A non-destructive method for elliptical cracks identification in shafts based on wave propagation signals and genetic algorithms

Belén Muñoz-Abella,Lourdes Rubio,Patricia Rubio 국제구조공학회 2012 Smart Structures and Systems, An International Jou Vol.10 No.1

The presence of crack-like defects in mechanical and structural elements produces failures during their service life that in some cases can be catastrophic. So, the early detection of the fatigue cracks is particularly important because they grow rapidly, with a propagation velocity that increases exponentially, and may lead to long out-of-service periods, heavy damages of machines and severe economic consequences. In this work, a non-destructive method for the detection and identification of elliptical cracks in shafts based on stress wave propagation is proposed. The propagation of a stress wave in a cracked shaft has been numerically analyzed and numerical results have been used to detect and identify the crack through the genetic algorithm optimization method. The results obtained in this work allow the development of an on-line method for damage detection and identification for cracked shaft-like components using an easy and portable dynamic testing device.

Move over? Feminist reading of academic writing on Kurdish women

Özlem Belçim Galip 이화여자대학교 한국여성연구원 2021 Asian Journal of Women's Studies(AJWS) Vol.27 No.4

Research on Kurdish women has burgeoned during the last decade, which is a positive sign of the growing interest regarding a highly marginalized population and region. However, most of these works contain theoretical and methodological inadequacies, fallacies and contradictory messages regarding the agency, or lack of it, of Kurdish women, along with an orientalist approach. Using feminist rhetorical criticism and discourse approaches, together with a focus on intersectionality, orientalism and postcolonial feminism, I examine some existing studies on Kurdish women and attempt to uncover the construction of and implications about Kurdish women. I also examine the degrees to which these studies promote narratives that uphold assumptions on gender and implicitly contribute to traditional ideologies of patriarchy and the stigma of being westernized. By demonstrating the significance of a plural model, which examines the lived realities of women, their negotiations and struggles, I urge a fresh approach to the discursive and contextual practice of scholarship on Kurdish women.

Management of large class II lesions in molars: how to restore and when to perform surgical crown lengthening?

Ana Belén Dablanca-Blanco,Juan Blanco-Carrión,Benjamín Martín-Biedma,Purificación Varela-Patiño,Alba Bello-Castro,Pablo Castelo-Baz 대한치과보존학회 2017 Restorative Dentistry & Endodontics Vol.42 No.3

The restoration of endodontic tooth is always a challenge for the clinician, not only due to excessive loss of tooth structure but also invasion of the biological width due to large decayed lesions. In this paper, the 7 most common clinical scenarios in molars with class II lesions ever deeper were examined. This includes both the type of restoration (direct or indirect) and the management of the cavity margin, such as the need for deep margin elevation (DME) or crown lengthening. It is necessary to have the DME when the healthy tooth remnant is in the sulcus or at the epithelium level. For caries that reaches the connective tissue or the bone crest, crown lengthening is required. Endocrowns are a good treatment option in the endodontically treated tooth when the loss of structure is advanced.

Use of supercritical methanol/carbon dioxide mixtures for biodiesel production

María Belén García-Jarana,Jezabel Sánchez-Oneto,Juan Ramón Portela,Lourdes Casas,Casimiro Mantell,Enrique Martínez de la Ossa 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.8

The use of supercritical conditions for the production of biodiesel from both vegetables oils and waste-oils may be of great industrial interest because it can be carried out without those catalysts necessary in the conventional transesterification process, therefore avoiding a complex separation between the product and the catalyst. However, the use of supercritical alcohol requires higher operating temperatures and pressures. In this work, CO2 was added to the reaction mixture in order to reduce the operating conditions (temperature, pressure and molar ratio of alcohol to vegetable oil). The novelty of using CO2 may have two advantages: a possible combination of supercritical CO2 extraction of the oil and its subsequent transesterification reaction without CO2 depressurization, and a reduction of the supercritical temperature and pressure of the mixture. The effects of temperature (280-350 oC), pressure (140-280 bar), methanol- to-oil molar ratio (20-30), CO2-to-methanol molar ratio (0.05-0.2) and residence time (0-45minutes) on the yield of methyl esters (biodiesel) were studied in a batch reactor, obtaining in all cases a relatively low increase in the yield when CO2 was present in the medium. The yields of biodiesel were tested with three vegetable oils used as model compounds (palm, sunflower and borage), obtaining similar results.

