OALib Journal期刊

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匹配条件: “Yordanka G. Hristeva” ,找到相关结果约189312条。
Bryophytes in Protected Territories of Plovdiv City (Bulgaria): Preliminary Species List and First Data of Air Pollution Monitoring
Yordanka G. Hristeva,Gana M. Gecheva,Lilyana D. Yurukova
Ecologia Balkanica , 2011,
Abstract: The study comprises preliminary results of survey on bryophyte diversity in protected areas in the city of Plovdiv and biomonitoring urban air pollution with moss Hy p n u m c u p r e s s i f o r m e. The finding of 2 species with conservational value (Isothecium myosuroides Brid., Grimmia crinita Brid.) suggests that surveys of bryophyte biodiversity across protected landscapes should be continued. The determined concentrations of 15 elements in Hypnum cupressiforme revealed no serious pollution by airborne heavy metals and toxic elements contaminants. The applied biomonitor and PCA distinctly separated anthropogenic influenced city sites and reference one.
The trophic plasticity of genus phelipanche pomel (orobanchaceae) in bulgaria Trofichna plastichnost na rod phelipanche pomel (orobanchaceae) v bulgaria
Journal of Central European Agriculture , 2013, DOI: 10.5513/jcea01/14.1.1183
Abstract: New data about the natural parasitism of Phelipanche ramosa (L) Pomel, P. mutelii (Shultz) Pomel, P. oxyloba, P. arenaria and P. purpurea in Bulgaria are collected. The information for the hosts describes 46 new trophic systems with species from the families: Brassicaceae, Solanaceae, Fabaceae, Asteraceae, Apiaceae, Poaceae, Lamiaceae, Scrophulariaceae, Chenopodiaceae, Caryophyllaceae, Araliaceae, Euphorbiaceae, Geraniaceae, Dioscoreaceae and Verbenaceae. The samples are collected outside the crop fields, far from the known host crops, from different parts of the country. Some of the registered hosts are new for Bulgaria. The voucher specimens with physical connection to the hosts are deposited in the Herbarium of The Agricultural University - Plovdiv (SOA). The collected data suggest that genus Phelipanche is represented by two trophic groups according to the known sections. Sect. Phelipanche unites the polyphags P. ramosa, P. oxyloba and P. mutelii. Sect. Arenariae consist oligophags - P. arenaria and P. purpurea.
Multinational corporations and foreign investors in CEE: Western European multinationals in the CEE agro-food industry: The cases of Nestle, Unilever and InBev
Chobanova Yordanka
Zbornik Matice Srpske za Drustvene Nauke , 2008, DOI: 10.2298/zmsdn0824031c
Abstract: Using Systems of Innovation Approach (SI) and International Business (IB) literature, this paper analyzes the level of embeddedness of Multi-national Enterprises (MNEs) in Central and Eastern Europe (CEE). MNEs are discussed as they link the host country economy with the global economy by their regional and global networks. The expansion and successful embeddedness of West European multinational firms is crucial for the industrial integration of CEECs into the EU. The focus of the study is on the largest food processing com-panies, which invested in the region - namely Nestlé Unilever and InBev. The paper discusses the motives of investment and the entry strategies of food MNEs, outlines their contribution to the local development and stresses on the national actors as forces to embedded foreign direct investment (FDI). The paper discovered that EU membership facilitated the processes of global reorganizations of Nestlé, Unilever and InBev in CEE. All the three MNEs object of this research closed partially or completely plants all over CEE (and Western Europe). Hence, in a liberal trade regime it is very difficult to talk about long-term embeddedness of MNEs. It seems that the global strategies of the companies and the size of the market are the factor, which pre-determines the level of embeddedness of food MNEs in a certain economy and not so much the national actors and institutions. .
