Theories (GUTs), we predict tan beta needs to be large, and the gluino's soft mass needs to have the opposite sign to the wino's soft mass. Existing tools to measure the phase of the gluino's mass at upcoming hadron colliders require model-independent, kinematic techniques to determine the masses of the new supersymmetric particle states. We discuss the current techniques to determine the mass of invisible particles. We review the transverse mass kinematic variable M_{T2} and the use of invariant-mass edges to find relationships between masses. Next, we introduce a new technique to add additional constraints between the masses of new partic...

  13. Mass distributions of a macromolecular assembly based on electrospray ionization mass spectrometric masses of the constituent subunits

    Indian Academy of Sciences (India)

    Leonid Hanin; Brian Green; Franck Zal; Serge Vinogradov

    2003-09-01

    Macromolecular assemblies containing multiple protein subunits and having masses in the megadalton (MDa) range are involved in most of the functions of a living cell. Because of variation in the number and masses of subunits, macromolecular assemblies do not have a unique mass, but rather a mass distribution. The giant extracelular erythrocruorins (Ers), ∼ 3.5 MDa, comprized of at least 180 polypeptide chains, are one of the best characterized assemblies. Three-dimensional reconstructions from cryoelectron microscopic images show them to be hexagonal bilayer complexes of 12 subassemblies, each comprised of 12 globin chains, anchored to a subassembly of 36 nonglobin linker chains. We have calculated the most probable mass distributions for Lumbricus and Riftia assemblies and their globin and linker subassemblies, based on the Lumbricus Er stoichiometry and using accurate subunit masses obtained by electrospray ionization mass spectrometry. The expected masses of Lumbricus and Riftia Ers are 3.517 MDa and 3.284 MDa, respectively, with a possible variation of ∼ 9% due to the breadth of the mass distributions. The Lumbricus Er mass is in astonishingly good agreement with the mean of 23 known masses, 3.524 ± 0.481 MDa.

  14. Study of node and mass sensitivity of resonant mode based cantilevers with concentrated mass loading

    Science.gov (United States)

    Zhang, Kewei; Chai, Yuesheng; Fu, Jiahui

    2015-12-01

    Resonant-mode based cantilevers are an important type of acoustic wave based mass-sensing devices. In this work, the governing vibration equation of a bi-layer resonant-mode based cantilever attached with concentrated mass is established by using a modal analysis method. The effects of resonance modes and mass loading conditions on nodes and mass sensitivity of the cantilever were theoretically studied. The results suggested that the node did not shift when concentrated mass was loaded on a specific position. Mass sensitivity of the cantilever was linearly proportional to the square of the point displacement at the mass loading position for all the resonance modes. For the first resonance mode, when mass loading position xc satisfied 0 xc xc ≤ l. Mass sensitivity did not change when concentrated mass was loaded at the rigid end. This work can provide scientific guidance to optimize the mass sensitivity of a resonant-mode based cantilever.

  15. Teaching English through Mass Media

    Directory of Open Access Journals (Sweden)

    Vilma Tafani

    2009-03-01

    Full Text Available This article aims at analyzing the importance of using Mass Media in the classroom and finding the ways how to use Printed and Audio-visual Media. It is the result of an in-depth study, surveys and questionnaires thus trying to make the ideas in this article more trustworthy. It is based not only on the literature review but also on long personal experience. It is a brief description of some practical examples and some tips for novice teachers. Further more, this article tends to deal with some of the key issues of using media in the classroom. Here are included some of the findings of my research work on a post-doctorate Fulbright Program in 2001. The following issues are open for discussion: the importance of Media in general and in education in particular; Media are persuasive and pervasive, newspapers, magazines, radio, television and internet in the classroom, etc.

