148 research outputs found
In situ optimization methodology for the water circulation pumps frequency of ground source heat pump systems: Analysis for multistage heat pump units
[EN] In order to optimize the global energy performance of a ground source heat pump system, special attention needs to be paid to the auxiliaries as they stand for a considerable part of the total energy consumption. A new in situ experimental methodology based on the frequency variation of the water circulation pumps in order to optimize the energy performance of the system was previously published by the authors for a ground source heat pump system using a single stage heat pump with ON/OFF regulation. The original single stage heat pump was recently replaced with a multistage unit consisting of two compressors of the same capacity working in tandem. A new experimental campaign was carried out and a new study was performed in order to adapt the in situ optimization methodology to the performance of the tandem compressors unit, and, by extension, to the multistage case. This paper presents the in situ optimization methodology for the water circulation pumps frequency adapted for multistage ground source heat pump systems. Results show that energy savings up to 32% can be obtained by applying this optimization methodology.This work was supported by the "Programa de Ayudas de Investigacion y Desarrollo (PAID)" of the Universitat Politecnica de Valencia. This work was also supported by the European FP7 project "Advanced ground source heat pump systems for heating and cooling in Mediterranean climate" (GROUND-MED).Cervera Vázquez, J.; Montagud Montalvá, CI.; Corberán Salvador, JM. (2015). In situ optimization methodology for the water circulation pumps frequency of ground source heat pump systems: Analysis for multistage heat pump units. Energy and Buildings. 88:238-247. https://doi.org/10.1016/j.enbuild.2014.12.008S2382478
Mapped aboveground carbon stocks to advance forest conservation and recovery in Malaysian Borneo
Forest carbon stocks in rapidly developing tropical regions are highly heterogeneous, which challenges efforts to develop spatially-explicit conservation actions. In addition to field-based biodiversity information, mapping of carbon stocks can greatly accelerate the identification, protection and recovery of forests deemed to be of high conservation value (HCV). We combined airborne Light Detection and Ranging (LiDAR) with satellite imaging and other geospatial data to map forest aboveground carbon density at 30m (0.09ha) resolution throughout the Malaysian state of Sabah on the island of Borneo. We used the mapping results to assess how carbon stocks vary spatially based on forest use, deforestation, regrowth, and current forest protections. We found that unlogged, intact forests contain aboveground carbon densities averaging over 200MgCha−1, with peaks of 500MgCha−1. Critically, more than 40% of the highest carbon stock forests were discovered outside of areas designated for maximum protection. Previously logged forests have suppressed, but still high, carbon densities of 60–140MgCha−1. Our mapped distributions of forest carbon stock suggest that the state of Sabah could double its total aboveground carbon storage if previously logged forests are allowed to recover in the future. Our results guide ongoing efforts to identify HCV forests and to determine new areas for forest protection in Borneo
Incorporating kinetic effects on Nernst advection in inertial fusion simulations
We present a simple method to incorporate nonlocal effects on the Nernst advection of magnetic fields down steep temperature gradients, and demonstrate its effectiveness in a number of inertial fusion scenarios. This is based on assuming that the relationship between the Nernst velocity and the heat flow velocity is unaffected by nonlocality. The validity of this assumption is confirmed over a wide range of plasma conditions by comparing Vlasov-Fokker-Planck and flux-limited classical transport simulations. Additionally, we observe that the Righi-Leduc heat flow is more severely affected by nonlocality due to its dependence on high velocity moments of the electron distribution function, but are unable to suggest a reliable method of accounting for this in fluid simulations
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Shared decision-making during childbirth in maternity units: the VIP mixed-methods study
Background
NHS policy emphasises shared decision-making during labour and birth. There is, however, limited evidence concerning how decision-making happens in real time.
Objectives
Our objectives were as follows – create a data set of video- and audio-recordings of labour and birth in midwife-led units; use conversation analysis to explore how talk is used in shared decision-making; assess whether or not women’s antenatal expectations are reflected in experiences and whether or not the interactional strategies used (particularly the extent to which decisions are shared) are associated with women’s postnatal satisfaction; and disseminate findings to health-care practitioners and service users to inform policy on communication in clinical practice.
Design
This was a mixed-methods study. The principal method was conversation analysis to explore the fine detail of interaction during decision-making. Derived from the conversation analysis, a coding frame was developed to quantify interactions, which were explored alongside questionnaire data concerning women’s antenatal expectations and preferences, and women’s experiences of, and postnatal satisfaction with, decision-making. Semistructured interviews with health-care practitioners explored factors shaping decision-making.
Setting and participants
The study took place in midwife-led units at two English NHS trusts. A total of 154 women (aged ≥ 16 years with low-risk pregnancies), 158 birth partners and 121 health-care practitioners consented to be recorded. Of these participants, 37 women, 43 birth partners and 74 health-care practitioners were recorded.
