oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2017 ( 438 )

2016 ( 948 )

2015 ( 13697 )

2014 ( 17797 )

自定义范围…

匹配条件: “Vanya M. Naydenova” ,找到相关结果约399688条。
列表显示的所有文章,均可免费获取
第1页/共399688条
每页显示
Heavy metals content in soil near non1ferous metals production facility and domestic wastes landfill in the area of Kardzhali town
Rositsa E. Chilingirova,Jeni N. Staykova,Iliana G. Velcheva,Vanya M. Naydenova
Ecologia Balkanica , 2011,
Abstract: The predominant soil types in the region of Kardzhali are maroon forest soils highly leached and poorly podzolized. Most of the soils have medium to high erosion ability IIIII degree, and the pH is neutral to slightly alkaline (77,8). Few are weak and moderate acidic pH (6,75). Soils are mostly shallow to moderately deep, poor in nutrients. In the region of Kardzhali main pollutants are heavy metals from miningprocessing and metallurgical business activities of “GorubsoKardzhali” AD and LZC AD, Kardzhali. In the paper are presented results of soil contamination mainly with lead, cadmium, copper and zinc, showing concentrations of lead in the soil over the MAC, according to Ordinance № 3/2008 Standards for acceptable content of harmful substances in soil.
A Novel Synthesis of Nanostructured ZnO via Thermal Oxidation of Zn Nanowires Obtained by a Green Route  [PDF]
Adriana Veloso Maciel, Wagner da Nova Mussel, Vanya Márcia Duarte Pasa
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.15041
Abstract: ZnO nanowires were synthesised in a green and novel, two-step process: (1) the production of Zn nanowires by carbo-thermal reduction of a mixture of ZnO/biopitch (Eucalyptus sp. tar pitch) at 900°C for 1 h in a quartz tube placed in an electric furnace in a N2 atmosphere and (2) the oxidation of the as-prepared Zn nanowires in air at 300°C for 3 h and 6 h and at 400°C for 3 h. The structural properties and phase compositions of the oxidised samples were studied by X-ray diffraction (XRD), and the morphologies were investigated by scanning electron microscopy (SEM). The XRD results demonstrated the formation of ZnO phase, as the main product. The oxidised products exhibited good crystallinity. Maximal conversion of the Zn nanowires into ZnO nanowires (99%) resulted from oxidation of the sample for 3 h in air at 300°C. The formation of ZnO was also confirmed by Fourier transform infrared (FTIR) spectroscopy.
(E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene
Aurelien Crochet,Katharina M. Fromm,Vanya Kurteva,Liudmil Antonov
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811010932
Abstract: The title compound, C21H16N2O, has an E-conformation about the diazene N=N bond. It is reasonably planar with the phenyl ring being inclined to the mean plane of the anthracene moiety [planar to within 0.077 (3) ] by 6.43 (10)°. The crystal structure is stabilized by C—H...π and weak π–π interactions [centroid–centroid distances of 3.7192 (16) and 3.8382 (15) ], leading to the formation of two-dimensional networks stacking along [001] and lying parallel to (110).
Codes for error detection, good or not good
Irina Naydenova,Torleiv Klove
Mathematics , 2005,
Abstract: Linear codes for error detection on a q-ary symmetric channel are studied. It is shown that for given dimension k and minimum distance d, there exists a value \mu(d,k) such that if C is a code of length n >= \mu(d,k), then neither C nor its dual are good for error detection. For d >> k or k << d good approximations for \mu(d,k) are given. A generalization to non-linear codes is also given.
ECF Bleaching with Molybdenum Activated Acid Peroxide and its Impact on Eucalyptus Pulp Properties and Effluent Quality  [PDF]
Marco Ant?nio Bandeira Azevedo, Vanya Márcia Duarte Pasa, Hannu H?m?l?inen, Ann Honor Mounteer, Rubens Chaves de Oliveira, Jorge Luiz Colodette
Natural Resources (NR) , 2011, DOI: 10.4236/nr.2011.21008
Abstract: Acid hydrogen peroxide catalyzed with molybdenum (PMo stage) is effective to decrease pulp kappa number and potentially minimize chlorine dioxide demand in subsequent ECF bleaching. This study aimed at developing cost-effective methods for applying PMo as the first stage bleaching for eucalyptus kraft pulp and evaluating their impact on pulp properties and effluent quality in relation to current ECF bleaching techniques. The PMo(EP)DP and A/PMo(EP)DP sequences proved to be most cost-effective for PMo stage application. The pulp properties and effluent quality derived from bleaching with these two sequences were compared with those of the conventional bleaching with the DHT(EP)DP sequence. The PMo(EP)DP sequence produced pulp of refinability and physical properties similar to that of the reference but the A/PMo(EP)DP one resulted in pulp of 20% lower refinability and 10% lower tearing strength. Untreated effluents of the PMo(EP)DP and A/PMo(EP)DP sequences presented similar COD, but lower AOX and color than the DHT(EP)DP effluents. None of the effluents exhibited acute toxicity. The effluents from the PMo(EP)DP sequence showed much lower BOD and BOD/COD ratio than that of the A/PMo(EP)DP one. All effluents were readily treated in bench-scale reactors, and achieved COD removal efficiencies of greater than 70%.
Allometry of the Duration of Flight Feather Molt in Birds
Sievert Rohwer,Robert E. Ricklefs,Vanya G. Rohwer,Michelle M. Copple
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.1000132