  16. Splenosis simulating an intrahepatic mass

    Institute of Scientific and Technical Information of China (English)

    晁明; 徐宏伟

    2004-01-01

    Splenosis is the autotransplantation of splenic tissue that usually follows traumatic rupture of the spleen. Splenic implants may be seeded within or beyond the peritoneal cavity.1 The most frequent locations of splenosis in the descending order are the serosal surface of the small intestine, the greater omentum, parietal peritoneum, surface of the large intestine, mesentery, undersurface of the diaphragm and the thorax.1,2 However, intrahepatic splenosis is very rare. We recently encountered a patient in whom results of ultrasonography (US) and computed tomography (CT) revealed an intrahepatic mass that consisted of ectopic splenic tissue. To our knowledge, this is the fifth report of ectopic splenic tissue in the liver in the English-language literature. We present the imaging findings of the splenic implants in the liver and discuss the diagnosis and its practical significance.

  17. Design for Mass User Involvement

    DEFF Research Database (Denmark)

    Vianello, Giovanna; Tan, Adrian

    as it creates a closer relationship to customers as well as creating the best possibilities for reducing impact of products on our natural environment. This new way of organizing the development process in collaboration with users holds many opportunities, but also challenges for companies and researchers. We...... be broadly adopted by the masses of people in the next century. Design methods are powerful tools to create solutions that fulfill the needs of people and improve their lives. Based on emerging trends in design and development as well as projecting current trends in the world today, we propose a new design...... formalism for the future in 2030 that is suited for a high tech, global manufacturing company. The design formalism involves the user throughout the design process and involves the company in the entire lifecycle of its products. It is believed that this approach will give companies a competitive advantage...

  18. Cosmic Ray Energetics and Mass

    CERN Document Server

    Baylon cardiel, J L; Wallace, K C; Anderson, T B; Copley, M

    The cosmic-ray energetics and mass (CREAM) investigation is designed to measure cosmic-ray composition to the supernova energy scale of 10$^{15}$ eV in a series of ultra long duration balloon (ULDB) flights. The first flight is planned to be launched from Antarctica in December 2004. The goal is to observe cosmic-ray spectral features and/or abundance changes that might signify a limit to supernova acceleration. The particle ($\\{Z}$) measurements will be made with a timing-based charge detector and a pixelated silicon charge detector to minimize the effect of backscatter from the calorimeter. The particle energy measurements will be made with a transition radiation detector (TRD) for $\\{Z}$ > 3 and a sampling tungsten/scintillator calorimeter for $\\{Z}$ $\\geq$1 particles, allowing inflight cross calibration of the two detectors. The status of the payload construction and flight preparation are reported in this paper.

  19. Predatory violence during mass murder.

    Science.gov (United States)

    Meloy, J R

    1997-03-01

    A case of mass murder by a 35-year old male is reported. Following a week of separation from his spouse and temporary loss of custody of his son, the subject went to his wife's worksite and murdered her and the store manager, wounded a passerby in a car, and murdered a police officer arriving on the scene. Weapons used were a .32 caliber revolver, a 9-mm pistol, a 7.62-mm assault rifle, and a .50-caliber rifle. The fact pattern of the case is shown to be quite consistent with a predatory mode of aggression-violence that is planned, purposeful, emotionless, and not preceded by autonomic arousal. The forensic importance of considering mode of violence, whether predatory or affective, independently of psychiatric diagnosis, is emphasized.

  20. The mass media and disasters

    Science.gov (United States)

    Rogers, E. M.

    1990-01-01

    Past investigations by myself and others on the role of the mass media in disasters indicate that news people typically find themselves in situations of uncertainty, ambiguity, and conflicting information; the communication and transportation services that these people use in covering a story become inoperative. However, the media are expected to make sense of the disaster situation almost immediately. the difficulties of doing so were reflected by the ABC Goodyear Blimp footage of the collapsed Nimitz Freeway in Oakland, California, broadcast nationally on the evening of October 17, 1989. The televised picture showed the disastrous results of the Loma Prieta earthquake, but for an hour or more the announcer could not correctly identify what was being shown. He did not seem to realize that the upper deck of the freeway had collapsed on the lower deck, crushing vechiles and people. 