Cultivation of Microalgae Monoraphidium sp., in the Plant Pilot the Grand Valle Bio Energy, for Biodiesel Production  [PDF]
Gisel Chenard Díaz, Yordanka Reyes Cruz, René González Carliz, Rosa C. Vitorino de Paula, Donato A. Gomes Aranda, Marcellus A. G. Dario, Gustavo Saraiva Marass, Nelson C. Furtado
Natural Science (NS) , 2015, DOI: 10.4236/ns.2015.77040
Abstract: At present, Brazil imports approximately 11 billion liters/year of diesel. With the interruption of the works in the new Petrobras refineries, the projection is that by 2025 this volume will increase to 24.2 billion liters of diesel/year. In this sense, the biodiesel factory Grand Valle Bio Energy Ltda., located in the state of Rio de Janeiro, in conjunction with the FAPERJ makes some investments in technology development for the cultivation and use of microalgae as an alternative raw material in the production of biodiesel. Based on arguments previously said, this work presents the results of the microalgae cultivation Monoraphidium sp. in photobioreactors the pilot plant of the company. The installation with an area of 120 m2 is included with 2 open photobioreactors of type falling film (20 m × 1 m), with a cascade of 18mm and capacity of 4000 L. The lineage cultivated is selected from previous ecophysiological studies that are identified as promising for biodiesel production by having a high potential for the production of lipids. This lineage is maintained at collection of the stock of cultures Laboratory of Green Technologies of the School of Chemistry/ UFRJ. The cultivation was performed in means ASM-1 (Gorham et al., 1964), initial pH 8.0, with aeration and circulation average of 8 hours a day during 19 days. The culture was started with an inoculum of 1 × 107 cel/ml. The lipid production was determined in two phases of growth: on day 4 (exponential phase) and 15 day (stationary phase). For the determination and quantification of lipid content, two different methods were assessed for a sample of biomass, submitted to the same processes the separation and drying. The results showed the methodology of Bligh & Dyer with modifications as the most efficient in extracting lipids. The total lipid content of the biomass Monoraphidium sp. was 30.58%. The growth rate varied between 0.74 ± 0.01 and 0.68 ± 0.02.
Yordanka Ts. Tasheva
Petroleum and Coal , 2011,
Abstract: All regulations agencies /EPA, EU/ have issued regulations for reducing the level of sulfur in gasolineand diesel fuel. In order to comply with these new regulations, essentially all domestic refineries areforced to install new fuel desulphurization processes. Well-known hydro treating processes are commerciallyavailable. These hydro treating processes operate at relatively high pressures and use significant amountsof hydrogen. Therefore, these processes require a significant capital investment and have high operatingcosts. In addition, most gasoline desulphurization processes based on hydrogenation degrade the qualityof the gasoline.In this paper is considered the possibility to use an extraction and oxidative methods as purifying methodsfrom sulfur compounds and naphtalene from model mixtures.
Neurotoxoplasmosis. Presentación de un caso Neurotoxoplasmosis. A case report
Juan de la Concepción Torres Marín,Juan Torres Ruiz,Yordanka Romero Gómez,Marvelia Díaz Calzada
Revista de Ciencias M??dicas de Pinar del R?-o , 2012,
Abstract: Se realizó un estudio de caso de una paciente de 45 a os de edad y con antecedentes de ser seropositiva al VIH, que había comenzado hacía 10 días con agitación y un aumento de volumen de los miembros inferiores, adenopatías y fiebre diaria; todo esto unido a un decaimiento marcado. Después de varios días de ingresada comenzó con vómitos. Se le realizaron los exámenes complementarios, que en su mayoría fueron normales, sólo presentó la hemoglobina ligeramente baja (10,5g/L), leucopenia a predominio de polimorfos, y al examen físico, dolor a la palpación y movilización tanto activa como pasiva, así como un edema de ambos miembros inferiores; también se apreció gran irritabilidad. Se le realizó una tomografía axial computarizada conluyendo se trataba de una neurotoxoplasmosis. Los autores revisan el tema y ofrecen sus experiencias en el manejo del caso. It was carried out the presentation of a 45 year-old patient with antecedents of being seropositive to the HIV and that had begun 10 days ago with agitation and increase of the inferior members' volume and daily fevers. All this together to a marked decline after several days of having entered began with vomits. They were carried out the complementary ones that were majority normal, it presented lightly low hemoglobin (105g/L), leucopenia to polimorfos prevalence, and to the physical exam, the pain to the palpatión and mobilization so much active as passive, as well as the edema of both inferior members, great irritability, and a axial computaraizer tomographi was also appreciated that it concluded that it was a Neurotoxoplasmosis. The authors revise the topic and they narrate their experiences in the handling of the case.