Abstract: We used allometric scaling to explain why the regular replacement of the primary flight feathers requires disproportionately more time for large birds. Primary growth rate scales to mass (M) as M0.171, whereas the summed length of the primaries scales almost twice as fast (M0.316). The ratio of length (mm) to rate (mm/day), which would be the time needed to replace all the primaries one by one, increases as the 0.14 power of mass (M0.316/M0.171 = M0.145), illustrating why the time required to replace the primaries is so important to life history evolution in large birds. Smaller birds generally replace all their flight feathers annually, but larger birds that fly while renewing their primaries often extend the primary molt over two or more years. Most flying birds exhibit one of three fundamentally different modes of primary replacement, and the size distributions of birds associated with these replacement modes suggest that birds that replace their primaries in a single wave of molt cannot approach the size of the largest flying birds without first transitioning to a more complex mode of primary replacement. Finally, we propose two models that could account for the 1/6 power allometry between feather growth rate and body mass, both based on a length-to-surface relationship that transforms the linear, cylindrical growing region responsible for producing feather tissue into an essentially two-dimensional structure. These allometric relationships offer a general explanation for flight feather replacement requiring disproportionately more time for large birds.
Allometry of the Duration of Flight Feather Molt in Birds
Sievert Rohwer ,Robert E. Ricklefs,Vanya G. Rohwer,Michelle M. Copple
PLOS Biology , 2009, DOI: 10.1371/journal.pbio.1000132
Abstract: We used allometric scaling to explain why the regular replacement of the primary flight feathers requires disproportionately more time for large birds. Primary growth rate scales to mass (M) as M0.171, whereas the summed length of the primaries scales almost twice as fast (M0.316). The ratio of length (mm) to rate (mm/day), which would be the time needed to replace all the primaries one by one, increases as the 0.14 power of mass (M0.316/M0.171 = M0.145), illustrating why the time required to replace the primaries is so important to life history evolution in large birds. Smaller birds generally replace all their flight feathers annually, but larger birds that fly while renewing their primaries often extend the primary molt over two or more years. Most flying birds exhibit one of three fundamentally different modes of primary replacement, and the size distributions of birds associated with these replacement modes suggest that birds that replace their primaries in a single wave of molt cannot approach the size of the largest flying birds without first transitioning to a more complex mode of primary replacement. Finally, we propose two models that could account for the 1/6 power allometry between feather growth rate and body mass, both based on a length-to-surface relationship that transforms the linear, cylindrical growing region responsible for producing feather tissue into an essentially two-dimensional structure. These allometric relationships offer a general explanation for flight feather replacement requiring disproportionately more time for large birds.
Exhibiting Arirang
Kunwook (Vanya) Lee
International Journal of Intangible Heritage , 2012,
Abstract: Arirang is best known as a type of Korean folk song. But it is more than just a simple folk song. It is a kind of cultural phenomenon that embodies people’s lives and everyday activities. The National Folk Museum of Korea recently curated a special exhibition about Arirang to reconsider the meaning of this song which so many Koreans take for granted. In the exhibition we presented both historical materials and everyday products related to Arirang, and we also introduced sound resources. These were not only recordings of the songs performed by professional singers, but also recordings of Arirang songs sung by ordinary people, documented region by region. We collected personal stories and accounts of what Arirang means, and these too were edited into audio-visual forms to be exhibited. Certain regional groups that co-operated in collecting materials for the exhibition were invited to give performances themselves. The performances by people who put their own experiences into the Arirang lyrics were especially popular with audiences. The exhibition was important for the future in that we gained new experience in utilising tangible and intangible materials possessed by communities which are transmitting a certain kind of intangible heritage.
YIELD OF ENERGY AND PROTEIN FROM GRAIN MAIZE HYBRIDS USING AGROTECHNICAL SYSTEM, OPTIMAL FOR THE CONDITIONS IN THE PLOVDIV REGION
VANYA DELIBALTOVA,Dimo PENKOV
Journal of Central European Agriculture , 2011,
Abstract: The yields of metabolizable energy for ducks and protein, so as the multiplication effect by different varieties of maize have been investigated. For the conditions in the Plovdiv region the hybrid PR35P12 had the highest yield of crude protein - 1368 kg/ha, and metabolizable energy – AME- 171,5 GJ/ha and TME – 181,3 GJ/ha. The highest multiplication effect (protein yield/crude protein applied by seed material) – showed hybrid PR35P12 - +403.3.
Symmetrical Acyclic Aryl Aldazines with Antibacterial and Antifungal Activity  [PDF]
Vanya B. Kurteva, Svilen P. Simeonov, Margarita Stoilova-Disheva
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.21001
Abstract: A series of 22 symmetrical acyclic aromatic aldazines were obtained and their qualitative antimicrobial activities were evaluated against 10 bacterial and 3 fungal species. The results demonstrated that the bi- and polycyclic aromatics studied are remarkably more active than benzaldazines. The latter possess antibacterial activities only, which were dramatically reduced by the introduction of substituents. The tests showed that the activities are strongly dependent on the type and position of the substituents and that the effects on antibacterial and antifungal activities are the opposite. 2-Naphtaldazine was significantly more active than its position isomer 1-naphthaldazine against Saccharomyces cerevisiae and Penicillium chrysogenum, whereas both compounds possess commensurable activities towards Candida tropicalis and the bacterial strains. From the other side, the presence of 4-hydroxy substituent in 1-naphthaldazine reduced the antibacterial and increased the antifungal activities, while the influence of 2-hydroxy group led to reversed results.
第1页/共399688条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.