  1. Tractors, Mass and Weyl Invariance

    CERN Document Server

    Gover, A R; Waldron, A

    2008-01-01

    Deser and Nepomechie established a relationship between masslessness and rigid conformal invariance by coupling to a background metric and demanding local Weyl invariance, a method which applies neither to massive theories nor theories which rely upon gauge invariances for masslessness. We extend this method to describe massive and gauge invariant theories using Weyl invariance. The key idea is to introduce a new scalar field which is constant when evaluated at the scale corresponding to the metric of physical interest. This technique relies on being able to efficiently construct Weyl invariant theories. This is achieved using tractor calculus--a mathematical machinery designed for the study of conformal geometry. From a physics standpoint, this amounts to arranging fields in multiplets with respect to the conformal group but with novel Weyl transformation laws. Our approach gives a mechanism for generating masses from Weyl weights. Breitenlohner--Freedman stability bounds for Anti de Sitter theories arise na...

  2. A rare epididymal mass: Leiomyoma

    Directory of Open Access Journals (Sweden)

    Tufan Cicek

    2014-04-01

    Full Text Available Leiomyoma is a benign smooth muscle tumor. It rarely rises from epididymal structures and usually is encountred in adults. The patient, who had undergone total epididymectomy for right scrotal mass at another center, was diagnosed with Epididymal Leiomyoma. He was admitted to our clinic for further evaluation and follow up. The previous eididymectomy specimens obtained and refered to our pathology department for confirmation of diagnosis. Microscopy revealed a benign neoplastic lesion, consisting of spindle cells. Which form interlacing bundels.Mitotic figures and tumor necrosis was not. Observed. The previous diagnosis is confirmed as the tumor showed immunohistochemical smooth muscule actin and Desmin posivity Whereas S-100 was not expressed with in the tumoral cells. This case report also overviews epididymal leiomyoma with recent literature findings. [Cukurova Med J 2014; 39(2.000: 399-402

  3. Coronal Mass Ejections travel time

    Science.gov (United States)

    Braga, Carlos Roberto; Souza de Mendonça, Rafael Rodrigues; Dal Lago, Alisson; Echer, Ezequiel

    2017-10-01

    Coronal mass ejections (CMEs) are the main source of intense geomagnetic storms when they are earthward directed. Studying their travel time is a key-point to understand when the disturbance will be observed at Earth. In this work, we study the CME that originated the interplanetary disturbance observed on 2013/10/02. According to the observations, the CME that caused the interplanetary disturbance was ejected on 2013/09/29. We obtained the CME speed and estimate of the time of arrival at the Lagrangian Point L1 using the concept of expansion speed. We found that observed and estimated times of arrival of the shock differ between 2 and 23 hours depending on method used to estimate the radial speed.

  4. Mass loss estimates for Cepheid variables

    Science.gov (United States)

    Deasy, H. P.; Wayman, P. A.

    1986-03-01

    Pulsation theory and the theory of stellar evolution yield estimates for Cepheid masses which disagree to different extents depending, for instance, on the adopted calibration of the period-luminosity relation. For example, Schmidt's (1984) distance scale (revised after redetermining the distance moduli of open clusters with Cepheids) finds the pulsation to be less than the evolutionary masses. Since the beat and bump masses are consistent with the pulsation masses in this scheme, it seems that the evolutionary models used, which have neglected mass loss, are in need of revision.

  5. Small Neutrino Masses: Another Anthropic principle aspect?

    CERN Document Server

    Sivaram, C; O, Kiren

    2016-01-01

    This year's Physics Nobel prize for the discovery of neutrino oscillations which resolved the problem of the missing solar neutrinos and the atmospheric muon neutrinos implies that at least one of the three neutrino species has a tiny mass. The neutrino oscillations measure the mass difference squared, and the individual neutrino masses have yet to be accurately ascertained. Particle theory has so far not given a predictive picture for neutrino masses. Here we propose that the anthropic principle may be relevant, as it is frequently invoked to understand other aspects of the universe, including the precise values of fine structure constant or nuclear coupling constant or even the proton-electron mass ratio.

