3,358 research outputs found

    La crisis del sector eléctrico en california 2000–2001: reformas y desintegración vertical

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    El objetivo en este artículo es mostrar cómo se dio el proceso de desintegración vertical del sector eléctrico de California. Además de examinar el papel que desempeñó la regulación en este proceso y determinar los efectos de la reforma implementada en 1996 en este mercado. La crisis del mercado eléctrico en California finalizando la década de los noventa y principios de 2000, ha sido para muchas economía mundiales, un buen ejemplo de lo que no se debe hacer, dado el efecto negativo que esto tiene sobre la eficiencia económica.This paper seeks to analyze what factors determine the capital structure of the banking firms in Colombia. With this purpose, the existing literatura about the subject is reviewed and, assuming that the hypothesis of the existence of an optimal capital structure holds, an optimization model of a representative banking firm is implemented to observe how these factors affect the optimal capital structure. Additionally, a panel data model is run to contrast the theoretical results with the empirical evidence for the Colombian banking firms. Finally, some conclusions about the found results are postulated

    Multi-Sensor System For Level Measurements With Optical Fibres

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    A system for measuring liquid level in multiple tanks using optical fibre technology has been developed. The oil field service industry can benefit from this intrinsically safe technology. Plastic optical fibre (POF) sensor heads are excited by a 650 nm laser. Laser diodes are housed in ST connectors to obtain compact and rough prototypes and these connectors are also used in the fibre pigtails. Optical multiplexing is used to increase the measuring safety area. POF splitters and connectors are used to combine all the receiving sensor head fibres in a single one. Frequency division multiplexing is used to address each sensor head. The global system is controlled through a user friendly software application running in a PC connected to the system via an RS-232 port. A scalable prototype with a range greater than 2 meter, good linearity, better than 1.5% FS (full scale), high accuracy and resolution is developed using a unique lens to collimate and focus the light. Measurements are taken to validate the designs. Up to 8 sensor heads can be connected in the present implementation. But a greater number of sensors can be allocated with minor modifications in the electronics.Universidad Carlos III de MadridPublicad

    The Sustainable Management of Metals: An Analysis of Global Research

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    The objective of this study was to analyze research trends in the field of sustainable management of metals on a global level between 1993 and 2017. To do so, a bibliometric analysis was carried out on a total of 6967 articles. The results revealed the growing interest in this research field, particularly over the last five year-period during which 63% of all articles were published. The three journals in which most articles had been published were the Journal of Cleaner Production, ACS Sustainable Chemistry and Engineering, and Chemsuschem. The countries that published the most articles were China, the United States, India, Germany, and the United Kingdom. A sizeable network of collaboration has been established between countries for the joint publication of studies. The main lines of research have been focused on metal decontamination in water and soil, waste management oriented towards reuse and recycling, and the innovation of processes for cleaner and more efficient production. The results revealed the need for comprehensive studies that integrate different disciplines within the same analytical framework, and to promote research that contributes to the different dimensions of sustainability (environmental, economic, and social)

    Student Perception of the Use of a Blended-Learning Model to Improve Grammatical Competence

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    [EN]This is the presentation of the paper entitled “Student Perception of the Use of a Blended-Learning Model to Improve Grammatical Competence” in the TEEM 2015 International Conference held in Porto (Portugal) in October 7-9, 2015. The study focuses on learners’ perceptions for learning English grammar in the course of English Morphosyntax at graduate level at the Pontifical University of Salamanca. This course is offered via a blended instructional delivery mode. The study utilizes a quantitative method approach, using a survey conducted online. The survey is designed with Google Drive and is embedded into the virtual learning environment (VLE) as a common place for students’ participation. The learners’ high satisfaction towards the blended instructional delivery mode reveals that the model implemented provides a satisfying experience. Learners indicate that thanks to the E-activities presented in the VLE, they have improved their grammatical competence and are more aware of the rules of English Grammar.