Phytochemical Attributes of Four Conventionally Extracted Medicinal Plants and Cytotoxic Evaluation of Their Extracts on Human Laryngeal Carcinoma (HEp2) Cells

Ana Belščak-Cvitanović,Ksenija Durgo,Arijana Bušić,Jasna Franekić,Draženka Komes 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.2

The bioactive composition and cytotoxic and antioxidative/prooxidative effects of four medicinal plants: yarrow (Achillea millefolium L.), hawthorn (Crataegus oxyacantha L.), ground ivy (Glechoma hederacea L.), and olive (Olea europea L.) on human laryngeal carcinoma cell line (HEp2) were investigated. Water extracts of these plants obtained by infusion, maceration, and decoction were characterized for their polyphenol content and antioxidant capacity. Based on the extraction efficiency of polyphenols, the final extracts were obtained whose polyphenolic profile, polysaccharides, mineral content, and cytoprotective activities were determined. The overall highest content of polyphenols and antioxidant capacity was determined in hawthorn, followed by yarrow and ground ivy, and the lowest in olive leaves extract. Phytochemical screening revealed the presence of phenolic acids, as the most abundant bioactive compounds, followed by flavonoids, flavons, and flavonols. All examined medicinal plants reduced the cell viability and reactive oxygen species formation in a dose- and time-dependent manner. Ground ivy and yarrow containing a high content of phenolic acids and polysaccharides were more efficient to decrease the cell survival when compared to olive leaf and hawthorn. Experiments confirmed the importance of polyphenolic composition rather than content of investigated plants and revealed a relationship between the polyphenolic and polysaccharide contents and antioxidant/prooxidant characters of medicinal plants.

The value of sub-national data: The dynamics of contentious politics in Nepal

Johannes Vüllers,Belén González 한국외국어대학교 국제지역연구센터 2020 International Area Studies Review Vol.23 No.3

Over the last decade, a renewed interest in the empirical analysis of contentious politics has led to significant improvements in the quality and quantity of data. The related wave of research has thus turned to analysis of the dynamics of contentious politics from a comparative perspective. Unfortunately, these studies use country level datasets for their analysis, creating a mismatch between the original actor-based theoretical framework and the empirical conceptualization of contentious collective action. We discuss the conceptual challenges this theoretical-empirical gap generates and highlight how contentious dynamics can be studied with a bottom-up subnational approach. To do so, we present a new fine-grained dataset of contentious collective action in post-conflict Nepal (2007 to 2010). We descriptively show how this type of data can help us improve our understanding of repertoires of contentious politics. This paper highlights the relevance of gathering information on active organizations to study the inherent dynamics of contentious politics.

Alternative Woods for Aging Distillates -An Insight into Their Phenolic Profiles and Antioxidant Activities

Roberto Rodríguez Madrera,Belén Suárez Valles,Yolanda Diñeiro García,Paula del Valle Argüelles,Anna Picinelli Lobo 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.4

Work has commenced on the study and characterization of wood native species (oak, chestnut,cherry, alder, ash, and beech), employed to a minor extent in enology, for their application in the elaboration of distillates. To this end, furanic and low molecular weight phenol compounds, total phenolic content, and antioxidant activity in alcoholic extracts by maceration of wood chips at 2 toasting levels were studied. Significant differences between samples, technologically relevant, were due both to species and toasting time. Furthermore, extracts showed interesting antioxidant activities equivalent in some cases to than those reported for alcoholic beverages aged in wood.