  6. Quark ACM with topologically generated gluon mass

    Science.gov (United States)

    Choudhury, Ishita Dutta; Lahiri, Amitabha

    2016-03-01

    We investigate the effect of a small, gauge-invariant mass of the gluon on the anomalous chromomagnetic moment (ACM) of quarks by perturbative calculations at one-loop level. The mass of the gluon is taken to have been generated via a topological mass generation mechanism, in which the gluon acquires a mass through its interaction with an antisymmetric tensor field Bμν. For a small gluon mass ( ACM at momentum transfer q2 = -M Z2. We compare those with the ACM calculated for the gluon mass arising from a Proca mass term. We find that the ACM of up, down, strange and charm quarks vary significantly with the gluon mass, while the ACM of top and bottom quarks show negligible gluon mass dependence. The mechanism of gluon mass generation is most important for the strange quarks ACM, but not so much for the other quarks. We also show the results at q2 = -m t2. We find that the dependence on gluon mass at q2 = -m t2 is much less than at q2 = -M Z2 for all quarks.

  7. Caecal tumour masquerading as an appendicular mass

    Directory of Open Access Journals (Sweden)

    Martha Nixon

    2011-12-01

    Full Text Available Appropriate management of appendix mass is based on an accurate diagnosis of the underlying pathology. This is a report of a complex patient presenting with an appendix mass, whose surgery was deferred due to severe comorbidities and who later died from severe metastatic disease. A 65-year-old lady presented with right iliac fossa pain and a mass. She was treated for an appendix mass initially and when the mass failed to resolve after four weeks, she was thoroughly investigated for the possibility of a tumour. Severe co-morbities had a significant impact on her management as definitive surgery was delayed. She represented 10 months after the initial admission with small bowel obstruction and died of metastatic caecal cancer. Management of appendix mass must entail a careful approach to investigating and treatment with emphasis on early intervention if the mass does not resolve promptly. This will avoid delayed diagnosis, treatment and a detrimental impact on prognosis.

  8. On the Origin of Elementary Particle Masses

    CERN Document Server

    Hansson, Johan

    2012-01-01

    The oldest enigma in fundamental particle physics is: Where do the observed masses of elementary particles come from? Inspired by observation of the empirical particle mass spectrum we propose that the masses of elementary particles arise solely due to the self-interaction of the fields associated with a particle. We thus assume that the mass is proportional to the strength of the interaction of the field with itself. A simple application of this idea to the fermions is seen to yield a mass for the neutrino in line with constraints from direct experimental upper limits and correct order of magnitude predictions of mass separations between neutrinos, charged leptons and quarks. The neutrino interacts only through the weak force, hence becomes light. The electron interacts also via electromagnetism and accordingly becomes heavier. The quarks also have strong interactions and become heavy. The photon is the only fundamental particle to remain massless, as it is chargeless. Gluons gain mass comparable to quarks, ...

  9. Bulk disk resonator based ultrasensitive mass sensor

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Davis, Zachary James

    2009-01-01

    In the framework of developing an innovative label-free sensor for multiarrayed biodetection applications, we present a novel bulk resonator based mass sensor. The sensor is a polysilicon disk which shows a Q-factor of 6400 in air at 68.8 MHz, resulting in mass resolutions down in the femtogram...... range. The sensor has been characterized in terms of sensitivity both for distributed mass detection, performing six consecutive depositions of e-beam evaporated Au, and localized mass detection, depositing approximately 7.5 pg of Pt/Ga/C three times consecutively with a Focused Ion Beam system....... The sensor has an extremely high distributed mass to frequency shift sensitivity of 60104 Hzcm2/¿g and shows a localized mass to frequency sensitivity up to 4405 Hz/pg with a localized mass resolution down to 15 fg. The device has been fabricated with a new microfabrication process that uses only two...