Key findings
Midwives initiate the majority of decisions in formats that do not invite women’s participation (i.e. beyond consenting). The extent of optionality that midwives provide varies with the decision. Women have most involvement in decisions pertaining to pain relief and the third stage of labour. High levels of satisfaction are reported. There is no statistically significant relationship between midwives’ use of different formats of decision-making and any measures of satisfaction. However, women’s initiation of decisions, particularly relating to pain relief (e.g. making lots of requests), is associated with lower satisfaction.
Limitations
Our data set is explored with a focus on decision initiation and responses, leaving other important aspects of care (e.g. midwives’ and birth partners’ interactional techniques to facilitate working with pain) underexplored, which might be implicated in decision-making. Despite efforts to recruit a diverse sample, ethnic minority women are under-represented.
Conclusions
Policy initiatives emphasising patient involvement in decision-making are challenging to enact in practice. Our findings illustrate that women are afforded limited optionality in decision-making, and that midwives orient to guidelines/standard clinical practice in pursuing particular decisional outcomes. Nonetheless, the majority of women were satisfied with their experiences. However, when women needed to pursue decisions, particularly concerning pain relief, satisfaction is lower. Conversation analysis demonstrates that such ‘women-initiated’ decision-making occurs in the context of midwives’ avoiding pharmacological methods of pain relief at particular stages of labour.
Future research
We suggest that future research address the following – the barriers to inclusion of ethnic minority research participants, decision-making in obstetric units, systematic understanding of how pain relief decisions are pursued/resolved, conversation analysis of interactional elements beyond the specific decision-making context, interactional ‘markers’ of the emotional labour and inclusion of antenatal encounters
In situ optimization methodology for ground source heat pump systems: Upgrade to ensure user comfort
[EN] Ground source heat pump systems have been proved to be one of the most efficient systems for heating and cooling in buildings. However, an optimal energy performance depends on a good control of the auxiliaries, which stand for an important part of the total energy consumption. The authors previously developed an experimental in situ optimization methodology for the water circulation pumps frequency of ground source heat pump systems when single stage and multi-stage ON/OFF regulation is employed. However, the user comfort was not completely met under extreme weather conditions during summer. This paper presents the upgrading of this energy optimization strategy combining circulation pumps frequency variation and building supply temperature compensation in order to ensure the user comfort while keeping high energy savings. Experimental results show that the user comfort is met by means of this new methodology and the energy savings (33%) are even higher than those obtained with the previous methodology. (C) 2015 Elsevier B.V. All rights reserved.This work was supported by the "Programa de Ayudas de Investigacion y Desarrollo (PAID)" of the Universitat Politecnica de Valencia. This work was also supported by the European FP7 project "Advanced ground source heat pump systems for heating and cooling in Mediterranean climate" (GROUND-MED).Cervera Vázquez, J.; Montagud Montalvá, CI.; Corberán Salvador, JM. (2015). In situ optimization methodology for ground source heat pump systems: Upgrade to ensure user comfort. Energy and Buildings. 109:195-208. https://doi.org/10.1016/j.enbuild.2015.10.026S19520810
Measuring changes in self-concept: a qualitative evaluation of outcome questionnaires in people having acupuncture for their chronic health problems
BACKGROUND: Changes in self-concept are an important potential outcome for many interventions for people with long-term conditions. This study sought to identify and evaluate outcome questionnaires suitable for quantifying changes in self-concept in people with long-term conditions, in the context of treatment with acupuncture and Chinese medicine. METHODS: A literature search was followed by an evaluation of three questionnaires: The Wellbeing Questionnaire W-BQ12, the Patient Enablement Instrument (PEI), and the Arizona Integrative Outcome Scale (AIOS). A convenience sample of 23 people completed the questionnaires on two occasions and were interviewed about their experience and their questionnaire responses. All acupuncturists were interviewed. RESULTS: Changes in self-concept were common and emerged over time. The three questionnaires had different strengths and weaknesses in relation to measuring changes in self-concept. The generic AIOS had face validity and was sensitive to changes in self-concept over time, but it lacked specificity. The PEI was sensitive and specific in measuring these changes but had lower acceptability. The sensitivity of the W-BQ12 was affected by initial high scores (ceiling effect) and a shorter timescale but was acceptable and is suitable for repeated administration. The PEI and W-BQ12 questionnaires worked well in combination. CONCLUSION: Changes in self-concept are important outcomes of complex interventions for people with long-term illness and their measurement requires carefully evaluated tools and long-term follow-up. The literature review and the analysis of the strengths and weaknesses of the questionnaires is a resource for other researchers. The W-BQ12 and the PEI both proved useful for this population and a larger quantitative study is planned
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