Measurements of the Electrical Incidence Angle Modifiers of an Asymmetrical Photovoltaic/Thermal Compound Parabolic Concentrating-Collector

Reflector edges, sharp acceptance angles and by-pass diodes introduce large variations in the electrical performance of asymmetrical concentrating photovoltaic/thermal modules over a short incidence angle interval. It is therefore important to quantify these impacts precisely. The impact on the electrical performance of the optical properties of an asymmetrical photovoltaic/thermal CPC-collector was measured in Maputo, Mozambique. The measurements were carried out with the focus on attaining a high resolution incidence angle modifier in both the longitudinal and transversal directions, since large variations were expected over small angle intervals. A detailed analysis of the contribution of the diffuse radiation to the total output was also carried out. The solar cells have an electrical efficiency of 18% while the maximum measured electrical efficiency of the collector was 13.9 % per active glazed area and 20.9 % per active cell area, at 25 °C. Such data make it possible to quantify not only the electrical performance for different climatic and operating conditions but also to determine potential improvements to the collector design. The electrical output can be increased by a number of different measures, e.g. removing the outermost cells, turning the edge cells 90°, dividing each receiver side into three or four parts and directing the tracking, when used, along a north-south axis.

Speed profile optimization of catenary-free electric trains with lithium-ion batteries

Catenary-free operated electric trains, as one of the recent technologies in railway transportation, has opened a new field of research: speed profile optimization and energy optimal operation of catenary-free operated electric trains. A well-formulated solution for this problem should consider the characteristics of the energy storage device using validated models and methods. This paper discusses the consideration of the lithium-ion battery behavior in the problem of speed profile optimization of catenary-free operated electric trains. We combine the single mass point train model with an electrical battery model and apply a dynamic programming approach to minimize the charge taken from the battery during the catenary-free operation. The models and the method are validated and evaluated against experimental data gathered from the test runs of an actual battery-driven train tested in Essex, UK. The results show a significant potential in energy saving. Moreover, we show that the optimum speed profiles generated using our approach consume less charge from the battery compared to the previous approaches.

Concept Clarification of Moral Case Deliberation

Background: Health care professionals have encountered ethically difficult situations for decades in their clinical practice. Various clinical ethics support has been established in order to deal with these issues. Moral case deliberation is a new developed approach that deliberates over ethically difficult cases in clinical practice. However, there is lack of knowledge that describes the characteristics of the moral case deliberation and how this differs to related clinical ethics support where a concept analysis may clarify the differences. Aim: To analyse the concept of moral case deliberation and related concepts. Methods: Integrative literature review. Rodger’s evolutionary view of concept analysis has been used for clarification of the concept. Using specific keywords in the databases, searching for peer-reviewed academic paper published in English between 1995-2017 in the CINAHL, MEDLINE, Psych Info, Academic Search Elite and AMED. Results: Moral case deliberation (MCD) was defined as an approach with four specific characteristics: 1) Perspective sharing via dialogue, 2) training moral awareness, 3) moral emotional deliberation, and 4) moral support and joint learning. The presence of a facilitator who is trained in a specific method for the MCD reflection seemed to be important when stimulating the discussion from a patient perspective. Conclusions: Clarify the concept of moral case deliberation can be useful for healthcare professionals when choosing a facilitate-base reflection. Through a mutual dialogue and perspective sharing can MCD train staff members in moral awareness, create a space for emotions to be expressed and finally work as an platform for joint learning.

Depression and Anxiety among Parents of Children with Cystic Fibrosis Related to the Children’s Health Related Quality of Life

The aim was to examine depression and anxiety among parents of children with Cystic Fibrosis and the association between the parents’ symptoms and the child’s quality of life as rated by the parents. Parents completed HADS (Hospital Anxiety and Depression Scale), and CES-D (Center of Epidemiologic Studies Depression Scale), and assessed the children’s quality of life with CFQ-R (Cystic Fibrosis Questionnaire-Revised). Anxiety amongst the parents was higher than the general population (m = 6.55, SD = 3.54, p < 0.001). The level of depression does not differ from that of the general population. Mothers showed more anxiety symptoms than fathers (p < 0.001). Gender differences were not significant for depression symptoms. There is a strong association between the fathers’ self-rated depression and their rating of their child’s health. Both children and parents should be paid attention to in order to identify mental ill-health and take measures in good time.

Testing Bifacial PV Cells in Symmetric and Asymmetric Concentrating CPC Collectors

Bifacial PV cells have the capacity to produce solar electricity from both sides and, thus, amongst other advantages, allow a significantly increase both in peak and annual power output while utilizing the same amount of silicone. According to the manufacturer, the bifacial cells are around 1.3 times more expensive than the single-sided cells. This way, bifacial PV cells can effectively reduce the cost of solar power for certain applications. Today, the most common application for these cells is in stationary vertical collectors which are exposed to sunlight from both sides, as the relative position of the sun changes throughout the day. Another possible application is to utilize these cells in concentrating collectors. Three test prototypes utilizing bifacial PV cells were built. The initial two prototypes were built for indoor testing and differed only in geometry of the reflector, one being asymmetric and the other symmetric. Both prototypes were evaluated in an indoor solar simulator. Both reflector designs yielded positive electrical performance results and similar efficiencies from both sides of the cell were achieved. However, lower fill factor than expected was achieved for both designs when compared to the single cell tests. The results are discussed and suggestions for further testing are presented. A third prototype was built in order to perform outdoor evaluations. This prototype utilized a bifacial PV cells string laminated in silicone enclosed between 2 standard glass panes and a collector box with an asymmetric CPC concentrator. The prototype peak electrical efficiency and temperature dependence were evaluated. A comparison between the performance of the bottom and top sides of the asymmetric collector is also presented. Additionally, the incidence modifier angle (IAM) is also briefly discussed.