Recent advances in Broomrapes research
Journal of BioScience and Biotechnology , 2012,
Abstract: Orobanchaceae (broomrapes) is a morphologically diverse family of predominantly herbaceous, parasitic plants. The majority of species are facultative or obligate root parasites that subsist on broad-leaf plants, thereby depleting them of nutrients, minerals and water. The taxonomy status of the family Orobanchaceae among other flowering plants is often subject of debate. They possess only a few morphological features suitable for taxonomy purposes and yet even they are quite changeable. The variability within the species is too high and hampers the attempts to create proper determination keys. During last two decades several molecular markers were used for reevaluate taxonomy, biodiversity and phylogenetic relationships within the family. Recent investigations supported by molecular taxonomy analyses have resulted in re-definition of Orobanchaceae family. According to this classification Orobanchaceae consists of 89 genera, containing 2061 species. On the Balkans the family Orobanchaceae is represented by 3 genera: Orobanche includes 25 species; Phelipanche comprises of 9 species and some putative hybrids; Diphelypaea occurs with single species, Diphelypaea boissieri, in Macedonia and Greece. Only a few recent studies based on modern methods took place during last decade. Their findings confirmed differences between Phelipanche and Orobanche genera, but raised new question about their internal structure. Several broomrape species parasitize important crops. They are widely spread in Bulgaria, Southern Europe, Russia, Middle East and Northern Africa. They cause losses in crop productivity estimated at hundreds of millions of dollars annually than affect the livelihoods of 100 million farmers. A wide variety of approaches have been explored to control broomrapes, but none have been found to be sufficiently effective and affordable. The new findings about their life cycle and the recent genomic project focused on sequences of Ph. aegyptiaca genome open new perspectives for management of the harmful broomrape species and for understanding of their biology and evolution as well.
Hydroesterification of Nannochloropsis oculata microalga’s biomass to biodiesel on Al2O3 supported Nb2O5 catalyst  [PDF]
Angel Almarales, Gisel Chenard, Roberto Abdala, Donato A. Gomes, Yordanka Reyes, Neyda Om Tapanes
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.44031
Abstract: Hydroesterification process has been presented biodiesel production from oil the green microalga Nannochloropsis oculata raw materials. Biodiesel studied in this work is the main product got from the hydroesterification of biomass the Nannochloropsis oculata and was obtained from esterification of fatty acid (product of a hydrolysis reaction) with methanol. It was used as catalyst the niobic acid pure and supported on δ-aluminum. The product was evaluated by gas chromatography and other analyses. The optimum conditions found in the conversion (%) for the hydrolysis reactions of the biomass (92.3%). Better results were observed in the algae concentration 20%, lead at 300?C with 20% of catalyst. For esterification of fatty acids of Nannochloropsis oculata (92.24%), were observed the molar ratio methanol: fat acid 3, lead at 200°C with 20% of catalyst supported.
Factores epidemiológicos en el embarazo ectópico
Rodríguez Morales,Yordanka; Altunaga Palacio,Margarita;
Revista Cubana de Obstetricia y Ginecolog?-a , 2010,
Abstract: objective: to know the incidence of major risk factors of ectopic pregnancy. methods: a clinical study was conducted on risk factor prevailing in appearance of ectopic pregnancy at "eusebio hernández" gynecology and obstetrics university hospital from january, 2005 to december, 2007. sample included 447 patients, admitted with the diagnosis of ectopic pregnancy confirmed by pathological anatomy. a survey was completed in each patient analyzing different variables: age, smoking, onset of first sexual intercourse, obstetric backgrounds, pelvic affections, contraceptives used. results: a higher incidence of ectopic pregnancies in 20-29 age group (15 %) was demonstrated. more than half of cases don't smoke (59.7.%). first sexual intercourses before 18 years had the higher percentage of ectopic pregnancies (67.1 %), birth and induced abortions showed the greater incidence (35.7.%). pelvic inflammatory disease accounted for 38.2 %, group using iuds had the greater percentage (28.4 %). conclusions: gage group with a greater risk of ectopic pregnancy was between 20-29 years. the higher number of ectopic pregnancy diagnoses was in patients with sexual intercourses before 18 years. pelvic inflammatory disease was present in a high percentage of cases.
Yana K. Koleva,Petko Petkov,Yordanka Tasheva
Petroleum and Coal , 2011,
Abstract: Thiophene is a tar component and is often present at sites contaminated by benzene that is one of the most widespread contaminants in soil and groundwater. Earlier research shows that thiophene is resistant to biological degradation, but it can be degraded cometabolically with benzene or other aromatic hydro-carbons as a primary substrate. This study summarises the available knowledge about the thiophene degradation (observed and predicted). This work considered the probable biodegradation of thiophene from petroleum spills under environment. The obtained results from the prediction of the biodegradation for the petroleum thiophene by the OECD (Q)SAR Application Toolbox system are restricted. Metabolites of the heterocyclic compound as thiophene based on observed microbial metabolism were not demonstrated, but six metabolites in the microbial metabolism simulator were predicted.

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