25 resultados para Electricity in dentistry
Resumo:
Using a unique set of data and exploiting a large-scale natural experiment, we estimate the effect of real-time usage information on residential electricity consumption in Northern Ireland. Starting in April 2002, the utility replaced prepayment meters with advanced meters that allow the consumer to track usage in real-time. We rely on this event, account for the endogeneity of price and payment plan with consumption through a plan selection correction term, and find that the provision of information is associated with a decline in electricity consumption of 11-17%. We find that the reduction is robust to different specifications, selection-bias correction methods and subsamples of the original data. The advanced metering program delivers reasonably cost-effective reductions in carbon dioxide emissions, even under the most conservative usage reduction scenarios.
Resumo:
This paper investigates the impacts of offshore wind power forecast error on the operation and management of a pool-based electricity market in 2050. The impact from offshore wind power forecast errors of up to 2000 MW on system generation costs, emission costs, dispatch-down of wind, number of start-ups and system marginal price are analysed. The main findings of this research are an increase in system marginal prices of approximately 1% for every percentage point rise in the offshore wind power forecast error regardless of the average forecast error sign. If offshore wind power generates less than forecasted (−13%) generation costs and system marginal prices increases by 10%. However, if offshore wind power generates more than forecasted (4%) the generation costs decrease yet the system marginal prices increase by 3%. The dispatch down of large quantities of wind power highlights the need for flexible interconnector capacity. From a system operator's perspective it is more beneficial when scheduling wind ahead of the trading period to forecast less wind than will be generated.
Resumo:
OBJECTIVES: The aim of this study was to investigate if a minimally invasive oral health package with the use of atraumatic restorative treatment (ART) or a conventional restorative technique (CT) would result in any perceived benefit from the patients' perspective and if there would be any difference between the two treatment groups.
MATERIALS AND METHODS: In this randomised clinical trial, 99 independently living older adults (65-90 years) with carious lesions were randomly allocated to receive either ART or conventional restorations using minimally invasive/intervention dentistry (MID) principles. Patients completed an Oral Health Impact Profile (OHIP)-14 questionnaire before and 2 months after treatment. They were also asked to complete a global transition question about their oral health after treatment.
RESULTS: At baseline, the mean OHIP-14 scores recorded were 7.34 (ART) and 7.44 (CT). Two months after treatment intervention, 90 patients answered the OHIP-14 and the mean scores were 7.23 (not significant (n.s.)) and 10.38 (n.s.) for the ART and CT groups, respectively. Overall, 75.5 % of patients stated that their oral health was better compared to the beginning of treatment.
CONCLUSIONS: Although not shown by the OHIP-14, patients perceived an improvement in their overall oral status after treatment, as demonstrated by the global transition ratings in both groups.
CLINICAL RELEVANCE: Dental treatment using minimally invasive techniques might be a good alternative to treat older individuals, and it can improve their oral health both objectively and subjectively.
Resumo:
The European Union has set a target for 10% renewable energy in transport by 2020 to be met using biofuels and electric vehicles. In the case of biofuels, the biofuel must achieve greenhouse gas savings of 35% relative to the fossil fuel replaced. For biofuels, greenhouse gas savings can be calculated using life cycle analysis or the European Union default values. In contrast, all electricity used in transport is considered to be the same, regardless of the source or the type of electric vehicle. However, the choice of the electric vehicle and electricity source will have a major impact on the greenhouse gas saving. In this paper the initial findings of a well-to-wheel analysis of electric vehicle deployment in Northern Ireland are presented. The key finding indicates that electric vehicles require least amount of energy per mile on a well-to-wheel basis, consume the fewest resources, even accommodating inefficient fuel production, in comparison to standard internal combustion engine and hybrid vehicles.
Resumo:
Throughout the world the share of wind power in the generation mix is increasing. In the All Island Grid, of the Republic of Ireland and Northern Ireland there is now over 1.5 GW of installed wind power. As the penetration of these variable, non-dispatchable generators increases, power systems are becoming more sensitive to weather events on the supply side as well as on the demand side. In the temperate climate of Ireland, sensitivity of supply to weather is mainly due to wind variability while demand sensitivity is driven by space heating or cooling loads. The interplay of these two weather-driven effects is of particular concern if demand spikes driven by low temperatures coincide with periods of low winds. In December 2009 and January 2010 Ireland experienced a prolonged spell of unusually cold conditions. During much of this time, wind generation output was low due to low wind speeds. The impacts of this event are presented as a case study of the effects of weather extremes on power systems with high penetrations of variable renewable generation.
Resumo:
Natural gas (NG) network and electric network are becoming tightly integrated by microturbines in the microgrid. Interactions between these two networks are not well captured by the traditional microturbine (MT) models. To address this issue, two improved models for single-shaft MT and split-shaft MT are proposed in this paper. In addition, dynamic models of the hybrid natural gas and electricity system (HGES) are developed for the analysis of their interactions. Dynamic behaviors of natural gas in pipes are described by partial differential equations (PDEs), while the electric network is described by differential algebraic equations (DAEs). So the overall network is a typical two-time scale dynamic system. Numerical studies indicate that the two-time scale algorithm is faster and can capture the interactions between the two networks. The results also show the HGES with a single-shaft MT is a weakly coupled system in which disturbances in the two networks mainly influence the dc link voltage of the MT, while the split-shaft MT is a strongly coupled system where the impact of an event will affect both networks.