    Exercises using a touchscreen tablet application improved functional ability more than an exercise program prescribed on paper in people after surgical carpal tunnel release: a randomised trial

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    Question: In people who have undergone surgical carpal tunnel release, do sensorimotor-based exercises performed on the touchscreen of a tablet device improve outcomes more than a conventional home exercise program prescribed on paper? Design: Randomised, parallel-group trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Participants: Fifty participants within 10 days of surgical carpal tunnel release. Intervention: Each participant was prescribed a 4-week home exercise program. Participants in the experimental group received the ReHand tablet application, which administered and monitored exercises via the touchscreen. The control group was prescribed a home exercise program on paper, as is usual practice in the public hospital system. Outcome measures: The primary outcome was functional ability of the hand, reported using the shortened form of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire. Secondary outcomes were grip strength, pain intensity measured on a 10-cm visual analogue scale, and dexterity measured with the Nine-Hole Peg Test. Outcomes were measured by a blinded assessor at baseline and at the end of the 4-week intervention period. Results: At Week 4, functional ability improved significantly more in the experimental group than the control group (MD –21, 95% CI –33 to –9) on the QuickDASH score (0 to 100). Although the mean estimates of effect on the secondary outcome also all favoured the experimental group, none reached statistical significance: grip strength (MD 5.6 kg, 95% CI –0.5 to 11.7), pain (MD –1.4 cm, 95% CI –2.9 to 0.1), and dexterity (MD –1.3 seconds, 95% CI –3.7 to 1.1). Conclusion: Use of the ReHand tablet application for early rehabilitation after carpal tunnel release is more effective in the recovery of functional ability than a conventional home exercise program. It remains unclear whether there are any benefits in grip strength, pain or dexterity. Trial registration: ACTRN12618001887268

    Analyzing job satisfaction from a gender point of view: empirical application with logit and probit models

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    La influencia que las características individuales del personal de una empresa ejercen sobre su nivel de satisfacción laboral ha sido ampliamente analizada en la literatura al respecto, dedicando una especial atención a la variable edad pero también al género como un elemento determinante de los niveles de satisfacción de los recursos humanos. En numerosas investigaciones se constata que las mujeres presentan un nivel superior de satisfacción al de los varones. El presente trabajo analiza la influencia del género sobre la satisfacción laboral sobre una muestra de 1.804 personas empleadas en centros de enseñanza concertada en Andalucía, confirmando este resultado. Asimismo, se revisan las diferencias entre varones y mujeres respecto a la influencia de otras variables sociodemográficas, del puesto y de la organización sobre la satisfacción con el trabajo, detectando diferencias notables entre ambos sexos en algunos aspectos como el estado civil, el nivel educativo o la presencia o no en cargos directivosThe influence that the individual characteristics of the personnel of a company exercise on their level of job satisfaction has been largely analyzed in specialized literature, dedicating more attention to the age but also to the gender like a determining element of the levels of satisfaction on human resources. Numerous investigations verify the fact that women present a superior level of satisfaction to the one belonging to males. This paper examines the influence of the gender on job satisfaction on a sample of 1,804 people working in private educational centres in Andalusia, confirming this result. Furthermore, it revises the differences between men and women considering the influence over job satisfaction of other sociodemographic characteristics as well as variables about the job and the organization, detecting remarkable differences between both sexes in some aspects like the marital status, the educational level or the presence in managerial position

    Density and reproductive characteristics of female brown bears in the Cantabrian Mountains, NW Spain

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    Here we present annual nearest-neighbour distances (as a proxy of density) between females with cubs-of-the-year (hereafter FCOY) and reproductive characteristics of brown bears Ursus arctos in the Cantabrian Mountains (NW Spain), from 1989 to 2017. FCOY nearest-neighbour distances and reproduction parameters of 19 focal females followed over several consecutive years (from 2004 to 2017) were obtained from bears inhabiting the western sector of the Cantabrian Mountains, where most of the bear population resides. In contrast, general reproductive characteristics were studied in the whole Cantabrian Mountains (western and eastern sectors together) on a sample of 362 litter sizes and 695 cubs. Mean nearest-neighbour distance between FCOY was 2559 ± 1222 m (range = 1305–4757 m). Mean litter size was significantly larger in the west (1.8 ± 0.2 cubs) than in the east (1.3 ± 0.6 cubs). Mean litter size for the whole of the Cantabrian Mountains was 1.6 ± 0.3 cubs. Litter sizes of one, two and three cubs represented 33.4, 56.1 and 10.5% of observed family groups, respectively. Interannual variations in litter size were not significant for both the western and the eastern areas. Mean cub mortality was 0.2 ± 0.5 cubs and did not vary among years. Cub mortality per litter size was 3.9% for one cub, 69.2% for two cubs and 26.9% for three cubs. Mean reproductive rate of the 19 focal females was 1.5 ± 0.6 cubs (n = 58 litters). Litter size of focal FCOY did not differ from the litter size obtained from systematic observations in the whole Cantabrian Mountains. During this period, cub mortality occurred in 24.1% of the 58 litters. Females usually bred every second year (average litter interval = 2.2 years). The estimated reproductive rate for the bear population was 0.7 young born/year/reproductive adult female
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