  10. Theoretical reevaluations of black hole mass -- bulge mass relation - I. Influences of the seed black hole mass

    CERN Document Server

    Shirakata, Hikari; Okamoto, Takashi; Makiya, Ryu; Ishiyama, Tomoaki; Matsuoka, Yoshiki; Nagashima, Masahiro; Enoki, Motohiro; Oogi, Taira; Kobayashi, Masakazu A R

    2016-01-01

    We show influences of the mass of seed black holes on black hole mass -- bulge mass relation at z ~ 0 by using a semi-analytic model of galaxy formation combined with large cosmological N-body simulations. We constrain our model to reproduce observed properties of galaxies at z ~ 0. Similar to other semi-analytic models, we place a seed black hole immediately after a galaxy forms. When we set the seed black hole mass to 10^5 M_sun, we find that the model result becomes inconsistent with recent observational results of black hole mass -- bulge mass relation for dwarf galaxies. Namely, the model predicts that bulges with ~ 10^9 M_sun harbor black holes more massive than observed. On the other hand, when we employ seed black holes with 10^3 M_sun or randomly choose their masses in the range of 10^{3-5} M_sun, the black hole mass -- bulge mass relation obtained from these models are consistent with observational results including dispersions. We find that to obtain more stringent restrictions of the mass of seed ...

  11. THE RELATIONSHIP BETWEEN MASS OF NEWLY HATCHED INDIVIDUALS AND COCOON MASS IN LUMBRICID EARTHWORMS

    DEFF Research Database (Denmark)

    Bruus, Marianne; Bjerre, Arne

    1991-01-01

    Earthworm cocoons from laboratory cultures were collected and their mass was determined. When hatched, the mass of the young worms was found. Cocoon mass and the mass of hatchlings varied considerably within species. The hygromass of newly hatched earthworms was found to correlate linearly...

  12. Octet baryon mass splittings from up-down quark mass differences

    CERN Document Server

    Horsley, R; Nakamura, Y; Pleiter, D; Rakow, P E L; Schierholz, G; Zanotti, J M

    2012-01-01

    Using an SU(3) flavour symmetry breaking expansion in the quark mass, we determine the QCD component of the neutron-proton, Sigma and Xi mass splittings of the baryon octet due to up-down (and strange) quark mass differences. Provided the average quark mass is kept constant, the expansion coefficients in our procedure can be determined from computationally cheaper simulations with mass degenerate sea quarks and partially quenched valence quarks. Full details and numerical results are given in ref 1.

  13. Constraining the lightest neutrino mass and mee from general lepton mass matrices

    Indian Academy of Sciences (India)

    Samandeep Sharma; Gulsheen Ahuja; Manmohan Gupta

    2016-02-01

    Despite spectacular advances in fixing the neutrino mass and mixing parameters through various neutrino oscillation experiments, we still have little knowledge about the magnitudes of some vital parameters in the neutrino sector such as the absolute neutrino mass scale, effective Majorana mass mee measured in neutrinoless double beta decay. In this context, the present work aims to make an attempt to obtain some bounds for mee and the lightest neutrino mass using fairly general lepton mass matrices in the Standard Model.