Resumo:
Throughout the European Union there is an increasing amount of wind generation being dispatched-down due to the binding of power system operating constraints from high levels of wind generation. This paper examines the impact a system non-synchronous penetration limit has on the dispatch-down of wind and quantifies the significance of interconnector counter-trading to the priority dispatching of wind power. A fully coupled economic dispatch and security constrained unit commitment model of the Single Electricity Market of the Republic of Ireland and Northern Ireland and the British Electricity Trading and Transmission Arrangement was used in this study. The key finding was interconnector counter-trading reduces the impact the system non-synchronous penetration limit has on the dispatch-down of wind. The capability to counter-trade on the interconnectors and an increase in system non-synchronous penetration limit from 50% to 55% reduces the dispatch-down of wind by 311 GW h and decreases total electricity payments to the consumer by €1.72/MW h. In terms of the European Union electricity market integration, the results show the importance of developing individual electricity markets that allow system operators to counter-trade on interconnectors to ensure the priority dispatch of the increasing levels of wind generation.
Resumo:
Background: Upon completion of Specialty Training in Restorative Dentistry, trainees (StRs) should
be proficient in maxillofacial prosthodontics to meet the restorative needs of head and neck cancer patients (HANC), and in preparation for the Intercollegiate Specialty Fellowship Examination (ISFE).1,2
Objective: The aim of this study is to collate and compare data relating to the training of Restorative Dentistry Rs in the management of HANC patients across different geographical locations within the British Isles. Methods: Current trainees were invited to complete an online questionnaire by the Specialty Registrars in Restorative Dentistry Group (SRRDG). Participants were asked to rate their confidence and experience in assessing and planning treatment for HANC patients, attending theatre and manufacturing surgical obturators, and in providing implants for appropriate cases. Respondents were also asked to appraise clinical and didactic teaching within their unit, and to rate their confidence of passing oncology- based questions in a future ISFE. Results: Responses were obtained from 21 StRs (n=21) training in all five countries within the British Isles. Most respondents were based in England (76%). A third were in their 5th year of training. Less than half reported that they were confident
of independently assessing (48%) or treatment planning (38%) HANC patients. More than half of StRs (52%) indicated that they were not confident of attending theatres alone and manufacturing a surgical obturator. One third (33%) rated their experience of treating oncology patients with implants as poor or very poor, including three in their 5th year of training. Less than one third rated didactic teaching in maxillofacial prosthodontics at their unit as good or excellent. Only 4 respondents indicated that they were confident of answering an ISFE oncology question on management of healthcare delivery. Six StRs expressed concerns over a lack of case-based exposure.
Conclusion: Experience and training in maxillofacial prosthodontics is inconsistent for StRs across the British Isles with many lacking in clinical exposure.
Resumo:
Objectives: To explore the content and methodology of predoctoral Geriatric Dentistry teaching amongst European dental schools.
Methods: The study was conducted by the European College of Gerodontology (ECG) Education Committee. Αn electronic questionnaire has been developed with close and open-ended items, including information on the prevalence and institutional anchorage of Gerodontology programs, the educators, the content and the methodology of teaching. An electronic mail, including a hyperlink to the questionnaire, was sent to 216 dental schools in 39 European countries (Winter/ Spring 2016). The Deans were asked to either answer themselves, or forward the link to faculty members with knowledge on Gerodontology teaching at their respective schools. Repeated reminders or telephone calls were used for non-respondents and personal networks were exploited to identify potential contact persons.
Results: Until August 2016, 121 dental schools from 29 countries responded to the survey (response rate 56%, EU response rate: 60%). Gerodontology was included in the predoctoral curricula of 86% of the respondents and was compulsory in 68%. The course was mainly offered in senior students and was interdisciplinary in 30% of the schools, delivered mainly by dentists (79%), physicians (21%), psychologists (10%), and nurses (5%). It was conducted as an independent lecture series in 40% of the schools and a course director was assigned in 44% of the respondents. When embedded in other disciplines, these were mainly Prosthodontics (31%). The content included a large number of items, such as epidemiology of oral health, medical problems in old age, prosthodontic management, xerostomia, and caries risk assessment. Lectures were the most common teaching format (69%), followed by small group seminars (27%). The most common types of educational material used were scientific articles (48%), printed textbooks (44%), lecture notes (40%) and e-learning material (21%). Clinical training was offered by 64% of the respondents, within the dental school clinics (49%) and/or in outreach locations (40%).
Conclusion: Amongst the respondent European dental schools (66%) there is an increasing number that teach Gerodontology at a pre-doctoral level with significant variations in content and methodology. Official guidelines and the dissemination of the ECG pre-doctoral curriculum guidelines might help to increase the prevalence and improve the status of Gerodontology teaching in Europe.