Construction of a Small Scale Laboratory for Solar Collectors and Solar Cells in a Developing Country

In the field of renewable energy, self-provided research in developing countries is barely present, but most welcomed. The creation of know-how and self-development of technologies should reduce the dependence on industrialized countries for both materials and knowledge. This work presents technological and social issues related to the construction of a low budget solar laboratory in Mozambique. The goal is to demonstrate that scientific level research can be carried out in developing countries by using affordable solutions without sacrificing quality of the results. For this investigation, a solar laboratory was built in 2011 at Universidade Eduardo Mondlane of Maputo. The laboratory enables measurements?to evaluate solar?thermal and?photovoltaic-thermal?hybrid collectors.?Thanks to the?flexibility of the system,?students and teaching staff can?add/remove equipment and develop customised local research programs. In addition, a course on the principles of solar energy and collector simulation for local students was taught. The needed data acquisition devices usually used in Europe were compared with cheaper and easy-maintenance ones. Calibration and estimation of the uncertainty were successfully performed. Approximately 9% of inaccuracy in the measurement was introduced by the cheaper equipment, but the investment cost was reduced by more than 90%. Other issues, results and future recommendations are shown.

Images of sorrow—Experiences of losing a co-twin in old age

What it is like when a lifelong twin relationship ends through death in later life is the focus of this study. It draws on interview data from seven twins who are part of a longitudinal Swedish twin study (SATSA) and who lost their co-twins in old age. Data were analyzed using qualitative latent content analysis. The results showed that the experience of loss of the co-twin was profound, including an emotional as well as a behavioral dimension. Loss and loneliness were expressed as the dominant feelings related to the quality of the missing relationship as well as the loss of twin identity. However, the grief experiences in this study were primarily related to the closeness and quality of the twin relationship, rather than identity. Behavioral adjustments included the use of outside as well as internal cognitive resources to cope with life after the loss. Despite the devastating experience of losing a co-twin after a lifelong relationship, the participants engaged actively in their own grief processes. It was concluded that twin loss is unique, in the sense of losing the relational twin identity, as well as it is characterized by similar features as the loss of a close relationship among non-twins.

Applications of AI in advanced energy storage technologies

The prompt development of renewable energies necessitates advanced energy storage technologies,which can alleviate the intermittency of renewable energy.In this regard,artificial intelligence(AI)is a promising tool that provides new opportunities for advancing innovations in advanced energy storage technologies(AEST).Given this,Energy and AI organizes a special issue entitled“Applications of AI in Advanced Energy Storage Technologies(AEST)”.

Optimal Planning of Community Integrated Energy Station Considering Frequency Regulation Service

With the extensive integration of high-penetration renewable energy resources,more fast-response frequency regulation(FR)providers are required to eliminate the impact of uncertainties from loads and distributed generators(DGs)on system security and stability.As a high-quality FR resource,community integrated energy station(CIES)can effectively respond to frequency deviation caused by renewable energy generation,helping to solve the frequency problem of power system.This paper proposes an optimal planning model of CIES considering FR service.First,the model of FR service is established to unify the time scale of FR service and economic operation.Then,an optimal planning model of CIES considering FR service is proposed,with which the revenue of participating in the FR service is obtained under market mechanism.The flexible electricity pricing model is introduced to flatten the peak tieline power of CIES.Case studies are conducted to analyze the annual cost and the revenue of CIES participating in FR service,which suggest that providing ancillary services can bring potential revenue.

The development of China's Yangtze River Economic Belt:how to make it in a green way?

The Yangtze River is one of the largest and longest rivers in Asia.The river originates in the Tibet-Qinghai Plateau(headwater reach),passes through the mountainous provinces of Sichuan,Yunnan and Chongqing(upper reach),flows into the Central Plain(middle reach)and Lower Plain(lower reach),and finally empties into the East China Sea in Shanghai(estuary).The Yangtze River Economic Belt(YREB;Fig.1)has a surface area of 2.1

Methane mitigation: Learning from the natural marine environment

During the past decades,public attention regarding global warming has mainly focused on CO_(2) reduction;however,CH4,another important greenhouse gas,has a global warming potential that is 84 times higher than that of CO_(2) on a 20-year basis.The annual atmospheric amount of CH4 in 2020 reached its highest level since systematic monitoring began in 1983(Figure 1A).To date,despite coronavirus 2019 shutdowns,methane has contributed approximately 30%to global warming.Recently,a series of timely appeals,such as“The Global Methane Pledge”signed at the United Nations Climate Change Conference(COP26)and the“Global Methane Assessment”from the United Nations Environment Program,have called on global methane reduction and mitigation.

A data-driven approach for predicting long-term degradation of a fleet of micro gas turbines

Predictive health monitoring of micro gas turbines can significantly increase the availability and reduce the operating and maintenance costs.Methods for predictive health monitoring are typically developed for large-scale gas turbines and have often focused on single systems.In an effort to enable fleet-level health monitoring of micro gas turbines,this work presents a novel data-driven approach for predicting system degradation over time.The approach utilises operational data from real installations and is not dependent on data from a reference system.The problem was solved in two steps by:1)estimating the degradation from time-dependent variables and 2)forecasting into the future using only running hours.Linear regression technique is employed both for the estimation and forecasting of degradation.The method was evaluated on five different systems and it is shown that the result is consistent(r>0.8)with an existing method that computes corrected values based on data from a reference system,and the forecasting had a similar performance as the estimation model using only running hours as an input.