  14. Low thermal mass liquid chromatography.

    Science.gov (United States)

    Gu, Binghe; Cortes, Hernan; Luong, Jim; Pursch, Matthias; Eckerle, Patric; Mustacich, Robert

    2009-02-15

    A novel technique, low thermal mass liquid chromatography (LTMLC), is introduced in this study. The use of an LTM assembly that utilizes the principle of resistive wire heating and a temperature sensor to accurately deliver unprecedented heating (up to 1800 degrees C/min) or cooling (100 to approximately 200 degrees C/min) rates is reported. With the use of packed microcolumns (heat transfer from the assembly to the mobile phase was obtained. A systematic investigation was conducted to study the performance of the LTMLC technique. Both isocratic and gradient mobile phase conditions were used. For temperature control, isothermal, temperature-increasing, and temperature-decreasing gradients were applied. Three model mixtures, two of which containing neutral and acidic analytes and the other containing neutral, acidic, and basic analytes, were used to study the effect of temperature on elution time, resolution, column efficiency, and selectivity. It was found that the LTMLC experimental setup delivered reliable temperature control, as evidenced by linear van't Hoff plots for neutral and acidic compounds. The effect of temperature on the elution of basic analytes yielded nonlinear van't Hoff plots, explaining the dramatic selectivity changes observed for bases with changes in column temperature. Column efficiency generally increased with the increase in column temperature in the range of 25 to approximately 75 degrees C and decreased in the range of 75 to approximately 150 degrees C at a fixed column flow rate (3 microL/min), when extra column band broadening was taken into account. The increase in efficiency upon the increase in column temperature in the low temperature range was mainly due to the decreased mass transfer term resulting from increased analyte diffusivity. However, under even higher temperatures, the longitudinal diffusion dominated band broadening, explaining the decrease in column efficiency upon a further increase in column temperature. Resolution

  15. Relation of Body's Lean Mass, Fat Mass, and Body Mass Index With Submaximal Systolic Blood Pressure in Young Adult Men.

    Science.gov (United States)

    Prasad, Vivek K; Drenowatz, Clemens; Hand, Gregory A; Lavie, Carl J; Sui, Xuemei; Demello, Madison; Blair, Steven N

    2016-02-01

    We examined the association of body composition and body mass index (BMI) with submaximal systolic blood pressure (SSBP) among young adult men. The analysis included 211 men with BMI between 20 and 35 kg/m(2). Total lean mass and fat mass were measured using dual x-ray absorptiometry and lean mass percentage was calculated from the total lean mass. Fat mass index (FMI) and BMI were calculated using height and weight (total fat mass and total weight, respectively) measurements. SSBP was measured at each stage of a graded exercise test. Quintiles of lean mass percentage, FMI, and BMI were created with quintile 1 the lowest and quintile 5 the highest lean mass percentage, FMI, and BMI. Compared with men in lean mass percentage quintile 1, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5 at 6, 8, and 10 minutes. Compared with men in FMI quintile 5, those in quintiles 2, 3, and 4 had significantly lower SSBP, whereas there was no significant difference in SSBP between quintile 1 and 5. SSBP among men in lean mass percentage quintile 5 and FMI quintile 1 were still less than lean mass percentage quintile 1 and FMI quintile 5, respectively. There were no significant differences in SSBP across BMI quintiles 1 to 4 but a significantly higher SSBP in quintile 5 compared with quintiles 1 to 4. In conclusion, there was a J-curve pattern between SSBP and components of body composition, whereas, a linear relation between SSBP and BMI.

  16. Absorption mode FTICR mass spectrometry imaging.

    Science.gov (United States)

    Smith, Donald F; Kilgour, David P A; Konijnenburg, Marco; O'Connor, Peter B; Heeren, Ron M A

    2013-12-03

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here, we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image, and then, these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode "Datacubes" for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

  17. A REVIEW ON MASS SPECTROMETRY DETECTORS

    Directory of Open Access Journals (Sweden)

    Khatri Neetu

    2012-10-01

    Full Text Available Mass spectrometry is an analytical technique for "weighing" molecules. Obviously, this is not done with a conventional scale or balance. Instead, mass spectrometry is based upon the principle of the motion of a charged particle that is called an ion, in an electric or magnetic field. The mass to charge ratio (m/z of the ion affects particles motion. Since the charge of an electron is known, the mass to charge ratio (m/z is a measurement of mass of an ion. Mass spectrometry research focuses on the formation of gas phase ions, and detection of ions. Detectors in mass spectrometer detect the separated ions according to m/z ratio. The main disadvantages of conventional detectors are very low sensitivity and poor detection efficiency. Detectors are of a great interest to a wide range of industrial, military, environmental and even biological applications. In recent developments, molecules of higher mass can also be detected and enhanced lifetime under the less than ideal environments typically encountered in mass spectrometers. This review deals in detail about the design, working and principle of mass spectrometric detectors and their recent developments.