A Low-Voltage High-Performance CMOS Feedforward AGC Circuit for Wideband Wireless Receivers

Juan Pablo Alegre,Belén Calvo,Santiago Celma 한국전자통신연구원 2008 ETRI Journal Vol.30 No.5

Wireless communication systems, such as WLAN or Bluetooth receivers, employ preamble data to estimate the channel characteristics, introducing stringent settling-time constraints. This makes the use of traditional closed-loop feedback automatic gain control (AGC) circuits impractical for these applications. In this paper, a compact feedforward AGC circuit is proposed to obtain a fastsettling response. The AGC has been implemented in a 0.35 μm standard CMOS technology. Supplied at 1.8 V, it operates with a power consumption of 1.6 mW at frequencies as high as 100 MHz, while its gain ranges from 0 dB to 21 dB in 3 dB steps through a digital word. The settling time of the circuit is below 0.25 μs.

Antioxidant Capacity and Polyphenolic Content of Blueberry (Vaccinium corymbosum L.) Leaf Infusions

J. Piljac-Žegarac,A. Belščak,A. Piljac 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.3

Antioxidant capacity and polyphenolic content of leaf infusions prepared from six highbush blueberry cultivars (Vaccinium corymbosum L.), one wild lowbush blueberry cultivar (Vaccinium myrtillus L.), and one commercially available mix of genotypes were determined. In order to simulate household tea preparation conditions, infusions were prepared in water heated to 95°C. The dynamics of extraction of polyphenolic antioxidants were monitored over the course of 30 minutes. Extraction efficiency, quantified in terms of the total phenol (TP) content, and antioxidant capacity of infusions, evaluated by the ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, were compared with cultivar type and extraction time. The 30-minute infusions exhibited the highest TP content and antioxidant capacity according to all three assays. Wild blueberry infusion had the highest TP content (1,879mg/L gallic acid equivalents [GAE]) and FRAP values (20,050μM). The range of TP values for 30-minute infusions was 394–1,879mg/L GAE with a mean of 986mg/L GAE across cultivars; FRAP values fell between 3,015 and 20,050μM with a mean of 11,234μM across cultivars. All 30-minute infusions exhibited significant scavenging capacity for DPPH• and ABTS•+ radicals, comparable to different concentrations of catechin, gallic acid, and 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid. Overall, tested infusions showed significant reducing capacity as well as radical scavenging potential, which places blueberry leaf tea high on the list of dietary sources of antioxidants.

The indigenous bioculture of the Pungalá parish of Ecuador an approach to their culinary and medicinal heritage

Zurita-Gallegos Ronald Mauricio,Bastidas-Arauz María Belén,Saeteros-Hernandez Angélica María,Chávez Renato Hernán Herrera,Cardenas-Moyano María Yadira 한국식품연구원 2024 Journal of Ethnic Foods Vol.11 No.6

The food and culinary heritage with medicinal uses are a fascinating field that combines history, culture, and health through food. Over the centuries, various cultures have developed knowledge and practices related to the use of specific ingredients and culinary preparations with medicinal properties. In the Pungalá parish in Ecuador, these generational knowledge and traditions form a valuable biocultural heritage that helps us understand the close relationship between food and traditional medicine. Through qualitative and documentary research, interviews and community workshops are conducted to gather information using different techniques. Among the findings regarding the food and culinary heritage of Pungalá are extinct culinary traditions, as well as important culinary techniques and processes that play a role in nutrition and medicine, valuing traditional and ancestral knowledge as part of their culture. The inventory includes 22 plants used in Andean medicine and 38 preparations, including beverages, porridges, stews, soups, and wrapped dishes that become an integral part of everyday routines, dietary habits, and festive traditions. It is concluded that this knowledge constitutes a valuable food and culinary heritage, and its biocultural is based on ancestral knowledge of the healing properties of local plants and foods, contributing to the health and identity of the community. Measures should be taken to preserve and promote this heritage in the face of current challenges.