117 research outputs found
A uniform economic valuation methodology for solar photovoltaic applications competing in a utility environment
The question of how the economic benefits of weather-dependent electric generation technologies should be measured is addressed, with specific reference to dispersed, user-owned photovoltaic systems. The approach to photovoltaic R&D investment that has historically been practiced by the Federal Government is described in order to demonstrate the need for an economic value measure. Two methods presently in common
use, busbar energy costs and total systems costs, are presented and their strengths and weaknesses highlighted. A methodology is then presented which measures the "worth" of a system to a user and the implications of
this analysis for R&D investment are discussed. Finally, a simple simulation model of a photovoltaic residence is designed which
demonstrates the use of the suggested methodology
Tradeoff analysis for electric power planning in New England
The use of a multi-attribute trade-off analysis technique as a vehicle to provide information to a diverse group of electric industry interests can play a beneficial role for developing long-range strategies for the electric power sector. The advisory group/analysis team structure presented here allows different groups to evaluate multiple issues simultaneously, incorporating the range of supply and demand options, and future uncertainties characteristic of complex systems.The initial phase of such an Integrated Resource Planning project for New England electric power industry has identified that: significant gains in the areas of reliability and environmental emissions can be made by the introduction of new generating technologies; the recent emphasis on natural gas fired technologies should be matched by an effort to ensure adequate supplies of gas, and other effort to guard against fuel related vulnerabilities
Methodology and definition of solar photovoltaic planning regions
Prepared for the United States Dept. of Energy under Contract no. EX-76-A-01-2295, Task Order 37.There are in use at the present time at least 10 differently defined
sets of energy planning regions for the United States. This paper identifies
and describes the existing energy planning regions and discusses their intended
function. It then presents an argument for development of a set of solar
regions within the United States and discusses the criterion (climate, economics
and energy supply/demand) which are required for definition of such a set of regions.
The final two sections of the paper discuss a methodology two stage factor
analysis, for the definition of solar planning regions and the application of
that methodology to the definition of a set of seven planning regions for the
United States. Those regions so defined are: the Northeast (south as far as
Virginia); the south (west as far as Oklahoma and Kansas); the southwest
(including California and Nevada); the northwest (as far east as the Dakotas);
the midwest (stretching from Minnesota to Ohio) and individually the state of
Texas
Cost-Effective Comparison Between Two Anesthesia Techniques: Sevofluorane-Remifentanyl vs Isofluorane-Remifentanyl
Nos encontramos en la era de la optimización de costos, por lo que es necesario realizar estudios farmacoeconómicos para identificar la costo- efectividad de los anestésicos actuales. Metodología: este estudio prospectivo, cegado al paciente, comparó los costos directos, los tiempos de recuperación y satisfacción de 45 pacientes que se asignaron aleatoriamente a dos grupos de anestesia balanceada (grupo sevofluoraneremifentanil n = 24 o grupo isofluoraneremifentanil n = 21) que iban a ser sometidos a cirugías de otorrinolaringología. Resultados: los tiempos de recuperación temprana (apertura ocular, respuesta a comandos, extubación, orientación y salida de sala) fueron menores en el grupo ISO y tuvieron diferencia estadísticamente significativa. Se encontraron datos variables en los costos de adquisición de los halogenados gastados, que fueron menores para el isofluorane, lo cual hacía también menos costosos los insumos anestésicos durante las cirugías; sin embargo, los costos en la sala de cirugía, en recuperación y sala de ambulatorios y los costos totales no mostraron diferencias significativas. La satisfacción fue similar entre los dos grupos. Conclusiones: una técnica basada en sevofluorane-remifentanil no es más costo-efectiva que utilizar isofluorane-remifentanil para pacientes ambulatorios sometidos a cirugías de otorrinolaringología.We are in the of costs optimization era, reason why it is necessary to make pharmaceutical economics studies to identify the costeffectiveness of today’s anesthetics. Methods: this prospective study, blinded to the patient, compared the direct costs, recovery times and satisfaction of 45 patients randomly assigned to two balanced anesthesia groups (sevofluoraneremifentanil group n = 24 or isofluoraneremifentanil group n = 21) submitted to otorhinolaringology surgical procedures. Results: the times of early recovery (ocular opening, answer to commandos, extubación, orientation and room leave) were smaller in ISO group and had statistically significant difference. Variable data was found in acquisition costs of halogenados gastados, lesser for isofluorane, which also made the anesthetic supplies less expensive during surgical procedures; nevertheless, costs in the delivery room, in recovery and ambulatory room, and the total costs did not show significant differences. Satisfaction was similar between both groups. Conclusions: a sevofluorane-remifentanil based technique is not more cost-effective than to use isofluoraneremifentanil for ambulartory patients submitted to otorhinolaringology surgical procedures
Perspectives on the ‘silent period’ for emergent bilinguals in England
This paper draws together the research findings from two ethnographic studies (Drury, 2007; Bligh, 2011) as a means to problematize the ‘silent period’ as experienced by young bilingual learners in two English speaking early years settings in England. Most teachers and senior early years practitioners in England are monolingual English speakers. The children (regardless of their mother tongue) are taught through the medium of spoken and written English in and through all subject areas. Bilingual learning through the mother tongue is not only disregarded in most schools in England but is actively discouraged in some.
Three emergent bilingual learners were re-examined as case studies. Suki and Adyta (Bligh, 2011) of Japanese and Punjabi decent and Nazma (Drury, 2007) of Kashmiri descent were observed whilst they each negotiated new ways of knowing within and through an English pre-school setting. Sociocultural insights into how these young children employ their silenced mother tongue to negotiate their learning creates a fuller and richer portrait of the emergent bilingual learner both in and outside of preschool.
