1,725,723 research outputs found
HR 7250 ve HR 7545 yıldızlarının kimyasal bolluk analizi
No full textBu çalışmada, literatürde kapsamlı tayfsal bolluk analizi mevcut bulunmayan HR 7250 ve HR 7545 yıldızlarının kimyasal bolluk dağılımları incelendi. Yıldızların tayfları TÜBİTAK Ulusal Gözlemevi’nde RTT 150 Teleskobuna bağlı Coude Echelle tayfçekeri ile elde edildi. Her iki yıldızın yüksek çözünürlüklü tayfları 3920 - 9150 Å dalgaboyu aralığını kapsamaktadır. Gözlemsel verilerin indirgemeleri IRAF program ile gerçekleştirildi. BINMAG programı kullanılarak tayflarda yer alan soğurma çizgileri tanımlandı. Her çizgiye ait atomik tür, merkezi dalgaboyu ve eşdeğer genişlik değerleri ölçüldü. Atmosfer modelleri ATLAS9 (Kurucz 1993) kodu yardımıyla üretildi. Her iki yıldızın atmosfer parametreleri olan etkin sıcaklık, yüzey çekim ivmesi ve mikro türbülansları belirlendikten sonra ayrıntılı kimyasal bolluk analizi gerçekleştirildi. HR 7250 yıldızı için elde edilen değerler: Te = 8200 K, log g = 3.20 ve mikrotürbülans hızı 3.4 km sn-1’dır. Dönme hızı (v sini) 35 ± 5 km sn-1 olarak belirlendi. C, Mg, Si, Ca, Sc, Ti, Cr, Fe, Ni, Zn ve Ba elementlerinin bollukları hesaplandı. HR 7545 yıldızı için elde edilen değerler: Te = 8800 K, log g = 3.4 ve mikrotürbülans hızı 2.6 km sn-1 ’dır. Dönme hızı (v sini) ise 12 ± 3 km sn-1 olarak belirlendi. C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Sr, Y, Zr, ve Ba elementlerinin bollukları belirlendi.Kimyasal bolluk dağılımları göz önünde bulundurarak yıldızların kimyasal bakımda ne tür yıldızlar oldukları tartışıldı. Buna göre, HR 7545 yıldızında gözlenen bollukların Am türünden yıldızlara ilişkin bolluklarla, HR 7250 yıldızındakilerin ise normal A türünden yıldızlarda gözlenenlerle uyumlu olduğu bulundu. Yıldızlar için hesaplanan ışınım gücü ve etkin sıcaklık kullanılarak yıldızların HR diyagramı üzerindeki konumları belirlendi. Salasnich vd. (2000)evrim yolu modelleri kullanarak yıldızların kütleleri ve Bressan vd. (2012) izokronlar yardımıyla ise yaşları hesaplandı. HR 7250 yıldızının kütlesi 2.30 ± 0.09 Mʘ ve HR 7545 yıldızının ise 2.60 ± 0.09 Mʘ olarak hesaplandı. HR 7250 yıldızının yaşı 730 ± 60 milyon yıl ve HR 7545 yıldızının ise 560 ±40 milyon yıl olarak belirlendi. AbstractIn this study, the chemical abundance distribution of HR 7250 and HR 7545 was investigated. These two stars detailed abundance analysis are neglected in the literature. High resolution spectra covering 3920-9150Å of the optical spectral region were obtained with Coude Echelle Spectrograph attached to the RTT 150 telescope at the TÜBİTAK National Observatory. The echelle spectra reduction procedures were performed with IRAF. The spectral lines were measured using BINMAG. Atomic species, central wavelength, and equivalent width were determined for each spectral line. Model atmospheres were generated using the ATLAS9 code (Kurucz 1993). After the determination of the atmosphere parameters, which are effective temperature, surface gravity, and microturbulence, detailed chemical abundance analysis for both stars were performed. The adopted values of HR 7250 are Teff = 8200 K, log g = 3.2 and microturbulent velocity was calculated as 3.4 km s-1. Rotational velocity was measured as 35 ± 5 km s-1. The abundance of C, Mg, Si, Ca, Sc, Ti, Cr, Fe, Ni, Zn, and Ba were calculated for HR 7250. For HR 7545 the adopted values are Teff = 8800 K, log g = 3.4 and microturbulent velocity was calculated as 2.6 km s-1. Rotational velocity was measured as 12 ± 3 km s-1. C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Zn, Sr, Y, Zr, and Ba abundances were calculated for HR 7545. These stars chemical distribution showed that HR 7545 is likely to be an Am star while HR 7250 is a normal A type star. The luminosity and effective temperatures of the stars pinpointed their positions on the HR diagram. The evolution tracks from Salasnich et al. (2000) and isochrones of Bressan et al. (2012) were also plotted on the HR diagram to determine the masses and ages of the stars. The mass was calculated as 2.30 ± 0.09 Mʘ for HR 7250 and 2.60 ± 0.09 Mʘ for HR 7545. The age of HR 7250 star was evaluated as 730 ± 60 million years and 560 ±40 million years for HR 7545
Agricoltura 4.0 / 4.0 Agriculture. Trattore 7250 TTV Agrotron / 7250 TTV Agrotron tractor