  18. Back to the Future: Estimating Initial Globular Cluster Masses from their Present Day Stellar Mass Functions

    CERN Document Server

    Webb, Jeremy J

    2015-01-01

    We use N-body simulations to model the 12 Gyr evolution of a suite of star clusters with identical initial stellar mass functions over a range of initial cluster masses, sizes, and orbits. Our models reproduce the distribution of present-day global stellar mass functions that is observed in the Milky Way globular cluster population. We find that the slope of a star cluster's stellar mass function is strongly correlated with the fraction of mass that the cluster has lost, independent of the cluster's initial mass, and nearly independent of its orbit and initial size. Thus, the mass function - initial mass relation can be used to determine a Galactic cluster's initial total stellar mass, if the initial stellar mass function is known. We apply the mass function - initial mass relation presented here to determine the initial stellar masses of 33 Galactic globular clusters, assuming an universal Kroupa initial mass function. Our study suggests that globular clusters had initial masses that were on average a factor...

  19. N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes

    Science.gov (United States)

    Baumgardt, H.

    2016-10-01

    We have determined the masses and mass-to-light ratios of 50 Galactic globular clusters by comparing their velocity dispersion and surface brightness profiles against a large grid of 900 N-body simulations of star clusters of varying initial concentration, size and central black hole mass fraction. Our models follow the evolution of the clusters under the combined effects of stellar evolution and two-body relaxation allowing us to take the effects of mass segregation and energy equipartition between stars self-consistently into account. For a subset of 16 well observed clusters we also derive their kinematic distances. We find an average mass-to-light ratio of Galactic globular clusters of =1.98 ± 0.03, which agrees very well with the expected M/L ratio if the initial mass function (IMF) of the clusters was a standard Kroupa or Chabrier mass function. We do not find evidence for a decrease of the average mass-to-light ratio with metallicity. The surface brightness and velocity dispersion profiles of most globular clusters are incompatible with the presence of intermediate-mass black holes (IMBHs) with more than a few thousand M⊙ in them. The only clear exception is ω Cen, where the velocity dispersion profile provides strong evidence for the presence of a ˜40,000 M⊙ IMBH in the centre of the cluster.

  20. N -body modelling of globular clusters: masses, mass-to-light ratios and intermediate-mass black holes

    Science.gov (United States)

    Baumgardt, H.

    2017-01-01

    We have determined the masses and mass-to-light ratios of 50 Galactic globular clusters by comparing their velocity dispersion and surface brightness profiles against a large grid of 900 N-body simulations of star clusters of varying initial concentration, size and central black hole mass fraction. Our models follow the evolution of the clusters under the combined effects of stellar evolution and two-body relaxation allowing us to take the effects of mass segregation and energy equipartition between stars self-consistently into account. For a subset of 16 well-observed clusters, we also derive their kinematic distances. We find an average mass-to-light ratio of Galactic globular clusters of =1.98 ± 0.03, which agrees very well with the expected M/L ratio if the initial mass function (IMF) of the clusters was a standard Kroupa or Chabrier mass function. We do not find evidence for a decrease in the average mass-to-light ratio with metallicity. The surface brightness and velocity dispersion profiles of most globular clusters are incompatible with the presence of intermediate-mass black holes (IMBHs) with more than a few thousand M⊙ in them. The only clear exception is ω Cen, where the velocity dispersion profile provides strong evidence for the presence of a ˜40 000 M⊙ IMBH in the centre of the cluster.