These collaborative research findings present the silent period as agentive (Drury, 2007) and as a crucial time for self-mediated learning (Bligh, 2011) within the early years community of practice
From Bengali to English: sequential bilingualism of a second-generation British Bangladeshi
The paper discusses sequential language acquisition of the researcher's daughter Safa who transformed from a monolingual Bengali speaker to an almost monolingual English speaker in a few months after moving to the UK. Safa was born in Bangladesh and was a monolingual Bengali speaker until she was three years and nine months when the family moved to the UK. Unlike most research on sequential bilingualism, Safa's transition from Bengali to English went through a period of an invented language, which she developed and used for a few months. Safa then underwent language shift as Bengali became her passive language. Safa's loss of fluency in Bengali was mainly due to the absence of Bengali linguistic environment, because her family lived outside the community. Safa's mother's indifference to Bangladeshi ethnicity and her parents’ positive attitude towards Britishness meant that her decline in Bengali did not cause them much concern. Despite the lack of proficiency in Bengali, Safa still retains a strong ethnic Bangladeshi identity. Tabors and Snow’s four-stage developmental process of sequential second-language acquisition has been applied to find the similarities and differences in Safa's case, while language maintenance and shift theories have contributed to the analysis of the process of her language shift
Predictors of reading literacy for first and second language learners
In this study an attempt was made to construct a multi-factor model predicting the development of reading literacy in the upper grades of primary school in the Netherlands for subgroups of 729 first language (L1) learners and 93 second language (L2) learners. Following a longitudinal design, it was explored to what extent the variation in reading literacy development in L1 and L2 from grade 4 to grade 6 can be explained from children’s word decoding, language, mathematics and nonverbal reasoning skills, reading motivation and self confidence as well as their home reading resources. The results showed that L1 and L2 learners differed in reading literacy skills, language, mathematics, and reasoning skills. Structural equation modelling showed that the reading literacy development in both L1 and L2 learners could be explained from decoding, language, mathematics and reasoning skills, as well as their motivation and self-confidence. A striking difference was the fact that home reading resources had an impact on reading literacy in L1 learners but not in L2 learners
Cogeneration, Management decisions for.
This study explores the underlying factors in the decision by private, private non-profit, and public sector facility owners to invest in cogeneration technology. It employs alpha factor analysis techniques to develop factors with maximum generalizability to the universe of variables which potentially explain the decision to invest. Data for this study come from a survey of commercial, industrial, and institutional electric energy consumers who used more than 750 KW demand in any one month of 1981 for a selected electric utility in the Boston area. There were 129 usable responses to the survey(32.2 percent).Cogeneration is the sequential production of thermal energy and electricity at one facility. A technology advocated for its high thermodynamic efficiency compared to separate production of steam and electricity, cogeneration represents an opportunity for a facility owner to substitute capital expenditure today for future operating expenditures. For the past six years, projections of increased cogeneration of electricity and steam consistantly occurred in the literature. In reality, output of steam and electricity from cogeneration plants has declined over the past decade. In the face of contradictions between thermodynamic based projections of cogeneration potential and the reality of declining actual use, most reports offer anecdotal references to market imperfections and non-economic decision variables to justify the contradiction.This study confirms that a number of factors other than purely economic considerations may prevent use of cogeneration technology at the present time. These factors include: Uncertainty caused by regulatory action, Desire for energy self sufficiency by the organization, Financial flexiibility, Experience with electricity cogeneration or self generation, Capital budget planning methodsSecond, this study provides a ranking of the factors involved in the cogeneration decision explaining most variance to least variance. However, the ranking of factors provides no measure of the "importance" of these factors in the decision to adopt or not adopt cogeneration technology.Finally, the results of this study can be used to provide a rough estimate of capacity (KW) and energy (KWH) available from potential cogenerators. This study projects a maximum potential of 106 1MW and 559,000 tIWH of cogenerated electrical energy in the utility service territory between 1982 and 2002
Recommended from our members
Automatic control of electric thermal storage (heat) under real-time pricing. Final report
Real-time pricing (RTP) can be used by electric utilities as a control signal for responsive demand-side management (DSM) programs. Electric thermal storage (ETS) systems in buildings provide the inherent flexibility needed to take advantage of variations in prices. Under RTP, optimal performance for ETS operations is achieved under market conditions where reductions in customers` costs coincide with the lowering of the cost of service for electric utilities. The RTP signal conveys the time-varying actual marginal cost of the electric service to customers. The RTP rate is a combination of various cost components, including marginal generation fuel and maintenance costs, marginal costs of transmission and distribution losses, and marginal quality of supply and transmission costs. This report describes the results of an experiment in automatic control of heat storage systems under RTP during the winter seasons of 1989--90 and 1990--91
Maternal and child predictors of low-income children's educational attainment
Much research has investigated maternal and child predictors of educational attainment. This longitudinal study builds on past research by examining how everyday mother-child conversations about decision-making in early adolescence predict adolescents' decisions to drop out of high school, terminate their education with a high school degree, or complete high school and enroll in tertiary education. Forty-four mothers' use of emotionally enabling speech and willingness to allow their 7th grade children (25 girls; 19 boys) to select their friends predicted children's later decisions about educational attainment in high school. In contrast, children's reported intrinsic motivation, receptive vocabulary scores, and mothers' education did not predict children's educational attainment. These findings underscore the importance of going beyond status variables such as maternal education, to incorporate measures of parent-child interaction in predicting adolescents' educational trajectories. © 2007 Elsevier Inc. All rights reserved
- …