No full textIn 2024, the 7250 TTV Agrotron series tractor designed by Fabrizio Giugiaro and manufactured by Bergamo-based company Same-Deutz-Fahr,won the XXIII Compasso d'Oro. A significant recognition since the prize went to an agricultural vehicle intended for essentially technical use: it highlighted the completely unique investment in terms of research and development that denoted an unprecedented design-oriented approach for this specific production sector
MAD in campo al lavoro. Deutz-Fahr 7250 TTV, potente sul campo, fluido in trasporto
No full textDeutz-Fahr 7250 TT
DS-7250, a Diacylglycerol Acyltransferase 1 Inhibitor, Enhances Hepatic Steatosis in Zucker Fatty Rats via Upregulation of Fatty Acid Synthesis
No full text Diacylglycerol acyltransferase 1 (DGAT1) catalyzes the final step in triglyceride synthesis. Since Dgat1-/- mice fed a high-fat diet (HFD) are resistant to hepatic steatosis, DGAT1 inhibitors are expected to have antifatty liver effects. To evaluate the hepatic effects of DS-7250, a selective DGAT1 inhibitor, vehicle or 10 mg/kg of DS-7250 was administered orally to male Fisher 344 (F344) and Zucker fatty (ZF) rats fed a standard diet or HFD for 14 or 28 days. ZF rats showed slight hepatic steatosis regardless of feeding conditions. DS-7250 exacerbated hepatic steatosis in ZF rats fed an HFD compared with the vehicle control. Hepatic steatosis did not occur in F344 rats fed an HFD, in which systemic exposures of DS-7250 were comparable to those in ZF rats. There was a higher expression of genes involved in lipid uptake and fatty acid synthesis in ZF rats compared to F344 rats under HFD conditions. DS-7250 upregulated key genes involved in de novo lipogenesis, which causes hepatic steatosis independently of DGAT1, in ZF rats fed an HFD compared with the vehicle control. These data suggest that ZF rats were more susceptible to hepatic steatosis due to their genetic characteristics and DS-7250 exacerbated hepatic steatosis independently of DGAT1. </jats:p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Крупнейшие голоценовые извержения вулкана Авачинский на Камчатке (этап 7250-3700 14С лет назад)
No full textРеконструированы хронология, динамика и параметры семи крупнейших извержений андезитового этапа 1Ав 7250-3700 14С-лет назад (л.н.) вулкана Авачинский на Камчатке, начавшегося после >2000-летнего периода относительного покоя. Описаны их ювенильные (андезитовая пирокластика) и резургентные продукты, оценен геолого-геоморфологический эффект. Самое мощное извержение (объем продуктов 8-10 км3) было 7250, последующие - 5700 (3*0,34 км3), 5600 (3*0,4 км3), 5500 (1,34 км3), 5000 (0,5 км3), 4500 (>1,1 км3), 4000 ( 0,6 км3) 14С-л.н. Среди изверженных продуктов преобладала тефра, пирокластические потоки имели место лишь при извержениях 5500 и 5000 л.н. Предполагается, что большинство извержений могло давать кислотные пики разной интенсивности в Гренландском ледниковом щите
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effect of four trace elements on Paenibacillus polymyxa Pp-7250 proliferation, activity and colonization in ginseng
No full textAbstract Trace elements are essential nutrients for the growth of microorganisms and play an important role in their proliferation. Hence, the purpose of this paper is to explore the optimal C and N sources for large-scale culture of Paenibacillus polymyxa, and to screen trace elements that can promote their proliferation and improve the activity. First, the concentration of Paenibacillus polymyxa Pp-7250, the number of spores were used as evaluation index. It was found that the four trace elements Cu2+, Fe2+, Mn2+, and Zn2+ could promote the proliferation of Paenibacillus polymyxa at their optimal concentrations. Next, when using wheat starch as carbon source and soybean meal as nitrogen source, it was most suitable for large-scale culture. Finally, field experiments were carried out, and it was discovered that the combination of four trace elements plus the wheat soybean meal group could significantly improve the disease prevention, growth promotion ability of Pp-7250 and its colonization in ginseng. Moreover, the ability of Pp-7250 to transform ginseng roots and leaf saponins were also significantly improved. The group also affected the rhizosphere bacterial community of ginseng and the number showed a significant promotion or inhibition
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